JP4900974B2 - Anesthetic gas regeneration method and apparatus - Google Patents

Description

  The present invention relates to the handling of waste anesthetic gas produced in one or more anesthesia supply systems in medical or other facilities using medical, dental or veterinary inhalation anesthesia. In order to prevent air pollution, the present invention relates to the removal and regeneration of nitrous oxide, fluoroethers and other halocarbons from a waste anesthetic gas stream prior to venting to the atmosphere.

  In anesthesia supply systems in the surgical field (medical, dental and veterinary), a large amount of waste anesthetic gas is generated. Currently, these gases are collected from the patient's breath by a dedicated or shared vacuum system. In a medical facility, waste gas is collected from each anesthesia site, typically using one or more centrally located vacuum pumps. These vacuum pumps are usually excessively large because they are designed to collect exhaled anesthetic gas over a wide range of flow rates. Since the pump is operated continuously, the waste anesthetic gas suction system entrains a large amount of air in the surrounding room from the anesthesia site and greatly dilutes the waste anesthetic gas. In central vacuum pumps, the gas stream is often further mixed with the atmosphere and further diluted before it is exhausted from the system. This diluted waste anesthetic gas / air mixture is typically pumped to a location outside the surgical facility where it is released to the atmosphere.

  Waste anesthetic gas is usually collected at about 20-30 ° C. and 10-60 percent relative humidity. The average composition of the waste gas is 25-32 percent oxygen, 60-65 percent nitrogen, 5-10 percent nitrous oxide, 0.1-0.5 percent volatile halocarbon in volume percent. Thus, it is presumed to contain fluoroethers such as isoflurane, desflurane, sevoflurane and the like. The waste anesthetic gas may contain a small amount of lubricating oil vapor from the vacuum pump.

  Waste anesthetic gas halocarbon (compositionally similar to Freon 12 (Freon is a registered trademark) and other refrigerants) as a cause of increasing environmental concerns is the ozone depletion and less serious Is related to global warming. Halocarbons (mainly halogenated methyl ethyl ethers) used for anesthesia are now significant as the release of other industrial and commercial halocarbons has been significantly reduced by law and other guidance in recent years. It is a release source. Although the release of waste anesthetic gas is currently exempt from environmental regulations in the United States, a legal movement to strictly control the release of waste anesthetic gas is likely to occur in the near future.

  Various techniques for treating waste anesthetic gas have been proposed to prevent the problem of waste anesthetic gas release from becoming significant. For example, US Pat. No. 4,259,303 discloses treating laughing gas with a catalyst and US Pat. No. 5,044,363 discloses absorbing anesthetic gas with fine charcoal. US Pat. No. 5,759,504 discloses the decomposition of anesthetic gas by heating in the presence of a catalyst, and US Pat. No. 5,928,411 discloses absorption of the anesthetic gas with molecular sieves. U.S. Pat. No. 6,134,914 discloses the separation of xenon from exhaled anesthetic gas. A low temperature process for flushing volatile halocarbons from waste anesthetic gas is disclosed by Berry in US Pat. No. 6,729,329, incorporated herein by reference.

  FIG. 1 illustrates a prior art representative waste anesthetic gas regeneration system 10 for a health care facility. The system 10 includes a number of separate anesthesia stations 15A, 15B, 15C, each having anesthesia facilities 12A, 12B, 12C, and anesthesia facilities 12A, 12B, 12C that receive anesthetics. Delivered to the patient via masks 14A, 14B, 14C or similar devices. Excess anesthetic gas, patient exhaled air and air are collected by the anesthesia equipment 12A, 12B, 12C at the masks 14A, 14B, 14C and discharged to the common collection manifold 16. The waste anesthetic gas collection manifold 16 is typically tightly plumbed into the medical facility, and the anesthesia equipment 12A, 12B, 12C is connected to a standard waste anesthetic gas connector 18A, 18B, 18C, such as a 19 mm or 30 mm anesthesia connector. And is removably connected to the collection manifold 16. The waste anesthetic gas regeneration system 10 is operated at a vacuum pressure generated by one or more central vacuum pumps 20. The collected waste gas stream is typically sent through a check valve 35 to a condenser unit 22 comprised of one or more heat exchangers. A liquid oxygen absorber, or other suitable heat sink, extracts heat from the waste anesthesia stream and liquefies the anesthetic gas component. Liquid waste anesthetic condensate is collected in collection container 24, and liquid moisture condensate is collected in collection container 23. The remaining gas stream, from which the waste anesthetic gas component has been removed, passes through the receiver 26B and the vacuum pump 20, and then is vented through the vent 46 to the atmosphere outside the medical facility.

  The latest method of collecting waste anesthetic gas from anesthesia sites 15A, 15B, 15C in a medical facility is generally to draw the atmosphere into a dedicated or shared vacuum collection manifold 16 at a high flow rate and accompany the waste anesthetic gas It is. The collection manifold 16 also continuously draws air through a number of resting anesthesia devices 12A, 12B, 12C. On average, the collection system manifold 16 draws about 20-30 liters of waste anesthetic gas and / or atmosphere at each anesthesia site 15A, 15B, 15C per minute. In a large hospital having 20 to 30 operating rooms, the flow rate of the waste anesthetic gas regeneration system 10 is in the range of 500 to 1000 l / min (14 to 35 scf / min).

The advantages of a large flow dilution waste gas system are that it easily accommodates a wide range of anesthetic discharge flow rates, is relatively safe because little anesthesia is dissipated from the system, and is relatively free because little maintenance is required. There is no worry of breakdown. However, large flow systems are energy intensive and typically require a large vacuum pump 20 to maintain sufficient inspiration at multiple anesthesia sites 15A, 15B, 15C. For example, to maintain a vacuum of about 26664 Pa (200 mm Hg) at a flow rate of 0.0283 to 0.0566 m ³ (1-2 cubic feet per minute (cfm)) in each of anesthesia stations 15A, 15B, 15C A vacuum pump with a capacity of 2.83 to 5.66 m ³ (100 to 200 cfm) per minute is not common. Therefore, a small-flow waste anesthetic gas collection system that safely concentrates the waste anesthetic gas is preferable.

  Furthermore, the diluted waste anesthetic gas flow is thermally inefficient. Removing the waste gas component by liquefaction requires that the temperature of the flow at full flow rate be reduced to a point where the partial pressure of the gaseous waste component is greater than or equal to the saturated vapor pressure (at that temperature). Thus, a fairly large cooling facility is required to cool a large volume of diluted waste anesthetic gas to a temperature below its component's saturated vapor pressure.

  Typically, anesthetic gas is a fairly volatile substance. At a given temperature, the anesthetic gas has a vapor pressure higher than that of water and other less volatile substances. High vapor pressure materials usually require more cooling to obtain condensate recovery that is equivalent or similar to low vapor pressure materials. Thus, the anesthetic gas must be cooled to a very low temperature, for example a very low temperature, in order to recover a substantial amount of anesthesia as a condensate. However, such a very low temperature approaches the freezing point of various anesthetics and in many cases is a lower temperature. In such situations, the waste anesthetic gas stream still contains an anesthetic concentrate that can condense, besides improper freezing of the system.

  Pressure as well as temperature can greatly affect liquefaction. Increasing the pressure of the liquefaction system is advantageous. This is because liquefaction occurs at a much higher temperature than occurs at low operating pressures. This also avoids the risks and problems associated with freezing the condensate. In such gas phase / liquid phase equilibrium systems, the most beneficial thermodynamic property is that pressure has a much greater impact on the gas dew point than the liquid freezing point. Thus, the dew point temperature of a typical anesthetic-containing vapor stream increases with increasing pressure while keeping its freezing point relatively constant for various pressures.

  As the temperature range between the vapor dew point and the condensate freezing point widens due to system pressure rise, the liquefaction system becomes more flexible in operation. For example, since liquefaction occurs at higher temperatures, less refrigerant is required to produce the same amount of condensate. Furthermore, the system temperature can be lowered while maintaining the elevated pressure if it is desired to more completely separate the anesthetic from the waste gas stream. This allows further liquefaction of the anesthetic agent from the gas phase without the attendant risk of condensate freezing. Thus, a strategy is achieved to achieve optimal anesthetic separation simply by adjusting the pressure of the liquefaction system relative to the temperature of the liquefaction system. Of course, relative cooling versus compression costs can also be considered in a cost optimization strategy.

  Although using a low flow waste anesthesia gas collection system and increasing the pressure of the gas flow prior to liquefaction improves both the effectiveness and efficiency of waste anesthesia gas regeneration, such systems and methods still remain medical. It must be integrated with the facility's existing utility equipment. As mentioned above, these prior art systems are typically designed for the removal of large amounts of waste anesthetic gas. For example, the vacuum pumps, ducts, valves, etc. of such existing waste gas removal systems have been sized to handle a large amount of air entrained with waste anesthetic gas. Combining a more efficient anesthetic collection component with an overly large waste air treatment system does not necessarily give the best possible results. Therefore, an appropriately designed waste air treatment system that handles an assumed volume of waste gas is also desired.

  Moreover, the tremendous increase in the use of conventional anesthesia outside hospitals creates additional challenges. Anesthetic gases used in small offices must still be handled properly. However, existing waste anesthetic gas collection and regeneration used in hospitals is impractical for use in small offices due to their overall size and operating costs. Most waste anesthetic gases used in small offices are simply released into the atmosphere (or into the cab) without processing and / or attempting to regenerate valuable anesthetic components. Thus, a self-contained waste anesthetic gas collection and regeneration system that has the same advantages and / or features as a much larger system used in hospitals and other conventional medical facilities is intended for such small individual offices. It is desired.

  The main objective of the present invention is to remove fluoroethers, nitrous oxides and other volatile halocarbons from waste anesthetic gases from surgery or other medical facilities before they are released to the atmosphere. It is to provide an economical apparatus and method.

  Another object of the present invention is to prevent the release of waste anesthetic gas fluoroethers and other volatile halocarbons to the atmosphere while eliminating the need for prior art catalysts, fine charcoal and heating means. It is to provide a system and method.

  Another object of the present invention is to reduce the release of anesthesia-related halocarbons from medical facilities to the atmosphere by 99 percent or more.

  Another object of the present invention is to provide a system and method that regenerates a large percentage of nitrous oxide and / or anesthetic halocarbons used in medical facilities to enable redistillation and / or reuse. is there.

  Another object of the present invention is to provide a system and method that requires minimal additional investment to be implemented by a medical facility.

  Another object of the present invention is to provide an economical system and method for utilizing and enhancing an existing waste anesthetic gas regeneration system in a medical facility with minimal impact and cost.

  Another object of the present invention is to provide an economical system and method that uses existing liquefied gas storage and delivery systems to improve the overall energy efficiency of medical facilities.

  It is another object of the present invention to provide an economical system and method that uses existing liquefied gas storage and transport systems to minimize the impact of installing a medical facility regeneration system.

  Another object of the present invention is to provide a system and method for separating various removed nitrous oxide, fluoroether and other volatile halocarbon components based on their physical properties such as bubble point and dew point. It is to be.

  Another object of the present invention is to provide an economical system and method that improves the effectiveness and efficiency of a liquefied type waste anesthesia removal system.

  Another object of the present invention is to operate a liquefied waste anesthesia collection system under varying pressures and temperatures, thereby improving the effectiveness and efficiency of the liquefied waste anesthesia collection system. And to provide a way.

  Another object of the present invention is to provide a system and method that regenerates anesthetic gas from a waste anesthetic gas stream and does not need to be integrated with an existing waste anesthetic gas regeneration system in a medical facility.

  Another object of the present invention is to provide a system and method that regenerates anesthetic gas from a waste anesthetic gas stream and has minimal dependence on medical facility utility equipment and supplies.

  Other objects, features and advantages of the present invention will be apparent to those skilled in the art from the following detailed description and drawings.

  The above objective, together with other advantages and features, is suitably embodied in a system and method for removing fluoroether, nitrous oxide and volatile halocarbon gas components from waste anesthetic gas, the system and method comprising: One or more of: a low flow anesthesia gas removal unit, a batch mode frost separation process for collecting waste anesthetic gas as frost on the cold trap / divider cooling surface, a compressor having at least one compression stage, and a medical facility Self-contained unit that requires minimal coupling between utility equipment and supplies.

  In a first embodiment, a small flow removal or regeneration system is disclosed that includes a number of intelligent waste anesthesia gas collection units, one of which is located on an individual anesthesia device in a medical or surgical facility, Fluidly connected to a shared collection manifold. Each intelligent waste anesthesia gas collection unit is associated with a collection chamber and an exhaust valve that selectively isolates the intake side of the collection manifold at the corresponding anesthesia station when no waste anesthesia gas is being generated, and an associated operation of the exhaust valve Includes sensors, circuits, control mechanisms or mechanisms.

  Waste anesthetic gas enters the collection chamber through the standard anesthetic waste gas connector from the anesthetic device exhaust. A highly sensitive pressure sensor is preferably disposed within the collection chamber, and the sensor is electrically coupled to a solenoid operated exhaust valve disposed on the exhaust side of the collection chamber. The pressure measured by the pressure sensor is the difference between the pressure in the collection chamber and the outside atmospheric pressure. When the pressure in the collection chamber is higher than atmospheric pressure, the increased pressure is detected by the sensor and the control circuit opens the discharge valve, resulting in a rapid decrease in the pressure in the collection chamber. When the pressure in the collection chamber approaches atmospheric pressure, the pressure sensor detects a pressure drop and closes the discharge valve.

  The collecting circuit is preferably a low voltage direct current circuit and the discharge valve is preferably configured as a normally open valve. A mechanical vacuum breaker and a mechanical pressure relief valve are provided in the collection chamber for safety.

  The pressure detector, exhaust valve, and the circuit between them may be selected and designed to respond proportionally to pressure fluctuations in some cases, with the exhaust valve increasing slightly to a small pressure increase It opens greatly against. In alternative embodiments, the pressure sensor can be pneumatically or mechanically coupled to the exhaust valve for control of the exhaust valve and / or the intelligent waste anesthetic gas collection unit can be connected to the medical facility waste anesthetic gas. Instead of being coupled to a collection manifold, it can also be incorporated into an improved anesthetic device. Thus, the improved anesthesia device includes a prior art anesthesia device and an intelligent waste anesthesia gas collection unit according to embodiments of the present invention.

  Isolating from the atmosphere entrained with the collection manifold when no waste anesthetic gas is being generated reduces the average anesthetic gas collection flow by approximately 90 percent, thus requiring a vacuum pump, piping, and other associated equipment Reduce the maximum capacity.

  In a second embodiment, a batch mode fractionation process is disclosed where the temperature and pressure of fluoroethers and other anesthetic halocarbons are reduced by vapor condensation (deposition) using cryogenic trap or liquid air trap technology. Lower to the point where it collects as frost on the trap / shunt cooling surface. In other words, fluoroethers and other anesthetic halocarbon components in the waste anesthetic gas solidify onto the cooling coil of the heat exchanger by cooling and remove those components from the exhaust gas. The cooling source is preferably liquid oxygen, which is available in surgical facilities such as hospitals and outpatient clinics and usually has to be warmed for daily use. However, other liquefied gases such as liquid nitrogen are also commonly provided in medical facilities and can be used equally as a cooling source.

  The cold trap / shunt is periodically switched off during the thawing stage, during which the cooling surface, thickly covered with frosted gas components captured from the waste anesthetic gas passing through the cooling surface, Gradually warm up and separate and collect the resulting components. At sufficiently high pressures (ie typically above atmospheric pressure), the captured fluoroethers and other anesthetic halocarbons melt and, depending on their physical properties, the liquefied components are drained to another tank. The At sufficiently low pressures (ie, typically below atmospheric pressure), captured fluoroethers and other anesthetic halocarbons do not liquefy and sublime directly into the gas phase. The anesthetic vapor regenerated in this way is preferably collected via a gaseous anesthetic collection system for further processing. The remainder of the anesthetic gas is preferably released to the atmosphere.

  In a third embodiment, a compressor having at least one compression stage is used to increase the pressure of the waste anesthetic gas stream prior to anesthetic regeneration by liquefaction. It is beneficial to compress the waste anesthetic gas to a level above atmospheric pressure. This is because, when the pressure is high, the temperature at which the anesthetic gas is saturated and liquefied basically increases. Thus, by compressing the gas to a pressure higher than atmospheric pressure, the fraction that would be generated by liquefaction at atmospheric pressure and low temperature and the anesthetic agent in the same fraction can be separated by higher temperature liquefaction. Furthermore, as the temperature of the compressed waste anesthetic gas falls from this high temperature, more fractions of the anesthetic will liquefy from the vapor phase. Simply manipulating the liquefaction system pressure in relation to the liquefaction system temperature can create a strategy to achieve optimal separation of the anesthetic agent. Furthermore, energy and cost savings are possible if relative cooling versus compression costs are incorporated into the strategy.

  In a preferred embodiment of the invention, a compressor unit consisting of one or more compression stages is arranged between the waste anesthetic gas collection unit and the liquefaction unit in the waste anesthetic gas collection system. The compressor unit is sized to compress the waste anesthetic gas from the collection unit to 345 kPa (50 psig) to prepare for the next process, the next process being a condensation system, a refrigerant, ie a hospital or other medical facility This is done using liquid oxygen, liquid nitrogen, etc. supplied by a dental or veterinary facility. In an alternative embodiment, the waste anesthetic gas stream is compressed to a pressure well above 345 kPa, taking advantage of the separation efficiency and the concomitant increase in fraction extraction. However, in this alternative embodiment, it is desirable to supply a separate refrigerant to the capacitor to avoid the risk of contaminating the medical facility gas supply if an internal leak occurs in the capacitor.

  In the fourth embodiment, a self-contained waste anesthesia gas regeneration unit that is minimally dependent on utility equipment and medical facility supplies is disclosed. The unit only needs power to operate, a source of waste anesthetic gas, and an outlet to the atmosphere. Thus, the unit can easily be accommodated in a small surgical center such as an operating room, a small animal hospital or a dental clinic. The system / method uses a small cooling unit that cools an intermediate heat transfer fluid, such as DuPont's Suva® 95 or similar low temperature refrigerant, to a temperature of about -90 ° C. To do. In a preferred embodiment of the present invention, the waste anesthetic gas passes through a multi-stage condenser / heat exchanger where the heat from the waste anesthetic gas stream is heat exchanged with an intermediate heat transfer fluid cooled in a small cooling unit. The Thus, the system / method does not rely on the supply of liquid oxygen or liquid nitrogen from a medical facility to provide the necessary low temperature cooling for the waste anesthetic gas flow. However, if desired, liquid oxygen or liquid nitrogen from a medical facility may be used in the heat exchanger / condenser as an intermediate heat transfer fluid.

  The present invention will be described in detail below based on an embodiment shown in the accompanying drawings.

  FIG. 2 illustrates a preferred embodiment of a low flow waste anesthetic gas collection and regeneration system 11 according to the present invention. The regeneration system 11 includes an intelligent waste anesthesia gas collection unit 30A, 30B, 30C located at or near each anesthesia site 15A, 15B, 15C of the medical facility, with the exception of the prior art disposal of FIG. It is almost equivalent to the reproduction system 10. The intelligent waste anesthetic gas collection units 30A, 30B, 30C are preferably fluidly coupled to respective legs of the collection manifold 16 near the standard waste anesthetic gas connectors 18A, 18B, 18C. Each intelligent gas collection unit 30A, 30B, 30C includes a collection valve 32A, 32B, 32C and an exhaust valve that selectively isolates the intake of the collection manifold 16 when no waste anesthetic gas is being generated at the respective anesthesia site. 34A, 34B, 34C and associated sensors, circuits, control mechanisms or mechanisms for operating the discharge valves 34A, 34B, 34C. The collection chamber 32 may be hard, soft (eg, a stretchable bag), or a combination thereof.

  Isolating from the atmosphere entrained with the collection manifold 16 when no waste anesthetic gas is being generated, reduces the average anesthetic collection flow by approximately 90%, thus necessitating vacuum pumps, piping and other associated equipment Reduce the maximum capacity. Thus, for large hospitals with 20-30 operating rooms, the waste anesthetic gas flow rate of 500-1000 l / min with the prior art regeneration system 10 of FIG. 1 is shown in FIG. 2 according to the preferred embodiment of the present invention. It is estimated that the reproduction system 11 decreases to 50 to 100 l / min. The regeneration system 11 described above only requires the addition of individual intelligent waste anesthesia gas collection units 30A, 30B, 30C to the existing medical waste anesthesia gas regeneration system 10, thus making the current system simple and inexpensive. The means for improving the function is provided.

  FIG. 3 illustrates a separate intelligent waste anesthetic gas collection unit 30 according to a preferred embodiment of the present invention. Referring to FIG. 3, waste anesthetic gas enters the chamber 32 from the anesthetic device 12 through a standard waste anesthetic gas connector 18, 19 mm, 30 mm or similar. Within the chamber 32 is a highly sensitive pressure gauge 40 that is electrically coupled to a solenoid driven exhaust valve 34 disposed on the outlet side of the chamber 32. The pressure measured by the pressure gauge 40 is the difference between the pressure in the chamber 32 and the outside air (atmosphere) pressure. When the pressure in the chamber 32 becomes slightly higher than the atmosphere, the increased pressure is detected by the pressure gauge 40, and the discharge valve 34 is opened by the control circuit. Opening the valve 34 fluidizes the chamber 32 with the vacuum source of the collection manifold 16 and the pressure in the chamber 32 drops rapidly. As the chamber pressure approaches atmospheric pressure, the pressure gauge 40 detects a pressure drop and closes the discharge valve 34. In a preferred embodiment, the intelligent waste anesthetic gas collection unit 30 is powered by a DC low voltage power supply 6 to minimize the risk of fire and explosion.

  Preferably, the exhaust valve 34 comprises a normally open valve, and if a failure occurs, the exhaust valve 34 will open and fail (fail open) and the system will be substantially prior art continuous flow air dilution collection system. To return to. Furthermore, a means for preventing abnormal positive pressure or negative pressure from being transmitted to the anesthesia apparatus 12 is provided in the waste anesthetic gas collection unit 30 to ensure patient safety. Although unlikely to occur, if the discharge valve 34 leaks or sticks in the open position lowers the pressure in the chamber 32 well below atmospheric pressure, the mechanical vacuum breaker 7 is in the chamber 32 and is pulled open to the pressure Is restored to atmospheric pressure. Similarly, when the pressure in chamber 32 rises significantly above atmospheric pressure, mechanical relief valve 8 opens and releases excessive pressure to the atmosphere. The waste anesthetic gas collection unit 30 is preferably manufactured from materials that meet safety standards for use in high oxygen environments.

  Referring to FIGS. 3 and 4, the power source 6 is preferably wired in series with the switch contact 5 of the pressure gauge 40 and the solenoid 4 of the discharge valve 34. The attenuation capacitor 9 may be wired in parallel with the discharge valve solenoid 4 in some cases. As shown in FIG. 3, when the pressure in the chamber 32 is almost atmospheric pressure, the contact 5 of the pressure gauge 40 is closed, a current flows between the power source 6 and the solenoid 4, the solenoid 4 is energized, and the discharge valve 34 is turned on. close. As shown in FIG. 4, when the pressure in the chamber 32 becomes slightly higher than the atmospheric pressure, the contact 5 of the pressure gauge 40 is opened, so that the solenoid 4 is turned off and the discharge valve 34 is opened. The circuits shown in FIGS. 3 and 4 have the simplest configuration, but other more complicated circuits can be used. For example, the pressure gauge 40, the exhaust valve 34, and the circuitry between them are selected and configured to have a proportional response to pressure fluctuations, so that the valve 34 opens slightly for small pressure increases and for large pressure increases. Open it wide. Alternatively, for example, an appropriate means for detecting exhalation other than the pressure increase, such as halocarbon, humidity, and flow rate, may be used. The selection and configuration of pressure gauges, power supplies, and electrically actuated valves and the configuration of the basic electrical circuit are all well known in the art, so further discussion on this point will not be given here.

  In FIG. 3, an electrical circuit for coupling the pressure gauge 40 and the discharge valve 34 is shown, but alternatively, the pressure gauge 40 may be pneumatically or mechanically connected to the discharge valve 34 to control the discharge valve 34. It may be connected. Since the selection and configuration of mechanical pressure control actuators, mechanical drive valves, pneumatic control circuits and pneumatic drive valves are well known in the art, further discussion on this point will not be given here.

  In an alternative embodiment, shown in FIG. 5, the intelligent waste anesthesia gas collection unit 30 may be incorporated into the improved anesthetic device 50 instead of being incorporated into the medical facility waste anesthesia gas collection manifold 16. Thus, the improved anesthesia device 50 includes a prior art anesthesia device 12 and an intelligent waste anesthesia gas collection unit 30 according to the embodiments of the invention described herein. The improved anesthetic device 50 is detachably coupled to a standard waste anesthetic gas connector 18 of 19 mm, 30 mm or similar. A medical facility having a waste anesthesia gas regeneration system including an improved anesthesia apparatus 50 in all anesthesia centers 15 functions in the same manner as the waste anesthesia gas regeneration system 11 of FIG.

  FIG. 6 illustrates an alternative embodiment in which the collection units 30A, 30B, 30C are separated from the collection manifold 16 and the anesthetic devices 12A, 12B, 12C and are distinguished. In this embodiment, collection units 30A, 30B, 30C are each detachably connected to manifold 16 with a first standard (eg, 19 mm or 30 mm) waste anesthetic gas connector 18A, 18B, 18C. Each anesthesia apparatus 12A, 12B, 12C is detachably connected to the second standard waste anesthetic gas connectors 19A, 19B, 19C in order. Thus, an existing waste anesthetic gas collection system can be upgraded to a small flow regeneration system according to the present invention without the need to improve the collection manifold 16 or the anesthetic devices 12A, 12B, 12C.

  FIG. 7 illustrates a preferred embodiment of the process 1 according to the present invention for use in a hospital, surgical facility or other medical facility 110. The waste anesthetic gas is collected and passes through the valve 112 of the facility 110 and reaches the waste gas passage 39. The flow path 27 for supplying oxygen to the medical facility 110 preferably includes a valve 114 to which a downstream oxygen supply line in the medical facility 110 is fluidly connected. The liquid oxygen source is shown conceptually as a tank 120 and is preferably near the medical facility 110. At present, in hospitals and other medical facilities 110, liquid oxygen is passed through the heat exchanger 122 from the liquid oxygen temperature (about −193 ° C.) to room temperature (about 25 ° C.) before reaching the facility 110 through the flow path 27. ° C). Typically, liquid oxygen is heated using a heat exchanger 122 located near each tank 120, and the heat exchanger 120 exposes the liquid oxygen to ambient temperature. The heated liquid oxygen is then sent to a supply line (not shown) that distributes it to a location for use by a patient in the medical facility 110 by way of a flow path 27 and a valve 114.

  As shown in FIG. 7, in one embodiment of the present invention, the cryogenic trap / divider 25 includes a housing 130 containing a cooling coil 36 and functions as a heat exchanger. The interior of the cooling coil 36 is fluidly isolated from the rest of the housing 130, but the two interiors are thermally / thermally coupled. The cold trap / shunt 25 facilitates heat exchange from waste anesthetic gas in the housing 130 to liquid oxygen in the cooling coil 36. Waste anesthetic gas is supplied from the facility 110 through the flow path 39, and liquid oxygen is supplied from the liquid oxygen source 120 through the flow path 21. The housing 130 is preferably a double wall structure and is better insulated from the atmosphere, thus facilitating heat exchange only between the waste anesthetic gas and liquid oxygen.

  The liquid oxygen supply channel 21 is preferably fluidly connected to an inlet 47 of the condensing coil 36 by an automatic temperature control valve 33. The outlet 48 of the cooling coil is preferably fluidly connected to the oxygen supply channel 27 to the medical facility 110 by a channel 126. The existing heat exchanger 122 used to warm liquid oxygen is used when the cold trap / divider 25 is operated in a thawing cycle, as described below, or when the cold trap / divider 25 is maintained or repaired. When not in operation, the liquid oxygen tank 120 and the oxygen flow path 27 are used to warm oxygen when the oxygen demand of the medical facility is greater than that of the cold trap / divider 25. Preferably, it is left in a position to be fluidly connected in parallel with the cold trap / divider 25.

  The waste anesthetic gas channel 39 and the shutoff valve 112 are fluidly connected to a collection channel (not shown) of the medical facility 110. Preferably, the waste anesthetic gas flow path 39 is selectively fluidly connected to the inlet 31 or the air outlet 46 of the housing 130 by the bypass three-way valve 29. During normal operation, the flow path 39 is directed only to the inlet 31 of the housing 130 by the bypass three-way valve 29. The waste anesthetic gas flows through the housing 130 of the cold trap / divider 25 toward the exhaust fitting 37, during which time gas components are removed by condensation (evaporation) on the cooling coil 36, and the waste anesthetic gas is removed from the fitting 37. It flows out to the atmosphere via the discharge port 46. The waste anesthetic gas flow path 39 is preferably only aligned directly with the air outlet 46, bypassing the cold trap / shunt 25, when it is desired not to use system maintenance, repair or regeneration systems.

  Waste anesthetic gas (generally containing nitrogen, oxygen, nitrous oxide, water vapor and fluoroether) typically enters through flow path 39 at about 20-30 ° C. and a relative humidity in the range of 10-60 percent. . Waste anesthetic gas may also contain traces of lubricating oil vapor from a vacuum pump (not shown). Liquid oxygen (approximately −193 ° C.) flows into the cold trap / divider 25 at the inlet 47 to the cooling coil 36, while waste anesthetic gas (approximately 20-30 ° C.) flows into the cryogenic trap / divider 25 at the inlet fitting 31. The case 130 is entered. This counter-flow heat exchange arrangement creates a temperature gradient with the top of the cold trap / shunt 25 at the highest temperature and the bottom of the cold trap / shunt 25 at the lowest temperature. The upper region 60 of the cooling coil 36 of the cold trap / shunt 25 cools the waste anesthetic gas from about 20 ° C. to about −5 ° C. and extracts water vapor as frost on the cooling coil 36. The upper middle region 62 of the cooling coil 36 then cools the waste anesthetic gas and extracts sevoflurane onto the cooling coil 36 by condensation / evaporation at about −60 ° C. Next, the lower middle region 63 extracts nitrous oxide by condensation / evaporation at about -90 ° C, and finally the lower region 64 of the cooling coil 36 condenses / between -100 ° C and -110 ° C. Isoflurane and desflurane are extracted on the cooling coil 36 by vapor deposition. Direct condensation / deposition of the anesthetic component onto the cooling coil 36 typically occurs only at low temperatures and low pressures. For example, nitrous oxide condenses / deposits at temperatures and pressures below the triple point of -90 ° C and 880 kPa (0.88 bar). Alternatively, one or more anesthetic components may be liquefied on the cooling coil 36 in each temperature region 62, 63, 64 depending on individual physical characteristics, solidified and condensed.

  The remainder of the waste gas (mainly nitrogen and oxygen at about −110 ° C.) is then released into the atmosphere via flow path 46 or further processed, for example, using existing catalyst technology. Liquid oxygen flows into the cold trap / divider 25 at about −193 ° C. and exits the cold trap / divider 25 at about 0 ° C. The oxygen is further warmed in subsequent processing, or mixed with the hotter oxygen effluent from heat exchanger 122 to room temperature or other temperature suitable for use in a medical facility.

  The cold trap / divider 25 undergoes a thawing process periodically. During the thawing cycle, the cold trap / shunt 25 is slowly warmed to about 0 ° C. to defrost the cooling coil 36. Heating is performed by reducing or tightening the flow rate of liquid oxygen flowing through the cooling coil 36 by the automatic temperature control valve 33, and the low temperature trap / divider 25 is heated to room temperature by heat transfer with its surroundings. In an alternative embodiment, warm oxygen from heat exchanger 122 is flowed through cooling coil 36 by an open valve 59 to increase the thawing rate. Furthermore, in the third embodiment, another fluid (not shown) flows through the cooling coil 36 to perform controlled thawing.

  The bottom end 57 of the housing 130 has a funnel shape and acts as a hopper. The lowermost part is preferably drained to a four-way switching valve 58, which is in fluid communication with the three drain tanks 23, 24A, 24B in sequence. At sufficiently high pressure (ie, typically above atmospheric pressure), the coagulated anesthetic component melts as a liquid to be removed. Therefore, when the temperature is raised above -100 ° C, desflurane (melting point is about -108 ° C) and isoflurane (melting point is about -103 ° C) melt from the lower region 64 of the cold trap / shunt 25. , Gather in hopper 57. The four-way switching valve 58 is adjusted simultaneously so that liquid desflurane and isoflurane flow into the low melting point collection tank 24B by gravity. Alternatively, desflurane or isoflurane may be collected in tank 24A along with sevoflurane. While liquid desflurane and isoflurane are preferably collected in the same tank 24B, two separate collection tanks (not shown) may be used, one for each component.

  When the cold trap / shunt 25 is warmed above -90 ° C, the trapped nitrous oxide (melting point is about -90 ° C) melts from the low mid region 63 of the cold trap / shunt 25, Gather in hopper 57. The four-way switching valve 58 is adjusted at the same time so that liquid nitrous oxide flows into the middle melting point collection tank 24A by gravity. Alternatively, nitrous oxide may be collected in tank 24B along with desflurane and / or isoflurane, or a separate tank (not shown) may be used to collect nitrous oxide. When the temperature further increases, the four-way switching valve 58 is positioned so that the hopper 57 is aligned with the medium melting point collection tank 24A. When the temperature exceeds about −65 ° C., sevoflurane (melting point is about −67 ° C.) melts from the upper region 62 of the cooling coil 36 of the cold trap / shunt 25, collects in the hopper 57, and gravity enters the tank 24A. leak. Similarly, when the cold trap / divider 25 is warmed above the freezing point, water vapor frost melts from the upper region 60 and is directed into the high melting point collection tank 23 by the four-way switching valve 58. Vessels 24A, 24B are cooled and / or pressurized to maintain the collected fluoroether at a low vapor pressure to minimize evaporation loss. The containers 23, 24A, 24B may be of any suitable strength and capacity, for example, drums.

  In this way, the fluoroether is removed from the waste anesthetic gas and recovered individually by selective thawing of the deposited frost, so that it is fractionated by condensation / deposition and / or condensation / solidification. This regeneration method and system can also be used to remove other suitable gas components from waste anesthetic gas in addition to fluoroethers. Furthermore, in the present embodiment, it is described that the anesthetic component is fractionated by using three general melting point ranges. However, a larger number of melting point ranges or selectively narrowed melting point ranges are used. It can also be used appropriately.

  In a large hospital 110 having 20-30 operating rooms, the mass flow rate of waste anesthetic gas via channel 39 is 500-1000 l / min (14-35 scf / min) at pressures below 13.790 kPa (2 psig). Range. The oxygen gas inflow through the channel 21 to the same large hospital 110 at a temperature of approximately −150 ° C. averages 1000 to 2000 l / min (60-100 scf / min) at a pressure of about 344.738 kPa (50 psig). It is. Based on these flow rates, the cold trap / divider 25 has the capacity to capture 8 liters (10 kg) of frozen halocarbon gas and 20 liters (20 kg) of frozen water before a thawing cycle is required. It is preferable to be configured and arranged as described above. Alternatively, the waste gas system may be operated at a high pressure, for example up to about 50 psig, for increased efficiency, although condensation / deposition of anesthetic components would probably not be possible at this high pressure.

  Since the oxygen requirement at the facility 110 changes daily, the regeneration system 1 according to the preferred embodiment of the present invention includes an automatic temperature control bypass valve 59 in conjunction with the existing heat exchanger 122 and the cold trap / divider 25. Used to maintain the optimum oxygen supply temperature in the flow path 27 to the facility 110. The control system (not shown) includes a flow measurement device, a temperature measurement device, and / or a pressure measurement device (not shown), and is used to automatically adjust the settings of the automatic temperature control valves 33 and 59. The control system also includes a circuit for controlling the thawing cycle, and further appropriately controls the bypass valve 59 and the four-way switching valve 58. The design and configuration of selected measurement devices and control systems are well known in the art and will not be described further here. U.S. Patent No. 6,134,914 to Eschway et al. And U.S. Patent No. 6,729,329 to Berry are incorporated herein by reference.

  In the regeneration system 1 described above, only three additional components are required to be implemented in most medical facilities 110: (1) a cold trap / divert flow located and connected near the liquid oxygen source 120 25, (2) piping for supplying waste anesthetic gas to the cold trap / divider 25, and (3) drain tanks 23, 24A, 24B for collecting water and fractionated liquid halocarbons from the regeneration system 1. is there. In addition to liquid oxygen, other commonly available liquefied gases such as liquid nitrogen can also be used as a cooling source. The piping 39 that supplies waste anesthetic gas to the system 1 may have a relatively low pressure design, although the oxygen content of this stream may be as high as 40-50 percent. However, the high percentage of oxygen in the waste gas passage 39 requires attention to the installation of an oxygen clean (no fuel or pyrophoric material). All oxygen pathways are preferably completely grease free and are oxygen safe according to National Fire Protection Association Standard 99 (NFPA 99). The oxygen path through the heat exchanger 122 must also be a file safe design that allows total oxygen flow to the facility 110. Thus, in the preferred embodiment, oxygen from the tank 120 flows through the heat exchanger 122 to the flow path 27 and the facility 110 during a loss of power, while the automatic temperature control bypass valve 33 is closed. To prevent oxygen from flowing through the cold trap / divider 25.

  FIG. 8 illustrates an alternative embodiment of the present invention. The regeneration system 2 is basically the same as the regeneration system 1 of FIG. 7 except that it includes two cryogenic trap / dividers 25A, 25B arranged in parallel. When the first cold trap / shunt 25A is in a thawing cycle, the second cold trap / shunt 25B is operated in a cold trap mode and vice versa. This configuration enables continuous treatment of waste anesthetic gas. As a variation of this alternative embodiment, a third cold trap / shunt (not shown) may be added in parallel for redundancy.

  As shown in FIG. 8, the cold trap / dividers 25A and 25B have dedicated automatic temperature control valves 33A and 33B, respectively. The cold trap / dividers 25A, 25B also each have a combined waste gas supply valve 82A, 82B that operates in conjunction with the waste gas bypass valve 80 to allow the waste anesthetic gas flow to be operated in a capture cycle. / Send to shunt 25A, 25B. If desired, the cold trap / dividers 25A, 25B may also have waste gas vent valves 86A, 86B, respectively. Further, the drain valves 84A, 84B cooperate with the four-way switching valve 58 to drain liquid from the cold trap / dividers 25A, 25B operating in the thawing mode. The operation of the regeneration system 2 is preferably adjusted by a control system (not shown) including valves 33A, 33B, 82A, 82B, 84A, 84B, 86A, 86B, 58, 59. The design and configuration of the control system is well known in the art and will not be described further here.

  FIG. 9 illustrates a third embodiment of the present invention. At sufficiently low pressure (ie, typically below atmospheric pressure), one or more coagulated anesthetic components may sublime directly into the gas phase. Alternatively, one or more coagulated anesthetic components may evaporate during the thawing cycle, depending on the operating temperature and pressure of the cold trap / shunt 25. The regeneration system 3 is basically the same as the regeneration system 1 of FIG. 7 except that it is arranged and designed to recapture the anesthetic gas captured from the waste anesthetic gas stream and sublimated or evaporated during the thawing cycle. is there.

  As shown in FIG. 9, the regeneration system 3 includes a gaseous anesthetic collection tank 24C, a three-way collection valve 56, an optional vacuum pump 92 and an optional nitrogen or other gas source 89 with a shut-off valve 90, Includes additional equipment. The collection valve 56, the three-way switching valve 29 and the nitrogen shutoff valve 90 (if any) are preferably controlled by the control system (not shown) described above for use in the first embodiment of FIG. During the acquisition mode of operation, the three-way collection valve 56 is positioned so that the outlet fitting 37 is in fluid communication with the atmospheric discharge vent 46. Waste anesthetic gas enters the cold trap / shunt 25 through the inlet 31 and passes through the cooling coil 36 to capture water vapor, nitrous oxide, fluoroethers and other volatile halocarbons, It flows to the atmosphere through the nitrogen oxide collection valve 56 and the vent channel 46. Since fluoroethers and other halocarbon anesthetics are typically denser than either nitrogen or oxygen, the anesthetic gas that they are sublimated is whatever gas is present in the cold trap / shunt 25 (mostly nitrogen and oxygen). Collects below (oxygen). Thus, during the thawing cycle, these sublimated anesthetic gases collect at the bottom of the housing 130 directly above the liquid. The collection valve 56 is aligned so that the outlet fitting 37 is fluidly coupled to the gaseous anesthetic collection tank 24C. The solid anesthetic component that melts as a liquid rather than sublimates as a vapor is collected via the hopper 57, switching valve 58 and collection tanks 24A, 24B as disclosed above.

  Sublimated anesthetic gas is regenerated in one of many ways. In the first method, the sublimation anesthetic gas disposed immediately above the liquid level at the bottom of the housing 130 is moved using a nitrogen blanket and collected in the tank 24C. Nitrogen gas or other suitable blanket gas can flow through the nitrogen shut-off valve 90, through the inlet 31 and to the top of the cold trap / shunt 25. The three-way switching valve 29 closes to isolate the housing 130 from the vent 46 and waste anesthetic gas entering the facility 110. As nitrogen gas flows into the top of the cold trap / divider 25, a dense anesthetic gas flows through the outlet fitting 37, out of the cold trap / divider 25, and into the collection tank 24C. The nitrogen shutoff valve 90 is closed when all of the sublimation anesthetic gas has been removed from the cold trap / shunt 25. Residual nitrogen gas is swept away from the cold trap / divider 25 through outlet 37, valve 56 and vent 46.

  In the second method, the sublimation anesthetic gas arranged immediately above the liquid level at the bottom of the housing 130 can be sucked from the cold trap / divider 25 using the vacuum pump 92 and collected in the tank 24C. Again, the three-way switching valve 29 closes to isolate the housing 130 from the vent 46 and waste anesthetic gas entering from the facility 110. The vacuum pump 92 draws the sublimation anesthetic gas from the bottom of the housing 130 by suction, and sends it through the outlet 37 into the collection tank 24C. Once all the anesthetic gas has been withdrawn from the cold trap / divider 25, operation of the vacuum pump 92 ends and the position of the switching valve 56 is reset to prevent flow to the tank 24C.

  The sublimation anesthetic gas may be mixed with other gases in the cold trap / shunt 25 during the thawing cycle, thereby rendering the aforementioned regeneration method ineffective. In such a situation, nitrous oxide is separated from other gases using another method such as a pressure swing adsorption method or a membrane separation method. Various gas-gas separation techniques are well known in the prior art and will not be described further here. It is preferred that the collected anesthetic gas be processed for reuse by any regeneration method.

  In another embodiment of the present invention, the gaseous anesthetic collection means of the regeneration system 3 (FIG. 9) is incorporated into a plurality of cryogenic traps / shunts 25A, 25B of the regeneration system 2 (FIG. 8).

  FIG. 10 illustrates a preferred embodiment of a high flow waste anesthetic gas collection and regeneration system 200 having a compressor having at least one stage that raises the pressure of the waste anesthetic gas prior to anesthetic regeneration by condensation. The regeneration system 200 is similar to the previously described prior art waste anesthetic gas regeneration system 10 of FIG. 1 except that it includes one or more compression stages with an expansion valve 43 and a compressor 42. The compressor 42 is preferably disposed between the waste anesthetic gas collection units 15A, 15B, 15C and the condenser 22. The expansion valve 43 is preferably disposed between the capacitor 22 and the receiver container 45.

  As shown in FIG. 10, excess anesthetic gas, patient exhaled air and air are collected in masks 14A, 14B, 14C by anesthesia devices 12A, 12B, 12C and discharged to a common collection manifold 16. The waste anesthetic gas collection manifold 16 is typically tightly plumbed to the medical facility, and the anesthetic devices 12A, 12B, 12C are standard waste anesthetic gas connectors 18A, 18B, 18C, eg, 19 mm or 30 mm anesthesia connectors, Removably connected to the collection manifold 16. The waste anesthetic gas collection manifold 16 is operated with a slight vacuum generated by the compressor 42, for example 5 cm. From the collection manifold 16, the collected waste anesthetic gas is sent through a check valve 35 to the first stage of a single-stage or multi-stage compressor 42.

  In a preferred embodiment, the compressor 42 compresses waste anesthetic gas from the collection units 15A, 15B, 15C to a pressure of up to 50 psig for subsequent processing in the condensation unit 22. It is assumed to be size. A pressure greater than 344.738 kPa (50 psig) is preferred in order to enjoy the associated advantages of improved separation efficiency and fractional extraction. Multi-stage compressors are used to avoid problems with high compression ratios such as high temperature emissions and increased mechanical failure. Multistage compressors are also more economical than single stage compressors because of the reduction in power costs associated with each compression stage having a small compression ratio. However, the compressor 42 in the system 200 requires only a single stage compression since a compression ratio not expected to be greater than 10: 1 is expected.

  Capacitor 22 preferably uses liquid oxygen, liquid nitrogen or similar refrigerants obtained from a common source of liquefied gas normally available in hospitals and other medical, dental or veterinary facilities. When the waste anesthetic gas is compressed above the gas supply pressure from the facility (eg, 344.738 kPa (50 psig)), a common refrigerant supply is contaminated with waste anesthesia if a leak occurs in the capacitor unit 22. There is a possibility. In an alternative preferred embodiment, the waste anesthetic gas stream is compressed to a pressure well above 34 psi 38 kPa (50 psig) and enjoys the benefits of improved separation efficiency and fractional extraction. However, compression above 344.738 kPa (50 psig) requires liquid oxygen, to avoid the risk of contaminating the common gas supply of the medical facility with waste anesthesia if a leak occurs in the capacitor unit 22 Liquid nitrogen or similar refrigerant may be supplied separately.

  After compression, waste anesthetic gas flows through a collection or receiver container 26A, which removes the condensed liquid for compression and separates it from the compressed waste anesthetic gas stream. Prior to condensation recovery of the anesthetic component, the water vapor in the gas stream is removed and liquid water is preferably prevented from freezing in the condenser 22. A preferred method for removing water vapor from a waste anesthetic gas stream is to use the first condenser stage 222A (FIG. 11), but other water removal such as drying, absorption, filtration, semi-permeation or hydrophobic membranes. Processing (not shown) may be used. These various gas drying methods may be used at any point before condensing the anesthetic gas, including before the compression stage.

  The compressed waste anesthetic gas stream is then cooled in a single-stage or multi-stage condenser 22, and the temperature of nitrous oxide and other anesthetic halocarbons condense as a liquid that vapor can be removed onto the condenser coil 236B (FIG. 11). Or the temperature is reduced to either frost that collects on the capacitor coil 136 (FIG. 12). The temperature and pressure at which the condensation process takes place governs whether the anesthetic gas component is condensed as a liquid that can be removed or deposited as frost.

  After the anesthetic component is removed through condensation, the remaining waste gas (mainly comprised of entrained air) is released to the atmosphere 46. Preferably, the compressed waste gas is first passed through the expansion valve 43 and the receiver container 45 before the atmospheric discharge 46. The expansion valve 43 depressurizes the compressed waste gas to atmospheric pressure, and further cools the compressed waste gas by the Joule-Thompson effect. Additional anesthetic components in the waste gas can be condensed by Joule Thompson adiabatic expansion. Such anesthetic condensate is collected in the receiver container 45 prior to the atmospheric discharge 46 of the waste gas. More preferably, however, the compressed waste gas is first squeezed by a small turbine 44 (FIG. 13) or similar device and receiver vessel 45 prior to atmospheric release 46 (FIG. 13) to recover the potential energy of the compressed waste gas. . The recovered energy is used to power the compressor 42 or meet other energy demands of the method and system. The anesthetic component condensed by the expansion of the waste gas of the turbine 44 is also collected in the receiver container 45 prior to the atmospheric discharge 46 of the waste gas.

  Further, heat integration of the cooled waste gas with the stream to be cooled prior to atmospheric release can reduce the cooling utility throughout the method and system. For example, compression of the waste anesthetic gas stream increases the temperature of the gas stream. A cooled waste gas stream that is vented to the atmosphere 46 can be used to cool the compressed waste anesthetic gas stream prior to condensation, reducing the overall refrigerant requirement in the heat exchanger / condenser 22.

  Berry discloses two low temperature methods for recovering volatile halocarbons from waste anesthetic gas. The first is US Pat. No. 6,729,329, incorporated herein by reference, which discloses the use of liquid oxygen to condense and recover anesthetic gas components. FIG. 11 schematically illustrates the system and method of US Pat. No. 6,729,329, modified to allow compressed waste anesthetic gas flow. Since the dew point temperature of a typical anesthetic-containing vapor stream increases with increasing pressure, this first recovery method is greatly and advantageously influenced by the increased pressure of the waste anesthetic gas stream.

  The capacitor unit 22 includes a first capacitor 222A and a second capacitor 222B. The liquid oxygen outlet line 221 from the supply tank 220 is fluidly connected to the capacitor coil 236B of the second container 222B. The outlet of the capacitor coil 236B is fluidly connected to the inlet of the coil 236A of the first container 222A through the flow path 225. The outlet of the coil 236A is fluidly connected to the valve 214 and a flow path (not shown) of a medical facility connected thereto through the flow path 227.

  The flow path 239 connects the waste anesthetic gas flow path from the medical facility receiver container 26A (FIGS. 10 and 13) to the inlet of the heat exchanger / condenser 222A. The temperature of the oxygen flowing through the inlet of the coil 236A is automatically controlled by the valve 233, and the temperature of the oxygen supply at the valve 214 is about room temperature, that is, about 25 ° C. Waste anesthetic gas flows through flow path 239 and into heat exchanger / condenser 222A at an elevated temperature for compression. The compressed waste anesthetic gas flows into the top or inlet of the heat exchanger / condenser 222A and flows down over the coil 236A where it exchanges heat with the liquid oxygen flowing oppositely through the coil 236A. The water vapor in the compressed waste anesthetic gas condenses into liquid water at a specific temperature (above 0 ° C.), the specific temperature depending on the pressure of the compressed waste anesthetic gas stream. Thereafter, the liquid water flows to the tank 23 by gravity for storage and removal.

  The cooled compressed gas near the bottom of vessel 222A is directed through channel 241 to the top or inlet of heat exchanger / condenser 222B where it is used at temperatures above 0 ° C. The cooled compressed gas used at the top of heat exchanger / condenser 222B flows past coil 236B where it exchanges heat with the liquid oxygen that flows oppositely through coil 236B. Oxygen from the channel 221 flows into the coil 236B at a temperature of about −150 ° C., and flows out from the coil 236B through the channel 225 at an elevated temperature. If necessary, an intermediate bypass valve 235 may be disposed in the flow path 221 so that the temperature of the flow path 225 at the inlet of the coil 236A can be approximately 0 ° C. The temperature of the compressed waste anesthetic gas from the flow path 241 is lowered while passing through the coil 236B, and the waste gas halocarbon is liquefied and discharged to the collection tank 24. The remainder of the compressed waste gas, i.e., the component that does not harm the environment, is released to the atmosphere through the flow path 46, or is squeezed by the expansion valve 43 (Fig. 10) to produce further anesthetic condensate, or the small turbine 44 ( In FIG. 13), the potential energy of the compressed gas is collected and subjected to further processing with existing catalyst technology (not shown).

  Secondly, the co-pending U.S. patent application, the title of the invention “Anesthetic Gas Reclaim System and Method”, is incorporated herein by reference, but uses the batch frost fractionation process. As disclosed, the temperature of the individual anesthetic gases is cooled to a temperature that is collected as frost on the cold surface of the cold trap / shunt. The cold trap / shunt is periodically circulated to the thawing stage, during which the cooling surface solidified with the frost gas components deposited from the passing waste anesthetic gas is slowly warmed and the captured components are sequentially Separate and collect. FIG. 12 schematically illustrates the system and method of both pending patent applications, modified for incoming compressed waste anesthetic gas flow. However, since the freezing point temperature of a typical anesthetic-containing vapor stream is kept relatively constant with respect to the fluctuating system pressure, this second system and method of waste anesthesia regeneration is based on the pressure of the waste anesthetic gas stream. Not significantly affected by the rise.

  As shown in FIG. 12, the condenser unit 22 including the cold trap / divider 125 includes a cooling coil 136 therein. The liquid oxygen outlet channel 121 from the supply tank 120 is fluidly connected to the condenser coil 136 of the cold trap / divider 125. The flow rate of oxygen at the inlet of the capacitor coil 136 is controlled automatically by a valve 133. The existing heat exchanger 122 is used to warm liquid oxygen, but is positioned to be fluidly connected between the liquid oxygen tank 120 and the oxygen flow path 127 in parallel with the cold trap / divider 125. Is preferred and warms the oxygen when the cold trap / divider 125 is inconsistent with the facility's oxygen requirements, is operating in a thawing cycle as described below, or is not operated for maintenance or repair, for example. To do. Valve 129 is normally closed when heat exchanger 122 is not in use. Oxygen from the channel 121 flows into the capacitor coil 136 at a temperature of about −150 ° C. and flows out of the coil 136 at about 0 ° C. The oxygen that is to be used in the medical facility is further warmed in subsequent processes or mixed with the warm oxygen effluent from the heat exchanger 122 to reach room temperature or a suitable temperature. The outlet of the coil 136 is fluidly connected to a valve 144 and a medical facility flow path (not shown) connected to the valve 144 via the flow path 127.

  The flow path 139 connects the waste anesthetic gas flow path from the medical facility receiver container 26A (FIGS. 10 and 13) to the inlet 131 of the heat exchanger / condenser 125. The waste anesthetic gas flows into the heat exchanger / condenser 125 via the flow path 139 at an elevated temperature due to compression. The compressed waste anesthetic gas enters at the top of the heat exchanger / condenser 125 or at the inlet 131 and passes through the coil 136 and exchanges heat with liquid oxygen that flows oppositely through the coil 136. Waste anesthetic gas flows out of heat exchanger / condenser 125 through fitting 137 and is purged to the atmosphere via flow path 46.

  The counter-flow heat exchanger arrangement results in a temperature gradient with the top of the heat exchanger / condenser 125 having the highest temperature and the bottom of the heat exchanger / condenser 125 having the lowest temperature. The upper region 160 of the cooling coil 136 of the heat exchanger / condenser 125 cools the compressed waste anesthetic gas to a temperature of about −5 ° C. and extracts water vapor as frost on the cooling coil 136. The upper middle region 162 of the cooling coil 136 then cools the compressed waste anesthetic gas to a temperature of approximately −60 ° C., condensing and solidifying the sevoflurane on the cooling coil 136. Next, the lower middle region 163 extracts nitrous oxide by condensation and solidification at a temperature of about −90 ° C., and finally the bottom region 164 of the cooling coil 136 has a minimum temperature (about −100 ° C. and −110 ° C. In the meantime, isoflurane and desflurane are extracted by condensation and solidification on the cooling coil 136. Alternatively, if the heat exchanger / condenser 125 is operated at a low pressure (ie, vacuum pressure), the anesthetic component condenses / deposits directly on the coil 136 without first becoming a liquid phase. The remainder of the compressed waste anesthetic gas, i.e., components that do not harm the environment, are released to the atmosphere through the flow path 46 or are squeezed by the expansion valve 43 (FIG. 10) to produce further anesthetic condensate, or the small turbine 44 (FIG. 13), the potential energy of the compressed gas is recovered or subjected to further processing with existing catalyst technology.

  The cold trap / shunt 125 is periodically circulated through the thawing process to defrost the cooling coil 136. The coil 136 is thawed by reducing or eliminating the flow rate of liquid oxygen flowing through the automatic temperature control valve 133. This allows the cold trap / shunt 125 to be warmed to room temperature through heat exchange with the surrounding environment. In an alternative embodiment, warmed oxygen from heat exchanger 122 is flowed partially or completely through cooling coil 136 by simultaneously opening valve 159 and closing valves 133 and 154. Furthermore, in the third embodiment, other fluids (not shown) can be flowed through the cooling coil 136 for controlled thawing.

  A funnel-shaped hopper 157 forms the lowest point of the heat exchanger / condenser 125 and preferably drains fluid in the direction of the four-way switching valve 158, which in turn includes the anesthesia collection tanks 24A, 24B and water. Fluidly coupled to the collection tank 23. When the temperature of the cooling coil 136 rises to above about −100 ° C. during the thawing stage, desflurane (melting point at atmospheric pressure is about −108 ° C.) and isoflurane (melting point at atmospheric pressure is about −103 ° C.) are cold traps. From the bottom region 164 of the flow divider 125 and collect in the hopper 157. The switching valve 158 is adjusted simultaneously so that liquid desflurane and isoflurane are fed by gravity into one of the collection tanks 24A, 24B. As the cold trap / shunt continues to warm up to above −90 ° C., the trapped nitrous oxide melts from the low mid region 163 of the cold trap / shunt 125 and collects in the hopper 157. The switching valve 158 is adjusted at the same time so that liquid nitrous oxide is gravity fed into one of the collection tanks 24A, 24B. When the temperature is raised to above −65 ° C., sevoflurane (melting point at atmospheric pressure is about −67 ° C.) melts from the upper middle region 162 of the cooling coil 136 and collects in the hopper 157. The switching valve 158 is adjusted at the same time so that liquid sevoflurane is fed by gravity into one of the collection tanks 24A, 24B. Similarly, if the cold trap / divider 125 continues to warm, the water vapor frost melts from the upper region 160 above 0 ° C. and is flowed to the water collection tank 23 by the switching valve 158. By this method, the fluoroether is removed from the waste anesthetic gas and fractionated.

  FIG. 13 illustrates a low flow waste anesthetic gas collection and regeneration system 500 according to an alternative preferred embodiment of the present invention for use in a hospital, surgery, dentistry, veterinary or other medical facility. Regeneration system 500 is similar to that described above except that expansion valve 43 is replaced with turbine 44 and includes intelligent waste anesthesia gas collection units 30A, 30B, 30C located at or near each anesthesia site 15A, 15B, 15C of the medical facility. This is the same as the reproduction system 200 of FIG. As disclosed in co-pending U.S. patent application 11 / 266,966, intelligent waste anesthesia gas collection units 30A, 30B, 30C are connected to a collection manifold near standard waste anesthesia gas connectors 18A, 18B, 18C. Preferably, each of the 16 legs is fluidly coupled. Each intelligent waste anesthesia gas collection unit 30A, 30B, 30C has a collection chamber 32A, 32B, 32C, a discharge valve 34A that selectively shuts off the intake side of the collection manifold 16 at the respective anesthesia site when no waste anesthetic gas is generated. , 34B, 34C, and the associated pressure gauges 40A, 40B, 40C, circuits, controls or mechanisms for operating the discharge valves 34A, 34B, 34C. The collection chambers 32A, 32B, 32C are rigid, flexible (such as a telescopic bag) or a combination thereof.

  Referring to FIG. 13, waste anesthetic gas flows from anesthesia devices 12A, 12B, 12C through chambers 32A, 32B, 32C through 19 mm, 30 mm or similar standard waste anesthetic gas connectors 18A, 18B, 18C. Highly sensitive pressure gauges 40A, 40B, 40C are electrically coupled within solenoid chambers 32A, 32B, 32C to solenoid operated exhaust valves 34A, 34B, 34C located on the exhaust side of collection chambers 32A, 32B, 32C. The The pressure measured by the pressure gauges 40A, 40B, and 40C is the difference between the pressure in the collection chambers 32A, 32B, and 32C and the outside (atmosphere) pressure. When the pressure in the collection chambers 32A, 32B, and 32C becomes slightly higher than the atmospheric pressure, the pressure gauges 40A, 40B, and 40C detect the increased pressure, and the discharge valves 34A, 34B, and 34C are opened by the control circuit. Opening the drain valves 34A, 34B, 34C fluidly connects the collection chambers 32A, 32B, 32C with the vacuum source of the collection manifold 16, resulting in a rapid decrease in pressure in the collection chambers 32A, 32B, 32C. When the pressure in the collection chamber approaches atmospheric pressure, the pressure gauges 40A, 40B, 40C detect a pressure drop and close the exhaust valves 34A, 34B, 34C.

  The waste anesthetic gas collection manifold 16 is operated with a slight vacuum generated by the compressor 42, for example 5 cm. Therefore, isolating from the atmosphere entrained with the collection manifold 16 while no waste anesthetic gas is being produced reduces the average anesthetic gas collection flow by approximately 90 percent, and thus the compressor 42, heat exchanger / condenser 22, piping. And reducing the required maximum capacity of other accompanying machinery and equipment. In a large hospital with 20-30 operating rooms, the waste anesthetic gas flow rate of 500-1000 l / min in the prior art regeneration system 10 of FIG. 1 is reduced to 50-100 l / min in the regeneration system 500 of FIG. It is guessed. In addition, the low flow collection system provides a more efficient means of recovering waste anesthetic gas by condensation, since the small volume of gas that must be cooled to the condensation temperature of the respective anesthetic gas.

  From the vacuum manifold 16, the collected waste gas stream is routed through a check valve 35 to a compressor 42. The compressor 42 has a single stage compression stage sized to increase the waste anesthetic gas from the collection units 30A, 30B, 30C to a pressure above atmospheric pressure for subsequent treatment in the condenser unit 22. After compression, waste anesthetic gas flows through a collection or receiver container 26A, which removes the condensed liquid for compression and separates it from the compressed waste anesthetic gas stream. The compressed waste anesthetic gas stream is then cooled in a multi-stage condenser 22 and the temperature of nitrous oxide and other anesthetic halocarbons is lowered to a temperature at which the vapor condenses as a liquid that can be removed onto the condenser coil 236B (FIG. 11). (See the disclosure regarding FIG. 11). Alternatively, the vapor can be condensed and collected as frost on a condenser coil 136 (FIG. 12) using a single stage cold trap / shunt 125 (FIG. 12) (see disclosure regarding FIG. 12). Depending on the temperature and pressure at which the condensation process is performed, it is determined whether the anesthetic gas component is condensed as moisture that can be removed or condensed as frost. The liquid anesthetic condensate is collected in the collection containers 24A and 24B, and the liquid moisture condensate is collected in the collection container 23.

  As already disclosed, it is preferable to squeeze the compressed waste gas before it is released to the atmosphere 46 with a small turbine 44 or similar device to recover the potential energy of the compressed waste gas. The recovered energy can then be used to power the compressor 42 or meet other energy needs of the method and system. By reducing the pressure of the compressed anesthetic gas stream at the turbine 44, further condensation of the anesthetic component occurs. Accordingly, a receiver container 45 is installed to collect these anesthetic condensates prior to atmospheric discharge 46 of the remaining waste gas.

  A preferred embodiment of a self-contained waste anesthesia gas regeneration system is arranged and designed to operate with minimal dependence on medical facility utility equipment and replenishment. Unlike other systems that require liquid oxygen and / or liquid nitrogen supplied from a medical facility to condense the gaseous anesthetic component, the system disclosed herein is mechanical power or power for operation. Only need a supply of. Furthermore, the system simply requires venting to the atmosphere to exhaust waste gas without anesthetic components and does not require a large scale waste air treatment system. Thus, this preferred embodiment is relatively self-contained and can be easily accommodated in a clinic, veterinary clinic or dental clinic. (Relatively large, more standard waste anesthesia gas regeneration systems, such as those conventionally used in hospitals, would not be practical to install on them due to their overall size and cost. )

  FIG. 14 illustrates a preferred embodiment heat exchanger / condenser 222 of the present invention that cools and condenses anesthetic gas components from a waste anesthetic gas stream by countercurrent heat exchange with an intermediate heat transfer fluid. A heat transfer fluid, such as DuPont's Suva® 95 or similar cryogenic refrigerant, is sufficiently transferred before it is returned to the heat exchanger / condenser 222 using a conventional power or mechanical power cooling unit 270. Cooling. Using a separate cooling unit 270 to cool the heat transfer fluid or refrigerant eliminates the need for liquid nitrogen or liquid oxygen to be supplied by the medical facility. DuPont Suva® 95 is a preferred refrigerant. Because it is an industry standard used in medical refrigerators and other ultra-low temperature specifications (between −40 ° C. and −101 ° C.), with very low compressor discharge temperatures, higher system reliability and compressor performance This is because it has a long life and is environmentally friendly.

  As shown in FIG. 14, the heat transfer fluid flows through the coil 236 of the heat exchanger / condenser 222 and evaporates upon absorbing heat from the anesthetic gas component that condenses on the outer surface of the coil 236. The intermediate heat transfer fluid is then cooled in a conventional vapor compression process using one or more cooling stages. The saturated (or slightly superheated) heat transfer fluid is at least partially evaporated here and is compressed to high pressure by the compressor 272. Compression causes the heat transfer fluid to be superheated at the outlet of the compressor 272 (ie, higher than the fluid saturation temperature at the increased pressure). The superheated fluid is subsequently cooled and condensed in heat exchanger / condenser 274 using a suitable refrigerant, preferably air. The fluid condensed at the increased pressure is then throttled by the expansion valve 276 to a low pressure. At this point, the heat transfer fluid consisting primarily of liquid and low-grade vapor can once again absorb heat from the anesthetic gas component that condenses in the heat exchanger / condenser 222.

  As an alternative to conventional cooling systems, a cryogenic cooling unit (not shown) is used to cool the intermediate heat transfer fluid to a lower temperature (ie, well below -73 ° C.) than is achieved with conventional cooling systems. May be. To enable condensation with a very high vapor pressure gaseous anesthetic component (ie, an anesthetic with a freezing point below −73 ° C.), a heat transfer fluid cooled to a cryogenic temperature is used, as described above. Such anesthetic components are cooled and condensed. Since cryogenic cooling processes, such as simple Linde or Joule Thomson cycles, are well known in the prior art, no further explanation is given here.

  FIG. 15 illustrates a low flow waste anesthetic gas collection and regeneration system 300 for use in a clinic, dental clinic, small animal clinic or other medical facility, according to a preferred embodiment of the present invention. The regeneration system 300 includes the small turbine 344, one or more compression stages by the compressor 342, and the intelligent waste anesthesia gas collection unit 330 located at or near the medical facility anesthesia 315, as described above with respect to FIG. This is the same as the waste anesthetic gas regeneration system 10 of the prior art. The compressor 342 is preferably disposed between the intelligent waste anesthetic gas collection unit 330 and the condenser 322. The small turbine 344 is preferably disposed between the condenser 322 and the atmospheric vent 346.

  Intelligent waste anesthesia gas collection unit 330 is fluidly coupled to collection inlet 316 near standard waste anesthesia gas connector 318 as disclosed in co-pending US patent application 11 / 266,966. Is preferred. The intelligent gas collection unit 330 operates the collection chamber 332, a discharge valve 334 that selectively shuts off the intake side of the collection intake 316 at the corresponding anesthesia when no waste anesthetic gas is generated, and the discharge valve 334. The accompanying pressure gauge 340, circuit, control or mechanism. The collection chamber 332 is rigid, flexible (such as a telescopic bag) or a combination thereof.

  Referring to FIG. 15, the waste anesthetic gas flows from the anesthesia device 312 into the chamber 332 through a 19 mm, 30 mm or similar standard waste anesthetic gas connector 318. A sensitive pressure gauge 340 is electrically coupled within the chamber 332 to a solenoid operated exhaust valve 334 disposed on the exhaust side of the chamber 332. The pressure measured by the pressure gauge 340 is the difference between the pressure in the chamber 332 and the outside (atmosphere) pressure. When the pressure in the chamber 332 becomes slightly higher than the atmospheric pressure, the increased pressure is detected by the pressure gauge 340 and the discharge valve 334 is opened by the control circuit. Opening the exhaust valve 334 fluidly connects the chamber 332 with the vacuum source at the collection inlet 316, resulting in a rapid decrease in the chamber 332 pressure. As the chamber pressure approaches atmospheric pressure, the pressure gauge 340 detects a pressure drop and closes the exhaust valve 334.

  The waste anesthetic gas collection inlet 316 is operated with a slight vacuum generated by the compressor 342, for example 5 cm. If the compressor 342 is not used in the system 300, a vacuum pump (not shown) must be placed between the collection inlet 316 and the atmospheric vent 346 to generate a slight vacuum at the collection inlet 316. Isolating from the atmosphere entrained with the collection inlet 316 while no waste anesthetic gas is being generated reduces the average anesthetic gas collection flow by approximately 90 percent, and thus the compressor 342, heat exchanger / condenser 322, piping and The necessary maximum capacity of other accompanying mechanical equipment (not shown) is reduced. In a large hospital with 20-30 operating rooms, it is estimated that a waste anesthetic gas flow of 500-1000 l / min is expected using the prior art regeneration system 10 of FIG. In a small flow collection system, this anesthetic gas flow will be reduced to 50-100 l / min. The system 300 shown in FIG. 15 is for implementation in a small medical facility and is designed for anesthetic gas flow of 1 to 20 l / min. Nonetheless, the small flow collection system is a more efficient means of recovering waste anesthetic gas by condensation at any anesthetic gas flow rate, since the small volume of gas that must be cooled to the condensation temperature of each anesthetic gas. I will provide a.

  From the collection inlet 316, the collected waste gas stream is sent through the check valve 335 to the compressor unit 342. In a preferred embodiment, the compressor 342 is sized to compress the waste anesthetic gas from the collection unit 330 to a pressure above atmospheric for subsequent treatment with the condenser unit 322. A pressure exceeding 50 psig is preferred to benefit from the associated separation efficiency and improved fractional extraction. Multi-stage compressors are used to avoid problems with high compression ratios such as high temperature emissions and increased mechanical failure. As a result, compressor manufacturers recommend compression ratios not greater than 10: 1, especially in low temperature use. Multistage compressors are also more economical than single stage compressors because of the reduction in power costs associated with each compression stage having a small compression ratio. However, the compressor 342 in the system 300 requires only a single stage compression since a compression ratio not expected to be greater than 10: 1 is expected.

  After compression, waste anesthetic gas flows through a collection or receiver vessel 326 that removes the condensed liquid for compression and separates it from the compressed waste anesthetic gas stream. Prior to condensation recovery of the anesthetic component, the water vapor in the gas stream is removed to prevent the liquid water from freezing in the condenser 322. A preferred method for removing water vapor from a waste anesthetic gas stream is to use the first condenser stage 422A (FIG. 16), but other water removal such as drying, absorption, filtration, semi-permeation or hydrophobic membranes. Processing (not shown) may be used. These various gas drying methods may be used at any point before condensing the anesthetic gas, including before the compression stage.

  The compressed waste anesthetic gas stream is then cooled in a single or multi-stage condenser 322, and the temperature of nitrous oxide and other anesthetic halocarbons condenses as a liquid that can be removed by vapor onto the condenser coil 436B (FIG. 16). Or the temperature is reduced to either the temperature of frost on the capacitor coil 536 (FIG. 17). The temperature and pressure at which the condensation process takes place governs whether the anesthetic gas component is condensed as a liquid that can be removed or deposited as frost. For the system 300 shown in FIG. 15, a capacitor 322 of at least two stages 422A, 422B (FIG. 16) is preferred. The first stage 422A (FIG. 16) is used to remove water vapor from the waste anesthetic gas stream, while the next stage 422B (FIG. 16) is used to condense the anesthetic. Liquid anesthetic components (not fractionated) are collected in container 324, liquid water condensate is collected in container 323, and both containers are periodically drained.

  A dedicated heat transfer fluid flows through coils 436A, 436B, 536 (FIGS. 16 and 17) of condenser 322 and is used to cool and condense waste anesthetic gas components. A heat transfer fluid, such as DuPont Suva® 95 or similar cryogenic refrigerant, is sufficiently cooled using a conventional power cooling unit 370 before being returned to the heat exchanger / condenser 322. As described above and shown in FIG. 14, the intermediate heat transfer fluid is cooled by a conventional vapor compression process using one or more cooling stages. By using a separate cooling unit 370 to cool the heat transfer fluid or refrigerant, liquid nitrogen and / or liquid oxygen need not be supplied from the medical facility. However, liquid oxygen, liquid nitrogen or similar refrigerants obtained from the normal supply of liquefied gas normally available in hospitals and other medical, dental and veterinary facilities can be used in place of the dedicated heat transfer fluid. If the waste anesthetic gas is compressed above the facility gas supply pressure (eg, 50 psig), contamination with the common refrigerant supply waste anesthesia can occur if an internal leak occurs in the capacitor unit 322. . Therefore, when using liquid oxygen, liquid nitrogen, or similar refrigerants, a separate source is provided for waste anesthetic gas pressure exceeding 344.738 kPa (50 psig) and the common gas supply of the medical facility is used as waste anesthetic gas. The risk of contamination should be avoided.

  After the anesthetic component is removed by condensation, the remaining waste gas (consisting primarily of entrained air) may be released to the atmosphere 346. More preferably, however, the compressed waste gas is first throttled with a small turbine 344 or similar device prior to atmospheric release 346 to recover the potential energy of the compressed waste gas. The recovered energy is then used to power the compressor 342 or to supply other energy demands of the method or system. Additional anesthetic components in the waste gas may also condense due to expansion in the turbine 344. Such anesthetic condensate is collected in a receiver vessel 345 prior to an atmospheric discharge 346 of waste gas.

  Furthermore, the total cooling utility of the method and system can be reduced by thermally integrating the cooled waste gas with the stream to be cooled prior to venting to the atmosphere. For example, compression of the waste anesthetic gas stream increases the temperature of the gas stream. The cooled waste gas stream that is vented to the atmosphere 346 can be used to cool this compressed waste anesthetic gas stream before condensing, reducing the overall refrigerant requirements of the heat exchanger / condenser 322.

  Berry discloses two cryogenic methods for recovering volatile halocarbons from waste anesthetic gas. The first, and more preferred, is US Pat. No. 6,729,329, incorporated herein by reference, which uses liquid oxygen to condense an anesthetic gas component into a liquid condensate that can be recovered. It is disclosed. FIG. 16 schematically illustrates the system and method of US Pat. No. 6,729,329, incorporating an inflowing compressed waste anesthetic gas stream and supplying liquid oxygen to DuPont's Suva® 95 or similar cryogenic refrigerant. There have been modifications to replace it with a dedicated heat transfer fluid. Since the dew point temperature of a typical anesthetic-containing vapor stream increases with increasing pressure, this first method of recovery of waste anesthetic is greatly and advantageously influenced by the increased pressure of the incoming waste anesthetic gas stream.

  A capacitor unit 422 including a first capacitor 422A and a second capacitor unit 422A is provided. The outlet channel 421 for the cooled heat transfer fluid from the cooling unit 270 (FIG. 14) is fluidly connected to the capacitor coil 436B of the second container 422B. The outlet of the capacitor coil 436B is fluidly connected to the inlet of the coil 436A of the first container 422A via the flow path 425. The outlet of the coil 436A is fluidly connected to the inlet of the small cooling unit 270 (FIG. 14) via the flow path 427.

  The flow path 439 connects the waste anesthetic gas flow path from the medical facility receiver containers 326, 626 (FIGS. 15 and 18) to the heat exchanger / condenser 422. Waste anesthetic gas flows into heat exchanger / condenser 422 through channel 439 at an elevated temperature for compression. The compressed waste anesthetic gas flows into the top or inlet of the heat exchanger / condenser 422A, passes through coil 436A down, and exchanges heat with the heat transfer fluid flowing oppositely in coil 436A. Water vapor in the compressed waste anesthetic gas condenses into liquid water at a specific temperature (greater than 0 ° C.), and the specific temperature depends on the pressure of the compressed waste anesthetic gas stream. The liquid water then flows by gravity into tank 423, where it is stored and removed.

  The cooled compressed gas near the bottom of vessel 422A is directed through channel 441 to the top or inlet of heat exchanger / condenser 422B where it is at a temperature above 0 ° C. The cooled compressed gas that reaches the top of the heat exchanger / condenser 422B passes through the coil 436B and exchanges heat with the heat transfer fluid that flows oppositely in the coil 436B. The heat transfer fluid from the flow path 421 flows into the coil 436B at a temperature of about −90 ° C., and flows out of the coil 436B at a temperature elevated through the flow path 425. If necessary, an intermediate bypass valve 437 may be provided in the flow path 421, and the temperature of the flow path 425 at the inlet of the coil 436A may be about 0 ° C. The temperature of the compressed waste anesthetic gas from the flow path 441 is lowered while passing through the coil 436B, and the waste gas halocarbon is liquefied and discharged to the collection tank 424. It is preferable to squeeze the remainder of the compressed waste gas, that is, a component that does not harm the environment, using the small turbine 344 (FIG. 15), and recover the potential energy of the compressed gas. Alternatively, such compressed waste gas is released into the atmosphere via flow path 446, or throttling through expansion valve 643 (FIG. 18), or further processing by existing catalyst technology (not shown). You may attach.

  The second is a co-pending U.S. patent application, entitled “Anesthetic Gas Reclamation System and Method”, which is incorporated herein by reference, which application is for batch frost fractionation processes. The use is disclosed and the temperature of the individual anesthetic gases is cooled to a temperature that condenses and collects as frost on the cold surface of the cold trap / shunt. The cold trap / divider is periodically circulated to the thawing stage, during which the cooling surface solidified with vaporized frost gas components from the waste anesthetic gas that passes through is slowly heated to separate the captured components sequentially. And collect. FIG. 17 schematically illustrates the system and method of the above-mentioned patent application, both of which are ongoing, incorporating an incoming compressed waste anesthetic gas stream and dedicated liquid oxygen such as SUVA® 95 or similar cryogenic refrigerant. Modifications to replace heat transfer fluids have been made. However, since the freezing point temperature of a typical anesthetic-containing vapor stream remains relatively constant with respect to the fluctuating system pressure, this second waste anesthesia recovery method is less sensitive to the pressure increase of the waste anesthetic gas stream. Not greatly affected.

  As shown in FIG. 17, the cold trap / shunt or condenser unit 522 includes a cooling coil 536 therein. An outlet channel 521 for the cooled heat transfer fluid from the cooling unit 570 is in fluid connection with the condenser coil 536 of the cold trap / shunt 522. The flow rate of the cooled heat transfer fluid at the inlet of the coil 536 is controlled by the valve 533 in a temperature-controlled manner. The cooled heat transfer fluid from the flow path 521 flows into the coil 536 at a temperature of about −90 ° C. and flows out of the coil 536 at about 0 ° C. The outlet of the coil 536 is fluidly connected to the inlet of the small cooling unit 570 via the flow path 527.

  The flow path 539 connects the waste anesthetic gas flow path from the medical facility receiver containers 326, 626 (FIGS. 15 and 18) to the inlet 531 of the heat exchanger / condenser 522. Waste anesthetic gas flows into heat exchanger / condenser 522 through flow path 539 at an elevated temperature for compression. The compressed waste anesthetic gas flows into the top or inlet 531 of the heat exchanger / condenser 522, passes through the coil 536 below, and exchanges heat with the heat transfer fluid flowing oppositely in the coil 536. The waste gas flows out of the heat exchanger / condenser 522 through the fitting 537 and is discharged to the atmosphere through the flow path 546.

  This counter flow heat exchanger arrangement results in a temperature gradient where the top of the heat exchanger / condenser 522 is hottest and the bottom of the heat exchanger / condenser 522 is coldest. The upper region 560 of the cooling coil 536 of the heat exchanger / condenser 522 cools the compressed waste anesthetic gas to a temperature of about −5 ° C. and extracts water vapor as frost on the coil 536. The middle region 562, 563 of the cooling coil 536 then cools the compressed waste anesthetic gas to a temperature of about −60 ° C., condensing and solidifying the sevoflurane on the coil 536. Finally, the lower region 564 extracts nitrous oxide by condensation and solidification at a temperature of about -90 ° C. Alternatively, if the heat exchanger / condenser 522 is operated at a low pressure (ie, vacuum pressure), the anesthetic component may first condense / deposit directly on the coil 536 without going into a liquid phase. Further, if the waste anesthetic gas contains isoflurane (melting point about −103 ° C.) and / or desflurane (melting point about −108 ° C.), these anesthetic components condense and solidify on the lower region 564 of the coil 536. In addition, a heat transfer fluid or liquefied gas cooled to a cryogenic temperature such as liquid oxygen or liquid nitrogen may be required.

  It is preferable to squeeze the remainder of the compressed waste gas, that is, a component that does not harm the environment, using the small turbine 344 (FIG. 15), and recover the potential energy of the compressed gas. Alternatively, such compressed waste gas is released into the atmosphere via flow path 546, or throttling through expansion valve 643 (FIG. 18), or further processing by existing catalyst technology (not shown). You may attach.

  The cold trap / shunt 522 circulates the thawing process periodically to defrost the cooling coil 536. The coil 536 is thawed by reducing or eliminating the flow rate of the heat transfer fluid flowing therethrough by the automatic temperature control valve 533. This allows the cold trap / shunt 522 to be warmed to room temperature through heat exchange with the ambient environment at ambient temperature. In alternative embodiments, other fluids (not shown) may be flowed through the cooling coil 536 for controlled thawing.

  A funnel-shaped hopper 557 forms the lowest point of the heat exchanger / condenser 522 and preferably drains in the direction of the four-way switching valve 558, which in turn is an anesthetic collection tank 524A, 524B and a water collection tank. 523 and fluidly coupled. As the temperature of the cooling coil 536 rises to above about −90 ° C. during the thawing stage, nitrous oxide melts from the lower region 564 of the cold trap / shunt 522 and collects in the hopper 557. The switching valve 558 is simultaneously adjusted so that liquid nitrous oxide is gravity fed into one of the collection tanks 524A, 524B. When the temperature is raised to above −65 ° C., sevoflurane (melting point at atmospheric pressure is about −67 ° C.) melts from the middle regions 562 and 563 of the cooling coil 536 and collects in the hopper 557. The switching valve 558 is adjusted at the same time so that liquid sevoflurane is fed by gravity into the second collection tanks 524A, 524B. Similarly, if the cold trap / divider 522 continues to warm, the water vapor frost melts from the upper region 560 above 0 ° C. and is flowed to the water collection tank 523 by the switching valve 558. By this method, the fluoroether is removed from the waste anesthetic gas and fractionated.

FIG. 18 illustrates a waste anesthetic gas collection and regeneration system 600 according to a preferred embodiment of the present invention for use in a clinic, dental clinic, small animal clinic or other medical facility. The regeneration system 600 is similar to the waste anesthesia gas regeneration system 300 of FIG. 15 described above, and the system 600 is similar to the system 300 in operating power (not shown), the waste anesthesia gas source 615, and the atmospheric vent. Only 646 is required. However, the system 600 is further designed and arranged in a small, self-contained manner to facilitate its placement in a hospital room close to the anesthesia device 612. The system 600 is preferably a package unit 602 with a total volume of about 0.0283 m ³ (1 cubic foot). The system 600 includes a heat exchanger / shunt 622, which is an anesthetic gas from a waste anesthetic gas stream by countercurrent heat exchange with an intermediate heat transfer fluid cooled by a small cooling unit 670. Cool and condense components. Optionally, the system 600 may include a small compressor 642 and a receiver vessel 626 and / or an expansion valve 643 (or a small turbine 344 (FIG. 15)) and a receiver vessel 645. Further, the system 600 can include a low flow waste anesthetic gas collection unit 630.

  In a preferred embodiment as shown in FIG. 18, system 600 includes a compressor 642 and receiver container 626 in addition to expansion valve 643 and receiver container 645. Designed to handle anesthesia gas flow rates of 1-20 l / min, the waste anesthesia gas collection and regeneration system 600 is configured with an existing high flow waste anesthesia gas collection unit 615 via an attachable channel 606, more preferably Combined with a small flow waste anesthetic gas collection unit 630. The waste anesthetic gas inlet 616 is operated at a slight vacuum pressure generated by the compressor 642, for example 5 cm, and the compressor 642 is preferably located between the inlet 616 and the heat exchanger / condenser 622. From the collection inlet 616, the collected waste gas stream is routed through a check valve 635 to the compressor 642. The compressor 642 has a single stage compression stage sized to increase the pressure of the waste anesthetic gas from the collection units 615, 630 to a pressure above atmospheric for subsequent processing at the condenser unit 622.

  After compression, waste anesthetic gas flows through a collection or receiver vessel 626, which removes the condensed liquid for compression and separates it from the compressed waste anesthetic gas stream. The compressed waste anesthetic gas stream is then cooled in a multi-stage condenser 622, and nitrous oxide and other anesthetic halocarbons are lowered to a temperature that condenses on the condenser coil 436B (FIG. 16) as a liquid from which vapor can be removed (FIG. 16). 16). Alternatively, a single stage condenser (FIG. 17) can be used to condense and collect the vapor as frost on the condenser coil 536 (FIG. 17) (see disclosure regarding FIG. 17). The temperature and pressure at which the condensation process takes place governs whether it condenses as a liquid from which anesthetic gas components can be removed or deposits as frost. For the system 600 shown in FIG. 18, a capacitor 622 having at least two stages 422A, 422B (FIG. 16) is preferred. The first stage 422A (FIG. 16) is used to remove water vapor from the waste anesthetic gas stream and the second stage 422B (FIG. 16) is used to condense the anesthetic. Liquid anesthetic condensate (unfractionated) is collected in a small volume (ie 1 liter) container 624 and liquid water condensate is collected in a small volume (ie 1 liter) container 623, both containers being regularly The liquid is drained.

  A dedicated heat transfer fluid flows through the coils 436A, 436B, 536 (FIGS. 16, 17) of the condenser 622 and is used to cool and condense the anesthetic gas components. A heat transfer fluid, such as DuPont Suva® 95 or similar cryogenic refrigerant, is then cooled using a conventional power cooling unit 670 before being returned to the heat exchanger / condenser 622. . As described above and shown in FIG. 14, the intermediate heat transfer fluid is cooled by a conventional vapor compression process using one or more cooling stages. By using a separate cooling unit 670 to cool the heat transfer fluid or refrigerant, liquid nitrogen and / or liquid oxygen need not be supplied from the medical facility. However, liquid oxygen, liquid nitrogen or similar refrigerants obtained from the normal supply of liquefied gas normally available in hospitals and other medical, dental and veterinary facilities can be used in place of the dedicated heat transfer fluid.

  After the anesthetic component is removed by condensation, the remaining waste gas (consisting primarily of entrained air) preferably passes through expansion valve 643 and receiver vessel 645 prior to atmospheric release 646. The expansion valve 643 depressurizes the compressed waste gas to atmospheric pressure, and further cools the waste gas through the Joule-Thompson effect. Due to the adiabatic expansion of Joule Thomson, further anesthetic components remaining in the waste gas may condense. Such anesthetic condensate is collected in a receiver container 645 prior to atmospheric discharge 646 of the waste gas.

  The cooled waste gas that is vented to the atmosphere 646 is then preferably used to cool the compressed waste anesthetic gas stream in the flow path 639 that flows in the counterflow heat exchanger 680. This reduces the cooling requirement of the heat exchanger / condenser 622 and thus reduces the overall operating cost of the system 600. The waste gas throttled by the expansion valve 643 and heated by the heat exchanger 680 is discharged through the attachable flow path 637 to the existing air vent 646 of the medical facility.

  The abstract of this disclosure is written only to provide the United States Patent and Trademark Office and the public with a means to quickly determine the essence and gist of technical disclosure and to show only preferred embodiments. It does not suggest the essence of the present invention as a whole.

  Although several embodiments of the present invention have been illustrated in detail, the present invention is not limited to the illustrated embodiments. Those skilled in the art will recognize modifications and adaptations of the above-described embodiment. Such modifications and adaptations are within the spirit and scope of the invention as described herein.

FIG. 1 schematically illustrates a prior art high flow waste anesthesia gas collection and regeneration system that collects fluoroethers and other volatile anesthetic gas components before the waste gas stream is released to the atmosphere. Separate from. FIG. 2 schematically illustrates a preferred embodiment of a low flow waste anesthesia gas regeneration system according to the present invention, including an intelligent waste anesthesia gas collection unit that restricts air discharge to the combined vacuum system. FIG. 3 is a detailed conceptual diagram of the intelligent waste anesthesia gas collection unit of FIG. FIG. 4 is a detailed conceptual diagram of the intelligent waste anesthesia gas collection unit of FIG. It is operated like so. FIG. 5 schematically illustrates another embodiment of a low flow waste anesthetic gas regeneration system, where an intelligent waste anesthetic gas collection unit is combined with a prior art anesthetic device to form an improved anesthetic device. FIG. 6 schematically illustrates an alternative embodiment of a low flow waste anesthesia gas regeneration system useful for retrofitting existing systems, where the intelligent anesthesia gas collection unit is separated from the collection manifold and the anesthesia device. Are distinguished. FIG. 7 illustrates the process and system in a schematic diagram, in which waste anesthetic gas fluoroethers and other volatile halocarbon gas components are separated from the waste anesthetic gas using a source of liquid oxygen as a heat sink for the process. Subsequently, the resulting liquid halocarbon is fractionated by thawing and collecting sequentially. FIG. 8 illustrates in schematic diagram an alternative embodiment including two or more cryogenic traps / shunts in parallel. FIG. 9 schematically illustrates an alternative embodiment of the regeneration system of FIG. 7 and includes means for collecting captured components of waste anesthetic gas that has evaporated from the liquid phase or sublimated directly to the gas phase. FIG. 10 schematically illustrates a preferred embodiment according to the present invention of a high flow waste anesthesia gas regeneration system, including one or more high flow waste anesthetic gas collection units and a compressor comprising one or more compression stages. A single or multi-stage condenser / heat exchanger unit and an expansion valve for introducing additional anesthetic gas condensate. FIG. 11 illustrates the process and system in a schematic diagram, wherein a halocarbon gas component of a waste anesthetic gas is liquefied using a source of liquid oxygen in a medical facility and prior to release of the waste anesthetic gas to the atmosphere. Remove any gas components. FIG. 12 illustrates the process and system in a schematic diagram, in which waste anesthetic gas fluoroethers and other volatile halocarbon gas components are introduced into the atmosphere using a source of liquid oxygen as a heat sink for the process. Prior to release, it is separated from the waste anesthetic gas and subsequently fractionated by sequentially thawing and collecting the resulting liquid halocarbon. FIG. 13 schematically illustrates a preferred embodiment according to the present invention of a low flow waste anesthetic gas regeneration system, including one or more low flow waste anesthetic gas collection units and a compressor comprising one or more compression stages. A single or multi-stage condenser / heat exchanger unit and a small turbine that captures the potential energy of the compressed waste gas before being released into the atmosphere. FIG. 14 schematically illustrates a heat exchanger / condenser according to a preferred embodiment of the present invention, wherein anesthetic gas components from a waste anesthetic gas stream are counterflowed with an intermediate heat transfer fluid cooled by a small cooling unit. Heat exchange with chill to cool and condense. FIG. 15 schematically illustrates a preferred embodiment of an anesthesia gas regeneration system in which a low flow waste anesthesia gas collection unit, a compressor consisting of one or more compression stages, an anesthesia gas component from the waste anesthesia gas flow. A single-stage or multi-stage condenser / heat exchanger unit that removes air, a small cooling unit that cools the heat transfer fluid used as a refrigerant in the condenser, and a small turbine that captures the potential energy of the waste gas compressed before being released into the atmosphere, including. FIG. 16 illustrates the process and system in a schematic diagram, wherein an intermediate heat transfer fluid is used to liquefy the halocarbon components of the waste anesthetic gas and condense these gas components before releasing the waste anesthetic gas to the atmosphere. FIG. 17 illustrates the process and system in a schematic diagram, using the waste anesthetic gas fluoroether and other volatile halocarbon gas components as a heat sink for the process using a heat transfer fluid cooled by another cooling unit. Prior to release of the waste anesthetic gas to the atmosphere, it is separated from the waste anesthetic gas, followed by fractional distillation by sequentially thawing and collecting the resulting liquid halocarbon. FIG. 18 schematically illustrates a preferred embodiment of a self-contained waste anesthesia gas regeneration system, with a low flow anesthesia collection unit, a compressor, and a heat exchanger that removes anesthesia gas components from the waste anesthetic gas stream. / Condenser, a small cooling unit used to cool the heat transfer fluid used as a refrigerant in the condenser, and an expansion valve to introduce additional anesthetic gas condensate.

Claims (43)

A system that prevents the release of anesthetic gas components from a medical facility into the atmosphere:
A waste anesthetic gas collection unit (315, 330, 615, 630) for collecting waste anesthetic gas from an anesthesia device (312, 612), the waste anesthetic gas collection unit receiving the waste anesthetic gas from the anesthesia device A receiving chamber (332, 632) and a detector (340, 640) for detecting the presence of the waste anesthetic gas received in the chamber by measuring the difference between the pressure in the chamber and the outside atmospheric pressure A waste anesthetic gas collection unit comprising:
A collection inlet (316, 616) for collecting the waste anesthetic gas from the waste anesthetic gas collection unit (315, 330, 615, 630);
A heat exchanger / condenser (222, 322, 422, 522, 622) having an inlet and an outlet in fluid communication with the flow path (239, 339, 439, 539, 639) from the collection inlet (316, 616). The heat exchanger / condenser (222, 322, 422, 522, 622) also includes a cooling coil (236, 436A, 436B, 536) disposed therein, and the cooling coil (236, 436A). 436B, 536) is fluidly coupled to the flow path (227, 327, 427, 527, 627) to the cooling unit (270, 370, 570, 670) and the cooling coils (236, 436A, 436B, 536). ) Has an inlet, and the heat exchanger / condenser (222, 322, 422, 522, 622) is the heat exchanger / condenser (22 , 322,422,522,622) having at least one container for collecting liquefied anesthetic components from said waste anesthetic gas into a heat exchanger / condenser (222,322,422,522,622);
An inlet fluidly coupled to a flow path (227, 327, 427, 527, 627) from the outlet of the cooling coil (236, 436A, 436B, 536); and an inlet of the cooling coil (236, 436A, 436B, 536). A cooling unit (270, 370, 570, 670) having a flow path (221, 321, 421, 521, 621) to the inlet and an outlet fluidly coupled to the cooling coil (236, 436A, 436B, 536) cooling units (270, 370, 570, 670) for cooling the heat transfer fluid flowing therethrough;
system. The cooling unit (270, 370, 570, 670)
A compressor (272) for compressing the heat transfer fluid;
A heat exchanger (274) for cooling the compressed heat transfer fluid with a coolant;
An expansion valve (276) for reducing the pressure of the heat transfer fluid;
The system of claim 1. The waste anesthetic gas collection unit (330,630) are,
Depending on the presence of the waste anesthetic gas received in the chamber (332, 632), the chamber (332, 632) is selectively separable that periodically fluidly couples to a collection intake (316, 616). equipped with a flow path (334,634);
The chambers (332, 632) and the selectively separable flow paths (334, 634) cooperate to collect the waste anesthetic gas from the anesthesia device (312, 612) when it is not flowing out. Reduce air intake into the intakes (316, 616);
The system of claim 1. A compressor (342, 642) comprising at least one compression stage and raising the waste anesthetic gas to a pressure above atmospheric pressure;
The system of claim 1. An expansion valve (643) fluidly coupled to the outlet of the heat exchanger / condenser (222, 322, 422, 522, 622), the expansion valve (643) reducing the pressure of waste gas discharged to the atmosphere (646) )When;
A receiver container (645) fluidly coupled between the expansion valve (643) and an atmospheric discharge flow path (646) for collecting condensed liquefied anesthetic components by reducing the pressure of the waste gas A receiver container (645);
The system of claim 4. A turbine (344) fluidly coupled to the outlet of the heat exchanger / condenser (222, 322, 422, 522, 622), wherein the turbine (344) reduces the pressure of waste gas discharged to the atmosphere (346); ;
A receiver vessel (345) fluidly coupled between the turbine (344) and an atmospheric discharge channel (346) for collecting liquefied anesthetic components condensed by reducing the pressure of the waste gas A container (345);
The system of claim 4. A method for removing and separating gaseous anesthetics from waste anesthetic gas to prevent the release of gaseous anesthetics from medical facilities to the atmosphere:
Collecting a waste anesthetic gas flow from an anesthesia device (312, 612) by receiving the gas flow into a chamber (332, 632) having a pressure detector, which is received in the chamber (332, 632). Detecting (340, 640) the presence of the gas flow by measuring the difference between the pressure in the chamber and the external atmospheric pressure with the pressure detector ;
The step of cooling the gas flow by passing the gas flow through a cooling surface (236, 436A, 436B, 536) characterized by a surface temperature gradient such that the gas flow passes in a direction from high temperature to low temperature. Then, the gas flow conducts heat exchange with the heat transfer fluid through the cooling surface, the heat transfer fluid is heated by the heat exchange with the gas flow, and the heat transfer fluid is then cooled by the cooling unit (270). 370, 570, 670), and cooling;
Condensing the gaseous anesthetic from the gas stream;
Separating the condensed anesthetic from the gas stream;
Discharging the gas stream to the atmosphere (346, 446, 546, 646) without the condensed anesthetic agent;
Method. Collecting the waste anesthetic gas stream comprises :
Periodically fluidly coupling the chamber to a collection inlet (316, 616) by a flow path (334, 634) that is selectively separable depending on the presence of the gas flow received in the chamber (332, 632) A process of performing;
Further comprising the step of transferring selectively separable flow path (334,634) by intake the collecting the gas stream received in said chamber (332,632) to (316,616);
The chamber (332, 632) and the selectively separable flow path (334, 634) cooperate so that the waste anesthetic gas flow does not flow out of the anesthesia device (312, 612). Reduce atmospheric uptake to collection inlets (316, 616);
The method of claim 7. Further comprising compressing the waste anesthetic gas stream to a pressure above atmospheric using a compressor (342, 642) having at least one compression stage;
The method of claim 7. The step of condensing the gaseous anesthetic from the waste anesthetic gas stream is performed at a pressure and temperature at which the gaseous anesthetic is condensed as a solid;
The method of claim 7. Expanding the gas stream by a turbine (344) prior to atmospheric release (346);
Collecting the liquefied anesthetic component condensed by the step of expanding the gas flow by the turbine (344) in a receiver container (345);
The method of claim 9. A system that prevents the release of anesthetic gas components from a medical facility into the atmosphere:
A waste anesthesia gas collection unit (15A, 15B, 15C, 30A, 30B, 30C) for collecting waste anesthesia gas from an anesthesia apparatus (12A, 12B, 12C) , the waste anesthesia gas collection unit from the anesthesia apparatus A chamber (332, 632) for receiving the waste anesthetic gas and a detector for detecting the pressure of the waste anesthetic gas received in the chamber by measuring a difference between the pressure in the chamber and an external atmospheric pressure A waste anesthetic gas collection unit comprising (340, 640) ;
A vacuum manifold (16) that directs the waste anesthetic gas from the waste anesthetic gas collection unit (15A, 15B, 15C, 30A, 30B, 30C) to a compressor (42);
A compressor (42) comprising at least one compression stage for raising the waste anesthetic gas to a pressure above atmospheric pressure;
A heat exchanger / condenser (22) having an inlet fluidly coupled to a flow path (139, 239) from the compressor (42) and an outlet fluidly coupled to an atmospheric discharge flow path (46), wherein the heat The exchanger / condenser (22) also has a cooling coil (136, 236A, 236B) disposed therein, and the outlet of the cooling coil (136, 236A, 236B) is a flow path (127, 127) to the refrigerant reservoir. 227) and the cooling coil (136, 236A, 236B) has an inlet fluidly coupled to the flow path (121, 221) from the refrigerant source (120, 220), a heat exchanger / condenser (22) And comprising:
The heat exchanger / condenser (22) has at least one container (24A, 24B) for collecting anesthetic components liquefied from the waste anesthetic gas inside the heat exchanger / condenser (22);
system. An expansion valve (43) fluidly coupled to the outlet of the heat exchanger / condenser (22), wherein the expansion valve (43) reduces the pressure of the waste gas released to the atmosphere;
A receiver container (45) fluidly coupled between the expansion valve (43) and the atmospheric discharge channel (46) for collecting the condensed liquefied anesthetic component by reducing the pressure of the waste gas A container (45);
The system of claim 12. The waste anesthetic gas collection unit (15A, 15B, 15C, 30A , 30B, 30C) is,
Selectively separable to periodically fluidly couple the chamber (32A, 32B, 32C) to a vacuum manifold (16) in response to the presence of the waste anesthetic gas received in the chamber (32A, 32B, 32C) further comprising a flow path (34A, 34B, 34C);
The waste anesthetic gas flows out of the anesthesia apparatus (12A, 12B, 12C) in cooperation with the chamber (32A, 32B, 32C) and the selectively separable flow path (34A, 34B, 34C). Reducing atmospheric uptake to the vacuum manifold (16) when not
The system of claim 12. A turbine (44) fluidly coupled to the outlet of the heat exchanger / condenser (22), wherein the turbine (44) reduces the pressure of waste gas discharged into the atmosphere (46);
A receiver container (45) fluidly coupled between the turbine (44) and the atmospheric discharge channel (46) for collecting condensed liquefied anesthetic components by reducing the pressure of the waste gas (45) further comprising:
The system of claim 12. A method for removing and separating gaseous anesthetics from a waste anesthetic gas stream to prevent the release of gaseous anesthetics from a medical facility to the atmosphere:
Collecting the waste anesthetic gas flow from an anesthesia device (12A, 12B, 12C) by receiving the gas flow into a chamber (332, 632) having a pressure detector , the chamber (32A, 32B) 32C) detecting (40A, 40B, 40C) the presence of the gas flow received by measuring the difference between the pressure in the chamber and the external atmospheric pressure with the pressure detector. And process ;
Compressing the received waste anesthetic gas stream to a pressure above atmospheric using a compressor (42) having at least one compression stage;
Passing the compressed gas stream through a cooling surface (136, 236A, 236B) characterized by a surface temperature gradient such that the gas stream passes from a high temperature to a low temperature; cooling the compressed gas stream;
Condensing the gaseous anesthetic from the compressed gas stream;
Separating the condensed anesthetic from the compressed gas stream;
Discharging the gas stream free of the condensed anesthetic to the atmosphere (46);
Method. Collecting the waste anesthetic gas stream comprises :
Depending on the presence of the gas flow received in the chamber (32A, 32B, 32C), the chamber is periodically fluidly coupled to a vacuum manifold with a selectively separable flow path (34A, 34B, 34C). A process of performing;
Transferring the gas flow received in the chamber (32A, 32B, 32C) to a compressor (42) by the selectively separable flow path (34A, 34B, 34C) and the vacuum manifold (16); Comprising:
The chamber (32A, 32B, 32C) and the selectively separable flow path (34A, 34B, 34C) cooperate to allow the waste anesthesia flow to flow out of the anesthetic device (12A, 12B, 12C). Reducing the intake of atmospheric air into the vacuum manifold (16) when not present;
The method of claim 16. The step of condensing the gaseous anesthetic from the compressed gas stream is performed at a pressure and temperature at which the gaseous anesthetic is condensed as a solid;
The method of claim 16. The step of condensing the gaseous anesthetic from the compressed gas stream is performed at a pressure and temperature at which the gaseous anesthetic is condensed as a solid;
The method of claim 17. Expanding the gas stream with an expansion valve (43) before releasing it into the atmosphere (46);
Collecting the liquefied anesthetic component condensed by expanding the gas flow with the expansion valve (43) in a receiver container (45);
The method of claim 16. Expanding the gas stream with an expansion valve (43) before releasing it into the atmosphere (46);
Collecting the liquefied anesthetic component condensed by expanding the gas flow with the expansion valve (43) in a receiver container (45);
The method of claim 17. A waste anesthetic gas collection device (30) comprising:
A first chamber (32A) having an inflow portion and an outflow portion in fluid communication with each other, wherein the inflow portion of the first chamber is fluidly coupled to the discharge portion of the first anesthetic device (12A) and discarded A first chamber arranged to receive a gas flow comprising an anesthetic gas component therefrom;
A first exhaust valve (34A) having a first end fluidly coupled to the outlet of the first chamber and having a second end adapted to fluidly couple to a vacuum manifold (16). A first exhaust valve designed and arranged to selectively isolate the first chamber from the vacuum manifold ;
A first detector (40A) coupled to the first chamber by determining when the gas flow containing the waste anesthetic gas component flows into and exists in the first chamber ; Designed and arranged to detect the gas flow including the waste anesthetic gas component exhausted from a first anesthetic device , the first detector controls the first exhaust valve to control the first exhaust valve. A first detector operably coupled to the exhaust valve , wherein the first detector is present when the gas flow containing the waste anesthetic gas component flows into the first chamber. A pressure detector that determines by measuring the difference between the pressure of the first chamber and the external atmospheric pressure ;
When the first detector determines that the gas flow containing the waste anesthetic gas component flows into and exists in the first chamber, the first detector opens the first exhaust valve, and Fluidly connecting the outlet of the first chamber to the vacuum manifold to discharge the gas stream containing the waste anesthetic gas component from the first chamber to the vacuum manifold; and the first detector The first detector closes the first exhaust valve when not detecting the waste anesthetic gas component flowing out of the first anesthetic device ;
apparatus. The first exhaust valve is a solenoid driven valve;
The apparatus of claim 22. A vacuum manifold (16) fluidly coupled to the second end of the first exhaust valve (34A);
A waste anesthetic gas collector (22, 24, 26B, 20) fluidly coupled to the vacuum manifold and receiving a gas flow from the vacuum manifold, so as to remove the waste anesthetic gas component from the gas flow Further comprising a designed and arranged waste anesthetic gas collector;
The apparatus of claim 22. A vacuum manifold (16) fluidly coupled to the second end of the first exhaust valve (34A);
First and second anesthesia devices (12A, 12B) each having a discharge portion, wherein the inflow portion of the first chamber (32A) is fluidly coupled to the discharge portion of the first anesthetic device (12A) And a first and second anesthetic device;
A second chamber (32B) having an inflow portion and an outflow portion, wherein the inflow portion of the second chamber is fluidly coupled to the discharge portion of the second anesthetic device (12B), and the second chamber A second chamber arranged to receive a gas flow from the anesthetic device ;
A second chamber (32B) the outlet portion and the first second discharge valve having a second end that the an end vacuum manifold and fluidly coupled to the fluid coupling (34B), said first A second exhaust valve designed and arranged to selectively isolate two chambers from the vacuum manifold ;
A second detector (40B) coupled to the second chamber, wherein the second detector (40B) is configured to determine when a gas flow from the second anesthetic device flows into the second chamber and exists . Designed and arranged to detect the gas flow exiting from the second anesthetic device , the second detector being operably coupled to the second exhaust valve to control the second exhaust valve. A second detector;
When the second detector determines that the gas flow discharged from the second anesthetic device flows into the second chamber and is present, the second detector causes the second discharge valve to Open and fluidly couple the outlet of the second chamber to the vacuum manifold such that the gas flow from the second chamber is exhausted to the vacuum manifold, and the second detector is the second detector. When no gas flow from the anesthesia device is detected, the second detector closes the second exhaust valve;
Said first exhaust valve and the second discharge valve, when there is no pre-Symbol first chamber or gas stream that is present to flow into the second chamber, cooperatively, to the exhaust manifold of the atmosphere Limit uptake;
The apparatus of claim 22. A method for collecting waste anesthetic gas components from a gas flow from an anesthetic device (12) comprising:
Receiving the gas flow from the anesthetic device into a chamber (32);
Detecting the presence of the gas flow received in the chamber by measuring the difference between the pressure in the chamber and atmospheric pressure using a pressure gauge coupled to the chamber ;
In response to the detection of the presence of said gas stream received in said chamber, by selectively separable flow path (34), the steps of the flow body coupling the chamber to the vacuum manifold (16);
Transferring the gas flow received in the chamber to the waste anesthetic gas collector (22, 24, 26B, 20) through the selectively separable flow path and the vacuum manifold;
Isolating the chamber from the vacuum manifold by the selectively separable flow path when the presence of a gas flow received in the chamber is not detected;
Removing the waste anesthetic gas component from the gas flow with the waste anesthetic gas collection device;
The chamber and the selectively separable flow path cooperate to reduce the uptake of atmospheric gas into the vacuum manifold when there is no gas flow exiting the anesthetic device;
Method. Enabling fluid communication with the selectively separable flow path when the presence of the gas flow received in the chamber is detected;
Disabling fluid communication with the selectively separable flow path when the presence of the gas flow received in the chamber is not detected;
27. The method of claim 26. The selectively separable flow path includes a solenoid driven discharge valve:
Opening the discharge valve with the pressure gauge when the pressure in the chamber is higher than the atmospheric pressure;
Allowing the pressure gauge to close the exhaust valve when the pressure in the chamber is not higher than the atmospheric pressure;
27. The method of claim 26 . Further comprising driving the discharge valve in proportion to the differential pressure;
30. The method of claim 28. A plurality of anesthesia devices corresponding to the plurality of inlet points of the vacuum manifold, each of the anesthesia devices corresponding to each of the inlet points based on the presence of a detected gas flow ; Further comprising controlling the inflow at the entry point;
27. The method of claim 26. A method for removing and separating a plurality of gas components from a gas mixture comprising:
Collecting the gas mixture in the chamber, the chamber detecting the pressure of the gas mixture in the chamber by measuring a difference between the pressure in the chamber and an external atmospheric pressure. Including an arrayed pressure detector;
Transferring the gas mixture to a collection inlet when the presence of the gas mixture is detected in the chamber;
Cooling the gas mixture by passing the gas mixture through a cooling surface (36) characterized by a surface temperature gradient such that the gas mixture passes from high to low temperatures;
Vapor deposition by condensing a gaseous first component of the gas mixture as a solid on a first portion (60, 62) of the cooling surface, wherein the first component is a first melting point. Wherein the first portion (60, 62) is characterized by a first temperature below the first melting point;
Thereafter, vapor deposition is performed by condensing the gaseous second component of the gas mixture as a solid onto the second portion (63, 64) of the cooling surface, wherein the second component is the second component. The second part (63, 64) is characterized by a second temperature lower than the second melting point and lower than the first melting point;
Then heating the cooling surface (36);
Then, thawing the vapor deposited solid second component from the second portion (63, 64) of the cooling surface (36);
Then collecting said second component in a second container (24B);
Then, thawing the vapor deposited solid first component from the first portion (60, 62) of the cooling surface (36);
And thereafter collecting the first component in a first container (24A);
Method. Melting the deposited solid second component into a liquid phase;
Collecting the second component of the liquid in the second container (24B);
Then, melting the vapor deposited solid first component into a liquid phase;
And thereafter collecting the first component of the liquid in the first container (24A);
32. The method of claim 31. Melting the deposited solid second component into a liquid phase;
Collecting the second component of the liquid in the second container (24B);
Then sublimating the vapor deposited solid first component into the gas phase;
And thereafter collecting the first component of the vapor in the first container (24A);
32. The method of claim 31. Sublimating the vapor deposited solid second component into the gas phase;
Then collecting the second component of the vapor into the second container (24B);
Then, melting the vapor deposited solid first component into a liquid phase;
And thereafter collecting the first component of the liquid in the first container (24A);
32. The method of claim 31. Sublimating the vapor deposited solid second component into the gas phase;
Then collecting the second component of the vapor into the second container (24B);
Then sublimating the vapor deposited solid first component into the gas phase;
And thereafter collecting the first component of the vapor in the first container (24A);
32. The method of claim 31. A method for removing and separating a plurality of gas components from a waste anesthetic gas mixture comprising nitrogen, oxygen and a plurality of halocarbon components:
Collecting said waste anesthetic gas mixture into a chamber so that said chamber detects the presence of said gas mixture in said chamber by measuring the difference between the pressure in said chamber and an external atmospheric pressure Having a pressure detector arranged and designed; and
Transferring the waste anesthetic gas mixture to a collection inlet when the presence of the waste anesthetic gas mixture is detected in the chamber;
Cooling the waste anesthetic gas mixture by passing the waste anesthetic gas mixture through a cooling surface (36) characterized by a surface temperature gradient such that the gas mixture passes from a high temperature to a low temperature;
Solidifying a gaseous first halocarbon component of the waste anesthetic gas mixture onto a first portion (60, 62) of the cooling surface (36), the gaseous first halocarbon A component is characterized by a first halocarbon melting point and the first portion (60, 62) is characterized by a first temperature lower than the first halocarbon melting point;
Solidifying the gaseous second halocarbon component of the waste anesthetic gas mixture onto the second portion (63, 64) of the cooling surface (36), the gaseous second halocarbon The component is characterized by a second halocarbon melting point, and the second portion (63, 64) is characterized by a second temperature that is lower than the second halocarbon melting point and lower than the first temperature. And process;
Then heating the cooling surface (36);
Melting the solidified second halocarbon component from the second portion (63, 64) of the cooling surface (36) into a liquid phase;
Collecting the liquid second halocarbon component in containers (24A, 24B);
Then melting the solidified first halocarbon component from the first portion (60, 62) of the cooling surface (36) into a liquid phase;
Collecting the liquid first halocarbon component in a container (24A, 24B);
Method. The waste anesthetic gas mixture comprises at least one gaseous anesthetic component;
Solidifying the gaseous anesthetic component of the waste anesthetic gas mixture onto the third portion (62, 63, 64) of the cooling surface (36), wherein the gaseous anesthetic component is characterized by an anesthetic melting point; And wherein the third portion (62, 63, 64) is characterized by a third temperature below the melting point of the anesthetic agent;
Thereafter, the solidified anesthetic component is sublimated into the gas phase from the third portion (62, 63, 64) of the cooling surface (36);
And thereafter collecting the gaseous anesthetic component in a container (24C);
38. The method of claim 36. Cooling the cooling surface (36) by heat exchange with a quantity of liquid oxygen and warming;
And thereafter using a warmed amount of liquid oxygen in the medical facility (110);
37. The method of claim 36.   A mechanical relief valve fluidly coupled to the first chamber;
  The apparatus of claim 22.   A mechanical vacuum breaker fluidly coupled to the first chamber;
  The apparatus of claim 22.   The first detector is operably connected to the first exhaust valve by a DC low voltage circuit;
  The apparatus of claim 22.   The first discharge valve is designed and arranged to provide a response proportional to the pressure difference detected by the pressure detector, the first discharge valve opens small for small pressure differences and is large Wide open for pressure difference;
  The apparatus of claim 22.   The waste anesthetic gas collection device includes a condenser (22) and a low temperature heat sink, the low temperature heat sink condensing the waste anesthetic gas component from the gas flow in the capacitor;
  25. The apparatus of claim 24.

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