JP2010184028A - Steam sterilizer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve such problems that it takes much time to lower in-chamber temperature to the safe level and sterilization processing is not efficiently performed when the processing is continuously performed a plurality of times since outer air is taken-in to cool the inside of the chamber after the termination of a drying process and a lid on the front surface of the chamber is opened after the in-chamber temperature is lowered to the safe level though a band shape electric heater is arranged on the outer surface of the chamber to heat the chamber in the drying process to be performed after a sterilizing process when an object to be sterilized, which is stored in the chamber, is sterilized under high pressure by high-temperature steam. <P>SOLUTION: The heat exchanger of a refrigeration unit is arranged in the chamber, which replaces the conventional band shape electric heater. In the drying process, the chamber is heated by the heat exchanger. When the inside of the chamber is cooled after the termination of the drying process, the chamber is cooled by the heat exchanger. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

The present invention relates to a steam sterilizer that is mainly installed in a hospital or the like and sterilizes an object to be sterilized such as a medical instrument under high-temperature steam, and particularly relates to a technique that employs a refrigeration apparatus for heating and cooling in a chamber.

In a steam sterilizer, the water in the chamber is heated and evaporated with an electric heater located at the bottom of the chamber, and sterilization is performed using high-temperature steam under high pressure under medical conditions such as medical equipment stored in the chamber. In a drying process performed after the process, a band-shaped electric heater is provided on the outer surface of the chamber so as to heat the chamber. (See Patent Document 1).

Japanese Patent Laid-Open No. 2005-160771

The thing of this patent document 1 is dried with a band-shaped electric heater in a drying process.
After the drying process is completed, outside air is taken in to cool the inside of the chamber, and when the inside of the chamber is lowered to a safe temperature, the lid on the front surface of the chamber can be opened. For this reason, it takes a considerable time until the inside of the chamber is lowered to a safe temperature, and the efficiency is poor when sterilization is continuously performed a plurality of times.

In view of this point, the present invention provides a heat exchanger for a refrigeration apparatus instead of the conventional band-shaped electric heater, and in the drying process, the chamber is heated by the heat exchanger, and the chamber after the drying process is completed. When the inside is cooled, the chamber is cooled by this heat exchanger. As a result, not only the chamber can be heated, but also the inside of the chamber can be effectively cooled, and an apparatus suitable for performing sterilization treatment continuously a plurality of times can be provided.

A first invention is a steam sterilizer that heats and evaporates water accumulated at the bottom of a chamber by a heater disposed at the bottom of the chamber, wherein a heat exchanger of a refrigeration apparatus is provided on the outer surface of the chamber, It is heated in the heat exchanger by the heating operation of the refrigeration apparatus,
The chamber is cooled by the heat exchanger by a cooling operation of the refrigeration apparatus.

A second invention is a steam sterilizer that heats and evaporates water accumulated at the bottom of the chamber by a heater disposed at the bottom of the chamber. The compressor, the flow path switching means, the first heat exchanger, the decompression means, the second heat A refrigerating apparatus having a refrigerating cycle configured by connecting an exchanger in an annular shape, the second heat exchanger being provided on an outer surface of the chamber, and the chamber being disposed in the second heat exchanger by heating operation of the refrigerating apparatus. The chamber is heated by a heat radiation action, and the chamber is cooled by a heat absorption action of the second heat exchanger by a cooling operation of the refrigeration apparatus.

A third invention is characterized in that, in the first invention or the second invention, the refrigeration apparatus is heated in the drying process, and the refrigeration apparatus is cooled at the end of the drying process.

The present invention is provided with a heat exchanger for a refrigeration apparatus instead of the conventional band-shaped electric heater, and in the drying process, the chamber is heated by the heat exchanger of the refrigeration apparatus, and the chamber is cooled after the drying process is completed. In some cases, the chamber is cooled by the heat exchanger, so that the chamber can be effectively cooled as well as heated, which is suitable for a case where sterilization is continuously performed a plurality of times. An apparatus can be provided.

1 is an overall piping diagram of a steam sterilizer according to the present invention. It is a partial cross section figure of the chamber concerning the present invention. It is a block diagram of the freezing apparatus which concerns on this invention.

[Example]
An embodiment of the steam sterilizer of the present invention will be described with reference to the drawings. In FIG. 1, reference numeral 1 is a steam sterilizer, 4 is a horizontal cylindrical chamber arranged in the steam sterilizer 1 and having an opening 4 </ b> C formed on the front surface, and 5 is a sterilization of a sheathed heater configuration arranged and fixed at the inner bottom of the chamber 4. Heater. 6
Is a pallet on which a basket 7 containing an object to be sterilized is placed above the sterilization heater 5 in the chamber 4, 8 is a lid for opening and closing the front opening 4 </ b> C of the chamber 4, and 9 is fixed to the wall material of the chamber 4. The coupling 10 is a pressure gauge attached to the end of the pipe 11 connected to the coupling 9, and 12 is attached to a part of the pipe 11 and is opened before the inside of the chamber 4 becomes abnormal pressure to prevent pressure rise. It is a safety valve. As will be described later, the chamber 4 has a barrier 4D in the front opening 4C so that water poured into the chamber 4 does not spill from the front opening 4C.
It has.

Reference numeral 13 denotes a later-described tray serving as a base provided in the lower space of the steam sterilizer. 14 is tray 1
3 is a water-sealed vacuum pump fixed to the bottom plate S1 fixed to the bottom of the steam sterilizer 1 adjacent to
An intake portion 16 that communicates with the inside of the chamber 4 through a pipe 15, a water supply portion 17, and a drainage portion 18.
have.

19 and 20 are leak valves and vacuum valves for adjusting the degree of vacuum of the water-sealed vacuum pump 14 provided in a part of the pipe 15, 21 is an intake filter that communicates with the chamber 4 through the pipe 22, and 23 is the pipe 22. A check valve provided in a part prevents the air in the chamber 4 from being exhausted into the atmosphere. 24 is a water supply filter attached to the bottom wall of the chamber 4, 25 is a water supply / drainage pipe having one end connected to the water supply filter 24 and a part of the water supply / drainage valve 26 attached thereto, 27
The check valve 28 and the exhaust valve 29 are attached to a part of the exhaust pipe, one end of which is connected to the chamber 4, and the other end of each of the water injection pipe 25 and the exhaust pipe 27 is connected to the cheese 30.

31 is a water injection pipe, 33 is a water supply pipe having one end connected to the water supply unit 17 and the other end opened.
Reference numeral 4 denotes a drainage pipe having one end connected to the drainage section 18 and the other end opened. 35 is made of polypropylene in which a predetermined amount of heating water used for sterilization in the chamber 4 is stored, and has an internal volume of about 20
It is a pouring / draining tank of about liters, and a tip opening portion 31A of a pouring / draining pipe 31 with a muffler 32 attached to the tip is introduced. 36 is a water-sealing water supply tank for storing water sealing and cooling water for the water-sealed vacuum pump 14, and the other end of the water supply pipe 33 connected to the water supply unit 17 and the drainage unit 18.
The internal capacity of the drain pipe 34 connected to the other end is about 20 liters. The drainage tank 35 and the water-sealing water supply tank 36 are placed on the tray 13. The temperature in the chamber 4 is detected by a temperature sensor 37.

In the present invention, the heat exchanger 38 of the refrigeration apparatus RS is attached so as to wrap the outer surface of the chamber 4. This is because the chamber 4 is heated by a drying heater in the prior art.
In the present invention, the heat exchanger 38 not only heats the chamber 4 but also cools the chamber 4. As will be described later, since this cooling action forcibly lowers the temperature in the chamber 4 after the sterilization operation of the article to be sterilized is completed, the time for performing a series of sterilization steps can be shortened. The effect can be demonstrated.

For this reason, as shown in FIG. 2, the heat exchanger 38 of the refrigeration apparatus RS is attached so as to wrap the outer surface of the chamber 4, and the heat exchanger 38 and the outer surface of the chamber 4 are covered with a heat insulating material DN. is there. The refrigeration apparatus RS is switched between a heating operation in which the chamber 4 is heated by the heat exchanger 38 and a cooling operation in which the chamber 4 is cooled by the heat exchanger 38. Although this kind of refrigeration apparatus RS is well-known, one structure of refrigeration apparatus RS is shown in FIG.

In FIG. 3, the refrigeration apparatus RS includes a compressor 40 that compresses refrigerant, a four-way valve 41 as a flow path switching unit, a first heat exchanger 42, an electric expansion valve 43 as a decompression unit, and a second heat exchanger 38. Are connected in an annular shape to form a refrigeration cycle, and a fan 44 is arranged with respect to the first heat exchanger 42. The refrigeration apparatus RS may be disposed at the bottom of the steam sterilizer 1. As one configuration, the compressor 40, the first heat exchanger 42, and the fan 4 are disposed on the bottom plate S 1 adjacent to the water ring vacuum pump 14.
Place 4 etc.

In the cooling operation, the refrigeration apparatus RS enters the first heat exchanger 42 through the four-way valve 41 and the outside air sent by the fan 44, as indicated by the solid arrow in FIG. After being dissipated and condensed in the first heat exchanger 42, the electric expansion valve 43 adiabatically expands and enters the second heat exchanger 38. The liquid refrigerant that has entered the second heat exchanger 38 evaporates and evaporates with the chamber 4, and after cooling the chamber 4 by the endothermic action thereby, the refrigerant enters the compressor 40 through the four-way valve 41, It is compressed again by the compressor 40 and the above circulation is repeated. As described above, by this circulation, the second heat exchanger 38 becomes a cooler, and the chamber 4 is cooled at the low temperature.

In the heating operation, the refrigeration apparatus RS has a compressor 4 as shown by a broken line arrow in FIG.
The high-temperature refrigerant compressed at 0 enters the second heat exchanger 38 through the four-way valve 41 switched from the cooling operation mode, and exchanges heat with the chamber 4 to perform a heat radiation action, whereby the chamber 4 is heated. As a result, the temperature of the high-temperature refrigerant is lowered, and in that state, the electric expansion valve 43, the first heat exchanger 42, and the four-way valve 41 are entered into the compressor 40, where it is compressed again by the compressor 40 and the above circulation is repeated. . By this circulation, the second heat exchanger 38 becomes a heater as described above, and the chamber 4 is heated by the high temperature.

The steam sterilizer 1 includes a control circuit unit 45 that controls a series of sterilization operations. The control circuit unit 45 has a microcomputer configuration that operates according to a program stored in the memory 46, and an operation unit that performs various settings. 47 is connected. Since the refrigeration apparatus RS is also controlled by the control circuit unit 45, based on the conditions set by the operation unit 47 and the temperature detection of the temperature sensor 37 or the temperature sensor 48 described later, the control circuit unit 45 causes the compressor 40 or Operation control of the refrigeration apparatus RS is performed by ON-OFF operation of the fan 44 or the like. Compressor 40
If it is an inverter control type, the rotation speed of the compressor 40 is controlled. Further, the opening degree of the electric expansion valve 43 is controlled by the control circuit unit 45 based on the temperature detection of the temperature sensor 37 or a temperature sensor 48 described later.

Next, a series of sterilization operations will be described. This series of sterilization operations is based on the operation of the control circuit unit 45 in accordance with a program by operating the start key of the operation unit 47 after performing necessary settings such as sterilization time, sterilization temperature, and drying time by the operation unit 47. Done. Items to be sterilized (
A basket 7 containing gauze or the like is placed in the chamber 4 and placed on the pallet 6. The lid 8 has a configuration related to a lock solenoid (not shown).

In a state where the power of the steam sterilizer 1 is applied, the operation of the control circuit unit 45 turns on (excites) the lock solenoid and releases the lid 8 from the locked state. In this state, after the object to be sterilized is accommodated in the chamber 4 and the lid 8 is closed, a predetermined setting such as a sterilization time is performed by the operation unit 47, and the lock solenoid is turned off when the start button is operated. The cover 8 is locked by the lock pin so as not to open.
Then, the vacuum valve 20 is opened and the water-sealed vacuum pump 14 starts operation, and air is introduced into the chamber 4 through the air supply filter 21 and the air supply valve 39 while evacuating.
At this time, by the temperature detection of the temperature sensor 37, it becomes a preheating step of heating the sterilized object intermittently by the heat generated by the sterilization heater 5 and intermittently by the heating operation of the refrigeration apparatus RS. Prevents condensation on objects and improves drying performance. Intermittent refrigeration equipment RS
The heating operation is performed by turning the compressor 40 on and off, and if it is an inverter control type, it is performed by controlling the rotational speed of the compressor 40.

After about 10 minutes have passed since the start of the preheating process, the heating operation by the refrigeration apparatus RS is stopped,
The air supply valve 39 is closed and the water injection / drainage valve 26 is opened.
Water is sucked into the chamber 4 from the muffler 32 through the pouring / draining pipe 31, the cheese 30 and the water absorption filter 24. When a predetermined amount of water is stored in the chamber 4 so that the sterilization heater 5 is submerged by this water injection, the water injection / drainage valve 26 is closed, and the water-sealed vacuum pump 14 is further evacuated, so that the water-sealed vacuum pump 14 A preliminary vacuum process for evacuating the air in the chamber 4 is performed.

After about 3 minutes from the start of the preliminary vacuum process, the operation of the water ring vacuum pump 14 is stopped,
The vacuum valve 20 is closed, and the sterilization heater 5 proceeds to a heating process in which heat is generated with the total amount of heat. At this time, residual air that has not been exhausted during the preliminary vacuum process is exhausted from the exhaust valve 29 for several minutes after the temperature in the chamber 4 reaches 99 ° C. After that, when the sterilization heater 5 continues to generate heat and the inside of the chamber reaches 132 ° C., the heating process ends and the process proceeds to the sterilization process. In the sterilization process, the sterilization process is performed over a predetermined sterilization time by controlling energization to the sterilization heater 5 so that the inside of the chamber 4 reaches a predetermined sterilization temperature (for example, 132 ° C.) under saturated vapor pressure. Do.

When a predetermined sterilization time has elapsed, heat generation is stopped when the sterilization heater 5 is turned off, and the sterilization process is completed. Upon completion of the sterilization process, the pouring / draining valve 26 is opened, and the process proceeds to the exhaust process. Due to the transition to the exhaust process, the water injection / drainage valve 26 is opened, and the chamber 4
The high temperature water passes through the pouring pipes 25, 31 and flows into the pouring tank 35. When the process goes to the exhaust process and the temperature in the chamber 4 decreases to 105 ° C., the drain / drain valve 26 is closed and the exhaust valve 29 is opened. In this way, the water in the chamber is drained and returned to the pouring / draining tank 35.

When the temperature in the chamber is lowered to 100 ° C., the vacuum valve 20 is opened again, the operation of the water-sealed vacuum pump 14 is started, the sterilization heater 5 is heated, and the refrigeration apparatus RS is heated, and the air supply valve 39 is temporarily opened, air is introduced into the chamber 4, and a drying process for drying the sterilized material is executed.

When the predetermined drying time has elapsed, the energization to the sterilization heater 5 is stopped, the heating operation by the refrigeration apparatus RS is stopped, the vacuum valve 20 is closed, and the operation of the water ring vacuum pump 14 is also stopped. The process ends. At the end of the drying process, the air supply valve 39 is opened,
The temperature in the chamber 4 detected by the temperature sensor 37 is the ambient temperature (for example, 20 ° C.)
When the pressure drops below and the pressure in the chamber 4 returns to atmospheric pressure based on detection by a pressure sensor (not shown), the lock solenoid is turned on (excited), and the lid 8 is released from the locked state. For this reason, the lid 8 can be opened to take out the object to be sterilized. In this way, a series of sterilization operations are completed.

As described above, the water-sealed vacuum pump 14 is operated during the preheating step, the prevacuum step, and the drying step, and the chamber 4 is evacuated. The water supplied from the tank 36 enters the vacuum pump 14 from the water supply unit 17 and functions as a water seal, and then rises in temperature and is discharged from the drain 18 into the water seal water supply tank 36.

In the above series of operations, when the drying process is completed, a cooling operation for cooling the inside of the chamber 4 by the refrigeration apparatus RS is started. This cooling operation is performed by detecting the temperature sensor 37 so that the temperature in the chamber 4 is a predetermined temperature (safe temperature when taking out the object to be sterilized) (
For example, it stops when the temperature falls to 20 ° C.) or below the ambient temperature. The cooling operation in this system is performed when the drying process by the heat generation of the sterilization heater 5 and the heating operation by the refrigeration apparatus RS is completed.

In the conventional type in which the chamber 4 is heated with a drying heater, the drying process is completed and the temperature in the chamber 4 is due to the introduction of outside air until the temperature in the chamber 4 becomes a low temperature that is safe for taking out the sterilized object. It takes a long time to reach a safe low temperature. However, in the present invention, the temperature is forcibly lowered by the cooling operation by the refrigeration apparatus RS, so the time until the temperature in the chamber 4 becomes safe for taking out the sterilized material after the drying process is completed is shortened. Therefore, the working efficiency when performing the sterilization operation continuously is improved, which is preferable.

In the above control operation, the energization control to the sterilization heater 5 and the heating operation control by the refrigeration apparatus RS are performed by detecting the temperature in the chamber 4 by the temperature sensor 37 and operating the control circuit unit 45 thereby. . As an alternative method, as shown in FIG. 2, heat exchange is performed in a configuration in which the outer surface of the chamber 4 is covered with a heat insulating material DN so as to cover the heat exchanger 38 arranged to heat the wall of the chamber 4. The control circuit unit 45 can control the operation of the refrigeration apparatus RS based on the temperature detected by the temperature sensor 48 formed of a thermistor that detects the temperature on the outlet side of the container 38. For this reason, the control operation is the operation control of the refrigerating apparatus RS based on the temperature sensor 48 instead of the operation control of the refrigerating apparatus RS based on the temperature sensor 37 described in the above embodiment.

In the steam sterilizer according to the present invention, the chamber 4 shown in the above embodiment is not limited to the horizontal configuration, and includes various forms within the technical scope of the present invention. For this reason, the structure of the refrigerating apparatus which performs a heating operation and a cooling operation is not limited to the structure shown in the said Example. In addition, an electronic cooling device using a Peltier element is used as a heat exchanger of the refrigeration apparatus, and a Peltier element is attached to the chamber 4 instead of the heat exchanger 38, and the energization direction to the Peltier element is reversed from the normal direction. The cooling operation and the heating operation can be performed in the same manner as described above.

DESCRIPTION OF SYMBOLS 1 ... Steam sterilizer 4 ... Horizontal chamber 5 ... Heater for sterilization 14 ... Water-sealed vacuum pump 15 ... Pipe 16 ... Air intake part 17 ··· Water supply section 18 ··· Drainage portion 24 ··· Water supply filter 25 · · · Water injection pipe 25 · · · Water injection pipe 31 · · · Water discharge pipe 33 · · · Water for sealing Water supply pipe 34 ··· Drain pipe 35 ··· Pourage tank 36 · · · Water seal water supply tank 37 · · · Temperature sensor 38 ··· Second heat exchanger 40 ··· Compressor 41... Channel switching means 42... First heat exchanger 43 ... Pressure reducing means 44 ... Fan 45 ... Control circuit section 46 ... Memory 47 ... Operating unit 48 ... Temperature sensor RS ... Freezer

Claims (3)

In a steam sterilizer that heats and evaporates water accumulated at the bottom of the chamber by a heater disposed at the bottom of the chamber, a heat exchanger of a refrigeration apparatus is provided on the outer surface of the chamber, and the heating of the chamber is a heating operation of the refrigeration apparatus The steam sterilizer is heated by the heat exchanger according to claim 1, and the chamber is cooled by the heat exchanger by a cooling operation of the refrigeration apparatus. In a steam sterilizer that heats and evaporates water accumulated at the bottom of the chamber by a heater disposed at the bottom of the chamber, the compressor, the flow path switching means, the first heat exchanger, the decompression means, and the second heat exchanger are annularly formed. A refrigerating apparatus connected to form a refrigerating cycle, wherein the second heat exchanger is provided on an outer surface of the chamber, and the chamber is heated by a heat radiation action of the second heat exchanger by a heating operation of the refrigerating apparatus. And the chamber is cooled by the endothermic action of the second heat exchanger by the cooling operation of the refrigeration apparatus. The steam sterilizer according to claim 1 or 2, wherein the refrigeration apparatus is heated in the drying process, and the cooling operation of the refrigeration apparatus is performed at the end of the drying process.

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