JP2010046107A - Treatment device of exhaled gas - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a treatment device of exhaled gas for removing and safely discharging a removal object component by removing moisture from the exhaled gas discharged from an artificial respiratory apparatus mainly and attaining stable humidity. <P>SOLUTION: The treatment device of the exhaled gas includes a moisture removal means 4 for cooling the exhaled gas containing the removal object component by a cooling means 10 and dew-condensing and reducing the moisture contained in the exhaled gas, and the exhaled gas from which the moisture is reduced in the moisture removal means 4 is brought into contact with an adsorbent and the removal object component is removed. Thus, the need of a filling cylinder for filling a large amount of silica gel which is necessary in the conventional art is eliminated to achieve downsizing, the time and labor of exchange work of the silica gel are eliminated, and the decline of adsorption capacity due to the sticking of dew condensation water to the adsorbent and the obstruction of the discharge of the exhaled gas due to the sticking of the dew condensation water inside piping are eliminated. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an expiratory gas processing apparatus for safely discharging expiratory gas containing nitric oxide used in a ventilator or the like.

  In general, pulmonary arterial nitric oxide (NO) inhalation therapy is considered effective for patients with persistent pulmonary hypertension (PPHN) with pulmonary artery contraction. (Non-Patent Document 1). The therapy has already been carried out in the United States, and it is started by the seventh day after birth, and NO inhalation is continuously carried out for 14 days from the start of administration (Non-patent Document 2). In addition, a clinical trial in which the administration period is 4 days has been carried out (Non-patent Document 3).

However, when the therapy is performed, excess NO-containing gas contained in the exhaust gas from the ventilator after NO administration is exhausted to the hospital room. NO itself may be harmful depending on the amount and concentration of contact with the human body, and there are concerns about health hazards to medical workers. In addition, NO ₂ generated from NO and oxygen may be easily generated inside and outside the apparatus due to the reaction with surplus NO and oxygen due to the therapy, but this may cause redness of the skin and the respiratory system. It is a substance that induces harmful effects such as organ irritation due to inhalation into the body and is also concerned about carcinogenicity, and is more harmful than NO.

For example, at the American Conference of Industrial Industrial Hygienists (ACGIE), the time-weighted average concentration of NO and NO ₂ is defined as 25 ppm and NO ₂ as 3 ppm for the limit amounts of NO and NO ₂ (non-patent literature) 4). In Patent Document 1 (JP-A-8-47533), the allowable concentration of the industry is 25 ppm, NO ₂ and 5ppm if NO.

In fact, in Japan, as a condition for participation in the “Newborn NO Inhalation Therapy Study Group”, it is required to take sufficient measures for environmental pollution in the medical field, and NO and NO ₂ elimination are considered indispensable (non- Patent Document 5).

Accordingly, since the NO and NO ₂ is contained in the exhaled gas and excess gas after NO administration, the time of release and exhalation to the atmosphere, such as a hospital room, have to harm both dividing NO and NO ₂ is there.

As a prior art, for example, in Patent Document 1 (Japanese Patent Laid-Open No. 8-47533), NO is adsorbed and detoxified by a chemical adsorbent and NO ₂ is adsorbed and detoxified by a chemical adsorption effect of surface-treated activated carbon. Further Patent Document 2 (JP 2003-339872), to the detriment adsorbed dividing the NO and NO ₂ by adsorption on activated carbon.

Neonatal Studies 3rd Edition, written by Hiroshi Nishida, Medical Shoin Co., Ltd. 264-266, (2004) NO administration device “INOmax” package insert, INO Therapeutics (USA), (2007) REESE H. CLARK et al, The New England Journal of Medicine, Vol. 342, no. 7, p. 469-474, (2000) 2001 TLVs and BEIs, Japan Work Environment Measurement Association, (2002) Separate Volume, History of Medicine NO and Pathology, Tomio Okamura, Bio-Dental Publishing Co., Ltd. 87-92, (2004) JP-A-8-47533 JP 2003-339872 A

  Usually, in a ventilator used for the therapy, inhalation is heated and humidified to 37 ° C. and 100% RH in order to protect the airway when introducing gas into the living body. Furthermore, due to the moisture by the patient's living body, the breath gas from the patient is saturated with moisture. On the other hand, in the intensive care unit using the NOx abatement apparatus as disclosed above, the use environment is about 30 ° C. and 70% RH. If the dehumidifying step is not performed, moisture in the exhalation will be condensed in the apparatus. As described above, when condensed water adheres to the adsorbent, the effective adsorption area is reduced and the adsorption capacity is greatly reduced. Furthermore, if condensed water adheres to the inside of the piping of the apparatus, the piping may be blocked, preventing the smooth discharge of exhaled air, and hindering appropriate treatment.

  However, in the method disclosed in Patent Document 1 (Japanese Patent Laid-Open No. 8-47533), an exhaled gas dehumidifying step is not provided before the NOx adsorption and detoxifying step. In order to control the pressure resistance, exhaled gas is mixed with the atmosphere before adsorption removal of NOx, and as a result, it may be possible to reduce the humidity somewhat. Therefore, there is a possibility that the piping in the apparatus may be blocked, and it cannot be said that sufficient dehumidification is performed. In order to prevent dew condensation in the pipe, it is desirable that the exhaled breath gas after dehumidification is kept at a relative humidity of about 50% or less at 30 ° C.

  Therefore, in Patent Document 2 (Japanese Patent Application Laid-Open No. 2003-339872), silica gel is used to remove moisture in exhaled breath. However, although adsorption dehumidification itself with silica gel is possible, there is a problem that a considerable amount of silica gel is required and the entire apparatus becomes large. In addition, the dehumidification ability of silica gel reaches saturation in a relatively short time by continuous use and needs to be replaced with a new one, which is very troublesome for an artificial respirator that requires continuous operation. Furthermore, with silica gel, immediately after starting dehumidification with new silica gel, the humidity of the exhaled gas may decrease too much and the adsorption capacity of the NO adsorbent may not be obtained sufficiently, and the silica gel accumulates moisture and becomes nearly saturated. On the contrary, the above-mentioned dew condensation may occur due to insufficient dehumidification. As described above, in silica gel, the humidity of the exhaled gas cannot be controlled, and the exhaled gas having a stable humidity cannot be supplied to the NO adsorbent, which may make the adsorbent adsorption performance unstable.

  On the other hand, as a dehumidification method not using silica gel, for example, a method of heating NOx-containing exhaled gas discharged from a ventilator to a high temperature and simultaneously performing dehumidification and detoxification with a catalyst is conceivable. This equipment may be used in hospitals, considering the possibility of secondary disasters such as ignition. It is not desirable to operate the system at this point.

  Furthermore, in Patent Document 1 (Japanese Patent Laid-Open No. 8-47533), the orifice is exchanged for a change in the flow rate of the ventilator. Difficult to do. As a result, an unintended auto-peep may occur with respect to the exhalation valve of the ventilator, and the ventilator may malfunction.

In addition, regarding adsorption detoxification of NO and NO ₂ , in Patent Document 2 (Japanese Patent Laid-Open No. 2003-339872), adsorption detoxification is performed using activated carbon, but in general, the adsorption rate of NO to activated carbon is considered to be low, In our test, as shown in Table 1 below, the gas having an NO concentration of 80 ppm at the inlet of the adsorption tower is not less than 5.4 ppm at the outlet, so that it is difficult to say that sufficient detoxification has been achieved.

  The present invention has been made in view of such circumstances, and by removing moisture from the exhaled gas mainly discharged from the ventilator to obtain a stable humidity, the removal target component can be stably removed. An object of the present invention is to provide a treatment apparatus for safely discharged exhaled gas.

  In order to achieve the above object, the apparatus for processing an exhaled gas of the present invention includes a moisture removing unit that cools an exhaled gas containing a component to be removed by a cooling unit to condense and remove moisture contained in the exhaled gas, The gist is to remove the component to be removed by bringing the exhaled gas from which moisture has been removed by the moisture removing means into contact with the adsorbent.

  That is, the present invention cools the exhaled gas containing the component to be removed by the cooling means to reduce the moisture contained in the exhaled gas by dew condensation, and the removed exhaled gas is brought into contact with the adsorbent. Remove ingredients. For this reason, unlike a conventional apparatus using silica gel, a filling cylinder for filling a large amount of silica gel is not required, the apparatus can be miniaturized, and the labor for replacing silica gel is eliminated. In addition, since the exhaled air whose moisture has been reduced to the required humidity can be supplied to the adsorbent, etc., the adsorption capacity is reduced due to the condensation water adhering to the adsorbent, and the exhaust gas is discharged due to the condensation water adhering to the piping. There is no hindrance. In addition, it is easy to stably control the moisture removal rate, and it is possible to supply exhaled gas with a stable humidity to the adsorbent and to remove the components to be removed while maintaining the stable adsorption performance of the adsorbent. Become.

In the present invention, when controlling the absolute humidity of the exhaled gas after moisture removal to be within 10 to 25 g / m ³ during the treatment of the exhaled gas, the moisture removing rate is stably controlled. Further, the variation in the humidity of the exhaled gas due to the freshness of the dehumidifying agent such as dehumidification with silica gel can be reduced, and the exhaled gas having a stable humidity can be supplied to the adsorbent. Thereby, it is prevented that the exhaled gas with excessive moisture comes into contact with the adsorbent and the gas contact area of the adsorbent is reduced due to condensed water. Furthermore, it is possible to prevent the condensed water from adhering to the piping in the apparatus and blocking it, thereby preventing the exhaust gas from being discharged. In addition, it is possible to prevent exhaled gas that has been excessively dehumidified and dried too much from coming into contact with the adsorbent and degrading its performance. In this way, it is possible to remove the component to be removed while maintaining stable adsorption performance of the adsorbent.

  In the present invention, when the cooling means uses a Peltier element, it is small in size for maintaining stable moisture removal capability, and the relative humidity of the exhaled gas after treatment can be easily and stably controlled. The exhalation gas having a stable humidity can be supplied to the adsorbent to stably maintain the adsorption performance of the adsorbent and remove the component to be removed. In addition, it is possible to prevent the exhaled gas with excessive moisture from coming into contact with the adsorbent and reducing the gas contact area of the adsorbent due to condensed water. Further, it is possible to prevent the condensed water from adhering to the piping in the apparatus and blocking it. In addition, it is possible to prevent exhaled gas that has been excessively dehumidified and dried too much from coming into contact with the adsorbent and degrading its performance.

  In the present invention, when the exhaled gas is cooled by the cooling means to remove moisture, and the exhaled gas from which moisture has been removed is heated and brought into contact with the adsorbent, sufficient adsorption is possible without reducing the adsorption performance of the adsorbent. The component to be removed can be removed by exerting the ability.

  In the present invention, the exhaled gas contains nitrogen monoxide as a component to be removed, and after removing moisture by the moisture removing means, when contacting the chemical adsorbent to remove nitrogen monoxide, adsorb nitrogen monoxide. Nitrogen monoxide can be removed with sufficient adsorption capacity without deteriorating the adsorption performance of the adsorbent. Moreover, the removal performance of nitric oxide was higher than that of adsorption removal by activated carbon, and it acted effectively.

  FIG. 1 is a diagram showing an embodiment of an expiration gas processing apparatus 1 according to the present invention. In this example, the exhalation gas processing apparatus 1 is an apparatus that processes exhalation gas discharged from the respiration valve 3 of the ventilator 2 and containing nitrogen monoxide (NO) as a component to be removed.

  The exhalation gas processing apparatus 1 includes a moisture removing unit 4 that cools an exhaled gas containing NO as a component to be removed by the cooling unit 10 to condense and remove moisture contained in the exhaled gas, and the moisture removing unit 4. And an adsorption cylinder 5 for removing NO as a component to be removed by bringing the exhaled gas from which moisture has been removed into contact with the adsorbent.

  More specifically, the expiration gas processing apparatus 1 is provided with an outside air mixer 7 to which an introduction tube 6 for introducing expiration gas discharged from the breathing valve 3 of the ventilator 2 is connected. The outside air mixer 7 is provided with an outside air inlet 8 so that the introduced exhaled gas and the outside air introduced from the outside air inlet 8 are mixed in the internal mixing space. The exhaled gas mixed with the outside air in the outside air mixer 7 is introduced into the moisture removing means 4 after the flow rate is measured by the flow rate measuring device 9.

  The moisture removing unit 4 stores the condensed water generated by condensation in the cooling unit 10 and the cooling unit 10 that condenses moisture contained in the expired gas by cooling the expired gas using a Peltier element. A drain tank 13 is provided.

  FIG. 2 is a diagram showing details of the cooling means 10. The cooling means 10 is disposed on the heat absorption side of the Peltier element 14 utilizing the Peltier effect in which heat is transferred from one metal to the other metal when an electric current is passed through a joint of two kinds of metals. The cooling block 11 and the heating block 12 disposed on the heat radiation side of the Peltier element 14 are provided. A radiating fin 15 that is cooled by a cooling fan 16 is attached to the heating block 12.

  The cooling block 11 is provided with a heat exchange pipe 17 into which exhaled gas discharged from the ventilator 2 and passed through the outside air mixer 7 and the flow rate measuring device 9 is introduced. By passing through the heat exchange pipe 17, the exhaled gas is cooled by the heat absorption on the heat absorption side of the Peltier element 14, moisture is condensed and removed, and the humidity is reduced. The condensed water condensed in the heat exchange pipe 17 is stored in the drain tank 13 through the drain pipe 19.

  The heating block 12 is provided with a heat exchange pipe 18 into which exhaled air from which moisture has been removed by the heat exchange pipe 17 of the cooling block 11 is introduced. The exhaled gas passes through the heat exchange pipe 18, receives heat from the heat radiation side of the Peltier element 14, is heated, and is introduced into the adsorption cylinder 5.

  Thus, in this embodiment, the exhalation gas is cooled by the cooling means 10 to remove moisture, and the exhaled gas from which moisture has been removed is heated and brought into contact with the adsorbent. This cooling and heating is performed by using the heat on the cooling side of the cooling means 10 and the heat on the heating side of the cooling means 10 generated when the cold is generated. Specifically, the exhaled air is cooled on the heat absorption side of the Peltier element 14 to remove moisture, and the exhalation is heated using the heat on the heat dissipation side of the Peltier element 14 and introduced into the adsorption cylinder 5. As described above, the heat transfer in the Peltier element 14 is effectively utilized because the heat derived from the heat absorption from the exhaled gas is radiated on the heating block 12 side.

In this example, the adsorption cylinder 5 is formed with a chemical adsorption layer 20 filled with a chemical adsorbent on the introduction side, that is, the upstream side, and a physical adsorption layer 21 filled with a physical adsorbent on the discharge side, that is, the downstream side. Has been. Nitrogen monoxide (NO) is mainly adsorbed and removed by chemical adsorption by the chemical adsorbent, and nitrogen dioxide (NO ₂ ) is mainly adsorbed and removed by physical adsorption by the physical adsorbent. In this way, after exhaled gas containing nitrogen monoxide as a component to be removed is removed by the moisture removing means 4, it is brought into contact with the chemical adsorbent to remove nitrogen monoxide.

  As the chemical adsorbent, for example, “Purafil (registered trademark) Select Chemisorbant” (manufactured by Purafil. Inc.), which is a chemical adsorbent mainly composed of alumina, potassium permanganate, water, or the like, can be suitably used. .

  As said physical adsorption agent, activated carbon etc. can be used, for example.

In the chemical adsorbent described above, nitrogen oxides are adsorbed by an adsorption reaction as shown in the following formulas (1) and (2). As can be seen from these equations, this adsorption reaction requires H ₂ O and exhibits an effective nitrogen oxide removal action in the presence of a certain amount of moisture.
3NO + 2KMnO ₄ + H ₂ O → 3NO ₂ ↑ + 2MnO ₂ ↓ + 2KOH ↓ (1)
3NO ₂ + KMnO ₄ + 2KOH → 3KNO ₃ ↓ + MnO ₂ ↓ + H ₂ O (2)

Therefore, in the exhalation gas processing apparatus 1, while the exhalation gas is being processed, the absolute humidity of the exhalation gas after moisture removal is controlled to be within 10 to 25 g / m ³ , and is controlled to the absolute humidity. The exhalation gas is introduced into the adsorption cylinder 5. In addition, while the exhalation gas is being processed, the relative humidity of the exhalation gas after moisture removal is controlled to be within 20 to 70% RH.

When the absolute humidity introduced into the adsorption cylinder 5 is less than 10 g / m ³ , the moisture necessary for the adsorption reaction is not sufficient as described above, and a sufficient nitrogen oxide removing action with the chemical adsorbent cannot be obtained. Conversely, when the absolute humidity to be introduced into the adsorption column 5 exceeds 25 g / m ^3, there is a fear that condensation in the adsorbent surface and the pipe. In addition, if the relative humidity introduced into the adsorption cylinder 5 is less than 20% RH, the moisture necessary for the adsorption reaction is not sufficient as described above, and sufficient removal of nitrogen oxides with the chemical adsorbent cannot be obtained. . On the other hand, if the absolute humidity introduced into the adsorption cylinder 5 exceeds 70% RH, there is a risk of dew condensation on the adsorbent surface or in the piping.

The exhaled air from which nitrogen oxides such as nitrogen monoxide (NO) and nitrogen dioxide (NO ₂ ) have been removed by the adsorption cylinder 5 is connected to a suction unit (not shown) via a needle valve 22. As described above, by disposing the needle valve 22 on the discharge side, that is, the suction side of the apparatus, it becomes possible to flexibly cope with a change in the flow rate of the ventilator 2 as compared with those using an orifice or the like. And it can prevent that resistance arises with respect to the exhalation-valve 3 of the ventilator 2, and can reduce the risk of causing the malfunction accompanying autopeep etc. with respect to the ventilator 2. FIG.

  By configuring as described above, the expiration gas processing apparatus 1 according to the present embodiment cools the expiration gas containing the component to be removed by the cooling means to reduce the moisture contained in the expiration gas by dew condensation. A component to be removed is removed by bringing the exhaled gas from which moisture has been removed into contact with the adsorbent. For this reason, unlike a conventional apparatus using silica gel, a filling cylinder for filling a large amount of silica gel is not required, the apparatus can be miniaturized, and the labor for replacing silica gel is eliminated. In addition, since the exhaled air whose moisture has been reduced to the required humidity can be supplied to the adsorbent, etc., the adsorption capacity is reduced due to the condensation water adhering to the adsorbent, and the exhaust gas is discharged due to the condensation water adhering to the piping. There is no hindrance. In addition, it is easy to stably control the moisture removal rate, and it is possible to supply exhaled gas with a stable humidity to the adsorbent and to remove the components to be removed while maintaining the stable adsorption performance of the adsorbent. Become.

In the present invention, when controlling the absolute humidity of the exhaled gas after moisture removal to be within 10 to 25 g / m ³ during the treatment of the exhaled gas, the moisture removing rate is stably controlled. Further, the variation in the humidity of the exhaled gas due to the freshness of the dehumidifying agent such as dehumidification with silica gel can be reduced, and the exhaled gas having a stable humidity can be supplied to the adsorbent. Thereby, it is prevented that the exhaled gas with excessive moisture comes into contact with the adsorbent and the gas contact area of the adsorbent is reduced due to condensed water. Furthermore, it is possible to prevent the condensed water from adhering to the piping in the apparatus and blocking it, thereby preventing the exhaust gas from being discharged. In addition, it is possible to prevent exhaled gas that has been excessively dehumidified and dried too much from coming into contact with the adsorbent and degrading its performance. In this way, it is possible to remove the component to be removed while maintaining stable adsorption performance of the adsorbent.

  In the present invention, when the cooling means uses a Peltier element, it is small in size for maintaining stable moisture removal capability, and the relative humidity of the exhaled gas after treatment can be easily and stably controlled. The exhalation gas having a stable humidity can be supplied to the adsorbent to stably maintain the adsorption performance of the adsorbent and remove the component to be removed. In addition, it is possible to prevent the exhaled gas with excessive moisture from coming into contact with the adsorbent and reducing the gas contact area of the adsorbent due to condensed water. Further, it is possible to prevent the condensed water from adhering to the piping in the apparatus and blocking it. In addition, it is possible to prevent exhaled gas that has been excessively dehumidified and dried too much from coming into contact with the adsorbent and degrading its performance.

  In the present invention, when the exhaled gas is cooled by the cooling means to remove moisture, and the exhaled gas from which moisture has been removed is heated and brought into contact with the adsorbent, sufficient adsorption is possible without reducing the adsorption performance of the adsorbent. The component to be removed can be removed by exerting the ability.

  In the present invention, the exhaled gas contains nitrogen monoxide as a component to be removed, and after removing moisture by the moisture removing means, when contacting the chemical adsorbent to remove nitrogen monoxide, adsorb nitrogen monoxide. Nitrogen monoxide can be removed with sufficient adsorption capacity without deteriorating the adsorption performance of the adsorbent. Moreover, the removal performance of nitric oxide was higher than that of adsorption removal by activated carbon, and it acted effectively.

  FIG. 3 is a diagram showing an expiratory gas processing apparatus 1 according to a second embodiment of the present invention.

  In this example, exhaled air that has been cooled by the cooling block 11 of the cooling means 10 and reduced in humidity is directly introduced into the adsorption cylinder 5 without being heated by the heating block 12. Other than that is the same as that of the said 1st Embodiment, and attaches | subjects the same code | symbol to the same part. Also in this example, the same operational effects as those of the first embodiment are obtained.

[Example 1]
First, a dehumidification test was performed by the moisture removing means 4 by the cooling means 10 using the Peltier element 14 corresponding to the present invention.

  FIG. 4A shows an outline of the test apparatus. In the constant temperature and humidity chamber 25 set to 30 ° C. and 70% RH, the cooling means 10 using the Peltier element 14 and the moisture removing means 4 using the drain tank 13 were installed. As the Peltier element 14, four elements having dimensions of 40.0 × 40.0 × 3.45 mm and a cooling capacity Qmax = 77.1 W (Th = 27 ° C.) were used side by side. Moreover, the said cooling means 10 used the thing of the aspect which does not collect | recover the exhaust heat of the Peltier device 14 in the heating block 12, and does not heat the gas after dehumidification similarly to what was shown in FIG.

  A predetermined ratio of outside air (air in the constant temperature and humidity chamber 25 set to 30 ° C. and 70% RH) to the air heated and humidified to 37 ° C. and 100% RH by the heating humidifier 26 with respect to the cooling means 10. ) Were mixed and introduced. The flow rate on the ventilator side was 20 L / min, and the flow rate on the suction side was 30 L / min.

  FIG. 5 shows the results of measuring the gas temperature and relative humidity over time at the outlet of the cooling means 10 at this time. The humidity was measured using a temperature / humidity logger (manufactured by ESPECMIC, model number RS-12).

Thus, in this Example 1, the humidity change after dehumidification is hardly seen, the temperature of the exhaust gas after dehumidification is constant at about 31-32 ° C., and the relative humidity is about 52-59% RH. It can be seen that the change is in the range. The absolute humidity of the exhaust gas after the dehumidifying process has shifted within a range of about 16 to 20 g / m ³ .

  Further, from the results of Example 1, since the gas after moisture absorption is not too dry and contains stable moisture, the adsorption performance of a chemical adsorbent (for example, Purafyl Select Chemisorbant) used for NO adsorption detoxification is shown. It turns out that it does not reduce.

[Example 2]
Next, in the test apparatus shown in FIG. 4 (A), the exhaust heat of the Peltier element 14 is recovered in the heating block 12 as the cooling means 10 shown in FIG. The embodiment was used.

FIG. 6 shows the results of measuring the gas temperature and relative humidity over time at the outlet of the cooling means 10 at this time. Thus, in this Example 2, the humidity change after dehumidification is hardly seen, the temperature of the exhaust gas after dehumidification is constant at about 42 ° C., and the relative humidity is within about 33 to 36% RH. It can be seen that the change is in the range of. The absolute humidity of the exhaust gas after the dehumidifying process has changed within a range of about 17 to 20 g / m ³ . Thus, it can be seen that the relative humidity of the gas after dehumidification is about 30%, and 50% (temperature 30 ° C), which is the ideal relative humidity when considering the prevention of dew condensation in the piping, is sufficient. It can be seen that it has been cleared.

  Also, from the results of Example 2, the gas after moisture absorption is not too dry and contains stable moisture. Therefore, the adsorption performance of a chemical adsorbent (for example, Purafyl Select Chemisorbant) used for NO adsorption detoxification. It can be seen that it does not decrease.

[Comparative Example]
Next, a dehumidification test using silica gel was performed.

  FIG. 4B shows an outline of the test apparatus. A dehumidifying cylinder 27 filled with silica gel as a dehumidifying agent was placed in a constant temperature and humidity chamber 25 set to 30 ° C. and 70% RH. The silica gel used had a blue color derived from cobalt chloride, and 3 kg of particles having a granular or spherical particle shape and a particle diameter of 3.4 mm or more were used. The column size of the dehumidifying cylinder 27 at this time was φ100 mm × (H) 600 mm.

  With respect to the dehumidifying cylinder 27, the air is heated and humidified to 37 ° C. and 100% RH in the heating / humidifier 26, and a predetermined ratio of outside air (air in the constant temperature and humidity chamber 25 set to 30 ° C. and 70% RH). ) Were mixed and introduced. The flow rate on the inlet side was 20 L / min, and the flow rate on the outlet side was 30 L / min.

  FIG. 7 shows the results of measuring the temperature and relative humidity of the gas at the outlet of the dehumidifying cylinder 27 over time, and Table 2 was required to dehumidify to 50% RH under the above conditions with 3 kg of silica gel. The result of measuring time is shown. The humidity was measured using a temperature / humidity logger (manufactured by ESPECMIC, model number RS-12).

  From this result, it can be seen that the dehumidification with 3 kg of silica gel reaches the saturation of the silica gel in about 6 hours and needs to be replaced with a new silica gel.

  In addition, it can be seen that the gas after moisture absorption becomes excessively dry at the initial stage of dehumidification, and as a result, the adsorption performance of a chemical adsorbent (for example, Purafyl Select Chemisorbant) used for NO adsorption detoxification may be reduced.

Example 3
Exhalation gas NOx adsorption removal treatment was performed by the exhalation gas treatment apparatus 1 shown in FIGS. 1 and 3. The process by the apparatus of FIG. 1 is an example in which the dehumidified gas is heated using the exhaust heat of the Peltier element 14 and introduced into the adsorption cylinder 5. The process by the apparatus of FIG. 3 does not use the exhaust heat. In this example, exhaled gas after dehumidification is directly introduced into the adsorption cylinder 5 without being heated.

As the NO adsorbent, a chemical adsorbent (Purafil Select Cellisorbant) was used as described above. As the NO ₂ physical adsorbent, activated carbon (Kuraray Coal 2GGK5022440, particle size: 95% or more of particles having a particle size of 1.70 to 2.80 mm, manufactured by Kuraray Chemical Co., Ltd.) was used. As the needle valve 22, model number 24121-SS-1 / 4 manufactured by Cofrock Co., Ltd. was used.

The operation of the exhalation gas treatment apparatus 1 was performed under the following conditions.
Ventilator flow rate: 20 L / min
Suction flow rate: 30L / min
NO concentration: 20ppm
Filling ratio of chemical adsorbent and physical adsorbent: volume ratio 2: 1 (500 g: 120 g)

  In addition, the filling ratio of the chemical adsorbent and the physical adsorbent was determined from the measurement results in Table 3 below, in which the removal efficiency was measured by changing the filling ratio.

The apparatus is operated under the above conditions to perform NOx adsorption and detoxification treatment. The temperature and humidity of the gas after dehumidification and the time until the NO concentration at the outlet of the adsorption cylinder 5 gradually increases to reach 0.3 ppm, Was measured. The results are shown in Table 3 below. The measurement of NOx was carried out at chemiluminescence by _NOx-NO 2 -NO automatic analyzer M10DEL42E (manufactured by Thermo Electron Corporation). The measurement conditions at this time are as follows.
Measurement range: 0 to 5000 ppm (full scale can be set)
Response time (0 to 90% FS): 10 seconds Sample flow rate: about 0.25 L / min

  Thus, for example, if the allowable exhaust concentration of NO is set to 0.3 ppm, it is possible to operate until the detoxification capacity is saturated when the dehumidified gas is heated and brought into contact with the adsorbent. Is l. It turns out that it extends 6 times. That is, in the example in which the gas after dehumidification is heated and introduced into the adsorption cylinder 5, the time until it reaches 0.3 ppm is longer, and the life of the chemical adsorbent becomes longer. Actually, since the allowable concentration of NO may be higher, it is effective to heat the dehumidified gas and bring it into contact with the adsorbent.

  In the above-described embodiments and examples, the cooling means 10 using the Peltier element 14 is exemplified, but the invention is not limited to this, and various types can be used as long as moisture can be removed by condensation due to cooling. Can be used. Further, the chemical adsorbent and the physical adsorbent are not limited to those exemplified, and various types can be used.

It is a schematic block diagram of the processing apparatus of the expiration gas of 1st Embodiment of this invention. It is a schematic block diagram of a cooling means. It is a schematic block diagram of the processing apparatus of the expiration gas of 2nd Embodiment of this invention. It is a figure which shows schematic structure of the test apparatus of a dehumidification test. Results of dehumidification test with cooling means using Peltier element (no heating after dehumidification). The dehumidification test result in the cooling means using a Peltier device (there is heating after dehumidification). The dehumidification test result in the cooling means using silica gel.

Explanation of symbols

1: Exhalation gas processing device 2: Respirator 3: Respiration valve 4: Moisture removal means 5: Adsorption cylinder 6: Introduction tube 7: Outside air mixer 8: Outside air introduction port 9: Flow rate measuring device 10: Cooling means 11: Cooling block 12: Heating block 13: Drain tank 14: Peltier element 15: Radiation fin 16: Cooling fan 17: Heat exchange pipe 18: Heat exchange pipe 19: Drain pipe 20: Chemical adsorption layer 21: Physical adsorption layer 22: Needle valve 25: Constant temperature and humidity chamber 26: Heating humidifier 27: Dehumidifying cylinder

Claims (5)

  The apparatus includes a water removing unit that cools the exhaled gas containing the component to be removed by the cooling unit to condense and remove the moisture contained in the exhaled gas, and the exhaled gas from which the water has been removed by the moisture removing unit is brought into contact with the adsorbent. An apparatus for treating exhaled gas, wherein a component to be removed is removed. The expiration gas processing apparatus according to claim 1, wherein the absolute humidity of the expiration gas after moisture removal is controlled to be within 10 to 25 g / m ³ during the expiration gas processing.   The expiration gas processing apparatus according to claim 1 or 2, wherein the cooling means uses a Peltier element.   The exhalation gas processing apparatus according to any one of claims 1 to 3, wherein the exhalation gas is cooled by the cooling means to remove moisture, and the exhalation gas from which moisture has been removed is heated and brought into contact with the adsorbent.   The exhaled gas contains nitric oxide as a component to be removed, and after removing moisture by the moisture removing means, the exhaled gas is brought into contact with a chemical adsorbent to remove nitric oxide. Exhalation gas processing equipment.

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