JP2006191973A - Thermally conductive member, reaction vessel and reaction method of carbon dioxide absorbent - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve a reaction efficiency by suppressing the reactivity of a stored carbon dioxide absorbent from being lowered locally. <P>SOLUTION: The thermally conductive member 12 is mounted inside a vessel body 11 storing the carbon dioxide absorbent 10 and provided with an inflow port 13 where a gas containing carbon dioxide flows in and an outflow port 14 where the gas that has passed through the carbon dioxide absorbent 10 flows out. The heat conduction member 12 is arranged along the flowing direction of the gas passing through the carbon dioxide absorbent 10 so as to heat the other part of the carbon dioxide absorbent 10 by the heat of the heat generation part of the carbon dioxide absorbent 10. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a heat conducting member, a reaction container, and a method for reacting a carbon dioxide absorbent that are provided in a reaction container that is disposed on a circulation path of a ventilator, for example, and contains a carbon dioxide absorbent.

  2. Description of the Related Art Conventionally, for example, in a ventilator such as a circulatory gas anesthesia machine, a canister disposed on a circulation path is known for absorbing and removing carbon dioxide contained in a patient's breath.

  In general, this type of canister contains a predetermined amount of carbon dioxide absorbent such as particles and particles, and has an inlet through which a gas flows from the circulation path, and a gas that has passed the carbon dioxide absorbent through the circulation path. And a plastic container provided with an outlet.

  In such a canister, the gas flowing in from the inlet passes through the carbon dioxide absorbent housed inside, so that the carbon dioxide contained in the gas and the carbon dioxide absorbent cause an exothermic chemical reaction. The carbon dioxide contained in the gas is absorbed to generate water vapor, and the treated gas from which the carbon dioxide has been removed flows out from the outlet.

  In the circulatory system used clinically, when the concentration of carbon dioxide in the treated gas that has passed through the canister, that is, when the partial pressure of carbon dioxide is 5 mmHg or more, the carbon dioxide absorbent absorbs carbon dioxide. It is judged that the absorption is not sufficiently performed, and the canister in which the carbon dioxide absorbent is not completely consumed is removed from the circulation system, and a predetermined amount of carbon dioxide absorbent remaining in the canister is newly added. It has been replaced with a carbon dioxide absorbent.

  However, in a canister that has not sufficiently absorbed, even if the carbon dioxide partial pressure of the treated gas that has passed through the canister increases, the carbon dioxide absorbent that has not been consumed remains and can react. Nevertheless, the carbon dioxide absorbent is wasted.

  Although there is a carbon dioxide absorbent that can react in this way, the carbon dioxide absorption capacity is reduced because of the lack of reactivity at each part of the carbon dioxide absorbent contained in the container. This is due to a uniform phenomenon (hereinafter referred to as channeling).

  In the conventional concept of channeling, when the gas is circulated in a state where the carbon dioxide absorbent is filled in the cylindrical storage body, the flow resistance of the carbon dioxide absorbent in the central portion housed in the storage body In addition, the flow resistance of the carbon dioxide absorbent in the outer peripheral portion contacting the inner peripheral surface of the container is relatively small, and the inner peripheral surface of the container is compared with the gas passing through the carbon dioxide absorbent in the central portion. It has been considered that the gas flow rate becomes non-uniform depending on the radial position of the canister due to an increase in the flow rate of the gas passing through the carbon dioxide absorbent in the outer peripheral side portion in contact. In other words, channeling is caused by the non-uniformity of the gap between the porous particles forming the carbon dioxide absorbent in the container, and the flow of the gas passing through the carbon dioxide absorbent is not flat on a plane perpendicular to the flow direction. This is considered to be uniform.

  Therefore, it is required to efficiently react the carbon dioxide absorbent in the container, and various measures for improving the structure of the canister and the reaction characteristics of the carbon dioxide absorbent itself as a countermeasure to improve channeling. Has been.

  As a canister structure, in conventional canisters, channeling is caused by non-uniformity of the gas flow through the carbon dioxide absorbent due to non-uniformity of the gap between the porous particles forming the carbon dioxide absorbent in the container. In accordance with the concept of being caused, a configuration has been proposed in which a protruding wall that prevents gas flowing along the inner peripheral surface is provided on the inner peripheral surface of the container corresponding to the carbon dioxide absorbent in the outer peripheral side portion (for example, Non-patent document 1). According to this structure, the flow rate of the gas which passes the carbon dioxide absorbent of the outer side part contact | abutted to the internal peripheral surface of a container is suppressed by the protrusion wall of an internal peripheral surface, and the outer peripheral side contact | abutted to the internal peripheral surface of a container It is possible to suppress non-uniformity in the flow rates of the part and the gas passing through the carbon dioxide absorbent in the central part.

  Further, as another conventional canister, in order to improve the non-uniformity of the gas flow rate generated in the container, a substantially conical shape in which the central portion protrudes toward the inlet side on the outlet side of the container. The structure which arrange | positions the gas flow control member which has this protrusion part is proposed. According to this conventional canister, it is possible to increase the flow rate through the carbon dioxide absorbent in the central portion.

In addition, as a reaction characteristic of the carbon dioxide absorbent itself, in order to improve the non-uniformity of the gap between the porous particles and to make the flow resistance uniform at each position of the carbon dioxide absorbent, the carbon dioxide absorbent is used. The shape, size, composition, etc. of each individual grain are devised. However, conventional measures have not led to effective improvement of channeling.
ANESTHESIA EQUIPMENT principles and applications, Chapter 4, Anesthesia breathing systems, p.97-99, Publisher: Williams & Wilkins, 4th edition (1999/01/15), ISBN: 0683304879

  By the way, generally in a canister, the carbon dioxide absorbent accommodated in the inside causes a chemical reaction from the upstream end of the carbon dioxide absorbent with respect to the flow direction of the gas passing through the carbon dioxide absorbent. As the reaction progresses, the reaction site of the carbon dioxide absorbent sequentially moves from the upstream end along the flow direction, and finally the reaction site reaches the downstream end of the carbon dioxide absorbent. As described above, in the carbon dioxide absorbent in the canister, the temperature at the local reaction site is increased, the temperature is always lowered at the downstream side of the reaction site, and a temperature difference occurs between the reaction site and the unreacted site.

  In addition, the carbon dioxide absorbent accommodated in the conventional canister is such that the carbon dioxide absorbent in the outer peripheral side contacting the inner peripheral surface of the container is cooled by the outside air, and is more than the carbon dioxide absorbent in the central side part. Since temperature falls, the temperature difference by each site | part of a carbon dioxide absorbent is caused.

  Then, the water vapor generated by the chemical reaction flows in the carbon dioxide absorbent together with the gas, and then, as the temperature decreases, the carbon dioxide absorbent in the unreacted portion of the carbon dioxide absorbent, particularly the downstream portion, and Condensation is generated in the carbon dioxide absorbent in the outer peripheral portion that is in contact with the inner peripheral surface of the container, and the water content of the carbon dioxide absorbent in each portion is excessively increased. Carbon dioxide absorbent with excessively increased water content adheres to the surface and internal micropores of the porous particles, reducing the reactivity by blocking the micropores or adhering to the surface in the form of a film. I will let you.

  For this reason, the gas passing through the carbon dioxide absorbent in the downstream portion where the water content has increased excessively locally and in the outer peripheral portion in contact with the inner peripheral surface of the container is reduced by the decrease in the reactivity of the portion. Of carbon dioxide absorbed in the treated gas even though unconsumed carbon dioxide absorbent remains in the carbon dioxide absorbent in the central part of the container. Will increase.

  Therefore, the present invention suppresses the occurrence of a temperature difference in each part of the stored carbon dioxide absorbent, prevents the local reactivity of the carbon dioxide absorbent from decreasing, and improves the reaction efficiency of the carbon dioxide absorbent. It is an object of the present invention to provide a heat conducting member that can be achieved, a reaction vessel equipped with the heat conducting member, and a method for reacting a carbon dioxide absorbent.

  In order to achieve the above-described object, the heat conducting member according to the present invention contains a carbon dioxide absorbent, an inlet into which a gas containing carbon dioxide flows, and an outlet from which the gas that has passed through the carbon dioxide absorbent flows out. A heat conducting member mounted in a container having a gas passage through the carbon dioxide absorbent so that the other part of the carbon dioxide absorbent is heated by the heat of the heat producing part of the carbon dioxide absorbent. Arranged along the flow direction.

  According to the heat conducting member configured as described above, when the carbon dioxide absorbent and the gas chemically react with each other, the heat of the heat generation portion of the carbon dioxide absorbent is not generated by the carbon dioxide absorbent. By conducting heat to this part, the occurrence of a temperature difference at each part of the carbon dioxide absorbent in the container is suppressed, and the temperature distribution at each part is made uniform. For this reason, the carbon dioxide absorbent in the container can suppress the moisture content of the carbon dioxide absorbent from increasing non-uniformly and excessively due to dew condensation caused by the generated water vapor, and the reactivity at each site can be made uniform. The reaction efficiency of the carbon dioxide absorbent is improved. Moreover, this heat conduction member is arrange | positioned along a flow direction, and gas passes the carbon dioxide absorbent in a container favorably, without the flow of the gas which passes a carbon dioxide absorbent being prevented.

  Therefore, in the present invention, as described above, channeling is considered to be caused by a non-uniform and excessive increase in moisture content locally due to the temperature difference of each part of the carbon dioxide absorbent. The main purpose is to suppress the temperature difference.

Further, the reaction container according to the present invention contains a carbon dioxide absorbent, a container having an inlet into which a gas containing carbon dioxide flows in, and an outlet from which the gas that has passed through the carbon dioxide absorbent flows out,
A heat conduction member disposed in the container along the flow direction of the gas passing through the carbon dioxide absorbent and for heating other parts of the carbon dioxide absorbent with heat of the heat generation part of the carbon dioxide absorbent; Prepare.

  According to the reaction container according to the present invention configured as described above, when the carbon dioxide absorbent and the gas chemically react with each other, the heat conduction member causes the heat of the heat generation portion of the carbon dioxide absorbent to be generated by the carbon dioxide absorbent. By conducting heat to other parts where no heat is generated, it is possible to suppress a temperature difference from occurring in each part of the carbon dioxide absorbent in the container, and to make the temperature distribution in each part uniform. For this reason, the carbon dioxide absorbent in the container can suppress the moisture content of the carbon dioxide absorbent from increasing non-uniformly and excessively due to dew condensation caused by the generated water vapor, and the reactivity at each site can be made uniform. The reaction efficiency of the carbon dioxide absorbent is improved. In addition, the reaction container is arranged in the flow direction so that the gas flowing through the carbon dioxide absorbent is not hindered, and the gas in the container is improved. pass.

  Moreover, it is preferable that the heat conductive member with which the reaction container which concerns on this invention is provided is arrange | positioned so that the upstream edge part and downstream edge part of a carbon dioxide absorber may be covered with respect to the flow direction of gas. Thereby, the temperature difference which arises in each site | part of the flow direction of the gas in the carbon dioxide absorbent in a container is suppressed small.

  Moreover, it is preferable that the heat conductive member with which the reaction container which concerns on this invention is provided is arrange | positioned so that it may extend from the center side vicinity of a container to the surrounding surface side vicinity with respect to the direction orthogonal to the flow direction of gas. Thereby, the temperature difference which arises in each site | part of the center side vicinity and outer peripheral side vicinity in the carbon dioxide absorber in a container is suppressed small.

  In the reaction container according to the present invention, a heat conducting member may be connected to the container. As a result, heat transmitted through the heat conducting member is transferred to the container, thereby suppressing a temperature difference generated between the carbon dioxide absorbent in the outer peripheral portion and the carbon dioxide absorbent in the central portion contacting the inner peripheral surface of the container. It is done.

  Moreover, the reaction container which concerns on this invention may be provided with the heat insulation means which heat-insulates with external air in the outer peripheral part of a container. Since the heat insulating means prevents the container from taking heat away from the outside air, it is possible to suppress the temperature of the carbon dioxide absorbent in the outer peripheral portion contacting the inner peripheral surface of the container from being lowered, and the central portion. The difference in temperature between the carbon dioxide absorbent and the carbon dioxide absorbent at the outer peripheral side portion in contact with the inner peripheral surface of the container is suppressed.

Further, another reaction container according to the present invention contains a carbon dioxide absorbent, and has an inner housing having an inlet into which a gas containing carbon dioxide flows and an outlet from which a gas that has passed through the carbon dioxide absorbent flows out. Body,
The inner container is housed inside, and an outer container is provided that allows the gas flowing out from the outlet to flow along the outer periphery of the inner container.

  According to the reaction container according to the present invention configured as described above, when the carbon dioxide absorbent and the gas undergo a chemical reaction, the heat of the gas that has passed through the carbon dioxide absorbent in the inner container is absorbed by the inner container. The carbon dioxide absorbent is heated through the inner container. For this reason, the temperature difference which arises in each site | part of the carbon dioxide absorber in an inner side container is suppressed, and the uniformity of the reactivity in each site | part of a carbon dioxide absorber is achieved. Moreover, according to this reaction container, since an inner side container is covered with an outer side container, it is also prevented that the outer peripheral side site | part of the carbon dioxide absorbent in an inner side container is cooled with external air.

  In addition, the other reaction container according to the present invention, in the inner container, along the flow direction of the gas passing through the carbon dioxide absorbent, other heat of the carbon dioxide absorbent by heat of the carbon dioxide absorbent, A heat conducting member for heating the part may be provided. According to this, when the carbon dioxide absorbent and the gas chemically react, the heat of the exothermic part of the carbon dioxide absorbent is thermally conducted to other parts of the carbon dioxide absorbent, The temperature difference generated at each part of the carbon dioxide absorbent is further suppressed satisfactorily.

  Further, the carbon dioxide absorbent reaction method according to the present invention is a method in which a gas containing carbon dioxide is passed through a carbon dioxide absorbent housed in a container to cause a chemical reaction between the gas and the carbon dioxide absorbent. The carbon absorbent reaction method is characterized in that the other part of the carbon dioxide absorbent is heated by the heat of the heat generating part of the carbon dioxide absorbent by the heat conducting member provided in the container.

  In another carbon dioxide absorbent reaction method according to the present invention, a gas containing carbon dioxide is allowed to pass through a carbon dioxide absorbent housed in the container to cause a chemical reaction between the gas and the carbon dioxide absorbent. In the carbon dioxide absorbent reaction method, the gas that has passed through the carbon dioxide absorbent is caused to flow along the outer periphery of the container, and the heat of the gas heats the carbon dioxide absorbent through the container. Features.

  As described above, according to the present invention, since a temperature difference is suppressed from occurring in each part of the stored carbon dioxide absorbent, a decrease in local reactivity of the carbon dioxide absorbent is prevented, and carbon dioxide The reaction efficiency of the absorbent can be improved.

  Hereinafter, specific embodiments of the present invention will be described with reference to the drawings.

  As an example of the reaction container according to the present invention, a canister disposed in the circulatory system of an anesthesia machine which is a ventilator will be described. The canister of this embodiment is used, for example, to absorb carbon dioxide contained in a mixture by a particulate carbon dioxide absorbent on a circulation path for circulating a mixed gas of air and anesthetic gas.

Further, the carbon dioxide absorbent accommodated in the canister of the present embodiment contains calcium hydroxide (Ca (OH) ₂ ) as a main component and contains sodium hydroxide (NaOH) or potassium hydroxide (KOH). The water content is about 15 to 20%. As the carbon dioxide absorbent used for medical purposes, soda lime whose main component is calcium hydroxide (Ca (OH) ₂ ) or barium lime whose main component is barium hydroxide Ba (OH) ₂ is used. Besides, lithium hydroxide Li (OH) ₂ is used except for medical use. In any carbon dioxide absorbent, as indicated by the chemical formula, the carbon dioxide absorbent requires moisture in the process of absorbing carbon dioxide, and the dry dioxide absorbent becomes difficult to absorb carbon dioxide. Conversely, carbon dioxide absorbents having excessive moisture content are less reactive. For example, with soda lime, it has been reported that the absorption capacity of carbon dioxide is reduced when water is added to a moisture content of 25%. For this reason, it is generally considered that the water content of soda lime is well maintained in the range of 15 to 20%.

(First embodiment)
As shown in FIG. 1, the canister 1 according to the present embodiment includes a housing 11 that houses a carbon dioxide absorbent 10 therein, and other portions by heat of a heat generating portion of the carbon dioxide absorbent 10 in the housing 11. And a heat conductive member 12 for heating.

  The container 11 is formed in a bottomed cylindrical shape by a resin material such as plastic. In the container 11, a gap is secured between the gas introduction pipe 16 having an inlet 13 into which exhaled air, that is, carbon dioxide-containing gas flows from the circulation system, and the carbon dioxide absorbent 10 and the bottom surface of the container 11. Thus, a disk-shaped screen member 17 that supports the carbon dioxide absorbent 10 is provided.

  The gas introduction pipe 16 is provided with a mesh-like filter 18 at the inlet 13 on one end side, and the other end side is fixed to the center of the screen member 17. In the gas introduction pipe 16, the outer peripheral portion of the screen member 17 is engaged with the inner peripheral portion on the bottom surface side of the container 11 so as to open a space between the screen member 17 and the bottom surface of the container 11. . The container 11 also has an outlet 14 through which the gas introduced by the gas introduction pipe 16 flows out through the carbon dioxide absorbent 10. The screen member 17 is formed in a mesh shape having air permeability.

   The canister 1 of the present embodiment may be a conventional canister as the container 11, the gas introduction pipe 16, etc., except for the heat conducting member 12. Therefore, the canister 1 can be configured simply by mounting the heat conducting member 12 in the conventional canister housing.

  The gas introduction pipe 16 may be formed of a metal material having a relatively high thermal conductivity such as aluminum. As a result, the heat of the carbon dioxide absorbent 10 at the central portion in the container 11 is transmitted well to other portions in the gas flow direction, so that the temperature distribution at each portion of the carbon dioxide absorbent 10 is more uniform. This is preferable.

  As shown in FIG. 2, the heat conducting member 12 is formed in a cylindrical shape in which a flat plate made of a metal material having a relatively high thermal conductivity such as aluminum or copper is curved in a spiral shape. In addition, a coating film is formed on the surface of the heat conducting member 12 by, for example, electroless nickel plating, and corrosion due to gas, water vapor, or alkaline carbon dioxide absorbent is prevented.

  And the heat conductive member 12 is arrange | positioned so that the flow of gas may not be disturbed in the inside of the container 11 along the flow direction of the gas which passes the carbon dioxide absorbent 10. FIG. This heat conducting member 12 has both ends parallel to the flow direction of the gas passing through the carbon dioxide absorbent 10 in the container 11, and the upstream end and the downstream of the carbon dioxide absorbent 10 accommodated in the container 11. It arrange | positions so that a side edge part may be spanned. Thereby, the temperature difference which arises in each site | part of the gas flow direction in the carbon dioxide absorbent 10 in the container 11 is suppressed small.

  Further, the heat conducting member 12 is disposed so as to extend in the vicinity of the center side and the outer peripheral side of the container 11 with respect to the direction orthogonal to the flow direction of the gas passing through the carbon dioxide absorbent 10. Thereby, the temperature difference which arises in each site | part of the center side vicinity in the carbon dioxide absorbent 10 in the container 11 and the outer peripheral side vicinity is suppressed small. The heat conducting member 12 is preferably formed of a metal material having a relatively high thermal conductivity, but the other part of the carbon dioxide absorbent 10 is heated by the heat of the heat generating part of the carbon dioxide absorbent 10. If possible, for example, even if formed of a resin material such as plastic, a ceramic material, a glass material, etc., the thermal conductivity is lower than that of a configuration made of a metal material, but the effects described later are the same. Is obtained.

  And the canister 1 is filled with the carbon dioxide absorbent 10 so that the heat conducting member 12 in the container 11 is buried in the carbon dioxide absorbent 10, and is installed in a part of the piping constituting the circulation path of the ventilator. It is detachably mounted on the provided canister mounting portion. The canister 1 is mounted on the canister mounting portion so that the inlet 13 and the outlet 14 are partitioned.

  Regarding the canister 1 configured as described above, a state in which the canister 1 is mounted on the canister mounting portion, absorbs carbon dioxide from the gas flowing in from the inlet 13 and flows out from the outlet 14 will be described.

  In the canister 1, the gas introduced from the inlet 13 of the gas introduction pipe 16 passes through the space between the screen member 17 and the bottom surface of the container 11, and is upstream of the carbon dioxide absorbent 10 placed on the screen member 17. Entering from the end (bottom side), the gas and the carbon dioxide absorbent 10 start an exothermic chemical reaction.

  The carbon dioxide absorbent 10 in the container 11 is heated by the heat conducting member 12 in contact with the heat generating portion of the carbon dioxide absorbent 10 so that the heat of the heat generating portion of the carbon dioxide absorbent 10 is changed in the gas flow direction. It is transmitted to each part of the carbon absorbent 10 and each part of the carbon dioxide absorbent 10 in the radial direction of the container 11, and the unreacted part at the downstream end of the carbon dioxide absorbent 10 is heated.

  For this reason, in the carbon dioxide absorbent 10 in the container 11, the temperature range generated between the heat generation part and the downstream part is suppressed, and the temperature distribution in each part in the gas flow direction is made uniform. Therefore, the carbon dioxide absorbent 10 in the container 11 avoids an excessive increase in the moisture content of the downstream portion due to dew condensation caused by the generated water vapor, and the reaction at each portion in the gas flow direction. Uniformity is achieved.

  As described above, according to the canister 1 of the present embodiment, the heat conducting member 12 is disposed in the container 11 along the flow direction of the gas passing through the carbon dioxide absorbent 10. The temperature distribution of each part in the flow direction of the gas of the carbon dioxide absorbent 10 can be made uniform. Therefore, the canister 1 can prevent a decrease in reactivity at the downstream side portion of the carbon dioxide absorbent 10 and improve the reaction efficiency in the gas flow direction in the carbon dioxide absorbent 10.

  And according to this canister 1, when soda lime which has calcium hydroxide as a main component is used as the carbon dioxide absorbent 10, compared with the conventional canister, reaction efficiency can be improved about 20%. Therefore, according to the canister 1, by fully exhibiting the reactivity of the carbon dioxide absorbent 10, the usable time is extended and the reactive carbon dioxide absorbent 10 is prevented from being wasted. As a result, the cost during use is reduced.

  Although not shown, depending on the external temperature of the usage environment, the outer periphery of the container 11 may be provided with a heat insulating material that is a heat insulating means for heat insulating from the outside air, a heat insulating coating film, or the like. As a result, the cooling of the outer peripheral portion of the carbon dioxide absorbent 10 in the container 11 is suppressed, and the uneven temperature distribution in each portion can be further improved.

  Therefore, the canister 1 according to the present invention is a conventional channeling method in which the flow of gas passing through the carbon dioxide absorbent is caused by nonuniformity due to the nonuniformity of the gap between the porous particles forming the carbon dioxide absorbent. It is based on a new channeling concept that is different from the concept.

  In the canister 1 of the present embodiment, the gas introduction pipe 16 is provided in the container 11, but the gas is not provided from the gas inlet pipe to the other end side of the cylindrical container. The same effect can be obtained and the configuration can be simplified.

  Moreover, although the heat conducting member 12 provided in the canister 1 of the present embodiment is formed in a cylindrical shape obtained by curving the flat plate described above, both ends in the gas flow direction are provided from the upstream side to the downstream side. As long as the heat of the reaction site of the carbon dioxide absorbent 10 is transferred well to other parts of the carbon dioxide absorbent 10 and does not obstruct the gas flow, it is formed into other shapes as necessary. Also good.

  Examples of other heat conducting members are shown in FIGS. As shown in FIG. 3A, the heat conducting member 22a is formed by combining a plurality of heat conducting plates in a lattice shape, and a cross section perpendicular to the gas flow direction is formed in a lattice shape. As shown in FIG. 3B, the heat conducting member 22 b has a plurality of flat plates arranged with a predetermined interval with respect to the radial direction in the housing 11. As shown in FIG. 3C, the heat conducting member 22c has a plurality of flat plates arranged radially and joined at one end, and a cross section perpendicular to the gas flow direction is formed radially. As shown in FIG. 3 (d), the heat conducting member 22 d is arranged with its length direction parallel to the flow direction of the gas passing through the carbon dioxide absorbent 10, and is predetermined with respect to the radial direction in the container 11. It has a plurality of cylindrical bars arranged at intervals. The canister 1 according to the present invention can obtain the above-described effects in the same manner by including these heat conducting members 22a to 22b.

(Second Embodiment)
Next, a canister according to a second embodiment will be described with reference to the drawings. The canister of the second embodiment does not suppress the temperature range in the gas flow direction, but suppresses the temperature range by heating the carbon dioxide absorbent in the outer peripheral portion that contacts the inner peripheral surface of the container. Is different from the canister 1 described above.

  As shown in FIG. 4, the canister 2 of the present embodiment includes an inner container 23 that accommodates the carbon dioxide absorbent 10 and an outer container 24 that accommodates the inner container 23 therein.

  The inner container 23 is formed in a substantially cylindrical shape. An inlet 26 through which gas flows is provided at one end side, and an outlet 27 through which the gas that has passed through the carbon dioxide absorbent 10 flows out at the other end. Is provided. The inner container 23 is provided with a filter 28 at the inlet 26, and the outlet 27 is fixed to the center of the screen member 29. The inner container 23 has a space between the screen member 29 and the bottom surface of the outer container 24, and the outer periphery of the screen member 29 is engaged with the inner periphery of the outer container 24.

  The outer container 24 is formed in a bottomed cylindrical shape, and is sized so as to open a predetermined gap between the outer container 24 and the outer peripheral surface of the inner container 23. It flows along the entire circumference of the outer periphery of the container 23. The opening of the outer container 24 constitutes an outlet 30 through which the gas that has flowed along the outer periphery of the inner container 23 flows out into the circulation path.

  The canister 2 is mounted on a canister mounting portion provided on the circulation path of the ventilator, thereby partitioning the inlet 27 of the inner container 23 and the outlet 30 of the outer container 24.

  In the canister 2 configured as described above, when the carbon dioxide absorbent 10 and the gas undergo a chemical reaction, the gas that has passed through the carbon dioxide absorbent 10 in the inner container 23 is placed on the outer periphery of the inner container 23. By flowing along, the heat of the gas is transmitted to the inner container 23, and the carbon dioxide absorbent 10 at the outer peripheral side contacting the inner peripheral surface of the inner container 23 is heated through the inner container 23. Is done. For this reason, the temperature difference which arises in each site | part of the carbon dioxide absorbent 10 in the inner side container 23 is suppressed. Moreover, in this canister 2, since the outer peripheral part of the inner side container 23 is covered with the outer side container 24, it can prevent that the outer peripheral side part of the carbon dioxide absorbent 10 in the inner side container 23 is cooled by external air. Is done.

  According to the canister 2 described above, by providing the outer container 24 that causes the gas that has passed through the carbon dioxide absorbent 10 to flow along the outer peripheral portion of the inner container 23, the carbon dioxide absorbent 10 can be warmed. Since the outer peripheral portion of the carbon dioxide absorbent 10 in the inner container 23 is heated by the heat of the gas, the carbon dioxide absorbent 10 in the outer peripheral portion and the carbon dioxide absorbent 10 in the central portion are generated. A temperature range is suppressed and the temperature distribution of each part between an outer peripheral side site | part and a center side site | part can be equalize | homogenized. Therefore, the canister 2 is configured so that the temperature distribution of each part between the outer peripheral side part and the central side part of the carbon dioxide absorbent 10 in the inner container 23 is equalized, whereby the inner peripheral surface of the inner container 23 is obtained. It is possible to prevent an excessive increase in the moisture content of the carbon dioxide absorbent 10 at the outer peripheral side portion that is in contact with the water, thereby improving the reaction efficiency.

(Third embodiment)
A canister according to a third embodiment will be described with reference to the drawings. The canister of the third embodiment includes a temperature difference between the carbon dioxide absorbent 10 at the outer peripheral side portion and the carbon dioxide absorbent 10 at the central side portion that contacts the inner peripheral surface of the container, and a temperature range in the gas flow direction. This is different from the above-described canisters 1 and 2 in that each of the above is suppressed. In the present embodiment, the same members as those in the above-described embodiment are denoted by the same reference numerals and description thereof is omitted.

  As shown in FIG. 5, the canister 3 of the present embodiment includes a housing 31 that houses the carbon dioxide absorbent 10 and a heat conducting member 32 that is integrally connected to the inner periphery of the housing 31. Yes.

  The container 31 is formed in a substantially bottomed cylindrical shape with a material having a relatively high thermal conductivity such as aluminum, for example, and the gas introduced by the gas introduction pipe 16 flows out through the carbon dioxide absorbent 10. An outlet 34 is provided.

  The heat conducting member 32 is composed of a plurality of heat conducting plates made of a material having a relatively high thermal conductivity such as aluminum, for example. As shown in FIGS. 6 (a) and 6 (b), these heat conducting plates serve as gas flow. It joins with the inner peripheral surface of the container 31 so that it may become radial on the plane orthogonal to a direction. The container 31 and the heat conducting member 32 may be integrally formed of a material having a relatively high heat conductivity.

  Further, the heat conducting member 32 and the housing 31 are formed with a coating film by, for example, electroless nickel plating, and corrosion due to gas, water vapor, or the alkaline carbon dioxide absorbent 10 is prevented.

  The canister 3 is mounted on a canister mounting portion provided on the circulation path of the ventilator, so that the inlet 13 and the outlet 34 are partitioned.

  Since the container 31 and the heat conducting member 32 are integrally connected to the canister 3 configured as described above, the heat transmitted from the heat generating portion of the carbon dioxide absorbent 10 to the heat conducting member 32 is accommodated in the canister 3. Is transmitted to the outer peripheral side portion of the carbon dioxide absorbent 10 in contact with the inner peripheral surface of the container 31. For this reason, in the canister 3, the temperature difference which arises in the center side site | part and the outer peripheral side site | part of the carbon dioxide absorbent 10 of the container 31 is suppressed. At the same time, in this canister 3, the temperature range generated in the gas flow direction of the carbon dioxide absorbent 10 is also suppressed by the heat conducting member 32 arranged along the gas flow direction.

  As described above, according to the canister 3, the heat conduction member 32 is connected to the inner periphery of the container 31, so that the heat of the heat generating part is passed through the heat conduction member 32 and the inner periphery of the container 31. Since the carbon dioxide absorbent 10 in the outer peripheral portion that contacts the surface is heated, the temperature difference between the carbon dioxide absorbent 10 in the outer peripheral portion and the carbon dioxide absorbent 10 in the central portion is suppressed, and heat conduction is performed. The temperature difference between the heat generating portion and the carbon dioxide absorbent 10 in the downstream portion is suppressed by the member 32. For this reason, as for the carbon dioxide absorbent 10 in the container 31, the temperature distribution of each site | part is equalize | homogenized as a whole. Therefore, in the canister 3, a decrease in reactivity is suppressed in the entire carbon dioxide absorbent 10 in the container 31, and the reaction efficiency in the entire carbon dioxide absorbent 10 can be improved.

  And according to this canister 3, when soda lime is used as the carbon dioxide absorbent 10, compared with the conventional canister, reaction efficiency can be improved about 30%.

  At first glance, the canister 3 is at risk of cooling the container 31 due to the external temperature. However, the canister 3 is cooled to such an extent that the reactivity of the carbon dioxide absorbent 10 is lowered in normal use at ordinary temperatures. Never happen. For this reason, it is not necessary to provide a heat insulating material etc. in the outer peripheral part of the container 31 in particular, but according to the external environment such as the container 31 being exposed to air blowing, a heat insulating material or a heat insulating material is provided in the outer peripheral part of the container 31. A coating film may be provided.

  The canister 3 according to the third embodiment has a configuration in which a gas introduction pipe is provided in the housing 31. However, the canister 3 is not provided with a gas introduction pipe, and is arranged from one end side to the other end side of the cylindrical housing body. The gas may flow so that the same effect can be obtained and the configuration can be simplified.

(Fourth embodiment)
A canister according to a fourth embodiment will be described with reference to the drawings. The canister of the present embodiment substantially corresponds to a configuration combining the second and third embodiments described above. In other words, the canister of the fourth embodiment has a temperature range generated between the carbon dioxide absorbent 10 at the outer peripheral portion and the carbon dioxide absorbent 10 at the central portion that abuts the inner peripheral surface of the container, and the heat generating portion and the downstream portion. It is the structure which suppresses both the temperature range which arises in the carbon dioxide absorbent 10 of a side part, Comprising: It is the structure which further heats the carbon dioxide absorber 10 of an outer peripheral side part with the gas which passed the carbon dioxide absorbent 10. FIG.

  As shown in FIGS. 7A and 7B, the canister 4 of the present embodiment is provided by being connected to the inner container 41 that stores the carbon dioxide absorbent 10 and the inside of the inner container 41. A heat conducting member 42 and an outer housing 43 that houses the inner housing 41 therein are provided.

  The inner container 41 is formed in a rectangular cylinder shape with a material having a relatively high thermal conductivity such as aluminum, for example, and is provided with an inlet 46 through which gas flows in at one end and absorbs carbon dioxide at the other end. An outlet 47 through which the gas that has passed through the agent 10 flows out is provided. The inner container 41 is provided with a filter 48 at the inlet 46, and the outlet 47 is fixed to the center of the screen member 49. The inner container 41 has a space between the screen member 49 and the bottom surface of the outer container 43, and the outer periphery of the screen member 49 is engaged with the inner periphery of the outer container 43.

  The heat conducting member 42 is composed of a plurality of heat conducting plates made of a material having a relatively high thermal conductivity such as aluminum, for example, and these heat conducting plates are parallel to the gas flow direction and in a direction perpendicular to the flow direction. Each is arranged with a predetermined interval. One side ends of these heat conductive plates are joined to the inner peripheral surface of the inner container 41.

  The outer container 43 is formed in a cylindrical shape with a bottom, and is sized so as to open a predetermined gap between the outer container 43 and the outer peripheral surface of the inner container 41. It flows along the entire circumference of the outer periphery of the container 41. The opening of the outer container 43 constitutes an outlet 50 through which the gas that has flowed along the outer periphery of the inner container 41 flows out into the circulation path. In addition, a coating film is formed on the inner peripheral surface of the outer container 43 by electroless nickel plating or the like, and corrosion due to gas, water vapor, or alkaline carbon dioxide absorbent is prevented.

  The canister 4 is mounted on a canister mounting portion provided on the circulation path of the ventilator, so that the inlet 47 of the inner container 41 and the outlet 50 of the outer container 43 are partitioned.

  In the canister 4 configured as described above, when the carbon dioxide absorbent 10 and the gas chemically react, the heat conduction member 42 in contact with the carbon dioxide absorbent 10 generates heat from the carbon dioxide absorbent 10. The heat of the part is transmitted to each part in the gas flow direction and each part in the radial direction of the inner container 41, and the heat transmitted to the heat conductive member 42 is transmitted to the inner container 41. The temperature range between the heat generating part and the carbon dioxide absorbent 10 at the downstream part is suppressed, and the temperature range between the carbon dioxide absorbent 10 at the outer peripheral part and the carbon dioxide absorbent 10 at the central part is suppressed.

  In addition, in the canister 4, the gas that has passed through the carbon dioxide absorbent 10 in the inner container 41 flows along the outer periphery of the inner container 41, so that the heat of the gas is transmitted to the inner container 41. The carbon dioxide absorbent 10 at the outer peripheral side portion is heated through the inner container 41.

  For this reason, in the carbon dioxide absorbent 10 in the inner container 41, the temperature difference generated between the heat generation part and the unreacted part is further suppressed, and the temperature distribution in each part is made uniform. Further, in this canister 4, since the outer peripheral portion of the inner container 41 is covered with the outer container 43, the carbon dioxide absorbent 10 at the outer peripheral side contacting the inner peripheral surface of the inner container 41 is cooled by the outside air. Is also prevented.

  According to the canister 4 described above, the heat transfer member 42 connected to the inner periphery of the inner container 41 and the outer container 43 that accommodates the inner container 41 are provided in the inner container 41. The temperature distribution of each part can be made more uniform throughout the carbon dioxide absorbent 10. Therefore, this canister 4 can suppress the fall of the reactivity in the downstream site | part of the outer peripheral side of the carbon dioxide absorbent 10 especially, and can further improve the reaction efficiency in the carbon dioxide absorbent 10 whole.

  And according to the canister of this embodiment, even when a plurality of types of soda lime having different contents of sodium hydroxide (NaOH) or potassium hydroxide (KOH) as a catalyst are used as a carbon dioxide absorbent, Although the reactivity differs depending on the composition of soda lime and there is a difference in carbon dioxide absorption capacity, the carbon dioxide absorption capacity can be improved by about 25% to 30%. Examples of multiple types of soda lime include those containing both NaOH and KOH (high reactivity), those containing very small amounts of NaOH and KOH (slightly low reactivity), and those not containing NaOH or KOH (Low reactivity).

  Further, the carbon dioxide absorbent used in the canister according to the present invention is not limited to soda lime, and may be appropriately selected as necessary, and can absorb carbon dioxide regardless of the composition of the carbon dioxide absorbent. Of course, the effect of improving can be obtained.

  The heat conducting member and the reaction container according to the present invention are applied to a canister provided in an anesthesia machine.For example, a circulation system of air in an airtight space such as a space station, a submarine, and a shelter, Of course, it is also suitable as other respirators such as a circulating portable underwater respirator used in scuba diving.

(Example)
Using the canister 3 of the third embodiment described above, the temperature change of each part of the carbon dioxide absorbent 10 in the container 31 was measured. In FIG. 8, the schematic diagram for demonstrating the temperature measurement position of a carbon dioxide absorber is shown. In FIG. 9, the result of the temperature change of each site | part of a carbon dioxide absorbent in an Example is shown.

  As the carbon dioxide absorbent 10, 1 kg of soda lime was filled in the container 31. Then, a pseudo anesthesia circuit equipped with a 3 L simulated lung was prepared, carbon dioxide was supplied from the simulated lung at a flow rate of 300 ml / min, the ventilation volume per one time was 700 ml, the respiratory rate was 12 times / min, Ventilation rate 8.4 L / ml), supplying fresh gas (oxygen) to the circulation system at a flow rate of 500 ml / min, until the end time when the carbon dioxide concentration (partial pressure) of the gas that passed through the canister 3 becomes 5 mmHg The elapsed time was measured.

  As shown in FIG. 8, about the outer peripheral side part and center side part (part between the inner peripheral surface of the container 31 and the outer peripheral surface of the gas introduction pipe 16) of the carbon dioxide absorbent 10 in the container 31, the gas Each temperature sensor was arranged in each of the upstream part, the middle stream part, and the downstream part in the flow direction, and the temperature change from the start of use of the canister to the end time was measured. Further, the temperature change in the vicinity of the outlet 34 of the container 31 was also measured. In FIG. 8, the outer peripheral side upstream portion of the carbon dioxide absorbent 10 is P1, the outer peripheral side intermediate portion P2, the outer peripheral downstream portion P3, the central upstream portion P4, and the central intermediate flow portion P5. A center downstream side part is set to P6, and the outflow port 34 vicinity of the container 31 is set to P7.

  As shown in FIG. 9, in the canister 3 of the embodiment, the temperature difference between the central side portion and the outer peripheral side portion is greatly reduced from the start to the end of use, and the upstream side portion, the midstream side portion, the downstream side The temperature difference generated in the side part was also greatly reduced. And in the canister 3 of a present Example, the temperature distribution of each site | part of the carbon dioxide absorbent 10 was substantially equalized from the use start to the end.

(Comparative example)
Using a conventional canister, the same structure and outer dimensions of the container excluding the heat conducting member were the same, and the same part of the carbon dioxide absorbent was measured under the same conditions as in the first example. In FIG. 10, the result of the temperature change of each site | part of a carbon dioxide absorbent in a comparative example is shown.

  As shown in FIG. 10, in the conventional canister, the exothermic parts that reach the maximum temperature of the carbon dioxide absorbent 10 are the center side upstream part P4, the center side middle stream part P5, and the center side downstream part P6 over time. The maximum temperature reached about 50 ° C. From the start to the end of use, the temperature at the outer peripheral part was clearly lower than that at the central part, and the temperature difference from the intermediate part gradually increased after 3 hours. In the conventional canister, the concentration of carbon dioxide in the passed gas became 5 mmHg in about 7 hours (average 436 minutes).

  As described above, in this example, the maximum temperature of the carbon dioxide absorbent 10 is about 45 ° C., which is about 5 ° C. lower than the comparative example, and the usable time is 9 hours (average 570 minutes). It was possible to extend the time by 2 hours. In addition, when it is necessary to avoid a decrease in the maximum temperature in the canister 3, a heat insulating material or the like may be provided on the outer peripheral portion of the container 31.

  FIG. 11 shows the temperature difference between the exothermic part (reaction part) at which the carbon dioxide absorbent 10 locally reaches the maximum temperature and the vicinity of the outlet for the example and the comparative example.

  As described above, the water vapor generated at the heat generating portion of the carbon dioxide absorbent is cooled by the time it reaches the outlet, and condensation occurs in the carbon dioxide absorbent at the downstream side of the heat generating portion. The temperature range near the outlet reflects the degree of increase in moisture content at the downstream site. As shown in FIG. 11, in the conventional canister, the temperature range between the heat generating part and the vicinity of the outlet is relatively large, but in this example, the temperature range between the heat generating part and the vicinity of the outlet is reduced. Also from this result, the conventional canister causes an increase in the moisture content in the downstream portion of the carbon dioxide absorbent, and this example shows that the increase in the moisture content in the downstream portion is suppressed.

Table 1 shows the moisture content (%) of each part of the carbon dioxide absorbent when the concentration of the carbon dioxide absorbent that has passed through the canister reaches 5 mmHg, in comparison with the example and the comparative example.

  Carbon dioxide absorbents need moderate moisture to absorb carbon dioxide well, and the reactivity, i.e., the ability to absorb, decreases even when dried, but the ability to absorb even when the moisture content is excessively increased. Reduce. As described above, the water content of the carbon dioxide absorbent is about 15 to 20%.

  The carbon dioxide absorbent before the start of the experiment (unused) had a water content of about 15.5%. Before the start of the experiment, the carbon dioxide absorbent in the container had a sufficient water content and sufficient reactivity.

  As shown in Table 1, after the end of the experiment, in both the examples and the comparative examples, in the carbon dioxide absorbent in the container, the water content in the central part and the downstream part was lowered. This is because the carbon dioxide absorbent absorbs carbon dioxide and consumes 1 mol of water contained in the carbon dioxide absorbent to release 13.7 kcal of heat and 2 mol of water vapor. It is normal for the moisture content of the absorbent to decrease.

  In the canister of the comparative example, the water content in the downstream portion of the carbon dioxide absorbent increased to 15% or more, and reached 32.5% particularly in the outer peripheral side downstream portion. Such an excessive increase in the moisture content is a result of the condensation of the gas containing water vapor generated in the reaction part due to the relative decrease in temperature at the outer peripheral side downstream portion. And, the carbon dioxide absorbent that has an excessive water content is significantly reduced in reactivity. Accordingly, the gas passing through the outer peripheral side downstream portion P3 of the carbon dioxide absorbent reaches the outlet of the container without being absorbed by the carbon dioxide absorbent, and still remains in the central downstream portion P6. Despite the presence of many porous particles with sufficient reactivity, the concentration of the treated gas has increased. That is, channeling occurs due to a local decrease in the reactivity of the carbon dioxide absorbent in the outer peripheral side downstream portion.

  On the other hand, in the canister 3 of the example, the increase in the moisture content in the downstream portion was suppressed to a small level. In particular, in the outer peripheral side downstream part P3, the increase in the water content was significantly suppressed as compared with the comparative example. This is because the temperature difference generated at each part of the carbon dioxide absorbent is made uniform, and the moisture content is prevented from increasing due to condensation. Therefore, in the canister 3 of the example, the carbon dioxide absorbent does not have a portion where the moisture content is excessively increased, and there is no portion where the absorption capacity is reduced, so that channeling due to a local decrease in reactivity occurs. Does not occur.

1 is a perspective view schematically showing a canister according to a first embodiment. It is a perspective view which shows a heat conductive member typically. It is a perspective view which shows the other example of a heat conductive member. It is a perspective view which shows typically the canister which concerns on 2nd Embodiment. It is a figure which shows typically the canister which concerns on 3rd Embodiment. It is a figure which shows a container and a heat conductive member, Comprising: (a) is a top view, (b) is a see-through | perspective side view. It is a figure which shows typically the canister which concerns on 4th Embodiment, (a) is a top view, (b) is a longitudinal cross-sectional view. It is a schematic diagram for demonstrating the temperature measurement position of the carbon dioxide absorbent in an Example and a comparative example. It is a figure for demonstrating the temperature distribution in the canister of a 1st Example. It is a figure for demonstrating the temperature distribution in the conventional canister. It is a figure which shows the temperature difference of the carbon dioxide absorbent in a 1st Example and the conventional canister.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Canister 10 Carbon dioxide absorbent 11 Container 12 Heat conduction member 13 Inlet 14 Outlet 16 Gas introduction pipe

Claims (11)

A heat conduction member mounted in a container that contains a carbon dioxide absorbent and has an inlet into which a gas containing carbon dioxide flows and an outlet from which the gas that has passed through the carbon dioxide absorbent flows out,
It is arranged along the flow direction of the gas passing through the carbon dioxide absorbent so as to heat the other part of the carbon dioxide absorbent with the heat of the exothermic part of the carbon dioxide absorbent. Heat conduction member. A container that contains a carbon dioxide absorbent and has an inlet into which a gas containing carbon dioxide flows, and an outlet from which the gas that has passed through the carbon dioxide absorbent flows out;
Heat for heating the other part of the carbon dioxide absorbent with the heat of the exothermic part of the carbon dioxide absorbent, which is disposed in the container along the flow direction of the gas passing through the carbon dioxide absorbent. A conductive member;
A reaction vessel.   The reaction container according to claim 2, wherein the heat conducting member is disposed so as to cover an upstream end and a downstream end of the carbon dioxide absorbent with respect to a flow direction of the gas.   The reaction container according to claim 2 or 3, wherein the heat conducting member is disposed so as to extend from the vicinity of the center side of the container to the vicinity of the peripheral surface side in a direction orthogonal to the flow direction of the gas.   The reaction container according to any one of claims 1 to 4, wherein the heat conducting member is connected to the container.   The reaction container according to any one of claims 1 to 5, wherein a heat insulating means for insulating heat from outside air is provided on an outer peripheral portion of the container. An inner container having a carbon dioxide absorbent, an inlet into which a gas containing carbon dioxide flows, and an outlet from which the gas that has passed through the carbon dioxide absorbent flows out;
Storing the inner container inside, and an outer container for flowing the gas flowing out from the outlet along the outer periphery of the inner container;
A reaction vessel.   In the inner container, heat for heating other parts of the carbon dioxide absorbent with the heat of the heat producing part of the carbon dioxide absorbent along the flow direction of the gas passing through the carbon dioxide absorbent. The reaction container according to claim 7, wherein a conductive member is provided.   The reaction container according to any one of claims 1 to 8, wherein the reaction container is arranged on a circulation path of the gas included in a respiratory organ. A carbon dioxide absorbent reaction method in which a gas containing carbon dioxide is passed through a carbon dioxide absorbent housed in a container to cause a chemical reaction between the gas and the carbon dioxide absorbent,
A method for reacting a carbon dioxide absorbent, wherein the other part of the carbon dioxide absorbent is heated by heat of a heat generating part of the carbon dioxide absorbent by a heat conducting member provided in the container. A carbon dioxide absorbent reaction method in which a gas containing carbon dioxide is passed through a carbon dioxide absorbent housed in a container to cause a chemical reaction between the gas and the carbon dioxide absorbent,
The gas that has passed through the carbon dioxide absorbent is caused to flow along the outer periphery of the container, and the carbon dioxide absorbent is heated by the heat of the gas through the container. The reaction method of the agent.

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