JP2015039656A - Gas removing method, gas removing system, and air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas removing method, a gas removing system, and an air conditioner which reduce formaldehyde concentration efficiently in a short time.SOLUTION: A gas removing method removes aqueous gas contained in gas in a target space S by using an air conditioner A connected to the target space S. The air conditioner A includes a cooling coil 4 and a humidifier 6. Cooling by the cooling coil 4 and humidification by the humidifier 6 are simultaneously carried out by the air conditioner A, and a water screen is formed on the cooling coil 4 by humidification. The gas in the object space S is brought into contact with the water screen to dissolve the aqueous gas contained in the gas with the water screen. The air conditioner A further includes a heating coil 5. Heating by the heating coil 5 is simultaneously carried out in addition to the cooling by the cooling coil 4 and humidification by the humidifier 6 so that a temperature in the target space S reaches a predetermined temperature or higher.

Description

  The present invention relates to a gas removal method, a gas removal system, and an air conditioner that remove water-soluble gas contained in a gas in a target space.

  Formaldehyde is used in the manufacture of pharmaceuticals and cosmetics, and in the biological clean rooms of medical facilities for the sterilization of airborne bacteria. Conventionally, after the inside of the target space is sterilized with formaldehyde, the formaldehyde is discharged without being processed outside the target space, or is detoxified by a decomposition and removal device and discharged.

  As an apparatus for decomposing and removing formaldehyde, an apparatus for oxidizing and decomposing formaldehyde by mixing a gas containing formaldehyde and an ozone-containing gas has been proposed. In addition, various apparatuses such as an apparatus using a catalyst or an adsorbent have been proposed. Conventionally, the concentration of formaldehyde in the target space has been reduced by installing such a device in the target space.

JP 2005-204936 A JP 2004-163055 A

  By the way, formaldehyde became the object of regulation by the revision of the specific chemical substance disorder prevention regulations. Specifically, the concentration standard value of formaldehyde when workers enter the target space after fumigation related to formaldehyde is required to be 0.1 ppm or less.

  At the time of fumigation, formaldehyde solidifies and adheres as paraformaldehyde to the wall surface of the target space, HEPA filter, or the like. The paraformaldehyde is sublimated and released from the wall surface or the like as the formaldehyde concentration in the target space decreases when formaldehyde is released to the outdoors or decomposed and removed. For this reason, in order to quickly reduce the concentration of formaldehyde to 0.1 ppm or less, it is necessary to release to the outdoors, that is, to increase the ventilation rate or to greatly increase the decomposition and removal capacity, but this is economically difficult. It was.

  Actually, with the conventional ventilation amount and the ability to decompose and remove formaldehyde to the outside, it sometimes took several days for the concentration to become 0.1 ppm or less. This has been a factor of reducing the production efficiency because it is necessary to periodically sterilize with formaldehyde in the production of pharmaceuticals and the like. Therefore, a technique for reducing the formaldehyde concentration to 0.1 ppm or less in a shorter time has been demanded.

  The present invention has been proposed to solve the above problems. An object of the present invention is to provide a gas removal method, a gas removal system, and an air conditioner that provide a water film on a cooling coil of an air conditioner to reduce the concentration of a water-soluble gas such as formaldehyde in a short time. It is.

In order to achieve the above object, the gas removal method of the present invention has the following characteristics.
(1) A gas removal method for removing a water-soluble gas contained in a gas in the target space using an air conditioner connected to the target space, wherein the air conditioner has a cooling coil and a humidifier. And causing the air conditioner to simultaneously perform cooling by the cooling coil and humidification by the humidifier, forming a water film on the cooling coil by the humidification, and forming the water film on the water film in the target space. A gas is brought into contact, and a water-soluble gas contained in the gas is dissolved in the water film.

(2) The air conditioner further includes a heating coil. In addition to cooling by the cooling coil and humidification by the humidifier, heating by the heating coil is simultaneously performed, and the temperature of the target space is set to a predetermined temperature. It is good also as above.
(3) Humidification by the humidifier may be performed on the cooling coil from the upstream side of the cooling coil.

(4) The water-soluble gas concentration in the target space may be measured, and the amount of the water film may be adjusted based on the measured water-soluble gas concentration.
(5) Measure the temperature and humidity of the target space, control the cooling coil and the humidifier based on the measured humidity value, and control the heating coil based on the measured temperature value Also good.

  In addition, each said form can also be caught as invention of a gas removal system and an air conditioner.

  ADVANTAGE OF THE INVENTION According to this invention, the gas removal method, gas removal system, and air conditioner which reduce formaldehyde density | concentration efficiently and in the short term can be provided.

It is a lineblock diagram showing an example of the gas removal system concerning a 1st embodiment. It is a block diagram which shows an example of the control apparatus of the gas removal system concerning 1st Embodiment. It is a schematic diagram which shows the outline | summary of the control concerning 1st Embodiment. It is a flowchart which shows the removal flow of the water-soluble gas concerning 1st Embodiment. It is an air line figure which shows the state of the gas at the time of the gas removal by the gas removal system concerning 1st Embodiment. It is a graph which shows the gas removal capacity of the gas removal system concerning 1st Embodiment, and the conventional decomposition device. It is a block diagram which shows an example of the gas removal system concerning 2nd Embodiment. It is a block diagram which shows an example of the control apparatus of the gas removal system concerning 2nd Embodiment. It is an air line figure which shows the state of the gas at the time of the gas removal by the gas removal system concerning 2nd Embodiment. It is an air line figure which shows the state of the gas at the time of manufacturing environment by the gas removal system concerning 2nd Embodiment. It is a block diagram which shows an example of the gas removal system concerning 3rd Embodiment. It is a block diagram which shows an example of the control apparatus of the gas removal system concerning 3rd Embodiment.

[First Embodiment]
[1. overall structure]
Hereinafter, embodiments of a gas removal system according to the present invention will be described with reference to the drawings. The gas removal system has an air conditioner A shown in FIG. 1 and a control device C shown in FIG. The gas removal system removes water-soluble gas contained in the gas in the target space S using the air conditioner A connected to the target space S. The air conditioner A normally air-conditions the target space, and at the time of removing the water-soluble gas, a water film is formed on a cooling coil described later to dissolve and remove the water-soluble gas. Examples of the water-soluble gas to be removed include formaldehyde and ammonia, but other gases can be removed as long as they are water-soluble. In the following, for convenience of explanation, it is assumed that there is no cooling / heating load in the target space S or by a duct.

  The target space S has an exhaust port 10a and an air supply port 10b connected to the air conditioner A. A dust collection filter such as a HEPA filter is provided in each of the exhaust port 10a and the air supply port 10b. The target space S is provided with a ventilation port 10c, and the other end of the connected duct communicates with the outside.

  Inside the object space S, a thermometer T and a hygrometer H are provided. The thermometer T and the hygrometer H are connected to a control device C described later. The installation location of these instruments is not limited to the target space S, and may be provided in a duct between the target space S and the air conditioner A. The hygrometer H may be a dew point thermometer. At the time of removing the water-soluble gas, the water-soluble gas decomposing apparatus F may be disposed in the target space S to decompose and remove the high-concentration water-soluble gas at the initial stage.

[1.1 Air conditioner configuration]
The structure of the air conditioner A used for this embodiment is shown in FIG. Note that reference signs A1 to A5 in FIG. 1 correspond to points indicating air states in the air diagram of FIG. 5 to be described later. The air conditioner A includes a chamber 1 provided with a gas inlet 1a, a gas outlet 1b, and an outside air inlet 1c, and is connected to a target space S such as a clean room.

  The gas introduction port 1 a is an introduction port for gas circulated from the target space S, and is connected to the exhaust port 10 a of the target space S. The gas discharge port 1b is a gas discharge port that is adjusted by the air conditioner A and is supplied to the target space S, and is connected to the air supply port 10b of the target space S. The outside air inlet 1c is an inlet for outside air introduced into the air conditioner A, and the other end of the connected duct communicates with the outside.

  Inside the chamber 1, the pre-filter 2, the medium performance filter 3, the cooling coil 4, the heating coil 5, the humidifier 6, and the adjusted air are discharged from the gas outlet 1 b from the gas inlet 1 a side. A blower 7 is provided. In the following description, the upstream side means the upstream side of the air flow and refers to the gas inlet 1a side of the air conditioner A. The pre-filter 2 and the medium performance filter 3 are filters for collecting dust and the like.

  For example, a cooling water supply line 4 a connected to a cooling water supply device (not shown) such as a refrigerator is connected to the cooling coil 4 and is supplied with cooling water. The cooling water circulating through the cooling coil 4 is configured to be sent again to the cooling water supply device through a pipe (not shown). The cooling water supply line 4a is provided with a valve 4b. The valve 4b is connected to the control device, and the flow rate of the cooling water supplied to the cooling coil 4 is adjusted by adjusting the opening degree.

  The heating coil 5 is connected to a heating source supply line 5a connected to a heating source supply device (not shown) such as a heater, for example, and is supplied with hot water or steam. Note that the hot water and the condensed water of the steam circulated through the heating coil 5 are configured to be sent again to the heat source supply device through a pipe (not shown). A valve 5b is provided in the heat source supply line 5a. The valve 5b is connected to the control device C, and the flow rate of the heat source supplied to the heating coil 5 is adjusted by adjusting the opening degree.

  The humidifier 6 is connected to a humidified steam supply line 6a connected to a humidified steam supply device (not shown), and is supplied with steam used for humidification. A valve 6b is provided in the humidified steam supply line 6a. The valve 6b is connected to the control device C, and the flow rate of the humidified steam supplied to the humidifier 6 is adjusted by adjusting the opening degree. In addition, although the structure which provides a steam humidification nozzle is illustrated in this embodiment, the humidifier 6 is not limited to a vapor | steam spray type, You may use a vaporization type water film or a water spray type.

[1.2 Configuration of control device]
As shown in FIG. 2, the control device C is connected to a hygrometer H and a thermometer T provided in the target space S. The control device C controls the cooling coil 4 and the humidifier 6 based on the value of the hygrometer H. Further, the control device C controls the heating coil 5 based on the value of the thermometer T. Such a control device C is configured by a computer or a dedicated electronic circuit including a CPU and a memory to which an input unit 20 and an output unit 30 are connected and which operates according to a predetermined program.

  In addition, the control apparatus C also has the structure which controls the damper etc. which are provided in the external air inlet 1c, the air blower 7 of the air conditioner A, the pipe provided between the air conditioner A and the target space S, and the like. Yes. Since these structures are the same as those of the prior art, description thereof is omitted.

  The input unit 20 includes an input device that accepts information input from an operator, and an interface that notifies the control device C of the input information. The input unit 20 is a means for an operator to input an operation request to the air conditioner A and a change of a set value, for example. As the input device, for example, a touch panel (including those installed on the display device of the output unit 30), a mouse, a keyboard, and the like can be used.

  The output unit 30 includes an interface that outputs information from the control device C, and a display device that displays a screen that allows the operator to confirm and select operation contents based on the output information. The output unit 30 is means for displaying, for example, a list or a diagram of the state of the air conditioner A, or displaying an alarm for a system or operator operation. As the display device, for example, a display having a display screen such as a liquid crystal display panel can be used.

  Further, the control device C includes a humidity control unit 40 and a temperature control unit 50. Below, the detail of each process part of the control apparatus C is demonstrated. The air conditioner A is controlled in two modes: a normal operation mode in which air conditioning of the target space S is performed, and a water-soluble gas removal mode in which the water-soluble gas in the target space S is removed. In the gas removal mode, different control is performed depending on whether the work is being performed in the target space S or not. Hereinafter, the control device C in the water-soluble gas removal mode will be described, and the control during the normal operation is the same as the conventional one, and will be omitted.

[1.2.1 Configuration of humidity control unit]
The humidity control unit 40 is a processing unit that controls the cooling coil 4 and the humidifier 6 of the air conditioner A based on the measurement value of the hygrometer H. That is, the humidity control unit 40 is a processing unit that performs control for causing the air conditioner A to simultaneously perform cooling by the cooling coil 4 and humidification by the humidifier 6. By such control of the humidity control unit 40, moisture due to humidification is condensed on the cooling coil 4 of the air conditioner A to form a water film. In the gas removal system, the gas in the target space is brought into contact with the water film, and the water-soluble gas contained in the gas is dissolved in the water film to remove the water-soluble gas.

  The humidity control unit 40 includes a humidity storage unit 41, a humidity comparison unit 42, a cooling condition determination unit 43a, a humidification condition determination unit 43b, a cooling coil control unit 44a, and a humidifier control unit 44b. The humidity storage unit 41 includes a cooling humidity storage unit 41a and a humidification humidity storage unit 41b. The cooling humidity storage unit 41 a is a unit that stores humidity serving as a reference for controlling the cooling coil 4. The humidifying / humidifying storage unit 41b is a unit that stores humidity serving as a reference for controlling the humidifier 6. Each stored humidity may be a relative humidity or a dew point temperature. Hereinafter, for convenience of explanation, it is assumed that the dew point temperature is stored as humidity.

  For example, when the gas removal system is used after decomposing a high-concentration water-soluble gas by the water-soluble gas decomposing apparatus F, the dew point temperature assuming that about 5 ppm of the water-soluble gas is removed may be stored. When removing 5 ppm formaldehyde, the dew point temperature stored in the cooling humidity storage unit 41a is preferably 12 ° C., and the dew point temperature stored in the humidification humidity storage unit 41b is preferably 21.5 ° C.

  Moreover, when removing high concentration water-soluble gas, it is necessary to increase the amount of water films on the cooling coil 4. For example, when removing 1000 ppm of formaldehyde, the dew point temperature stored in the cooling humidity storage unit 41a is preferably 12 ° C., and the dew point temperature stored in the humidification humidity storage unit 41b is preferably 25 ° C. or higher.

  The humidity comparison unit 42 is, for example, a processing unit that compares a plurality of numerical values to determine the magnitude of the numerical values and determines a difference between the numerical values, and includes a cooling humidity comparison unit 42a and a humidification humidity comparison unit 42b. The cooling humidity comparison unit 42a compares the measured value of the hygrometer H digitalized by an A / D conversion unit (not shown) with the dew point temperature value stored in the cooling humidity storage unit 41a, and compares the comparison result with the cooling condition. It outputs to the determination part 43a. Similarly, the humidification humidity comparison part 42b compares the measured value of the hygrometer H with the dew point temperature value memorize | stored in the humidification humidity memory | storage part 41b, and outputs a comparison result to the humidification condition determination part 43b. When the relative humidity is compared by the humidity comparison unit 42, a relative hygrometer is used instead of the hygrometer H or a processing unit for calculating the relative temperature from the values of the hygrometer H and the thermometer T is provided. What is necessary is just to output to the humidity comparison part 42.

  The cooling condition determination unit 43a is a processing unit that receives the comparison result output from the cooling humidity comparison unit 42a and obtains the cooling amount of the cooling coil 4 based on the comparison result. The cooling condition determination unit 43 outputs a condition for controlling the cooling coil 4 so that the dew point temperature in the target space S becomes the set dew point temperature to the cooling coil control unit 44a. For example, when the dew point temperature stored in the cooling humidity storage unit 41a is 12 ° C. and the value of the hygrometer H is 14 ° C., the humidity in the target space S is changed from 14 ° C. to 12 ° C. The opening of the valve 4b is increased, and the cooling coil 4 is output to be cooled.

  The humidification condition determination unit 43b is a processing unit that receives the comparison result output from the humidification humidity comparison unit 42b and obtains the humidification amount of the humidifier 4 based on the comparison result. The humidification condition determination unit 43 outputs a condition for controlling the humidifier 6 to the humidifier controller 44b so that the dew point temperature in the target space S becomes the set dew point temperature. For example, when the dew point temperature stored in the humidification humidity storage unit 41a is 21.5 ° C. and the value of the hygrometer H is 17 ° C., the humidity in the target space S is 17 ° C. to 21.5 ° C. Then, the opening degree of the valve 6b is increased so that humidification by the humidifier 6 is performed.

  The cooling coil control unit 44a is a processing unit that controls the opening degree of the valve 4b of the cooling coil 4 according to the cooling condition determined by the cooling condition determination unit 43a. Moreover, the humidifier control means 44b is a means for adjusting the opening degree of the valve 6b of the humidifier 6 according to the humidification condition determined by the humidification condition determination unit 43b.

[1.2.2 Configuration of temperature controller]
The temperature control unit 50 is a processing unit that controls the heating coil 5 of the air conditioner A based on the measurement value of the thermometer T. In the gas removal system, the humidity control unit 40 can control the heating coil 5 by the temperature control unit 50 in addition to the cooling by the cooling coil 4 and the humidification by the humidifier 6 at the same time.

  The temperature control unit 50 includes a temperature storage unit 51, a temperature comparison unit 52, and a heating condition determination unit 53. The temperature storage unit 51 is a means for storing a temperature serving as a reference for controlling the heating coil 5. At the time of removing the water-soluble gas, the sublimation of the water-soluble gas attached to the wall surface or the like of the target space S is promoted by setting the temperature in the target space S to a predetermined temperature or higher. Accordingly, the stored temperature is preferably higher than about 23 ° C. which is a temperature in a normal manufacturing environment. Specifically, in the target space S, the temperature should be as high as possible within a range that does not cause a problem with the structure such as the manufacturing apparatus or the wall. Preferably, a temperature of 30 to 40 ° C. is stored.

  The temperature comparison unit 52 is a processing unit that compares a plurality of numerical values, for example, and determines a numerical value size difference or a numerical value difference. The temperature comparison unit 52 compares the measured value of the thermometer H converted into a digital signal by an A / D conversion unit (not shown) and the temperature stored in the temperature storage unit 51, and compares the comparison result with the heating condition determination unit 53. Output.

  The heating condition determination unit 53 is a processing unit that receives the comparison result output from the temperature comparison unit 52 and calculates the heating amount of the heating coil 5 based on the comparison result. The heating condition determination unit 53 outputs a condition for controlling the heating coil 5 to the heating coil controller 54 so that the temperature in the target space S becomes the set temperature. For example, when the temperature stored in the temperature storage unit 51 is 35 degrees and the value of the thermometer T is 25 degrees, the valve is set so that the temperature in the target space S is 25 degrees to 35 degrees. The opening of 5b is increased, and the heating coil 4 is output to be heated. The heating coil control means 54 is a processing unit that controls the opening degree of the valve 5b of the heating coil 5 in accordance with the heating condition determined by the heating condition determination unit 53.

[2. Water-soluble gas removal flow]
(Outline of control)
An outline of the control of the control device C will be described below with reference to FIG. First, the control device C performs the control indicated by (1) in the figure during normal air conditioning. Here, the description will be made assuming that the condition of the target space S is adjusted to a temperature of 23 ° C. and a dew point temperature of 12 ° C. First, in the humidity control, when the dew point temperature in the target space S is less than 12 ° C., the control device C performs humidification by adjusting the opening of the valve 6b of the humidifier 6 so that the dew point temperature becomes 12 ° C. .

  On the other hand, when the dew point temperature exceeds 12 ° C., the control device C performs cooling by adjusting the opening of the valve 4b of the cooling coil 4 so that the dew point temperature becomes 12 ° C., and dehumidifies. As described above, during normal air conditioning, the air conditioner A performs either dehumidification by the cooling coil 4 or humidification by the humidifier 6 based on whether or not the humidity in the target space S is equal to or higher than the set humidity. That is, during normal air conditioning, the cooling coil 4 and the humidifier 6 are not operated simultaneously.

  Similarly, in the temperature control, when the temperature in the target space S is less than 23 ° C., the control device C performs heating by adjusting the opening of the valve 5b of the heating coil 5 so that the temperature becomes 23 ° C. On the other hand, when the temperature exceeds 23 ° C., the control device C performs cooling by adjusting the opening of the valve 4 b of the cooling coil 4 so that the temperature becomes 23 ° C.

  Next, the controller C performs the control shown in (2) in the figure when removing the water-soluble gas. Here, the description will be made assuming that the condition of the target space S is adjusted to a temperature of 35 ° C. and a dew point temperature of 21.5 ° C. In the following description, it is assumed that the dew point temperature 12 ° C. is stored in the cooling humidity storage unit 41a and the dew point temperature 21.5 ° C. is stored in the humidification humidity storage unit.

  The humidity control unit 40 operates the cooling coil 4 and the humidifier 6 at the same time. That is, when the dew point temperature in the target space S exceeds 12 ° C., the humidity control unit 40 performs cooling by adjusting the opening of the valve 4 b of the cooling coil 4 so that the dew point temperature becomes 12 ° C. At the same time, when the dew point temperature in the target space S is less than 21.5 ° C., the humidity controller 40 adjusts the opening of the valve 6b of the humidifier 6 so that the dew point temperature is 21.5 ° C. Do. Thus, by always humidifying and simultaneously cooling the cooling coil 4, dew condensation water is generated on the cooling coil 4 and a water film is formed.

  Since cooling is always performed by the cooling coil 4, the gas on the downstream side of the cooling coil 4 has a low temperature. Therefore, in the temperature control, when the temperature in the target space S is less than 35 ° C., the temperature control unit 50 performs heating by adjusting the opening of the valve 5b of the heating coil 5 so that the temperature becomes 35 ° C. Thus, by reheating the gas once cooled by the heating coil 5, the temperature in the target space S is maintained at 35 ° C. which is a predetermined temperature condition.

(Water-soluble gas removal flow)
Next, the flow of water-soluble gas removal by the air conditioner A will be described with reference to FIG. In the same manner as described above, the condition of the target space S will be described as adjusting the temperature to 35 ° C. and the dew point temperature to 21.5 ° C. In the following description, it is assumed that the dew point temperature 12 ° C. is stored in the cooling humidity storage unit 41a and the dew point temperature 21.5 ° C. is stored in the humidification humidity storage unit 42b.

  Moreover, the state of the gas in the target space S is shown in the air diagram of FIG. 5 corresponding to each operation flow. In addition, in FIG. 5, each point shown by A1-A5 respond | corresponds to the state of each gas demonstrated below. Similarly, also in FIG. 1, the points corresponding to FIG. Specific values such as gas temperature and humidity shown below are merely examples, and the present invention is not limited to these numerical values.

  As a premise, during the operation of the air conditioner A, the control device C adjusts the opening degree of the damper provided in the outside air introduction port 1c so as to introduce a very small amount of outside air so that the inside of the target space S becomes a positive pressure. doing. A1 in FIG. 5 indicates the state of the outside air to be introduced. The introduced outside air is mixed with the gas circulated from the inside of the target space S in the air conditioner A, and becomes a gas having a condition indicated by A2 in FIG. Hereinafter, the operation flow will be described for the gas after the condition A2.

  When the operation of the air conditioner A is started, the detected value of the hygrometer H is output to the humidity control unit 40 of the control device C (step S01A). The cooling humidity comparison unit 42a reads the dew point temperature stored in the cooling humidity storage unit 41a, compares it with the value of the hygrometer H, and outputs the comparison result to the cooling condition determination unit 43a. Based on the comparison result, the cooling condition determination unit 43a determines a cooling condition for controlling the cooling coil 4 so that the dew point temperature becomes 12 ° C. The cooling condition determination unit 43a controls the cooling coil 4 by outputting the determined cooling condition to the cooling coil control unit 44a.

  At the same time, the humidification humidity comparison unit 42 b reads the dew point temperature stored in the humidification humidity storage unit 41 b, compares it with the value of the hygrometer H, and outputs the comparison result to the humidification condition determination unit 44. Based on the comparison result, the humidification condition determination unit 43b determines the humidification condition for controlling the humidifier 6 so that the dew point temperature is 21.5 ° C. The humidification condition determination unit 43b outputs the determined humidification condition to the humidifier control means 44b to control the humidifier 6 (step S02A). As described above, when the humidification is performed and the cooling coil 4 is continuously cooled, condensed water is generated on the cooling coil 4 and a water film is formed.

  The humidity of the target space S is detected again, and if the predetermined humidity has not been reached (NO in step S03A), steps S01A to S03A are repeated. That is, when the cooling coil 4 is cooled (dehumidified) and the humidifier 6 is simultaneously humidified, steps S01A to S03A are repeated until the dew point temperature in the target space S reaches 21.5 ° C.

  When the operation of the air conditioner A is started, the detected value of the thermometer T is output to the temperature controller 50 of the control device C (step S01B). The temperature comparison unit 52 reads the temperature stored in the temperature storage unit 51, compares it with the value of the thermometer T, and outputs the comparison result to the heating condition determination unit 53. The heating condition determination unit 53 determines a heating condition for controlling the heating coil 5 so that the temperature becomes 35 ° C. based on the comparison result. The heating condition determination unit 53 controls the heating coil 5 by outputting the determined heating condition to the heating coil controller 54 (step S02B).

  The temperature of the target space S is detected again, and if the predetermined temperature has not been reached (NO in step S03B), steps S01B to S03B are repeated. That is, even if the cooling coil 4 is being cooled, steps S01B to S03B are repeated until the temperature in the target space S reaches 35 ° C.

  The gas A2 introduced into the air conditioner A first comes into contact with the cooling coil 4 (step S04). The gas A2 in contact with the cooling coil 4 is a gas having the condition indicated by A3 in FIG. That is, the A2 gas having an absolute humidity of 15.5 g / kg ′ is condensed with moisture by contacting the cooling coil 4 to become an A3 gas having an absolute humidity of 8.5 g / kg ′. At this time, the water-soluble gas contained in the gas dissolves in the water film formed on the cooling coil 4.

  The gas of A3 is cooled by the cooling coil 4 and the temperature is lowered to 12 ° C. The A3 gas contacts the heating coil 5 (step S05). The gas of A3 that has come into contact with the heating coil 5 is a gas having a condition indicated by A4 in FIG. That is, A3 gas having a temperature of 12 ° C. becomes A4 gas having a temperature of 35 ° C. by contacting the heating coil 5.

  This A4 gas contacts the humidifier 6 (step S06). The gas of A4 that has come into contact with the humidifier 6 is a gas having a condition indicated by A5 in FIG. That is, the A4 gas having an absolute humidity of 8.5 g / kg ′ is humidified by contacting the humidifier 6 and becomes an A5 gas having an absolute humidity of 16 g / kg ′.

  This A5 gas, that is, a gas having a temperature of 35 ° C. and a dew point temperature of 21.5 ° C. is caused to flow toward the target space S by the blower 7 and is supplied to the target space S. In the target space S, the solid water-soluble gas adhering to the wall surface of the target space S is sublimated again and released by the A5 gas having a temperature of 35 ° C. The water-soluble gas in the target space S circulates with the gas flow of A5 and is introduced into the air conditioner A. That is, the control of the air conditioner A in steps S01 to S03 and the gas flow in steps S04 to S06 are continuously performed until the water-soluble gas concentration becomes a certain value or less.

[3. Water-soluble gas removal ability]
Regarding the gas removal system operating as described above, the relationship between the treatment air volume and the water-soluble gas concentration will be described in comparison with a water-soluble gas decomposition apparatus using a conventional catalyst. FIG. 6 is a graph showing the relationship between elapsed time and gas concentration when formaldehyde in the target space is removed using a conventional water-soluble gas decomposition apparatus and the gas removal system of the present embodiment. The calculation was performed assuming that the concentration of formaldehyde in the target space at the time of removing the water-soluble gas was 2000 ppm, the volume of the target space was 33 m ³ , and the amount of formaldehyde gas generated from the target space was constant at 0.05 g / h.

In the conventional water-soluble gas decomposition apparatus, it is an economical and standard usage method to set the number of circulations to be about 3 times / h. Therefore, when processing the target space having an air volume of 33 m ³ , the processing air volume is about 100 m ³ / h. The removal efficiency at the inlet / outlet of the water-soluble gas decomposition apparatus is about 100%.

On the other hand, in the present gas removal system, for example, the number of circulations of the air conditioner in the medical product manufacturing facility is generally about 30 times / h. Therefore, when processing the target space having an air volume of 33 m ³ , the processing air volume is about 1000 m ³ / h. The removal efficiency at the inlet / outlet of the present gas removal system varies with the area of the water film of the cooling coil 4 and the amount of water, but is about 40 to 70%. If the removal efficiency is 50%, the processing air volume converted to 100% removal efficiency can be calculated as 500 m ³ / h.

  As is apparent from the graph of FIG. 6, the conventional water-soluble gas decomposition apparatus and the present gas removal system have a large difference in the water-soluble gas decreasing rate and the concentration at which the gas concentration stops decreasing. That is, in the conventional decomposition apparatus, the gas concentration continues to decrease until 3.5 hours after the start of removal, and the decrease in gas concentration stops. The concentration at the time when the decrease in gas concentration is stopped is not 0.1 ppm or less, and is a concentration at which a person cannot enter the target space under the current law.

  On the other hand, in the present gas removal system, the gas concentration quickly decreases within one hour after the start of the removal, and the decrease in gas concentration stops. The concentration at the time when the decrease in the gas concentration stops is 0.1 ppm or less, and is a concentration that does not cause a problem even if a person enters the target space.

  In this assumption, the amount of formaldehyde produced from the target space was set at a constant 0.05 g / h. In practice, the amount of formaldehyde adhering to the wall and the like decreases, so the amount of formaldehyde is also decreasing. That is, by reducing the concentration of formaldehyde in the target space in a short time, the amount of formaldehyde generated from the wall surface or the like can be increased, so that the formaldehyde concentration can be decreased in a shorter time.

[4. effect]
The effects of the present embodiment as described above are as follows.
(1) Let the air conditioner A simultaneously perform cooling by the cooling coil 4 and humidification by the humidifier 6 to form a water film on the cooling coil 4 by humidification, and the gas in the target space S is formed on the water film. Since the water-soluble gas contained in the gas can be dissolved, the concentration of the water-soluble gas can be reduced efficiently and in a short time as described above.

(2) The heating by the heating coil 5 is performed at the same time, and the temperature of the target space S is set to a predetermined temperature or higher, so that the release of the solid water-soluble gas attached to the wall surface of the target space S can be promoted. . Therefore, the water-soluble gas concentration can be reduced more efficiently and in a short time.

(3) Water-soluble gas can be removed using the conventional air conditioner A having the cooling coil 4, the heating coil 5, and the humidifier 6.

[Second Embodiment]
[1. Constitution]
An embodiment of the gas removal system of the second embodiment will be described with reference to FIG. In addition, the codes B1 to B5 and C1 to C5 in FIG. 7 correspond to points indicating air states in the air diagrams of FIGS. 9 and 10 to be described later. In the second embodiment, a humidifier 8 is provided on the upstream side of the cooling coil 4.

  The humidifier 8a should just be provided in the upstream of the cooling coil 4, for example, may be provided in the duct which connects the gas inlet 1a of the air conditioner A, and the exhaust port 10a of the object space S. As the humidifier 8, a water spray type, a vaporization type, or a steam type can be used, but it is particularly preferable to use a water spray type / vaporization type humidifier which is a water humidifier.

  A humidifying water supply line 8a connected to a humidifying water supply device (not shown) is connected to the humidifying device 8, and water used for humidification is supplied. A valve 8b is provided in the humidified water supply line 8a. The valve 8b is connected to the control device C, and the flow rate of the humidified water supplied to the humidifying device 8 is adjusted by adjusting the opening degree. That is, as shown in FIG. 8, the control device C further includes a humidifying device control means 44 c that controls the opening degree of the valve 8 a of the humidifying device 8 in accordance with a control signal from the humidity control unit 40.

[2. Water-soluble gas removal flow]
In one of the controls of the gas removal system having the above-described configuration, humidification is performed by the vaporizing humidifier 8 and the water humidified by the humidifier 6 is condensed on the cooling coil 4 to form a water film. Then, the water-soluble gas is removed with a larger water film moisture content. Although the water-soluble gas can be removed more efficiently and in a short time in addition to the above-described embodiment, the basic operation is the same as that of the above-described embodiment, and detailed description thereof is omitted.

(Constant humidity, temperature rise)
As another control of the gas removal system, there is a method of removing the water-soluble gas by raising only the temperature without raising the dew point temperature of the target space S. Here, the description will be made assuming that the condition of the target space S is adjusted to a temperature of 35 ° C. and a dew point temperature of 12 ° C. In the following description, it is assumed that the dew point temperature 12 ° C. is stored in the cooling humidity storage unit 41a and the dew point temperature 18 ° C. is stored in the humidification humidity storage unit 42b.

  An air diagram showing the state of air corresponding to this control is shown in FIG. Also in FIG. 7, points corresponding to FIG. 9 are indicated by B1 to B5. As in the first embodiment, B1 in FIG. 9 shows the state of the outside air to be introduced. The introduced outside air is mixed with the gas circulated from the inside of the target space S in the air conditioner A, and becomes a gas having the condition shown in B2 of FIG.

  When the operation of the air conditioner A is started, in addition to the control of the cooling coil 4 and the heating coil 5 as in the above embodiment, the humidifier 8 is controlled in this embodiment. That is, the humidification condition determination unit 43b determines the humidification condition for controlling the humidifier 8 so that the dew point temperature becomes 18 ° C. based on the comparison result input from the humidification humidity comparison unit 42b. The humidifying condition determining unit 43b controls the humidifying device 8 by outputting the determined humidifying condition to the humidifying device control means 44c.

  The gas B2 introduced into the air conditioner A first contacts the humidifier 8. The gas of B2 that has come into contact with the humidifier 8 is a gas having the condition shown in B3 of FIG. That is, the B2 gas having an absolute humidity of 8.5 g / kg ′ is humidified by contacting the humidifying device 8 and becomes a B3 gas having an absolute humidity of 13 g / kg ′.

  This B3 gas is in contact with the cooling coil 4. The gas B3 in contact with the cooling coil 4 is a gas having the conditions shown in B4 of FIG. That is, the B3 gas having an absolute humidity of 13 g / kg ′ is condensed with moisture by contacting the cooling coil 4 to become a B4 gas having an absolute humidity of 8.7 g / kg ′. At this time, the water-soluble gas contained in the gas dissolves in the water film formed on the cooling coil 4.

  The gas of B4 is cooled by the cooling coil 4 and the temperature is lowered to 12.5 ° C. This B4 gas comes into contact with the heating coil 5. The gas of B4 that has come into contact with the heating coil 5 is a gas having the condition shown by B5 in FIG. That is, the B4 gas having a temperature of 12.5 ° C. is brought into contact with the heating coil 5 to become a B5 gas having a temperature of 35 ° C. This B5 gas, that is, a gas having a temperature of 35 ° C. and a dew point temperature of 12 ° C. is caused to flow toward the target space S by the blower 7 and is supplied to the target space S. In the target space S, the solid water-soluble gas adhering to the wall surface of the target space S is sublimated again and released by the gas of B5 having a temperature of 35 ° C.

(Constant temperature / constant humidity)
In addition, the control of the gas removal system includes a method of removing water-soluble gas while maintaining the temperature and humidity of the target space S while maintaining the temperature and humidity conditions during normal manufacturing operation in the target space S. Here, the description will be made assuming that the condition of the target space S is adjusted to a temperature of 23 ° C. and a dew point temperature of 12 ° C. The cooling humidity storage unit 41a stores a dew point temperature of 12 ° C, and the humidification humidity storage unit 42b stores a dew point temperature of 12 ° C for humidifier control and a dew point temperature of 21 ° C for humidifier control. explain.

  FIG. 10 shows an air diagram showing the state of air corresponding to this control. Also in FIG. 7, points corresponding to FIG. 10 are indicated by C1 to C5. As in the first embodiment, C1 in FIG. 10 shows the state of the outside air to be introduced. The introduced outside air is mixed with the gas circulated from the target space S in the air conditioner A, and becomes a gas having a condition shown by C2 in FIG.

  The C2 gas introduced into the air conditioner A first contacts the humidifier 8. The gas C2 that has come into contact with the humidifier 8 is a gas having a condition indicated by C3 in FIG. That is, the B2 gas having an absolute humidity of 8.0 g / kg ′ is humidified by being brought into contact with the humidifier 8 to become a C3 gas having an absolute humidity of 10.0 g / kg ′. In this example, the humidifier 8 is water-humidified, so the stored dew point temperature does not rise to 21 ° C. and is 14 ° C.

  This C3 gas is in contact with the cooling coil 4. The gas of C3 that has come into contact with the cooling coil 4 is a gas having a condition indicated by C4 in FIG. That is, the C3 gas having an absolute humidity of 10.0 g / kg ′ is condensed with water by contacting the cooling coil 4 to become a C4 gas having an absolute humidity of 8.7 g / kg ′. At this time, the water-soluble gas contained in the gas is dissolved in the water film formed on the cooling coil 4 when the moisture by the humidifier 8 is cooled.

  The gas of C4 is cooled by the cooling coil 4 and the temperature is lowered to 12.5 ° C. This C4 gas is brought into contact with the heating coil 5. The gas of C4 that has come into contact with the heating coil 5 is a gas having a condition indicated by C5 in FIG. That is, the C4 gas having a temperature of 12.5 ° C. is brought into contact with the heating coil 5 to become a C5 gas having a temperature of 23 ° C., which is a temperature during normal operation. This C5 gas, that is, a gas having a temperature of 23 ° C. and a dew point temperature of 12 ° C. is caused to flow toward the target space S by the blower 7 and is supplied to the target space S. In the target space S, the water-soluble gas in the target space S is circulated together with the air flow of C5 by the gas of C5 and is introduced into the air conditioner A again.

[3. effect]
The effects specific to the present embodiment as described above are as follows.
(1) By providing the humidifier 8 on the upstream side of the cooling coil 4, a water film can be efficiently formed on the cooling coil 4. Therefore, the water-soluble gas concentration can be reduced more efficiently and in a short time.

(2) The humidifier 8 can be installed on the upstream side of the cooling coil 4 and in the external configuration of the air conditioner A such as a duct. Therefore, even when a conventional air conditioner is used, the water-soluble gas concentration can be reduced more efficiently and in a short time.

(3) Without increasing the humidity of the target space S, only the humidity on the upstream side of the cooling coil 4 is increased by using a water humidifying device of water spray or vaporization type humidification, and only the temperature of the target space S is increased to make the water soluble. When removing the characteristic gas, energy used for heating and cooling is reduced as compared with the first embodiment. Therefore, the water-soluble gas concentration can be reduced efficiently and in a short time while improving the energy saving performance.

(4) In the case of removing the water-soluble gas without increasing the temperature and humidity of the target space S, the concentration of the water-soluble gas that is continuously generated during the normal production operation can be efficiently reduced.

[Third Embodiment]
An embodiment of the gas removal system of the third embodiment will be described with reference to FIG. In the third embodiment, a concentration meter G for measuring the concentration of the water-soluble gas is further provided in the target space S. The installation location of the densitometer G is not limited to the target space S, and may be provided in the duct between the target space S and the air conditioner A or inside the air conditioner A. The densitometer G may measure the concentration of water-soluble gas dissolved in the drain water of the air conditioner A.

  As shown in FIG. 12, the cooling humidity storage unit 41a and the humidification humidity storage unit 41b of the humidity storage unit 41 of the control apparatus C each store a plurality of dew point temperatures corresponding to different water-soluble gas concentrations. For example, the humidity corresponding to 5 ppm and the humidity corresponding to 0.5 ppm may be stored. Humidity corresponding to the concentration means humidity in order to form a water film sufficient to remove the water-soluble gas at that concentration.

  A densitometer G provided in the target space S is connected to the control device C. The control device C includes a humidity selection unit 45 that selects a reference humidity for controlling the cooling coil 4 and the humidifier 6 based on the measurement value of the densitometer G. The humidity selection unit 45 includes a cooling humidity selection unit 45a and a humidification humidity selection unit 45b.

  The cooling humidity selection unit 45a is a processing unit that selects humidity from a plurality of humidity stored in the cooling humidity storage unit 41a based on the value of the densitometer G. That is, when the value of the densitometer G is 5 ppm, the humidity stored in association with 5 ppm in the cooling humidity storage unit 41a is selected and output to the cooling humidity comparison unit 42a.

  The humidification humidity selection unit 45b is a processing unit that selects humidity from a plurality of humidity stored in the humidification humidity storage unit 41b based on the value of the densitometer G. That is, when the value of the densitometer G is 5 ppm, the humidity stored in association with 5 ppm in the humidification humidity storage unit 41 b is selected and output to the humidification humidity comparison unit 42 a.

  In the present embodiment having the above-described configuration, based on the current concentration of the water-soluble gas in the target space S, the cooling humidity selection unit 45a is stored from the cooling humidity storage unit 41a, and the humidification humidity selection unit 45b is stored from the humidification humidity. The humidity corresponding to the concentration is selected from the unit 41b. That is, the amount of water film formed on the cooling coil 4 is adjusted by adjusting the cooling amount of the cooling coil 4 and the humidifying amount of the humidifier 6 based on the water-soluble gas concentration in the target space S. Therefore, the amount of water film formed on the cooling coil 4 is an amount that can sufficiently remove the water-soluble gas having a concentration in the target space S.

  In this embodiment, since the amount of water film can be determined in accordance with the water-soluble gas concentration in the target space S, for example, when removal of the water-soluble gas progresses to a low concentration, The amount of water film that has been formed can be reduced. Therefore, it is possible to remove the water-soluble gas efficiently and in a short time while improving the energy saving performance.

[Other embodiments]
(1) In the first embodiment, the mode of adjusting both humidity and temperature with high gas removal efficiency has been described. However, as described in the second embodiment, the temperature does not necessarily have to be 30 ° C. or higher, and can be, for example, a clean room working temperature. For example, when the working temperature is 23 ° C. and the dew point temperature is 12 ° C., the dew point temperature of the cooling humidity storage unit 41a is less than 12 ° C., the dew point temperature of the humidification humidity storage unit 41b is 12 ° C., and the temperature of the temperature storage unit 51 is 23. It can be set to ° C. By this. Also in the first embodiment, it is possible to remove the water-soluble gas while performing the work in the clean room.

  (2) Similarly, also in the first embodiment, the dew point temperature is not necessarily 21.5 ° C., and the humidity in the target space S may not be increased. That is, it can be humidified by the humidifier 6 and cooled (dehumidified) by the cooling coil 4 so that the humidity in the target space S can be kept substantially constant. At that time, the temperature in the target space S may be increased by the heating coil 5 so that the solid water-soluble gas attached in the target space S is re-released.

  (3) In the second embodiment, in order to increase the amount of condensed water in the cooling coil 4, a heating coil may be further provided on the upstream side of the humidifier 8. Moreover, the amount of condensed water can be increased also by making the humidification apparatus 8 into a steam type. Further, as shown in FIG. 7, a second hygrometer H2 may be provided on the upstream side of the cooling coil 4 to control the humidifier 8 on the upstream side. If the humidifier 8 is water-humidified and a sufficient amount of humidification cannot be obtained, in order to increase the amount of the water film of the cooling coil 4 and promote the drainage of the water-soluble gas, a water amount greater than humidification is dropped and sprayed. You may make it do.

  (4) The above-described embodiments 1 to 3 can be appropriately combined. That is, it is good also as a structure which selects humidity based on the value of the densitometer G in 2nd Embodiment.

  (5) The above embodiment is particularly effective when the concentration of a water-soluble gas having a low concentration (5 ppm or less) is further reduced. However, it is possible to remove water-soluble gas having a concentration of 5 ppm or more. Practically, when removing high concentration water-soluble gas, such as 1000 ppm, it is possible that water-soluble gas adheres to the internal structure of the air conditioner A. In order to cope with this, a configuration may be adopted in which a water-soluble gas is cleaned by providing a cleaning nozzle upstream of each component.

A Air Conditioner C Control Device S Target Space T Thermometer H Hygrometer G Densitometer 1 Chamber 1a Gas Inlet 1b Gas Outlet 1c Outside Air Inlet 2 Prefilter 3 Medium Performance Filter 4 Cooling Coil 4a Cooling Water Supply Line 4b Valve 5 Heating coil 5a Heat source supply line 5b Valve 6 Humidifier 6a Humidified steam supply line 6b Valve 7 Blower 8 Humidifier 10a Exhaust port 10b Air supply port 10c Ventilation port 20 Input unit 30 Output unit 40 Humidity control unit 41 Humidity storage unit 41a Cooling Humidity storage section 41b Humidification humidity storage section 42 Humidity comparison section 42a Cooling humidity comparison section 42b Humidification humidity comparison section 43a Cooling condition determination section 43b Humidification condition determination section 44a Cooling coil control means 44b Humidifier control means 44c Humidifier control means 45 Humidity selection 45a Cooling humidity selection unit 45b Humidification humidity selection unit 50 Temperature control unit 51 Temperature Storage unit 52 temperature comparing unit 53 heating condition determining unit 54 heating coil control unit

Claims (12)

A gas removal method for removing water-soluble gas contained in the gas in the target space using an air conditioner connected to the target space,
The air conditioner has a cooling coil and a humidifier,
Let the air conditioner simultaneously perform cooling by the cooling coil and humidification by the humidifier, and form a water film on the cooling coil by the humidification,
A gas removal method, wherein a gas in the target space is brought into contact with the water film, and a water-soluble gas contained in the gas is dissolved in the water film. The air conditioner further includes a heating coil,
In addition to cooling by the cooling coil and humidification by the humidifier,
2. The gas removal method according to claim 1, wherein heating by the heating coil is performed simultaneously, and the temperature of the target space is set to a predetermined temperature or higher.   3. The gas removal method according to claim 1, wherein humidification is performed on the cooling coil by the humidifier from an upstream side of the cooling coil. Measure the water-soluble gas concentration in the target space,
The gas removal method according to any one of claims 1 to 3, wherein the amount of the water film is adjusted based on the measured water-soluble gas concentration. Measuring the temperature and humidity of the target space,
Based on the measured humidity value, control the cooling coil and the humidifier,
The gas removal method according to any one of claims 2 to 4, wherein the heating coil is controlled based on a measured temperature value. An air conditioner connected to the target space; and a control device connected to the air conditioner, wherein the gas removal system removes water-soluble gas contained in the gas in the target space,
The air conditioner has a cooling coil and a humidifier,
The controller is
Let the air conditioner simultaneously perform cooling by the cooling coil and humidification by the humidifier, and form a water film on the cooling coil by the humidification,
A gas removal system, wherein a gas in the target space is brought into contact with the water film, and a water-soluble gas contained in the gas is dissolved in the water film. The air conditioner further includes a heating coil,
The controller is
In addition to cooling by the cooling coil and humidification by the humidifier,
The gas removal system according to claim 6, wherein the heating coil is further heated at the same time so that the temperature of the target space is equal to or higher than a predetermined temperature.   The gas removal system according to claim 6 or 7, wherein the humidifier is a humidifier disposed on the upstream side of the cooling coil. A water-soluble gas concentration meter provided in the target space is connected to the control device,
The controller is
The gas removal system according to any one of claims 6 to 8, wherein an amount of the water film is adjusted based on a value of the densitometer. A thermometer and a hygrometer provided in the target space are connected to the control device,
The controller is
Controlling the cooling coil based on one of the values of the thermometer and the hygrometer;
10. The heating coil and the humidifier are controlled based on values of the thermometer and the hygrometer in the target space after the cooling coil is controlled. 10. Gas removal system. An air conditioner connected to a target space and having a cooling coil and a humidifier,
Cooling by the cooling coil and humidification by the humidifier are simultaneously performed, and a water film is formed on the cooling coil by the humidification.
An air conditioner characterized in that a gas in the target space is brought into contact with the water film, and a water-soluble gas contained in the gas is dissolved in the water film. The air conditioner according to claim 11, wherein the humidifier is a water humidifier arranged on the upstream side of the cooling coil.