JP7550577B2 - Dehumidification system - Google Patents

Description

The present invention relates to a dehumidification system that dehumidifies air and supplies it to a specified space.

For example, when it comes to painting vehicle bodies such as automobiles, this has traditionally been done in a dedicated painting room with regulated temperature and humidity, in consideration of the deterioration of the working environment in the painting room known as a paint booth and the deterioration of paint quality due to paint mist.

In order to maintain the temperature and humidity in a given space such as a paint booth within a desired range, it is common to use a cooler to lower the air temperature and remove moisture from the air, and then heat the air with a heater to raise its temperature, but this requires a lot of cooling and heating energy.

For this reason, in the past, some of the humid air exhausted from a painting booth, where conditioned air is flowed in a fixed direction while painting is performed by spraying paint onto the workpiece, was collected, and the temperature and humidity of the collected humid air was adjusted before being sent back toward the painting booth. To adjust the humidity (dehumidification), some systems use not only dehumidification using a cooler, but also circulating air dehumidification means equipped with a desiccant rotor (Patent Document 1).

JP 2010-121783 A

However, the desiccant rotor mentioned above requires a rotary drive device such as a motor to rotate the rotor, and a heat source to heat the regeneration zone must be located near the desiccant rotor, which means the equipment becomes larger and there is room for improvement.

The present invention was made in consideration of these points, and aims to provide a dehumidification system that can be made smaller than conventional systems and does not require a separate nearby heat source for heating for regeneration.

In order to achieve the above-mentioned object, the present invention provides a dehumidification system that dehumidifies air and supplies it to a specified space, and includes a non-rotating dehumidifier that houses an adsorbent that has stored heat and been dried by exhaust heat in a casing and dehumidifies the air by passing the air through the adsorbent, and extracts a portion of the air from a flow path of raw air to be supplied to the specified space, dehumidifies the air in the dehumidifier and then returns the air to the flow path, mixes the dehumidified air with the remainder of the raw air, and supplies the mixed air to the specified space , and increases the amount of air extracted from the raw air flow path as the adsorption performance of the adsorbent decreases, thereby increasing the proportion of the dehumidified air .

According to the present invention, a non-rotary dehumidifier is provided in which an adsorbent that has been heat-storing and dried by exhaust heat is housed in a casing, and a part of the raw air is extracted from the flow path of the raw air to be supplied to a specified space, dehumidified by the dehumidifier, and then returned to the flow path, the dehumidified air is mixed with the remaining raw air, and the mixed air is supplied to the specified space. Therefore, unlike a rotary dehumidifier such as a desiccant rotor, no rotating device such as a motor is required, and no associated equipment is required. In addition, since a part of the raw air is extracted from the flow path of the raw air and dehumidified, and then mixed with the remaining raw air, the duct and the necessary fan can be made compact compared to the case where the entire amount is dehumidified. Furthermore, since there is no need to provide a heating device for regeneration near the rotor as in the case of a desiccant rotor, the entire system can be made compact. In addition, the added equipment is compact, and as long as it can be connected to the main air conditioning line, there is an advantage in that the installation layout can be freely set.
As the adsorption performance of the adsorbent deteriorates, the amount of air extracted from the raw air flow path is increased to increase the proportion of dehumidified air. Therefore, even if the adsorption performance deteriorates over the course of operating time, the humidity supplied to a specified space can be maintained at a desired value or range by changing the mixing ratio.

It is also possible to have a cooler that cools the air and a heater that heats the air, and supply the mixed air to the specified space after adjusting the temperature and humidity with the cooler and heater. This makes it possible to fine-tune the temperature and humidity even when strict temperature and humidity adjustments are required for the specified space.

The device may have a connection part of an extraction flow path that is connected to the flow path through which the raw air flows and is used to extract a portion of the raw air, and a connection part of a return flow path that is set downstream of the flow path and is used to return the dehumidified air to the flow path, and the outlet of the return flow path may be directed downstream from the connection part of the return flow path within the flow path. The same effect can also be obtained by directing the inlet of the extraction flow path from the connection part to the upstream side, and the raw air is prevented from being mixed and extracted even if it flows back upstream.

By adopting this configuration, even if the connection part of the discharge flow path and the connection part of the return flow path are brought close to each other, it is possible to prevent the dehumidified air from the return flow path from flowing back upstream and being mixed there, and then being discharged again from the discharge flow path.

Furthermore, from a similar viewpoint, a straightening member may be provided in the flow path so that the dehumidified air that flows out from the outlet of the return flow path into the flow path does not flow back upstream within the flow path.

Even if such a straightening member is provided, or the connection part of the discharge flow path and the connection part of the return flow path are brought closer together, it is possible to prevent the dehumidified air from the return flow path from flowing back upstream and being mixed therewith, and then being discharged again from the discharge flow path. In such a case, it may be used in conjunction with the direction of the outlet of the return flow path.

The present invention allows for a smaller size than conventional devices, and eliminates the need to have a separate heat source nearby for regeneration heating.

1 is an explanatory diagram showing a schematic outline of the configuration of a recycling system for an automobile paint booth in which a dehumidification system according to an embodiment is adopted; 2 is a cross-sectional view showing a connection state between a main flow path of an extraction flow path and a return flow path in the dehumidification system of FIG. 1. FIG. 2 is an explanatory diagram showing a schematic outline of the configuration of a dehumidifier in the dehumidification system of FIG. 1 .

The following describes the embodiment. Figure 1 shows an outline of the configuration of an automobile paint booth recycling system 1 to which a dehumidification system D according to the embodiment is applied. This dehumidification system D is configured to supply a mixture of dehumidified air and raw air to an unmanned paint booth 10, which is a specified space.

The unmanned paint booth 10 is connected to the manned paint booth 20. The unmanned paint booth 10 and the manned paint booth 20 are areas for applying paint to the automobile body 2 within the booth, and after the primary coating is applied in the manned paint booth 20, the secondary coating is applied in the unmanned paint booth 10. In both booths, a water spray shower for mist recovery is implemented to recover floating paint mist.

In order to maintain the atmosphere in both the unmanned painting booth 10 and the manned painting booth 20 at a specified temperature and humidity, the temperature and humidity are monitored by temperature sensors 11, 21 and humidity sensors 12, 22. Temperature and humidity signals from each of these sensors are output to the control device C, which will be described later. As described above, the painting line to which this embodiment is applied has a manned painting booth 10 and an unmanned painting booth 20, but of course the painting line to which this invention is applied can be any type of painting booth, whether manned or unmanned.

The manned painting booth 20 where the first coating is performed is supplied with supply air whose temperature and humidity have been adjusted by a separately installed air conditioner (not shown) through a flow path 23 such as a duct. The humid air exhausted from the manned painting booth 20 is then discharged outside the booth through the main flow path 24, and is then mixed with air dehumidified by a dehumidifier 40 of the dehumidification system D described below, and supplied to the unmanned painting booth 10. The exhaust of air from the manned painting booth 20 and the supply of air to the unmanned painting booth 10 are performed by, for example, two fans 25, 26 installed in the main flow path 24.

The dehumidification system D according to the embodiment is configured to extract a portion of the exhaust air from the manned painting booth 20, which serves as raw air, from the main flow path 24, dehumidify the extracted raw air, and then return it to the main flow path 24. The dehumidification system D is described in detail below.

The dehumidification system D has an extraction flow path 31 (hereinafter sometimes simply referred to as flow path 31) consisting of ducts, piping, etc. for extracting a portion of the raw air from the main flow path 24, and a return flow path 32 (hereinafter sometimes simply referred to as flow path 32) for returning the air after dehumidification by the dehumidifier 40 to the main flow path 24. Flow path 31 is provided with a flow meter 33, a fan 34 for extracting a portion of the raw air from the main flow path 24 and supplying it to the dehumidifier 40, and a thermometer/hygrometer 35, and flow path 31 is connected to the inlet side of the dehumidifier 40. The fan 34 can be inverter controlled.

One end of the flow path 32 is connected to the outlet side of the dehumidifier 40. A thermometer/hygrometer 36 and a filter 37 are provided in the flow path 32. The other end of the flow path 32 is connected to the main flow path 24. The specific connection is as shown in FIG. 2. That is, the extraction flow path 31 is normally connected to the main flow path 24, but the outlet 32a of the return flow path 32 enters the main flow path 24 and faces the downstream side of the main flow path 24.

The dehumidifier 40 has the configuration shown in FIG. 3. That is, the dehumidifier 40 has a filling section 42 in which the space between the upper and lower sections is divided by a partition plate with air permeability, such as a member with air permeability, such as punched metal, and the space between the upper and lower sections is filled with adsorbent M. An upper space 43 and a lower space 44 are formed above and below the filling section 42. Meanwhile, the flow path 31 is branched into two, upper and lower, and divided into branch flow paths 31a and 31b. The branch flow path 31a is connected to the upper space 43, and the branch flow path 31b is connected to the lower space 44. The branch flow paths 31a and 31b are provided with corresponding valves 31c and 31d.

One end of the flow path 32 branches into two, upper and lower, branch flow paths 32a and 32b. The branch flow path 32a is connected to the upper space 43, and the branch flow path 32b is connected to the lower space 44. The branch flow paths 32a and 32b are provided with corresponding valves 32c and 32d.

With the above configuration, the raw air flowing from the extraction flow path 31 can be introduced into the upper space 43 or the lower space 44 by switching the valves 31c and 31d, while the air in the upper space 43 or the lower space 44 can be led into the return flow path 32 by switching the valves 31c and 31d.

This allows the raw air flowing from the extraction flow path 31 to be introduced into the upper space 43, passed through the adsorbent M for dehumidification, and then discharged from the lower space 44 to the return flow path 32, or the flow can be reversed and the raw air flowing from the extraction flow path 31 can be introduced into the lower space 44, passed through the adsorbent M for dehumidification, and then discharged from the return flow path 32 via the upper space 43.

In the embodiment, for example, a granulated adsorbent is used as the adsorbent M. This adsorbent may be a known adsorbent such as silica gel or zeolite, and the granulated adsorbent having the desired performance such as ventilation resistance or heat/mass transfer may be used as an adsorbent having a heat storage function. In such a case, a composite of amorphous aluminum silicate and low-crystalline clay, such as HASClay (registered trademark) or a low-temperature regenerated adsorbent of a polymer adsorbent, can adsorb water vapor in a wide humidity range compared to conventional adsorbents (silica gel, zeolite, etc.), and is suitable for the present invention as an adsorbent having a high-density heat storage function.

In such a case, it is preferable that the dehumidification and heating capacity of the adsorbent M is greater than the dehumidification capacity of the cooler 50 and the heating capacity of the heater 60 described below in terms of the ability to adjust the temperature and humidity of the air to be supplied to the unmanned painting booth 10 to the required level. This reduces the energy input to the cooler 50 and heater 60 when adjusting the air to be supplied to the unmanned painting booth 10 to the required level, thereby improving energy saving effects.

It is also preferable that the adsorbent M is preliminarily stored with heat and dried before the dehumidifier D is installed in the paint booth recycling system 1. That is, the dehumidifier 40 has a simple configuration in which the adsorbent M is filled in a casing 41 that does not have a rotating drive device such as a motor, so that it is easy to install in the paint booth recycling system 1 and can be transported by vehicle or the like. Therefore, for example, the adsorbent M can be heated, stored with heat, and dried in a location away from the paint booth, and then installed in a predetermined position in the paint booth recycling system 1. In addition, since the adsorbent M can be stored with heat and dried in a location away from the paint booth, for example, in a location where exhaust heat is generated, such as a factory, the adsorbent M can be heated, stored with heat, and dried using the exhaust heat, resulting in an extremely high energy-saving effect. The heat source is not limited to such exhaust heat, and may be solar heat, for example.

Of course, if there is a heat source such as exhaust heat near the paint booth, after installing the dehumidifier 40, heat can be supplied from the heat source near the paint booth to the adsorbent M contained in the dehumidifier 40 via a duct or the like to store heat, dry it, and perform the adsorption function.

The aforementioned discharge flow path 31 and return flow path 32 are connected between the filters 27 and 28 provided in the main flow path 24. A temperature sensor 29 is also provided on the outlet side of the fan 25.

Downstream of the connection of the return flow passage 32 to the main flow passage 24, there is a cooler 50 that cools the air flowing through the main flow passage 24, and a heater 60 that heats the air whose temperature has been lowered by the cooler 50.

In this embodiment, the cooler 50 is a cooling coil, and cooling water is introduced into the cooling coil from a supply pipe 52 by a pump 51, and after heat exchange with the air in the main flow path 24, it is returned to a cooling water source (not shown) from a return pipe 53. A temperature sensor 54 is provided on the inlet side of the supply pipe 52, and a temperature sensor 55 is provided on the outlet side of the return pipe 53.

The heater 60 is a heating coil, and for example, hot water is introduced into the heating coil from a supply pipe 62 by a pump 61, and after heat exchange with the air in the main flow path 24, it is returned to a hot water source (not shown) from a return pipe 63. A temperature sensor 64 is provided on the inlet side of the supply pipe 62, and a temperature sensor 65 is provided on the outlet side of the return pipe 63.

The air, whose temperature and humidity have been adjusted through the cooler 50 and heater 60, is then supplied to the unmanned painting booth 10 by the fan 26 through the main flow path 24. The atmosphere inside the unmanned painting booth 10 is exhausted to the outside of the system through the exhaust flow path 72 by the exhaust fan 71.

The control device C is configured to control various members and devices in the dehumidification system D. For example, it can control the air volume of the fans 25, 26, and 34, switch the valves 31c, 31d, 32c, and 32d, control the temperature of the cooler 50, and control the temperature of the heater 60. In addition, the control device C is configured to control the above-mentioned members and devices based on a combination of data from the temperature sensor 11 and humidity sensor 12 in the unmanned painting booth 10, the temperature sensor 29 in the main flow path 24, the flow meter 33 in the extraction flow path 31, the thermometer and hygrometer 35, and the thermometer and hygrometer 36 in the return flow path 32, as indicators for control. In such cases, PID control and feedforward control are performed according to the conditions and the control target.

The dehumidification system D according to the embodiment and the recycling system 1 for automobile paint booths that employs the dehumidification system D are configured as described above, and the automobile body 2 to be painted is first painted in a manned paint booth 20, and then transferred to an unmanned paint booth 10 for secondary painting.

The air exhausted from the unmanned painting booth 10 is cold and humid due to the sprayed paint recovery mist. This cold and humid air (raw air) flows through the main flow path 24 and is first purified by the filter 27. Then, as shown in Figure 2, a portion of the purified air passes through the extraction flow path 31 and is supplied to the dehumidifier 40.

In the dehumidifier 40, as shown in FIG. 3, the low-temperature, humid air (raw air) sent from the flow path 31 is introduced, for example, into the upper space 43, passes through the adsorbent M filled in the filling section 42, and flows into the lower space 44. At this time, the adsorbent M filled in the filling section 42 has stored heat and been dried in advance, so the moisture in the low-temperature, humid air is removed and the temperature is raised. The air dehumidified by the adsorbent M in this way is purified through the filter 37, and then returned to the main flow path 24, where it is mixed with the low-temperature, humid air after a portion of it has been blown out.

At this time, the discharge flow path 31 is connected to the main flow path 24 in the normal way, but the outlet 32a of the return flow path 32 enters the main flow path 24 and faces the downstream side of the main flow path 24. Therefore, even if the discharge flow path 31 and the return flow path 32 are connected to the main flow path 24 in close proximity, the dehumidified air flowing from the flow path 32 does not flow back upstream and mix with the low-temperature, humid air. Therefore, the connection parts of the discharge flow path 31 and the return flow path 32 to the main flow paths 24 can be brought close to each other. For example, the distance L between the discharge flow path 31 and the return flow path 32 shown in FIG. 2 can be shortened.

This allows the ducts and piping of the extraction flow path 31 and the return flow path 32 for the main flow path 24 to be made compact. In addition, combined with the configuration of the non-rotating dehumidifier 40 described above, the dehumidification system D itself can be made compact. Therefore, it is easy to apply this to existing facilities.
Furthermore, while a dehumidifier equipped with a conventional cooling coil or desiccant rotor would require a certain scale to significantly reduce humidity, in this embodiment, the dehumidification-related equipment required for the recycle system 1 is extremely compact. In other words, in the case of a conventional cooling coil, the coil itself would need to be increased in size, and in the case of a desiccant rotor, there is the issue of mixed flow, and it was necessary to significantly increase the size in order to reduce pressure loss to the heat storage material. In contrast, in this embodiment, the dehumidification efficiency is higher than in the past, so the equipment scale can be significantly reduced, making it possible to make it much more compact than these conventional equipment.

In addition, a straightening member such as a straightening plate or a baffle plate may be provided in the main flow path 24 so that the dehumidified air that flows out from the outlet 32a of the return flow path 32 into the main flow path 24 does not flow back upstream in the main flow path 24. By providing such a straightening member, even if the extraction flow path 31 and the return flow path 32 are close to each other, it is possible to prevent the dehumidified air from the return flow path 32 from flowing back and mixing with the low-temperature and humid air that is the raw air upstream of the extraction flow path 31. In addition, by shortening the distance L between the extraction flow path 31 and the return flow path 32, it is possible to make the ducts and piping around the extraction flow path 31 and the return flow path 32 relative to the main flow path 24 compact. Of course, a straightening member may be added to the example shown in FIG. 2.

The high-temperature, low-humidity air flowing from the return flow path 32 and the low-temperature, high-humidity raw air are mixed in the main flow path 24, and then the humidity is adjusted by the cooler 50. The temperature is then adjusted by the downstream heater 60. The air that has been temperature and humidity adjusted in this manner is supplied to the unmanned painting booth 10 by the fan 26. In this embodiment, a separate fan 26 is provided downstream of the fan 25, so that the low-temperature, high-humidity air, which is the raw air, and the high-temperature, high-humidity air after dehumidification can be mixed in the main flow path 24. Therefore, the air supplied to the unmanned painting booth 10 is an air supply without any bias in temperature and humidity, which is suitable for painting in the booth.

Due to its nature, the adsorbent M contained in the dehumidifier 40 may lose its adsorption performance over the course of operation. To address this issue, the dehumidification system D according to this embodiment can take measures such as the following:

[Flow path switching]
For example, as shown in Fig. 3. At the beginning of operation, the raw air partially extracted from the main flow path 24 was made to flow from the upper space 43 to the lower space 44 in the dehumidifier 40, passing through the adsorbent M, but because the adsorbent M is stacked in layers, the performance degradation is greater closer to the upper space 43, and the performance degradation is smaller on the side closer to the lower space 44. Therefore, the performance degradation can be addressed by switching the inlet side valves 31c, 31d and the outlet side valves 32c, 32d to introduce the raw air from the lower space 44, pass the adsorbent M, and flow into the upper space 43.

[Changes in Mixing Ratio]
When the adsorption performance of the adsorbent M decreases, the absolute humidity after mixing can be maintained within a predetermined range by extracting an amount of raw air from the main flow path 24 accordingly, dehumidifying a larger amount of air, and changing the mixing ratio when returning the air from the return flow path 32 to the main flow path 24 and mixing it. In other words, as the adsorption performance of the adsorbent M decreases, the amount of air extracted from the extraction flow path is increased to increase the amount of air to be dehumidified, and the mixing ratio with the raw air after cooking is changed (increasing the proportion of extracted and dehumidified air), thereby compensating for the decrease in the adsorption performance of the adsorbent M.

Such a control of the mixture ratio can be easily realized, for example, by inverter control of the extraction fan 34. In addition, such a control can be performed, for example, by controlling the absolute humidity based on the detection results of the thermometer and hygrometer 35, 36.
It is proposed to perform feedforward control on the fan 34 and then perform PID control for subsequent adjustment.

The dehumidification system D according to the embodiment described above is applied to an unmanned paint booth 10 as the specified space, and uses exhaust air from a manned paint booth 20 as the raw air, but the present invention is not limited to this and can be applied to other spaces. For example, in a large-scale clean room in a semiconductor manufacturing factory, in a process that requires humidity control, the raw air may be returned from the clean room, and a portion of the air may be extracted, dehumidified, and mixed with the return air. In this case, high-performance filters may be used for the filters 27, 28, and 37.

In addition, for spaces where humidity and temperature control are particularly strict, such as pharmaceutical manufacturing plants, food factories, and printing factories, a portion of the return air or exhaust air from the space may be extracted and dehumidified, and then mixed with the return air or exhaust air and supplied to the space.

This invention is useful for air conditioning spaces that require humidity control, such as in factories.

REFERENCE SIGNS LIST 1 Paint booth recycling system 2 Automobile body 10 Unmanned paint booth 20 Manned paint booth 24 Main flow path 25, 26, 34 Fan 27, 28, 37 Filter 31 Extraction flow path 32 Return flow path 33 Flow meter 35, 36 Thermo-hygrometer 40 Dehumidifier 41 Casing 50 Cooler 60 Heater C Control device D Dehumidification system M Adsorbent

Claims (4)

A dehumidification system that dehumidifies air and supplies the dehumidified air to a specified space,
The dehumidification device includes a non-rotating dehumidification device that contains an adsorbent that has been dried by storing heat through exhaust heat in a casing and that dehumidifies the air by passing the air through the adsorbent,
extracting a portion of the raw air from a flow path for supplying the raw air to the predetermined space, dehumidifying the air in the dehumidifier, and then returning the air to the flow path, and mixing the dehumidified air with the remaining raw air;
The mixed air is supplied to the predetermined space ,
a rate of the dehumidified air being increased by increasing the amount of air extracted from the flow path of the raw air as the adsorption performance of the adsorbent decreases. The air conditioner has a cooler that cools air and a heater that heats air,
2. The dehumidification system according to claim 1, wherein the mixed air is supplied to the predetermined space after temperature and humidity are adjusted by the cooler and the heater. a connection part for an extraction flow path that is connected to a flow path through which the raw air flows and is for extracting a portion of the raw air; and a connection part for a return flow path that is set downstream of the flow path and for returning the dehumidified air to the flow path,
The dehumidification system according to any one of claims 1 to 2 , characterized in that an outlet of the return flow passage is directed downstream from a connection portion of the return flow passage within the flow passage. a connection part for an extraction flow path that is connected to a flow path through which the raw air flows and is for extracting a portion of the raw air; and a connection part for a return flow path that is set downstream of the flow path and for returning the dehumidified air to the flow path,
4. The dehumidification system according to claim 1, further comprising a straightening member provided in the flow path so that the dehumidified air that has flowed out from the outlet of the return flow path into the flow path does not flow back upstream within the flow path.

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