JPS62277174A - Painting booth - Google Patents

Abstract

PURPOSE:To recover the waste heat from a painting operation area and to reduce an energy loss by evaporating the cleaning liquid after cleaning in a paint mist removing device and subjecting the evaporated cleaning liquid and a heat medium for recovering heat to a heat exchanger. CONSTITUTION:The painting scum of the cleaning liquid W after said liquid is used for the cleaning operation from the paint mist removing device of a booth for painting automobile bodies, castings of electrical household appliances, etc., is separated and is supplied to a heat exchanger 24. The heat exchanger 24 is provided with a carbureter part to evaporate the cleaning water W and a condenser part to deprive the evaporated water W of the condensation heat. The circulating heat medium liquid of a preheating coil 16 of an air conditioner 3 and the evaporated cleaning liquid W are subjected to the heat exchange by the heat exchanger 31 in the condenser part. The waste heat from the painting operation area is thus extremely satisfactorily recovered with high efficiency for a long period of time, by which the energy loss is additionally effectively reduced.

Description

[Detailed Description of the Invention] 3. Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a painting booth for painting automobile bodies, casings of home appliances, etc. The present invention relates to a painting booth equipped with an air conditioner that controls the temperature of supplied ventilation gas, and a paint mist removal device that captures and removes paint mist in the exhaust gas by bringing the exhaust gas from the painting work area into contact with a cleaning liquid.

[Conventional technology]

Conventionally, in order to suppress energy loss by recovering the waste heat carried out of the system together with the exhaust gas from the painting work area in the above-mentioned painting booth, the cleaning solution was circulated in the paint mist removal device, and then As shown in Figure 5, there is a total heat exchanger (1) that preheats the outside air taken in by exchanging heat between the exhaust gas that has passed through the paint mist removal device (8) and the outside air taken into the air conditioner (3). 36), or, as shown in Figure 6, a heat pump (35) is installed that uses the exhaust gas that has passed through the paint mist removal device (8) as a heat receiving source, and the heat pump (35) performs air conditioning. Vessel (3)
The heating medium liquid for the temperature control coil (16) was heated.

In other words, the most direct way to recover waste heat from the painting work area is to recover the amount of heat retained in the exhaust gas before it passes through the paint mist removal device, but in the paint mist removal device, the cleaning fluid is circulated using a circulation pump. If used, under steady-state operating conditions, the circulating cleaning fluid will reach an equilibrium state due to contact with the exhaust gas, with a temperature as close as possible to the ventilation gas dew point temperature in the painting work area, thus preventing the painting work from occurring. Even after passing through the paint mist removal device, most of the exhaust heat from the area remains retained in the exhaust gas as the amount of heat retained in the exhaust gas.

In other words, sufficient heat can be recovered even from the exhaust gas that has passed through the paint mist removal device, and paint mist has also been removed from the exhaust gas that has passed through the paint mist removal device, making it possible to recover sufficient heat from the exhaust gas that has passed through the paint mist removal device. From the viewpoint of suppressing adhesion and accumulation of paint mist, as mentioned above, the exhaust gas after passing through the paint mist removal device and the heat medium for exhaust heat recovery (heat medium liquid for intake outside air, temperature control coil, etc.) The waste heat was recovered by exchanging heat (I can't provide any literature).

[Problem that the invention seeks to solve]

However, even though the paint mist is removed by contact with the cleaning liquid, a considerable amount of fine paint mist still remains in the exhaust gas after passing through the paint mist removal device. However, due to its high stickiness, the paint mist remaining in the exhaust gas can adhere to and accumulate on exhaust heat recovery heat exchangers (total heat exchangers for external air, heat exchangers on the heat receiving side of heat pumps, etc.). Therefore, there is a problem in that the heat exchange efficiency (that is, the exhaust heat recovery efficiency) decreases significantly, making it impossible to achieve sufficient exhaust heat recovery.

The purpose of the present invention is to move away from the conventional concept of recovering exhaust heat directly from exhaust gas, and to eliminate the adhesion of paint mist through rational exhaust heat recovery that focuses on removing paint mist through contact between exhaust gas and cleaning fluid. The object of the present invention is to effectively avoid a decrease in exhaust heat recovery efficiency due to deposition, further improve the exhaust heat recovery efficiency itself, and downsize the exhaust heat recovery structure.

[Means for solving problems]

The characteristic configuration of the painting booth according to the present invention is that it is equipped with a paint mist removal device that removes paint mist from the exhaust gas by bringing the exhaust gas from the painting work area supplied with temperature-controlled ventilation gas into contact with the cleaning liquid. A vaporizer is installed to form a low-pressure space for evaporating the cleaning liquid after the cleaning action has been performed by the paint mist removal device, and the vaporized cleaning liquid is exchanged with the heat recovery heat medium in the vaporizer to remove the vaporized cleaning liquid. A heat exchanger is provided to recover waste heat from the painting area by removing condensation heat, and its functions and effects are as follows.

[For production]

In other words, the contact between the exhaust gas and the cleaning liquid for paint mist removal is used for direct heat exchange in which the exhaust gas transfers waste heat to the cleaning liquid, and the exhaust heat transferred to the cleaning liquid through the direct heat exchange is recovered with the cleaning liquid. It is recovered from the cleaning liquid through heat exchange with the heat transfer medium.

At that time, the cleaning liquid after the cleaning action contains paint slag captured from the exhaust gas, but the cleaning liquid is evaporated in the low-pressure space of the vaporizer, and heat exchange between the evaporated vaporized cleaning liquid and the heat recovery heat medium is performed. Since the condensation heat of the vaporized cleaning liquid is given to the heat recovery heat medium and the waste heat is recovered, in other words, the cleaning liquid is once vaporized and the waste heat is recovered from the vaporized cleaning liquid, so paint slag in the cleaning liquid will adhere to the heat exchanger. This is very effectively avoided.

Furthermore, when using a gas such as intake outside air as a heating medium for heat recovery, the conventional method involves gas-to-gas heat exchange, but according to the present invention, heat exchange occurs between gas and low-pressure vaporized liquid. In addition, when using a heat medium liquid as a heat medium for heat recovery, the heat exchange is between liquid and gas in the conventional type, but according to the present invention, heat exchange is between liquid and low-pressure vaporized liquid. Regardless of whether the heat recovery medium is a gas or a liquid, the heat exchange efficiency itself can be improved and the heat exchange configuration can be downsized compared to conventional types.

The above-mentioned effects occur in both types of paint mist removal equipment, such as those that temporarily consume the cleaning liquid and those that use it recirculatingly. By recovering exhaust heat from the cleaning fluid, the exchange of exhaust heat through direct heat exchange between the circulating cleaning fluid and the exhaust gas continues.

〔Effect of the invention〕

As a result of the above, waste heat from the painting area can be recovered with high efficiency over a long period of time, making it possible to more effectively reduce energy loss compared to conventional equipment, and in turn, significantly reducing running costs. I was able to achieve this.

Furthermore, by making the heat exchanger structure more compact, the ease of installing the paint booth can be improved, which is also advantageous in terms of effective use of space in paint factories and the like.

[First example] Next, a first embodiment of the present invention will be described.

Figure 1 shows the overall configuration of the painting booth, and shows the painting robot (
An air conditioner (
Air outlet (4) that blows out the temperature-controlled ventilation air from (3) downward.
), and the floor is formed with a lattice-structured exhaust port (5), and as ventilation air is supplied from the outlet (4), excess spray paint mist in the work area (2) is removed together with the air within the area. It should be discharged from (5).

In the figure (A) there is an object to be coated.

A cleaning water flow tank (6) is provided below the floor with a grid structure to catch fallen paint lumps and exhaust air from the work area (2), and also to prevent overflow from the cleaning water flow tank (6). A curved constriction channel (7
This constitutes a paint mist removal device (8) that captures and removes paint mist in the exhaust air by bringing the exhaust air into contact with cleaning water (W).

The exhaust air that has passed through the paint mist removal device (8) is exhausted to the outside of the system via an exhaust fan (9).

In the figure, (10) is a water tank that receives the washing water flowing down from the bent constriction channel (7), and the washing water (W) received in the water tank (10) is transferred to the paint slag separator (11), Further, after being supplied to a storage tank (13) equipped with a separation paint sludge scraper (12) and purified, it is again circulated and supplied to the washing water lower tank (6) by a circulation pump 27).

On the other hand, the air conditioner (3) includes a prefilter (15), a preheating coil (16), a humidifier (17), and a cooling coil (18).
, and a reheating coil (19), and the outside air taken in from the outside air intake (20) is treated with dust removal by the air conditioner (3).
After being subjected to temperature control processing and humidity control processing, it is supplied as ventilation air to the outlet (4) by the air supply fan (21).

In the figure, (22) is a cold heat source device that circulates and supplies low-temperature refrigerant such as cold water or brine to the cooling coil (18), and (23) is a cold heat source device that supplies hot water, steam, etc. to the reheating coil (19). This is a heat source device that circulates and supplies high-temperature heat medium.

In addition, in this painting booth, exhaust heat loss is suppressed by recovering the exhaust heat taken out with the exhaust air from the painting work area (2) and reusing the recovered heat as part of the heat for air conditioning. The system is designed to reduce the energy required for air conditioning, and the specific exhaust heat recovery structure is a heat exchange device that pumps up the heat retained in the wash water (W) by using the evaporation and condensation of the wash water (W). (24) is provided, and the cleaning water (W) is taken out from the downstream side of the paint slag separator (11) in the cleaning water storage tank (13), and the extracted cleaning water (-)
A pump (25) is provided to supply water to the heat exchanger (24), and on the other hand, the amount of heat pumped up from the wash water (W) is used to heat the circulating heat medium liquid for the preheating unit 16) of the air conditioner (3). A heat exchange device (24) is interposed in the heat medium circulation path (26) for the preheating coil (16).

In other words, the contact between the exhaust air and the cleaning water (W) in the paint mist removal device (8) is used for direct exchange of exhaust heat from the exhaust air to the cleaning water tip. The heat exchanger (24) pumps up the waste heat given to the air conditioner (3) using the pumped waste heat as a heat source.
This is to preheat the outside air taken in.

In the heat exchanger (24), the retained waste heat is transferred to the preheating coil (1
The cleaning water flow after being applied to the circulating heat transfer liquid in step 6) is again supplied to the cleaning water flow lower tank (6) by the pump (27).

The heat exchange device (24) is functionally equipped with a vaporizer part that evaporates the cleaning water (X) and a condenser part that takes condensation heat from the evaporated vaporized cleaning water (A). The structure consists of an airtight container (2
8), and a vacuum pump (29) that makes the inside of the closed container (28) a low-pressure space for evaporating the washing water, and furthermore, a vacuum pump (29) is provided to make the inside of the sealed container (28) a low-pressure space for evaporating the washing water (-) from the washing water storage tank (13). A spout (30) is provided to cause the water to overflow in the form of a fountain.

In addition, as for the configuration of the condenser part, as the circulating heat medium liquid flows in the pipe for the preheating coil (16) of the air conditioner (3), heat is exchanged between the circulating heat medium and the vaporized cleaning liquid (-). The exchanger (31) is disposed in the upper part of the closed container (28).

In other words, the cleaning water (-) is evaporated by ejecting the cleaning water tip in a low-pressure space, and the vaporized cleaning water (W) is condensed by heat exchange with the heat transfer liquid. This is to impart heat to the heat transfer liquid.

In addition, using the evaporation and condensation of the washing water (W), the washing water (W)
By recovering exhaust heat from the Totohe storage tank (
Washing water (W) supplied from 13) to the heat exchanger (24)
) contains fine paint particles that have passed through the paint slag separator (11), the paint particle heat exchanger (31)
) is almost certainly prevented, and the thermal efficiency of the heat exchanger (31), that is, the exhaust heat recovery efficiency, is maintained at an extremely high level.

In the figure (32) is an eliminator.

In this example, the preheating coil (16) is placed upstream of the humidifier (17) in the intake outside air flow path in the air conditioner (3).
By arranging the humidifier (17) further downstream and spraying the spray water from the humidifier (17) onto the preheating coil (16), the preheating coil (16) can perform not only sensible heat exchange but also latent heat exchange. By doing so, the overall heat transfer coefficient of the preheating coil (16) is increased to improve waste heat utilization efficiency, and
In addition to downsizing the preheating coil (16), the heat exchanger (31) that condenses the vaporized cleaning water can have a large effective temperature difference, thereby further improving the exhaust heat recovery efficiency and improving the heat exchange. The container (31) may be made smaller.

In addition, when both sensible heat exchange and latent heat exchange are performed in the preheating coil (16), the humidifying water is transferred to the preheating coil (16).
Instead of spraying humidifying water onto a preheating coil (1
6) may be configured such that it is dropped.

[Second example] Next, a second embodiment of the present invention will be described.

In a painting booth having almost the same configuration as the one shown in FIG. 1 explained in the first embodiment, the evaporation and condensation of the cleaning water (W) is used to reduce the amount of heat retained in the cleaning water (W) (i.e., in the painting work area). (2) Heat exchange device (24) that recovers waste heat from
As shown in Fig. 2, the lower cylindrical container (
28A) is equipped with a cleaning water sprayer (30) to form a vaporizer, and the lower cylindrical container (28A) on the vaporizer side is
) A heat exchanger (3
1) to constitute a condenser, and a plurality of heat exchange units (24A) each consisting of a pair of a vaporizer and a condenser.

(24B) and (24C), and their Uni-Soto (2
4A), (24B).

The vaporizers of (24C) are connected in series in the wash water supply path, and these units (24A).

(24B), (24C) condenser side heat exchange! #,vessel(
31) The units are connected in series and arranged in parallel in the heat medium circulation path (26) for the preheating coil (16) of the air conditioner (3), and each unit (24A), (24B),
A vacuum pump (29) is connected to each of the upper cylindrical containers (28B) of (24C).

That is, the exhaust heat from the painting work area (2) is evaporated in the low-pressure space in the vaporizer of the washing water (W) given by contact with the exhaust air in the paint mist removal device (8), and The evaporated cleaning water (W) is transferred to the heat exchanger (31) in the condenser.
), and the condensation heat is transferred to the preheating coil (16).
The exhaust heat recovery is carried out in multiple stages by giving it to the circulating heat transfer liquid, thereby increasing the amount of exhaust heat recovery.

In addition, heat exchange units (24A) were installed in parallel in series.

(24B), (24C>, the flow direction of the cleaning water (W) and the flow direction of the circulating heat medium liquid (W) for the preheating coil are opposite to each other, and a so-called counterflow type heat exchange form is adopted. By doing so, the heat exchange efficiency of each heat exchanger (31), that is, the exhaust heat recovery efficiency is further improved.

[Other Examples]

Next, other examples will be listed.

As shown in Fig. 3, a container (2) connected to a vacuum pump (29) is used as a vaporizer to evaporate the cleaning liquid (W) in a low-pressure space after being cleaned by the paint mist removal device (8).
8) is equipped with a cleaning liquid spraying nozzle (33), and on the other hand, a tube-type heat exchanger that allows the vaporized cleaning liquid (W) to flow through the pipes so as to exchange heat between the vaporized cleaning liquid (W) and a heat medium for heat recovery. (31) to the outside air intake path (34) to the air conditioner (3).
), and by heat exchange between the vaporized cleaning liquid (W) and the intake outside air, the retained waste heat of the cleaning liquid (-) is removed while the vaporized cleaning liquid (W) is compressed as it flows in the pipe. It is also possible to provide air in and out.

Further, as shown in FIG. 4, a heat pump (35) is provided to heat the air conditioning heat medium used in the air conditioner (3), and
A container (2) forming a low pressure space in which the cleaning liquid (W) is evaporated.
8), the heat receiving side heat exchanger (31) of the heat pump (35) is installed inside the heat pump (35).
The vaporized cleaning liquid (W) is condensed through heat exchange between the working heat medium and the vaporized cleaning liquid (for example), and the waste heat retained in the cleaning liquid (W) is pumped up by the heat pump (35), and the pumped waste heat is used as the heat source for air conditioning. You may reuse some of them.

In other words, the heat recovery heat medium to be used for heat exchange with the vaporized cleaning liquid (-) may be an air conditioning heat medium used in the air conditioner (3), outside air taken into the air conditioner (3), or an air conditioning heat medium that heats the air conditioning heat medium. Various types of heating medium, whether gas or liquid, can be used as the operating heating medium for the heat pump (35), and a heating medium for heat recovery can be used so that the waste heat recovered from the vaporized cleaning liquid (-) can be used for purposes other than air conditioning. You may choose.

The specific structure of the vaporizer that forms a low-pressure space for evaporating the cleaning liquid (W) can be improved in various ways, and the vacuum pump (29) may be of a turbo type, a positive displacement type, or a single ejector type. and those that apply chemical effects, etc.
Various types can be applied.

Various types of heat exchangers (31) can be used for exchanging heat between the vaporized cleaning liquid (W) and the heat recovery heat medium.

A nozzle is provided that sprays high-pressure water or clean washing water (xo) onto the inner circumferential surface of the container (28) for forming a low-pressure space that constitutes the vaporizer, and the spraying sprays paint onto the inner circumferential surface of the container (28). It may also be possible to prevent the adhesion and accumulation of.

In addition, if extremely fine paint mist exists in the vaporized cleaning liquid (W) and there is a risk that the fine paint mist may adhere to the heat exchanger (31), the vaporized cleaning liquid (W) in the heat exchanger (31) may High pressure water or cleaning liquid (W) is applied to the condensation part of W).
) is installed at the right time or intermittently.
This may further reliably prevent fine paint mist from adhering to and accumulating on the heat exchanger (31).

It is optional to provide various types of paint sludge separators (11) such as filters for separating and removing paint sludge in advance from the cleaning liquid (W) supplied to the vaporizer.

As the cleaning liquid (-), various liquids other than water can be used. In addition, various paint tack reducing agents such as caustic soda are mixed into the cleaning liquid (W) (this is effective in preventing paint from adhering to the vaporizer).

The temperature-controlled ventilation gas supplied from the air conditioner (3) to the painting work area (2) is not limited to air.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a first embodiment of the present invention. Second
The figure is a configuration diagram showing a second embodiment of the present invention. FIGS. 3 and 4 are configuration diagrams showing other embodiments, respectively. FIGS. 5 and 6 are configuration diagrams showing conventional examples, respectively. (2)...Painting work area, (3)...Air conditioner, (8)...Paint mist removal device, (31
)...Heat exchanger, (W)...Cleaning liquid.

Claims (3)

[Claims] (1) An air conditioner (3) that controls the temperature of the ventilation gas supplied to the painting work area (2), and an air conditioner (3) that controls the temperature of the ventilation gas supplied to the painting work area (2), and a cleaning liquid (W) that brings the exhaust gas from the painting work area (2) into contact with the exhaust gas. A painting booth is equipped with a paint mist removal device (8) that captures and removes paint mist, and forms a low-pressure space for evaporating the cleaning liquid (W) after the cleaning action in the paint mist removal device (8). A vaporizer is installed to remove the heat of condensation from the vaporized cleaning liquid (W) by exchanging heat between the vaporized cleaning liquid (W) and a heat recovery heat medium in the vaporizer, thereby removing the condensation heat from the painting work area (2). Heat exchanger to recover waste heat (31
) painting booth. (2) The painting booth according to claim (1), wherein the heat recovery heat medium is an air conditioning heat medium liquid used in the air conditioner (3). (3) The painting booth according to claim (1), wherein the heat medium for heat recovery is outside air taken into the air conditioner (3).