JPS62254827A - Apparatus for recovering waste heat obtained from exhaust gas treatment apparatus - Google Patents

Abstract

PURPOSE:To effectively utilize the waste heat of deodorized gas by interposing a heater for a heating medium in such a passage that the deodorized gas discharged from a catalytic layer is fed to a heat exchanger therethrough, feeding and circulating the heating medium to a heat recovery apparatus for the heating medium and providing a means controlling the flow rate of the heating medium. CONSTITUTION:Exhaust gas of a drying furnace 1 is sent to a catalytic layer 5 heated by a burner 4 via a heat exchanger 3 by means of a fan 2, and harmful offensive odor components are burned and decomposed. Deodorized gas discharged from the catalytic layer 5 is sent into a heater 7 for a heating medium to heat the heating medium incorporated in finned tubes 8 and then preheats the exhaust gas in a heat exchanger 3. The heating medium is sent to a heat recovery apparatus 10 for the heating medium by a pump 12 for the heating medium and preheats the air incorporated in the furnace which is heated by a burner 27 of a hot air circulation system 9 and it is circulated and sent to the heater 7. In this case, the number of revolutions of the circulation pump 12 is changed by a detection signal sent from a temp. detection sensor 14 and the flow rate of the heating medium is controlled and the preheating temp. of the exhaust gas is definitely maintained.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention is applicable to various exhaust gas generation sources such as painting drying ovens, printing drying ovens, plastic and plywood manufacturing equipment, food processing equipment, and industrial waste processing equipment. The present invention relates to an exhaust heat recovery device from an exhaust gas treatment device that deodorizes exhaust gas discharged from the exhaust gas by passing it through a catalyst layer.

[Prior art and its problems]

In various facilities such as the above-mentioned paint drying ovens, paints, inks, solvents, adhesives, synthetic resins, chemicals, alcohol 9 esters, phenols with toxic and characteristic odors, aldehydes, etc. There are problems such as the generation of harmful and odor components such as harmful odor components that harm the working environment.

For this reason, it is necessary to discharge the exhaust gas containing harmful odor components outside the facility, but from the perspective of pollution prevention, it is not possible to release it directly into the atmosphere, and it is usually done through a catalytic combustion type exhaust gas treatment device to make it harmless and odorless. The plan is to release it in a solidified state.

By the way, a conventional general exhaust gas treatment device for making exhaust gas harmless and odorless is constructed as shown in FIG. 3.

That is, FIG. 3 shows a conventional example of an exhaust gas treatment device that deodorizes exhaust gas discharged from a painting drying oven, which is an exhaust gas generation source. Exhaust gas at 180°C is preheated to about 300 to 350"C through a heat exchanger 3, and sent to a catalyst N5 heated to a predetermined reaction temperature (usually about 350 to 450°C) by a burner 4. The high-temperature deodorized gas that has been deodorized through the layer 5 is sent to the heat exchanger 3, used to preheat the exhaust gas, and then discharged to the outside.

In other words, the exhaust gas sent from the drying furnace 1 to the catalyst layer 5 is preheated by the heat exchanger 3 that recovers the heat of oxidation combustion of harmful malodorous components contained in the exhaust gas, and the fuel consumption of the burner 4 is reduced. We are trying to save money.

However, the exhaust gas that is deodorized by passing through the catalyst layer 5 heated to about 350 to 450'C by the burner 4 has a temperature of about 450 to 520'C due to oxidative combustion of harmful malodorous components contained in the exhaust gas. Since the deodorizing gas is extremely hot, when it is sent to the heat exchanger 3, the preheating temperature of the exhaust gas sent to the catalyst layer 5 through the heat exchanger 3 is set to the reaction temperature of the catalyst layer 5 (deodorization control temperature), the temperature system of the entire device may collapse, and the device may be damaged due to the temperature rise in each part of the device.

Therefore, conventionally, in order to prevent the exhaust gas sent to the catalyst layer 5 from being preheated to an abnormally high temperature by the heat exchanger 3, various measures as listed below have been taken.

(Measure I) Considering that the amount of harmful odor components generated from the coating film of the object to be coated dried in the drying oven 1 is approximately constant, the amount of exhaust gas discharged from the drying oven 1 and sent to the catalyst layer 5 is adjusted. By increasing the temperature, the exhaust gas concentration is relatively lowered and the heat of oxidation combustion of the exhaust gas passing through the catalyst layer 5 is reduced, thereby preventing the temperature of the deodorized gas that has been deodorized through the catalyst rvJ5 from reaching an abnormally high temperature. are doing.

However, increasing the exhaust gas air volume in this way increases the capacity of the fan 2 and burner 4, which increases power costs.

There are problems in that fuel costs increase and at the same time, the overall size of the exhaust gas treatment device increases.

In addition, since a large amount of exhaust gas is sucked and discharged from the inside of the drying furnace 1, low-temperature outside air flows into the drying furnace 1 through the entrance and exit of the drying furnace 1, disrupting the temperature distribution inside the furnace and causing poor heating of the object to be coated. This not only impairs the quality of the product, but also increases the combustion amount of the burner that heats the inside of the drying furnace 1, increasing fuel costs, and increasing the size of the exhaust gas collection duct installed inside the drying furnace 1. There is also a problem in that the equipment cost for the drying equipment increases.

(Measure ■) In addition, the heat recovery efficiency of the heat exchanger 3 is reduced to prevent the exhaust gas from being preheated to an abnormally high temperature without increasing the volume of exhaust gas discharged from the inside of the drying oven 1. However, in this case, the exhaust heat of the deodorized gas cannot be used effectively, and the amount of combustion of the burner 4 that heats the catalyst layer 5 to a predetermined reaction temperature must be increased compared to the conventional one. 4, the burner combustion system of the exhaust gas treatment device becomes larger, resulting in an increase in fuel costs, equipment costs, etc.

(Measure ■) In addition, by introducing a required amount of fresh air from the middle of the passage that feeds the exhaust gas inside the drying furnace 1 to the exhaust gas treatment device as shown in Fig. 3 and mixing it with the exhaust gas, the inside of the drying furnace 1 can be There is also a method that reduces the concentration of exhaust gas without increasing the volume of exhaust gas discharged from the drying furnace 1, thereby preventing the temperature distribution within the drying oven 1 from becoming distorted.

However, in this case as well, there is a problem that the capacity of the fan 2 and the burner 4 becomes large, increasing the power cost and fuel cost, and at the same time, the overall size of the exhaust gas treatment device becomes large.

(Measure ■) Also, when the preheating temperature of the exhaust gas by the heat exchanger 3 rises above a certain level, the combustion of the burner 4 that heats the catalyst layer 5 is stopped, and when the temperature drops to a certain level, the burner 4 is ignited again. Measures have been taken to prevent the deodorizing gas from reaching an abnormally high temperature.However, in this case, the burner 4 must be turned on and off frequently and the operator must check the ignition status each time. In addition to this, there is a problem that when the concentration of exhaust gas oxidized and burned in the catalyst layer 5 is high, the temperature of the deodorized gas does not decrease even if combustion in the burner 4 is stopped.

In addition, if the troublesome work of turning on and off the burner 4 is automated as described above, there is a risk of an accident in which the burner 4 does not ignite and fuel continues to spout due to a failure of the automatic equipment, which is a safety issue. There's a problem.

[Purpose of the invention]

Therefore, the present invention aims to increase the flow rate of exhaust gas sent from an exhaust gas generation source such as a paint drying oven to the catalyst layer of an exhaust gas treatment device through a heat exchanger, and to turn on and heat the catalyst layer.
It is possible to reliably prevent the preheating temperature of the exhaust gas sent to the catalyst layer from reaching an abnormally high temperature without turning it off, and at the same time, it is possible to extremely effectively recover and use the exhaust heat of the deodorized gas that has been deodorized through the catalyst layer. It is an object of the present invention to provide an exhaust heat recovery device from an exhaust gas treatment device that can control the temperature of exhaust heat to be recovered and used to a constant value.

[Structure of the invention]

To achieve this objective, the present invention provides that exhaust gas discharged from an exhaust gas generation source is preheated through a heat exchanger and sent to a catalyst layer heated to a predetermined reaction temperature by a burner, and deodorized through the catalyst layer. The exhaust heat recovery device from the exhaust gas treatment device is configured such that the treated high-temperature deodorized gas is sent to the heat exchanger to preheat the exhaust gas and then discharged to the outside, wherein the catalyst a heating medium heater interposed in a passage for feeding high-temperature deodorized gas deodorized through the layer to the heat exchanger; and a heating medium heated by heat exchange with the deodorizing gas in the heating medium heater. a heat medium circulation system consisting of a heat medium circulation outward path and a heat medium circulation return path for circulating and supplying heat medium to a heat medium heat recovery device; and variably adjusting the flow rate of the heat medium flowing into the heat medium heater through the heat medium circulation return path. It is characterized by comprising a heating medium flow rate control means.

[Action of the invention]

According to the present invention, the high-temperature deodorized gas that has been deodorized through the catalyst layer of the exhaust gas treatment device passes through the heat medium heater of the exhaust heat recovery device and radiates heat by heat exchange with the heat medium, and then the exhaust gas is preheated. Since the exhaust gas is sent to the heat exchanger, it is possible to prevent an abnormal rise in the preheating temperature of the exhaust gas without increasing the amount of exhaust gas sent from the exhaust gas generation source to the catalyst layer or stopping the combustion of the burner that heats the catalyst layer, as in the case of conventional methods. At the same time, a heating medium heated by heat exchange with high-temperature deodorizing gas can be circulated to a drying furnace for painting, for example, or a heating source for pretreatment liquid in a painting pretreatment device, etc. The exhaust heat from the exhaust gas treatment device can be used to its fullest extent and energy can be saved by circulating the heat medium and supplying it to a heat recovery device used for various purposes.

Further, according to the present invention, since the heat medium flow rate control means for variably adjusting the flow rate of the heat medium flowing in the heat medium heater is provided, for example, deodorizing gas sent from the heat medium heater to the heat exchanger is provided. By variably adjusting the heat medium flow rate according to the temperature change of the heat medium and the temperature change of the heat medium sent from the heat medium heater to the heat medium heat recovery device through the heat medium circulation outward path, the exhaust gas in the heat exchanger can be reduced. It is possible to always maintain the preheating temperature and the heat radiation temperature of the heat medium heat recovery device constant.

〔Example〕

Embodiments of the present invention will be specifically described below based on the drawings.

FIG. 1 is a flow sheet diagram showing an example of an exhaust heat recovery device from an exhaust gas treatment device according to the present invention.

Note that parts common to those in FIG. 3 described above are given the same reference numerals, and detailed explanation thereof will be omitted.

The exhaust gas treatment device G shown in FIG. A medium heater 7 is interposed.

A fin tube 8 for circulating the heat medium is disposed in the heat medium heater 7 into which the deodorizing gas is fed, and the heat medium flowing through the fin tube 8 is heated by heat exchange with the deodorizing gas to form a drying device. The hot air is circulated and supplied to a heat medium heat recovery device 10 installed in a hot air circulation system 9.

That is, the heat medium heated by heat exchange with the deodorizing gas is passed through the heat medium heater 7 interposed in the passage 6 of the exhaust gas treatment device G and the fin tube 8 in the heat medium heater 7. An exhaust heat recovery device H is provided, which includes a heat medium circulation system 11 consisting of a heat medium circulation outward path 11a and a heat medium circulation return path 11b that circulate and supply the heat medium to the heat recovery device 10. is configured to be circulated and supplied to the heat medium heat recovery device 10 by a heat medium circulation pump 12 interposed in the heat medium circulation return path 11b of the heat medium circulation system 11.

In addition, the exhaust heat recovery device (1) includes a heat medium flow control means 13 that variably adjusts the flow rate of the heat medium flowing into the fin tube 8 of the heat medium heater 7 through the heat medium circulation return path 11b by the heat medium circulation pump 12. is equipped.

The heat medium flow rate control means 13 includes a temperature detection sensor 14 that detects the temperature of the deodorizing gas sent into the heat exchanger 3 from the heat medium heater 7 through the passage 6 of the exhaust gas treatment device G; Heat medium circulation pump 1 according to the detection signal of
If the temperature of the deodorizing gas detected by the temperature detection sensor I4 is below a certain level, the rotation speed of the heat medium circulation pump 12 is lowered to heat the heat medium. The flow rate of the heat medium flowing in the fin tube 8 of the heat exchanger 7 is reduced, thereby reducing the thermal load on the deodorizing gas that heats the heat medium, and increasing the temperature of the deodorizing gas sent into the heat exchanger 3.

Further, if the temperature of the deodorizing gas detected by the temperature detection sensor 14 is above a certain level, the heat medium circulation pump 1
The temperature of the deodorizing gas fed into the heat exchanger 3 is increased by increasing the rotation speed of the heat exchanger 2 to increase the flow rate of the heat medium flowing in the fin tube 8 and increasing the thermal load of the deodorizing gas that heats the heat medium. control to reduce the

Further, in the embodiment, a pressure regulating valve 1 is provided between the heat medium circulation outward path ILa and the heat medium circulation return path 11b of the heat medium circulation system 11.
A bypass pipe line 18 with a heat medium heat recovery device 10 interposed therein is connected in parallel with the heat medium heat recovery device lO, and the pressure regulating valve 17 is controlled to open and close by a detection signal from a pressure detection sensor 9 that detects the pressure in the heat medium circulation outward path 11a. Specifically, when the pressure of the heat medium fed to the heat medium heat recovery device 10 through the heat medium circulation outward path 11a rises above a certain level, the pressure of the heat medium fed from the heat medium heater 7 is A part of the heat medium is directly supplied to the heat medium circulation return path 11b through a bypass pipe 18 at a stage before the heat medium heat recovery device 10.

Further, a pipe line 21 connected to an expansion tank 20 that absorbs the volumetric expansion of the heat medium circulating within the heat medium circulation system 11 is connected to the heat medium circulation return path 11b. When the heat medium is heated and expanded by the heat medium heater 7, a part of the heat medium is released into the expansion tank 20, or conversely, the volume of the heat medium circulating in the heat medium circulation system 11 is reduced. At the same time, the heating medium is automatically supplied from the expansion tank 20 to the heating medium circulation system 1 by the amount reduced.

In addition, in the figure, 22 is a storage tank for storing a heat medium, and a heat medium supply pump 23 is interposed to supply and fill the heat medium into the heat medium circulation system 11 when the heat medium heater 7 starts to start up. a thermal expansion absorption pipe 25 connected between the heating medium supply pipe 24 and the expansion tank 20 to absorb thermal expansion of the heating medium;
A heat medium level adjustment pipe 26 for adjusting the heat medium water level in the expansion tank 20 and a drain pipe 27 for draining and recovering the heat medium in the expansion tank 20 are connected to each other.

In addition, the hot air circulation system 9 of the drying device includes a burner 28 that heats the furnace air sucked from inside the drying furnace 1 and preheated by the heat medium heat recovery device 10 to a predetermined temperature; A hot air circulation fan 30 is installed which circulates and supplies the air through the filter 29 into the drying oven l.

Further, a temperature detection sensor 31 is installed in the drying oven 1 to detect the temperature inside the oven, and the temperature inside the oven is kept at a constant level lower than the optimum temperature for baking and drying the object to be coated (for example, about 170 to 180 degrees Celsius). A control motor 33 that adjusts the combustion amount of the burner 28 from temperature control devices 32a and 32b, respectively, based on a detection signal from a temperature detection sensor 31 that detects when the temperature becomes high or low; heat recovery device l
A control signal for controlling the operation of a solenoid valve 35 installed in a bypass pipe 34 that short-circuits and communicates the inlet side and the outlet side of O is outputted, and specifically, for example, When the temperature inside the furnace becomes higher than a certain level, the control motor 33 reduces the amount of fuel supplied to the burner 28 and the amount of combustion air supplied from the blower 36,
The electromagnetic valve 35 is opened to reduce the flow rate of the heat medium into the heat medium heat recovery device 10 or to control the flow to be stopped.

In addition, in the figure, 37 is a strainer, and 38 is an air vent valve.

The above is an example of the configuration of the exhaust heat recovery device (1) from the exhaust gas treatment device G (and the drying device using these) according to the present invention.Next, the operation thereof will be explained.

Prior to starting up the exhaust gas treatment device G, first open the air vent valve 38 of the expansion tank 20 and operate the heat medium supply pump 23 to transfer heat from the heat medium stored in the storage tank 22 through the heat medium supply pipe 23. feeding into the medium circulation system 11,
When the heating medium circulation system 11 is filled with the heating medium, the pump 23 is stopped to stop the supply of the heating medium, and at the same time, the air vent valve 38 is fully closed to prevent high-temperature oxidation of the heating medium. . In addition, as a heating medium, for example, about 300 to 330°C
Aromatic hydrocarbon heat transfer oil that can be used for ring formation up to a high temperature of 100℃ is used.
Each time it rises, its volume expands by about 10%.

In this state, the burner 28 installed in the hot air circulation system 9 of the drying oven 1 is combusted, and the combustion gas is transferred to the hot air circulation fan 3.
The atmosphere inside the drying oven 1 is maintained at a temperature of approximately 170 to 1, which is a temperature suitable for baking and drying the object to be coated.
The temperature is raised to about 80°C and the conveyance of the object to be coated is started.

At the same time, the exhaust gas in the drying oven 1 is sucked and discharged by the fan 2, and sent through the heat exchanger 3 of the exhaust gas treatment bag fiG to the catalyst bed 5 heated by the burner 4, and the exhaust gas of the exhaust heat recovery device H is The heat medium circulation pump 12 installed in the medium circulation return path 11b is operated to flow the heat medium into the fin tube 8 of the heat medium heater 7.

As a result, the exhaust gas at about 150 to 180°C, which is suctioned and discharged from the inside of the drying oven 1 by the fan 2, is passed through the catalyst layer 5, which is heated to about 350 to 450°C, which is a predetermined reaction temperature, by the burner 4. The heat of oxidation combustion when the harmful malodorous components in the exhaust gas are combusted and decomposed through the catalyst layer 5 is about 450 ~
A high temperature deodorized gas heated to 520°C is obtained.

The deodorizing gas heated to a high temperature in this way is sent into the heat medium heater 7, and heat is generated by heat exchange with the heat medium flowing in the fin tube 8 disposed in the heat medium heater 7. The temperature of the exhaust gas is lowered to a certain level or below, and then sent into the heat exchanger 3, and through heat exchange with the exhaust gas sent to the catalyst layer 5 through the heat exchanger 3, the exhaust gas is lowered to a temperature lower than the reaction temperature of the catalyst layer 5. For example, preheat to about 250 to 300°C.

In this way, in the exhaust gas treatment device G, the high-temperature deodorized gas that has been deodorized through the catalyst layer 5 loses heat through heat exchange with the heating medium flowing in the heating medium heater 7 of the exhaust heat recovery device II. The heat exchanger 3 is then fed into the heat exchanger 3 after its temperature is lowered below a certain level.

Therefore, the exhaust gas is transferred to the catalyst layer 5 without increasing the exhaust gas flow rate to lower the exhaust gas concentration, reducing the heat recovery efficiency of the heat exchanger 3, or turning off/off the combustion of the burner 4 as in the past. At the same time, it is possible to reliably prevent the temperature system of the entire device G from being preheated to a temperature higher than the reaction temperature of The exhaust heat from the exhaust gas treatment device G can be used effectively to the maximum without wasting it by sending the heat medium to the heat recovery device 10 and providing it as a heating source for preheating the air in the furnace.

That is, the heat medium passed through the fin tube 8 of the heat medium heater 7 and heated by heat exchange with the deodorizing gas is sent to the heat medium heat recovery device 10 through the heat medium circulation outward path 11a by the heat medium circulation pump 12. Since the air in the furnace that is fed and heated by the burner 27 of the hot air circulation system 9 is preheated, the amount of combustion in the burner 28 is reduced and fuel costs are saved.

At this time, when the temperature of the deodorizing gas sent into the heat exchanger 3 through the heat medium heater 7 falls below a certain level, which makes it impossible to sufficiently preheat the exhaust gas sent to the catalyst layer 5, the temperature detection sensor 1
In response to the detection signal from 4, the rotation speed of the heat medium circulation pump 12 driven by the inverter motor 15 is reduced.
The flow rate of the heat medium flowing through the fin tubes 8 of the heat medium heater 7 decreases, reducing the thermal load on the deodorizing gas that heats the heat medium, thereby increasing the temperature of the deodorizing gas sent into the heat exchanger 3. to maintain the preheating temperature of the exhaust gas constant.

Conversely, when the temperature of the deodorized gas detected by the temperature detection sensor 14 exceeds a certain level, the rotation speed of the heat medium circulation pump 12 is increased, and the fin tube 8 of the heat medium heater 7 is increased.
By increasing the flow rate of the heat medium flowing in the heat exchanger 3 and increasing the heat load of the deodorizing gas that heats the heat medium, the temperature of the deodorizing gas sent into the heat exchanger 3 is lowered, and the preheating temperature of the exhaust gas is abnormal. Prevent high temperatures.

As a result, the exhaust gas sent to the catalyst layer 5 through the heat exchanger 3 of the exhaust gas treatment device G is always preheated to a constant temperature, and at the same time, the heat dissipation temperature of the heat medium heat recovery device 1o is also maintained constant. It will be done.

In addition, when the pressure of the heat medium sent from the heat medium heater 7 to the heat medium heat recovery device 10 through the heat medium circulation outward path 11a becomes higher than a certain level, the heat medium heat recovery device 1o is maintained at 8 m. Therefore, the pressure regulating valve 1 is activated by the detection signal from the pressure detection sensor 19.
7 is opened and the heat medium circulation goes out! A part of the heating medium fed through the inside of la is directly flowed into the heating medium circulation return path 11b through the bypass pipe line 18.

Further, the heat medium flowing in the heat medium circulation system 11 is connected to the heat medium heater 7.
When the heat medium is heated and expanded within the fin tube 8, the volume expansion is released into the expansion tank 20 through the pipe line 2I, and the heat medium circulation system 11 is protected.

In addition, in the drying device K, when the temperature inside the drying oven 1 becomes higher than a predetermined baking temperature, a temperature detection sensor 31
The temperature control devices 32a and 32
From b to a control motor 33 that adjusts the combustion amount of the burner 28 and a solenoid valve 35 installed in the pipe line 34,
A control signal for reducing the combustion amount of the burner 28 and a control signal for increasing the amount of heat medium flowing through the pipe line 34 are output, respectively, so that the atmosphere in the drying oven I reaches a temperature suitable for baking and drying the object to be coated. will be maintained.

In the above embodiment, as the heat medium flow rate control means 13, the temperature of the deodorizing gas sent from the heat medium heater 7 into the heat exchanger 3 is detected by the temperature detection sensor 14, and the heat medium circulation is controlled based on the detection signal. Although the case where the rotational speed of the pump 12 is variably adjusted has been described, the heat medium flow rate control means according to the present invention is not limited to this, and may be, for example, as shown in FIG. 2.

That is, FIG. 2 is an explanatory diagram of the main parts of an exhaust heat recovery device showing another embodiment of the present invention, in which the heat medium flow rate control that variably adjusts the flow rate of the heat medium flowing in the heat medium heater 7 is shown. The means 13' includes a temperature detection sensor 40 that detects the temperature of the heat medium flowing in the heat medium circulation outward path 11a, and an inverter that variably controls the rotation speed of the heat medium circulation pump 12 according to a detection signal from the sensor 40. - It is composed of a motor 15.

In this case, when the temperature of the heat medium heated in the heat medium heater 7 due to heat exchange of the deodorized gas 7 of the exhaust gas treatment device G fluctuates due to the temperature change of the deodorized gas, the temperature detection sensor 40 detects the temperature change. By detecting this and variably adjusting the rotation speed of the heat medium circulation pump 12, the flow rate of the heat medium flowing through the fin tubes 8 of the heat medium heater 7 is variably adjusted, and the flow rate of the heat medium is sent into the heat exchanger 3. At the same time as the temperature of the deodorizing gas is maintained constant, the temperature of the heat medium fed to the heat medium heat recovery device 10 is also maintained constant.

Therefore, when the heat medium heat recovery device 10 is used, for example, as a radiant panel of a radiant drying furnace, the amount of radiant heat radiated from the radiant panel to the object to be coated is constant, so that the drying state of the object to be coated is optimal. It has the advantage that it is maintained at a high temperature without impairing the quality of the coating.

The heat medium heat recovery device 10 may be used as a heat source for preheating the furnace air that is interposed in the hot air circulation system 9 of the drying device and circulated into the drying furnace 1 as described above, or as a heating source as described above. It can be used not only as a radiant panel of a radiant drying furnace, but also as a heater for heating a pretreatment liquid in a painting pretreatment device, and other various heating sources.

〔Effect of the invention〕

As described above, according to the present invention, the high-temperature deodorized gas that has been deodorized through the catalyst layer of the exhaust gas treatment device passes through the heat medium heater of the exhaust heat recovery device and radiates heat by heat exchange with the heat medium. Afterwards, the exhaust gas is sent to a heat exchanger that preheats it, so the exhaust gas can be preheated without increasing the amount of exhaust gas sent from the exhaust gas source to the catalyst layer or stopping the combustion of the burner that heats the catalyst layer, as in the case of conventional methods. At the same time, it is possible to prevent abnormal upper limits of temperature, and at the same time, the heat medium heated by heat exchange with high-temperature deodorizing gas is circulated and supplied to the heat medium heat recovery device, which serves as a various heating source, and the exhaust heat from the exhaust gas treatment equipment is recovered. It has the excellent effect of being able to utilize it to the maximum extent possible.

In addition, the heat medium flow rate is supplied from the heat medium heater to the heat medium heat recovery device through the heat medium va ring path, and variably adjusts the flow rate of the heat medium flowing into the heat medium heater through the heat medium circulation return path. Since it is equipped with a control means, it is possible to maintain a constant temperature of the deodorizing gas sent from the heating medium heater to the heat exchanger that preheats the exhaust gas, and the heating medium is also fed from the heating medium heater. This has the effect that the heat radiation temperature of the heat medium heat recovery device can also be maintained constant.

[Brief explanation of drawings]

FIG. 1 is a flow sheet diagram showing an example of an exhaust heat recovery device from an exhaust gas treatment device according to the present invention, FIG. 2 is an explanatory diagram of main parts showing another embodiment of the present invention, and FIG. FIG. 1 is a schematic configuration diagram showing a processing device. Explanation of symbols G・-Exhaust gas treatment device, 1-Painting drying furnace (exhaust gas generation source), 2-Fan, 3-Heat exchanger, 4-Burner, 5-・
- catalyst layer, 6 - passage, H - exhaust heat recovery device, 7 - heat medium heater, 8 - fin tube, 1o - heat medium heat recovery device,
11-.-Heating medium circulation system, 11 a-Heating medium circulation outward path, 11
b.-Heat medium circulation return path, 12-.Heat medium circulation pump, 13.
13''--Heat medium flow rate control means, 14--One temperature detection sensor, 15--Inverter motor, 4o--Temperature detection sensor.

Claims (3)

[Claims] (1) Exhaust gas discharged from an exhaust gas generation source is preheated through a heat exchanger and sent to a catalyst layer heated to a predetermined reaction temperature by a burner, and the high-temperature deodorized gas is deodorized through the catalyst layer. An exhaust heat recovery device from an exhaust gas treatment device configured to be sent to a heat exchanger to preheat the exhaust gas and then discharged to the outside, the high-temperature deodorized gas being deodorized through the catalyst layer. a heat medium heater interposed in a passage for feeding the deodorizing gas to the heat exchanger; and a heat medium heated by heat exchange with the deodorizing gas in the heat medium heater and circulatingly supplying the heat medium to a heat medium heat recovery device. A heat medium circulation system comprising an outward heat medium circulation path and a return heat medium circulation path, and a heat medium flow rate control means for variably adjusting the flow rate of the heat medium flowing into the heat medium heater through the return heat medium circulation path. An exhaust heat recovery device from an exhaust gas treatment device, characterized in that: (2) The heat medium flow rate control means controls the heat medium flow rate in the heat medium heater in response to a detection signal from a temperature detection sensor that detects the temperature of the deodorizing gas sent from the heat medium heater to the heat exchanger. An exhaust heat recovery device from an exhaust gas treatment device according to claim 1, which is configured to variably control the rotation speed of a heat medium circulation pump that supplies a heat medium. (3) The heat medium flow rate control means supplies heat to the heat medium into the heat medium heater in response to a detection signal from a temperature detection sensor that detects the temperature of the heat medium flowing through the heat medium circulation outward path. An exhaust heat recovery device from an exhaust gas treatment device according to claim 1, which is configured to variably control the rotational speed of a medium circulation pump.