JP2016211829A - System capable of concurrently performing harmless formation of exhaust gas generated at drying furnace or heating furnace, and heat recovery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a system capable of concurrently performing harmless formation of exhaust gas generated at drying furnace or heating furnace, and heat recovery.SOLUTION: A flow passage 2 for exhaust gas generated from a drying furnace or a heating furnace is provided with a primary heat exchanger 5 for recovering heat, its downstream side is provided with a catalyst combustion part 8, and further one stage or two-stage stacked secondary heat exchangers 10, 11 for recovering heat are connected to downstream side, fans 13, 15 are installed at each of heat exhaust side and heat receiving side so as to cause normal temperature surrounding air of the same amount as that of the exhaust gas in the furnace to be recovered for its heat under a high efficiency. Heat received surrounding air is fed into the secondary heat exchanger and the surrounding air of which temperature is increased by the secondary heat exchanger is discharged into a heated chamber. The catalyst is platinum catalyst and the exhaust gas is fed into a burner combustion chamber 4 to increase its temperature, so that it is not necessary to prepare additional heating device for catalyst combustion and so the catalyst combustion can be carried out under a heat exchanging cycle.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a system capable of simultaneously detoxifying exhaust gas generated in a drying furnace or heating furnace and recovering heat, and in particular, by providing a catalyst in the middle of a heating system of the drying furnace or heating furnace, The present invention relates to a system capable of recovering exhaust gas that has been released into the atmosphere without being recovered and simultaneously detoxifying it.

  In the system capable of simultaneously detoxifying exhaust gas generated in the drying furnace or heating furnace and recovering heat in the present invention, a heat exchanger for heat recovery is provided in two stages in the exhaust gas flow path, and a catalyst is provided between them. By providing a combustion section, the exhaust gas is rendered harmless, and heat recovery is performed with high efficiency.

  In addition, the secondary heat exchanger has a one-stage or two-stage structure. In the case of two-stage structure, the No. of the upper stage of the secondary heat exchanger is connected via an intake fan installed at the heat receiving side inlet of the secondary heat exchanger. No. 2 secondary heat exchanger at normal temperature outside air was introduced, the lower No. 2 1 The heat receiving air of the outside air flows into the secondary heat exchanger, and the air heated by the secondary heat exchanger is discharged into the furnace, and the catalyst in the exhaust gas combustion process is a platinum catalyst The decomposition of exhaust gas is to simultaneously perform detoxification and heat recovery of exhaust gas generated in a drying furnace or heating furnace characterized in that the combustion temperature in the platinum catalyst is around 400 ° C. where the activity is high. It is a system that can.

JP 2010-281525 A "Exhaust gas heat recovery system" Japanese Unexamined Patent Publication No. 3-217273 "Drying furnace exhaust gas treatment device"

  Conventionally, there has been a need for a system capable of simultaneously detoxifying exhaust gas generated in a drying furnace or heating furnace and recovering heat from exhaust gas at a relatively low temperature level, which has been difficult to recover heat.

  According to the system capable of simultaneously detoxifying exhaust gas generated in the drying furnace or heating furnace and recovering heat in the present invention, the exhaust gas flow path is provided with a primary heat exchanger for heat recovery, and a catalyst is provided downstream of the heat exchanger. A combustion section is provided, and a secondary heat exchanger for heat recovery is connected to the downstream, and fans are installed on each of the exhaust heat side and the heat reception side. It is characterized in that heat recovery is performed with high efficiency, the temperature is raised and released into the furnace, and the catalyst in the catalytic combustion process is a platinum catalyst, and the decomposition of the exhaust gas is the combustion temperature at the platinum catalyst. It is possible to provide a system capable of simultaneously detoxifying exhaust gas and recovering heat, characterized by having a high activity around 400 ° C.

  Further, the exhaust gas having a high temperature in the furnace can be released to the atmosphere at a reduced temperature by a heat exchange system.

  Further, exhaust gas containing harmful substances can be rendered harmless by catalytic combustion using a platinum catalyst.

  Further, the outside air can be taken into the furnace at a temperature higher than the outside air temperature by the heat exchange system.

  According to the system capable of simultaneously detoxifying exhaust gas generated in a drying furnace or heating furnace and recovering heat, the energy of exhaust gas is recovered and reused despite the indirect heating method. Cost (fuel consumption) can be greatly reduced.

In addition, there is no need for a device for heating the exhaust gas for the catalytic reaction, and by controlling the heat generated in the normal system process, an appropriate temperature for the catalytic reaction can be obtained. A detoxification system can be provided.

  Further, by adopting a secondary heat exchanger made of aluminum having a heat resistance up to 420 ° C. and making the secondary heat exchanger in two stages, the thermal efficiency can be further increased.

  In order to perform heat exchange of exhaust gas in a two-stage heat exchanger, exhaust gas is released to the atmosphere at a temperature lower than the exhaust gas temperature in the drying furnace or heating furnace, and the intake air is a single-stage or two-stage secondary heat. In order to exchange the heat of the outside air with an exchanger, it was possible to introduce it at a temperature higher than the outside air temperature.

  In addition, since all the equipment except the heat exchange fan and the heating burner are housed in the drying furnace or heating furnace, each equipment does not need to be kept warm, and no warming measures are taken. Heat is dissipated from the entire exhaust gas flow path, there is little heat energy loss, and maintenance and desorption of each device is easy.

  Below, the feature of the catalyst which employ | adopted the platinum catalyst of a honeycomb shape or a granular form as a catalyst and uses the raw material which increased platinum content rather than the normal platinum catalyst is demonstrated.

  Since platinum has the ability to catalytically burn various gas components at low temperatures, it is suitable for exhaust gas purification applications that contain multiple gases. Platinum catalysts are also particularly effective against VOCs (odorous substances). Are better.

  The catalyst used in the present invention is a honeycomb-shaped platinum catalyst, has a low pressure loss, is excellent in heat resistance and durability, and is said to be inferior in activity compared to granular, but the platinum content is about the normal about Because it uses twice as much platinum, high activity is achieved.

  Compared to the direct combustion method in which exhaust gas is burned directly at high temperature to make it harmless, the catalytic combustion method that completely oxidizes (deodorizes) at low temperature by passing the catalyst significantly reduces the energy cost (fuel consumption). In addition, the system of the present invention does not require any particular fuel for the catalyst because it uses the heat generated in the normal system process.

  Since the catalytic combustion method has a lower combustion temperature than the direct combustion method, it generates less NOx (nitrogen oxides) and is an environmentally friendly method.

  In the present invention, the exhaust gas usually reacts with air by controlling the heat generated in the process of the system at 380 to 420 ° C. and brought into contact with the platinum catalyst, and changes into carbon dioxide gas and water.

  Catalytic combustion using a catalyst is the most economical combustion method, but the activity is not performed permanently, and deterioration proceeds with catalyst poison.

Chloride compounds and sulfur compounds are oxidatively decomposed on the contact surface, and the catalytic reaction temperature at that time needs to be 350 ° C. or higher. Below the reaction temperature, they adsorb on the catalyst surface and cause deterioration.
If the exhaust gas contains silicone or organophosphorus compound, the catalyst surface is coated to reduce the activity, and if the processing gas contains dust (mostly metal oxide), it is poisoned and the catalyst to degrade.

  At an exhaust gas temperature of 360 to 420 ° C., it is difficult to be affected by catalyst poison.

  1 is a flow sheet of a configuration example of a system capable of simultaneously detoxifying exhaust gas generated in a drying furnace and a heating furnace and recovering heat according to the present invention.

  DESCRIPTION OF EMBODIMENTS Hereinafter, modes for carrying out the present invention will be specifically described based on embodiments shown in the drawings. Below, a heat recovery system is demonstrated along the flow of exhaust gas, and the flow of heat receiving air.

First, the flow of exhaust heat gas will be described.
Exhaust gas generated in the drying furnace or heating furnace is sucked from the exhaust gas suction port 1 and sent to the burner combustion chamber 4 via the exhaust gas suction duct.

  The air heated in the burner combustion chamber 4 is branched in the burner combustion chamber 4, is subjected to heat exchange in the primary heat exchanger 5, enters the collecting chamber 6 after the primary heat exchange, and the exhaust gas of the primary heat exchanger 5 is again supplied. Join.

  This process reduces the temperature from 380 ° C to 420 ° C.

  The assembly chamber 6 after the primary heat exchange enters the catalyst combustion section 8 via the assembly chamber-catalyst combustion section connection duct 7 after the primary heat exchange. At this time, the temperature of the catalyst is 380 ° C to 420 ° C.

  The gas that has passed through the catalyst combustion section 8 is the catalyst combustion section No. No. 1 through the secondary heat exchanger (exhaust heat side inlet) connection duct 9 1 Enters the secondary heat exchanger 10.

  If the secondary heat exchanger is a two-stage stack with high efficiency, the No. The exhaust heat side inlet temperature of the 1st secondary heat exchanger 10 will be 370 degreeC-410 degreeC.

  No. The exhaust gas heat-exchanged in the secondary heat exchanger 10 is No. 1 from the exhaust heat side outlet. 2 Enter the secondary heat exchanger 11.

  No. No. 1 secondary heat exchanger 10 has an exhaust heat side outlet temperature of 250 ° C. to 270 ° C. It becomes the same temperature as the exhaust heat side inlet of the 2nd secondary heat exchanger 11.

  The heat radiation side outlet temperature of the No. 2 secondary heat exchanger 11 decreases to 120 ° C. The secondary heat exchanger (exhaust heat side outlet) to the exhaust heat side fan connection duct 12 passes through the atmospheric discharge duct 14 from the exhaust heat side fan 13 and is released into the atmosphere.

Hereinafter, the flow of the heat receiving air will be described.
As the heat receiving air, outside air is taken in from the heat receiving side fan 15, and the heat receiving side fan No. No. 2 through the secondary heat exchanger (heat receiving side inlet) connection duct 16. 2 is connected to the heat receiving side inlet of the secondary heat exchanger 11. The outside air intake temperature of the heat receiving side fan 15 is normal temperature.

  No. The air heated to about 150 ° C. at the heat receiving side outlet of the secondary heat exchanger 11 is No. 2. 2 Secondary heat exchanger (heat receiving side outlet) to No. 2 No. 1 secondary heat exchanger (heat receiving side inlet) connecting duct 17, no. 1 is connected to the secondary heat exchanger 10, heated to about 250 ° C. to 270 ° C. at the heat receiving side outlet, and discharged into the drying furnace or heating furnace 20.

The reason why the platinum catalyst is selected for catalytic combustion will be described below.
Because platinum has the ability to catalytically burn various gas components at low temperatures, it is suitable for exhaust gas purification applications that contain multiple gases. Platinum catalysts are also excellent against VOCs (odorous substances) ing.

The platinum catalyst used in the present invention is a honeycomb or granular platinum catalyst.
In particular, honeycomb-shaped catalysts have less pressure loss, are superior in heat resistance and durability, and are said to be less active than granular shapes, but use platinum that is twice the normal platinum content. Therefore, high activity is realized.

  Compared to the direct combustion method in which exhaust gas is burned directly at high temperature to make it harmless, the catalytic combustion method that completely oxidizes (deodorizes) at low temperature by passing the catalyst significantly reduces the energy cost (fuel consumption). In addition, the system of the present invention does not require any particular fuel for the catalyst because it uses the heat generated in the normal system process.

  Since the catalytic combustion method has a lower combustion temperature than the direct combustion method, it generates less NOx (nitrogen oxides) and is an environmentally friendly method.

  In the present invention, the exhaust gas usually reacts with air by controlling the heat generated in the process of the system at 380 to 420 ° C. and brought into contact with the platinum catalyst, and changes into carbon dioxide gas and water.

  Catalytic combustion using a catalyst is the most economical combustion method, but its activity deteriorates temporarily or permanently.

Chloride compounds and sulfur compounds are oxidatively decomposed on the contact surface, and the catalytic reaction temperature at that time needs to be 350 ° C. or higher. Below the reaction temperature, they adsorb on the catalyst surface and cause deterioration.
If the exhaust gas contains silicone or organophosphorus compound, the catalyst surface is coated to reduce the activity, and if the processing gas contains dust (mostly metal oxide), it is poisoned and the catalyst to degrade.

  At an exhaust gas temperature of 360 to 420 ° C., it is difficult to be affected by catalyst poison.

Since the system capable of simultaneously detoxifying and recovering heat from the exhaust gas generated in the drying furnace or heating furnace of the present invention is configured as described above, the exhaust gas is directly burned at a high temperature to make it harmless. Compared to the direct combustion method, the catalytic combustion method that completely oxidizes (deodorizes) at a low temperature by passing the catalyst can significantly reduce the energy cost (fuel consumption). By using the heat generated in the process, no fuel is required for the catalyst.
In addition, the catalytic combustion method has a lower combustion temperature than the direct combustion method, and thus generates less NOx (nitrogen oxide), is an environmentally friendly method, and has high industrial utility value.

1. 1. Furnace exhaust gas inlet 2. Exhaust gas suction duct Heating burner 4. 4. Burner combustion chamber Primary heat exchanger 6. 6. Assembly chamber after temporary heat exchange 7. Assembly chamber to catalyst combustion chamber after temporary heat exchange Connection duct Catalytic combustion section 9. Catalyst combustion section to No. 1 Secondary heat exchanger (exhaust heat side inlet) connection duct No. 1 Secondary heat exchanger No. 2 Secondary heat exchanger 12. No. 2 Secondary heat exchanger (exhaust heat side outlet) to exhaust heat side fan connection duct 13. Exhaust heat side fan 14. Atmospheric discharge duct 15. Heat receiving side fan 16. Heat receiving side fan No. 2 Secondary heat exchanger (heat receiving side inlet) connection duct 17. No. 2 Secondary heat exchanger (heat receiving side outlet) to No. 2 1 Secondary heat exchanger (heat receiving side inlet) connection duct 18. Heat receiving side air outlet 20. Drying furnace or heating furnace

Claims (4)

  A primary heat exchanger for heat recovery is provided in an exhaust gas flow path generated in a drying furnace or a heating furnace, a catalyst combustion section is provided downstream thereof, and a one-stage or two-stage stacked secondary heat exchanger for heat recovery is further provided downstream thereof. And a fan installed on each of the exhaust heat side and the heat reception side, so that the outside air at the same temperature as the amount of exhaust gas in the furnace can be recovered with high efficiency. A system capable of simultaneously detoxifying exhaust gas generated in a furnace or heating furnace and recovering heat.   2. The heat receiving air of the outside air is introduced into the secondary heat exchanger, and the outside air heated by the secondary heat exchanger is discharged into the drying furnace or the heating furnace. A system that can simultaneously detoxify exhaust gas generated in a drying furnace or heating furnace and recover heat.   The catalyst in the catalytic combustion process is a platinum catalyst, and the temperature is raised by introducing exhaust gas into the burner combustion chamber, so there is no need for a separate heating device for catalytic combustion, and catalytic combustion is possible in the heat exchange cycle. The system capable of simultaneously detoxifying exhaust gas generated in a drying furnace or a heating furnace and recovering heat in the drying furnace according to claim 1.   The decomposition of the exhaust gas is carried out by making the combustion temperature of the platinum catalyst around 400 ° C. with high activation efficiency, simultaneously detoxifying exhaust gas generated in the drying furnace or heating furnace and recovering heat. A system that can be done.

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