JP2734824B2 - Noxious gas heating purification equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heating and purifying apparatus for heating and oxidizing and purifying malodorous and harmful components such as carbon monoxide (CO) and hydrocarbons (HC) contained in exhaust gas from various types of combustion equipment.

[0002]

2. Description of the Related Art In recent years, it has become essential to purify and discharge CO and HC components generated during various types of combustion equipment and during drying and heat treatment due to their harmfulness and odor.
In addition, harmful gases are generated during the operation of the band machine or during fusion of resin, vinyl, and the like, and purification of the gases is required. CO
As a method for purifying the exhaust gas and HC components, a method in which the exhaust gas itself is heated and reacted with oxygen in the gas has the highest purification efficiency and high reliability. Generally, in order for oxygen in air to react with CO or HC, a temperature of 800 to 900 ° C. or higher is required. In the method using the oxidation catalyst, the reaction can proceed in a temperature range of 200 to 400 ° C., and the consumption of heat energy can be reduced.

A conventional harmful gas purifying apparatus will be described below with reference to the drawings. FIGS. 3A and 3B show the configuration of a conventional catalyst purifying device. FIG. 3A shows the configuration of a catalyst purification device main body, and FIG. 3B shows the configuration of a system including a heat exchanger. As shown in the figure, a heat exchanger 16, a heating device 12, and a catalyst 13 are provided in the catalyst purification device main body 10. The exhaust gas is introduced from the gas inlet 11 into the catalyst heating device main body 10, the temperature is raised to a predetermined temperature by the heating device 12, CO and HC are oxidized and purified by the catalyst 13, and the outlet 14
Is discharged from At this time, the energy required for raising the temperature of the exhaust gas is discharged together with the gas. FIG. 3B shows a system that uses a heat exchanger to recover a part of this energy. As shown in the figure, the exhaust gas introduced from the gas inlet 17 and heated in the heat exchanger 16 flows along the arrow and proceeds to the catalyst purification device main body 10. The purified gas enters the heat exchanger 16 again, is cooled, and is discharged from the gas outlet 18. With this heat exchanger, a part of the energy required for raising the temperature of the exhaust gas can be recovered and the energy loss can be reduced.

On the other hand, FIGS. 4A and 4B show an example of a heating and purifying apparatus using a heat accumulator, in which the state of FIG.
The heat energy is reduced by alternately repeating the state of (B). Heat exchange is performed by the heat storage unit 2 and the heating device 4. The flow of the harmful exhaust gas is controlled by the damper 9. In FIG. 4A, the exhaust gas is the gas inlet 1
From FIG. 9, proceed as indicated by an arrow 7 and enter the purifier main body 5 from the gas inlet / outlet 1. Further, the heat passes through the lower heat storage body 2 and is heated and purified by the heating device 4. The heat is taken away by the upper heat storage body 2, cooled, discharged from the gas inlet / outlet 8, and proceeds to the gas outlet 20. After a certain period of time, as shown in FIG. 4B, the dampers 9 are respectively operated so as to change the flow of the exhaust gas. That is, in FIG. 4 (A), the upper heat storage body 2 which has taken heat from the exhaust gas works to heat the exhaust gas,
Supplement some or most of the energy that heats the exhaust gas. By repeating the above steps, heat is trapped in the purification device, and energy is saved.

[0005]

However, the heat exchanger 16 used in the purifying apparatus shown in FIG. 3B is usually made of thin aluminum having good heat conductivity, and has a heat exchange efficiency of 50-60. % Is the limit. Further, aluminum cannot be used for exhaust gas containing corrosive gas such as SO _x and NO _x because aluminum corrodes. FIG. 4 (A),
By using a corrosion-resistant heat storage material in the purifier of FIG. 3B, the disadvantage of the purifier of FIG. 3B can be eliminated, and a purifier with high heat exchange efficiency can be realized. But,
When the concentrations of HC and CO components contained in the exhaust gas are high, heat generated by HC and CO generated during heating purification is accumulated in the heat storage material inside the purification device, and the heat storage material sometimes becomes abnormally high in temperature. Particularly, in a device using a catalyst, there is a problem that the performance of the catalyst is deteriorated and the purification ability is reduced.

An object of the present invention is to provide a heating and purifying apparatus which can be used safely even in the case of exhaust gas having a high concentration of harmful components and a large amount of heat generation.

[0007]

To achieve this object, a harmful gas heating and purifying apparatus according to the present invention comprises: a damper for alternately changing a flow direction of exhaust gas flowing in a purifying apparatus main body at regular intervals; A heating and purifying device comprising a heating device provided at the center of the purifier main body and a heat storage element provided in the middle of the exhaust gas flow path from both ends to the center, wherein the flow direction of the exhaust gas is reversed by switching the outlet and the inlet. As a control means for controlling the temperature, a temperature sensor is provided at a central portion of the main body of the purification device in addition to a time-dependent one, and the temperature is detected, and the flow direction of the exhaust gas is reversed according to the temperature.

[0008]

According to this structure, exhaust gas containing harmful components is introduced into the purifier from one end (entrance) for a certain period of time, and is purified by heating through the heat accumulator, cooled by the other heat accumulator layer and cooled by the other heat accumulator layer. (Exit). A damper provided at both ends of the purifier body is operated by a timer to reverse the flow of the exhaust gas. With this configuration, the heat storage material alternates between the functions of heat absorption and heat radiation, so that heat cannot escape from the purification device body.

Further, if high concentrations of HC and CO components are mixed in the exhaust gas, heat is generated at the time of heat purification, and the temperature inside the purification device becomes high until the heat balances with the heat loss. Here, when the temperature becomes higher than the specified temperature by the temperature control mechanism inside the purification device, if the flow direction of the exhaust gas is controlled so as not to be reversed, the exhaust gas continues to flow in one direction until the temperature becomes equal to or lower than the predetermined temperature, and the heat energy from the outlet portion is generated. There is no abnormal high temperature inside the purifier. When the temperature in the purification device is lower than the predetermined temperature, the flow direction of the exhaust gas is reversed, and it is possible to avoid applying extra heat by the heating device.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A harmful gas purifying apparatus according to one embodiment of the present invention will be described below with reference to the drawings.

(Embodiment 1) FIGS. 1A and 1B show a configuration of a heating and purifying apparatus according to an embodiment of the present invention. As shown in the figure, the exhaust gas exits through an inlet-side flow path 19 of the gas and enters through an outlet-side flow path 20 of the exhaust gas. The purifying device main body 5 includes the heat storage body 2 and the heating device 4, and is configured so that the flow direction of the exhaust gas in the purifying device is reversed by the damper 9.
The temperature sensor 21 controls the operation of the heating device, and the temperature sensor 22 controls overheating. Of course, the same two sensors may be used in common. FIG. 1 (A) and FIG.
(B) shows a state in which the flow of the exhaust gas inside the purification device is reversed. First, the state of FIG. The exhaust gas enters through the exhaust gas inlet 19, enters the purifier main body 5 from the exhaust gas inlet 1 as shown by the arrow 7, and enters the lower heat storage material 2.
And is heated and purified by the heating device 4. When passing through the upper heat storage material 2, the thermal energy of the exhaust gas is taken away, and the exhaust gas is cooled and discharged from the exhaust gas outlet 8 toward the exhaust gas outlet 20. Normally, after a certain time, the damper 9 is operated so that the exhaust gas flows from the top to the bottom in the purification device main body 5. This state is shown in FIG. However, if the exhaust gas contains a high concentration of HC or CO components, it is heated by the lower heat storage material 2 and reacts to increase the temperature. Since this heat is stored by the upper and lower heat storage materials, the temperature rises with each cycle. When the temperature sensor 22 detects an abnormally high temperature, the gas continues to flow in a certain direction without reversing the flow of the exhaust gas until the temperature decreases. There is a limit to heat storage in the heat storage material located on the leeward side, and heat is gradually released in the direction of the outlet, so that the cooling and purifying device is not put into a dangerous state.

Second Embodiment Next, a second embodiment of the present invention will be described with reference to the drawings.

The structure of the second embodiment is different from the first embodiment in that an oxidation catalyst 3 is arranged between the heat storage materials as shown in FIG. The function of this oxidation catalyst is to purify harmful gases at low temperatures. However, attention must be paid to the fact that as the temperature increases, the catalytic ability decreases. In this embodiment, a temperature sensor 22 for detecting an excessive temperature rise and controlling a damper is provided in the same manner as in the first embodiment. With this control means, a highly reliable harmful gas purifying device can be realized.

[0014]

As is apparent from the above description of the embodiment, according to the present invention, a damper for alternately changing the flow direction of the exhaust gas flowing in the purification device main body at regular intervals, and a damper at the center of the purification device main body. A heating and purifying device provided with a heating device and provided with a heat storage element in the middle of an exhaust gas flow path from both ends to the center. In addition to the timer control, the main body is used as a command control for switching an outlet and an inlet to reverse a flow direction of the exhaust gas. The temperature information provided by the temperature sensor provided at the center of the device is read, and when the temperature exceeds a predetermined temperature, heat is discharged together with the gas without reversing the flow direction of the exhaust gas. As a result, it is possible to prevent abnormal temperature rise that occurs at the time of heating and purification when high concentrations of HC and CO components are mixed in the exhaust gas, and to prevent deterioration and destruction of the purification device and damage to the catalyst and the heat storage material due to the high temperature. A harmful gas heating purification device can be provided.

[Brief description of the drawings]

FIG. 1A is a configuration diagram of a harmful gas heating / purifying apparatus according to a first embodiment of the present invention. FIG. 1B is a configuration diagram showing a state in which the flow of exhaust gas in FIG.

FIG. 2A is a configuration diagram of a harmful gas heating / purifying apparatus according to a second embodiment of the present invention. FIG. 2B is a configuration diagram showing a state in which the flow of exhaust gas in FIG.

FIG. 3A is a configuration diagram of a conventional catalyst purification device main body, and FIG. 3B is a configuration diagram of a conventional catalyst purification system including a heat exchanger.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Exhaust gas inlet 2 Heat storage material 3 Catalyst 4 Heater 5 Purifier main body 6 Exhaust gas flow path 7 Exhaust gas flow direction 8 Exhaust gas outlet 9 Damper 19 Exhaust gas inlet 20 Exhaust gas outlet 21 Heater sensor 22 Excessive rise Temperature sensing sensor

Continued on the front page (51) Int.Cl. ⁶ Identification code FI B01D 53/87

Claims (1)

(57) [Claims] 1. A damper for alternately changing the flow direction of exhaust gas flowing through a purification device main body at regular intervals, a heating device provided at the center of the purification device main body, and a heating device provided in the middle of the exhaust gas flow path from both ends to the center. Inside the body of the purification device
A heating and purifying apparatus having a temperature sensor provided in a central portion, wherein the control means switches a flow direction of exhaust gas at predetermined time intervals, and the flow direction of the exhaust gas is switched by temperature detection by the temperature sensor in the main body of the purification apparatus. A harmful gas heating and purifying apparatus including both control means.