JP3028897B2 - Exhaust gas treatment equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust gas treatment apparatus for treating high-temperature (850 DEG C. to 950 DEG C.) flue gas discharged from a combustion furnace such as an incinerator or the like. The present invention relates to a technique for controlling cooling water to be injected to perform cooling.

[0002]

2. Description of the Related Art Conventionally, as this type of exhaust gas treatment apparatus,
For example, a configuration as shown in FIG. 2 is employed.

In FIG. 1, reference numeral 1 denotes a gas cooling chamber into which combustion exhaust gas from an incinerator (not shown) is fed, and 2a and 2b.
Is a spray nozzle which is disposed in the gas cooling chamber 1 in two upper and lower stages and injects cooling water to exhaust gas in the gas cooling chamber 1 and includes a cooling water supply pipe 3 and a return pipe 4. I have.
The cooling water supply pipe 3 and the return pipe 4 are branched and connected to the spray nozzles 2a and 2b, respectively. Reference numeral 5 denotes a return valve provided in the return pipe 4, and the amount of return water is controlled by adjusting the degree of opening thereof.
The amount of cooling water injected from a and 2b is controlled. 6 is an air preheater for exchanging heat between the exhaust gas discharged from the gas cooling chamber 1 and air, 7 is a dust collector to which the exhaust gas from the air preheater 6 is fed and removes dust in the exhaust gas.
Reference numeral 8 denotes a temperature sensor for detecting the temperature of the exhaust gas near the inlet of the dust collector 7. When the temperature detected by the sensor 8 is high, the return valve 5 is operated to the open side. The temperature sensor 8 is operated so that the valve 5 is operated to the closed side.
And the return valve 5 are electrically connected.

[0004]

According to the conventional exhaust gas treatment apparatus configured as described above, the opening degree of the return valve 5 is adjusted by detecting the exhaust gas temperature downstream of the air preheater 6. Since the amount of cooling water injected from each of the spray nozzles 2a and 2b is controlled, the response of the control of the amount of cooling water by the return valve 5 is poor, and the spray nozzles 2a and 2b
b) The amount of spray water from b may increase more than necessary, so that the fluctuation of the pressure control in the incinerator becomes large and the cooling water is directly applied to the refractory material inside the gas cooling chamber 1 to deteriorate the refractory material. There was a problem such as letting.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and always maintains the temperature of the exhaust gas from the gas cooling chamber appropriately to suppress fluctuations in the furnace pressure control and to prevent air preheating. It is an object of the present invention to provide an exhaust gas treatment apparatus capable of improving the heat exchange efficiency in a gas cooler, suppressing generation of surplus water in a gas cooling chamber, and preventing deterioration of a refractory material.

[0006]

In order to achieve the above object, an exhaust gas treatment apparatus according to the present invention comprises a gas cooling chamber into which combustion exhaust gas from a combustion furnace is fed, and a gas cooling chamber provided in the gas cooling chamber. A plurality of spray nozzles for injecting cooling water into upper and lower stages to exhaust gas in the cooling chamber; an air preheater for exchanging heat with the exhaust gas discharged from the gas cooling chamber; and dust in the exhaust gas from the air preheater. In the exhaust gas treatment device provided with a dust collector for removing water, the return water amount is adjusted by adjusting the opening degree to each of the return pipes from the plurality of spray nozzles.
To control the amount of cooling water injected from the spray nozzle
The return valve is provided, the return valve of which is provided in the upper part of the spray nozzle of the return pipe, the open side when it hot by detecting the exhaust gas temperature in the vicinity of the inlet of the dust collector, and when the low temperature close side And a return valve provided in the return pipe of the lower spray nozzle detects the temperature of the exhaust gas near the outlet of the gas cooling chamber, opens it when it is hot, and opens it at low temperature. It is configured to be controlled to the closed side at the time.

[0007]

According to the present invention, the temperature of exhaust gas near the outlet of the gas cooling chamber is detected to control the amount of cooling water injected from the lower spray nozzle in the gas cooling chamber. That is, the exhaust gas cooling in the gas cooling chamber is directly controlled, and the temperature of the exhaust gas near the inlet of the dust collector is detected to control the amount of cooling water injected from the upper spray nozzle in the gas cooling chamber. As a result, the wave of temperature change when the exhaust gas cooling in the gas cooling chamber is directly controlled is reduced, the temperature of the exhaust gas sent out from the gas cooling chamber is always maintained properly, and the heat exchange in the air preheater is performed. It is possible to suppress the generation of surplus water while maintaining sufficient efficiency.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram of an exhaust gas treatment apparatus according to one embodiment of the present invention.

In FIG. 1, reference numeral 1 denotes a gas cooling chamber into which exhaust gas discharged from a combustion furnace (not shown) is fed.
Numeral 2b is a spray nozzle which is disposed in the gas cooling chamber 1 in upper and lower stages and injects cooling water to exhaust gas in the gas cooling chamber 1, and 3 supplies cooling water to the respective spray nozzles 2a and 2b. The supply pipe 3 is branched and connected to each of the spray nozzles 2a and 2b. Reference numerals 4a, 4b denote return pipes from the spray nozzles 2a, 2b, 5a, 5
b is a return valve provided in each return pipe 4a, 4b,
The amount of return water is controlled by adjusting the opening degree, whereby the amount of cooling water injected from the spray nozzles 2a and 2b is controlled. Reference numeral 6 denotes an air preheater for exchanging heat between the exhaust gas from the gas cooling chamber 1 and the air, and reference numeral 7 denotes a dust collector to which the exhaust gas passing through the air preheater 6 is fed to remove dust in the exhaust gas.

Reference numeral 8 denotes a temperature sensor for detecting the temperature of the exhaust gas near the inlet of the dust collector 7. When the temperature detected by the sensor 8 is high, one return valve 5a is operated to the open side, and the temperature is detected. Is lower, the temperature sensor 8 and the return valve 5a are electrically connected so that the return valve 5a is operated to the closed side. Reference numeral 9 denotes a temperature sensor for detecting the exhaust gas temperature near the outlet of the gas cooling chamber 1. When the temperature detected by the sensor 9 is high, the other return valve 5b is operated to the open side, and when the detected temperature is low. Has a return valve 5b
Temperature sensor 9 and return valve 5 so that
b is electrically connected.

Next, the operation of the above configuration will be described. When the combustion exhaust gas from the incinerator is sent to the gas cooling chamber 1, cooling water is injected from the upper and lower two-stage spray nozzles 2 a and 2 b to the exhaust gas in the gas cooling chamber 1. At this time, the temperature of the exhaust gas from the incinerator is usually 85
0 to 950 ° C., and it is desirable that the temperature of the exhaust gas when it is cooled and sent out in the gas cooling chamber 1 is controlled to about 450 ° C. Therefore, the temperature sensor 9 is connected to the outlet of the gas cooling chamber 1. The temperature of the exhaust gas in the vicinity is detected, and the lower spray nozzle 2 in the gas cooling chamber 1 is detected in accordance with the temperature of the exhaust gas.
By controlling the amount of cooling water injected from b, the exhaust gas is directly cooled in the gas cooling chamber 1.

On the other hand, the temperature sensor 8 detects the temperature of the exhaust gas in the vicinity of the inlet of the dust collector 7 and controls the amount of cooling water injected from the upper spray nozzle 2a in the gas cooling chamber 1. While reducing the wave of the temperature change accompanying the direct cooling of the exhaust gas in 1, keeping the temperature of the exhaust gas sent out from the gas cooling chamber 1 always appropriate, and properly performing the air preheating by the air preheater 6, The generation of surplus water in the cooling chamber 1 can be suppressed as much as possible.

[0013]

As described above, according to the present invention, the amount of cooling water from the upper spray nozzle is controlled based on the detection of the temperature of exhaust gas near the inlet of the dust collector, and the outlet of the gas cooling chamber is controlled. By controlling the amount of cooling water from the lower spray nozzle based on the detection of the exhaust gas temperature near the section, the wave of the temperature change of the exhaust gas accompanying the direct exhaust gas cooling in the gas cooling chamber is reduced, By maintaining the temperature of the exhaust gas sent from the gas cooling chamber at a temperature appropriate for air preheating, fluctuations in pressure control inside the incinerator can be kept low, and heat exchange efficiency in the air preheater can be improved. Although it is possible, there is an effect that generation of surplus water in the gas cooling chamber can be suppressed and deterioration of the refractory material can be prevented.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing an exhaust gas treatment apparatus according to one embodiment of the present invention.

FIG. 2 is a schematic configuration diagram showing a conventional exhaust gas treatment device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Gas cooling chamber 2a, 2b Spray nozzle 3 Supply piping 4a, 4b Return piping 5a, 5b Return valve 6 Air preheater 7 Dust collector 8, 9 Temperature sensor

──────────────────────────────────────────────────続 き Continuation of the front page (56) References Japanese Utility Model Showa 52-16777 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) F23J 15/04 ZAB

Claims (1)

(57) [Claims] 1. A gas cooling chamber into which combustion exhaust gas from a combustion furnace is fed, a plurality of spray nozzles disposed in the gas cooling chamber, and configured to inject cooling water to the exhaust gas in the cooling chamber in upper and lower stages. An air preheater that is heat-exchanged with the exhaust gas discharged from the gas cooling chamber, and an exhaust gas treatment device including a dust collector that removes dust in the exhaust gas from the air preheater, wherein the plurality of spray nozzles it's the return pipe
In each case, the amount of return water is controlled by adjusting the opening and the spray nozzle
Controlling the amount of cooling water injected from the return valve is provided, of which a return valve provided on the upper spray nozzle return pipe, the dust collector open side when detecting the exhaust gas temperature near the inlet port it hot And a control valve is provided on the return pipe of the lower spray nozzle to detect the temperature of the exhaust gas near the outlet of the gas cooling chamber and detect that the temperature is high. An exhaust gas treatment device characterized in that the exhaust gas treatment device is configured to be controlled to open when the temperature is low and to close when the temperature is low.