JPS605269Y2 - Fully evaporative gas cooling tower - Google Patents

Description

[Detailed description of the invention] This invention is installed upstream of an exhaust gas treatment system, especially an electrostatic precipitator, to cool high-temperature exhaust gas by direct contact with water and to avoid creating a slurry of dust to be removed. This relates to a so-called complete water evaporation type gas cooling tower.

In conventional gas cooling towers of this type, when the water supply to the water injection nozzle is stopped, the residual water in the water supply pipe drips from the nozzle mouth and reaches the bottom of the tower without evaporating, eliminating the advantage of complete evaporation and causing dust. may interfere with the discharge of

This invention sends high-pressure purge air to the water injection nozzle when the water supply is stopped, blowing the remaining water in the water supply pipe into the tower as fine particles and evaporating it at a rapid rate, and also prevents dust from entering the nozzle. The object of the present invention is to provide a completely evaporative gas cooling tower in which nozzle clogging does not occur.

Therefore, the configuration of the present invention is such that the water injection nozzle has a double structure consisting of a water supply passage and a return water passage, and the water supply pipe connected to the water supply passage has an on-off valve and an on-off valve. and an air pipe that sends purge air to the water injection nozzle during operation, and the return wood pipe connected to the return water passage is provided with a flow rate control valve that adjusts the amount of return water discharged, and furthermore, a flow rate control valve provided at the gas outlet is provided. It is characterized by comprising a gas temperature detector and a valve controller that controls the multiple valves based on a temperature signal from the detector.

An embodiment of the present invention will be described below with reference to the drawings.

In Fig. 1, a is a gas cooling tower, which has a gas port 1 that introduces high-temperature exhaust gas from an incinerator or the like (not shown), a gas outlet 2 that discharges cooled gas, and a number of water jets that will be described later. It has a nozzle 3 and a gas temperature detector 4 provided at the outlet 2.

As shown in FIG. 4, the water injection nozzle 3 has a double structure consisting of an inner passage through which water passes, the outer passage being a water supply passage 5, and the inner passage being a return water passage 6. .

That is, a larger amount of water 10 than the amount of water injected from the nozzle port 8 as shown by the arrow 9 via the rotary vane 7 is flowed into the water supply passage 5, and the excess water is returned from the return waterway 6 as shown by the arrow 11. , the injection pressure is always kept at a predetermined value.

Next, as shown in FIG.
A water supply pipe 14 is connected to the water supply passage 5 via a flexible hose 12, a return water pipe 15 is connected to the return water passage 6 via a flexible hose 13, and a compressed air pipe 16 is also connected to the water supply passage 5. ing.

To explain this with reference to FIG. 3, the water supply pipe 14 connected to the water supply passage 5 includes an on-off valve 17 and a compressed air pipe 16 that supplies purge air to the water supply passage 5 when the on-off valve 17 is closed. , a return water pipe 1 connected to a return water passage 6
5 is equipped with a flow rate control valve 18 for adjusting the discharge amount of return water.

It also includes a valve controller 20 that operates multiple valves based on a signal from a gas temperature detector 4 provided at the gas outlet 2, and a reference signal transmitter 21.

That is, the valve controller 20 compares the signal from the gas temperature detector 4 and the signal from the reference signal transmitter 21, and if the gas temperature is lower than a predetermined temperature, the valve controller 20 closes the flow rate control valve 18.
Increase the opening degree, and in the opposite case, decrease it.

Further, the valve controller 20 opens the air valve 19 provided in the air pipe 16 when the on-off valve 17 of the water supply pipe 14 is closed.

Completely evaporative gas cooling tower a configured as shown in Figure 1
, high temperatures generated in incinerators (e.g. 90
00C exhaust gas flows in from the gas population 1 and is cooled by direct contact with water jetted from a large number of water injection nozzles 3. At this time, the water is completely evaporated, and the cooling gas (e.g. 300°C ) and collected using an electrostatic precipitator (not shown).

On the other hand, the dust removed during gas-liquid contact falls to the bottom of the tower in powder form and is discharged outside the tower by a cutting machine.

Valve operations during operation of cooling tower a will be explained with reference to FIG. 3. The on-off valve 17 is fully open, and the entire amount of cooling water passes through the water supply passage 5 from the water supply pipe 14, and only the necessary fixed amount is is injected from the water injection nozzle 3 as indicated by arrow 9 to cool the aforementioned exhaust gas.

Excess cooling water that is not injected from the nozzle 3 is returned from the return waterway 6 through the return water pipe 15 and the flow rate control valve 18.

Here, even if the amount or temperature of the exhaust gas flowing into the cooling tower a changes, if the amount of cooling water injected from the water injection nozzle 3 remains unchanged, the gas discharged from the gas outlet 2 will change. The temperature may not reach a low temperature, which may cause problems with subsequent electrostatic precipitators, or conversely, the injected water may not evaporate completely, creating slurry.

Therefore, in order to avoid the above problems, the gas temperature at the gas outlet 2 is detected by the gas temperature detector 4, and if the temperature is lower than a predetermined value, the valve controller 20 controls the opening of the flow rate control valve 18. Increase the temperature and increase the amount of return water to the nozzle 3.
Reduce the amount of cooling water injected from the

Conversely, if the temperature is higher than a predetermined value, the valve controller 20 reduces the opening degree of the flow rate control valve 18 and increases the amount of cooling water injected from the nozzle 3.

That is, the valve controller 20 compares the signal from the gas temperature detector 4 and the signal from the reference signal transmitter 21, and controls the flow rate control valve 18 according to the deviation so that the deviation is reduced. do.

In this way, even if there is a fluctuation in the high-temperature exhaust gas flowing in from the gas population 1, the valves are operated so that no trouble occurs.

When there is no need to supply water to the water injection nozzle 3, the on-off valve 17 is fully opened, but in this case, the valve controller 2
At the same time as the on-off valve 17 is fully opened, the air valve 19 is fully opened for a certain period of time, and compressed air is sent to the water injection nozzle 3 as purge air, and the cooling water remaining in the nozzle 3 is turned into fine particles inside the cooling tower a. This prevents the dust from dripping and also prevents the dust from entering the nozzle opening.

As described above, the present invention has a water injection nozzle having a double structure consisting of a water supply passage, a water supply pipe connected to the water supply passage having an on-off valve, and a return water pipe connected to the return water passage. The woodwind is equipped with a flow rate control valve that adjusts the amount of return water discharged, so by adjusting this flow rate control valve,
The amount of water sprayed can be adjusted while maintaining the water pressure of the water spray nozzle at a predetermined value.

Moreover, it includes a gas temperature detector provided at the gas outlet and a valve controller operated by a signal from this detector, and the flow rate regulating valve is adjusted by the valve controller.
Even if there are fluctuations in the exhaust gas flowing in from the gas inlet, the amount of cooling water injected from the water injection nozzle is properly controlled, and the injected water is completely evaporated, no slurry is generated, and the system is cooled. The gas that is supposed to be at a high temperature will not cause problems with subsequent electrostatic precipitators.

Moreover, since the valve controller opens the air valve of the air pipe and supplies high-pressure purge air to the water injection nozzle when the on-off valve of the water supply pipe is closed, the cooling water remaining in the nozzle is converted into fine particles. Purging prevents the dust from dripping and also prevents dust from entering the nozzle port, thereby avoiding clogging of the nozzle port.

[Brief explanation of drawings]

Fig. 1 is a sectional elevational view showing one embodiment of the present invention, Fig. 2 is an enlarged view of part A in Fig. 1, Fig. 3 is an explanatory diagram of the piping of the water injection nozzle in Fig. 1, FIG. 4 is an enlarged partially cutaway sectional view of the same nozzle. a... Gas cooling tower, 1... Gas inlet,
2...Gas outlet, 3...Water injection nozzle, 4...Gas temperature detector, 5...Water supply passage, 6... Return water passage, 14... Water supply pipe, 15... Return water pipe, 16... Compressed air pipe, 17... Open/close valve, 18...・・・
Flow rate control valve, 19...Air valve, 20...
- Valve controller, 21...Reference signal transmitter.

Claims (1)

[Scope of utility model registration request] In a gas cooling tower that has a water injection nozzle that cools high-temperature exhaust gas by direct contact with water, and evaporates the injected water and discharges the dust to be removed in powder form, the water injection nozzle is , has a double structure having a water supply passage and a return water passage for returning excess water, and the water supply pipe connected to the water supply passage has an on-off valve, and when the on-off valve closes, the water injection nozzle is connected to the water supply pipe. and an air pipe for supplying purge air to the return water passage, and the return wood pipe connected to the return water passage is provided with a flow rate adjustment valve for adjusting the discharge amount of the return water,
Moreover, the complete evaporative gas cooling tower includes a gas temperature detector provided at the gas outlet and a valve controller that controls the multiple valves based on a temperature detection signal from the detector.