JPS6251128B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for spraying a slurry or aqueous solution of a chemical such as slaked lime into exhaust gas to remove harmful gases such as hydrogen chloride from the exhaust gas.

As a method for removing harmful gases (mainly hydrogen chloride and SOx) from exhaust gas generated from garbage incinerators,
A semi-dry method is known in which a slurry or aqueous solution of a harmful gas removal agent is sprayed into exhaust gas. In this semi-dry method, the removal agent is made into a slurry or aqueous solution and is sprayed into the exhaust gas in a reaction tower.The spray agent reacts with harmful gases in the exhaust gas, and the reaction product is dried by the heat retained in the exhaust gas. It is removed from the exhaust gas as

FIG. 1 shows a conventional chemical spraying device installed in the reaction tower mentioned above, which is fixed at a position (for example, inside the upper part of the reaction tower) where the chemical is sprayed into the exhaust gas in the reaction tower. The device includes a device main body 1, and a rotating disk 3 that is arranged under the device main body 1 with a gap G of, for example, about 10 mm and rotated at high speed by a central rotating shaft 2 passing through the main body 1. The main body 1 has a chemical supply section 5 (the upper part is closed by a lid 6 and the lower part is closed by an outflow hole 7), into which a harmful gas removal agent, such as slaked lime slurry, is supplied at a small flow rate such as dripping through an introduction pipe 4. The rotary disk 3 is provided with an inlet opening 8 for the removal agent flowing down from the agent supply section 5 and a receiving chamber 9 for the inflow agent. At the same time, a plurality of spray nozzles 10 are provided that spray the medicine that has entered the chamber from the outer circumference of the disk into the exhaust gas by rotational centrifugal force.

In this chemical spraying device, a removal agent such as slaked lime slurry is continuously supplied in small quantities into the rotating disk 3 from the main body supply section 5, and is sprayed from the spray nozzle 10 using the centrifugal force generated by the high-speed rotation of the disk as the driving force. Since it is spouted out, when the disk 3 rotates at high speed, the inside of the disk becomes negative pressure, and therefore the surrounding exhaust gas is sucked into the rotating disk 3 through the gap G between the device main body 1 and the rotating disk 3, The liquid is ejected from the nozzle 10 together with the removal agent. However, since exhaust gas contains carbon dioxide,
When the chemical is slaked lime slurry, this slaked lime and carbon dioxide gas in the exhaust gas chemically react to form calcium carbonate, and the calcium carbonate immediately after its formation adheres to the inner surface of the nozzle 10 and blocks the nozzle. It was occurring.

This invention was made with the aim of eliminating the above-mentioned drawbacks, and is designed to control the internal pressure inside the rotating disk during high-speed rotation so that the surrounding exhaust gas is not drawn into the rotating disk when the disk rotates at high speed. It is characterized by maintaining a pressure higher than the internal pressure of the reaction tower in which the main body is installed, preferably a pressure higher by about 0 to +10 mmAq.

Hereinafter, one embodiment of the device of this invention will be described with reference to the drawing in FIG. 2. This embodiment is a drug spraying device similar to that shown in FIG. ), the drug supply section 5 of the device main body 1 or the device main body 1 and the rotating disk 3
An air blowing pipe 11 for introducing air from outside the reaction tower is connected to the gap G (the example shows the former case), and the air inside the rotating disk 3 is caused by air pressure blown from here. It is characterized by maintaining the internal pressure during high-speed rotation at a pressure higher than the internal pressure of the reaction tower in which the apparatus main body 1 is installed (preferably a pressure higher by about 0 to +10 mmAq), and the control of the disc internal pressure is performed by the rotating disc 3. The air pressure detector 12 disposed above the drug inflow opening 8 detects the air pressure supplied into the rotary disk 3, and this detection signal is used to control the adjustment valve 1 of the air pipe line 13.
This is done by controlling 4. It should be noted that there is also a method of maintaining the disk internal pressure as described above that can be easily carried out without using the pressure detector 12.
That is, since the rotating disk 3 rotates at a constant speed, a substantially constant negative pressure is generated inside the rotating disk 3. Therefore, if air corresponding to this constant negative pressure is supplied at a constant pressure and constant flow rate, the internal pressure of the rotating disk 3 will be 0 to +10 higher than the reaction tower internal pressure.
Can be maintained at pressures as high as mmAq. The reason why the internal pressure in the rotating disk 3 during high-speed rotation is set to be about 0 to +10 mmAq higher than the reaction tower internal pressure is that if the internal pressure of the rotating disk 3 becomes too high, the chemical supplied in the rotating disk 3 will be affected by rotational centrifugal force. This is because problems such as poor spraying may occur.

Since the chemical spraying device for removing harmful gases from exhaust gas according to the present invention is as described above, the problem of surrounding exhaust gas being drawn into the disk during high-speed rotation of the rotating disk is prevented, and the exhaust gas is prevented from entering. The conventional nozzle clogging problem caused by this can be easily solved. In other words, when we actually operated and tested the device of the present invention, no nozzle blockage occurred even after three months had passed (there have been cases where nozzle blockages occurred in about two weeks with conventional devices). .

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a main part showing a conventional chemical spraying device for removing harmful gases from exhaust gas, and FIG. 2 is a sectional view of main parts showing a chemical spraying device for removing harmful gases from exhaust gas according to an embodiment of the present invention. It is. 1... Apparatus body, 2... Central rotating shaft, 3... Rotating disk, G... Gap, 4... Drug introduction pipe, 5
...Drug supply section, 8...Drug inflow opening, 9...
Receiving chamber for inflow drug, 10... Spray nozzle, 11...
...Air blowing pipe, 12...Air pressure detector.

Claims (1)

[Claims] 1. A device main body that has a drug supply section and is installed at a drug spraying position in the reaction tower, and is rotated at high speed by a central rotating shaft that is arranged with a gap below the device main body and passes through the main body. Consists of a rotating disk,
This rotating disk has an inflow opening for the medicine flowing down from the medicine supply section and a receiving chamber for the inflowing medicine, and is equipped with a plurality of spray nozzles that spray the medicine that has flowed into this chamber from the outer circumferential part by rotational centrifugal force. In a spraying device for a chemical to remove harmful gases from exhaust gas, an air blowing pipe is connected to the chemical supply section of the device main body or to the gap between the device main body and the rotating disk, and the air pressure blown from there is used to spray the chemical. An agent for removing harmful gases from exhaust gas, which maintains the internal pressure within the rotating disk at high speed rotation at a pressure higher than the internal pressure of the reaction tower in which the main body of the device is installed, preferably at a pressure higher than about 0 to +10 mmAq. Spraying device.