JP3271385B2 - Combustible exhaust gas combustion 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 facility for preventing flashback from a combustion chamber when combustible exhaust gas generated in reduction smelting is released to the atmosphere after combustion.

[0002]

2. Description of the Related Art Generally, in a reduction smelting method, a large amount of carbon monoxide is contained in exhaust gas from a reduction furnace in order to reduce metal oxides such as zinc and lead in a reducing atmosphere. If this flammable exhaust gas containing a large amount of carbon monoxide is released into the atmosphere as it is, an explosion occurs in a chimney or a flue or harmful carbon monoxide is scattered around. For this reason, carbon monoxide in the exhaust gas is burned, converted into harmless carbon dioxide, and then released into the atmosphere.

By the way, when carbon monoxide comes in contact with oxygen at a temperature of, for example, 800 ° C. or less, it reacts rapidly, causing a so-called carbon monoxide explosion. For this reason, it is usual to control so that the pressure between the combustion chamber and the reduction furnace is always positive. Then, a perforated plate called a punch plate is installed at the entrance of the combustion chamber, and the inflow speed of the exhaust gas into the combustion chamber is usually higher than the flashback speed.

[0004] As a method of mounting the punch plate,
There is a method in which the entrance flue of the combustion chamber is made vertical and the punch plate itself is mounted horizontally, and a method in which the entrance flue of the combustion chamber is made horizontal and the punch plate itself is mounted vertically. However, if the entrance flue is horizontal and the punch play is provided perpendicular to the horizontal flue, the smoke ash in the exhaust gas accumulates in the flue in front of the punch plate. The opening is closed. For this reason, it is common to make the entrance flue vertical and attach the punch plate horizontally. However, even with this method, the clogging of the opening due to the adhesion of smoke ash cannot be completely prevented.

[0005] As the opening of the punch plate closes, the gas pressure in the system increases, and the exhaust gas of the reducing furnace is liable to be blown out from various places. Therefore, the amount of exhaust gas generated in the reducing furnace must be reduced. Become. As a result, operating capacity must be reduced. To prevent this, the opening of the punch plate and the inside of the flue must be cleaned as appropriate, and the smoke ash must be discharged out of the system.However, there is a risk of explosion and poisoning due to carbon monoxide in the exhaust gas present in the flue. In addition, the cleaning has to be performed after stopping the operation, and a decrease in the operation degree cannot be avoided. For this reason, development of a combustible exhaust gas treatment facility that enables the punch plate to be easily cleaned during operation has been awaited.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a combustible exhaust gas treatment facility capable of cleaning a punch plate without stopping the operation of a reduction furnace. I do.

[0007]

Means for Solving the Problems The flammable exhaust gas combustion equipment of the present invention for solving the above-mentioned problems includes a reduction furnace, a device for removing smoke ash in the flammable exhaust gas generated in the reduction furnace, and a flammable exhaust gas. In a combustible exhaust gas treatment facility comprising a combustion chamber for combustion, an inlet flue of the combustion chamber is made vertical, and at the vertical portion, at least two punch plates rotatable like a butterfly valve function as a punch plate. The punch plate is provided so as to be horizontal when it is in the position.

[0008]

The punch plate used in the present invention is rotatable like a butterfly valve, and the number of openings provided in the punch plate and the area of each opening are determined according to the type of combustible gas. This is because the purpose of providing the punch plate is to make the inflow speed of the flammable exhaust gas into the combustion chamber equal to or higher than the flashback speed as described above, and this flashback speed depends on the gas composition in the flammable exhaust gas. Because it is different.

In the equipment of the present invention, the provision of the punch plate so that the state when functioning as the punch plate is horizontal not only reduces the amount of smoked ash but also rotates the punch plate. This is for dropping the smoke ash deposited on each punch plate downward. The reason why at least two such punch plates are provided is to ensure that one punch plate always functions as a punch plate by rotating the punch plates alternately.

The operation of the apparatus of the present invention will be described. First, the lower punch plate is turned over to remove the smoke ash deposited on the punch plate, and then returned to the original position. Then, the upper punch plate is inverted, and the smoke ash deposited on the punch plate is wiped off and returned to the original position. At this time, since the smoke ash removed from the upper punch plate accumulates on the lower punch plate again, the dust is removed again by reversing the lower punch plate.

Basically, the operation of reversing the punch plate may be performed when the hole of the punch plate is closed, but if an excessive amount of smoke ash is deposited on the punch plate, the operation procedure described above is performed. When the upper punch plate is turned over, a large amount of smoke ash is quickly blown off onto the lower punch plate, and there is a risk that the hole of the lower punch plate is instantly closed. In addition, smoke ash can be easily removed by simply rotating the punch plate at the beginning of the accumulation, but if left for a long time, it may be solidified, and it may not be possible to remove the smoke ash by simply rotating the punch plate. Therefore, a series of the above operation procedures should be performed at a frequency at which the amount of smoke
It is desirable to carry out continuously.

As described above, in the equipment according to the present invention, even if one of the two punch plates is inverted, the other punch plate is at the proper position, and it is possible to prevent flashback from the combustion chamber. The dust accumulated on the punch plate can be easily cleaned during the operation without stopping the furnace operation.

[0013]

Next, an embodiment of the present invention and a conventional example will be described. (Example) As a reduction furnace, inner diameter is 1.5m, height is 2.8
m and a settler with an inner diameter of 1.5 m and a length of 5.25 m, and a condenser with an inner size of 5 m, a width of 1 m and a height of 0.58 m after the settler. 1m wide, 0.8m deep, height just above the discharge end of
A 2.6m offtake is provided, and after the offtake, a 1.5m wide, 1m deep, 3m high dust chamber with an inner width of 0.8m
m, length 4.7m, height 1.7m combustion chamber and control chamber through combustion damper with 0.5m inner diameter pipe,
As shown in FIG. 1, the inlet pipe of the combustion chamber is provided with an inlet pipe 2 vertically below the combustion chamber 1, and a hole having a diameter of 35 mm is formed in a vertical portion of the inlet pipe 2 as shown in FIG. Two zinc plates 3 opened so as to be distributed as evenly as possible at 30 locations were rotatably mounted at intervals of 0.6 m to constitute a zinc recovery facility. The exhaust gas from the combustion chamber was cooled by a water-cooled jacket-type cooler, dust-removed by a bag filter with a heat-resistant temperature of 250 ° C, and released into the atmosphere.

Using this zinc recovery equipment, coke breeze was introduced into the reaction tower by a burner provided at the top of the reaction tower of the reduction furnace at 200 K.
g / H and industrial oxygen (purity 90%) were blown in at a rate of 292 Nm ³ / H. The coke breeze was mixed with oxygen and blown into the furnace. Next, after confirming that the oxygen concentration was almost 0% and the pressure in the system was stabilized, the blowing amount of coke breeze was increased to 300 kg / H. The amount of oxygen was reduced to 275 Nm ³ / H, and these operating conditions were maintained until the reactor condition was stabilized. Next, the zinc-containing raw material was set to 250 kg / H, the blowing amount of coke breeze was set to 400 kg / H, and the industrial oxygen amount was blown to 365 Nm ^3.
/ H and normal operation was performed for 7 days. During this time,
The punch plate was rotated twice each time to remove smoke ash adhering to the punch plate. Then, smoke ash was appropriately taken out of the system from a chute provided in a flue below the punch plate. The amount of generated smoke ash was 0.32 tons in total. During the operation period, there was no trouble caused by blockage of the punch plate.

(Conventional example) A test operation was performed in the same manner as in the example except that the number of punch plates was one and the plate did not rotate during the operation period. It was found that the pressure in the system began to increase four days after the start of the operation, and that the holes in the punch plate could not be closed. Then, in half a day, the pressure inside the system became too high and the operation had to be reduced, and on the second day, the operation was stopped and the holes in the punch plate were cleaned. At this time, one-third of the hole was completely closed with smoke, and a large amount of smoke had adhered to the remaining two-thirds.

[0016]

According to the present invention, the dust accumulated on the punch plate can be safely removed without causing a flashback of the flammable gas without stopping the operation of the reduction furnace.

[Brief description of the drawings]

FIG. 1 is a diagram showing an arrangement of a combustion chamber, an inlet pipe, and a punch plate used in an embodiment of the present invention.

[Explanation of symbols]

1-- Combustion chamber, 2--Inlet piping, 3--Punch plate, 4--Stopper, 5--Rotating shaft

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F27D 17/00 F23G 7/06

Claims (1)

(57) [Claims] In a flammable exhaust gas treatment facility comprising a reduction furnace, a device for removing smoke ash in combustible exhaust gas generated in the reduction furnace, and a combustion chamber for burning the combustible exhaust gas, The entrance flue is made vertical, and at least two punch plates rotatable like a butterfly valve are provided in the vertical portion so that the punch plates are horizontal when functioning as a punch plate. Combustible exhaust gas combustion equipment.