SU934167A2 - Rotary kiln for calcining loose material - Google Patents

Description

The invention relates to rotary kilns and can be used in the electrode, electric arc and metallurgical industries for calcining anthracite, petroleum and pitch coke. In addition, the rotary kiln can be used in other areas of the industry where, according to the conditions of production, heat treatment must be carried out in a special gas environment.

According to the main author. St. No. 72795. a known furnace for calcining bulk material which contains a drum with a channel in the wall in communication with the inside of the drum from the side of the hot head and with a smoke hog from the side of the cold head, with an opening in the wall of the drum for supplying air to the channel.

This embodiment of the furnace reduces the waste of material in the drum,

prevent pollution of the atmosphere, increase the thermal efficiency of the OZ furnace.

However, the known design of the furnace does not allow reducing the waste of the material during its cooling. This is explained by the fact that cold air, drawn in through the discharge chute and furnace seals, flows along the refrigerator and, hitting the front of the refrigerator, where the temperature is 600-700 ° C, contributes to the combustion of the material. Thus, two opposite processes occur simultaneously in the refrigerator, one of which contributes to the heating of the material, and the other to its cooling. As a result, at a certain length of the refrigerator, the material is not cooled at all, but only the heat produced by the combustion of the material occurs.

In addition, the known construction does not allow the use of the physical heat of cooled coke for

intensification - afterburning of particles of material carried by the gas stream, as well as to increase the thermal efficiency of the furnace.

The aim of the invention is to reduce the loss of material and increase the thermal efficiency of the furnace.

This goal is achieved by the fact that in a rotary kiln the burner is placed along the axis of the furnace toward the cold head, and the air inlet is located between the hot head and the nozzle of the burner.

Due to such a design, coke pre-cooling is performed in the volume of the rotating drum; as a result, coke waste is reduced during the cooling process, and the cold air entering the channel is preheated, taking on the heat of the cooling hot material, thereby intensifying the process of volatile combustion. substances and particles of coke entering the channel, and the thermal efficiency of the furnace increases.

FIG. 1 and 2 show the proposed oven, longitudinal section.

The furnace contains a rotating drum 1, which is inclined to the horizon. Upper end drum

I connected with a cold head 2, which has a smoke hole 3 and on the opposite side, a hot head 4, in which the burner 5 is installed. The working space of drum 1 is isolated from the cold head 2 and the horn 3 by a partition 6. Through the cold head 2

and the partition 6 passes the loading chute 7- Hot head t connected to the refrigerator 8 equipped with a discharge chute 9- Drum 1 is equipped with bandages 10, mounted on supports

II and is equipped with a drive 12. The drum 1 is lined from the inside with refractory shaped blocks 13 forming the channels I passing through the entire drum from the cold head to the hot one. The channels k are connected to the inside of the drum by the inlet openings 15. with the hot head by openings 16 and the atmosphere of openings 17 with valves 18.

The placement of the burner, holes and channels determine the position in the furnace of the heating, calcining and cooling zones. The area of bar1 1 from chute 7 to holes 15 is a preheating zone. The area from the openings 15 to the exit end of the burner 5 is the calcining zone and the section from the burner 5 to the hot head 1 is the cooling zone.

The furnace works as follows.

Through the loading chute 7, the material enters the rotating drum 1 and, due to the slope and rotation of the drum, moves through the preheating zone, where the material is heated by

flue gases moving through the channels and lose the bulk of the volatile substances that create a reducing atmosphere in the drum and enter the holes 15.

When moving through the calcination zone, the material is heated to the final temperature due to the radiation of the flame, and then cooled in the cooling zone and enters the hot zone.

head 4. Cold air is sucked into channels 14 through openings 16 and 17, passes into the cooling zone, where it is heated by the heat of hot material, mixed with hot gases coming from the preheating and calcining zones through openings 15 and, due to preliminary heating, provides complete burning of both volatile and small particles of coke.

By changing the position of the valves 18, it is possible to change the vacuum value in the hot head k, to achieve a small inflow of combustion products into it to prevent air from the refrigerator and leaks from flowing into the hot head and completely eliminate the possibility of burning the cooled material. The material coming out of the hot head enters the refrigerator 8, and from there it is discharged from the furnace through the discharge chute 93 due to the fact that the temperature of the material (coke) entering the refrigerator is already significantly lowered.

the cooling zone of the drum, the leakage of air through the chilling of the refrigerator can no longer cause the burning of coke.

Thus, due to the features of the proposed design, it becomes possible to completely eliminate the waste of material (coke) during the cooling process and intensify the burning process of volatile and coca particles, thereby reducing environmental pollution and increasing the thermal efficiency of the furnace.

Claims (1)

1. USSR author's certificate number 72795, to. T 27 B 7/0, 1977. L 8 x FIG. 2