SU425030A1 - FURNACE FOR FIRING MATERIAL - Google Patents

Description

one

The invention relates to the building materials industry, namely to firing furnaces for bulk material.

A famous kiln for firing loose material, containing heat-insulated Hiaxtu, hollow ceramic core, loading and unloading devices, a device for burning fuel, a device for selecting a coolant.

The aim of the invention is to intensify the burning process.

This is achieved by the fact that the shaft is made in the form of located one above the other and communicating, among themselves, channels of rectangular section of trapezoidal chambers narrowed downwards. The outer surface of the core corresponds to the configuration of the mine walls in each section. The inner core cavity is divided in height by diaphragms, and each of the chambers thus formed is connected through channels in the core walls to the working space of the furnace. The fire chamber is built in the lower chamber. The coolant extraction device is made in the form of boxes arranged one inside the other, with openings in the walls of the inner box with a diameter increasing to the center of the furnace.

FIG. 1 shows the proposed furnace in section; in fig. 2 is a section along A-A in FIG. one;

in fig. 3 is a schematic of the device for the selection of coolant and a section along BB.

The device consists of a heat-insulated shaft 1 with a core 2 made of refractory material located inside it, loading 3 and unloading 4 devices, devices for burning fuel (burners) 5, 6 and 7, device 8 for taking coolant. From the outside, adjacent to the mine are located

two fireboxes that communicate with the working space of the furnace by tangential channels 9, 10, AND and vertical channels 12.

Kern 2 height divided by partitions

chambers 13, 14, 15, which communicate with the working space of the furnace by radial channels 16 and tangential channels 17, 18, 19, and between them by a hole 20. Burner 7 is fixed on the mechanism 21 with a drive 22..

The device for extracting the coolant consists of an outer duct 23, an inner duct 24 with openings 25 whose diameter increases to the center of the furnace, an air supply duct 26 with a branch pipe 27 and a rotary valve 28. The duct 24 is connected to a collector 29 or to a fan 30 supplies gases to the collector 31. The amount of gases is controlled by the valve 32. The material is discharged from the furnace through sluice gates 33 on

conveyor 34. Fuel to burner 7 is supplied from line 35. Secondary air to chamber 36 is supplied from manifold 37, its quantity is controlled by valve 38. Pipelines 39 and 40 serve to supply cooling air to the core.

The coarse fraction (for example, 40; -80 mm) through the charging device 3 enters the annular space into the furnace heating zone, at half the height of which a part of the gas flow rising from the kiln firing zone is discharged through the openings 16 into the chamber 13, from where they come into the device 8. Lowering, the material passes the furnace heating zone, takes heat from gases that are mixed in countercurrent with it, which are cooled to 150-200 ° C.

In device 8, gases move along duct 24, in which they are mixed with air entering through openings 25 from duct 23. At the same time, the gas temperature decreases from 600-700 ° C at the entrance to the duct 24 to 400-450 ° C at the exit from it . A mixture of gases of a given chemical composition is sucked from the device 8 by the fan 30 and injected into the collector 31, from where it is distributed to the burners 6 of the upper tier. The control of the predetermined temperature and chemical composition of the gases at the exit of the device 8 is carried out by means of the butterfly valves 28 and 32.

Heated to 850–900 ° C, the material from the preheating zone is lowered into the burning zone, in which it passes two constrictions of the shaft in a countercurrent with gases. In a shaft constriction, the gas velocity increases, and the rate of heat transfer from gases to the material increases accordingly. As a result, the temperature of the surface layers of the material for some time approaches the temperature of the gases. Gases at 1200-1250 ° C enter the clamp from the side of the mine and from the side of the core, due to which their temperature is the same across the cross-section of the mine at the place of the pinch.

Pass the clamp, the material enters the conical part of the working space, where the velocity of gases is lower. At the same time, the rate of heat removal to the center of a piece of material becomes higher than the rate at which heat is supplied to its surface, and the temperature of the surface of the material decreases and rises in the center. As a result, the surface of the material is not burned through, and the average temperature of the piece of material increases continuously.

Having passed the second clamp, the material is lowered into the conical part of the shaft, where gases flow in the flow path with it. Due to the direct movement of the gases and the material, the material at the end of the burning zone is not burned, since the temperature difference between the gases and the material decreases as the material is lowered.

Further, the material enters the third clamp, in which the temperature difference between the gases and the material is set close to zero, and their absolute value is close to 1000 ° C. After pressing, the material is intensively cooled with moving lower air. Lowering, the product of firing enters the unloading device 4, which transports it through a sluice gate 33 to the ring conveyor 34. The air heated in the cooling zone and

part of the furnace gases through the channels 19 are injected by the burner 7 and enter the chamber 15, into which fuel is supplied from the pipeline 35 via the burner 7. Since the combustion of the combustible mixture occurs with a significant content of inert gases (nitrogen, water vapor, carbon dioxide), the temperature in chamber 15 is maintained at 1; 250–1300 ° C. From chamber 15, one part of the combustion products through the tangential channels 18 enters the annular space of the burning zone at the level of the lower rush of the fireboxes, and the other part through the opening 20 into the chamber 14, and through the tangential channels 17 enters the burning zone at the level of the upper wind of the combustors.

Combustion of gaseous or liquid fuels in peripheral fireboxes with burners 5 takes place with the use of inert (kiln) gases injected into the fireboxes through channels 9 and 12. Thanks to the use of inert

gases, the temperature of combustion in the peripheral furnaces is maintained at 1250-1300 ° C. The secondary air under pressure enters the cooling zone (chamber 36) from the manifold 37, and its quantity is regulated at

damper 38. Part of the secondary air through pipelines 39 and 40 is supplied to core 2, where it is heated to 200-250 ° C and used to burn fuel in burner 7. A branch pipe serves for the extraction of gases from the furnace.

Hatches serve to remove dust from channels 12.

When a fine fraction material is fed into the furnace (for example, 1-5; 3-10; 5-15 mm), the aerodynamic roasting and

mode of operation of the boot device. The rate of movement of gases in the furnace clamps is set close to the soar rate of the particles of the calcined fraction. The loading device 3 is switched to the rotation mode.

the material distributor at a constant speed, and the lower valve for the dispenser mode with pulsating material feed.

Subject invention

Furnace for burning loose material containing a heat-insulated shaft, a hollow ceramic core, loading and unloading devices, a device for burning fuel, a device for selecting a coolant, characterized in that, in order to intensify the process of burning, the shaft is made one above the other and interconnected channels of rectangular cross section of trapezoidal shaped cells narrowed downwards; the outer surface of the core corresponds to the configuration of the mine walls in each section; the inner core cavity is divided in height by the diaphragms, and each of the chambers thus formed is connected through channels in the core walls to the working area of the furnace, and

the fire chamber is built in the lower chamber; The device for selecting the heat transfer fluid is made in the form of boxes arranged one in another, and holes with a diameter increasing towards the center of the licchi are formed in the walls of the inner box.

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