SU1495294A1 - Method of firing carbonaceous materials and hearth furnace for performing same - Google Patents

Abstract

The invention can be used in the manufacture of anodes and graphitized electrodes, as well as for the manufacture of carbon structural products. The purpose of the invention is to reduce the grinding of calcined material by eliminating thermal shock and mechanical abrasion. The material is fed to the periphery of the furnace hearth and heated in layers, and a layer of raw raw material is fed to the layer of material heated to 250-600 ° C with the number of layers 2-6. Gradually move the material to the center of the furnace and maintain at a final temperature of 1250-1500 ° C. The hearth of the furnace includes a hearth with a slope from the periphery to the central extracting shaft, mounted on roller supports rotatably around a vertical axis.

a vault with 2-6 telescopic pipes for feeding material that are evenly spaced around the periphery of the vault at the same distance from the center of the furnace

scrapers installed above the bottom, to move the material to the holding shaft, and the chimney. The invention allows to increase the content of the fraction * 986 mm to 36-39%. 2 sp.f-ly, 3 ill., 1 tab.

Description

The invention relates to the technology of calcining carbon materials and can be used in the manufacture of anodes and graphite electrodes, as well as in the manufacture of carbon structural products.

The purpose of the invention is to reduce the grinding of calcined material by eliminating thermal shock and mechanical abrasion.

FIG. 1 shows schematically a hearth furnace, a section; FIG. 2 shows a section A-A in FIG. one; on

FIG. 3 - heating rate of coke by the known and proposed methods.

The hearth furnace contains a roof 1 with a chimney 2, a hearth 3 mounted on Katkovy supports 4 rotatably around a vertical axis, scrubbers 5 for moving the material along the bottom to the center, to the shaft 6 of the vanes. Bottom 3 is driven into rotation by an electric motor (not shown) using gear gear 7.

A discharge table 8 is installed under the shaft of 6 p .1. Supports. In the roof of the furnace 1, nozzles 9 are installed for feeding

co tc

with

four

fuel gas and diffusers 10 days air supply to the furnace. In the furnace vault, holes 11 are made uniformly around the periphery for the installation of telescopic tubes 12, which serve to supply raw materials to the furnace from the intermediate hopper 13.

The method of calcination in the proposed furnace is implemented as follows.

Crude coke is fed through several, for example, three, telescopic tubes 12 into a preheated oven. Telescopic tubes 12 are located at the same distance from the center of the bottom. The number is telescopic., Is determined by the speed of rotation of the bottom, with its increase the number of mobile pipes is more than five-1-; there is 1, with a decrease - meg. d). Because telescopic tubes are placed on. the same length from the center of the hearth, then to ensure the identical coke layer that is poured out from each pipe, the coke consumption is also the same. The consumption of material for a known furnace and the proposed one is 17.6-25 t / h, while the consumption of material through each pipe is determined by the formula

-2

T / H

where O is the consumption of coke j p. number of pipes,

Example 1. Crude coke with a fraction content of 6 mm 55% is fed into the preheated1, then up to 1400 ° C, the furnace, rotating at a speed of 13 rpm, in color. teleskosh-gchesk1M pipes simultaneously. When the monolayer of coke, filled with the first telescopic tubes, is moved to the second tube, it is heated up (ms. Coke) to the PtorO1 telescopic tube to reduce the amount of coke that protects the previous coke from overheating. The thickness of each coke poured in monolayer is 150 mm: The scrapers move the coke to the holding shaft, while as the coke moves, it is heated to the final calcination temperature of 1400 C.

The table presents data on the fractional composition and the content of large fractions of coke, calcined according to the proposed method to

the proposed furnace, and the results of comparative examples.

The conditions for the implementation of the following examples 2 and 3 and example 4 (by a known method) are identical to those of example 1.

From the data presented in the table it follows that the content of coke fractions of 6 mm increases to 36-39%, which is 2-5% higher than their content during calcination of coke by a known method and indicates a decrease in the calcination of the calcined coke.

The coke layers are backfilled to the hearth continuously and simultaneously from all telescopic tubes, but in such a way that the backfill from each Subsequent telescopic tube is filled with a layer formed by backfill from the previous tube. Subsequent backups of new layers on top of existing ones allow staged heating and cooling of coke, thereby eliminating a high heating rate, and by the time the total backfill (layer) approaches the first scraper — have an average layer temperature of 600–700 ° C, the scraper turns over

layer and heat exposure; subjected to its lower part. During the second turn of the bottom, coke is heated to the temperature of the prokalai due to the heat of combustion of the volatile components

the most volatile substances are released in the coke heating zone of 600-900 C. To evenly heat the coke, the scraper is turned over several times.

mi At the same time, each scraper shifts a layer of coke by a certain step and the last scraper drops a layer of coke into the mine, holding.

Curve 1 illustrates the average rate of heating of coke by a known method, curve 2 - on the proposed.

Ia, t curve 2 shows the temperature field on the coke layer with layer-by-layer loading. Curve 2 shows that a gradual build-up of a layer of coke not only prevents the lower layers from intense heating (beyond 1 from thermal shock), but also provides intermediate cooling. The average heating rate of coke is 50-80 ° C / min, except for the first layer, in which the heating rate is high (l / 250 C / min), but not described, since at this speed

Claims (2)

the heating is not yet evolved from the coke volatile, and the subsequent backfilling eliminates thermal shock, as a result of which the coke is not crushed. Claim 1. Method of calcining carbon materials in a rotary hearth furnace at 1250-1500 ° C, including feeding the material to the periphery of the furnace bottom, heating it, moving to the center of the furnace and holding at a calcination temperature, characterized in that, in order to reduce the calcined grinding material by eliminating thermal shock and mechanical abrasion of it, the carbon material is fed in layers, and a layer of raw material is fed to the layer of material heated to 250-600 C with the number of layers 2-6. 2. Bottom furnace for the calcination of carbon materials, including a bottom hearth with a slope from the periphery to the central holding shaft, mounted on Katkov supports rotatably around a vertical axis, a roof equipped with a telescopic material supply pipe at the periphery, scrapers mounted above the bottom of the material to the mine shaft, and the chimney, characterized in that, in order to reduce the crushing of the calcined material by eliminating thermal shock and mechanical operation, tyranny, it has us further telescopic tube in an amount of 1-5, wherein the tubes are arranged uniformly around the periphery of furnace roof on odyutakovom distance from its center. Telescopic number pipes Heating temperature monolayer of coke, C Calcination temperature coke with Oven rotation speed rev / h Thickness of the bed coke mm The content of the fraction more 6 mm in raw coke,% Fraction content more 6 mm in the calcined coke, 1400 13 300 55 34 fS Yif-w iVi 9l / t. / Jjl "Mtf 15/