SU1694662A1 - Method of graphitization of carbon products - Google Patents

Abstract

The invention relates to electrical engineering and can be used for graphite carbon products. The purpose of the invention is to increase the yield by reducing the temperature difference over the core section. The method of graphitization of carbon products includes their laying in the core, installing the core in the furnace between the electrodes, filling the gaps between the core and electrodes with coke and thermal soot, heating up to 2800-3000 ° C and cooling, while choosing a cross-section of the core and the contacting part of the electrode is chosen from the ratio of 0.93-0.99. This method of graphitization allows one to reduce temperature drops over the core section. 1 dw., 2 tab.

Description

The invention relates to electrical engineering and can be used for graphitizing carbon products.

The purpose of the invention is to increase the yield by reducing the temperature difference over the core section.

The drawing shows a graphitization furnace.

A graphitization furnace for carbon-graphite products includes a heat insulating body 1, current-carrying electrodes 2 located therein, a core 3 assembled from carbonaceous products, carbon bed 4, heat insulation 5, for example carbon black. The core 3 is laid directly on the plywood layer 6. The core consists of packages of 7 carbon products, which are separated from each other by coke backfill 8. Dilatometric thermometers 9 are placed in the central package to measure the temperature. Core cross-sectional area

is FI, and the area of the current lead electrode is F2.

EXAMPLE 1. Sheets of plywood or thick paper are laid on the layer of bottom filling 4, and then packages 7 are placed between the electrodes mounted into the furnace end walls on blocks of burned brush semi-finished product of size 30x38x95 mm. The cross section of the electrodes is 400x400 mm. Package length 475 mm. The blocks are placed on a large area with a long side parallel to the axis of the furnace. The width of the stack 10 blocks, height - 13 blocks a multiple of the width and height.,

The section of the package assembled from blocks is 380x390 mm. The length of the furnace set 9 packages. The ratio of the core section to the electrode section is 0.93. The gaps between the packages, packages and electrodes are filled with coke backfill 8 with a grain size of 8-10 mm. Using the template, the core is surrounded by coking, previously in the central package by placing two dilatometric thermometers 9 through graphite sighting tubes to measure the temperature in the center of the package and on the periphery. Then the furnace to the upper level is filled with thermal soot, connected to furnace transformers and heat treated to 2800-3000 ° C.

After the operation, the furnace is turned off, cooled, unloaded, the products are screened by appearance and physicomechanical properties, and the output of the suitable one is determined.

PRI mme R 2. The furnace is loaded analogously to example 1 with fired blocks of the same size, but the width and height of the packages are placed on one row of blocks more, and the cross-section of packages multiple to the width and height of the blocks is already 418x420 mm. The cross section of the core to the cross section of the electrodes is 1.097. PRI me R 3. The furnace is loaded similarly to example 1, but using a size of 20x38x95 mm. The package section is a multiple of the block sizes and is 380x400 mm. The ratio of the core section to the electrode section is 0.95.

EXAMPLE 4. The process is carried out analogously to example 2, but the core is made up of blocks of size 20x38x95 mm. The core section is 418x400 mm. The ratio of the core section to the electrode section is 1.045.

PRI me R 5. The furnace is loaded similarly to Example 3, but the stack height is placed one row of blocks smaller. The packet cross section in this case is 380x380 mm. The ratio of the core cross section to the electrode cross section is 0.90.

PRI me R 6. The furnace is loaded analogously to example 1 in blocks of size 19x80x80 mm. The package section is a multiple of the block sizes and is equal to 400x399 mm. The ratio of the core section to the electrode section is 0.99.

Example. The process is carried out analogously to example 6, but the width and height of the core are laid on one row of blocks more. The core section is 400x418 mm, 1 The ratio of the core section to the electrode section is 1.045,

PRI me R 8 (known). Burnt blocks are placed in packages analogously to example 1, a multiple of the width and height of the blocks, but with a much larger total cross section,

than the cross section of the electrodes (494x480 mm). The ratio of the core section to the electrode section is 1.48,

The data in examples 1-8 are presented

in table 1 and 2.

Analyzing the data of Tables 1 and 2, we can conclude that when the ratio of core sections and electrodes is greater than 1, the furnace load increases, but the consumption of energy costs (specific energy consumption) also increases - examples 2, 4, 7, 8, and the duration of heat treatment , which leads to lower furnace performance. In addition, marriage is increasing due to lower

heat treatment temperatures corresponding to the peripheral core layer protruding beyond the electrode cross section.

When the ratio of the core section to the electrode section is 0.93-0.99 (examples 1, 3, 6)

a positive effect is achieved. The process of graphitization is the most stable due to the minimum temperature differences. The yield increases due to the improvement of the characteristics of hardness, specific

electrical resistivity, reduction of defects in appearance (cracks, gout, warping).

A decrease in the Fi / F2 ratio below 0.95 (Table 1, Example 5) leads to a decrease in the furnace load and a decrease in the furnace performance.

This method of graphitization allows, in comparison with the known method, to stabilize the process by reducing the temperature

drops in the core section from 340 (known) to 115-130 ° С (examples 1, 3, 6), which leads to an increase in the yield of a suitable semi-finished product (by 35%).

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Claims (1)

Invention Formula The method of graphitization of carbon products, including their laying in the core, the installation of the core in the furnace between the electrodes, filling the gap between the core and the electrodes with coke and thermal soot, heating up to 2800-3000 ° C and cooling, characterized in that, in order to increase the yield by reducing the temperature difference over the core section, the cross-section of the core and the contacting part of the electrode is selected from the ratio 0 93-0.99.