Electric furnace for the calcination of carbonaceous materials

Details Electric furnace for the calcination of carbonaceous materials Electric furnace for the calcination of carbonaceous materials

1981-02-08

1982-11-02

Garris, Bradley

Distillation: apparatus

Apparatus

Systems

201 19, 201 27, 201 34, 202 99, 202215, 373115, 373110, C10B 300, C10B 1900, C10B 2100

Patent

active

043572103

DESCRIPTION:

BRIEF SUMMARY
The new furnace which is the object of the invention is of the type in which the charge to be treated acts as an electric resistance and is heated by passing a current directly through it. This furnace is suitable for the calcination of carbonaceous materials, in particular anthracite, with the aim of eliminating the volatile materials which they contain.
Electric furnaces for the calcination of anthracite by passing a current through the charge, of the type described in the left-hand column on page 1 of French Pat. No. 1,051,895, already exist. These furnaces comprise a vertical cylindrical shaft, inside which an anthracite charge is circulated continuously from top to bottom. The electric contact between the charge and the current inputs is provided by means of electrodes placed at the upper end and lower end of the furnace, generally in the axis.
During the heating treatment, the charged carbonaceous materials lose their humidity and then their volatile materials progressively, at a temperature which can range up to 1300.degree. C., and the product which is extracted from the base of the furnace is particularly suitable for the manufacture of electrodes or of blocks of various shapes made of carbon or graphite.
As mentioned in the description of the cited patent, this type of furnace has several disadvantages. Firstly, the temperature to which the charge is brought is not at all homogeneous. The fraction of the charge which is located in the vicinity of the axis of the furnce reaches sufficient temperatures to transform it into graphite and this state is not desirable for the manufacture of carbonaceous pastes. On the other hand, the fraction of the charge which is located at the periphery of the furnace is poorly heated and is frequently incompletely degassed.
In practice, if the fraction of the charge of anthracite which is poorly degassed is to be reduced to a minimum, it is necessary to overheat a significant portion of that charge. This results in an increased consumption of electric energy on the order of 1200 KWH per ton of anthracite. Moreover, the volatile materials which distill are lost.
In French Pat. No. 1,051,895 which has already been cited, it has been proposed to use the volatile materials leaving the calcination furnace to carry out preheating of the anthracite before causing it to penetrate into the furnace.
This preheating can be carried out in a rotary furnace comprising burners which are supplied by the volatile materials originating from the electric furnace or in a vertical furnace in which the granules of anthracite are lowered through a stream of hot gas originating from the combustion of the volatile materials in a separate burner.
This process, which effectively improves the overall calcination yield, requires a relatively complex installation comprising two furnaces in series which are expensive to construct and relatively awkward to operate. In particular, it is necessary to avoid having an excess of combustive in the gaseous mixture in order not to oxidize the anthracite, and this can give rise to risks of explosion which are not negligible in the presence of large quantities of hydrogen. In addition, this device does not overcome the most serious disadvantage of the electric furnace which is the lack of homogeneity in the heating of the charge.
The new furnace which is the object of the invention allows the energy consumption of electric furnaces for the calcination of carbonaceous materials which have just been described to be reduced very significantly, while making it unnecessary to combine them with complex devices for preheating the charge. It also allows the homogeneity in the temperature of the charge to be improved to a certain extent and, finally, it allows the volatile materials liberated during calcination, all or the majority of which could be used for other applications, to be recovered.
The essential characteristics of this new furnace is that it comprises, in combination, a conventional means of heating by passing a current through the charge, a means of he

REFERENCES:
patent: 1366458 (1921-01-01), Hoopes
patent: 1524784 (1925-02-01), Bartolomeis et al.
patent: 1671673 (1928-05-01), Doerschuk et al.
patent: 1975259 (1934-10-01), Derby
patent: 2710280 (1955-06-01), Borch
patent: 2757129 (1956-07-01), Reeves et al.
patent: 3464913 (1969-09-01), Berry
patent: 3705086 (1972-12-01), Schmalfedd et al.
patent: 4025610 (1977-05-01), Suzuki et al.
patent: 4251323 (1981-02-01), Smith

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