RU71157U1 - CAPERAL FURNACE FOR FIRING CERAMIC PRODUCTS - Google Patents

Abstract

The bell furnace for firing ceramic products contains a lined bell (1) with gas burners (2), a muffle fastened with it (3), guides (6) for landing the bell (1) on a fixed under (8), side hole (12) in hood (1) for smoke extraction. The muffle (3) with its lower end is buried in the sand of a gas-tight thermal shutter (9) to seal the muffle space and prevent the access of oxygen. The reducing gas medium under the hood protects the ceramic products from oxidation (burning) of carbon, and the quality of firing increases. To exit the pyrolysis gases, the muffle (3) contains a gas outlet valve (4). 1 s.p. f-ly, 1 devil.

Description

The utility model relates to heat engineering, namely to kilns for firing ceramic products.

Known bell furnaces for firing ceramic bricks, for example, RU, utility model certificate No. 939 C21D 09/161, 1995 [1], RU patent No. 2111933, C04B 33/32, F27B 11/00, 1998. [2].

The closest in combination of essential features is a bell-type furnace [2]. It consists of a lined cap with gas burners mounted on a movable under (trolley) with a substrate under the product cage, a thermal gas-tight shutter, channels in the hearth for smoke removal. Ceramic products are fired in an open flame, that is, in an oxidizing gas environment.

The main disadvantage of this furnace is the low quality of firing of ceramic products containing carbon, for example, corundum-graphite ("black" ceramics), due to the oxidation (burning) of carbon. In addition, the installation of a group of such furnaces requires significant production space and increased costs for stationary hood lifting mechanisms for each furnace, the installation of rail tracks and the creation of a furnace trolley fleet.

The objective of the utility model is to eliminate this drawback and reduce the cost of the furnace business.

The technical result is to improve the quality of firing of carbon-containing ceramic products and reduce the cost of a bell furnace.

To implement the technical result, according to the utility model, the bell furnace comprises a lined bell with gas burners, a muffle fastened with a lined bell and recessed with a lower end into a heat-tight seal, guides for landing

hood on under, side hole in the hood for smoke exhaust and stationary under.

The essence of the utility model is that the muffle protects the cage of ceramic products from direct contact with an open flame and furnace gases. The lower end of the muffle, buried in the sand of a thermal gas-tight shutter, serves as a knife that insulates the access of oxygen-containing furnace gases to the muffle space. In the absence of oxygen, a reducing gas medium is created under the muffle, which prevents the oxidation (burning) of carbon from products.

The attachment of the muffle to the lined cap allows you to remove the cap and muffle together after the end of the firing process with a lifting mechanism, for example, an overhead crane. Guides - metal racks installed around the perimeter of the fixed hearth, when lowering the lined cap enter the slotted grooves located on its outer surface, ensuring the exact fit of the cap on the hearth and sealing the internal furnace space. One lifting mechanism can serve a group of bell-type furnaces, which reduces operating costs. The fixed under, installed on the floor of the production room, and the side extraction of flue gases with the outlet to the common hog, increase the compactness of the bell furnace and do not require significant manufacturing costs. Preferably, the bell furnace has a cylindrical shape for better circulation of heat fluxes in the working space of the furnace.

In accordance with paragraph 2 of the utility model formula, the muffle contains a gas outlet valve. Through it comes the pyrolysis gas generated during the burnout of an organic binder of ceramic products and afterburned in the flame of the upper burner. The gas outlet valve is triggered by an increase in pressure under the muffle.

The utility model is illustrated by an example of a bell furnace for firing ceramic products, a general view of which is presented in the figure of the drawing.

The inventive bell furnace comprises an inside lined cap 1 with gas burners 2, a muffle 3 with a gas exhaust valve 4, fastened to the cap 1 by fasteners 5. The cap 1 with gas burners 2 and the muffle 3 is installed by raising and lowering (the lifting mechanism is not shown) along the guides 6, included in the slotted grooves 7 of the cap 1, to the fixed one under 8, mating with it the lower end of the muffle 3, buried in the sand of the heat-tight seal 9.

A cage 11 of ceramic products is installed on the substrate 10, an opening 12 is made in the lateral surface of the cap 1 to remove flue gases.

Bell furnace works as follows.

On the substrate 10 of the fixed hearth 8 set cage 11 of ceramic products. Using a lifting mechanism, lower the lined cap 1 with gas burners 2 and the muffle 3 along the guides 6 included in the slotted grooves 7 of the cap 1, to the fixed one under 8, providing sealing of the furnace with a heat-tight seal 9. In this case, the lower end of the muffle 3 is buried in thermal sand a gas tight shutter 9, sealing the muffle space where the substrate 10 with the charge 11 of ceramic products is located. Then turn on the burner 2, set the desired thermal mode. At the same time, gas burners located tangentially in the lower part of the lined cap provide circular motion of the combustion products around the muffle 3, heating it and the muffle space with a cage 11 of ceramic products, and a gas burner located in the upper part of the lined cap produces afterburning of pyrolysis gases leaving the under the muffle 3 through the gas outlet valve 4.

Under the muffle 3, a reducing medium is created, since oxygen does not get there, which prevents carbon from burning out of ceramic

products. Exhaust flue gases are removed through a hole 12 in the lateral surface of the lined cap.

As the tests showed, the proposed design changes of the bell furnace allowed to improve the quality of firing of ceramic, in particular corundum-graphite products, to prevent carbon burnout by creating a reducing gas medium under the muffle and to solve the problem.

Information sources:

1. RU, utility model certificate No. 939 C21D 09/161, 1995 [1];

2. RU, patent No. 2111933, С04В 33/32, F27B 11/00, 1998. [2].

Claims (2)

1. A bell furnace for firing ceramic products, comprising a lined hood with gas burners mounted on a beneath a substrate, a thermal gas tight shutter, smoke exhaust ducts, characterized in that the furnace further comprises a muffle fastened with a hood and recessed with a lower end into a thermal gas tight shutter , guides for planting the hood on under, the side hole in the hood for smoke exhaust, and under the fixed. 2. A bell furnace according to claim 1, characterized in that the muffle comprises a gas outlet valve.