SU1190167A1 - Rotating furnace with heat exchange lining for alumina calcination - Google Patents

Abstract

A ROTATING OVEN WITH HEAT-EXCHANGE LIGHTING FOR CALCINATION OF ALUMINUM, containing in the dehydration zone a lining in the form of a multiple-entry screw, reverse to the inclination and rotation of the furnace, with a lifting angle equal to or greater than the angle of natural slope of the material being burned, it is different. that, in order to control heat exchange, increase kiln performance and reduce fuel consumption, the initial lining section of the lining is made with a slit surface formed by narrow gaps between refractory bricks lining each second longitudinal axis of the kiln, which are not filled with binder solution.

Description

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FIG. one

The invention relates to heat engineering and can be used for lining rotary kilns used in alumina cement and other industries.

The purpose of the invention is to increase heat transfer, increase furnace productivity and reduce fuel consumption.

A rotary kiln with a heat exchange lining for calcining alumina contains in the dehydration zone a lining in the form of a multiple-pass screw, reverse to the slope and rotation of the furnace and with a lifting angle equal to or greater than the angle of repose of the material to be baked, the initial lining section is made with a slit surface formed by narrow gaps between the refractory bricks of the lining of each second longitudinal axis of the kiln, which are not filled with binder solution.

FIG. 1 shows a furnace, a longitudinal section; in fig. 2 and 3 tribute to the options for laying the lining of refractory bricks of two sizes.

The furnace is a steel cylinder 1 containing a dehydration zone, lined from the inside with refractory bricks 2. The lining in the dehydration zone is divided into two sections 3 and 4, and in the first section along the movement of gases 3 it is made with gaps 5 between the bricks of every second p yes the longitudinal axis of the furnace.

Furnace with heat exchange lining works as follows.

The material entering the slit-lined section 3 fills the slots 5 and, together with the turning of the furnace, rises upwards, after which it begins to pour out of them gradually, creating a curtain of fine powder sprayed in gases. The material scattered in thin streams exposes its surface as much as possible when entering into akU

heat exchange with cross-flow gases. Due to the presence in the furnace of the wind from moving towards the material flow of gases, the suspended particles of the material are thrown a few meters back, creating a barrier to the movement of the layer to the discharge end.

This increases the filling of the cross section with the furnace material and its residence time in the dehydration zone, which has a positive effect on the increase in heat transfer, an increase in the productivity of the furnace and a decrease in fuel consumption. In order to prevent material from being carried back into the area of the substance, the length of section 3 is determined by the formula

Wed

1-d-f- З.A. -hn

St

the length of the section with a slit lining; the length of the dehydration zone;

drop height of particles from the slots; gas velocity in the dehydration zone; average rate of incidence of particles.

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Claims (1)

ROTARY FURNACE WITH HEAT EXCHANGE LINING FOR ALUMINUM CALCINATION, containing in the dehydration zone a lining in the form of a multi-start screw, reverse to the slope and rotation of the furnace, with a lift angle equal to or greater than the angle of repose of the calcined material, characterized in that. that, in order to increase heat exchange, increase furnace productivity, and reduce fuel consumption, the lining portion that is initial in the direction of gas movement is made with a slit surface formed by narrow gaps between the refractory bricks of the lining of each second longitudinal axis of the row furnace that are not filled with a binder solution.