SU775556A1 - Method and rotating drum for heat treatment of loose materials - Google Patents

Description

(54) METHOD OF HEAT TREATMENT OF BULK MATERIALS

BRANCH AND DRUM FOR ITS IMPLEMENTATION The invention relates to the technology of heat treatment of bulk materials and can be used in chemical cement, metallurgical, medical and other industries. A known method of heat treatment of bulk materials, predominantly granulated potassium chloride T, by moving the material at a variable speed through the sections of a rotating drum in a strand and heat carrier l. However, the known technical solution does not allow the process of drying and heating the material before the pressing process in one drum. The aim of the invention is to intensify the process of heat and mass transfer. This goal is achieved by separating the material and heat transfer fluxes in the last section of the drum with a decrease in the thickness of the material layer and an increase in the velocity of the heat carrier above the material layer. To implement such a method, a drum can be used, containing a body divided by length into a series of sections, the last of which is made in the form of an abutment of pipes with slots symmetrically located relative to the axis of the body and interconnected by plates forming along the length of the section an adjustable gap of variable cross section for material transfer. FIG. 1 given drum, general view; in fig. 2 is a section A-A in FIG. one; in fig. 3 is a sectional view in FIG. 1. A rotating drum for carrying out the method of heating bulk materials comprises: a housing 1 divided by length into a series of sections; the last section 2 is made in the form of a set of pipes 3 with slots 4, symmetrically located relative to the axis of the housing 1 and interconnected by plates 5, forming along the length of section 2 an adjustable gap 6 of variable section for pouring material. The gap 6 can be varied with the help of hooks 7 mounted on the plates 5. The device operates as follows. Bulk material, such as granulated potassium chloride, subjected to heat treatment, and coolant — flue gases with a temperature of 600–800 ° C — are fed into the housing 1 of a rotating drum, which successively pass through sections in the flow. The field of the section in which the material is dried has a temperature of 80-120 ° C, and the heat carrier is 140-220 ° C. However, when the temperature of the material is 80-120C, it is impossible to carry out the subsequent technological operation - pressing. To intensify the process of heating the material to 130-150 ° C after the drying process in the first section, the material and the coolant are divided into separate streams, while in section 2 the thickness of the layer of material is reduced when pouring along the length of the pipes 3 and increase the speed of the coolant over the material. This ensures intensive mixing of the bulk material with the coolant, which intensifies the heating process. In this case, it is possible to increase the use of the high temperature potential of the heat transfer medium. In addition, a positive effect is achieved due to the turbulence of the gas suspension through the continuous transfer of material through adjustable gap b over the entire section of section 2.

In order to intensify the heating process, the mode of movement of the material and the coolant in section 2 is changed, which provides intensive mixing of the bulk material and its blowing in with the coolant moving through pipes 3 with higher speeds. In this case, the temperature separation of the drying agent over the cross section of the drum is excluded, the above-described arrangement of the section

2 variable profile improves mixing of the heat carrier over the cross section of Braban.

When moving the bulk material through the pipes 3 of section 2, not only the circumferential velocity increases, but also the velocity of the falling particles between the pipes 3, due to a change in the material transfer rate between the pipes

3 along their length. Variable cross section

The gaps 6 along the length of the pipe 3 and the direction of movement of the drum are determined depending on the physicochemical properties of the material being dried: moisture, flowability, etc. For example, for lumpy materials,

it is advisable to increase the channel section in the initial section of the pipe to increase and rotate the drum in the direction opposite to the placement of the gaps. In this case, the mixing process in the annular initial section of section 2 is improved, which intensifies the heat and mass transfer.

invention formula

1. The method of heat treatment of bulk materials, mainly granulated potassium chloride, by moving a material with a variable speed over sections of a rotating drum in a flow with a coolant, which is the fact that, in order to intensify the process of heat-mass transfer, in the last section of the drum flows the material and the coolant are separated with a decrease in the thickness of the layer of material and an increase in the velocity of the coolant above the layer of material.

2. A rotating drum for heat treatment of bulk materials by the method according to Claim 1, comprising a housing spaced apart in a number of sections,

5, characterized in that the last section is made as a set of pipes with slots symmetrically located relative to the axis of the housing and interconnected by plates forming along the length of the section

an adjustable gap of variable cross section for material transfer.

Sources of information taken in. attention during examination

1. USSR author's certificate No. 657222, cl. F 26 B 3/06, 1976.

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Claims (2)

Claim 1. The method of heat treatment of bulk materials, mainly granular potassium chloride, by moving the material with a variable speed in sections of a rotating drum in a direct-flow 'with a coolant, about τη and. which, in order to intensify the process of heat and mass transfer, in the last section of the drum, the flows of material and heat carrier are separated with a decrease in the thickness of the material layer and an increase in the velocity of the heat carrier over the material layer. 2. A rotating drum for heat treatment of bulk materials by the method according to claim 1, comprising a casing, loving in length for a number of sections, characterized in that the last section is made in the form of a set of pipes with slots symmetrically located relative to the axis of the casing and interconnected by plates forming along the length of the section, an adjustable gap of variable section for pouring material.