SU1502937A1 - Cyclone furnace for manufacturing powder lime - Google Patents

Abstract

The invention relates to the building materials industry and makes it possible to improve the quality of the product obtained. The cyclone furnace contains a cylindrical body with gas-burning devices, a lower flue gas and material outlet and a central loading through a nozzle, made in the form of a diffuser with an angle of α = ARCTG [(0.3-0.6) R / L], where R is the radius furnaces, L is the distance from the loading plane to the first plane along the burner gas. At the exit of the diffuser installed twisting blades. 1 il.

Description

The invention relates to the field of heat treatment of finely ground powdered materials and can be used to produce lime in the metallurgical industry and the construction materials industry.

The purpose of the invention is to improve the quality of the product.

The drawing shows a cycling furnace, a general view.

The cyclone furnace consists of a cylindrical body 1, lined from the inside with a refractory brick. In case 1, a gas-burning device 2 for supplying a gaseous heat carrier is installed in the case 1, a branch pipe 3 for the central loading of material, made in the shape of an UEor foil with a guide 4 on the outlet. The distance from the material loading plane to the furnace to the plane of the first gas-burning device along the gas flow movement is 1. The flue gases and material are removed from the furnace through pipe 5.

The furnace works as follows. When starting the furnace through gas-burning devices 2 into the working space bounded by the lined cylindrical body 1, the flow of heat-transfer fluid — the gas-air mixture — is injected tangentially, where it burns out with the release of heat. Through the pipe 3 serves air. After the heating of the furnace, it is brought to the operating mode: the required flow rate of the heat transfer fluid is set through the gas-burning devices 2 and into the stream in the spirit;

about to

 with

The material that is heat-treated is introduced into the nozzle-diffuser 3, the material is known. Passing through the diffuser 3 with the directional apparatus 4 in the form of twisting blades, the material is spilled and evenly distributed in the heat-transfer stream, which contributes to its high-quality roasting. This is achieved at a certain opening angle of the diffuser 3, the value of which is determined by the dependence

g R

 2 arctg (0.3-0.6) -g-I After heat treatment in the furnace, the lime material together with the flue gases is removed through the nozzle 5 and the final product trapping system, for which various kinds of cyclone precipitators and an electrostatic precipitator can be used gas cleaning.

Example. The cyclone kiln's pre-construction was tested when roasting ground limestone containing 92% class minus 71 microns. The composition of limestone,%: CaO 52,12; MgO 2.5, SiO 1.68%; ppt AZ, 68; 0.02. The consumption of lime is 1.5-2 t / h, the specific fuel consumption corresponds to 90-95 lime, natural gas with a calorific value of 8500 kcal / m is used as a fuel. The material is loaded into the furnace in an air flow (air flow rate for pneumatic transport is 400–500 m / h) through a nozzle, made in the form of a diffuser with a guiding device — swirling blades. The opening angle of the diffuser is defined as a function of AC f (R, l), the internal radius of the furnace R is 0.8 m, and the distance from the plane of the material input into the furnace to the plane of the first in the direction of the gas flow of the input of the coolant through the gas burner device 1 is 0.4 and 0.8 m. At the same time, diffusers with different angles open (about 25 to 120 °). During the tests, it was established that at the opening angle of the diffuser,

expression o6 2 arctg (0.3-0.6) y and supplied with a directional apparatus

in the form of twisting blades, a uniform distribution of the material in the flow of the heat carrier is achieved and lime is obtained with the following

0

five

0

the quality standards: (CaO – MgO) ort 90, A – 93.1%, (CaO + MgO) 84.5– 88.4%, hydrate 1D1 and lime 0.75– 1.0 min.

When the opening angle of the diffuser is less than its optimum value, in particular when 2 arctg f (0.111R 7

0,289) -I, lime is obtained with the following composition: (CaO + MgO) AE, 69.7- 81.5%, (CaO + MgOaKT 57.9 - 69.4%, the hydration time is 1.5-2.0 minutes. These the rates are lower than in the first case due to the movement of the material in the paraxial region and the material is in the burning zone for a time less than optimal.

When the opening angle of the diffuser is greater than its optimum value, in particular when ac 2 arctg {(0.637 R 1 - 1.0) YJ, the formation of

brick wall and lime contain: (CaO + MgO) oBH 90-92%; (CaO + + MgO) Q, (f 56,4–62.6%, lime hydration time 5.5–8.0 min. Relatively low content of active calcium and magnesium oxides in lime and long hydration time indicate lime burnout in ovens.

These data were obtained when the guide vane was installed in the form of twisting blades at the exit of the diffuser. Without a guide apparatus, lime quality indicators in all cases are 2.5-6.4% lower.

Claims (1)

Invention Formula A cyclone kiln for the production of powdered lime, containing a cylindrical body with gas-burning devices, central loading and lower flue gas and material outlet, characterized in that with the increase in the quality of the product obtained, the central loading pipe is made in the form of a diffuser with an angle of determined by dependency about (2 arctg (0.3-0.6) Y, where dC is the angle of the diffuser, rad, R is the internal radius of the furnace, m; 1 is the distance from the material loading plane to the furnace along 15029376 the plane of the first one along the way and is equipped with a guide apparatus installed at the outlet of the movement of the gas flow of a gas from the diffuser of the burner device, m, in the form of twisting blades.