RU2164329C2 - Method of production of powder-like products - Google Patents

Abstract

FIELD: manufacture of building materials, lime in particular; metallurgy; food-processing industry (manufacture of sugar) and other industries. SUBSTANCE: method includes tangential delivery of raw material, air and fuel to roasting furnace, roasting of raw material, removal of finished product and waste gases from roasting furnace and separation of finished product. Raw material, air and fuel are delivered at the bottom of roasting furnace; raw material and air are heated preliminarily. Roasting is effected in two-phase ascending flow. Separation of finished product is performed without preliminary cooling; waste gases are exhausted from upper portion of furnace; preliminary heating of raw material and air is effected through recuperation in parallel flow of phases by heat of waste gases and finished product, respectively. EFFECT: reduced consumption of fuel due to recuperation of heat of waste gases and high-temperature finished product. 1 dwg

Description

 The invention relates to the production of building materials, in particular to the production of lime, and can be used in the building materials industry, in the metallurgical industry, in the food industry (in the production of sugar) and in other sectors of the national economy.

 A known method of producing a powdery product, including the supply of raw materials and fuel to the kiln, firing of raw materials, separation of the finished product and dust removal of exhaust gases, implemented in a device for the production of powdered lime (see A. S. USSR N 1502937, MKI F 27 B 7 / 20, dated May 30, 1989) - an analogue.

 The disadvantage of this method is the high cost of its implementation (requires the presence of electrostatic precipitators, powerful smoke exhausters, and this leads to high energy costs).

 The closest in technical essence and the achieved effect to the proposed solution is a method for producing powdered products, including the supply of fuel and preheated raw materials and air to the kiln, firing of raw materials, removal of the finished product and exhaust gases from the top of the furnace and separation of the finished product, while the supply of fuel and preheated air is carried out from below the kiln, the firing is carried out in a two-phase flow, the separation of the finished product is carried out without preliminary cooling I, preheating feedstock and produce air flow in phase regeneratively heat the exhaust gases and the finished product, respectively, and heating the raw materials is carried out in cocurrent phase (see GB 1,302,417 A, B 27 Cl 15 F / 00,10.01.1973..) - prototype.

 A disadvantage of the known solution is unreasonably large fuel consumption, due to the fact that in the known method, the recovery of the heat of the exhaust gases and the finished product is not efficient enough.

 The objective of the invention is to reduce fuel consumption in the production of powdered products by increasing the recovery of heat of exhaust gases and high-temperature finished product for heating raw materials and air.

 To achieve the task in a known method, including the supply of fuel and preheated raw materials and air to the kiln, firing of raw materials, the removal of the finished product and exhaust gases from the upper part of the furnace and the separation of the finished product, and the supply of fuel and preheated air is carried out from the bottom of the kiln , firing is carried out in a two-phase flow, the separation of the finished product is carried out without preliminary cooling, preliminary heating of the raw materials and air is performed regeneratively in the phase flow with heat o flue gases and the finished product, respectively, while heating the raw materials is carried out in direct flow phases; the supply of fuel, raw materials and air to the furnace is carried out from below the furnace, the raw materials are fired in an upward flow, and air heating by the heat of the finished product is carried out in direct flow.

 Comparative analysis with the prototype shows that the inventive method for producing a powdery product differs from the known one in that the supply of fuel, raw materials and air is carried out from the bottom of the furnace, the raw materials are fired in an upward flow, and air heating by heat of the finished product is carried out in direct flow.

 Therefore, the proposed solution meets the criterion of "novelty."

 The conducted patent studies allow us to conclude that the proposed method corresponds to an inventive step, since there are no solutions with similar features in the patent literature.

 The tangential supply of fuel, raw materials and air to the furnace and firing of raw materials in the upward flow allow to increase the residence time of the particles of raw materials in high-temperature exhaust gases due to overcoming the force of gravity, which positively affects the quality of the product. Heated air with the heat of the finished product in the direct flow allows to improve the gas-dynamic characteristics of the kiln by reducing the resistance of gas flows and improving heat and mass transfer.

 The essence of the invention is to create optimal operating conditions for technological equipment and use the heat of a high-temperature product and exhaust hot gases to preheat raw materials and air (fuel, raw materials and air are supplied to the furnace tangentially, the raw materials are supplied from the bottom of the furnace, the raw materials are fired in an upward flow, and heating the air with the heat of the finished product is carried out in direct flow).

 A device for implementing the proposed method is shown in the drawing.

 It consists of a kiln - I (see drawing), an air heater - II and a raw material heater - III. The kiln I consists of a kiln 1, which is equipped with tangential nozzles 2 and 3 for supplying combustible and heated air, respectively, and a pipe 4 for supplying heated raw materials. The kiln 1 through the pipe 5 is in communication with the separator 6 of the high-temperature product (a conventional vortex apparatus of general industrial production, see BS Sazhin "Fundamentals of drying technology." - M .: Chemistry, 1984, p. 219, Fig. 6.22). The pipe 7 of the separator 6 is designed for the removal of high-temperature finished product, and the pipe 8 for the removal of high-temperature exhaust gases; the separator 6 has a hopper 9 of the finished product. In the hopper 9 is injected atmospheric air with a fan 10.

 The air heater II is made in the form of a separator 11 (a conventional vortex apparatus of general industrial production, see BS Sazhin, "Fundamentals of Drying Techniques." - M .: Chemistry, 1984, p. 219, Fig. 6.22.), In which separation occurs finished chilled product and heated air. The separator 11 is equipped with nozzles 12 for supplying a low-temperature product, a nozzle 13 in communication with the hopper 14 of the cooled finished product, the outlet 15 of the separator is in communication with the nozzle 3 for supplying heated air to the kiln 1.

 The raw material heater III is made in the form of a separator 16 (a conventional vortex apparatus of general industrial production, see BS Sazhin, “Fundamentals of Drying Techniques.” - M.: Chemistry, 1984, p. 219, Fig. 6.22.) With a bunker 17 of cold raw materials and nozzles 18 of the inlet to the separator 16. The hopper 17 is equipped with a nozzle 19 of the outlet from the hopper of cold raw materials. The output 8 of the separator 5 is connected with the output of the hopper 17 by the pipe 19. The output 19 of the hopper 17 is connected with the input 18 of the separator 16. The output 20 of the separator 16 is connected to the pipe 4 for supplying heated raw material to the kiln 1. The output 21 of the separator 16 is communicated through a smoke exhauster 22 and a chimney 23 with the atmosphere.

 The device operates as follows: through nozzle 2, fuel is supplied, and through nozzle 3, air preheated in air heater II, into the furnace of the kiln 1. After the kiln enters the set mode, the heated raw material is fed through the nozzle 4 (in the raw material heater III ) to the kiln 1. In the kiln, decarbonization of the feed occurs in the upward stream. The high-temperature gas-solid mixture enters through the inlet 5 to the separator 6, where the separation of the high-temperature product and high-temperature exhaust gases occurs. Through the outlet 7 of the separator 6, the high-temperature product enters the hopper 9 and mixes with the cold atmospheric air pumped by the fan 10. The cold atmospheric air is heated by the heat of the high-temperature product. This mixture enters through the inlet 12 to the separator 11, where the finished product, which gave its heat to the air in the direct-flow phases, is stored in the hopper 14, and the air heated by the heat of the finished product from the separator 11, through the outlet 15 and the nozzle 3 is fed to the burning kiln 1.

 High-temperature exhaust gases through the outlet 8 of the separator 6, capturing cold raw materials from the pipe 19 of the hopper 17, are fed to the input 18 of the separator 16, the raw materials are heated regeneratively in the direct flow of phases by the heat of the exhaust gases. Heated raw materials through the outlet 20 of the separator 16 and the pipe 4 enters the kiln 1. After that, the cycle repeats. Cooled and purified exhaust gases that gave their heat to the raw materials through the outlet 21 of the separator 16, the exhaust fan 22 and the chimney 23 are released into the atmosphere.

 The proposed method for producing powdered products in comparison with the prototype allows to reduce fuel and energy costs by half, to exclude an expensive, energy-intensive and difficult to operate electrostatic precipitator from technological equipment, and to prevent overgrowth of the lower roof of the furnace by raw materials.

Claims (1)

 A method for producing powdered products, including the supply of fuel and preheated raw materials and air to the kiln, the burning of raw materials, the removal of the finished product and exhaust gases from the upper part of the kiln and the separation of the finished product, moreover, the supply of combustible and preheated air is carried out from below the kiln, firing is performed in a two-phase stream, the separation of the finished product is carried out without preliminary cooling, preliminary heating of the raw materials and air is carried out regeneratively in the phase stream with the heat of the outgoing ha call and the finished product, respectively, while heating the raw materials is carried out in direct flow phases, characterized in that the supply of fuel, raw materials and air to the furnace is produced tangentially, the supply of raw materials is carried out from the bottom of the furnace, the raw materials are fired in an upward flow, and the air is heated by heat of the finished product in direct flow.