RU2074842C1 - Method and plant for manufacturing building materials utilizing fuel-containing wastes - Google Patents

Abstract

FIELD: manufacture of building materials. SUBSTANCE: fuel-containing waste is crushed and supplemented with additives converting it into a blend suitable to produce desirable building material. Blend is melted in a cyclone melting unit wherein temperature is controlled with additionally installed fuel burners. Melting unit is installed as burner means in baking furnace wherein off-gas heat is utilized to dry and bake additional amount of raw material. Air introduced into melting unit is preheated with baking furnace off-gases in a heat exchanger installed after baking furnace. EFFECT: completely utilized heat value of waste and achieved stable operating condition. 10 cl, 1 dwg

Description

 The field of use is ecology, heat power engineering, construction industry, namely, the production of building materials using fuel-containing waste.

 Ashes of thermal power plants (TPPs), associated rocks from coal mining and waste from central coal processing plants (COF) are currently large-tonnage waste from the energy and coal industries. The use of these wastes is very limited, mainly due to the high content of residual fuel in them (from 2-3 to 30-40%), which can vary during the day and even hours of operation of thermal power plants and central processing plants.

 A known method and device for producing a porous aggregate, which consists in the fact that fuel-containing ash and air heated by the heat of the exhaust gases are supplied to the cyclone melting unit, the temperature in the cyclone melting unit is regulated by burners installed in it, the exhaust gases of the cyclone melting unit are sent to the kiln furnace, into a heat exchanger for heating air and into a rotating drum for drying ash sludge. The ash melt is cooled, dried, ground, granulated and calcined in a kiln to obtain a porous aggregate.

 A device for producing a porous aggregate consists of a cyclone melting unit connected by a gas duct to a countercurrent rotary heater and a kiln. The device also includes a heat exchanger for heating the air with exhaust gases. The high-temperature gas in this device is used for three purposes: heating air in a heat exchanger, drying the material in a rotating heater, and firing the material in a kiln (1).

The disadvantage of the device and method is the difficulty of quantitative and temperature distribution of the gas stream leaving the cyclone in the heater, heat exchanger and kiln due to the different aerodynamic drag of these units. Use of regulating elements of dampers, gates, etc. for the distribution of high temperature gas (1500-1600 ^o C) is difficult, and as a result, the operation of the device becomes unstable.

 Closest to the proposed method and device are a method and device for the production of cement and lime based on fuel-containing waste (2).

 The method consists in the fact that the fuel-containing waste is melted in the melting cyclone together with corrective additives, the raw materials are dried and fired in the kiln, and the air supplied to the melting cyclone is heated by the exhaust gases of the kiln.

 The device includes a melting cyclone connected to the kiln, and a heat exchanger installed at the exhaust gas outlet of the kiln, connected by a duct to the melting cyclone.

 The disadvantage of this device is the complex technological scheme, which makes it difficult to control a variety of technological processes, and non-standard equipment necessary for its implementation.

 A common disadvantage of the known solutions is that the heat received as a result of the combustion of fuel is not fully used. Known solutions do not allow the processing of waste containing a variable amount of fuel, and do not ensure the stable operation of technological units.

 Thus, the objective of the present invention is the processing of fuel-containing waste with a variable fuel content, obtaining due to its calorific value the maximum amount of building materials and the stability of the technological mode of processing.

 The problem is solved in such a way that in the method for the production of building materials using fuel-containing waste, which consists in the fact that the fuel-containing waste is melted in a melting cyclone together with corrective additives, the non-containing fuel is dried and fired in the kiln, and the waste gases of the kiln are heated air supplied to the melting cyclone, pre-fuel-containing waste is crushed, the temperature in the melting cyclone is maintained by the mount installed in it lkami, and firing of raw materials in the kiln is carried out due to the heat of the exhaust gases of the melting cyclone.

 In addition, additives that adjust the mineral composition to the composition of glandular, belite or alite clinker or slag granulate are introduced into the fuel-containing waste. In the kiln, an eye is carried out and carbonate raw materials are fired to produce lime, fired iron, belite or alite clinker, and porous aggregate or ceramic products are dried and fired. The temperature regime for firing raw materials with exhaust gases in a kiln is controlled by mixing the exhaust gases with the surrounding air due to the vacuum created by the suction devices.

 In the device for the production of building materials using fuel-containing waste, including a melting unit cyclone connected to the kiln and installed at the outlet of the exhaust gases of the kiln, a heat exchanger connected by a duct to the melting cyclone, the latter is installed as a burner device of the kiln, and additionally installed on the melting cyclone burner devices. As a kiln, a rotary, shaft or tunnel kiln is installed. The kiln contains a refrigerator or a drying unit.

 The invention is illustrated in the drawing, which shows a device for the production of building materials.

 The device comprises a cyclone melting unit 1 with fuel burners 2. The melting cyclone unit 1 is installed as a burner of the kiln 3, behind the kiln 3 there is a heat exchanger 4 for heating the exhaust gas gases.

 The device operates as follows.

 The dried and filtered fuel-containing waste is fed to the cyclone melting unit 1. The melting temperature is achieved by burning the fuel component of the waste and is regulated by the additional supply of liquid or gaseous fuel by burners 2, the exhaust gases from the melting unit 1 are directly sent to the kiln 3, in which the cement is fired. clinker, lime, porous aggregates or other building materials. The firing temperature in the kiln is regulated by mixing the exhaust gases with the surrounding air (adjustable suction) due to the vacuum created by the suction devices. The air supplied to the cyclone melting unit 1 is heated by the exhaust gases of the kiln in a heat exchanger 4, which are then used for low-temperature roasting or drying of materials.

 Examples of the method.

 Example 1

 Obtaining melted clinker in a cyclone melting unit and fired cement clinker in a rotary kiln, interlocked with the melting unit.

As raw materials, calcium fly ash of the Nazarovskaya TPP of the Kansk-Achinsk coal basin, as well as corrective additives limestone and pyrite cinder, with the calculation of clinkers with a saturation coefficient from 0.7 (ferruginous clinker) to 0.9 (alite clinker), were used as raw materials silicate module from 1.0 to 3.0 and an alumina module value from 1.0 to 2.5. The component mixtures were ground to a specific surface of 500 m ² / kg. At the same time, mixtures of ferrous and belitic composition were fed into a cyclone melting unit, and a raw mixture of alitic composition was sent to a kiln (rotary kiln). In a cyclone melting unit, the raw material mixtures melted at a temperature of 1350-1450 ^o C, and in a rotary kiln, alite clinkers were fired before sintering at a temperature range of 1450-1470 ^o C. The exhaust gas temperature of the cyclone melting unit, which acts as a burner for a rotary kiln, was regulated in the range of 1550-1650 ^o C. the fuel Consumption for obtaining fused clinkers ranged from 60 to 80% of the fuel consumption for obtaining the same clinkers from natural raw materials. Fuel economy is achieved due to the presence of residual fuel and decarbonized calcium component in the ash. Fired alite clinker was obtained with zero additional fuel consumption, i.e. due to the heat of the exhaust gases from the cyclone.

 Example 2

 Obtaining fused cement clinker and lime.

 As a raw material component for clinker use, fly ash of TPP-22, operating on coals of the Kuznetsk and Donetsk coal basins, and corrective additives of limestone and pyrite cinder were used. Limestone of the Venevsky deposit served as carbonate raw material for lime production. The preparation of the raw mix and the firing of fused clinker were carried out as in example 1.

 Limestone was fed into a rotary kiln with fractions of 10–40 mm (a departure from lime production in shaft kilns). The temperature of the exhaust gases used for calcining limestone in a rotary kiln was controlled by suction of ambient cold air through the kiln coolers.

 Example 3

 Production of granulate (concrete aggregate, ceramics slurry, semi-finished product for the manufacture of especially lightweight porous aggregate) and lime.

To obtain granulate in a cyclone smelting unit, coal beneficiation waste from the Kuznetsk coal basin (Siberian coal processing plant) with a residual fuel content of 36% with the addition of 8% limestone was used. The raw material mixture was dried, crushed to a specific surface of 100-150 m ² / kg and fed into a cyclone unit. The mixture was melted at a temperature of 1350-1450 ^o C and upon exiting the piggy bank by rapid cooling by water or air-water methods turned into granulate. The exhaust gases from the cyclone were used to produce lime in a shaft furnace. The fuel consumption for producing granulate due to the high residual fuel content in the waste was 20-30% compared to the production of granulate from natural raw materials. For lime burning, as in examples 1, 2, additional fuel is not required.

The proposed method and device give the following technical result:
Depending on the composition of the fuel-containing waste, it is possible to produce various semi-finished products and finished building materials of ferruginous, whiteite, and alite clinker in a cyclone smelting unit for the manufacture of various types of cement, dense aggregate of concrete, a filler for ceramic production, granulate for the subsequent production of especially lightweight porous aggregates, etc.

in the cyclone unit connected to the kiln, it is possible to produce the same material (for example, fused and calcined clinker), or various building materials;
the calorific value of the fuel-containing waste is used with density, because the heat of the exhaust gases from the cyclone is effectively used according to well-known, multiple proven technologies;
the possibility of using waste with a variable fuel content and obtaining due to its calorific value the maximum amount of the product is achieved;
it is possible to produce, due to the calorific value of fuel-containing waste, high-temperature firing processes of building materials, for example, cement clinker;
stability of the operating mode is achieved due to the simultaneous regulation of the temperature in the melting cyclone by fuel burners and the temperature in the kiln by suction of ambient air, as well as by directing the entire flow of exhaust gases of the cyclone melting unit directly to the kiln.

Claims (10)

 1. A method for the production of building materials using fuel-containing waste, which consists in the fact that the fuel-containing waste is melted in a melting cyclone together with corrective additives, the raw materials are dried and fired in the kiln, and the air supplied to the melting cyclone is heated by the exhaust gases of the kiln , characterized in that the pre-fuel-containing waste is crushed, the temperature in the melting cyclone is supported by the burners installed in it, and the firing of raw materials in firing howling furnace is carried out by the heat of exhaust gas of the melting cyclone.  2. The method according to claim 1, characterized in that additives are added to the fuel-containing waste, correcting the mineral composition to the composition of glandular, belite or alite clinker or slag granulate.  3. The method according to claim 1, characterized in that in the kiln, drying and calcining of carbonate raw materials to produce lime.  4. The method according to claim 1, characterized in that in the kiln annealing fired glandular white or alite clinker.  5. The method according to claim 1, characterized in that in the kiln, the porous aggregate or ceramic products are dried and fired.  6. The method according to claim 1, characterized in that the temperature regime of firing the raw material with exhaust gases in a kiln is controlled by mixing the exhaust gases with the surrounding air due to the vacuum created by the suction devices.  7. A device for the production of building materials using fuel-containing waste, including a melting cyclone connected to the kiln and installed at the outlet of the exhaust gases of the kiln, a heat exchanger connected by a duct to the melting cyclone, characterized in that the melting cyclone is installed as a burner device of the kiln, and burner devices are additionally installed on the melting cyclone.  8. The device according to claim 7, characterized in that a rotary, shaft or tunnel furnace is installed as the kiln.  9. The device according to claim 7, characterized in that the kiln contains a refrigerator.  10. The device according to p. 7, characterized in that the kiln contains a drying unit.