RU2182233C1 - Waste briquetting method - Google Patents

Abstract

FIELD: fuel energy complex. SUBSTANCE: invention relates to waste processing in installations using exhaust gases. Proposed method includes grinding of waste, treatment of waste with heat carrier and subsequent pressing. After grinding, waste materials are wetted to humidity of 5 to 50 mass % with water, and steam-gas mixture containing steam and products of thermal decomposition of waste materials, mass ratio (1-20):1 is used as heat carrier. Steam-gas mixture used as heat carrier is obtained by evaporation of moisture from waste material and thermal decomposition of material at temperature of 180-320 C and pressure of 1 to 10 kgt/cm². EFFECT: reduced energy consumption and amount of harmful effluents into surrounding medium. 2 cl, 1 dwg, 2 ex

Description

 The invention relates to the technology of waste treatment in installations using exhaust gases and can be used in the fuel and energy complex.

A known installation in which wood waste is crushed to particle sizes (0.04 - 10.9) • 10 ^-3 m, treated with superheated water vapor at a temperature of up to 300 ^o C in the filtration mode and pressed. For processing using superheated steam with a temperature of 100-300 ^o With a filtering speed through the waste layer of 2.48 m / s (RF patent 2046821, 1995).

The disadvantages of this method are:
- the high energy intensity of the process, caused by the need for energy for the production of superheated water vapor, as well as the fact that only the heat of superheating of the steam is used in the processing, and the heat of evaporation (more than 80% of the energy cost of producing superheated steam) is not used;
- high consumption of water vapor due to the high (2.48 m / s) speed of filtering it through the waste layer;
- the formation of large quantities of liquid products that must be cleaned before returning to the steam generator to produce steam;
- the presence of a special system for overheating water vapor up to 300 ^o C, which complicates the equipment for producing fuel briquettes by this method.

 The objective of the invention is to reduce energy intensity and reduce the amount of emissions into the environment.

The problem is solved in that after grinding, the waste is moistened to a moisture content of 5 ÷ 50 wt.% By supplying water, and as a heat carrier, a gas-vapor mixture containing water vapor and thermal decomposition products of the waste in a mass ratio (1 ÷ 20): 1, which obtained by evaporation of moisture from waste and thermal decomposition of the latter at a temperature of 180-320 ^o C and a pressure of 1 ÷ 10 kgf / cm ² .

 In addition, it is new that condensate is used in the amount of (0.053 ÷ 1.0) kg per kilogram of waste to moisten the waste, which is obtained by condensation of the spent steam-gas mixture.

 The drawing shows a combined-cycle plant for implementing the proposed method.

 The installation comprises a waste chopper 1 connected by non-transport to a storage hopper 2, in which a moisture meter 3, a condensate tank 4, a water flow meter 5, a crane 6, a screw 7 installed in the storage hopper 2 are installed, a dispenser for supplying waste 8 to the heat treatment chamber 9, a furnace 10, a jacket 11 of a chamber 9, a smoke exhauster 12 connected to a chimney 13, an engine 14 connected to an auger 15, a temperature sensor 16 and a gas analyzer 17 installed in the chamber 9, a dispenser 18 for supplying waste to the press 19, a roller table 20 , pressure gauge-regulator 21 and executive mech ISM 22, a valve 23 for regulating the supply of the gas mixture to the condenser 24, a fan 25, a valve 26, a valve 27 for supplying the gas mixture in the furnace 10.

 Installation works as follows.

 In the grinder 1 serves wood waste and grind them. In addition, biomass waste such as straw, husks of sunflower seeds, ears of corn, rice husks, etc. can be recycled. The pulverized waste is then transported to the storage bin 2 by pneumatic transport, where the moisture content of the waste is measured using a moisture meter. From the tank 4 through the flow meter 5 and the crane 6 in the hopper 2 serves water (condensate). Using the screw 7, the waste is mixed to achieve uniform moisture and then fed through the dispenser 8 into the chamber 9.

 At the same time, dry wood waste is burned in the furnace 10 and the combustion products are fed into the jacket 11, and then with the help of a smoke exhauster 12, the combustion products are discharged into the chimney 13. At the same time as the waste is fed into the chamber 9, the screw 15 is rotated by the engine 14, which transfers the waste from the entrance to the chamber 9 to the exit from it. The temperature in the chamber is monitored by the readings of the temperature sensor 16, and the composition of the vapor-gas mixture is monitored by the readings of the gas analyzer 17.

 To ensure a given composition of the gas-vapor mixture and the temperature at the outlet of the chamber, the number of revolutions of the screw is controlled and the amount of combustion products pumped through the jacket 11 is changed by means of a smoke exhaust fan 12. When the content of decomposition products in the gas-vapor mixture decreases (the amount of water vapor increases, as shown by device 17), the number of revolutions of the screw, which increases the residence time of the waste in the chamber, and increase the consumption of combustion products through the jacket of the heat chamber.

 Upon reaching the specified parameters (temperature and composition of the vapor-gas mixture) using the dispenser 18, the treated waste is removed to the press 19 and pressed into briquettes, which are sent to the warehouse along the rolling table 20. The mixture formed in the chamber creates a pressure, the value of which is monitored by the pressure gauge-regulator 21. When the pressure in the chamber 9 is exceeded, through the valve 22 and the valve 23, the mixture is partially supplied to the condenser 24, where it is condensed by cooling with air supplied by the fan 25. Part of the mixture and non-condensable gases through the valve 22, the valves 26 and 27 are fed into the furnace 10 and burned.

 When treating waste with superheated water vapor, only the heat of superheating of the steam, which is spent on heating the waste, evaporating the moisture of the waste, overheating the water vapor generated from the moisture, and thermal decomposition of the wood, is useful.

где С_р ^п = 2 кДж/кг^oС - удельная теплоемкость водяного пара;
Т_пер. = (Т_пара - 100^oС) - величина перегрева пара;
С_р ^в= 4,18 кДж/кг^oС - удельная теплоемкость воды;
ΔT_нагр = 100^°C; R_ф=2257 кДж/кг - теплота испарения воды.The ratio of the heat of superheating of the steam to the heat spent to obtain it is (see Theoretical Foundations of Heat Engineering. Thermotechnical Experiment: Handbook / Edited by V.A. Grigoriev, V.M. Zorin - 2nd ed., Revised M .: Energoatomizdat, 1988, p. 211, book 2, table 3.15; p. 127, table 2.10)

where C _p ^p = 2 kJ / kg ^o C is the specific heat of water vapor;
T _lane = (T _steam - 100 ^o C) - the value of steam overheating;
With _p ⁱⁿ = 4.18 kJ / kg ^o With - the specific heat of water;
ΔT _heat = 100 ^° C; R _f = 2257 kJ / kg is the heat of evaporation of water.

From (1) it follows that the magnitude of the heat of overheating can be comparable with the cost of heat for the production of steam only with significant overheating. For example, the heat of overheating is equal to the heat spent on steam, at T _per. = 1337 ^o C. When using superheated steam with T = 1437 ^o C (T _lane = 1337 ^o C) for the treatment of wood waste, a coefficient of efficiency representing the ratio of the heat of superheating of the steam to the total amount of heat spent on receiving and superheating the steam is not will exceed 50%.

At the same time, to obtain steam with a high temperature (Т = 1000 ^o С), special equipment from heat-resistant materials is required, and the use of such steam as a coolant can lead to overheating and gasification, i.e., the conversion of part of wood into gas as a result of reactions the interaction of water vapor with charred wood, which will entail a decrease in the strength of briquettes during subsequent pressing and emission of harmful gases (CO gas is contained in gasification gases) into the atmosphere.

 The use of a vapor-gas mixture as a heat carrier instead of superheated water vapor, obtained by evaporating moisture from waste and thermal decomposition of the latter, reduces energy costs for the treatment process, reduces steam consumption and reduces the amount of harmful emissions into the environment.

 This is due to the fact that the coolant for waste treatment is obtained not in the steam generator, but in the waste mass, as a result of which moisture is removed from the waste and superheated water vapor is generated. In this case, the heat spent on heating and evaporating water (moisture from the waste) is used beneficially. At the same time, the consumption of superheated water vapor also decreases due to the use of steam generated from the waste moisture. Thus, for the treatment of waste, not only the heat of superheating of the steam is used, but also the heat of heating and evaporation of water, since the own moisture of the waste is heated and evaporated. The value of the beneficial use of heat (efficiency) supplied to the waste in this case is determined only by the amount of heat loss during processing and can reach (with good thermal insulation) 80-85%.

 Since heat loss depends not only on the quality of thermal insulation, but also on the temperature level of the process (heat loss decreases with decreasing process temperature), to increase the efficiency it is necessary to lower the processing temperature, and hence the temperature of the coolant. Lowering the temperature of waste treatment leads to a decrease in the amount of gaseous products resulting from treatment, which leads to a reduction in harmful emissions into the environment.

 The use of a gas-vapor mixture as a heat carrier (superheated water vapor and thermal decomposition products of wood) leads to an increase in the intensity of heat transfer processes and an acceleration of waste heating, which means a reduction in processing time, a heat carrier consumption and, as a consequence, a reduction in energy consumption.

 The intensification of heat transfer from the coolant to the wood waste is ensured by the fact that the gas-vapor mixture has a higher density compared to superheated water vapor.

 It is known that the density of superheated water vapor decreases with increasing temperature (see table).

 To increase the density of the coolant, it is necessary to add gaseous components with a higher density than water vapor to superheated water vapor. In our case, such components are gaseous products of thermal decomposition of waste.

 Thus, the vapor-gas mixture will have a higher density, the greater the amount of thermal decomposition gases of wood it contains. At the same time, the production of thermal decomposition gases consumes heat and carbon contained in the wood and is a combustible element, as well as wood oxygen. The removal of carbon from wood leads to a decrease in its calorific value, and the release of oxygen leads to an increase in the calorific value of treated wood. The amount of gases of thermal decomposition of wood also depends on temperature, and with increasing temperature, this amount increases.

Thermal decomposition of wood with a significant emission of gases begins at T = 180 ^o C. Therefore, to obtain a gas-vapor mixture, it is necessary to heat the wood to 180 ^o C and above. When heating wood below 180 ^o C, only moisture and a small amount of CO and CO _{2 are released} , i.e. when heating wood below 180 ^o With it is impossible to obtain a gas mixture with a density higher than the density of water vapor.

When the wood is heated above 320 ^o C, the removal of carbon from the wood sharply increases and the oxygen yield sharply decreases, which entails a sharp drop in the calorific value of the treated wood, since a significant amount of energy in the form of the calorific value of the decomposition gases is removed from the treated mass, and this leads to an increase in energy consumption for the briquetting process, in which case briquettes with a low calorific value are obtained.

Thermal decomposition of wood waste must be carried out at a pressure of P = 1-10 kgf / cm ² without air. When air enters the waste mass, a combustible mixture of decomposition gases and air is formed, which can lead to an explosion, as well as the ignition of the waste. Therefore, to prevent explosions and fires, the pressure of the gas-vapor mixture during waste treatment must be maintained at least 1 atm (1 kgf / cm ² ).

The increase in pressure above 10 kgf / cm ² will lead to the fact that when heated to 180 ^o With waste moisture will not evaporate (the boiling point of water at 10 kgf / cm ² is 180 ^o C), the thermal decomposition process slows down and the vapor-gas mixture will not form . In addition, increasing the pressure above 10 kgf / cm ² will require increasing the metal consumption of the equipment, which means energy consumption for heating and heat loss.

The process of thermal decomposition of waste proceeds with heat absorption in the temperature range Т = 180-275 ^o С and with the release of heat in the range 275-320 ^o С. The intensity of the process is determined by heat exchange with the coolant, i.e. with increasing heat transfer intensity (increasing the amount of heat supplied), the rate of thermal decomposition also increases. One of the factors affecting heat transfer is the density of the coolant, as with increasing density of the coolant, the amount of heat transferred increases.

 The use of a gas-vapor mixture containing water vapor and thermal decomposition products of wood in a mass ratio of (1-20): 1 provides the intensification of heat treatment. When the content of thermal decomposition products in the gas mixture in an amount less than 0.05 kg per 1 kg of water vapor, the density does not change significantly, because water vapor prevails. With an increase in the content of thermal decomposition products in a gas-vapor mixture, its density increases, as a result of which the amount of heat transferred by the mixture increases, because

Q _mixture = C $\genfrac{}{}{0ex}{}{\text{cm}}{\text{p}}$ ρ _cm G _cm ΔT, (2)
where Q _mixture is the amount of heat, kJ / s; C _p ^cm - specific heat of the mixture, kJ / kg ^o C; ρ _cm is the density of the mixture, kg / m ³ ; G _cm is the flow rate of the mixture, kg / s; ΔT = T _inlet -T _outlet - the temperature difference of the mixture at the entrance to the waste layer and at the exit of the layer.

An increase in the content of thermal decomposition products in a gas-vapor mixture of more than 1 kg per 1 kg of water vapor of water vapor leads to an increase in energy consumption for the production of decomposition products, since it is necessary to increase the heating temperature of the waste above 320 ^o C and spend energy on the production of gases with high calorific value.

 To obtain a gas-vapor mixture, it is necessary to evaporate the moisture of the waste. In the case of processing dry waste, it must be moistened to a certain moisture content. The minimum humidity to which dry waste must be moistened must be at least 5 wt.%, I.e. 1 kg of moistened waste should contain at least 0.05 kg of moisture.

 When the moisture content in the waste is less than 5 wt.%, It is impossible to obtain a vapor-gas mixture with a content of water vapor and thermal decomposition products of 20: 1, and also ensure a pressure of at least 1 atm.

 Humidification of the waste to a moisture content of more than 50 wt.% Will require high energy expenditures for evaporation of moisture during the heat treatment and, thus, the energy consumption for the briquetting process will increase sharply, as well as the amount of steam-gas mixture that must be cleaned before being discharged into the environment.

 To prevent the emission of gaseous and liquid products into the environment, it is advisable to use condensate obtained by condensing the spent steam-gas mixture to moisten the waste. At the same time to ensure moisture 5-50 wt. % it is necessary to spend 0.053-1.00 kg of condensate per 1 kg of dry waste.

 The invention is illustrated by the following examples.

 Example 1

 In the chopper 1 serves 500 kg / h of absolutely dry wood waste and grind them to the state of sawdust (1-5 mm in diameter). Next, the crushed waste by pneumatic transport from the grinder 1 is fed into the storage hopper 2, where the moisture content of the waste is measured using a moisture meter 3. From the tank 4 through the water flow meter and crane 6 into the hopper 2 serves (sprayed in the hopper) 500 kg / h of water, which corresponds to a humidity of 50 wt.%. Using the screw 7, the waste is mixed to equalize its moisture, which is controlled by the readings of the moisture meter 3. When achieving uniform wetting of the waste (the moisture meter constantly shows humidity of 50 wt.%), Using the batcher 8, moistened wood waste with a flow rate of 1000 kg / h is fed into the chamber heat treatment 9. At the same time, dry wood waste in the amount of 120.9 kg / h is fed into the furnace 10, they are burned, and the combustion products are sent to the jacket 11 of the heat treatment chamber and then with the help of a smoke exhauster 12 the combustion products are removed into the smoke th tube 13.

 Simultaneously with the supply of waste to the chamber 9, an auger 15 is rotated by the motor 14, which moves the waste from the entrance to the chamber to the exit from it.

In the heat treatment chamber 9, due to the heat of the flue gases (the temperature of the gases at the inlet of the jacket is 1000 ^° C, and leaving the jacket is 200 ^° C), the waste is heated, evaporation of 500 kg / h of moisture, steam overheating, thermal decomposition, as a result of which a gas-vapor mixture containing 500 kg of water vapor superheated to 180 ^{° C.} and 500 kg • 0.05 = 25 kg and thermal decomposition products, which corresponds to a mass ratio of water vapor of thermal decomposition products of 20: 1.

The heat consumption for waste treatment in the chamber 9 will be
_Cams Q = (Q _LOAD ^crushi + Q ⁱⁿ + Q _{isp term)} • 1,1, (3)
Q = C _LOAD ^crushi _p ^crushi M _{crushi crushi} T = 1.9 kJ / kg C ^o • 500 kg / h • (180 ^o C-15 ^o C) = 156750 kJ / h
Q _isp ^a = C _p ⁱⁿ _M (100 ^o C-15 ^o C) ⁿ + C _{p M} (180 ^o C-100 ^o C) 2257 kJ / kg • _M = 4.18 kJ / kg ^o C. • 500kg / h • 85 ^o С + 2 kJ / kg ^o С • 500 kg / h • 80 ^o С + 2257 kJ / kg • 500 kg / h = 1386150 kJ / h
Q _term = q _therm • M _ref = 30 kJ / kg • 500 kg / h = 15000 kJ / h
where C _p ^otx = 1.9 kJ / kg ^o C is the specific heat of absolutely dry wood waste;
With _p ⁱⁿ - specific heat of water;
With _p ^p = 2 kJ / kg ^o C is the specific heat of water vapor;
M _in = 500 kg / h - the mass of evaporated moisture in the chamber 9;
ΔT _exp = (180 ^° C-15 ^° C) - the temperature difference of the waste at the inlet to the chamber (15 ^o C) and at the exit from the chamber (180 ^o C);
(180 ^o C - 100 ^o C) - the value of superheated water vapor;
2257 kJ / kg - heat of evaporation of moisture from the waste;
Q _term = 30 kJ / kg - absorbed heat during decomposition of wood in the range of 150-180 ^o C.

Thus, taking into account 10% heat loss, the heat consumption in chamber 9 will be
_Cams Q = (156750 + 1386150 + 15000) • 1,1 = 1,713,690 kJ / h.

При условии кпд топки 10, равном 75% количество древесных отходов, сжигаемых для обеспечения теплом камеры термообработки составит величину

где Q_н ^р=18900 кДж/кг - теплота сгорания древесных отходов.The power of the heat treatment chamber P = 1713690/3600 = 476 kW
To ensure such heat supply through the jacket of the heat treatment chamber 9, it is necessary to pump the following amount of combustion products

Under the condition that the efficiency of the furnace 10 is 75%, the amount of wood waste burned to provide heat to the heat treatment chamber will be

where Q _n ^p = 18900 kJ / kg - the calorific value of wood waste.

The temperature of heating wood waste in the heat treatment chamber is monitored by the temperature sensor 16, and the composition of the gas mixture is monitored by the gas analyzer 17. To ensure the given composition of the gas mixture and the temperature at the outlet of the chamber T = 180 ^° C, control the number of revolutions of the screw (reduce or increase) and change the amount of combustion products pumped through the jacket 11 with the help of a smoke exhaust fan 12. With a decrease in the content of decomposition products in the gas-vapor mixture (increase in the amount of water vapor, as shown by the device 17) reduce the number of revolutions of the auger, which increases the residence time of the waste in the chamber, and increases the consumption of combustion products through the jacket of the heat chamber and thus set the desired temperature and composition of the gas mixture.

Upon reaching the specified parameters (temperature T = 180 ^o C and the composition of the mixture steam products of decomposition of 20: 1) using the dispenser 18, the treated waste is fed to the press 19 and pressed into briquettes, which are sent to the warehouse on the rolling table 20.

The consumption of treated wood waste through the dispenser 18 will be
500 kg / h - 25 kg / h = 475 kg / h
where 25 kg / h - decomposition products (gaseous) of wood waste.

The vapor-gas mixture formed in chamber 9 creates a pressure, the value of which is monitored by the pressure gauge-regulator 21. In our case, the pressure of the gas-vapor mixture in the heat chamber is 1 atm (1 kgf / cm ² ) using a pressure gauge 21 and an actuator (valve) 22. When the pressure in the chamber 9 is exceeded, the excess vapor-gas mixture through the valve 22 and the valve 23 is supplied to the condenser 24, where, as a result of cooling by the air flow created by the fan 25, it condenses and the condensate is supplied to the accumulator 4, and non-condensable gas is supplied through the valve 26 to the furnace 10 and burned (gas contains CO, CO ₂ , CH ₄ , H ₂ ).

In our case (500 kg of waste), 500 kg of condensate is needed to moisten dry waste to a moisture content of 50 wt.%. Therefore, in order to avoid the accumulation of excess condensate in the tank 4, using a valve 23, 505 kg / h of gas-vapor mixture is supplied to the condenser 24, from which 500 kg / h of condensate is formed (the amount needed to moisten the waste), and 5 kg / h of non-condensing gases (СО , СО ₂ , СН ₄ , Н ₂ ) from the condenser 24 through the valve 26 and 20 kg / h of the gas mixture through the valve 22 and the valve 27 is fed into the furnace 10 and burned.

 Example 2

 In the chopper 1 serves 1000 kg / h of absolutely dry wood waste and grind them to the state of sawdust. Then the crushed waste by pneumatic transport from the grinder 1 is fed into the hopper 2, where the moisture content of the waste is measured using a moisture meter 3. From the tank 4 through the water flow meter 5 and the crane 6 into the hopper 2 serves (sprayed in the hopper) 52.7 kg / h of water, which corresponds to a moisture content of 5 wt.%. Using the screw 7, the waste is mixed to equalize its moisture, which is controlled by the readings of the moisture meter 3. When the waste is evenly moistened (the moisture meter constantly shows a moisture content of 5 wt.%), Using the batcher 8, moistened wood waste with a flow rate of 1052.6 kg / h is supplied into the heat treatment chamber 9. At the same time, dry wood waste in the amount of kg / h is supplied to the furnace 10, they are burned, and the combustion products are sent to the jacket 11 of the heat treatment chamber and then, with the help of a smoke exhaust fan 12, the combustion products are led into the smoke pipe 13. Simultaneously with the motor 14 is driven to rotate the screw 15 which moves the waste into the chamber from the entrance 9 to the exit therefrom.

In the heat treatment chamber 9, the waste is heated to a temperature of 320 ^° C. As a result of heating, 52.7 kg / h of waste moisture evaporates, steam overheats, wood decomposes thermally to form a gas-vapor mixture containing 52.7 kg of superheated water vapor and 52.7 kg of waste decomposition products.

 The temperature of heating wood waste in the chamber 9 is monitored by the temperature sensor, and the content of superheated water vapor in the mixture is monitored by the readings of the gas analyzer 17.

When these parameters deviate from the set (T = 320 ^o C, the ratio of steam-decomposition products is 1: 1) they are regulated by changing the flow rate of the combustion products and the speed of rotation of the screw 7.

In the heat treatment chamber 9, heat from flue gases (combustion products) is spent on heating waste to 275 ^o C in the amount of:
Q _LOAD ^crushi = 1.9 kJ / kg C ^o • 1000 kg / h • (275 ^o C-15 ^o C) = 494000 kJ / h
Part of the heat of the combustion products is spent on the evaporation of moisture from the waste and overheating of the steam to 275 ^o C:
Q _isp ⁱⁿ = 4,18 kJ / kg • ^o C. 52.7 kg / h • 85 ^o C + 2 kJ / kg • ^o C. 52.7 kg / h • (275 ^o C-100 ^o C) 2257 kJ / kg • 52.7 kg / h = 156113.2 kJ / h
The heat of the combustion products is also spent on thermal decomposition:
Q _term = q _therm • M _ref = 863.3 kJ / kg • 1000 kg / h = 863300 kJ / h
where q _term = 863.3 kJ / kg is the average in the temperature range (180-275) ^o С the heat spent on thermal decomposition of waste.

При условии, что кпд топки 10 составляет 75% количество древесных отходов, сжигаемых для обеспечения теплом камеры термообработки составит величину:

По достижении температуры в камере термообработки 275^oС процесс термического разложения переходит из эндотермической в экзотермическую стадию, т. е. тепло уже не поглощается, а выделяется [6].Thus, taking into account 10% heat loss, the heat consumption in the chamber 9 when heating the waste to T = 275 ^o C will be
_Cams Q = (494000 kJ / kg + 156,113 kJ / h + 863,300 kJ / h) • 1,1 = 1664754,5 kJ / h
Chamber power 9 P = 462.4 kW
To ensure such heat supply through the jacket of the chamber 11, it is necessary to pump the following amount of combustion products

Provided that the efficiency of the furnace 10 is 75%, the amount of wood waste burned to provide heat to the heat treatment chamber will be:

Upon reaching a temperature in the heat treatment chamber of 275 ^o С, the process of thermal decomposition passes from the endothermic to the exothermic stage, that is, the heat is no longer absorbed, but released [6].

The following amount of heat must be used to heat the waste from 275 ^o C to 320 ^o C
Q _LOAD ^crushi = 1.9 kJ / kg C ^o • (1,000 kg / hr, 52.7 kg / h) • (320 ^o C-275 ^o C) = 80994.2 kJ.

Heat is expended on overheating of the vapor-gas mixture from 275 ^o С to 320 ^o С
Q _per ^cm = C _p ^cm M _cm T = 2 kJ / kg ^o C (52.7 kg / h + 52.7 kg / h) • (320 ^o C-275 ^o C) = 9486 kJ / h
Given 10% heat loss, the heat consumption at the stage of heating the waste from 275 ^o C to 320 ^o C will be:
Q _LOAD ^crushi = 1.1 (80994.2 kJ / hr + 9486 kJ / hr) = 99473 kJ / h.

Поскольку при нагревании от 275^oС до 320^oС выделяется тепло, то во избежании перегрева отходов выше 320^oС необходимо в соответствии с показаниями датчика температуры уменьшать расход дымовых газов (продуктов сгорания отходов) через рубашку камеры 9 и удерживать (регулируя расход дымовых газов) температуру отходов Т=320^oС на выходе из камеры 9.To ensure heat supply to the chamber 9 at the stage of heating the waste from 275 ^o C to 320 ^o C, it is necessary to burn the following amount of fuel (wood waste)

Since heat is generated when heating from 275 ^o C to 320 ^o C, in order to avoid overheating of the waste above 320 ^o C, it is necessary, in accordance with the temperature sensor, to reduce the consumption of flue gases (waste combustion products) through the jacket of the chamber 9 and hold it (by adjusting the consumption of flue gases ) the temperature of the waste T = 320 ^o With the exit from the chamber 9.

Upon reaching the specified parameters (temperature T = 320 ^o C and the composition of the mixture of steam-decomposition products 1: 1) using the dispenser 18, the processed waste is fed to the press 19 and pressed into briquettes, which are sent to the warehouse via the rolling table 20.

The output of briquettes is
1000 kg / h - 52.7 kg / h = 947.3 kg / h
The vapor-gas mixture formed in the chamber 9 creates a pressure, the value of which is observed according to the testimony of the pressure gauge-regulator 21. In our case, using the manometer 21 and the actuator 22, the pressure of the gas-vapor mixture in the chamber 9 is set to 10 atm. When the pressure in the chamber 9 is exceeded, the excess vapor-gas mixture through the valve 22 and the valve 23 is supplied to the condenser 24, where, as a result of cooling by the air flow created by the fan 25, it condenses and the condensate is supplied to the accumulator 4, and non-condensable gas is supplied through the valve 26 to the furnace 10 and burned.

 In our case, 52.7 kg of condensate (i.e., 0.053 kg per 1 kg of dry waste) is required to moisten dry waste to a moisture content of 5 wt.%. Therefore, in order to avoid the accumulation of excess condensate in the tank 4 by means of a valve 23, 63 kg / h of gas-vapor mixture is supplied to the condenser 24, from which 52.7 kg / h of condensate is formed, and 10.3 kg / h of non-condensable products from the condenser 24 through the valve 26 and 42.4 kg / h of the gas mixture through the valve 22 and the valve 27 is fed into the furnace 10 and burned.

Claims (2)

1. The method of briquetting waste, including crushing it, processing the crushed waste with a coolant and subsequent pressing, characterized in that after grinding the waste is moistened to a moisture content of 5-50 wt. % by supplying water, and as a heat carrier using a gas-vapor mixture containing water vapor and products of thermal decomposition of waste in a mass ratio (1-20): 1, which is obtained by evaporation of moisture from the waste and thermal decomposition of the latter at a temperature of 180-320 ^o С and a pressure of 1-10 kgf / cm ² .  2. The method according to p. 1, characterized in that for the humidification of the waste use condensate in an amount of 0.053-1.0 kg per kilogram of waste, which is obtained by condensation of the spent vapor-gas mixture.

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