RU2840948C1 - Coal slurry combustion device - Google Patents

Abstract

FIELD: combustion apparatus.

SUBSTANCE: invention relates to destruction of wastes or low-grade fuels by combustion, namely, to devices intended for combustion of coal slurry. Coal slurry combustion device includes combustion chamber (1) in the form of parallelepiped. Front wall of combustion chamber is equipped with door with window (2). Fan (7) is connected to the hole in the first side wall of combustion chamber (1) by means of an air duct. Into the central part of the second side wall of combustion chamber (1) in parallel to bottom injector (3) is mounted, on both sides of which in parallel to the bottom two electrodes (4) are mounted, and above injector (3) the first temperature sensor (5) is mounted. Second temperature sensor (6) is mounted into the upper wall of combustion chamber (1). Injector (3) is connected by pipeline to first compressor (8) and through valve (9) to hole in cover of dissociation unit (10) that is made in the form of cylindrical reservoir with double side walls, between which there located is electric heating cable (11). A third temperature sensor (12) and pressure sensor (13) are mounted into the cover of dissociation unit (10). In combustion chamber (1) second side wall lower part at angle of 60° burner (14) is mounted relative to its bottom, which is connected by a pipeline through second compressor (15) to coal slurry storage tank (16) equipped with vibration device (17). Combustion chamber (1) top part communicates via first sidewall hole with heat exchanger (18) accommodating coiled pipe (19) with its ends extending outward and connected to tank filled with water (20). One end of pipe (19) is equipped with pump (21) and fourth temperature sensor (22), and second end of pipe (19) is equipped with fifth temperature sensor (23). Chimney (24) is led upwards from heat exchanger (18) and is equipped with gas analyser (25), sixth temperature sensor (26) and exhaust fan (27). Control cabinet (28) contains piezoelement (29), heater (30) and power supply (31), which are connected to programmable logic controller (32) connected to personal computer (33). Electrodes (4) are connected to piezoelement (29). Heater (30) is connected to electric heating cable (11) of dissociation unit (10). Temperature sensors (5, 6, 12, 22, 23 and 26), fan (7), compressors (8, 15), valve (9), pressure sensor (13), vibration device (17), pump (21), gas analyser (25) and exhaust fan (27) are connected to programmable logic controller (32).

EFFECT: stable combustion process; invention allows for stable combustion of coal slurry.

1 cl, 3 dwg

Description

The invention relates to the field of destruction of waste or low-grade fuels by combustion, namely to devices intended for combustion of coal sludge.

A device is known for burning low-grade and low-reactivity solid fuels [RU 93032 U1, IPC B01D 29/72 (2006.01), B01D 35/00 (2006.01), published 20.04.2010], comprising a vortex furnace with a vertical axis with a gas outlet window located along the furnace axis, secondary air blast nozzles and a slag unloader located at the bottom of the furnace, a convective bundle with a fly ash return system, and a crushed coal feeder. The vortex furnace is additionally equipped with burner devices with nozzles for feeding suspended coal fuel, located in one or more tiers opposite each other. Secondary blast nozzles are located at the same levels. In this case, the burner devices with nozzles are located evenly between the secondary blast nozzles. The directions of the jets of suspended coal fuel sprayed by primary air coincide with the direction of the secondary blast flows and the nozzles of the entrainment return system. The diameter of the conventional cylindrical surface, tangential to which the supply of suspended coal fuel, secondary air and sharp blast with entrainment return to the vortex furnace is organized, is smaller than the diameter of the pinch window of the latter.

However, this device does not have a flue gas cooling system and uses coal as a high-calorie fuel, which leads to high levels of harmful gas emissions.

A device for burning a mixture of solid low-grade fuel with methane hydrate granules is known [RU 2815849 C1, IPC F23G 5/00 (2023.01), published 03/22/2024], selected as a prototype, containing a combustion chamber in the form of a parallelepiped, inside which one side wall is equipped with a heating element connected to a temperature control unit. The temperature control unit is connected to a power source. An inlet for feeding a mixture of solid low-grade fuel with methane hydrate granules is made at the top of the combustion chamber. A temperature sensor is mounted inside the combustion chamber, which is connected to the temperature control unit. A spark ignition unit is connected to the power source, to which two electrodes are connected, mounted inside the combustion chamber through two adjacent side walls perpendicular to each other. A nozzle is mounted in the upper part of the combustion chamber, which is connected to an air source made in the form of a compressor unit. At the bottom of the combustion chamber there is an outlet with a cover. A probe is mounted in the upper part of the side wall of the combustion chamber, which is connected to a gas analyzer connected to a personal computer.

In this device, solid low-grade fuel is fed together with methane hydrate granules, so at high temperatures, methane hydrate dissociates, accompanied by the formation of a large amount of water, which disrupts the stability of the fuel combustion process.

The technical result of our proposed invention is the creation of a device that ensures stable combustion of coal sludge.

The proposed device for burning coal sludge, just like the prototype, contains a power source, a personal computer, a gas analyzer, a combustion chamber connected to an air source, made in the form of a parallelepiped, inside which two electrodes and the first temperature sensor are mounted.

According to the invention, the front wall of the combustion chamber is provided with a door with a window. A fan is used as an air source, which is connected via an air duct to an opening in the first side wall of the combustion chamber. A nozzle is mounted in the central part of the second side wall of the combustion chamber parallel to the bottom, on both sides of which two electrodes are mounted parallel to the bottom, and the first temperature sensor is mounted above the nozzle. A second temperature sensor is mounted in the upper wall of the combustion chamber. The nozzle is connected via a pipeline to the first compressor and via a valve is connected to an opening in the cover of the dissociation unit, which is made in the form of a cylindrical container with double side walls, between which an electric heating cable is located. A third temperature sensor and a pressure sensor are mounted in the cover of the dissociation unit. A burner is mounted in the lower part of the second side wall of the combustion chamber at an angle of 60° relative to its bottom, which is connected via a pipeline through the second compressor to a tank for storing coal sludge, equipped with a vibration device. The upper part of the combustion chamber is connected through an opening in the first side wall to a heat exchanger, inside of which is a snake-shaped curved pipe, the ends of which are brought out and connected to a tank filled with water. One end of the pipe is equipped with a pump and a fourth temperature sensor, and the second end of the pipe is equipped with a fifth temperature sensor. A chimney equipped with a gas analyzer, a sixth temperature sensor and a smoke exhauster is led upward from the heat exchanger. The control cabinet contains a piezoelectric element, a heater and a power source, which are connected to a programmable logic controller connected to a personal computer. Electrodes are connected to the piezoelectric element. The heater is connected to the electric heating cable of the dissociation unit. Temperature sensors, a fan, compressors, a valve, a pressure sensor, a vibration device, a pump, a gas analyzer and a smoke exhauster are connected to the programmable logic controller.

The proposed design allows adding methane extracted from methane hydrate to coal sludge, which increases the calorific value of the fuel and ensures a stable combustion process.

Water vapor formed during the dissociation of methane hydrate reduces the concentration of anthropogenic substances in the flue gases: carbon monoxide CO, nitrogen oxides NO _x , sulfur oxide SO ₂ . The presence of a heat exchanger, in which the temperature of the flue gases is reduced, leads to a decrease in the concentration of CO, NO _x , SO ₂ emissions and allows the use of heated water for industrial purposes.

The coal sludge combustion device allows not only to utilize coal industry waste, but also to use it as an alternative fuel for generating thermal energy.

Fig. 1 shows a diagram of a device for burning coal sludge.

Fig. 2 shows a sectional view of the combustion chamber from above.

Fig. 3 shows the structural diagram of the control cabinet.

The device for burning coal slurry comprises a steel combustion chamber 1 in the form of a parallelepiped on four supports (Fig. 1). In the front wall of the combustion chamber 1 there is a door with a window 2. In the central part of the first side wall of the combustion chamber 1 a nozzle 3 is mounted parallel to the bottom. Inside the combustion chamber 1 on both sides of the nozzle 3 parallel to the bottom two electrodes 4 are mounted (Fig. 2). In the first side wall of the combustion chamber 1 above the nozzle 3 a first temperature sensor 5 is mounted. In the central part of the upper wall of the combustion chamber 1 a second temperature sensor 6 is mounted (Fig. 1). An opening in the second side wall of the air duct connected to fan 7.

The nozzle 3 is connected by pipelines to the first compressor 8 (K1) and through the valve 9 to the dissociation unit 10, which is a cylindrical container with a lid. The dissociation unit 10 is made with double side walls, between which the electric heating cable 11 is located. The third temperature sensor 12, the pressure sensor 13 are mounted in the lid of the dissociation unit 10.

A burner 14 is mounted in the lower part of the first side wall of the combustion chamber 1 at an angle of 60° relative to its bottom, which is connected by a pipeline through a second compressor 15 (K2) to a tank for storing coal sludge 16 (BU), which is equipped with a vibration device 17 (VU).

The upper part of the combustion chamber 1 is connected through an opening in the second side wall to the heat exchanger 18, inside which a snake-shaped curved pipe 19 is located, the ends of which are led out and connected to a tank filled with water 20 (WT). One end of the pipe 19 is equipped with a pump 21 and a fourth temperature sensor 22. The second end of the pipe 19 contains a fifth temperature sensor 23. From the heat exchanger 18 a chimney 24 is led upward, containing a gas analyzer 25 (GA), a sixth temperature sensor 26 and a smoke exhauster 27.

Control cabinet 28 (CC) contains piezoelectric element 29 (PE), heater 30 (H) and power source 31 (PS), which are connected to programmable logic controller 32 (PLC), connected to personal computer 33 (PC) (Fig. 3).

Electrodes 4 are connected to piezoelectric element 29 (PE). Electric heating cable 11 is connected to heater 30 (H). The first 5, second 6, third 12, fourth 22, fifth 23 and sixth 26 temperature sensors, fan 7, first compressor 8 (K1), valve 9, pressure sensor 13, second compressor 15 (K2), vibration device 17 (VU), pump 21, gas analyzer 25 (GA) and smoke exhauster 27 are connected to programmable logic controller 32 (PLC).

The first 8 (K1) and the second 15 (K2) compressors are VD RealArm SMART (1800W) compressors, the vibration device 17 (VU) is the NetterVibration NEA series electric vibrator, the gas analyzer 25 (GA) is the Test-1 gas analyzer, and the power source 31 (PS) is the Oven BP60A-24 power supply unit. The programmable logic controller 32 (PLC) of the Oven PLC200 brand is used.

In dissociation unit 10, after removing the lid, methane hydrate in a volume of 300 ml is poured. Then the lid is closed and using the program from personal computer 33 (PC) a signal is sent to programmable logic controller 32 (PLC) to start heater 30 (H), which heats electric heating cable 11. In dissociation unit 10 the temperature is increased to 70°C. Under the influence of high temperature, methane hydrate dissociates into gas and water. Temperature and pressure in dissociation unit 10 are measured using third temperature sensor 12 and pressure sensor 13. Data from third temperature sensor 12 and pressure sensor 13 are sent to programmable logic controller 32 (PLC), from where they are transmitted to personal computer 33 (PC). As the amount of gas in dissociation unit 10 increases, the pressure increases. When the pressure in the dissociation unit 10 reaches 20 bar, the programmable logic controller 32 (PLC) sends a signal to switch off the heater 30 (H) and open the valve 9. Under the action of the pressure, methane enters the combustion chamber 1 through the injector 3. At the same time, the programmable logic controller 32 (PLC) starts the first compressor 8 (K1), which supplies air to the combustion chamber 1 through the injector 3. Then, the programmable logic controller 32 (PLC) sends a signal to the piezoelectric element 29 (PE) to supply current to the electrodes 4. A short circuit occurs between the electrodes 4, which leads to the appearance of an electric discharge arc that ignites the gas-air mixture. The temperature of the gas-air torch is measured by the first temperature sensor 5, and the temperature in the combustion chamber 1 is measured by the second temperature sensor. Data from the first 5 and second 6 temperature sensors are fed to the personal computer 33 (PC) via the programmable logic controller 32 (PLC). Using the program in the personal computer 33 (PC), a signal is sent to the programmable logic controller 32 (PLC) to start the vibration device 17 (VU), which prevents the fuel particles from sticking together in the coal sludge storage tank 16 (BU). When the temperature in the combustion chamber reaches 500°C, the programmable logic controller 32 (PLC) sends a signal to start the second compressor 15 (K2), which supplies air to the coal sludge storage tank 16 (BU). There, the air is mixed with the pulverized coal sludge and the finished mixture is fed under pressure to the combustion chamber 1 via the burner 14. The pulverized coal mixture, passing through the gas-air torch, is ignited. In order to maintain the required excess air, air is additionally supplied to the combustion chamber 1 by means of a fan 7, which is started by means of a programmable logic controller 32 (PLC) in response to a signal coming from a personal computer 33 (PC). Flue gases are removed from the combustion chamber 1 through a chimney 24 by means of a smoke exhauster 27, which is started by means of a programmable logic controller 32 (PLC) in response to a signal coming from a personal computer 33 (PC). Before entering the chimney 27, the flue gases pass through a heat exchanger 18, heating the water circulating through a pipe 19 from a tank filled with water 20 (BV) to the heat exchanger 18 and back. Water circulation is provided by a pump 21, which is started by means of a programmable logic controller 32 (PLC) in response to a signal coming from a personal computer 33 (PC). The temperature of water at the outlet of the tank filled with water 20 (EB) and at the inlet to it is measured by the fourth 22 and fifth 23 temperature sensors, respectively. The signal from the fourth 22 and fifth 23 temperature sensors is transmitted to the personal computer 33 (PC) via the programmable logic controller 32 (PLC). The composition of the flue gases at the outlet of the heat exchanger 18 is recorded using the gas analyzer 25 (GA), the data from which are transmitted to the personal computer 33 (PC) via the programmable logic controller 32 (PLC). The temperature of the flue gases is measured in the chimney 24 using the sixth temperature sensor 26, the data from which are transmitted to the personal computer 33 (PC) via the programmable logic controller 32 (PLC). The flue gases, passing through the heat exchanger 18, are cooled. As the temperature decreases, the concentration of harmful anthropogenic substances in their composition decreases.

Claims (1)

A device for burning coal sludge, comprising a power source (31), a personal computer (33), a gas analyzer (25), a combustion chamber (1) connected to an air source, made in the form of a parallelepiped, inside which two electrodes (4) and a first temperature sensor (5) are mounted, characterized in that the front wall of the combustion chamber is provided with a door with a window (2), a fan (7) is used as an air source, which is connected via an air duct to an opening in the first side wall of the combustion chamber (1), a nozzle (3) is mounted in the central part of the second side wall of the combustion chamber (1) parallel to the bottom, on both sides of which two electrodes (4) are mounted parallel to the bottom, and a first temperature sensor (5) is mounted above the nozzle (3), a second temperature sensor (6) is mounted in the upper wall of the combustion chamber (1), the nozzle (3) is connected via a pipeline to the first compressor (8) and through a valve (9) to an opening in the cover of the dissociation unit (10), which is made in the form of a cylindrical container with double side walls, between which an electric heating cable (11) is located, a third temperature sensor (12) and a pressure sensor (13) are mounted in the cover of the dissociation unit (10), a burner (14) is mounted in the lower part of the second side wall of the combustion chamber (1) at an angle of 60° relative to its bottom, which is connected by a pipeline through a second compressor (15) to a tank for storing coal sludge (16), equipped with a vibration device (17), the upper part of the combustion chamber (1) is connected through an opening in the first side wall to a heat exchanger (18), inside which a serpentine-shaped curved pipe (19) is located, the ends of which are led outward and connected to a tank filled with water (20), wherein one end of the pipe (19) is equipped with a pump (21) and a fourth temperature sensor (22), and the second end of the pipe (19) is equipped with a fifth temperature sensor (23) , from the heat exchanger (18) up a chimney (24) is led out, equipped with a gas analyzer (25), a sixth temperature sensor (26) and a smoke exhauster (27), the control cabinet (28) contains a piezoelectric element (29), a heater (30) and a power source (31), which are connected to a programmable logic controller (32) connected to a personal computer (33), wherein electrodes (4) are connected to the piezoelectric element (29), the heater (30) is connected to the electric heating cable (11) of the dissociation unit (10), and temperature sensors (5, 6, 12, 22, 23 and 26), a fan (7), compressors (8, 15), a valve (9), a pressure sensor (13), a vibration device (17), a pump (21), a gas analyzer (25) and a smoke exhauster (27) are connected to the programmable logic controller (32).