RU2154237C1 - Device for burning combustible materials and wastes - Google Patents

Abstract

FIELD: burning combustible materials and wastes, for example, soil contaminated by petroleum products. SUBSTANCE: device has housing with air supply branch pipe and combustion product discharge branch pipe, loading bin, two combustion chambers located in housing, air supply unit and grid. Combustion chambers and grid are located coaxially relative to one another; wall of inner chamber has holes for passage of gas. Cross section of grid reduces towards bin. EFFECT: possibility of self-distributing of air heated to autoignition temperature of gas; obtaining required degree of filtration; complete combustion of coke and afterburning of gas. 9 cl, 1 dwg

Description

 The invention relates to the field of burning of combustible materials and waste, in particular, it can be used to create more advanced devices for burning various capacities operating on waste.

 A device for burning combustible materials and waste is known, comprising a housing with nozzles for supplying air and exhausting combustion products, a loading hopper and at least two combustion chambers, an air supply unit and a grill placed in the housing (SU 1615463 A1, 23.12.90).

 The disadvantages of the known device are the inability to ensure a continuous process of burning materials, the complexity of the air distribution systems and the system for moving combustion products.

 The technical result is the provision of self-distribution of air heated to a temperature of self-ignition of the gas in the required quantities, providing the necessary degree of filtration in various combustion zones, achieving complete coke burning and gas afterburning, ensuring a continuous combustion process to the final combustion products by transferring heat from the external combustion chamber to the internal and preheating the air in the device itself, simplifying the design and increasing efficiency.

 The technical result is achieved by the fact that the device for burning combustible materials and waste comprises a housing with nozzles for supplying air and exhausting combustion products, a loading hopper and at least two combustion chambers, an air supply unit and a grill, combustion chambers and a grill placed coaxially to each other to a friend, while the wall of the inner chamber is made with openings for the passage of gas, and the lattice with a cross section decreasing towards the bunker. The device is equipped with a separator located under the grate. Pipes for supplying air and exhausting combustion products form a pipe-in-pipe heat exchanger. The device is equipped with a fan installed in the branch pipe of the combustion products. The inner chamber is made in the form of rings decreasing in the direction of the hopper diameter, installed in each other with the formation of gaps, while the holes are formed by gaps. The grill is made in the form of a set of plates placed with a gap for the passage of air one above the other and increasing in size to the base with the formation of a truncated cone. The grill is equipped with transverse rods and mounted with the possibility of rotation around its axis. The supply unit is made in the form of an air supply pipe connected via pipes to the collector formed by the lower ring of the inner chamber, while the collector covers the internal combustion chamber. The device is equipped with at least one channel for the passage of air into the external combustion chamber with the possibility of regulating its supply.

 The drawing shows a device in section.

 The fuel mass for use in the proposed device can be any combustible materials and waste. As an example, the most inconvenient of them is soil contaminated with oil products (fuel oil). When the fuel oil content is 10-15% (the rest is sand), such combustible material is a pasty or loose mass with very low gas permeability. Burning such a fuel mass in its pure form in the embodiment of filtration combustion is not feasible. It is necessary to adjust the composition with additional additives to obtain optimal component ratios, for which wood sawdust is added to the composition except for sand. A device for burning combustible materials and waste consists of two adjacent combustion chambers 4 located in the housing 15 with a grill 3 and an external combustion chamber 2 located around it with a common wall 12 between them. The lower part of the wall 12 closes in the air collector 5, which surrounds the inner chamber, being in the outer combustion chamber, and together with the grill is a single unit. The grill 3 consists of a set of plates 13 with a gap between them for the passage of air. The wall is formed by a set of rings 14 inserted one into another with a gap for the passage of air and the output of pyrolysis products from the internal to the external combustion chamber. At the bottom of the collector and grille are a separator 9 of combustion products and a heat exchanger for preheating air 8.

 The device, in addition, contains a pipe 11 for supplying air, a pipe 7 for removal of combustion products, a hopper 1, a channel 6 for passage of air into the external chamber 2 and a shutter 10 for discharging solid combustion products.

An exhaust fan (not shown in the drawing) exhausts combustion products (exhaust flue gases) from both combustion chambers. Due to the vacuum generated by the fan, combustion air and afterburning are self-sucked into the grill 3 and the collector 5. The intake air, passing through the heat exchanger 8 and the separator 9, is preheated to 200-250 ^o C. Finally, the air entering the oxidation reaction is heated to the self-ignition temperature of the combustible gases, passing through the grate 3 between the plates 13, and in the collector 5, which is washed by suction products of combustion from the external combustion chamber 2 (collector tubes are washed by suction products from the internal chamber). Air is distributed between the combustion chambers. Part of the air goes to the grill 3, passes between the plates 13, and is spent in the inner chamber 4 on the combustion of the fuel mass (pyrolysis and the formation of volatile combustible components, burnout of hardly volatile components and coke). Another part of the air through the tubes 16 is directed to the manifold, from which air enters the internal combustion chamber 4 through the wall 12 (and is consumed for burning the fuel mass along with part of the air entering through the grill) and into the external combustion chamber 2 through the annular gap in the top cover collector and is spent on burning and afterburning of volatile combustible components entering through the wall from the inner chamber. Provides automatic self-adjustment of the process with changes in its burning rate. To adjust the afterburning of volatile combustible gases, a separate additional channel 6 for self-priming of air with heating is used due to the heat of the external combustion chamber. The fuel mass is loaded from above through the hopper 1 of the feeder. As it burns out, the fuel mass drops by gravity. When releasing the upper part of the feeder to a certain level, the fuel mass is periodically recharged. The feed opening in the hopper 1 does not require sealing and is constantly in the open state. The aspirated combustion products are separated, the solid condensed phase accumulates at the bottom and is periodically discharged through the bottom damper 10.

 The combustion zones of the fuel mass are in the grating region. The maximum temperature is set in the lower part of the grate and gradually decreases towards its top and bunker. Below the upper part of the grate, the volatile components of fuel oil are already distinguished. Above the grate there is a zone in which the emission of volatile components and pyrolysis products of fuel oil and wood takes place. Volatile products through the wall 12 go into the external combustion chamber 2, where they are burned in the air coming from the collector 5. In the combustion zone of the hardly volatile and coking components (in the lower part of the lattice) coke is formed and burns. The coke residue on sand particles consists mainly of carbon, the oxidation rate of which is highly dependent on temperature and oxygen concentration. The use of a combustion chamber of this design with a wall with holes and a grill provides reliable air access to the combustion zones (with self-distribution in the required quantities and ensuring the necessary filtration rate in various combustion zones). In this case, the main air flow does not go towards the flow of combustible mass, but perpendicular to it, through its relatively small layer (from two opposite directions). The taper of the combustion chamber and the grate gradually reduces this layer to a minimum towards the end of the coke burnout and, in turn, also allows to gradually increase the air flow towards the end of the burnout and thereby burn out coke on sand particles faster and easier. At the same time, part of the air, together with the combustion products of the coke residue, is spent on removing sand released from coke through the gap between the lower edge of the conical grate 3 and the lower ring of the perforated wall 12 of the combustion chamber. The organization of the combustion process of the fuel mass in the internal combustion chamber is such that the reaction products flowing along the height of the combustion chamber move in two directions (up and down). Pyrolysis products, volatile components and part of the non-volatile components move up to burn in the external combustion chamber. Moving down the combustion products of coke and the main part of the hard-to-volatile components, carrying with it the sand that is newly freed from coke.

 To start the device, it is necessary to warm up the combustion chambers with some full-fledged fuel (for example, wood waste), and then load the working mixture.

Claims (9)

 1. A device for burning combustible materials and waste, comprising a housing with pipes for supplying air and exhausting combustion products, a loading hopper, and at least two combustion chambers, an air supply unit and a grill housed in the housing, characterized in that the combustion chambers and grill are coaxial with each other, while the wall of the inner chamber is made with openings for the passage of gas, and the lattice with a decreasing cross-section to the bunker.  2. The device according to claim 1, characterized in that it is equipped with a separator located under the grate.  3. The device according to claims 1 and 2, characterized in that the pipes for supplying air and exhausting combustion products form a pipe-in-pipe heat exchanger.  4. The device according to claims 1 to 3, characterized in that it is equipped with a fan installed in the branch pipe of the combustion products.  5. The device according to claim 1, characterized in that the inner chamber is made in the form of rings decreasing in the direction of the hopper diameter installed in each other with the formation of gaps, while the holes are formed by gaps.  6. The device according to paragraphs. 1 and 5, characterized in that the lattice is made in the form of a set of plates placed with a gap for the passage of air one above the other and increasing in size to the base with the formation of a truncated cone.  7. The device according to claim 6, characterized in that the lattice is provided with transverse rods and mounted to rotate around its axis.  8. The device according to claims 1, 5 and 6, characterized in that the air supply unit is made in the form of an air supply pipe connected via pipes to a collector formed by the lower ring of the inner chamber, while the collector covers the inner combustion chamber.  9. The device according to p. 1, characterized in that it is equipped with at least one channel for the passage of air into the external combustion chamber with the possibility of regulating its supply.