RU2180079C2 - Method of processing wastes of petroleum products at high content of mineral sediments - Google Patents

Abstract

FIELD: utilization of ground contaminated with petroleum products, and mineral sediments from mazut and oil storages. SUBSTANCE: proposed method consists in delivery of wastes together with solid fuel and air to combustion chamber; air is supplied in excess for conducting combustion reactions in continuous burning process to final gaseous products and solid mineral residue; solid residue is continuously removed from reaction zone; combustion reactions of wastes and fuel are carried out in gas permeable volume; combustion reactions of volatile components of wastes and fuel are conducted in free volume of combustion chamber which embraces coaxially volume with wastes and fuel and is communicated with it through common gas permeable perforated wall. EFFECT: possibility of ensuring self-distribution of air in combustion zone in required amount; enhanced degree of filtration in fuel mass; complete combustion of coke and after-burning of gases; continuity of combustion process to final combustion products. 7 cl, 1 dwg

Description

 The invention relates to methods for the disposal of wastes containing petroleum products, in particular, can be used in the technology of environmentally friendly disposal of soil contaminated with oil products, mineral sediments from fuel oil storages and oil storage facilities.

 A known method of burning combustible materials and waste (SU 1615463 A1, 12/23/90).

 The disadvantages of this method is the inability to provide a continuous process of burning materials, the complexity of the air distribution system and the system of moving combustion products.

 The prototype of the invention is a method of processing waste containing hydrocarbons (RU 2116570 C1, 07.27.98), in which the waste is loaded into the reactor together with an inert solid non-combustible material (pieces of refractories). The amount of inert material in the charge is more than 80 wt.%. When burning petroleum products mixed with mineral particles, the proportion of inert material in the charge increases even more (since the content of mineral particles in petroleum products also usually is at least 80 wt.%). Processing in this way waste oil products with a high content of mineral deposits becomes difficult due to the predominance of inert non-combustible material (mineral sludge from waste and refractory filler).

 The objective of the technical solution is to develop a method for processing petroleum waste with a high content of mineral deposits, eliminating these difficulties.

 The problem is solved by the claimed processing method, in which waste together with solid fuel and air with some excess are fed to the combustion chamber for conducting combustion reactions in a continuous combustion process to the final gaseous products and solid mineral residue, the solid residue is continuously removed from the reaction zone. The reaction of burning waste and fuel is carried out in a gas-permeable volume, and the reaction of burning of volatile combustible components of waste and fuel is carried out in the free volume of the combustion chamber, which coaxially covers the volume of waste and fuel and communicates with it through a common gas-permeable, perforated wall. Waste is mixed with solid fuel before loading into the combustion chamber to form a fuel mass. As solid fuel use wood waste and any other types of solid fuel. The fuel mass is fed into the combustion chamber, and the solid residue is removed from it periodically. Air is fed into the combustion chamber continuously in a quantity sufficient for complete combustion of the fuel mass and combustible gases, and additionally with the possibility of controlling its supply. Air in the volume with the fuel mass is directed perpendicular to the flow of fuel mass from two opposite directions through the perforated wall and the conical grate along their height and, when passing into the reaction zone, they are heated in the combustion chamber to the temperatures of the reactions occurring in it.

 The essence of the invention lies in the fact that self-distribution of air in the combustion zone in the required quantities, heated to the temperature of self-ignition of combustible gases, provides the necessary degree of filtration in the fuel mass, ensures the complete burning of coke and afterburning of gases, the continuity of the combustion process to the final combustion products. There is no need to use a refractory filler (inert solid non-combustible material). The gas permeability of the charge is provided by the mineral sediment in the waste, solid fuel and the design features of the combustion chamber.

 The technical solution is achieved by the fact that in the method of processing petroleum waste with a high content of mineral precipitation, waste is supplied to the combustion chamber together with solid fuel, air with some excess, and combustion reactions are carried out in a continuous process to the final gaseous products and solid residue, which is continuously removed from reaction zone. The combustion reaction of the fuel mass (waste mixture with solid fuel) takes place in a gas-permeable volume bounded by a conical grating and an internal perforated wall, and the combustion reaction of the resulting combustible gases occurs in the free volume of the combustion chamber, which coaxially covers the volume with the fuel mass and is formed by the inner and outer walls and bars. Combustible gases leave the volume with the fuel mass in the free volume of the combustion chamber through a common perforated wall and burn in it to the final products. The air heated in the combustion chamber enters the volume with the fuel mass through the perforated wall and the grill perpendicular to the flow of the fuel mass, and into the free volume of the combustion chamber. The air enters continuously in a quantity sufficient for complete combustion of the fuel mass and combustible gases, and additionally for regulating the afterburning of gases.

 Known combustion chamber for combustible materials and waste (RU 12458 U1, 10.01.2000) used in the invention. The drawing shows a schematic diagram of a combustion chamber, which consists of two parts located in the housing 10 - a volume with a fuel mass 4 (inner chamber) with a grill 3 for burning the fuel mass itself, and a free volume 2 (outer chamber) for burning gases. The free volume of the combustion chamber 2 is located around the volume with the fuel mass 4 and has a common perforated wall with it 12. Like the grill 3, the inner wall 12 is made with openings for gas passage. The air manifold 5 is a grid with a grid 3 and a wall 12. The combustion chamber contains a pipe 6 for supplying air, a pipe 7 for removal of combustion products, a fuel loading hopper 1, an additional channel 8 with a pipe 11 for supplying air to the external chamber 2. The pipes for supplying air and removal of combustion products form a pipe-in-pipe heat exchanger in the device, in which the air is preheated. Finally, the air entering the combustion reaction is heated to the reaction temperatures in the combustion zone. The air is heated, passing through the manifold 5 (and manifold tubes 9), through the grill 3 and the wall 12, which are washed by the combustion products from the outer chamber 2 and the inner chamber 4. The air is distributed between the chambers. Part of the air goes to the grill, to the manifold and through the perforated wall. Air is consumed in the internal chamber for combustion of the fuel mass (pyrolysis and the formation of volatile combustible components, the burning of hardly volatile components and coke). Another part of the air is directed into the external chamber and is consumed for burning volatile combustible components - intermediate gaseous products coming from the inner chamber. To regulate the afterburning of intermediate gaseous products, a separate additional air supply channel 8 is used (with heating due to the heat of the external chamber). The fuel mass is loaded from above through the fuel loading hopper 1. As the fuel burns out, the fuel mass is lowered by gravity. When releasing the upper part of the hopper to a certain level, the fuel mass is periodically reloaded. The solid residue accumulates in the device and is periodically discharged through a separate pipe.

 The combustion zone of the fuel mass is located in the grating region. The maximum temperature is set in the lower part of the grate and gradually decreases towards its top and bunker. In the upper part of the lattice, volatile components and pyrolysis products are released. Volatile components - intermediate gaseous products through a perforated wall 12 go into the outer chamber 2, where they are burned to the final products. In the lower part of the lattice, hardly volatile and coking components burn, coke is formed and burns. Coke consists mainly of carbon, the oxidation rate of which is highly dependent on temperature and oxygen concentration. The use of a combustion chamber with a conical grate and a perforated wall provides reliable air access to the combustion zone (with self-distribution in the required quantities, with the required filtration rate). The taper of the wall and lattice gradually reduces the fuel mass layer to a minimum towards the end of coke burnout and thereby allows coke to be burned faster and easier. At the same time, part of the air, together with the coke combustion products, is spent on removing solid residue released from coke (through the annular gap between the grate and the perforated wall at the base of the grate). The grill is not designed to pass solid residue (ash and sand). The fuel mass and solid residue flow around the grill from top to bottom. Only air passes through the grill. The organization of the fuel mass combustion process is such that the products of reactions proceeding along the height of the combustion chamber move in two directions - up and down. Pyrolysis products move upward - volatile components and part of the non-volatile components (intermediate gaseous products) to burn in the free volume of the combustion chamber. The combustion products of the main part of the hardly volatile components and coke move downward, dragging sand which is again freed from coke into the free volume of the combustion chamber.

 To start the device, it is necessary to heat the combustion chamber with any fuel (for example, wood waste), and then load the working fuel mass.

Claims (7)

 1. A method of processing petroleum waste products with a high content of mineral deposits, in which waste together with solid fuel and air with some excess are fed to the combustion chamber for conducting combustion reactions in a continuous combustion process to the final gaseous products and solid mineral residue, the solid residue is continuously removed from reaction zone, characterized in that the combustion reaction of the waste and fuel is carried out in a gas-permeable volume, and the combustion reaction of the volatile combustible components of the waste and fuel is carried out in freedom the volume of the combustion chamber, which coaxially covers the volume with waste and fuel and communicates with it through a common gas-permeable, perforated wall.  2. The method according to p. 1, characterized in that the waste is mixed with solid fuel before loading into the combustion chamber to form a fuel mass.  3. The method according to p. 2, characterized in that as solid fuel use wood waste and any other types of solid fuel.  4. The method according to PP. 1-3, characterized in that the fuel mass is fed into the combustion chamber, and the solid residue is removed from it periodically.  5. The method according to p. 1, characterized in that the air is fed into the combustion chamber continuously in a quantity sufficient for complete combustion of the fuel mass and combustible gases and optionally with the possibility of controlling its supply.  6. The method according to PP. 1 and 5, characterized in that the air in the volume with the fuel mass is directed perpendicular to the flow of fuel mass from two opposite directions through the perforated wall and the conical grate in height.  7. The method according to PP. 1, 5 and 6, characterized in that the air when passing into the reaction zone is heated in the combustion chamber to the temperatures of the reactions occurring in it.