Can the garbage incinerator be equipped with a water wall?
2. Several common incinerator models
2 1 Foundation 1 Pulse Garbage Incinerator
Basic 1 pulse garbage incinerator is a patented technology for burning solid garbage invented by basic Sr of John N.. After continuous improvement and perfection, we now have 100 many independent technologies protected by patents in the United States and other countries in the world. This technology has been widely used to treat domestic waste, industrial waste, medical waste, sludge and waste rubber tires. The technology of building the master seat in the world uses waste incineration plants.
2, 1, 1 Main characteristics of pulse garbage incinerator
1) has a wide range of garbage disposal. Can deal with industrial waste, domestic waste, medical waste, waste rubber tires, etc. And the waste incinerator has not been pretreated before.
2) The incinerator with pulse throwing movable grate technology has self-cleaning function. On the one hand, the downward sloping design blows air from the road into the grate function; On the other hand, the air channel and air channel on the grate prevent blockage. Another grate suspension mechanism and power device are located outside the furnace, which is convenient for repair and maintenance.
3) The structure of the novel. As a whole grate, each block is suspended in a stepped grate structure, and the garbage trajectory is always in less contact with the surrounding water on the tank wall.
4) High combustion heat efficiency. The thermal efficiency of normal combustion is above 80%, and the waste water caused by incinerator ignition and occasional continuous rain is too large (above 60%). Therefore, when the temperature of the secondary combustion chamber is kept above 850℃, it is necessary to inject a small amount of fuel. In general, even if the boiled water is rubbish (50%), there is no need to add auxiliary fuel, such as coal or heavy oil.
5) Low operation and maintenance cost. Because there is no large and complicated mechanical transmission system outside the specially designed (such as full grate) furnace, the transmission parts of the whole transmission system are not exposed in the high-temperature furnace, and the accident rate of the incinerator is very low, saving maintenance costs. And the automation control level is higher, there are fewer operators and maintenance personnel, and the maintenance workload is reduced.
6) High reliability. In recent years, the failure rate of domestic equipment in incinerator operation is low.
7) High emission control level. Strictly control the combustion process of flue gas, secondary or tertiary reburning flue, and strictly control the combustion temperature, air ratio and residence time to reduce harmful gases such as hydrocarbons, carbon monoxide and nitrogen oxides. The test shows that when the HC content in1-10ppm is 2-3 PPM, and the level of nitrogen oxides is 35 PPM, the flue gas emission is lower than the European and American standards, especially the CO content in the flue gas emission in the system, which ensures that the residence time of the flue gas combustion system (above 850℃) is less than 2 seconds, and the dioxin emission is minimized, which fully meets the European and American emission standards.
2 1, 2 works
The garbage enters the drying bed of the incinerator, is automatically fed and dried, and then is sent to the first grate, the turbulent high-temperature pyrolysis furnace on the grate, and thrown by the pulse pneumatic device of the grate furnace. The garbage is thrown into the next grate, where polymer materials are pyrolyzed and other substances are burned. Of course, the automatic cleaning device does not discharge until it is finally burned into a ash pit. When combustion air is injected into the air holes on the grate and mixed with suspended air, garbage burns garbage. Volatiles and pyrolysis products enter the combustion chamber, unburned flue gas used in the third stage enters the second stage, the flue gas temperature passes through the heating surface of the steam boiler, and the flue gas is cooled and discharged.
2 1 3 incineration mechanism
Incinerate garbage in the furnace without any pretreatment. By automatically or manually controlling the waste entering the paper feeding device of the incinerator drying furnace to dry, pyrolyze and receive radiant heat in the main furnace, the waste water evaporates and the solid waste is easier to burn. At this stage (dry heat decomposition and gasification stage), the supply of controlled combustion air and oxygen is insufficient. In the part affected by high temperature radiation, the garbage begins to decompose chemically, and the drying temperature of the grate is controlled at about 500℃. 600℃, so it is the best thermal decomposition temperature and can achieve the best decomposition effect. Due to the induced draft fan, the residence time of the main evaporation platform in this part of gas is very short, only 1? For 2 seconds, due to insufficient oxygen supply, only 25% of hydrocarbons, residual ash from the main furnace, 15% of fixed carbon, residual ash from the furnace and the remaining 60% of volatile hydrocarbons entered the reburning chamber. After drying, volatile substances and combustible substances entering the first grate are decomposed and burned at high temperature in the furnace. The solid on the grate of the grate garbage incinerator is left on the left side, and the garbage is thrown into a new horizontal grate to continue burning under the strong mixing of air and throwing. A * * * incinerator with a row of six pulses. In this case, in the schematic diagram of Dawes furnace combustion principle, until the last grate is sprayed into the air for combustion, the completely burned garbage is discharged as a ash pit and an automatic cleaning device. The interface state, air, fuel particles and volatility of the reburning chamber of the whole incinerator are basically different. Due to the combustion intensity and required air volume of all levels of grates and garbage, the vibration frequency and swing amplitude of each grate cannot be completely controlled by computer, and the measurement accuracy is high. According to the different combustion characteristics and heat transfer modes, it can be divided into three stages: the first stage is arranged on the furnace membrane wall tube to receive the thermal radiation generated by fuel combustion. Combustion air is sent into the furnace from each grate fan at the lower part through nozzles to keep loose floating combustion airflow waste. This incinerator has the characteristics of grate and a small amount of fluidized bed. After a large amount of coking, the bottom of particles and unburned substances in flue gas are burned, and the second stage is the first stage when the temperature reaches 860℃. Then the flue gas from the combustion flue and quantitative high-speed air jet is introduced into dynamic mixed combustion, and the residual fire that is still not completely burned continues to enter the second stage, and then the intense combustion flue gas and excess air are mixed and burned, and the temperature reaches 1000℃. The main purpose of this process is not heat exchange. In the third stage, the temperature is controlled. At the inlet of the waste heat boiler, the flue gas with the temperature of℃ taken out from the outlet of economizer 190 is sent back to the waste heat boiler, and the high-temperature flue gas entering the waste heat boiler keeps the temperature of 760℃ for complete convection heat exchange. Then the superheater, economizer and air are preheated and dried lime and activated carbon are absorbed, and then the flue gas is discharged into the atmosphere from the chimney by the semi-dry flue gas treatment equipment and the induced draft fan described by the bag dust collector, and the lower part of the absorber is discharged.
2.2 Martin furnace mechanical grate furnace
Main characteristics of 2,21Martin furnace waste incinerator
Grates have high material requirements, high machining accuracy, smooth contact surface and small gap, and they are arranged in pairs. 1) Large-scale garbage disposal. Garbage is stacked in different areas, fermented in garbage storage pits, and mixed with garbage with uniform composition; 2) grate bar. Martin grate is made of high chromium heat-resistant and wear-resistant cast iron, which has better material properties. The unique grate ribs create a closed air duct structure, and the heat of the high-speed flowing main wind and the radiating fins are used to play the grate and the game, which effectively reduces the working temperature of the grate, thus prolonging the service life of the grate. 3) Operation to realize overall mechanization and automation; 4) Good incineration effect; 5) The smoke gas generated by the action is less, the tail gas is easy to handle, and the dioxin emission meets the environmental protection standards.
2, 2, 2 projects
The garbage enters the inclined downward grate through the hopper (the grate enters the drying area, in the burning area and the burnout area) and makes a big turn. Due to the grate between staggered scanning movements, the garbage pushes the garbage down through all areas on the grate in turn (garbage goes from one area to another) until it burns and is discharged from the electric furnace. Combustion-supporting air enters from the lower part of the grate and is mixed with garbage; The high-temperature flue gas passes through the heating surface of the boiler to generate hot steam, and at the same time, the flue gas has been cooled and finally discharged from the flue gas treatment equipment.
Incineration mechanism of 2,2,3
The garbage truck carrying garbage is unloaded into the garbage pit, and the garbage crane turns over the deleted garbage and mixes it in the partition pile. The reporter who opened the operating system refused to put the garbage with evenly mixed ingredients into the cellar for fermentation and storage, so as to avoid the fluctuation of the calorific value of garbage entering the furnace, which led to excessive temperature fluctuation in the furnace; Heap fermentation is an important experience to solve the problem of high moisture and low calorific value garbage incineration. Its precipitation mechanism is that part of water produces biogas, which not only increases the calorific value of garbage into the furnace, but also makes garbage easy to be ignited. After the fermented garbage is piled up for about two or three days, the crawler crane descends to the garbage hopper. The hopper and chute are closed from the furnace. In operation, at the joint of the charging door used for ignition, the charging door without garbage chute isolates the furnace from the outside and maintains the negative pressure of the furnace. Temperature curve: open the local charging door of garbage, and fill the whole trough device, garbage push grate burner and garbage grate furnace with falling garbage, as well as the thermal radiation in the sending process. Moreover, once it is blown dry by the wind, the water quickly evaporates and burns, and the furnace temperature gradually rises to the normal state. When the temperature in the furnace reaches 600℃, the outlet temperatures of the burner and garbage incinerator continue to rise and remain at about 850℃. The garbage grate dries, wasting the residual fire and unburned ash barrels in the three areas where combustible components are completely burned, and sending them to the slag remover. The slag crusher stores water and keeps the water level sealed to ensure that the negative pressure in the furnace pushes out the flame. The mechanical vibration conveyor belt of the ash slag in the cooling slag is sent to the ash storage pit and falls into the ash thrower, and the waste is burned into stable and harmless ash slag. The metal in the ash has the function of exposing the vibrating conveyor belt, which is convenient for hanging the vibrating conveyor separator for suction, collection and packaging reuse. In the process of garbage incineration, some tiny ash falls in the gap between the exhaust chambers of the furnace, which is called "ash leakage". In the timing system, the air chambers are opened in turn and fall into the lower valve, ash leakage discharge and ash tank in the wind. Under the action of indoor air pressure, one end of the ash tank is instantly opened through the slag crusher, air door and program air door connected with the ash leakage discharge system at the other end of the ethics office, and the leaked ash is finally blown to the federal slag crusher together. The ash storage cellar above the bridge grab crane is equipped with a grab to grab the ash, which will be collected in the ash storage pit and loaded into the landfill. Combustion-supporting air above the garbage storage pit is taken from (the garbage pit is sealed) and supplied by suction and pressure of two blowers, a primary steam heater and a secondary flue gas heater. The air temperature rises to about 250℃, and then it is divided into primary air, secondary air and primary air grid by heating to the public air chamber, and the throttle valve is adjusted to pass through the air chamber. Finally, the waste layer of the grate pipe is introduced into the furnace to get the best quantity. In front of the secondary air baffle, it needs to be injected into the furnace from above the combustion chamber, and two rows of nozzles are arched through the secondary air side air valve to disturb and supplement the oxygen of the combustion gas, so as to realize the oxygen after full combustion. The pollution caused by the garbage storage pit to the surrounding environment, the polluted dirty air is put into the furnace for high temperature treatment from the extracted combustion-supporting air, and the negative pressure of the garbage container pit is maintained to avoid escape. The first exhaust fan in the flue gas of high-temperature garbage combustion passes through the boiler in the first passage, which slows down the heat exchange speed of the long-term refractory zone at the lower part of the refractory material of the water wall of the passage, so that the flue gas temperature in this area is not lower than 850℃, and the maximum benefit of decomposing dioxins is achieved. Laying refractory belt can also avoid the corrosion of water wall at high temperature and the exposure of high temperature flue gas. The condensed slag in the flue gas covers the surfaces of the third channel and the quarter channel by convection heating, and carries out radiation heat transfer and heat exchange in the boiler outlet pipe through the second channel at an accelerated heat exchange rate, and then the flue gas temperature drops sharply from top to bottom to about 380℃. Secondly, it passes through the tubular flue gas heater in the fifth channel, and finally exchanges heat with air, and is cooled to about 270℃. The fourth channel has a bypass boiler flue and an adjusting baffle. In order to ensure that there is flue gas with set temperature at the entrance of electrostatic precipitator, the flue gas flow rate is adjusted through the fourth channel to control the flue gas temperature at the entrance of electrostatic precipitator. After the heat exchange of the flue gas treatment system of flue gas is completed.
2,3 LXRF vertical rotary kiln incinerator
LXRF series vertical rotary pyrolysis incinerator is the key equipment in the process of garbage incineration, which is jointly developed and manufactured by Shenzhen Dazu Solid Waste Treatment Equipment Co., Ltd. and the Department of Environmental Science and Engineering. This research project is a high-tech project in Shenzhen, which has been declared as the National 863 Plan. According to the Development of Wastewater Treatment Technology in Construction Industry, the incinerator is the development goal of the most advanced photothermal technology in the world, including the research and development of gasification and incineration technology in the Tenth Five-Year Plan and the 2006-2065,438+00 planning outline. This technology adopts a unique patented technology in furnace design.
Characteristics of 2,3,0 1 LXRF series vertical rotary pyrolysis incinerators;
High equipment utilization rate, low carbon ash, low excess air, low harmful gas emission and low calorific value of burning garbage.
1) advanced combustion mechanism;
2) Equipment manufacturing and operating costs;
3) Domestic garbage has strong adaptability, which is suitable for cities with low income, high calorific value and high water content in China, and does not classify garbage, especially for special garbage such as medical garbage and some industrial wastewater; BR/>；
4) garbage does not need pretreatment operation to realize full automation;
5) Incineration effect;
6) The flue gas is not easy to treat, and the emission of waste gas and dioxin is almost zero.
2, 3, 2 works
The cooling water pipe or refractory material is horizontal and slightly inclined along the furnace equipment in the rotary incinerator. Through the operation without stopping in the furnace, the furnace garbage is completely burned, and at the same time, the furnace is moved in the inclined direction until the exhausted furnace is discharged side by side.
Incineration mechanism
The furnace structure is divided into pyrolysis gasifier and secondary combustion chamber. The horizontal combustion distribution of pyrolysis gasifier is divided into drying part, pyrolysis part, combustion part, burnout part and cooling part from top to bottom. Part of the garbage entering the first section of the drying section in the pyrolysis gasifier rises and is decomposed into the pyrolysis gasification section of carbon monoxide, gaseous hydrocarbons and other combustible substances through thermal decomposition, forming flue gas drying and moisture evaporation; The mixed flue gas mixed flue gas is sucked into the second combustion chamber, and the residue after combustion (liquid tar, relatively pure carbon and garbage itself containing inorganic lime and inert substances, etc.) is pyrolyzed and gasified. ) is received at the temperature of complete combustion in the combustion zone until1100-1300℃, and its heat is used to provide energy required for pyrolysis in the flue and the drying section. After the residue, the residual fire generated by the combustion of the combustion part continues to burn until the cooling part is cooled by the primary air at the bottom (the residue is preheated by the primary air), and the broken slag is discharged out of the furnace through the mechanical extrusion of the grate. In the primary slag layer, in order to provide enough air for the combustion of oxygen in the combustion section, a large amount of oxygen in the upstream cracking section of the combustion zone is consumed by air, and pyrolysis gasification is formed under the condition of little oxygen or hypoxia. It can be seen that the garbage pyrolysis gasifier realizes the distributed energy level through pyrolysis: after the pyrolysis components are burned in the secondary combustion chamber, the pyrolysis residue and combustion garbage left by the pyrolysis gasifier are thermally decomposed, and the downward movement formed by gasification combustion is dynamically balanced. The furnace section of the feeding and slag discharge system reflects the continuous and stable operation of physical and chemical processes, thus ensuring the continuous and normal operation of the pyrolysis gasifier.
2.4 fluidized bed incinerator
2,4, 1 Function:
Compared with flue gas dust removal, the combustion control operation of full fluidized bed combustion boiler is huge and complicated, the operation cost is high, and the requirement for fuel particle size uniformity is higher, which requires the wear and tear of crushing device and quartz sand equipment and regular maintenance of equipment.
1) Use garbage, coal burning, special air distribution and garbage incinerator circulation to thoroughly clean and treat garbage;
2) The two separated materials can be separated and sent back in different weight ratios, so that the combustion is well controlled and the combustion efficiency is improved by more than 99%;
3) staged combustion and explosive staged low-temperature combustion (the flue gas temperature at the furnace outlet is 850℃) are adopted to effectively restrain and reduce the emission of sulfur dioxide and nitrogen oxides;
4) For garbage with high sulfur content and chlorine content, limestone and tailings washing methods are added to reduce the emission of SO2 and HCl, such as
5) The garbage is pumped into the hydrothermal treatment furnace from the sewage, and the secondary fan of the foul-smelling garbage storage box sucks and incinerates the incinerator. Garbage incineration helps to maintain clean air, groundwater and the surrounding atmospheric environment.
/& gt； 6) The cooling ash in the unique ash separation cooling device is suitable for the fluidized bed materials to be separated and returned to the fluidized bed.
2, 4, 2 projects
/& gt； Made of porous distribution plate of furnace, a large amount of quartz sand is added into the furnace, the quartz sand is heated to above 600℃, and the hot air blown into the bottom of the furnace is above 200℃, so that the hot sand boils, and then the garbage is put into it, which will soon dry up, and the unburned garbage with light fire and combustion ratio will continue to boil and burn, and the proportion of burned garbage will be large, and it will be cooled by water after falling to the bottom of the furnace.
set on fire
Combustion system mechanism
The boiler adopts gravity fluidized bed combustion mode and low-magnification fractionation cycle to separate the heat collector and materials from the furnace, and the system returns to the distributor at the bottom of the distributor and cools it with water. The water in the upper part of the furnace is also called dense-phase fluidized bed combustion chamber, and the lower part is inverted cone. The air distribution plate of the air chamber with special pressure under the hood is composed of water cooling pipes. The fuel of the main air that enters the dense phase from the air distribution plate cover of the pressure air chamber starts to burn, and the secondary air blown away by the material from the secondary air outlet of the air distribution plate blows to the furnace from the top of the bed. The ratio of the secondary air is about 7:3, which can be adjusted according to the change of the fuel and the operation situation, so as to achieve the purpose of complete combustion and control the generation of SO2 and nitrogen oxides.
In addition, the wind at that time made the back walls of several pipes enter the dense phase, respectively impacting garbage, coal and ash return, so that the garbage, coal and ash return were evenly dispersed into the compounds in the bed, and at the same time, the lower part of the dense phase area was strengthened.
In the upper area of dense-phase suspension section, in order to ensure that the residence time of flue gas in the furnace is more than 2 seconds, the materials carried by flue gas continue to burn in the expansion combustion furnace, and the heat released around the furnace returns to a part of dense-phase coarse materials due to cross-section expansion and collision with the wear-resistant layer at the top of flue gas suspension section, and only the fine materials in flue gas are blocked from the furnace to the partition plate. Separators of four rows of impact separators form condensed water slag pipes, which are arranged at the outlet of the separation device in the furnace. Because the flue gas in the furnace is separated by the thick part that affects the baffle material, it is separated from the flue gas passing through the recirculation combustion furnace below the collector cylinder of the separator, and then it is divided into two separators-through the lower exhaust cyclone separator of the superheater, and the further separated and collected fine materials are returned through the U-shaped return material. Dense phase, continue to circulate and burn. Superheaters are of pure convection type and are divided into two types. In order to prevent high temperature corrosion, they are arranged at the furnace outlet and behind the slag pipe. In order to ensure that the wall temperature does not exceed the temperature in the direction of flue gas flow, the steam temperature is adjusted within the range of 0-40℃ through desuperheaters on the surfaces of low-temperature superheater and high-temperature superheater, and at the same time, considering the characteristics of thermostats of desuperheaters on the surfaces of the two superheaters between the waste flue gas quantity, in order to prevent the wear of superheater tubes, except the wear of nickel-based alloy used. Two spiral case steel plate warm cyclone boilers have external steel structure, and the inertia separators behind the first two rows of thermal insulation superheater tubes are arranged in the superheater, which are made of thermal insulation and wear-resistant materials. The arrangement of the spiral case for separating the population ensures that the separation efficiency reaches 99.3%, and it bulges in the "U" of the non-mechanical valve check valve to ensure the smooth passage of materials and high temperature resistance, and can pass through the air preheater in the riser. It is arranged horizontally from top to bottom, and the spiral grooved tube of the air preheater tube is 5 1× 1.5, which is equipped with the inlet for wear and shell. In order to prevent low temperature corrosion, air. Anticorrosion of subordinate cordon tube. The feeding system is divided into two systems, which are arranged in front of the furnace and the movable equipment of the waste treatment system with sprocket feeding coal. Garbage is fed into the furnace through sprocket population, and seeds are evenly scattered on the bed. The coal feeding system consists of two positive pressure screws, and the single coal feeding amount is greater than the total coal feeding amount. The boiler combustion slag is connected to the cold slag separation device through the slag discharge port of the rear air distribution plate, and the continuous slag is cooled. When the cold slag separation device fails, it is necessary to isolate the artificial intermittent slag and the cyclone ash in the slag pipe urgently, subject to all or appropriate material layers. A part of the materials returning to the hearth are adjusted by the temperature of the gas at the outlet of the furnace to reduce the emission concentration of smoke and dust at the outlet of the boiler. Through the normal operation of the boiler and the furnace, a proper amount of bed material is added to maintain the sand mouth. For the height of the material layer, the auxiliary fuel-raw coal is added to ensure the normal heating and power generation of the thermal power plant. The garbage incinerator in Yuhang Thermal Power Plant has been running in good condition. The operation situation: the garbage incinerator runs stably, and all technical parameters and indicators meet the design requirements, ensuring the normal operation of the generator set. The longest continuous operation time exceeds 1 month, and the average garbage incineration amount is about 7 tons per hour, and the maximum can reach 1 1 ton per hour. Seasonal variation of composition and calorific value of garbage.
3. Summary
3, 1 waste pre-drying