Can a water-cooled wall be set up in the waste incinerator?

At present, outside the municipal waste disposal mainly using sanitary landfill, high temperature composting and incineration and other three treatment methods. Sanitary landfill, high-temperature composting secondary environmental pollution, due to the large area, the proportion of its use is less and less. But harmless to humans, resources, reduce to the final disposal of incineration more and more to get a high-speed development, urban household waste incineration treatment technology has a wide range of applications. Incineration technology is characterized by significant: volume reduction, high degree of harmlessness; incineration facilities, small footprint, no secondary pollution of the surrounding environment, the effect of high calorific value of garbage to reach a certain scale, you can also take advantage of the rest of the heat to generate electricity or heating. Incineration to maximize the fastest speed of solid waste-free? Harmful, stabilization, reduction, treatment systems and large equipment equipped with heat recovery and utilization, waste to treasure, waste energy recovery, become the mainstream environmental waste treatment. Incineration technology is moving toward the direction of high efficiency, energy saving, low cost, low pollution. Therefore, the calorific value of urban waste in economically developed cities, so the use of advanced incineration technology to deal with municipal solid waste is the best choice and investment. Waste incineration treatment technology and equipment have matured. Our mainstream waste treatment incinerators: Throwing motion Basic1 pulsating waste incinerator, Martin Furnace Reciprocating Mechanical Grate Furnace, LXRF Series Vertical Rotary Kiln Incinerator, Fluidized Bed Incinerator. And other supporting power or heat production technology and equipment, such as: waste heat boilers, steam turbines, flue gas desulphurization, water treatment systems, electrical and automation control, basically very similar, but also very mature. Analysis of common types of waste treatment incinerators within China.

2, several common incinerator models

2,1 Basic1 Pulse Throwing role of the waste incinerator

Basic1 Pulse Throwing garbage incinerator invented by the U.S. U.S. John N. Basic Sr incineration of solid waste patented technology, specifically for. After continuous improvement, perfect, now has more than one hundred independent U.S. and the rest of the world's patent-protected technology, the technology has been widely used to deal with domestic garbage, industrial waste, medical and health care waste, sludge and waste rubber tires in the world to build a total seat using the garbage incineration plant technology.

2,1,1 The main features of pulse-throwing garbage incinerator

1) Processing garbage in a wide range. Able to deal with industrial waste, domestic garbage, medical waste, waste rubber tires, etc., and before without any pretreatment garbage incinerator.

2) Pulse throwing movable grate technology incinerator, self-cleaning function. Downward sloping design blowing into the air on the one hand from the road blowing grate function; on the other hand, the grate on the air channel, the air channel to prevent clogging. Another grate suspension mechanism and power plant are set outside the furnace, easy to repair and maintenance.

3) The structure of the grate novel. Each block as a whole grate suspension stepped structure of the grate, the garbage track is always less contact with the surrounding water in the groove wall.

4) High combustion thermal efficiency. Normal combustion thermal efficiency of more than 80%, incinerator ignition and occasional continuity of rain caused by wastewater when too large (more than 60%), so the secondary combustion chamber is maintained at a temperature of more than 850 ° C. It needs to be injected into a small amount of fuel generated by the combustion of the outside, under normal circumstances, even if it is burning water is very garbage (50%), but does not require the addition of auxiliary fuels, such as coal or heavy fuel oil.

5) Low operation and maintenance costs. Due to the special design (such as full grate) outside the furnace, there is no large and complex mechanical transmission system, the entire transmission system is designed to drive parts are not exposed to high temperature furnace, incinerator accident rate is very low maintenance, saving maintenance costs. As well as a higher level of automation control, operation and maintenance personnel less, reducing maintenance workload.

6) High reliability. Domestic equipment in recent years, the incinerator running a low failure rate.

7) High emission control level. Strict control of the flue gas, two, three re-combustion flue combustion process, more strictly controlled? Control combustion temperature, the amount of air ratio and residence time to reduce the production of harmful gases such as hydrocarbons, carbon monoxide and nitrogen oxides. Tested from 1-10 PPM HC content 2-3 PPM NOx level 35 PPM, the flue gas emissions are lower than the standards in the U.S. and Europe, especially the CO content in the flue gas emissions in the system to ensure that in the flue gas combustion system (850 ℃ above the temperature) stays less than 2 seconds, the dioxin emissions are to the minimum to fully satisfy the European and U.S. emission standards.

2,1,2 works

The garbage enters the incinerator's drying bed, there is an automatic feeder dry, and then sent to the first stage of the grate, the grate on the turbulent high-temperature pyrolysis furnace, the grate furnace impulse air power unit driven by a throw, the garbage is thrown into the next step-by-step grate, the polymer material pyrolysis, the combustion of the other substances. Of course, until finally burned into the ash pit, which is discharged by the automatic cleaning device. Combustion air is injected into the air holes on the grate and entrapped in the air when the garbage is suspended in the garbage incineration. The volatile and pyrolyzed material enters the combustion chamber, further pyrolysis and combustion of the fully combusted combustion chamber for the third stage of the unburned flue gas enters the temperature of the flue gas through the heated steam boiler to heat the surface of the second stage, while the flue gas is heated by the heated steam boiler to heat the surface of the second stage. Surface of the second stage, while the flue gas cooled and discharged.

2,1,3 Incineration Mechanism

The incoming waste is incinerated without any pretreatment. Through automatic or manual control into the incinerator drying furnace paper feeder waste waste bent drying, pyrolysis, and receiving radiant heat in the main furnace, in the drying grate, wastewater evaporation, solid waste, easier burner. This stage of combustion (dry pyrolysis and gasification section) is controlled by an insufficient amount of air and oxygen supply. In the part of the waste affected by high temperature radiation, begins to chemically decompose, in which polymer hydrocarbons and combustible materials such as carbon monoxide volatilize out of the part of the grate, the drying temperature of the grate is controlled at about 500 ° C to 600 ° C, and therefore is the best thermal decomposition temperature, you can achieve optimal decomposition, due to the induced fan, the gas in this part of the main evaporation table within the residence time is very short, only 1 to 2 seconds, due to the oxygen supply is not enough. As the oxygen supply is insufficient, only 25% of the hydrocarbons are burned in the main furnace as embers, 15% of the fixed carbon is burned in the furnace as embers, while the remaining 60% of the volatile hydrocarbons enter the recombustion chamber. After drying, into the first grate of volatile and combustible substances in the furnace bed at high temperatures through thermal decomposition, combustion. Grate waste incinerator grate on the solid left to stay on the left side, in the violent mixing of air and thrown, the garbage thrown into a new level of the grate to continue combustion. There are six incineration grates in a ****. In this case, Dawes Furnace combustion principle schematic, until the last grate, sprayed into the air when the combustion is completely burned waste for the ash pit and automatic cleaning device discharge. The entire incinerator re-combustion chamber interface state, air, fuel particles, volatile basically incomplete combustion state is not the same, due to all levels of grate and the amount of waste combustion combustion intensity and the amount of air required, so each grate vibration frequency and swing amplitude can not be fully controlled by the computer, high measurement accuracy. According to the different combustion characteristics and heat transfer mode can be divided into three stages: the first stage is arranged in the furnace membrane wall tube to receive heat radiation generated by fuel combustion. The combustion air from the lower part of each grate fan, through the nozzle into the furnace to maintain a loose floating combustion airflow waste, which incinerators are grate characteristics, there is a small amount of fluidized bed characteristics. After much coke, the flue gas particles in the bottom of the furnace and the combustion of unburned material, the temperature reaches 860 ° C in the second stage is in the first stage, and then with the combustion of the flue and quantitative high-velocity air jets of flue gas is introduced into the vibrant mixed combustion, still incompletely combusted embers continue to enter the second stage, and then intense combustion of the flue gas and the excess of air mixed combustion, the temperature reaches 1,000 ° C The main purpose of this process without heat exchange is to raise the temperature of the flue gas to accelerate the decomposition of harmful substances in the flue gas before mixing; the third stage to control the temperature at the inlet of the waste heat boiler, the flue gas from the exit of the economizer 190 ° C flue gas is fed back to the waste heat boiler, the flue gas into the waste heat boiler, the flue gas temperature is maintained at 760 ° C under the high-temperature flue gas combustion with complete convection heat transfer, and then after the superheater After the superheater, economizer, air preheating drying lime and activated carbon absorption treatment, and then through the semi-dry flue gas treatment equipment and bag vacuum cleaner depicted out of the induced draft fan from the chimney discharge into the atmosphere, the absorber lower discharge of fly ash and lime mixture by the ash removal device.

2,2 Martin Furnace mechanical grate furnace

2,2,1 Martin Furnace waste incinerator main features

grate material requirements, and requires high machining accuracy, the requirements of the contact surface is also quite smooth, quite a small gap between the rows and rows of the grate, grate. 1) Wide range of processing garbage. Partitioned stacks of garbage, garbage storage cellar fermentation, turning and mixing the garbage of uniform composition; 2) Grate type grate. Martin grate with high chromium heat-resistant, wear-resistant cast iron, material performance is better, the unique grate ribs create a closed air duct structure, the use of high-speed flow of the main air heat, grate to go, play in the cooling fins, effectively reducing the working temperature of the grate, thus prolonging the service life of the grate 3) operation to achieve the whole process of mechanization and automation; 4) incineration effect is good; 5) the role of the smoke produced by the less gas The exhaust is easy to handle, dioxin emissions in line with environmental standards.

,2,2,2 works

The garbage enters the inclined downward grate through the feeding hopper (the grate enters the drying area, in the combustion area and the combustion area) plays a great turn around due to the interlaced scanning motion between the grate, the garbage pushes the garbage downward through the various areas on the grate in order (the garbage passes from one area to the other) until burns the discharging furnace. Combustion air enters from the lower part of the grate and mixes with the garbage; high-temperature flue gas passes through the heating surfaces of the boiler to produce hot steam, while the flue gas has been cooled and finally discharged after being treated by the flue gas treatment equipment.

2,2,3 incineration mechanism

Transportation of garbage garbage trucks, unloaded into the garbage pool garbage crane will remove the garbage mixing, mixing partition stacks, the operating system opens the program of the reporter refused to the storage cellar fermentation mixing mixing homogeneous composition of the garbage, to avoid fluctuations in the calorific value of the garbage into the furnace, resulting in excessive fluctuations in the temperature inside the furnace; Stacks of fermentation is the solution to the high moisture, low calorific value of the garbage incineration of the important The experience of its precipitation mechanism, part of the water, produces biogas, which both raises the calorific value of the waste into the furnace and allows the waste to ignite easily. After about two to three days of fermenting the garbage stack, a crane climbs a net to lower the garbage into a hopper. The hopper and chute are removed from the furnace at the junction of the material gate used for ignition shutdown during operation, and the material gate without the trash chute allows the furnace to be separated from the outside world in order to maintain negative furnace pressure. Heating curve, put the garbage when the loading door is open, along the trough of the feeding platform and the falling garbage filled with the entire trough material device, garbage push grate burner, garbage grate furnace, send the process of heat radiation, and once the wind blowing dry, the moisture evaporates rapidly, and combustion, the furnace temperature gradually rises to normal, when the temperature of the furnace reaches 600 ℃, the exit of the burner, the temperature of the garbage incinerator continues to rise, and remain at about 850 ℃. Waste grate to turn dry, waste combustible components of complete combustion of the three regions of combustion and combustion of the residual ashes of non-combustible ash drum sent to fall into the slag machine, slag crusher to store water, maintain the water level plays a water seal to ensure stability of the furnace in the negative pressure to launch the flame and cooling of the ash in the slag in the furnace machine of the vibrating conveyor belt to send to the ash storage pit in the pitching of the ash machine into the ash storage pit fall, waste incineration becomes stable, harmless ash. The metal in the ash has a role in the vibrating conveyor belt exposed to facilitate the vibrating conveyor separator hanging above the suction, pooling and packaging for reuse. During the waste incineration process, some fine ash falls down the gap between the grate air chambers, these are called "leakage ash gray timing system, sequentially open the air chambers in the wind falls into the valve below the leakage ash discharge, leakage ash ash canisters, the air pressure inside the room is connected to the other end of the ash chute through a slag machine, damper and public **** ethical office! Leakage ash discharge system of the program damper instantaneous opening, will leakage ash blowing method Federal Reserve slag machine finally, together with the ash discharge. Bridge grab crane above the ash of the storage cellar equipped with a grab grab will be pooled in the ash storage pit ash, loading trucks out of the landfill. Trash storage pit above the air for combustion is taken from (trash pool sealed), two blowers for suction and pressure feed, the first stage steam heater, said second stage flue gas heater, the temperature of the air rises to about 250 ° C, and then through the heated to the public **** air chamber is divided into primary air and secondary air and primary air under the grate, adjusted throttle through the air chamber, and finally, through the castor pipe trash layer Introduced into the furnace, the amount of air to obtain optimal air distribution waste incineration; secondary air damper before the required from above the combustion chamber, the arch in two rows of nozzles sprayed into the furnace through the secondary air side dampers duct by disturbing and replenishing the combustion gases of oxygen to achieve full combustion after oxygen. Waste storage pit caused by the pollution of the surrounding environment from the extraction of air for combustion, the air will be contaminated with foul odors into the furnace for high-temperature treatment, and to maintain the state of the waste container pit negative pressure to avoid the escape. High-temperature waste combustion flue gas in the first inhalation fan through the boiler of the first channel, the lower part of the channel water wall refractory material is laid with a long-term fusible strip of heat exchange is slowed down, so the flue gas temperature in this area is maintained at not less than 850 ° C, and the decomposition of dioxin-like substances of the greatest practical benefit. Laying the fusible link also avoids the corrosion of the water wall in the high temperature to be exposed to the high temperature flue gas. The condensate residue in the flue gas to the third channel with convection heating surface covering and quarter channel to accelerate the heat exchange rate in the boiler's exit tube through the second channel of radiation heat transfer, heat exchange, and then from the top down to the temperature of the flue gas is reduced to about 380 ℃. Next through the tubular flue gas heater of the fifth channel of the arrangement, it is finally cooled to about 270°C by heat exchange with air. The fourth channel has a bypass boiler flue and an adjustment baffle in order to ensure stabilization of the temperature of the flue gas at a set temperature value at the inlet of the electrostatic precipitator by adjusting the amount of flue gas flowing through the fourth channel to control the inlet temperature of the smoke of the electrostatic precipitator. The heat exchange of the flue gas of the flue gas treatment system is completed.

2,3 LXRF Vertical Rotary Kiln Incinerator

The LXRF Series Vertical Rotary Pyrolysis Incinerator is jointly researched and developed by Shenzhen Daqi Solid Waste Treatment Equipment Co. The research project for the Shenzhen high-tech projects, and has declared the national 863 program. Ministry of Construction, the construction of industrial wastewater treatment technology development, "incinerator is the world's most advanced photothermal technology development goals, including gasification incineration technology in the Tenth Five-Year Plan and the Outline of the 2010 Planning 2006-2010 research and development of this technology, the design of the furnace body using unique patented technology.

2,3,1 LXRF Series Vertical Rotary Pyrolysis Incinerator Characteristics:

High equipment utilization, low carbon content ash, low excess air, low emission of harmful gases, combustion of garbage with low calorific value of the difficulty.

1) advanced combustion mechanism;

2) equipment manufacturing, operating costs;

3) domestic garbage, adaptable, suitable for China's urban low-income calorific value, high moisture, do not sort the garbage, especially for medical waste and other special garbage, part of the industrial wastewater; BR / & gt;

4) the garbage does not require pre-treatment operations. Realize the full automation;

5) incineration effect;

6) flue gas is not easy to deal with, exhaust gas, dioxin emissions are almost zero.

2,3,2 works

Along the rotary incinerator furnace equipment cooling water pipe or refractory material, the furnace is horizontal and slightly tilted, through the non-stop operation in the furnace body, so that the furnace waste full combustion, the furnace tilted in the direction of the movement until the burnout out of the furnace body and row at the same time.

2,3,3 Incineration mechanism

The furnace structure is divided into pyrolysis gasifier and secondary combustion chamber of pyrolysis gasifier combustion level distribution is divided into drying section pyrolysis section, combustion section, combustion ash section and cooling from the top to the bottom. Garbage enters the pyrolysis gasifier in the drying section of the first segment of the first section rises through thermal decomposition, decomposing into carbon monoxide, gaseous hydrocarbons and other combustible materials in the pyrolysis and gasification section and forms a flue gas which dries out and evaporates the moisture; mixed flue gas mixed flue gas is sucked into the second combustion chamber where the pyrolysis and gasification of the combusted residue (liquid tars, relatively pure carbon, and the garbage itself containing inorganic lime and inert materials, etc.) are received. inert substances, etc.) is received into the combustion zone at a temperature of full combustion, to 110 to 130°C, and its heat is used to provide the energy required for pyrolysis in the section and drying section. After the residue, the resulting combustion section of the combustion of the combustion section continues to burn to the cooling section from the bottom of the primary air-cooled (residue preheating primary air), through the mechanical extrusion of the castor, crushing the slag system discharged out of the furnace pyrolysis gasifier. Primary residue layer to provide sufficient combustion oxygen to the combustion section of the air through the air consumes a large amount of oxygen in the combustion zone in the upstream linkage cracking section, and the formation of the reaction occurs with less oxygen or anoxic conditions of pyrolysis and gasification. The waste pyrolysis gasifier can be seen by the dynamic equilibrium of thermal solutions to achieve the distribution of energy levels: cracking components into the secondary combustion chamber for incineration, combustion of the waste thermal decomposition, gasification and combustion to form a downward-directed movement of the pyrolysis residue left behind in the pyrolysis gasifier. The feed and slag discharge system of the furnace section reflects the physical and chemical processes also stabilized by continuous stable operation in order to ensure continuous normal operation of the pyrolysis gasifier.

2,4 Fluidized Bed Incinerator

2,4,1 Characteristics:

Fully fluidized bed combustion boiler combustion control than flue gas de-dusting large and complex operation, high operating costs, higher fuel particle size uniformity requirements, the need for crushing plant, wear and tear on the quartz sand equipment and the need for regular maintenance of the equipment.

1) Using garbage, coal, special cloth wind, garbage incinerator cycle, thoroughly clean treatment of garbage;

2) can be arranged to separate the two separation materials and return a different weight ratio well controlled combustion, improve the combustion efficiency of more than 99%;

3) the use of graded combustion and explosion grading low-temperature combustion (furnace exit flue gas temperature of 850 ℃), effectively suppressing and reducing the emission of CO2, CO2, CO2, CO2 and CO2. Effectively inhibit and reduce the emissions of sulfur dioxide and nitrogen oxides;

4) For high sulfur and chlorine-containing MSW, adding limestone and tail scrubbing methods to reduce SO2 and HCl emissions, such as

5) Waste water from sewage is pumped into the hydrothermal furnace, the odor of the waste storage tanks, the secondary fan suction combustion incinerator, waste incineration combustion air, groundwater and surrounding The atmosphere is cleaned to maintain

/> 6) A unique ash separation cooling device in the cooled ash suitable for fluidized bed material is sorted and fed back into the fluidized bed.

2,4,2 Engineering

/> Furnace made of porous distributor plate to which a large amount of ? of quartz sand, quartz sand heated to more than 600 ℃, and in the bottom of the furnace drummed into the hot air at 200 ℃ or more, so that the hot sand boiling up, and then invested in garbage, garbage hot sand boiling, garbage will soon dry out, fire, burning the proportion of lighter unburned garbage, continue to boil combustion, burning a larger proportion of the garbage, down to the bottom of the furnace after the water cooling coarse slag, slag micronized powder sorting equipment outside of the plant, the A small amount of medium slag and quartz sand through the lifting equipment sent back to the furnace to continue to use.

2,4,3 Incineration

The mechanism of the combustion system

The boiler uses a gravity-fluidized bed combustion mode and a low-magnification fractionation cycle by the furnace, in which the material separates the collector and the material, and the system is returned to the return for the three-part reclaimer configured in the bottom of the air distribution plate, which is cooled by the water. The upper part of the furnace chamber has a membrane of water, also known as a dense-phase fluidized bed combustion chamber, with an inverted conical lower part. Hood a special form of pressure composed of air chamber air distribution plate by a water-cooled tube, by the pressure of the air chamber air distribution plate hood into the main air of the dense phase of the fuel to start combustion, and the material is blown away from the air distribution plate of the secondary air outlet anyone to the furnace from the upper part of the bed of the secondary air, the ratio of the secondary air of about 7:3 and can be adjusted according to the need for fuel changes and operation can be achieved! The purpose of complete combustion, but also control of SO2 generation amount of nitrogen oxides.

In addition, the wind by then leads to the back wall of several pieces of pipes into the dense phase, respectively hit the trash, coal and return material ash, so that the trash, coal and return material ash and other materials evenly dispersed to the bed of compounds go, while strengthening the lower part of the disturbance of the dense phase zone.

The upper area of the dense-phase suspension section, in order to ensure that the residence time of the flue gas in the furnace for more than 2 seconds, has been enlarged to combust the furnace portion of the flue gas carrying the material to continue combustion, exothermic around the furnace, due to the cross-section is enlarged, and the flue gas suspension section collides with the roof of the anti-abrasive layer, the return of the coarse material into the dense-phase portion of the flue gas only carries the fine-grained material far away from the furnace into the bulkhead. Four rows of impact separator separators, consisting of condensate slag pipes, are set in the furnace at the outlet of the separator device, as the flue gas in the furnace through an impact partition the thicker portion of the material is separated out, below the separator collection drum of the recirculation combustion furnace returns after the passage of the finer material through the flue gas is separated out, and is then divided into two separators through the superheater - a further cyclone separator with lower exhaust gas The finer material is separated and collected through a U-shaped return to the area of the return. The dense phase continues the combustion cycle. The superheater is purely convective and is divided into two types, which are arranged to prevent high temperature corrosion at the outlet of the furnace chamber, behind the condensate slag pipe. In order to ensure that the wall temperature does not exceed that temperature along the flow direction of the flue gas, and then by the low-temperature superheater and high-temperature superheater surface there is a desuperheater to regulate the steam temperature in the range of 0-40 ℃, taking into account the incineration of the volume of waste flue gas between the two superheater surface desuperheater the thermostat characteristics In order to prevent wear and tear of the superheater tubes in addition to use of nickel-plated base alloy. Cyclone boiler with two shells of steel plate temperature, external steel structure, internal laying of insulated superheater tubes in the first two rows after the inertial separator arrangement in the superheater, insulated with wear-resistant materials. Separation of the population of worm shell arrangement to ensure that the separation efficiency reached 99.3%, non-mechanical valve check valve "U" feeding to ensure that the material passage is smooth and can withstand high temperatures, wear-resistant vertical tube in the air preheater, the upper and lower horizontal arrangement of the air preheater tubes helical groove tube 51 × 1.5, equipped with abrasion and shell of the Inlet, in order to prevent low-temperature corrosion, air preheater and back-bonding. Slave Cowden tube corrosion protection. The feed system is divided into two systems are configured at the front of the furnace of refuse and coal with a sprocket feed of the waste disposal system of mobile equipment in order that the refuse is fed into the furnace through the sprocket population, sown evenly scattered on the bed broadcasting refused to wind blowing Stoke Coal feed system consists of two positive pressure spirals consisting of a single amount of coal is greater than the amount of fully loaded coal. Boiler combustion slag through the rear side of the air distribution plate slag outlet connected to the cold slag separation device, continuous slag after cooling, cold slag separation equipment failure, the use of emergency to put the manual intermittent slag, slag slag tube cyclone ash isolation, all or maintain the appropriate layer of material shall prevail. Part of the material returned to the furnace bed temperature regulation, the temperature of the furnace exit gas device to reduce the boiler exit smoke? Dust emission concentration through the boiler, the normal operation of the furnace plus the appropriate amount of bed material to maintain the sand outlet. The height of the material layer, adding auxiliary fuel - raw coal to ensure normal heat and power generation of the thermal power plant. Yuhang Thermal Power Plant's waste incinerator has been running, running well, its operation: the waste incinerator, stable operation, the technical parameters and indicators have reached the design requirements to ensure that the normal operation of the generating unit, the longest continuous operation time of more than 1 month, an average of about 7 tons of waste incineration per hour, the largest number of up to 11?t / h, the composition of the waste, the calorific value of the seasonal changes and adaptability.

3, summary

3,1 Waste pre-drying