China's population is also a lot of garbage, garbage disposal of the two main ways to bury and incineration
Incineration of garbage can be power generation The disadvantage is that it pollutes the atmosphere.
Fujian private enterprise Fengquan Environmental Protection Equipment Co., Ltd. after 11 years of independent research and development, a leading international level of domestic waste incineration technology - "double-loop pyrolysis incineration" technology was born recently, for the first time in the zhuji city of zhejiang fengquan ripu The first time in zhuji city, zhejiang fengquan lipu harmless domestic waste treatment center application is successful. The technology does not need to add coal and oil and other auxiliary fuels, raw garbage does not need to be sorted, directly burned to produce efficient heat, clean emissions.
Waste incineration technology in foreign applications and development has been decades of history, the more mature type of furnace has a pulse-throwing grate incinerator, mechanical grate incinerator, fluidized bed incinerator, rotary incinerator and CAO incinerator, the following is a brief introduction to these types of furnace.
Mechanical grate incinerator
Working principle: garbage through the feed hopper into the grate tilted downward (grate is divided into drying area, combustion area, combustion area), due to the staggered movement of the grate between the garbage to the lower push the garbage, so that the garbage in turn through the grate on the various regions (garbage from one area into another, play a role in the big turn over), until the exhaustion of the combustion discharge Furnace chamber. The combustion air enters from the lower part of the grate and mixes with the garbage; the high temperature flue gas passes through the heated surface of the boiler to produce hot steam, and at the same time the flue gas is cooled, and finally the flue gas is processed by the flue gas treatment device and then discharged.
Characteristics: The material requirements and processing precision of the grate are high, and the contact surface between the grate and the grate is quite smooth, and the gap between the grate and the grate is quite small. In addition, the mechanical structure is complex, high damage rate, maintenance. Grate furnace cost and maintenance costs are high, making its popularization and application in China difficult.
Fluidized bed incinerator
Working principle: the furnace body is composed of porous distribution plate, add a large number of quartz sand in the furnace chamber, the quartz sand is heated to more than 600 ° C, and in the bottom of the furnace into the 200 ° C or more of the hot air, so that the hot sand boiled, and then into the garbage. The garbage boils together with the hot sand, and the garbage is quickly dried, caught on fire and burned. The unburnt garbage is light in specific gravity and continues to boil and burn, the burnt garbage is large in specific gravity and falls to the bottom of the furnace, after water cooling, the coarse slag and fine slag will be sent to the outside of the plant with the sorting equipment, and a small amount of medium slag and quartz sand will be sent back to the furnace through the lifting equipment to continue to be used.
Characteristics: fluidized bed combustion is sufficient, the furnace combustion control is better, but the amount of dust in the flue gas is large, the operation is complex, the operation cost is high, the fuel particle size uniformity requirements are high, the need for high-power crushing device, quartz sand on the equipment wear and tear is serious, and the equipment maintenance is large.
Rotary incinerator
Working principle: rotary incinerator is used to cool the water pipe or refractory materials along the furnace body arrangement, the furnace body is placed horizontally and slightly tilted. Through the non-stop operation of the furnace body, the garbage in the furnace body is fully combusted, and at the same time, it moves in the direction of the tilted furnace body until it is burned out and discharged from the furnace body.
Features: high equipment utilization, low carbon content in ash, low excess air, low harmful gas emissions. However, combustion is not easy to control, and it is difficult to burn when the calorific value of garbage is low.
CAO incinerator
Working principle: garbage transported to the storage pit, into the biochemical treatment tank, dehydration under the action of microorganisms, so that the natural organic matter (food waste, leaves, grass, etc.) decomposition of powder, other solids, including plastics and rubber, a class of synthetic organics and inorganic matter in the garbage can not be decomposed and pulverized. After screening, the waste that can not be pulverized into the incinerator first into the first combustion chamber (temperature of 600 ℃), the combustible gas generated into the second combustion chamber, non-combustible and non-pyrolysis of the components in the form of ash discharged in the first combustion chamber. The temperature of the second chamber is controlled at 860°C for combustion, and the high temperature flue gas heats the boiler to produce steam. The flue gas is treated and discharged to the atmosphere by the chimney. The metal glass will not be oxidized or melted in the first combustion chamber and can be sorted and recovered in the ash residue.
Characteristics: useful substances in the garbage can be recovered; but a single incinerator capacity is small, long processing time, the current maximum daily capacity of a single furnace to reach 150 tons, due to the flue gas in the 850 ℃ above the residence time is difficult to more than 1 second short, the flue gas in the dioxin content is high, environmental protection is difficult to meet the standards.
Pulse thrown grate incinerator
Working principle: the garbage is sent to the incinerator through the automatic feeding unit dry bed drying, and then sent to the first level of the grate, in the grate by the high-temperature volatilization, cracking, grate in the impulse of the air-powered device under the impetus of the throwing of the garbage thrown into the next level of the grate step by step, at this time, polymer cracking, and other substances for combustion. At this time, the polymers will be cracked and other substances will be burned. This will continue until it finally burns out and enters the ash pit, which will be discharged by the automatic slag removing device. The combustion air is injected into the grate by the air holes on the grate and mixes with the garbage to burn, and at the same time makes the garbage suspended in the air. The volatilized and cracked out material enters the second-stage combustion chamber for further cracking and combustion, and the unburned out flue gas enters the third-stage combustion chamber for complete combustion; the high-temperature flue gas passes through the heated surface of the boiler to heat up the steam, and at the same time, the flue gas is cooled and discharged.
The advantages are:
(1) Wide range of waste treatment Capable of treating industrial waste, domestic waste, hospital waste waste, discarded rubber tires and so on.
(2) High combustion efficiency Normal combustion efficiency is more than 80%, even if the water is very large domestic garbage, combustion efficiency is more than 70%.
(3) low operation and maintenance costs Due to the use of many special designs and a high level of automation control, so the operating staff is less (including the removal of ash and slag personnel, including a furnace only two people), the maintenance workload is also less.
(4) high reliability After nearly 20 years of operation shows that the incinerator failure rate is very low, the annual operation of more than 8,000 hours, the general utilization rate of more than 95%.
(5) high level of emission control Due to the use of two-stage flue gas re-combustion and advanced flue gas treatment equipment, so that the flue gas is adequately treated. After long-term testing, the CO content of flue gas emissions is 1-10 PPM, HC content is 2-3 PPM, and NOx content is 35 PPM, which is in full compliance with the European and American emission standards. Flue gas in the second and third combustion chamber combustion temperature up to 1000 ℃, and residence time of more than 2 seconds, can make the basic decomposition of dioxin, the flue gas dioxin content of 0.04 ng/m3, far lower than the European and American standards of 0.1 ng/m3.
(6) the grate in the compressed air under the blowing, has a self-cleaning function.