CN2760405Y - Medical refuse burning system with combined use of rotary kiln and circulating fluid bed - Google Patents

Abstract

The utility model discloses a medical waste incineration system combined with a rotary kiln and a circulating fluidized bed. In the incineration chamber composed of the rotary kiln and the circulating fluidized bed, the rotary kiln plays the role of pyrolysis and gasification, and the circulating fluidized bed plays the role of burning embers. In the circulating fluidized bed, the residence time of the pyrolysis flue gas of the rotary kiln is 3-4 seconds, the residence time of solid combustibles is 40-60 minutes, the combustion efficiency is high, and the efficient burnout of medical waste is guaranteed. Add limestone in the circulating fluidized bed to suppress the emission of acid gases such as hydrogen chloride, prevent the corrosion of the incinerator and the tail flue, and have a long service life of the incineration system; use a high-temperature air preheater to heat the combustion-supporting air to above 500 °C In normal operation, there is no need to inject oil for combustion, reducing operating costs; the flue gas quenching device can cool the flue gas temperature from 550 ° C to 170 ° C within 0.5 seconds without contact between the flue gas and water, reducing the occurrence of dioxins Low temperature regeneration to prevent secondary pollution.

Description

The medical refuse burning system of rotary kiln and recirculating fluidized bed coupling

Technical field

The utility model relates to the medical refuse burning system of a kind of rotary kiln and recirculating fluidized bed coupling.

Background technology

Medical waste is meant the refuse with direct or indirect infection, toxicity and other harmfulness that medical and health organization produces in medical treatment, disease-prevention or healthcare and other correlated activations.The clinical waste contaminated environment, spreading disease, pose a health risk, endanger very greatly, is the primary refuse in " national hazardous waste register " 47 class hazardous wastes.The whole nation produced about 650,000 tons of clinical waste in 2002, and an average day generation is 1780 tons; Expect 2010, national clinical waste generation will reach more than 680,000 ton, and an average day generation reaches 1870 tons.For preventing that clinical waste from causing social danger, transmission; protection environment and guarantee health; the construction clinical waste centrally disposes engineering and carries out Whole Course Management; be safe storage and the disposal that realizes clinical waste; ensure the effective way of people ' s health and Environmental security; and in the construction that centrally disposes facility; the CIU of clean combustion, environment protection emission is particularly important, and exploitation efficiency of combustion height, pollutant can strictness reach " dangerous waste incineration pollution control criterion " (GB18484) CIU of emission request is extremely urgent.

Rotary kiln is present common a kind of medical refuse burning device, is derived from the rotary calciner of cement industry.Rotary kiln be one columniform simplified, inner lining refractory, slightly tilt to install, feed end is higher than discharging section, and motor drives cylindrical shell around the axle center unitary rotation by transmission mechanism, make medical waste mixing, pyrolytic gasification, catch fire, rubbish decomposes, is gasificated into fuel gas, therefore in slow rotation process, often as a combustion chamber of medical waste, a supporting dual firing chamber carries out after-flame simultaneously.But expose outlet end at present in the actual motion at rotary kiln, a large amount of using pyrolysis products are without burning discharge, and the effect of set traditional dual firing chamber all is used for the after-flame of gas, does not have further after-flame function for residual Jiao behind the rotary kiln pyrogenation or solid residue.Be difficult on the one hand to reach pyrolysis after heat burn decrement rate less than 5% target, cause secondary pollution on the other hand easily.

In addition, in the medical refuse burning system of rotary kiln and traditional dual firing chamber formation, because a large amount of chlorine-containing disinfectants and the plastic packaging bag that contain in the medical waste, make HCl content in the flue gas that medical refuse burning produces up to 1000ppm, caused the particularly etching problem of bootstrap system of back-end ductwork, under the serious situation, corrosion failure just appearred in back-end ductwork after two～three months, influenced the normal operation of system.

Recirculating fluidized bed is a kind of low pollution that is accepted with unanimity at electric power, environmental protection industry (epi) in recent years, efficient incineration technology, its ignition temperature is 850～950 ℃, the time of staying of solid particle in recirculating fluidized bed is long, efficiency of combustion is suitable for the high-efficient low polluting combustion of multiple different fuels such as coal, domestic waste, mud greater than 99%.Therefore, circulating fluidized bed technique is introduced medical refuse burning handle, the advantage of rotary kiln and recirculating fluidized bed is organically combined, form the medical waste treatment system that a kind of high-efficiency cleaning burns, have broad application prospects.

Summary of the invention

The purpose of this utility model is to provide the medical refuse burning system of a kind of rotary kiln and recirculating fluidized bed coupling.

Rotary kiln and recirculating fluidized bed are united the medical refuse burning system of formation, in CIU, elevating hopper is connected with batcher in turn, rotary kiln, rotary kiln and recirculating fluidized bed pyrolysis gas interface, the recirculating fluidized bed body, recirculating fluidized bed whirlwind separator, recirculating fluidized bed fluidized wind preheater, the flue gas quenching apparatus, semi-dry fume purifier, sack cleaner, air-introduced machine, chimney, the recirculating fluidized bed body is provided with the recirculating fluidized bed dilute-phase zone, the recirculating fluidized bed emulsion zone, slag-drip opening, pyrolysis wind and burnt wind air preheater and recirculating fluidized bed fluidized wind preheater also connect, the rotary kiln pyrogenation airduct of rotary kiln front end and pyrolysis wind and burnt wind air preheater upper end join, the rotary kiln rear end joins through rotary kiln and recirculating fluidized bed solid interface and recirculating fluidized bed body recirculating fluidized bed emulsion zone, recirculating fluidized bed whirlwind separator lower end is joined through recirculating fluidized bed loop back device and recirculating fluidized bed body recirculating fluidized bed emulsion zone, and recirculating fluidized bed body lower end joins through recirculating fluidized bed fluidisation airduct and recirculating fluidized bed fluidized wind preheater upper end.Recirculating fluidized bed fluidized wind preheater lower end and fluidisation blower fan join, and pyrolysis wind and burnt wind air preheater join with pyrolysis wind and burnt wind blower fan.

In service need not throw oil combustion-supporting normal for the utility model, reduces operating cost; Add the bed material of lime stone, can effectively suppress the discharging of the sour gas such as hydrogen chloride in the waste incineration, long service life as recirculating fluidized bed; The dual firing chamber that recirculating fluidized bed constitutes burns under 850～950 ℃ medium temperature condition, and the gentle time of staying of body heat hydrolysis products in recirculating fluidized bed of solid material is long, and the efficiency of combustion height has guaranteed the efficient after-flame of medical waste to prevent to cause secondary pollution.

Description of drawings

Accompanying drawing is the medical refuse burning system architecture schematic diagram of rotary kiln and recirculating fluidized bed coupling, among the figure: 1 elevating hopper, 2 batchers, 3 rotary kiln pyrogenation airducts, 4 rotary kilns, 5 rotary kilns and recirculating fluidized bed pyrolysis gas interface, 6 rotary kilns and recirculating fluidized bed solid interface, 7 recirculating fluidized beds burn airduct, 8 recirculating fluidized bed bodies, 9 recirculating fluidized bed whirlwind separators, 10 lime stones feed device, 11 recirculating fluidized bed fluidized wind preheaters, 12 recirculating fluidized bed fluidisation airducts, 13 pyrolysis wind and burnt wind air preheater, 14 recirculating fluidized bed loop back devices, 15 pyrolysis wind and burnt wind blower fan, 16 fluidized wind blower fans, 17 cooling water pumps, 18 flue gas quenching apparatus, 19 cooling towers, 20 semi-dry fume purifiers, 21 sack cleaners, 22 air-introduced machines, 23 chimneys, 24 recirculating fluidized bed dilute-phase zones, 25 recirculating fluidized bed emulsion zones, 26 slag-drip openings.

The specific embodiment

The utility model rotary kiln and recirculating fluidized bed are united the medical refuse burning chamber of formation, rotary kiln plays the refuse pyrolysis gasification, after rubbish feeds rotary kiln, in rotary kiln, rotatablely move slow forward, refuse pyrolysis under 500～600 ℃ hot blast effect, the combustible gas that produces after the pyrolysis is sent into the dilute-phase zone burning of recirculating fluidized bed top, and remaining solid matter is sent into the emulsion zone burning of recirculating fluidized bed bottom.Medical waste is tumbling motion in rotary kiln, material alternately is exposed in the hot flue gas, and the temperature of rotary kiln is relatively low, material is subjected to evenly heating slowly, moisture and volatile matter are separated out more even, have prevented the problem of combustible material detonations such as plastics when independent employing recirculating fluidized bed burns medical waste.

Recirculating fluidized bed plays the after-flame effect of gas phase and solid product after the pyrolysis in CIU, the bulk temperature of recirculating fluidized bed is between 850～1050 ℃, by classification air feed, oxygen-enriched combusting, strong reaction.After solid material enters recirculating fluidized bed, be the operation of fluidisation shape, its time of staying surpasses 40～60 minutes, has guaranteed burning of solid material, and the hot burn decrement rate of the lime-ash of discharge is less than 2%, far below the burning standard.

The fuel gas that rotary kiln pyrogenation comes out is after entering recirculating fluidized bed, gas contacts with 850～1050 ℃ of high concentration high temperature circulation solid particles of recirculating fluidized bed, the gas-solid two-phase is carried out strong heat exchange, the temperature of hot flue gas is elevated to rapidly more than 800 ℃, burning rapidly under the hyperoxia amount condition that the classification air feed feeds simultaneously, flue gas time of staying in recirculating fluidized bed surpasses 3～4 seconds, can make the abundant after-flame of fuel gas, effectively suppresses the generation of harmful substances such as dioxin.

Adding lime stone in recirculating fluidized bed expects as bed, the calcium oxide that lime stone pyrolysis under hot conditions produces can with the sour gas neutralization reactions such as hydrogen chloride that produce in the medical refuse burning, reduce the hydrogen chloride concentration of emission, avoided the etching problem of afterbody equipment.

The high-temperature flue gas that comes out from recirculating fluidized bed cools to 500 ℃ through air preheater earlier, and burning needed pyrolysis wind, fluidized wind and a burnt wind etc. are heated to more than 500 ℃, the high temperature combustion air has improved the ignition temperature level in the Burning Room, makes medical waste not need auxiliary fuel can keep burning.

The flue gas that comes out from the high temperature air preheater is cooled to 170 ℃ through the flue gas quenching apparatus, the flue gas chilling adopts the water pipe heat exchange type of cooling, flue gas flows outside pipe, water flows in pipe, not directly contact, avoided the generation and the after-treatment problem of sewage, the time of staying of flue gas in quenching apparatus reduced the low-temp recovery of dioxin in the flue gas less than 0.5 second.

As shown in drawings, rotary kiln and recirculating fluidized bed are united the Burning Room of formation, elevating hopper 1 is connected with batcher 2 in turn, rotary kiln 4, rotary kiln and recirculating fluidized bed pyrolysis gas interface 5, recirculating fluidized bed body 8, recirculating fluidized bed whirlwind separator 9, recirculating fluidized bed fluidized wind preheater 11, flue gas quenching apparatus 18, semi-dry fume purifier 20, sack cleaner 21, air-introduced machine 22, chimney 23, recirculating fluidized bed body 8 is provided with recirculating fluidized bed dilute-phase zone 24, recirculating fluidized bed emulsion zone 25, slag-drip opening 26, pyrolysis wind and burnt wind air preheater 13 and recirculating fluidized bed fluidized wind preheater 11 also connect, rotary kiln pyrogenation airduct 3 and the pyrolysis wind and burnt wind air preheater 13 upper ends of rotary kiln front end join, the rotary kiln rear end joins with recirculating fluidized bed body 8 recirculating fluidized bed emulsion zones through rotary kiln and recirculating fluidized bed solid interface 6, recirculating fluidized bed whirlwind separator 9 lower ends join through recirculating fluidized bed loop back device 14 and recirculating fluidized bed body 8 recirculating fluidized bed emulsion zones, and recirculating fluidized bed body 8 lower ends join through recirculating fluidized bed fluidisation airduct 12 and recirculating fluidized bed fluidized wind preheater 11 upper ends.Recirculating fluidized bed fluidized wind preheater 11 lower ends and fluidisation blower fan 16 join, and pyrolysis wind and burnt wind air preheater 13 join with pyrolysis wind and burnt wind blower fan 15.

Described rotary kiln and recirculating fluidized bed are united in the Burning Room of formation, rotary kiln plays the refuse pyrolysis gasification, recirculating fluidized bed works the effect of burning, the temperature of rotary kiln is 400～600 ℃, and the temperature of recirculating fluidized bed is 850～1050 ℃, the time of staying of flue gas behind the rotary kiln pyrogenation in recirculating fluidized bed is 3-4 second, and the time of staying of solid combustible is 40～60 minutes.In the flue gas quenching apparatus 18, flue gas is outside pipe, and cooling water flows in pipe.

Rubbish is connected to rotary kiln 4 by garbage feeding machine 2, pyrolysis under the hot blast effect of pyrolysis airduct 3, burning above 500 ℃, the combustible gas that burning discharges is sent into recirculating fluidized bed 8 bodies by rotary kiln and recirculating fluidized bed pyrolysis gas interface 5, recirculating fluidized bed dilute-phase zone 24 and cyclone separator 9 have constituted the dual firing chamber or the burning chamber of pyrolysis gas, add the hot blast of after-flame airduct 7 to guarantee sufficient oxygen supply in dilute-phase zone 24; The remaining solid matter of rotary kiln 4 pyrolysis is sent into recirculating fluidized bed 8 bodies by rotary kiln and recirculating fluidized bed solid interface 6, these solid matters are under the fluidization of recirculating fluidized bed fluidized wind 12, recirculating fluidized bed emulsion zone 25, dilute-phase zone 24, the burning space circulating combustion that cyclone separator 9 and loop back device 14 constitute, solid material following time of staying of hot environment of 850～950 ℃ above 30 minutes, guaranteed the abundant after-flame of solid material, the hot burn decrement rate of lime-ash of discharging burner hearths by big cinder notch 26 is less than 2%, and the lime-ash of discharge can directly use as building materials after removing metal.

The temperature range of recirculating fluidized bed dilute-phase zone 24 maintains 850～1050 ℃, the pyrolysis gas that rotary kiln 4 comes out time of staying of dilute-phase zone 24 above 2 seconds, time of staying of cyclone separator 9 above 3 seconds, the burning that has guaranteed gaseous products is complete, the discharging of organic pollutions such as dioxin is well below environmental protection standard, and 850～1050 ℃ reaction condition makes the discharging of NOx be lower than 50ppm.

Gas fume after burning is cooled to 550 ℃ through recirculating fluidized bed fluidized wind preheater 11 and pyrolysis wind and burnt wind air preheater 13, and combustion-supportingly be heated to 500 ℃ accordingly with pyrolysis wind and fluidized wind, both reduced flue-gas temperature, improved ignition temperature again, under normal operation, it is combustion-supporting not throw oil, has reduced operating cost.

Flue gas was reduced to 170 ℃ from 550 ℃ by quenching apparatus 18 in 0.5 second, prevent the low-temp recovery of dioxin.Discharging chimney 23 by semi-dry fume purifier 20, sack cleaner 21, air-introduced machine 22 then.

The CIU that adds dual firing chamber with general rotary kiln is different, and the utility model has provided the Burning Room structure of rotary kiln and recirculating fluidized bed coupling, makes solid material and the pyrolysis gas can completing combustion under 850～1050 ℃ temperature conditions.Recirculating fluidized bed adds lime stone (CaCO ₃) as the bed material, under hot conditions, CaCO ₃Resolve into CaO, carry out neutralization reaction with the hypochlorous acid of sterilization usefulness in the medical waste and the hydrogen chloride that the medical refuse burning process produces, both prevented the etching problem of equipment, prolong the life-span of equipment, reduced the hydrogen cloride concentration in the flue gas again, guaranteed the hydrogen chloride emission compliance, simultaneously, the source that has suppressed the chlorine of dioxin generation has reduced the concentration that dioxin discharges, and prevents that medical refuse burning from causing secondary pollution.

Claims (3)

1. A medical waste incineration system combined with a rotary kiln and a circulating fluidized bed, characterized in that the rotary kiln and the circulating fluidized bed are combined to form an incineration chamber, and the upper hopper (1) is sequentially connected with a feeder (2) , rotary kiln (4), rotary kiln and circulating fluidized bed pyrolysis gas interface (5), circulating fluidized bed body (8), circulating fluidized bed cyclone separator (9), circulating fluidized bed fluidized air preheater Heater (11), flue gas quenching device (18), semi-dry flue gas purification device (20), bag filter (21), induced draft fan (22), chimney (23), circulating fluidized bed body (8 ) is equipped with circulating fluidized bed dilute phase zone (24), circulating fluidized bed dense phase zone (25), slag outlet (26), pyrolysis air and ember air air preheater (13) and circulating fluidized bed The fluidization air preheater (11) is connected in parallel, the rotary kiln pyrolysis air pipe (3) at the front end of the rotary kiln is connected with the upper end of the pyrolysis air and ember air air preheater (13), and the rear end of the rotary kiln passes through the rotary kiln The solid interface (6) of the circulating fluidized bed is connected with the dense phase area (25) of the circulating fluidized bed body (8), and the lower end of the circulating fluidized bed cyclone separator (9) is sent back through the circulating fluidized bed The device (14) is connected to the circulating fluidized bed dense phase area of the circulating fluidized bed body (8), and the lower end of the circulating fluidized bed body (8) is connected to the circulating fluidized bed through the circulating fluidized bed fluidization air duct (12). The upper ends of the fluidized air preheater (11) are connected. The lower end of the circulating fluidized bed fluidized air preheater (11) is connected to the fluidization fan (16), and the pyrolysis air and ember air air preheater (13) is connected to the pyrolysis air and ember air fan (15). catch. 2. A medical waste incineration system combined with a rotary kiln and a circulating fluidized bed according to claim 1, wherein the temperature of the rotary kiln is The temperature of the circulating fluidized bed is 400-600°C, the temperature of the circulating fluidized bed is 850-1050°C, the residence time of the flue gas after pyrolysis in the rotary kiln in the circulating fluidized bed is 3-4 seconds, and the solid combustibles in the circulating fluidized bed The residence time is 40-60 minutes. 3. A medical waste incineration system combined with a rotary kiln and a circulating fluidized bed according to claim 1, characterized in that in the flue gas quenching device (18), the flue gas is outside the pipe, and the cooling water In the pipe, the residence time of flue gas in the quenching device is less than 0.5 seconds.