CN102643007A - Drying device for sewage sludge - Google Patents

Abstract

The invention discloses a drying device for sewage sludge, comprising a fluidized bed reactor, a condensing heat exchanger, a boiler air preheater, a water pump, a blower and a booster fan. a heat transfer pipe is arranged on the outer surface of the fluidized bed reactor, the fluidized bed reactor comprises a feeding device, an overflow port and an air chamber, the feeding device and the overflow port are arranged in the middle part of the fluidized bed reactor, and the air chamber is positioned in the bottom of the fluidized bed reactor; the inlet end of the heat transfer pipe is connected with a new steam pipeline from a boiler, and the outlet end of the heat transfer pipe is connected with a pipeline leading to the boiler; one end of the condensing heat exchanger is connected with the upper part of the fluidized bed reactor, and the other end is connected with the air chamber of the fluidized bed reactor through the boiler air prehater and the booster fan; and the blower is connected with the condensing heat exchanger. According to the drying device for sewage sludge, the energy consumption in the drying process is reduced, energy sources are saved, and the emission of greenhouse gas is reduced, the drying device is not only applicable to drying sewage sludge and but is also applicable to drying common sludge.

Description

A kind of sewage sludge is used drying installation

Technical field

The present invention relates to the dry materials technical field, the drying of high-moisture sewage sludge particularly, specifically a kind of sewage sludge is used drying installation.

Background technology

In the municipal sewage treatment process, can produce a large amount of sewage sludges.Moisture content in the sewage sludge is very high, and after processed, the moisture of dewatered sludge is usually above 70%, sometimes even up to more than 80%.Sewage sludge is a kind of solid waste resource that contains flammable organic substance.Reason such as low owing to the thermal value of sewage sludge, that moisture content change is big, sewage sludge is difficult to directly lighted or keep stable burning, also is difficult to direct pyrolysis and produces alternative fuel oil.At present, sewage sludge just nearly all recycles directly landfill, has caused the waste of limited waste material on the one hand; Not only floor space is big for landfill on the other hand, and the methane gas that produces has aggravated topsoil and Greenhouse effect.Therefore, rationally recycling sewage sludge has energy-conservation and the environmental protection double meaning.

At present, for the research and the utilization of sewage sludge resource utilization and energy, mainly aspect following two: mud acts as a fuel or auxiliary fuel, adopts various combustion technologies, reclaims heat; Adopt physics and chemical process with drying sludge, produce alternative fuel oil.

Sewage sludge can be used to do fuel or auxiliary fuel owing to contain combustiblecomponents, practices thrift the part high-grade fuel, often is used to boiler oil, produces hot water or steam.But this technical requirements master combustion equipment must reach sufficiently high temperature, and mud has lower moisture content, and the fed distance of mud is enough little.Otherwise moisture evaporation needs a large amount of heats in the mud, can cause boiler hearth temperature to reduce, the fuel fire difficulty, in addition flame-out.Sludge water content gets in the boiler exhaust gas, also can cause heat loss due to exhaust gas to increase, and boiler efficiency descends.

Adopt physics and chemical process with drying sludge, producing alternative fuel oil with the dewatered sludge pyrolysis is a kind of emerging recycling sludge and recovery energy technology.This technology mainly is meant carries out drying with containing the more sewage sludge of moisture with media such as warm air, hot flue gas or water vapour; Obtain the very low mud of moisture content; Organic combustible content in the dewatered sludge is improved; Thereby reduce the energy consumption of pyrolysis oil preparation process, improve the thermo-efficiency of pyrolysis oil preparation, reduce the oily cost of system.At present, the mud dried has high-temperature pressurizing thermal treatment and low temperature pressurized heat to handle two kinds of methods, all adopts indirect heating apparatus or direct heating device, can sludge water content be reduced to 30-45%.But these two kinds of methods all are heated to certain temperature with mud, make moisture evaporation, and energy consumption is higher.In the practice, fouling of heat exchangers and coking, parting liquid organic concentration height also can occur, be prone to distribute shortcomings such as stench, working cost height.

Organic combustiblecomponents content of sewage sludge is lower, when moisture content is very high, can not directly be used for burning or produces alternative fuel oil.Adopt conventional dry technology, not only the drying process energy consumption is high, and running cost is high, is prone to take place secondary pollution.Therefore direct pyrolysis oil preparation of sewage sludge or burning utilize technology is that all right ripe, and receive the restriction of running cost, energy consumption etc.It is high that the fluidised bed drying technology has dried heat efficient, the advantage that pollutent is few, but be mainly used in the solid materials drying at present, do not relate to for high-moisture mud.

Summary of the invention

In order to overcome the deficiency that existing sewage sludge drying means exists; The purpose of this invention is to provide a kind of sewage sludge and use drying installation; This device can reduce the drying process energy consumption; Save energy and the discharging that reduces greenhouse gases, it is dry that the present invention not only is fit to sewage sludge, also can be used for the drying of general mud.

The objective of the invention is to realize through following technical scheme:

A kind of sewage sludge is used drying installation; It is characterized in that: this device comprises fluidized-bed reactor, condensing heat exchanger, boiler air preheater, water pump, fan and booster fan; Be provided with heat-transfer pipe at the fluidized-bed reactor outside surface; Fluidized-bed reactor comprises feeding device, riser and air compartment, and materials device and riser are arranged on the fluidized-bed reactor middle part, and air compartment is positioned at the fluidized-bed reactor bottom; The live steam pipe connection that the entrance end of heat-transfer pipe and boiler come, exit end is connected with removing boiler tubing through water pump; One end of condensing heat exchanger is connected with the top of fluidized-bed reactor, and the other end is connected with the air compartment of fluidized-bed reactor with booster fan through boiler air preheater; Fan is connected with condensing heat exchanger.

Among the present invention, be provided with weary gas at the condensing heat exchanger place and remove boiler tubing and condensation-water drain.Between boiler air preheater and booster fan, be provided with the combustion air pipeline of boiler.

Among the present invention, the position of heat-transfer pipe and decoration form can be provided with as required.Heat-transfer pipe can tilt to be coated on the outside surface of fluidized-bed reactor middle part.

Be provided with blast cap and air distribution plate in the lower end of fluidized-bed reactor, air compartment communicates with the fluidized-bed reactor middle part through air distribution plate and blast cap.

When adopting the present invention that sewage sludge is carried out drying, be drying medium with warm air and water vapour, sewage sludge is carried out drying, detailed process is following:

Mud gets into fluidized-bed reactor through feeding device, and air gets into fluidized-bed reactor bottom air compartment after condensing heat exchanger and air preheater preheating, behind air distribution plate and blast cap, get into fluidized-bed reactor;

Mud granule in the fluidized-bed reactor moves upward with air draught, and absorbs the heat of air and heat-transfer pipe transmission;

After the mud granule temperature reached moisture and separates out temperature, the unboiled water steam was produced in the water analysis in the mud, and becomes wet air with air mixed; Wet air gets into condensing heat exchanger from fluidized-bed reactor top, with the heat transferred freezing air, wet air gets into boiler more then, participates in the boiler oil burning; Wet air is after the condensing heat exchanger heat release, and with the heat transferred freezing air and produce water of condensation, water of condensation is expelled to Sewage treatment systems;

The mud granule that is taken to fluidized-bed reactor top by air-flow falls back to the fluidized-bed reactor bottom around the longshore current fluidized bed reactor wall under the effect of gravity, proceed drying; Accomplishing the exsiccant mud granule discharges from the fluidized-bed reactor riser.

Said mud can be various forms of mud, can be the mixture of sewage sludge or road mud or two kinds of mud.The moisture mass content is 30%-90% in the mud.Mud dry weight in the fluidized-bed reactor is new wet more than 5 times of mud dry weight that add.

In use, regulate the flow of live steam and fluidization air, temperature and particle motion in the controlling flow fluidized bed reactor make mud granule drop down onto the fluidized-bed reactor bottom next time in action of gravity, prevent that mud granule from escaping and the entering condensing heat exchanger.The flow of adjustment mud and air pumps mud granule in fluidized-bed reactor, the fluidization campaign takes place.

The present invention is a drying medium with warm air and water vapour, to improve the utilization efficiency of heat energy of drying process.Sewage sludge gets into reactor drum through feeding device, and the fluidized wind entering air compartment with certain temperature from booster fan through air distribution plate and blast cap, gets into fluidized-bed reactor fluidized drying section then.Fluidized wind has certain flow velocity, makes mud granule in burner hearth, present the fluidization campaign, under suitable gas velocity, because the drag force effect makes mud granule move upward with air-flow.The water vapour that comes from boiler gets into heat-transfer pipe, and water vapor condensation is emitted heat, heating mud and fluidized wind, and produced simultaneously water of condensation is sent the boiler heat absorption back to through water pump, produces water vapour, supplies to recycle.Through the heat release of heat-transfer pipe, warm air and the effect of particulate intense mixing are the heat transferred mud granule.After the temperature of mud granule reached the moisture evaporation temperature, the moisture in the mud received heat evolution, produced water vapour, and mixed with fluidized wind, produced the higher wet air of temperature.On fluidized drying section top, because the effect of gravity, be fluidized mud granule that general mood stream takes top to the fluidisation dryer section of can not escaping out, fall back to the bottom around the mud granule longshore current dryer section wall.The fluidized drying section pumps mud granule, for particle drying provides time enough and heat.Accomplish the exsiccant mud granule and flow out, can be used as boiler oil or pyrolysis oil preparation raw material through riser.The dry wet air that generates gets into tubular heat exchanger from fluidized drying section top, after wet air and freezing air carried out heat exchange, part moisture was separated out in condensation, became the lower saturated moist air of temperature, can be directly as the combustion air of boiler.Freezing air is heated by wet air, after boiler air preheater further heats, is divided into two parts of fluidized wind and combustion air again, and fluidized wind gets into air compartment through booster fan, and combustion-supporting warm air then gets into boiler.

Mud involved in the present invention is meant the sewage sludge that contains organic combustiblecomponents that sewage work produces, and also can be the mud that other sewage treatment process produces.Contained combustiblecomponents is hydrocarbon organism in the mud, also can be other one or more combustiblecomponentss.

Compared with prior art, the present invention has stronger drying sludge ability, lower energy consumption for drying, long service life; Dried mud can be used for pyrolysis oil preparation and burning etc., the non-secondary pollution discharging.

The sewage sludge that the invention solves high-moisture is difficult to drying, energy consumption for drying is high and be prone to produce the difficult problem of secondary pollution, can be applicable to fields such as WWT, chemical industry, the energy, environmental protection.

Description of drawings

Fig. 1 is a structural representation of the present invention.

Among Fig. 1,1-fluidized-bed reactor, 2-riser, 3-feeding device, 4-heat-transfer pipe; The 5-blast cap, the 6-air distribution plate, the 7-air compartment, the 8-water pump, 9-removes boiler tubing; The 10-condensing heat exchanger, 11-is weary, and gas removes boiler tubing, 12-fan, 13-condensation-water drain; 14-boiler air preheater, 15-remove the combustion air pipeline of boiler, the live steam pipeline that the 16-boiler comes, 17-booster fan.

Embodiment

Describe the present invention in detail below in conjunction with Fig. 1.

A kind of sewage sludge of the present invention is used drying installation, is provided with heat-transfer pipe 4 at fluidized-bed reactor 1 outside surface, and heat-transfer pipe 4 tilts to be coated on the fluidized-bed reactor 1 middle part outside surface.Fluidized-bed reactor 1 comprisesfeeding device 3,riser 2,blast cap 5,air distribution plate 6 and air compartment 7, and air compartment 7 is positioned at fluidized-bed reactor 1 bottom, and air compartment 7 communicates with fluidized-bed reactor 1 middle part throughair distribution plate 6 and blast cap 5.Feeding device 3 is arranged on fluidized-bed reactor 1 middle part with riser 2.The entrance end of heat-transfer pipe 4 is connected with thelive steam pipeline 16 that boiler comes, and exit end is connected with removingboiler tubing 9 throughwater pump 8; One end of condensingheat exchanger 10 is connected with the top of fluidized-bed reactor 1, and the other end is connected with the air compartment 7 of fluidized-bed reactor 1 withbooster fan 17 throughboiler air preheater 14; Fan 12 is connected with condensing heat exchanger 10.Be provided with weary gas at condensingheat exchanger 10 places and removeboiler tubing 11 and condensation-water drain 13.Betweenboiler air preheater 14 andbooster fan 17, be provided with thecombustion air pipeline 15 of boiler.

During use, be drying medium with warm air and water vapour, sewage sludge is carried out drying, sewage sludge gets into fluidized-bed reactor 1 bottom through mud feeding device 3.Freezing air is after condensingheat exchanger 10 andair preheater 14 preheatings; Portion of air goes boiler to participate in burning through removing boiler auxiliarycombustion air line 15; Remaining air is through the air compartment 7 ofbooster fan 17 entering fluidized-bed reactors 1 bottom, and theblast cap 5 aboveair distribution plate 6 gets into fluidized-bed reactor 1.

Mud granule in the fluidized-bed reactor moves upward with air draught owing to the drag force effect.Thelive steam pipeline 16 that the water vapour that boiler produces comes through boiler gets into heat-transfer pipe 4 condensation heat releases, and liberated heat passes to mud granule and air, and mud granule absorbs the heat of air and heat-transfer pipe transmission.The water of condensation that produces is throughwater pump 8 and goboiler tubing 9 to return the boiler heat absorption, produces water vapour again.

After the mud granule temperature reached moisture and separates out temperature, the unboiled water steam was produced in the water analysis in the mud, and becomes wet air with air mixed; Wet air gets into condensingheat exchanger 10 from fluidized-bed reactor top, emit heat and separate out water of condensation, and wet air becomes the weary gas of low temperature then, removesboiler tubing 11 through weary gas, participates in boiler combustion.Water of condensation is expelled to Sewage treatment systems through condensation-water drain 13.

The mud granule that is taken to fluidized-bed reactor top by air-flow falls back to the fluidized-bed reactor bottom around the longshore current fluidized bed reactor wall under the effect of gravity, proceed drying; Regulate the flow of live steam and fluidization air, temperature and particle motion in the controlling flow fluidized bed reactor make mud granule drop down onto the fluidized-bed reactor bottom next time in action of gravity, prevent that mud granule from escaping and the entering condensing heat exchanger.The flow of adjustment mud and air pumps mud granule in fluidized-bed reactor, the fluidization campaign takes place.It is less to accomplish exsiccant mud granule quality, discharges from fluidized-bed reactor riser 2.

Among the present invention, related mud is meant the sewage sludge that contains organic combustiblecomponents that sewage work produces, and also can be the mud that other sewage treatment process produces.Contained combustiblecomponents is hydrocarbon organism in the mud, also can be other one or more combustiblecomponentss.The moisture mass content is 30%-90% in the mud.Mud dry weight in the fluidized-bed reactor is new wet more than 5 times of mud dry weight that add.

The present invention has stronger drying sludge ability, and the fluidized-bed reactor life-span is long; Dried mud can be used for pyrolysis oil preparation and burning etc., the non-secondary pollution discharging.

Claims (5)

1. a sewage sludge is used drying installation; It is characterized in that: this device comprises fluidized-bed reactor (1), condensing heat exchanger (10), boiler air preheater (14), water pump (8), fan (12) and booster fan (17); Be provided with heat-transfer pipe (4) at fluidized-bed reactor (1) outside surface; Fluidized-bed reactor (1) comprises feeding device (3), riser (2) and air compartment (7); Materials device (3) and riser (2) are arranged on fluidized-bed reactor (1) middle part, and air compartment (7) is positioned at fluidized-bed reactor (1) bottom; The entrance end of heat-transfer pipe (4) is connected with the live steam pipeline (16) that boiler comes, and exit end is connected with removing boiler tubing (9) through water pump (8); One end of condensing heat exchanger (10) is connected with the top of fluidized-bed reactor (1), and the other end is connected with the air compartment (7) of fluidized-bed reactor (1) with booster fan (17) through boiler air preheater (14); Fan (12) is connected with condensing heat exchanger (10).

2. sewage sludge according to claim 1 is used drying installation, it is characterized in that: locate to be provided with weary gas at condensing heat exchanger (10) and remove boiler tubing (11) and condensation-water drain (13).

3. sewage sludge according to claim 1 is used drying installation, it is characterized in that: the combustion air pipeline (15) that between boiler air preheater (14) and booster fan (17), is provided with boiler.

4. sewage sludge according to claim 1 is used drying installation, it is characterized in that: heat-transfer pipe (4) tilts to be coated on the outside surface of fluidized-bed reactor (1) middle part.

5. sewage sludge according to claim 1 is used drying installation; It is characterized in that: be provided with blast cap (5) and air distribution plate (6) in the lower end of fluidized-bed reactor (1), air compartment (7) communicates with fluidized-bed reactor (1) middle part through air distribution plate (6) and blast cap (5).

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