Content of the invention
The present invention is directed to existing thermal desorption technology pollution environment and ineffective technical problem, proposes a kind of energyEnough realize zero waste gas emission, and can improve the organic efficiency of hydrargyrum and dust the thermal desorption system of process mercury contaminated soil andMethod.
In order to achieve the above object, the technical solution used in the present invention is：
A kind of thermal desorption system processing mercury contaminated soil, including the feed unit that can convey mercury contaminated soil, enters material listUnit is connected with can heat the thermal desorption unit that mercury contaminated soil makes hydrargyrum evaporate, and thermal desorption unit is provided with and can input mercury contaminated soilSoil entrance, and the gas outlet of mercurous mixed gas can be discharged, soil entrance is connected with the port of export of feed unit, gasBody exports the mixed gas processing mechanism of the hydrargyrum being connected with separable mercurous mixed gas and dust granule, and thermal desorption unit is alsoIt is provided with gas access, gas access is connected with the outlet side of mixed gas processing mechanism.
Preferably, mixed gas processing mechanism includes removing of gas phase in separable mercurous mixed gas and solid matterDirt unit, and mercurous mixed gas can be cooled down so that the condensing unit of mercury solution, the inlet end of dust removing units and thermal desorption listThe gas outlet of unit connects, and the outlet side of dust removing units is connected with condensing unit, the outlet side of condensing unit and thermal desorption unitGas access connect.
Preferably, be connected between the outlet side of mixed gas processing mechanism and thermal desorption unit gas access to conveyWaste gas to thermal desorption unit tail gas treating unit.
Preferably, tail gas treating unit includes removing the demister of fog in waste gas, the inlet end of demister with mixedThe outlet side closing gas treatment means connects, and the outlet side of demister is connected with the gas access of thermal desorption unit.
Preferably, tail gas treating unit includes the waste gas reheater that can heat waste gas, the inlet end of waste gas reheater withThe outlet side of demister connects, and the outlet side of waste gas reheater is connected with the gas access of thermal desorption unit.
Preferably, waste gas reheater is provided with the fire end that can heat waste gas in waste gas reheater, thermal desorption unit setsIt is equipped with the waste heat outlet of exportable thermal desorption unit waste heat, the waste heat outlet of thermal desorption unit is with the fire end of waste gas reheater evenConnect.
Preferably, condensing unit includes to the spray part of mercurous mixed gas spraying cooling, spraying the inlet end of partIt is connected with the outlet side of dust removing units, the outlet side of spray part is connected with the gas access of thermal desorption unit, spray part is provided withThe water inlet of cooling water can be inputted, and the exportable outlet containing mercury solution, the water inlet of spray part be connected with can provide coldBut the water cooling unit of water, the outlet of spray part is connected with the hydrargyrum water separative element of separable hydrargyrum.
Preferably, the water side of hydrargyrum water separative element is connected with water cooling unit.
A kind of process mercury contaminated soil thermal desorption method it is characterised in that：Comprise the following steps,
S0：Pending mercury contaminated soil is inputted by feed unit and is processed to thermal desorption unit, heat is de-The heating of coupon unit, so that the mercury vapour in mercury contaminated soil；
S1：The soil isolated through thermal desorption unit is discharged after cooling, the mercurous mixing isolated through thermal desorption unitGas inputs to mixed gas processing mechanism, to carry out to the hydrargyrum in mercurous mixed gas and dust separating, to discharge waste gas；
S2：The waste gas discharged from mixed gas processing mechanism is inputted de- to heat by the gas access of thermal desorption unitIn coupon unit, to accelerate the circulation of the mercurous mixed gas of volatilization in thermal desorption unit.
A kind of process mercury contaminated soil thermal desorption method it is characterised in that：Comprise the following steps,
S0：Pending mercury contaminated soil is inputted by feed unit and is processed to thermal desorption unit, heat is de-The heating of coupon unit, so that the mercury vapour in mercury contaminated soil；
S3：The soil isolated through thermal desorption unit is discharged after cooling, the mercurous mixing isolated through thermal desorption unitGas inputs to dust removing units, is separated the dust granule in mercurous mixed gas by dust removing units, meanwhile, after processingMercurous mixed gas are discharged from dust removing units；
S4：The mercurous mixed gas discharged from dust removing units are inputted to spray part, to enter to mercurous mixed gasRow cooling is processed, and meanwhile, makes hydrargyrum cooling liquid, and will contain mercury solution from spray part discharge；
S5：Input discharge from spray part to hydrargyrum water separative element containing mercury solution, to enter to containing the hydrargyrum in mercury solutionRow separates, and the water that will obtain after processing is from the discharge of hydrargyrum water separative element；
S6：The water discharged from hydrargyrum water separative element is inputted to water cooling unit, so that cooling treatment is carried out to water, and willCooling water after cooling treatment is discharged from water cooling unit；
S7：The cooling water discharged from water cooling unit is inputted to spray part, with to the mercurous gaseous mixture in spray partBody carries out cooling treatment.
Compared with prior art, advantages of the present invention and good effect are：
1st, the thermal desorption system of present invention process mercury contaminated soil is passed through the gas access of thermal desorption unit and gaseous mixtureThe outlet side of body processing mechanism connects, and, utilizes so that the waste gas that mixed gas processing mechanism produces obtains cycling and reutilization, meanwhileWaste gas purges to the mercurous mixed gas of volatilization in thermal desorption unit, thus accelerating the flowing of mercurous mixed gas, entersAnd achieve the zero-emission of waste gas, and reduce the amount processing activated carbon needed for waste gas, meanwhile, improve whole thermal desorption dressPut the organic efficiency to hydrargyrum and dust.
2nd, the present invention processes the thermal desorption system of mercury contaminated soil by setting spray part, hydrargyrum water separative element and water coolingUnit, and hydrargyrum water separative element and water cooling unit are connected, so that the waste water through the output of hydrargyrum water separative element is circulatedRecycle, in spray part, mercurous mixed gas are cooled down using waste water meanwhile, it is achieved thereby that the zero-emission of waste water,Meanwhile, saved cost.
Specific embodiment
Below, by exemplary embodiment, the present invention is specifically described.It should be appreciated, however, that not entering oneIn the case of step narration, the element in an embodiment, structure and features can also be advantageously incorporated into other embodimentIn.
As shown in figure 1, a kind of thermal desorption system processing mercury contaminated soil, enter material list including can convey mercury contaminated soilUnit, feed unit is connected with and can heat the thermal desorption unit that mercury contaminated soil makes hydrargyrum evaporate, and thermal desorption unit is provided with and can inputThe soil entrance of mercury contaminated soil, and the gas outlet of mercurous mixed gas can be discharged, soil entrance is gone out with feed unitMouthful end connects, and gas outlet is connected with the mixed gas processing mechanism of hydrargyrum in separable mercurous mixed gas and dust granule,Thermal desorption unit is additionally provided with gas access, and gas access is connected with the outlet side of mixed gas processing mechanism.
The thermal desorption system that the present invention processes mercury contaminated soil is passed through the gas access of thermal desorption unit and mixed gasThe outlet side of processing mechanism connects, so that the waste gas that mixed gas processing mechanism produces obtains cycling and reutilization, meanwhile, using uselessGas purges to the mercurous mixed gas of volatilization in thermal desorption unit, thus accelerating the flowing of mercurous mixed gas, and thenAchieve the zero-emission of waste gas, meanwhile, improve the organic efficiency to hydrargyrum and dust for the whole thermal desorption device.
Further, thermal desorption unit can be connected with the soil collecting means that can receive soil after thermal desorption unit output is processed,Thermal desorption unit is provided with the soil outlet of exportable soil after processing, and soil outlet is connected with soil collecting means.
For the structure of above-mentioned mixed gas processing mechanism, specially：Mixed gas processing mechanism includes separable mercurousGas phase in mixed gas and the dust removing units of solid matter, and mercurous mixed gas can be cooled down so that the condensation list of mercury solutionUnit 2, the inlet end of dust removing units is connected with the gas outlet of thermal desorption unit, and the outlet side of dust removing units is with condensing unit 2 evenConnect, the outlet side of condensing unit 2 is connected with the gas access of thermal desorption unit.Present invention setting dust removing units and condensing unit 2Effect be, be capable of the mercurous mixed gas discharged from thermal desorption unit are carried out successively with the process of dedusting and the removal of mercury,And then improve the purification efficiency to mercurous mixed gas.
Preferably, dust removing units can be one kind of for cyclone dust extractor, sack cleaner or electric cleaner.
Further, be connected between the outlet side of mixed gas processing mechanism and thermal desorption unit gas access can convey uselessGas to thermal desorption unit tail gas treating unit 1.
For the structure of above-mentioned tail gas treating unit 1, specially：Tail gas treating unit 1 includes removing fog in waste gasDemister, the inlet end of demister is connected with the outlet side of mixed gas processing mechanism, the outlet side of demister and thermal desorptionThe gas access of unit connects.The effect that the present invention arranges demister is, can discharge waste gas to from mixed gas processing mechanismIn steam and the hydrargyrum that is adsorbed in steam carry out separating, to be additionally separated to hydrargyrum.
Further, tail gas treating unit 1 also includes the waste gas reheater that can heat waste gas, the inlet end of waste gas reheater withThe outlet side of demister connects, and the outlet side of waste gas reheater is connected with the gas access of thermal desorption unit.Present invention setting is uselessThe effect of gas reheater is, by inputting heat-treated waste gas to thermal desorption unit, to assist thermal desorption unitSupplying heat source in thermal desorption unit mercury contaminated soil heat, thus the energy decreasing thermal desorption unit supplying heat source is defeatedGo out, and then saved cost.
In addition, waste gas reheater is provided with the fire end that can heat waste gas in waste gas reheater, thermal desorption unit is provided withExportable thermal desorption unit waste heat (if thermal desorption unit is heated by the sky steam that burns, the carrier of waste heat is flue gas)Waste heat exports, and the waste heat outlet of thermal desorption unit is connected with the fire end of waste gas reheater.The acting on of the above-mentioned setting of the present inventionIn, the utilization to thermal desorption unit waste heat for the realization, to avoid the waste of waste heat, meanwhile, decrease thermal desorption unit supplying heat sourceEnergy exports, and then has saved cost.
Further, tail gas treating unit 1 also includes the activated carbon adsorption part of hydrargyrum in separable waste gas, and activated carbon adsorption part isOutlet side with condensing unit 2 as shown in Figure 1 is connected, now, the outlet side of activated carbon adsorption part and atmosphere；Additionally,Activated carbon adsorption part is also connected in the gas circuit that mist eliminator and waste gas reheater are located.
For the structure of above-mentioned condensing unit 2, specially：As shown in figure 1, condensing unit 2 include can be to mercurous gaseous mixtureThe spray part of body spraying cooling, the inlet end of spray part is connected with the outlet side of dust removing units, and the outlet side of spray part and heat take offThe gas access of coupon unit connects, and spray part is provided with the water inlet that can input cooling water, and exportable going out containing mercury solutionThe mouth of a river, the water inlet of spray part is connected with the water cooling unit that can provide cooling water, and the outlet of spray part is connected with separableThe hydrargyrum water separative element of hydrargyrum.
In addition, the water side of hydrargyrum water separative element is connected with water cooling unit.The heat that the present invention processes mercury contaminated soil takes offAttached system passes through setting spray part, hydrargyrum water separative element and water cooling unit, and by hydrargyrum water separative element and water cooling unitConnect so that through hydrargyrum water separative element output waste water obtain cycling and reutilization, meanwhile, using waste water spray part in mercurousMixed gas are cooled down, it is achieved thereby that the zero-emission of waste water, meanwhile, have saved cost.
Further, condensing unit 2 also includes the condensing part that the mixed gas of spray part output can be cooled down further, condensationThe inlet end of part is connected with the outlet side of spray part, and the outlet side of condensing part is connected with the gas access of thermal desorption unit, condensationPart is provided with the exportable condensing part outlet containing mercury solution, and condensing part outlet is connected with hydrargyrum water separative element, and condensing part is evenIt is connected to the refrigeration machine that condensing part cold-producing medium can be provided.The present invention passes through setting spray part and condensing part, to realize to mercurous mixingGas carries out two grades of coolings, to be sufficiently separated the hydrargyrum in mercurous mixed gas.
Preferably, hydrargyrum water separative element is that hydrocyclone, centrifuge or sedimentation tank are one kind of.
With further reference to such as Fig. 1, the invention still further relates to a kind of thermal desorption method processing mercury contaminated soil, walk including followingSuddenly：
S0：Pending mercury contaminated soil is inputted by feed unit and is processed to thermal desorption unit, heat is de-The heating of coupon unit, so that the mercury vapour in mercury contaminated soil.
For the processing procedure of thermal desorption unit in step S0, specially：Pretreated homogenizing is contained mercury contaminated soilIt is delivered in thermal desorption unit and is processed, mercury contaminated soil indirectly heat will be contained by fuel combustion mode, so that mercurous dirtThere is gasification volatilization in the hydrargyrum in dye soil and moisture, and realize and being completely separated of solid phase.
Preferably, thermal desorption unit will contain mercury contaminated soil and be heated to 350～600 DEG C, and heat time heating time be 30～60min.
S1：The soil isolated through thermal desorption unit is discharged after cooling, the mercurous mixing isolated through thermal desorption unitGas inputs to mixed gas processing mechanism, to carry out to the hydrargyrum in mercurous mixed gas and dust separating, to discharge waste gas.
The method processing mercurous mixed gas for mixed gas processing mechanism in step S1, specifically, include step S3：The soil isolated through thermal desorption unit is discharged after cooling, inputs to removing through the mercurous mixed gas that thermal desorption unit is isolatedDust granule in mercurous mixed gas is separated by dirt unit by dust removing units, meanwhile, by the mercurous mixed gas after processingDischarge from dust removing units.
Further, the mercurous mixed gas after processing are expelled to condensing unit 2, in said process, mercurous mixed for preventingClose gas cooling, dust removing units can be by the thick insulation material parcel of 40～150mm.
The method mercurous mixed gas being processed for above-mentioned condensing unit 2, specifically, include step S4:Will be from dedustingThe mercurous mixed gas discharged in unit input to spray part, to carry out cooling process to mercurous mixed gas, meanwhile, make hydrargyrumCooling liquid, and mercury solution will be contained from spray part discharge.
Preferably, acted on by the spray of spray unit, the temperature of mercurous mixed gas can be down to 40～70 DEG C.
Further, the method that condensing unit 2 is processed to mercurous mixed gas also includes step S5：By discharge from spray partInput to hydrargyrum water separative element containing mercury solution, to carry out separating to containing the hydrargyrum in mercury solution, and after processing the water that obtain fromHydrargyrum water separative element is discharged.
Further, the method that condensing unit 2 is processed to mercurous mixed gas also includes step S6：Will be from hydrargyrum water separative elementThe water discharged inputs to water cooling unit, to carry out cooling treatment to water, and by the cooling water after cooling treatment from water coolingUnit is discharged；
Further, the method that condensing unit 2 is processed to mercurous mixed gas also includes step S7：To arrange from water cooling unitThe cooling water going out inputs to spray part, to carry out cooling treatment to the mercurous mixed gas in spray part；
In addition, the method that condensing unit 2 is processed to mercurous mixed gas also includes：The mercurous mixing that will discharge from spray partGas is delivered in condensing part, and condensing part further cools down to mercurous mixed gas, and discharges useless to tail gas treating unitGas.
Preferably, the temperature of mercurous mixed gas can be further reduced to 0～10 DEG C by condensing part.
S2：The waste gas discharged from mixed gas processing mechanism is inputted de- to heat by the gas access of thermal desorption unitIn coupon unit, to accelerate the circulation of the mercurous mixed gas of volatilization in thermal desorption unit.
In addition, step S2 is further comprising the steps of：The drying through mist eliminator for the waste gas, and logical after the heating of waste gas reheaterThe gas access crossing thermal desorption unit inputs to thermal desorption unit, to accelerate the mercurous mixed gas of volatilization in thermal desorption unitCirculation, during, if desired for outside drain waste gas, then first to waste gas after activated carbon adsorption part removal of mercury process, then dischargeTo air.
After tested, the application present invention processes the thermal desorption system of mercury contaminated soil and method with the treating capacity of 8t/h, withAnd under 350～600 DEG C of thermal desorption unit internal operating temperature, process to containing mercury contaminated soil, obtain Mercury In SoilConcentration is less than 10mg/kg, and meanwhile, tail gas reaches after treatment《Discharge standard of air pollutants》(GB16297-1996).