CN111995213A - Sludge treatment process - Google Patents
Sludge treatment process Download PDFInfo
- Publication number
- CN111995213A CN111995213A CN202010686453.XA CN202010686453A CN111995213A CN 111995213 A CN111995213 A CN 111995213A CN 202010686453 A CN202010686453 A CN 202010686453A CN 111995213 A CN111995213 A CN 111995213A
- Authority
- CN
- China
- Prior art keywords
- sludge
- flue gas
- pretreated
- treatment process
- gas
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 239000010802 sludge Substances 0.000 title claims abstract description 112
- 238000000034 method Methods 0.000 title claims abstract description 52
- 230000008569 process Effects 0.000 title claims abstract description 39
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 claims abstract description 66
- 239000003546 flue gas Substances 0.000 claims abstract description 66
- 238000001035 drying Methods 0.000 claims abstract description 43
- 238000002844 melting Methods 0.000 claims abstract description 39
- 230000008018 melting Effects 0.000 claims abstract description 39
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 35
- 238000002309 gasification Methods 0.000 claims abstract description 34
- CBENFWSGALASAD-UHFFFAOYSA-N Ozone Chemical compound [O-][O+]=O CBENFWSGALASAD-UHFFFAOYSA-N 0.000 claims abstract description 28
- 239000007789 gas Substances 0.000 claims abstract description 28
- 230000003750 conditioning effect Effects 0.000 claims abstract description 21
- 239000000428 dust Substances 0.000 claims abstract description 20
- 238000010521 absorption reaction Methods 0.000 claims abstract description 17
- 239000007921 spray Substances 0.000 claims abstract description 17
- 238000007254 oxidation reaction Methods 0.000 claims abstract description 16
- MWUXSHHQAYIFBG-UHFFFAOYSA-N nitrogen oxide Inorganic materials O=[N] MWUXSHHQAYIFBG-UHFFFAOYSA-N 0.000 claims abstract description 13
- 239000002893 slag Substances 0.000 claims abstract description 12
- 239000002918 waste heat Substances 0.000 claims abstract description 12
- 239000003513 alkali Substances 0.000 claims abstract description 10
- 239000012065 filter cake Substances 0.000 claims abstract description 9
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims abstract description 8
- 238000005086 pumping Methods 0.000 claims abstract description 7
- 238000003756 stirring Methods 0.000 claims abstract description 7
- 238000007599 discharging Methods 0.000 claims abstract description 5
- 238000006477 desulfuration reaction Methods 0.000 claims abstract description 4
- 230000023556 desulfurization Effects 0.000 claims abstract description 4
- 238000010791 quenching Methods 0.000 claims abstract description 4
- 230000000171 quenching effect Effects 0.000 claims abstract description 4
- XTQHKBHJIVJGKJ-UHFFFAOYSA-N sulfur monoxide Chemical class S=O XTQHKBHJIVJGKJ-UHFFFAOYSA-N 0.000 claims abstract description 4
- 229910052815 sulfur oxide Inorganic materials 0.000 claims abstract description 4
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 claims description 14
- 239000010881 fly ash Substances 0.000 claims description 14
- 230000018044 dehydration Effects 0.000 claims description 12
- 238000006297 dehydration reaction Methods 0.000 claims description 12
- 239000012528 membrane Substances 0.000 claims description 10
- 238000001125 extrusion Methods 0.000 claims description 9
- 239000003795 chemical substances by application Substances 0.000 claims description 8
- 238000002485 combustion reaction Methods 0.000 claims description 8
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 5
- 239000001301 oxygen Substances 0.000 claims description 5
- 229910052760 oxygen Inorganic materials 0.000 claims description 5
- 230000035484 reaction time Effects 0.000 claims description 5
- 238000001816 cooling Methods 0.000 claims description 3
- 238000005507 spraying Methods 0.000 claims description 3
- 150000002013 dioxins Chemical class 0.000 claims 1
- 230000000694 effects Effects 0.000 description 12
- 238000005265 energy consumption Methods 0.000 description 9
- HGUFODBRKLSHSI-UHFFFAOYSA-N 2,3,7,8-tetrachloro-dibenzo-p-dioxin Chemical compound O1C2=CC(Cl)=C(Cl)C=C2OC2=C1C=C(Cl)C(Cl)=C2 HGUFODBRKLSHSI-UHFFFAOYSA-N 0.000 description 4
- 235000008733 Citrus aurantifolia Nutrition 0.000 description 4
- 235000011941 Tilia x europaea Nutrition 0.000 description 4
- 239000004571 lime Substances 0.000 description 4
- 230000003647 oxidation Effects 0.000 description 4
- 238000000746 purification Methods 0.000 description 4
- 239000002002 slurry Substances 0.000 description 4
- 238000006243 chemical reaction Methods 0.000 description 3
- 239000003344 environmental pollutant Substances 0.000 description 3
- 229910001385 heavy metal Inorganic materials 0.000 description 3
- 239000007800 oxidant agent Substances 0.000 description 3
- 230000001590 oxidative effect Effects 0.000 description 3
- 231100000719 pollutant Toxicity 0.000 description 3
- 239000010865 sewage Substances 0.000 description 3
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 2
- 239000002253 acid Substances 0.000 description 2
- 239000002956 ash Substances 0.000 description 2
- 230000008859 change Effects 0.000 description 2
- 238000009264 composting Methods 0.000 description 2
- 238000000354 decomposition reaction Methods 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000003912 environmental pollution Methods 0.000 description 2
- 238000012423 maintenance Methods 0.000 description 2
- 238000010309 melting process Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 239000002994 raw material Substances 0.000 description 2
- 230000036632 reaction speed Effects 0.000 description 2
- 230000009467 reduction Effects 0.000 description 2
- 238000001179 sorption measurement Methods 0.000 description 2
- 238000003723 Smelting Methods 0.000 description 1
- 241000700605 Viruses Species 0.000 description 1
- 229910021529 ammonia Inorganic materials 0.000 description 1
- 244000052616 bacterial pathogen Species 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000007664 blowing Methods 0.000 description 1
- 239000011469 building brick Substances 0.000 description 1
- 239000004566 building material Substances 0.000 description 1
- 230000006835 compression Effects 0.000 description 1
- 238000007906 compression Methods 0.000 description 1
- 230000001143 conditioned effect Effects 0.000 description 1
- 238000011109 contamination Methods 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000004200 deflagration Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 238000004880 explosion Methods 0.000 description 1
- 239000004744 fabric Substances 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 239000012467 final product Substances 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 230000014759 maintenance of location Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 244000000010 microbial pathogen Species 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 238000006386 neutralization reaction Methods 0.000 description 1
- 229910000069 nitrogen hydride Inorganic materials 0.000 description 1
- 231100000252 nontoxic Toxicity 0.000 description 1
- 230000003000 nontoxic effect Effects 0.000 description 1
- 244000045947 parasite Species 0.000 description 1
- 238000009928 pasteurization Methods 0.000 description 1
- 238000001556 precipitation Methods 0.000 description 1
- 238000004064 recycling Methods 0.000 description 1
- 239000002689 soil Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- QXTCFDCJXWLNAP-UHFFFAOYSA-N sulfidonitrogen(.) Chemical compound S=[N] QXTCFDCJXWLNAP-UHFFFAOYSA-N 0.000 description 1
- 231100000331 toxic Toxicity 0.000 description 1
- 230000002588 toxic effect Effects 0.000 description 1
- 231100000419 toxicity Toxicity 0.000 description 1
- 230000001988 toxicity Effects 0.000 description 1
- 239000002912 waste gas Substances 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
- 239000002351 wastewater Substances 0.000 description 1
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F11/00—Treatment of sludge; Devices therefor
- C02F11/12—Treatment of sludge; Devices therefor by de-watering, drying or thickening
- C02F11/121—Treatment of sludge; Devices therefor by de-watering, drying or thickening by mechanical de-watering
- C02F11/122—Treatment of sludge; Devices therefor by de-watering, drying or thickening by mechanical de-watering using filter presses
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
- B01D53/14—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols by absorption
- B01D53/1431—Pretreatment by other processes
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
- B01D53/14—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols by absorption
- B01D53/1456—Removing acid components
- B01D53/1481—Removing sulfur dioxide or sulfur trioxide
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
- B01D53/14—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols by absorption
- B01D53/18—Absorbing units; Liquid distributors therefor
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
- B01D53/34—Chemical or biological purification of waste gases
- B01D53/46—Removing components of defined structure
- B01D53/54—Nitrogen compounds
- B01D53/56—Nitrogen oxides
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
- B01D53/34—Chemical or biological purification of waste gases
- B01D53/74—General processes for purification of waste gases; Apparatus or devices specially adapted therefor
- B01D53/76—Gas phase processes, e.g. by using aerosols
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F11/00—Treatment of sludge; Devices therefor
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F11/00—Treatment of sludge; Devices therefor
- C02F11/12—Treatment of sludge; Devices therefor by de-watering, drying or thickening
- C02F11/13—Treatment of sludge; Devices therefor by de-watering, drying or thickening by heating
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23G—CREMATION FURNACES; CONSUMING WASTE PRODUCTS BY COMBUSTION
- F23G7/00—Incinerators or other apparatus for consuming industrial waste, e.g. chemicals
- F23G7/001—Incinerators or other apparatus for consuming industrial waste, e.g. chemicals for sludges or waste products from water treatment installations
Abstract
The invention provides a sludge treatment process, which comprises the following steps: pumping sludge in the sludge concentration tank to a sludge conditioning tank, and stirring and conditioning to obtain pretreated sludge; pumping the pretreated sludge into a film filter press, and extruding and dehydrating to obtain a sludge cake; conveying the mud cakes to low-temperature drying equipment for drying treatment; the filter cake enters the gasification melting furnace to be gasified and melted to obtain molten slag and first pretreatment flue gas, the molten slag is discharged after water quenching, and the first pretreatment flue gas is purified by a cyclone dust collector and then is cooled by an air preheater and a waste heat boiler; the cooled first pretreated flue gas enters a gas mixer, and ozone is added into the gas mixer to carry out mixed oxidation reaction to obtain second pretreated flue gas; and (3) feeding the second pretreated flue gas into a spray absorption tower, and absorbing nitrogen and sulfur oxides in the second pretreated flue gas through alkali liquor, so as to realize desulfurization and denitrification. And purifying the second pretreated flue gas discharged from the spray absorption tower by a bag type dust collector and then discharging.
Description
Technical Field
The invention belongs to the technical field of sludge treatment, and particularly relates to a sludge treatment process.
Background
Sludge is the final product of sewage treatment, contains a large amount of toxic and harmful substances such as pathogenic microorganisms, parasites, heavy metals and the like, and is very important for avoiding serious secondary pollution to the environment. At present, the problem of sludge treatment has become a bottleneck restricting the sewage treatment industry, and is a difficult problem facing governments of all parts, so that the harmless treatment of sludge has become an environmental problem which needs to be solved urgently in China.
The existing foreign sludge treatment method generally comprises a process from a landfill method, a composting method, a drying method to an incineration method. However, the sludge treatment method which is common in China is to dehydrate the sludge until the water content is below 60% and then bury the sludge, and the method not only occupies a large amount of land, but also has the risk of pollution leakage. Composting can also cause soil or water contamination. The conventional sludge treatment method is a drying and incineration combined method, however, the conventional sludge incineration is very easy to generate century toxicity, namely dioxin, due to low incineration temperature, and the dioxin cannot be effectively removed by the conventional flue gas treatment facility. In addition, the fly ash that the sludge incineration produced belongs to the danger and gives up, and the waste residue has heavy metal to separate out the risk.
The existing sludge treatment processes are complex and various, but a full-flow process which can thoroughly solve the sludge pollution does not exist, and some problems exist. For example, deep dehydration of sludge requires drying by means of a heat source or addition of a solidifying agent such as lime, which results in high sludge treatment cost and high difficulty in wastewater and waste gas treatment. For tail gas treatment, a reduction method (SNCR) commonly used in the prior art is suitable for denitration modes at specific temperature (850 ℃ -1050 ℃) and in workplaces, the cost is high, the reduction method has large influence on hearth combustion, corrosion is caused to combustion chamber parts, and the risk of secondary pollution caused by ammonia escape exists. In addition, the existing sludge incineration treatment method can not treat the sludge with the water content of 96-99 wt%, and has high requirement on the heat value of raw materials, high energy consumption, high cost, complex process and great control difficulty.
Disclosure of Invention
In view of the above technical problems, the present invention is directed to inventing a sludge disposal process that can completely make sludge harmless, recyclable, and productive from a water content generation source, i.e., a sludge concentration tank.
To this end, according to the invention there is provided a sludge treatment process comprising the steps of:
pumping sludge in a sludge concentration tank to a sludge conditioning tank, adding an inorganic conditioning agent into the sludge conditioning tank, and stirring and conditioning to obtain pretreated sludge;
pumping the pretreated sludge into a film filter press for extrusion dehydration to obtain a sludge cake;
conveying the mud cakes to low-temperature drying equipment for drying treatment;
the dried filter cake enters a gasification melting furnace, and is gasified and melted to obtain molten slag and first pretreatment flue gas, the molten slag is discharged after water quenching, and the first pretreatment flue gas is purified by a cyclone dust collector and then sequentially enters an air preheater and a waste heat boiler for cooling;
the cooled first pretreated flue gas enters a gas mixer, and ozone is added into the gas mixer to carry out mixed oxidation reaction, so that second pretreated flue gas is obtained;
and feeding the second pretreated flue gas into a spray absorption tower, and spraying alkali liquor through the spray absorption tower to absorb nitrogen and sulfur oxides in the second pretreated flue gas so as to complete desulfurization and denitrification of the second pretreated flue gas.
And purifying the second pretreated flue gas discharged from the spray absorption tower by a bag type dust collector and then discharging.
In one embodiment, the inorganic conditioner is polyaluminum chloride or polyferric chloride, the addition amount of the polyaluminum chloride or the polyferric chloride is 5-20 wt% of the oven-dried sludge, and the stirring conditioning reaction time is 15-30 min.
In one embodiment, the membrane filter press performs press dehydration under a press pressure in the range of 1.4-2MPa for a press time of 30-60 min.
In one embodiment, the mud cake obtained after extrusion dewatering has a thickness of 0.5-1.5cm and a water content of 55-60 wt%.
In one embodiment, the drying temperature of the mud cake in the low-temperature drying equipment is 50-80 ℃, the oxygen content in the low-temperature drying equipment is not more than 12%, and the dust concentration is less than 60g/m3And the water content of the dried mud cake is not more than 30 wt%.
In one embodiment, the drying heat source of the low-temperature drying device adopts hot water heated by waste heat generated by the gasification melting furnace, and the temperature of the hot water is 85-90 ℃.
In one embodiment, the filter cake is subjected to drying, gasification and combustion treatment in the gasification melting furnace in sequence, so that organic matters in the filter cake are completely gasified and oxidized and combusted to obtain the molten slag, and the temperature for performing combustion treatment on the filter cake is 1200-1300 ℃.
In one embodiment, the first pre-treated flue gas enters a fly ash melting chamber before entering the cyclone dust collector to completely decompose dioxin, and air preheated by the air preheater is introduced into the fly ash melting chamber to completely combust the first pre-treated flue gas.
In one embodiment, the amount of ozone added to the gas mixer is 1-3g/Nm3First pre-treating the flue gas.
In one embodiment, the liquid-gas ratio of the alkali liquor sprayed by the spray absorption tower to the second pretreatment flue gas is 2-10L/m3。
Compared with the prior art, the method has the advantages that:
the sludge treatment process can directly treat the sludge in the sludge concentration tank, and is a full-flow process from sludge production to zero-pollution recycling. The pretreated sludge is formed by adopting a film filter press and extruding through a diaphragm, so that the use of a solidifying agent such as lime and the like is avoided, the dehydration mode with low energy consumption, namely mechanical dehydration, is fully utilized, the water content of a sludge cake is reduced, the energy consumption and the scale of subsequent drying are saved, and the energy consumption and the investment of the whole process are reduced. And the drying heat source of the low-temperature drying equipment utilizes hot water heated by waste heat generated by the gasification melting furnace, so that the use of an external heat source is avoided, the energy consumption is obviously reduced, the sludge treatment process is simplified, and the cost is saved. The sludge does not produce any pollutant in the gasification melting process, the sludge treatment process adopts ozone as an oxidant, can fully oxidize low-valent nitrogen oxides in the sludge melting tail gas, absorbs acid gas through alkali liquor and performs purification treatment for multiple times, the whole treatment process has no secondary pollution risk, and the environmental pollution is effectively avoided. In addition, the equipment used by the sludge treatment process occupies a small area, is low in operation control difficulty and operation and maintenance cost, and effectively saves the cost.
Drawings
The invention will now be described with reference to the accompanying drawings.
FIG. 1 is a schematic flow diagram of a sludge disposal process according to the present invention.
Detailed Description
The invention is described below with reference to the accompanying drawings.
FIG. 1 is a schematic flow diagram of a sludge disposal process according to the present invention. As shown in fig. 1, firstly, the sludge in the sludge concentration tank is pumped to the sludge conditioning tank to stir and condition the sludge. According to the invention, the sludge treatment process can directly treat the sludge in the sludge concentration tank. The sludge in the sludge concentration tank can be lifted by a submersible sewage pump or a self-priming centrifugal pump so as to be pumped to a sludge conditioning tank.
And (3) after the sludge is pumped to the sludge conditioning tank, adding an inorganic conditioning agent into the sludge conditioning tank, wherein the inorganic conditioning agent can be polyaluminium chloride or polyferric chloride. The addition amount of the polyaluminium chloride or the polyferric chloride is 5-20 wt% of the absolutely dry sludge. The polyaluminum chloride or the polyferric chloride can change the dehydration performance of the sludge through the actions of a compression double electric layer, adsorption electric neutralization, adsorption bridging and the like, and the adoption of the electrodeless conditioner can effectively avoid the blockage of the conventional PAM organic conditioner on the filter cloth of the filter press, thereby ensuring the treatment efficiency of the filter press. After the inorganic conditioner is added, the sludge in the sludge conditioning tank is stirred and conditioned by the sludge conditioning tank. Stirring and conditioning the reaction time for 15-30 min. Thereby, pretreated sludge was obtained.
Then, the pretreated sludge is pumped into a membrane filter press for press dewatering. In one embodiment, the pretreated sludge may be pumped to a membrane filter press using a centrifugal slurry pump. Thereby, one press dehydration is completed. The centrifugal slurry pump has a head in the range of 60-70m, preferably 70 m. The feeding curve of the centrifugal slurry pump is fitted with the filtering curve, the cavity of the membrane filter press is empty in the early stage, the centrifugal slurry pump is low in lift, and the flow is large. The sludge feeding time of the pretreated sludge is 5-15 min. And after the sludge feeding is finished, performing membrane extrusion on the pretreated sludge through a membrane filter press. Specifically, a diaphragm extrusion pump is adopted to pump the extrusion water into the filter press. The lift of the diaphragm extrusion pump is in the range of 160-200 m. The squeezing pressure of the membrane filter press for squeezing and dewatering is in the range of 1.4-2Mpa, and the squeezing time is in the range of 30-50 min. The pretreated sludge forms a mud cake after extrusion dehydration, the thickness of the mud cake is in the range of 0.5-1.5cm, the thickness of the mud cake can effectively reduce the mass transfer resistance of water in the mud cake, the dehydration efficiency is improved, and the water content of the sludge is reduced. The water content of the mud cake is 55-60 wt%, which is far lower than that of the mud cake with the water content of 70-80% after extrusion forming of a conventional filter press. The pretreated sludge is formed by adopting a membrane filter press and extruding through a membrane, so that the use of a curing agent such as lime and the like is avoided, the energy consumption can be reduced, and the cost is saved.
And then conveying the mud cake to a low-temperature drying device for drying treatment. In one embodiment, the mud cake is conveyed to a low temperature drying apparatus using a belt conveyor. The belt conveyor can improve mud cake conveying efficiency. The drying temperature in the low-temperature drying equipment is within the range of 50-60 ℃, and the low-temperature drying equipment is arranged in the low-temperature drying equipmentHas an oxygen content of not more than 12% and a dust concentration of less than 60g/m3. The water content of the mud cake dried by the low-temperature drying equipment is not more than 30 wt%. In the drying treatment process, because the low-temperature drying equipment has low oxygen content and low dust concentration, the risk of deflagration explosion can be effectively avoided, and the operation safety is ensured. Low temperature drying H2S、NH3Less precipitation, full-closed operation and no odor emission. In addition, the time of more than 70 ℃ is in the range of 90-120min, which can meet the pasteurization effect, thereby effectively avoiding secondary pollution of virus and germs to the environment. In one embodiment, the drying heat source of the low-temperature drying device can be hot water heated by waste heat generated by a gasification melting furnace (see below), and the temperature of the hot water is 85-90 ℃. Thus, the use of an additional heat source is avoided, the energy consumption is reduced, the cost is saved, and the environment is protected.
And then, sending the dried mud cake into a gasification melting furnace. In one embodiment, the mud cake is fed into the gasification and melting furnace through a screw conveyor and a star-shaped air seal, and is gasified and melted in the gasification and melting furnace. The height of the material layer formed by the mud cake fed into the gasification melting furnace is 2-3 m. The mud cake is subjected to drying, gasification, combustion and other treatment in the gasification melting furnace once, and the retention time in the gasification melting furnace is 1-2 h. In the combustion treatment stage, the temperature in the gasification melting furnace is set to be in the range of 1200-1300 ℃, and the pressure in the gasification melting furnace is set to be in the range of 20-30 Kpa. The method comprises the steps of feeding sludge into a gasification melting furnace for gasification melting treatment to produce inorganic molten slag and first pretreatment flue gas. The molten slag is melted in a gasification melting furnace at 1200-1300 ℃ high temperature environment, and forms a glass-like body to wrap pollutants such as heavy metals in the solidified sludge after cooling. The molten slag is discharged after water quenching, and can be used as a building material raw material. For example, the molten slag can be made into building bricks.
The first pretreatment flue gas generated by the gasification melting furnace is in a high-temperature environment of 1200-1300 ℃, the first pretreatment flue gas is introduced into the fly ash melting chamber and stays for 2s to completely decompose dioxin. Meanwhile, the fly ash carried by the first pretreatment flue gas is melted in the fly ash melting chamber. And, air preheated by an air preheater (see below) is introduced into the fly ash melting chamber to fully combust the combustible gas in the first pretreated flue gas.
And the first pre-treated flue gas enters a cyclone dust collector for dust removal and purification after passing through the fly ash melting chamber. The fly ash carried by the first pretreatment flue gas enters the cyclone dust collector and then falls into the ash bucket at the bottom of the cyclone dust collector, and the fly ash in the ash bucket of the cyclone dust collector can return to the gasification smelting furnace for further gasification melting treatment. And the first pre-treated flue gas purified by the cyclone dust collector enters an air preheater.
In this embodiment, the air preheater blows air through a booster blower. The blowing pressure of the air is 20-30 Kpa. The first pretreatment flue gas after being purified by the cyclone dust collector is high-temperature flue gas at 1200-1300 ℃, and the temperature of the air blown into the air preheater is raised to 500-600 ℃ under the heat exchange effect. The preheated air in the air preheater is kept at the temperature of 500-600 ℃, and is introduced into the gasification melting furnace, and a small amount of preheated air is introduced into the fly ash melting chamber to ensure that the combustible gas in the first pretreatment flue gas is fully combusted. Meanwhile, the high-temperature first pretreatment flue gas within the range of 1200-1300 ℃ is cooled to 800-900 ℃ through the heat exchange effect.
And then, introducing the first pretreated flue gas passing through the air preheater into a waste heat boiler, so that the temperature of the first pretreated flue gas is further reduced to 150-200 ℃. Circulating water is pumped into the waste heat boiler through a circulating pump, the circulating water is within the range of 50-60 ℃, the circulating water is heated to 85-90 ℃ through the heat exchange effect in the waste heat boiler, and the circulating water is circularly supplied to low-temperature drying equipment. Therefore, the circulating water is heated by utilizing waste heat generated by the gasification melting furnace, so that the temperature of the circulating water is 85-90 ℃, and the circulating water is further used as a drying heat source of the low-temperature drying equipment. Therefore, the heat of the gasification melting furnace is effectively utilized, the energy consumption in the sludge treatment process is reduced, the sludge treatment process can be simplified, and the cost is saved.
The first pre-treated flue gas is cooled by an air preheater and then enters a gas mixer. Simultaneously, adding ozone as an oxidant into the gas mixer so as to enable the first pretreated flue gas and the ozone to be mixed with oxygen in the gas mixerAnd carrying out chemical reaction to obtain second pretreated flue gas. Wherein, the ozone is prepared by an ozone generator and can be used at any time, thereby being nontoxic and harmless. The adding amount of ozone added into the gas mixer is 1-3g/Nm3The first pretreatment flue gas is beneficial to ensuring that the first pretreatment flue gas can be fully mixed and oxidized.
In one embodiment, the gas mixer may employ a venturi mixer. Ozone is put in through the gas mixer and can realize throwing to throw and go on with mixing in step to form the turbulent flow under the effect of putting into mouthful cross-section change of venturi mixer, thereby showing the mixed effect that improves ozone, improved mixed oxidation reaction's speed greatly, strengthened the oxidation efficiency of ozone. From this, realized through the gas blender that ozone mixes oxidation reaction with first preliminary treatment flue gas when throwing into, and realized through the venturi mixer that ozone is thrown and is thrown on blender and pipeline, raise the efficiency, save area.
Ozone is easily decomposed at high temperature, which affects the utilization efficiency of ozone, but the oxidation reaction speed of ozone is high at high temperature, and the oxidation effect is good. According to the invention, aiming at the characteristic of ozone, the ozone is added in a graded adding manner, so that multi-stage mixed oxidation reaction is carried out, the reaction time of each stage can be shortened, the ozone decomposition rate is reduced, and the oxidation effect of the ozone is ensured. Specifically, a plurality of gas mixers are provided. The first pretreated flue gas sequentially passes through the plurality of gas mixers to carry out multistage mixed oxidation reaction, so that second pretreated flue gas is obtained. The downstream end at each gas mixer corresponds and is provided with the whirl board, and the whirl board can further strengthen the mixed effect of first preliminary treatment flue gas and ozone to further strengthen mixed oxidation reaction effect, improve mixed oxidation reaction efficiency, accelerate the reaction and go on. Therefore, the ozone is put in a multi-stage mode and is subjected to graded mixed oxidation reaction, so that the reaction time of each stage is shortened, the ozone oxidation effect is ensured while the ozone decomposition rate is reduced, and the control difficulty of the whole process is reduced. In addition, low-valence nitrogen oxides in the first pretreated flue gas can be fully oxidized through a multi-stage mixed oxidation reaction, and the environment protection is facilitated.
And then, feeding the second pretreated flue gas into a spray absorption tower, and circularly pumping alkali liquor into the spray absorption tower to absorb nitrogen and sulfur oxides in the second pretreated flue gas, thereby completing the desulfurization and denitrification of the second pretreated flue gas. And injecting alkali liquor into the spray absorption tower in a spraying mode to spray the second pretreated flue gas entering the spray absorption tower. And the liquid-gas ratio of the alkali liquor sprayed by the spray absorption tower to the second pretreated flue gas is 2-10L/m3. This is very advantageous for improving the absorption of the lye on the nitrogen sulfide in the second pretreated flue gas.
And finally, introducing the second pretreated flue gas discharged from the spray absorption tower into a bag type dust collector for further purification treatment until the second pretreated flue gas reaches the standard and then discharging. And leading out the second pretreated flue gas which reaches the standard through a draught fan and discharging. And a small amount of fly ash carried in the second pretreatment flue gas is returned to the gasification melting furnace through the bag type dust collector to further carry out gasification melting reaction.
The sludge treatment process can treat the sludge with the water content of 96-99 wt%, has strong applicability, and can obviously enhance the sludge treatment effect. The pretreated sludge is formed by adopting a film filter press and extruding through a diaphragm, so that the use of a solidifying agent such as lime and the like is avoided, and a drying heat source of the low-temperature drying equipment utilizes hot water heated by waste heat generated by a gasification melting furnace, so that the use of an external heat source is avoided, the energy consumption is obviously reduced, the sludge treatment process is simplified, and the cost is saved. The sludge does not produce any pollutant in the gasification melting process, the sludge treatment process adopts ozone as an oxidant, can fully oxidize low-valent nitrogen oxides in the sludge melting tail gas, absorbs acid gas through alkali liquor and performs purification treatment for multiple times, the whole treatment process has no secondary pollution risk, and the environmental pollution is effectively avoided. In addition, the equipment used by the sludge treatment process occupies a small area, is low in operation control difficulty and operation and maintenance cost, and effectively saves the cost.
Finally, it should be noted that the above-mentioned embodiments are only preferred embodiments of the present invention, and do not limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that modifications may be made to the embodiments described in the foregoing examples, or that equivalents may be substituted for elements thereof. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (10)
1. A sludge treatment process is characterized by comprising the following steps:
pumping sludge in a sludge concentration tank to a sludge conditioning tank, adding an inorganic conditioning agent into the sludge conditioning tank, and stirring and conditioning to obtain pretreated sludge;
pumping the pretreated sludge into a film filter press for extrusion dehydration to obtain a sludge cake;
conveying the mud cakes to low-temperature drying equipment for drying treatment;
the dried filter cake enters a gasification melting furnace, and is gasified and melted to obtain molten slag and first pretreatment flue gas, the molten slag is discharged after water quenching, and the first pretreatment flue gas is purified by a cyclone dust collector and then sequentially enters an air preheater and a waste heat boiler for cooling;
the cooled first pretreated flue gas enters a gas mixer, and ozone is added into the gas mixer to carry out mixed oxidation reaction, so that second pretreated flue gas is obtained;
and feeding the second pretreated flue gas into a spray absorption tower, and spraying alkali liquor through the spray absorption tower to absorb nitrogen and sulfur oxides in the second pretreated flue gas so as to complete desulfurization and denitrification of the second pretreated flue gas.
And purifying the second pretreated flue gas discharged from the spray absorption tower by a bag type dust collector and then discharging.
2. The sludge treatment process according to claim 1, wherein the inorganic conditioner is polyaluminium chloride or polyferric chloride, the addition amount of the polyaluminium chloride or the polyferric chloride is 5-20 wt% of the absolutely dry sludge, and the stirring conditioning reaction time is 15-30 min.
3. The sludge disposal process of claim 1, wherein the membrane filter press performs press dehydration at a press pressure in the range of 1.4-2Mpa for a press time of 30-60 min.
4. The sludge treatment process according to claim 1 or 3, wherein the thickness of the mud cake obtained after the squeezing dehydration is 0.5-1.5cm, and the water content of the mud cake is 55-60 wt%.
5. The sludge treatment process of claim 1, wherein the drying temperature of the sludge cake in the low-temperature drying equipment is 50-80 ℃, the oxygen content in the low-temperature drying equipment is not more than 12%, and the dust concentration is less than 60g/m3And the water content of the dried mud cake is not more than 30 wt%.
6. The sludge treatment process according to claim 1 or 5, wherein the drying heat source of the low-temperature drying device adopts hot water heated by waste heat generated by the gasification melting furnace, and the temperature of the hot water is 85-90 ℃.
7. The sludge treatment process as claimed in claim 1, wherein the filter cake is subjected to drying, gasification and combustion treatment in the gasification melting furnace in sequence to completely gasify organic matters in the filter cake and oxidize and combust the organic matters to obtain the molten slag, and the temperature for performing the combustion treatment on the filter cake is 1200-1300 ℃.
8. The sludge treatment process of claim 1 wherein the first pre-treated flue gas enters a fly ash melting chamber before entering the cyclone to completely decompose dioxins, and air preheated by the air preheater is introduced into the fly ash melting chamber to completely combust the first pre-treated flue gas.
9. The sludge treatment process according to claim 1, wherein the amount of ozone added to the gas mixer is 1 to 3g/Nm3First pre-treating the flue gas.
10. The sludge treatment process of claim 1, wherein the liquid-gas ratio of the alkali liquor sprayed by the spray absorption tower to the second pretreatment flue gas is 2-10L/m3。
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010686453.XA CN111995213A (en) | 2020-07-16 | 2020-07-16 | Sludge treatment process |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010686453.XA CN111995213A (en) | 2020-07-16 | 2020-07-16 | Sludge treatment process |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN111995213A true CN111995213A (en) | 2020-11-27 |
Family
ID=73467422
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010686453.XA Pending CN111995213A (en) | 2020-07-16 | 2020-07-16 | Sludge treatment process |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111995213A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113371959A (en) * | 2021-06-01 | 2021-09-10 | 江苏国翔环保科技有限公司 | Sludge treatment system |
Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5234468A (en) * | 1991-06-28 | 1993-08-10 | Texaco Inc. | Process for utilizing a pumpable fuel from highly dewatered sewage sludge |
| WO2002021047A1 (en) * | 2000-09-05 | 2002-03-14 | Kawasaki Jukogyo Kabushiki Kaisha | Waste-gasified fusion furnace and method of operating the fusion furnace |
| JP2004249280A (en) * | 2003-01-31 | 2004-09-09 | Nippon Steel Corp | Gasification and melting method of sludge |
| JP2008132409A (en) * | 2006-11-27 | 2008-06-12 | Nippon Steel Corp | Gasification melting method and apparatus of sludge |
| CN103752151A (en) * | 2013-12-31 | 2014-04-30 | 浙江天蓝环保技术股份有限公司 | Technology for flue gas denitration by magnesium sulfite |
| CN103801176A (en) * | 2014-01-27 | 2014-05-21 | 浙江大学 | Flue gas denitration technology and flue gas denitration device implemented by combining ozonation and spraying cooling |
| CN105366896A (en) * | 2015-12-03 | 2016-03-02 | 上海澈底环保科技有限公司 | Device and process for sludge gasification melting circular treatment |
| CN205127706U (en) * | 2015-09-28 | 2016-04-06 | 北京蓝昊亚环环保设备有限公司 | Use ozone SOx/NOx control's integrated equipment |
| CN206334520U (en) * | 2016-12-22 | 2017-07-18 | 世纪华扬环境工程有限公司 | Odor at low temperature denitrification apparatus for hot-water boiler |
| CN107617317A (en) * | 2017-09-19 | 2018-01-23 | 北京首科兴业工程技术有限公司 | A kind of ultra-clean cleaning system of flue gas |
| CN111362551A (en) * | 2020-03-31 | 2020-07-03 | 中国华能集团清洁能源技术研究院有限公司 | Two-stage sludge drying and incinerating system of coal-fired power plant and operation method |
-
2020
- 2020-07-16 CN CN202010686453.XA patent/CN111995213A/en active Pending
Patent Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5234468A (en) * | 1991-06-28 | 1993-08-10 | Texaco Inc. | Process for utilizing a pumpable fuel from highly dewatered sewage sludge |
| WO2002021047A1 (en) * | 2000-09-05 | 2002-03-14 | Kawasaki Jukogyo Kabushiki Kaisha | Waste-gasified fusion furnace and method of operating the fusion furnace |
| JP2004249280A (en) * | 2003-01-31 | 2004-09-09 | Nippon Steel Corp | Gasification and melting method of sludge |
| JP2008132409A (en) * | 2006-11-27 | 2008-06-12 | Nippon Steel Corp | Gasification melting method and apparatus of sludge |
| CN103752151A (en) * | 2013-12-31 | 2014-04-30 | 浙江天蓝环保技术股份有限公司 | Technology for flue gas denitration by magnesium sulfite |
| CN103801176A (en) * | 2014-01-27 | 2014-05-21 | 浙江大学 | Flue gas denitration technology and flue gas denitration device implemented by combining ozonation and spraying cooling |
| CN205127706U (en) * | 2015-09-28 | 2016-04-06 | 北京蓝昊亚环环保设备有限公司 | Use ozone SOx/NOx control's integrated equipment |
| CN105366896A (en) * | 2015-12-03 | 2016-03-02 | 上海澈底环保科技有限公司 | Device and process for sludge gasification melting circular treatment |
| CN206334520U (en) * | 2016-12-22 | 2017-07-18 | 世纪华扬环境工程有限公司 | Odor at low temperature denitrification apparatus for hot-water boiler |
| CN107617317A (en) * | 2017-09-19 | 2018-01-23 | 北京首科兴业工程技术有限公司 | A kind of ultra-clean cleaning system of flue gas |
| CN111362551A (en) * | 2020-03-31 | 2020-07-03 | 中国华能集团清洁能源技术研究院有限公司 | Two-stage sludge drying and incinerating system of coal-fired power plant and operation method |
Non-Patent Citations (6)
| Title |
|---|
| 姬爱民等著: "《城市污泥热解转化机理及经济性评价》", 31 August 2016, 冶金工业出版社 * |
| 岳涛 等: "《工业锅炉大气污染控制技术与应用》", 31 October 2016, 中国环境出版社 * |
| 战佳宇 等: "《固体废物协同处置与综合利用》", 31 December 2014, 中国建材工业出版社 * |
| 牛冬杰 等: "《城市固体废物管理》", 30 July 2012, 中国城市出版社 * |
| 王仲旭等, 中国科学技术大学出版社 * |
| 雍毅 等: "《市政污泥特性与再生利用引论》", 31 March 2016, 中国环境出版社 * |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113371959A (en) * | 2021-06-01 | 2021-09-10 | 江苏国翔环保科技有限公司 | Sludge treatment system |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US11345637B2 (en) | Ozonation-based method for producing cementitious material | |
| US11154814B2 (en) | System and method for washing and treating fermentation odor and combustion flue gas | |
| CN104211274A (en) | Sludge reduction and recycling treatment device and sludge treatment method | |
| CN108187490A (en) | Macromolecule Dry denitration agent and preparation method thereof and denitrating technique and denitration device | |
| CN105366896A (en) | Device and process for sludge gasification melting circular treatment | |
| CN110759626A (en) | Sludge conditioning dehydration coupling carbonization reduction treatment method and system | |
| CN107867790A (en) | A kind of sludge confession heat dehydration drying means and system | |
| CN111499348A (en) | Production process of sintered brick | |
| WO2019062350A1 (en) | Harmless treatment method and system for domestic sludge | |
| CN211600730U (en) | Industrial sludge circulating fluidized bed incinerator | |
| CN112111302B (en) | Low-order material gasification combustion and flue gas pollutant control integrated process and device and application | |
| CN109574451A (en) | A kind of method of sludge drying comprehensive utilization | |
| CN111995213A (en) | Sludge treatment process | |
| WO2012100618A1 (en) | A method of disposing waste gas using double-effect-reactor combined with cement production and a system thereof | |
| CN204097297U (en) | Sludge reduction processing equipment for recycling | |
| CN106268230A (en) | A kind of waste heat of coke-oven flue gas reclaim and purify system and technique | |
| CN115849650A (en) | Municipal sludge treatment method | |
| CN116422311A (en) | Thermal regeneration device and regeneration method for activated carbon | |
| CN110762542A (en) | System and method for sludge and hazardous waste co-disposal | |
| CN206872653U (en) | A kind of sludge confesses heat dehydration drying system | |
| CN201713509U (en) | Automatic production line for manufacturing environment-friendly solid fuel by urban garbage without needing manual classification | |
| CN104353340B (en) | Gas cleaning after a kind of sludge incineration and reuse method and equipment thereof | |
| CN202808709U (en) | Sludge drying, pyrolysis gasifying and incinerating integrated treatment system | |
| CN207622028U (en) | Industrial pollutants compatibility burning processing system | |
| Zhang et al. | Status quo and resource utilization technology of sludge treatment and disposal |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20201127 |
|
| RJ01 | Rejection of invention patent application after publication |