CN117128523A - Domestic sludge self-sustaining incineration process and equipment - Google Patents
Domestic sludge self-sustaining incineration process and equipment Download PDFInfo
- Publication number
- CN117128523A CN117128523A CN202311395320.7A CN202311395320A CN117128523A CN 117128523 A CN117128523 A CN 117128523A CN 202311395320 A CN202311395320 A CN 202311395320A CN 117128523 A CN117128523 A CN 117128523A
- Authority
- CN
- China
- Prior art keywords
- sludge
- drying
- gas
- flue gas
- air
- 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.)
- Granted
Links
- 239000010802 sludge Substances 0.000 title claims abstract description 224
- 238000000034 method Methods 0.000 title claims abstract description 78
- 238000001035 drying Methods 0.000 claims abstract description 155
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 claims abstract description 149
- 239000003546 flue gas Substances 0.000 claims abstract description 147
- 239000007789 gas Substances 0.000 claims abstract description 103
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 103
- 238000002485 combustion reaction Methods 0.000 claims abstract description 38
- 238000000926 separation method Methods 0.000 claims abstract description 30
- 238000002156 mixing Methods 0.000 claims abstract description 25
- 238000010298 pulverizing process Methods 0.000 claims abstract description 7
- 239000010865 sewage Substances 0.000 claims description 58
- 239000002956 ash Substances 0.000 claims description 38
- 239000002893 slag Substances 0.000 claims description 36
- 238000005273 aeration Methods 0.000 claims description 26
- 238000005406 washing Methods 0.000 claims description 24
- 238000010438 heat treatment Methods 0.000 claims description 21
- 239000003344 environmental pollutant Substances 0.000 claims description 17
- 231100000719 pollutant Toxicity 0.000 claims description 17
- 239000000428 dust Substances 0.000 claims description 16
- 239000000203 mixture Substances 0.000 claims description 16
- 238000007599 discharging Methods 0.000 claims description 14
- 239000007787 solid Substances 0.000 claims description 13
- 239000000463 material Substances 0.000 claims description 11
- 238000011065 in-situ storage Methods 0.000 claims description 8
- 238000004064 recycling Methods 0.000 claims description 8
- 239000002918 waste heat Substances 0.000 claims description 7
- 238000004332 deodorization Methods 0.000 claims description 6
- 238000001816 cooling Methods 0.000 claims description 5
- 238000001125 extrusion Methods 0.000 claims description 4
- 239000000446 fuel Substances 0.000 abstract description 12
- 238000005276 aerator Methods 0.000 description 19
- 239000012528 membrane Substances 0.000 description 10
- MWUXSHHQAYIFBG-UHFFFAOYSA-N nitrogen oxide Inorganic materials O=[N] MWUXSHHQAYIFBG-UHFFFAOYSA-N 0.000 description 9
- 239000002245 particle Substances 0.000 description 7
- 239000007788 liquid Substances 0.000 description 6
- 239000000843 powder Substances 0.000 description 6
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 5
- 239000001301 oxygen Substances 0.000 description 5
- 229910052760 oxygen Inorganic materials 0.000 description 5
- 239000000779 smoke Substances 0.000 description 5
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 4
- RAHZWNYVWXNFOC-UHFFFAOYSA-N Sulphur dioxide Chemical compound O=S=O RAHZWNYVWXNFOC-UHFFFAOYSA-N 0.000 description 4
- 229910052799 carbon Inorganic materials 0.000 description 4
- 230000000694 effects Effects 0.000 description 4
- 238000012856 packing Methods 0.000 description 4
- 230000001105 regulatory effect Effects 0.000 description 4
- 238000010586 diagram Methods 0.000 description 3
- 239000010813 municipal solid waste Substances 0.000 description 3
- 238000000746 purification Methods 0.000 description 3
- 239000007921 spray Substances 0.000 description 3
- 229920003051 synthetic elastomer Polymers 0.000 description 3
- 239000005061 synthetic rubber Substances 0.000 description 3
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 2
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 2
- 239000004743 Polypropylene Substances 0.000 description 2
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- 238000005299 abrasion Methods 0.000 description 2
- 239000004566 building material Substances 0.000 description 2
- 230000001276 controlling effect Effects 0.000 description 2
- 229920001971 elastomer Polymers 0.000 description 2
- IXCSERBJSXMMFS-UHFFFAOYSA-N hydrogen chloride Substances Cl.Cl IXCSERBJSXMMFS-UHFFFAOYSA-N 0.000 description 2
- 229910000041 hydrogen chloride Inorganic materials 0.000 description 2
- -1 polypropylene Polymers 0.000 description 2
- 229920001155 polypropylene Polymers 0.000 description 2
- 239000005060 rubber Substances 0.000 description 2
- 239000000741 silica gel Substances 0.000 description 2
- 229910002027 silica gel Inorganic materials 0.000 description 2
- 230000002269 spontaneous effect Effects 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 239000000725 suspension Substances 0.000 description 2
- 238000012546 transfer Methods 0.000 description 2
- 238000009834 vaporization Methods 0.000 description 2
- 230000008016 vaporization Effects 0.000 description 2
- 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 1
- 239000004433 Thermoplastic polyurethane Substances 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000002457 bidirectional effect Effects 0.000 description 1
- 150000001720 carbohydrates Chemical class 0.000 description 1
- 229910002092 carbon dioxide Inorganic materials 0.000 description 1
- 239000001569 carbon dioxide Substances 0.000 description 1
- 230000015556 catabolic process Effects 0.000 description 1
- 239000004568 cement Substances 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 239000003245 coal Substances 0.000 description 1
- 239000000356 contaminant Substances 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000006731 degradation reaction Methods 0.000 description 1
- 230000018044 dehydration Effects 0.000 description 1
- 238000006297 dehydration reaction Methods 0.000 description 1
- 238000006477 desulfuration reaction Methods 0.000 description 1
- 230000023556 desulfurization Effects 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 238000005265 energy consumption Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 238000003912 environmental pollution Methods 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 238000004880 explosion Methods 0.000 description 1
- 239000010881 fly ash Substances 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 238000011835 investigation Methods 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 230000014759 maintenance of location Effects 0.000 description 1
- 230000000813 microbial effect Effects 0.000 description 1
- 239000003595 mist Substances 0.000 description 1
- 238000012544 monitoring process Methods 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 230000000704 physical effect Effects 0.000 description 1
- 230000008092 positive effect Effects 0.000 description 1
- 102000004169 proteins and genes Human genes 0.000 description 1
- 108090000623 proteins and genes Proteins 0.000 description 1
- 238000000197 pyrolysis Methods 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 239000011343 solid material Substances 0.000 description 1
- 239000004071 soot Substances 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
- XTQHKBHJIVJGKJ-UHFFFAOYSA-N sulfur monoxide Chemical class S=O XTQHKBHJIVJGKJ-UHFFFAOYSA-N 0.000 description 1
- 229910052815 sulfur oxide Inorganic materials 0.000 description 1
- 229920002803 thermoplastic polyurethane Polymers 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
Classifications
-
- 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
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23G—CREMATION FURNACES; CONSUMING WASTE PRODUCTS BY COMBUSTION
- F23G5/00—Incineration of waste; Incinerator constructions; Details, accessories or control therefor
- F23G5/02—Incineration of waste; Incinerator constructions; Details, accessories or control therefor with pretreatment
- F23G5/04—Incineration of waste; Incinerator constructions; Details, accessories or control therefor with pretreatment drying
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23G—CREMATION FURNACES; CONSUMING WASTE PRODUCTS BY COMBUSTION
- F23G5/00—Incineration of waste; Incinerator constructions; Details, accessories or control therefor
- F23G5/44—Details; Accessories
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23G—CREMATION FURNACES; CONSUMING WASTE PRODUCTS BY COMBUSTION
- F23G5/00—Incineration of waste; Incinerator constructions; Details, accessories or control therefor
- F23G5/44—Details; Accessories
- F23G5/46—Recuperation of heat
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23J—REMOVAL OR TREATMENT OF COMBUSTION PRODUCTS OR COMBUSTION RESIDUES; FLUES
- F23J15/00—Arrangements of devices for treating smoke or fumes
- F23J15/02—Arrangements of devices for treating smoke or fumes of purifiers, e.g. for removing noxious material
- F23J15/022—Arrangements of devices for treating smoke or fumes of purifiers, e.g. for removing noxious material for removing solid particulate material from the gasflow
- F23J15/025—Arrangements of devices for treating smoke or fumes of purifiers, e.g. for removing noxious material for removing solid particulate material from the gasflow using filters
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23J—REMOVAL OR TREATMENT OF COMBUSTION PRODUCTS OR COMBUSTION RESIDUES; FLUES
- F23J15/00—Arrangements of devices for treating smoke or fumes
- F23J15/06—Arrangements of devices for treating smoke or fumes of coolers
Abstract
The invention provides a self-sustaining incineration process of domestic sludge, which comprises the steps of primary drying, secondary drying, crushing and incineration; the domestic sludge is dried for the first time by using dry hot air to obtain sludge with the water content of 40-55%; then the hot flue gas from incineration is used for secondary drying to obtain sludge with the water content not higher than 20%; further pulverizing, mixing with the hot ash from incineration, then self-sustaining incinerating in an incinerator at 850-950 ℃, carrying out solid-gas separation on the high-temperature flue gas after combustion, returning the obtained hot flue gas to secondary drying, and mixing the obtained hot ash with the pulverized sludge. The invention also provides equipment for the treatment process. The treatment process can safely and stably complete self-sustaining combustion after drying pretreatment of the high-water-content domestic sludge, does not need to add auxiliary fuel in the incineration process, can fully utilize heat energy of a system, and can realize reduction treatment of the domestic sludge.
Description
Technical Field
The invention relates to a sludge treatment process, further relates to a combustion treatment process of sludge and equipment for the process.
Background
In recent years, rural town process is accelerated, after a sewage pipe network unifies nano pipes, the sludge is large in quantity and complex in composition, part of sludge is derived from solid suspended matters after domestic sewage treatment, common organic matters are saccharides, fat and protein, and the sludge treatment problem is very serious.
Sludge incineration is one of the most direct and effective ways of sludge reduction. In the traditional treatment process, most of the incineration treatment of sludge is to transport the sludge after mechanical dehydration to a special garbage incineration site or a power plant, and add a large amount of auxiliary fuel for blending combustion. The consumption of auxiliary fuel is huge, and the auxiliary fuel is neither economical nor environment-friendly. In addition, in order to reduce the consumption of auxiliary fuel during blending combustion, the treatment process can carry out high-energy-consumption drying pretreatment on the sludge before incineration, and the water content of the sludge is reduced through drying, so that the amount of auxiliary fuel required to be added during subsequent blending combustion is reduced. However, there are still many problems to be solved in the drying pretreatment of sludge. The drying pretreatment of the sludge can be divided into full drying and half drying. The sludge has high heat value after full drying, is easy to burn, but also easily generates dust, and has the danger of spontaneous combustion and spontaneous explosion. The semi-dried sludge still contains a large amount of water when entering the furnace, and impacts the furnace temperature, so that the fluctuation of the furnace temperature and the unstable furnace condition are caused. This results in that most of sludge in the prior art can be used as a co-fired material only after semi-drying, and can be co-disposed with garbage incineration power plants, cement kilns, coal-fired power plants and the like, or the co-fired auxiliary fuel is still required during incineration. For example, chinese patent documents CN108892349A, CN105948459A, CN110104935A and CN107420915A both disclose a treatment process of drying and pre-treating sludge and then incinerating the sludge. However, in these methods, a large amount of auxiliary fuel is still required to be added to the sludge incineration after the drying treatment. In a word, most of the existing semi-dried sludge can only be subjected to blending combustion treatment, so that the blending combustion amount in the treatment is limited, and the semi-dried sludge blending combustion can bring a series of defects of reducing the temperature in a furnace and the softening point of ash, increasing the fly ash generation amount, increasing the dedusting and flue gas purification loads, reducing the boiler efficiency and the like. The investigation shows that the main body of the sludge after the semi-drying pretreatment is still high-heat-value combustion matter, which obviously cannot meet the requirement of large-batch treatment of low-heat-value sludge, and the secondary pollution of the environment is easily caused by the smoke generated by combustion, so that the incineration process of the sludge after the drying pretreatment is difficult to realize industrialized popularization and application all the time.
Therefore, it is necessary to provide a new sludge incineration treatment process, so as to reduce the cost of the sludge incineration treatment process, improve the energy saving and environmental protection properties of the process, and simultaneously, do not need to consume auxiliary fuel for blending combustion, but realize safe and stable self-sustaining combustion of the domestic sludge with low heat value after drying pretreatment. Thereby remarkably improving the industrial applicability of the domestic sludge combustion treatment process.
Disclosure of Invention
In view of the above technical background, the primary object of the present invention is to provide a process for incinerating domestic sludge, which can safely and stably complete self-sustaining combustion after drying pretreatment of domestic sludge with high water content, and which not only does not require adding auxiliary fuel in the incineration process, but also can fully utilize heat energy of a system, and finally can realize industrialized reduction treatment of domestic sludge.
Another object of the present invention is to provide an apparatus for the above-mentioned treatment process, so that the above-mentioned process can be efficiently implemented, further improving the industrial application value of the process.
The above object of the present invention is achieved by the following technical solutions:
firstly, the invention provides a self-sustaining incineration process of domestic sludge, which at least comprises the steps of first drying, second drying, crushing and incineration which are sequentially carried out; the method specifically comprises the following steps:
1) Firstly drying domestic sludge with the water content of 60-75% by using dry hot air to obtain sludge with the water content of 40-55% and moisture-carrying air;
2) The sludge with the water content of 40-55% obtained in the step 1) is subjected to secondary drying by using hot flue gas from incineration, so that sludge with the water content of not higher than 20% and wet flue gas are obtained;
3) Pulverizing the sludge with the water content not higher than 20% obtained in the step 2), mixing with the hot ash from the incineration, heating the pulverized sludge to a temperature close to the ignition point, and then self-sustaining incinerating the pulverized sludge in an incinerator at 850-950 ℃ to obtain high-temperature flue gas and high-temperature slag;
4) And 3) carrying out solid-gas separation on the high-temperature flue gas obtained in the step 3), returning the obtained gas as hot flue gas to the step 2) for the secondary drying, and returning the obtained solid as hot ash to the step 3) for mixing with the crushed sludge.
In the preferred treatment process of the invention, in order to fully recycle the heat energy from the incinerator, the dry air and the wet air obtained in 1) and the wet flue gas obtained in 2) are sequentially subjected to heat exchange and gradual temperature rise, and then returned to the first drying in 1) as dry hot air. In the first drying, the reduction of the water content of the sludge from more than 60% to 40% -55% is the optimal drying effect achieved by returning the hot dry air to 1) the first drying. When the drying amplitude is lower than the range, the exhaust temperature of the wet air and the wet flue gas is increased, and the waste heat loss is increased. If the temperature is higher than the range, the temperature of the mud after the second drying is too high or is not easy to control, and pyrolysis gas is separated out.
In the preferred treatment process of the invention, in order to avoid the generation of CO, H2 and other volatile combustible gases in the wet flue gas obtained in the step 2) as much as possible, the temperature of the sludge is controlled to be not higher than 120 ℃ in the step 2) of secondary drying and discharging.
In a preferred treatment process of the present invention, the pulverization of 3) is carried out by pulverizing sludge having a water content of not more than 20% to a particle size of not more than 5mm in order to improve the combustibility of the dried sludge. Therefore, the specific surface area of the sludge to be burned and dried can be remarkably increased, and the flammability of the sludge is further improved.
In the preferred treatment process, in order to fully recycle the heat energy from the incinerator, the high-temperature slag obtained in the step 3) is subjected to intense mixing heat exchange with air to obtain slag-containing hot air, and then the slag-containing hot air is subjected to solid-gas separation to obtain hot air and cooling slag; returning the hot air to 3) the incinerator for supporting combustion.
In the treatment process, 3) after sludge self-sustaining incineration occurs in the incinerator, the generated high-temperature flue gas contains ash and unburnt components; the invention fully recycles the solid in the high-temperature flue gas while recycling the gas in the high-temperature flue gas. Therefore, in the preferred scheme of the invention, the cyclone dust collector is adopted to perform solid-gas separation, so that 95% of solids in the high-temperature flue gas can be used as return materials to return to the dried sludge before incineration for heating, the temperature of the dried sludge is close to the ignition point, and simultaneously, the generated volatile combustible gas can also enter the incinerator for combustion along with the dried sludge.
In a more preferred treatment process according to the invention, in order to further ensure that the temperature of the sludge before entering the incinerator is close to the fire point, a part of the gas obtained in 4) is used for supplying heat to said crushed sludge.
Based on the self-sustaining incineration process of domestic sludge, the invention further provides a sludge harmless treatment process in situ arranged in a sewage treatment plant, which can treat sludge generated by sewage treatment in situ by utilizing the existing process of the sewage treatment plant, and the specific process flow is shown in figure 1 and comprises the following steps:
(1) sequentially performing primary drying, secondary drying, crushing and incineration treatment on sludge generated by sewage treatment of a sewage treatment plant; the method specifically comprises the following steps:
1) Firstly drying domestic sludge with the water content of 60-75% by using dry hot air to obtain sludge with the water content of 40-55% and moisture-carrying air;
2) The sludge with the water content of 40-55% obtained in the step 1) is subjected to secondary drying by using hot flue gas from incineration, so that sludge with the water content of not higher than 20% and wet flue gas are obtained;
3) Pulverizing the sludge with the water content not higher than 20% obtained in the step 2), mixing with the hot ash from the incineration, heating the pulverized sludge to a temperature close to the ignition point, and then self-sustaining incinerating the pulverized sludge in an incinerator at 850-950 ℃ to obtain high-temperature flue gas and high-temperature slag;
4) Sequentially exchanging heat between the dried air and the wet air obtained in the step 1) and the wet flue gas obtained in the step 2) to gradually raise the temperature, and returning the temperature as dry hot air to the step 1) for the first drying;
5) Carrying out solid-gas separation on the high-temperature flue gas obtained in the step 3), returning the obtained solid as hot ash to the step 3) and mixing the solid with the crushed sludge, and returning part of the obtained gas as hot flue gas to the step 2) for the secondary drying, wherein the other part of the obtained gas is used as a heat source to supply heat to the mixture of the hot ash and the crushed sludge;
(2) and (3) mixing the moisture-carrying air subjected to the step-by-step heat exchange with the moisture-carrying flue gas, washing with water to remove pollutants, and then introducing the mixture into an aeration tank of a sewage treatment plant for biological deodorization and treatment.
In the preferred scheme of the invention, the water washing step (2) is completed by using reclaimed water in the sewage treatment plant, and the water after water washing is introduced into a sewage water inlet of the sewage treatment plant.
The sludge innocent treatment process in situ provided by the sewage treatment plant can treat the produced sludge in situ in the sewage treatment plant, saves the sludge transportation cost, can fully utilize the existing devices and resources of the sewage treatment plant, such as a water washing device, reclaimed water, an aeration tank and the like, can realize the innocent treatment of incineration flue gas after the sludge is fully self-sustaining and can also improve the sewage treatment efficiency. The flue gas generated by burning the sludge is introduced into an aeration tank of a sewage treatment process, and the aeration can generate and maintain effective gas-liquid contact, and maintain a certain dissolved oxygen concentration in water under the condition that the biological oxidation continuously consumes oxygen, and generate sufficient mixing effect and circulating flow of the water in the aeration zone, and maintain a sufficient speed of liquid so as to enable biosolids in the water to be in a suspension state. The flue gas is introduced into the aeration tank, so that positive effects are generated on sewage treatment, the flue gas generated by burning the sludge is effectively treated, the emission of pollutants is reduced, particles, sulfur dioxide, hydrogen chloride, nitrogen oxides and other harmful substances dissolved in the sewage are removed from the flue gas, the effects of desulfurization, denitrification and dust removal are achieved, a large amount of heat is carried in the flue gas, the flue gas temperature is reduced, the purposes of controlling the flue gas pollutants and preventing the environment from being polluted are achieved, and a large amount of heat pollution is avoided.
In addition, the invention also provides a set of domestic sludge self-sustaining incineration equipment which comprises a feeding unit, a drying pretreatment unit, a crushing and heating unit and a self-sustaining incineration unit which are sequentially connected through pipelines;
the feeding unit is used for conveying domestic sludge with the water content of 60-75% to the drying pretreatment unit through a pipeline;
the drying pretreatment unit is used for carrying out staged drying treatment on the domestic sludge with the water content of 60% -75% until the water content is not higher than 20%; the drying pretreatment unit specifically comprises a first drying section and a second drying section which are sequentially connected through a pipeline; the first drying section is also connected with a gas heat exchange unit through a pipeline and is used for recycling waste heat of gas discharged from the first drying section and the second drying section through heat exchange;
the smashing and heating unit is used for smashing and further preheating the sludge subjected to the drying pretreatment to be close to the ignition point; the crushing and heating unit comprises a crushing device and a solid-gas separation device; the feed inlet of the crushing device is connected with the second drying section through a pipeline; the solid-gas separation device is connected with the self-sustaining incineration unit, the second drying section and the discharge port of the crushing device through pipelines respectively;
the self-sustaining incineration unit is used for incinerating the crushed and warmed sludge at 850-950 ℃; comprises an incinerator, a solid-gas heat exchange device and a solid-gas separation device which are communicated with each other; the incinerator is connected with a discharge port of the crushing device through a pipeline; the solid-gas heat exchange device is further connected with a blower; the solid-gas separation device is further provided with a slag discharging pipe.
The preferred equipment of the invention is further provided with a water washing unit and a biochemical aeration tank; the gas heat unit is used for discharging gas, the gas inlet of the gas heat unit is connected with the gas heat unit through a pipeline, and the gas outlet of the gas heat unit is connected with the biochemical aeration tank through a pipeline.
In the preferred device of the invention, the feeding unit is provided with an extrusion device for conveying materials to the drying pretreatment unit in an extrusion mode.
In the preferred device of the invention, the positions of the feed inlet and the air inlet of the first drying section are suitable for forming countercurrent heat exchange in the first drying section so as to improve the heat exchange efficiency.
In the preferred equipment of the invention, the gas heat exchange unit comprises a blower, a first-stage heat exchange device and a second-stage heat exchange device which are sequentially connected in series, wherein the blower is used for generating dry air, the first-stage heat exchange device is used for exchanging heat between the dry air and gas exhausted by the first drying section, and the second-stage heat exchange device is used for exchanging heat between the gas heated by the first-stage heat exchange and the gas exhausted by the second drying section; the second-stage heat exchange device is further connected with the first drying section through a pipeline, and dry hot air heated after the second-stage heat exchange is sent into the first drying section.
In the preferred equipment of the invention, the second drying section is a variable-section hearth, and the section of the hearth gradually becomes smaller along with the trend of the airflow and gradually becomes larger along with the trend of the sludge, so that countercurrent heat exchange in the second drying section is formed, and the heat exchange efficiency can be improved.
In the equipment of the invention, the solid-gas separation device of the crushing and heating unit and the self-sustaining incineration unit is a cyclone dust collector.
In the preferred equipment of the invention, in the crushing and heating unit, a communicated flue gas pipeline is also arranged between the crushing device and the solid-gas separation device and is used for introducing part of hot flue gas from the solid-gas separation device into a discharging section of the crushing device.
When the equipment is used for continuously carrying out sludge incineration treatment, a feeding unit sends sludge into a first drying section, a gas heat exchange unit connected with the first drying section inputs dry hot air into the first drying section, the sludge is dried by the dry hot air in the first drying section until the water content is 40-55%, meanwhile, moisture is evaporated to enable the dry hot air to be changed into wet air, the wet air is discharged from the first drying section and then enters the gas heat exchange unit through a pipeline to exchange heat with the dry air for cooling, and semi-dried sludge with the water content of 40-55% is sent into a second drying section through the pipeline; the high-temperature flue gas generated by the incinerator of the self-sustaining incineration unit is firstly divided into hot flue gas and hot ash by a solid-gas separation device of the crushing and heating unit after being discharged from the top of the incinerator, the hot flue gas is sent into a second drying section by a pipeline, the sludge is further dried by the hot flue gas in the second drying section until the water content is not higher than 20%, meanwhile, water is evaporated to form wet flue gas, the temperature of the sludge at the outlet of the second drying section is controlled to be lower than 120 ℃ so as to prevent volatile combustible gas such as CO and/or H2 from being generated in the drying process and entering the wet flue gas; the wet-carrying flue gas is discharged from the second drying section and enters a gas heat exchange unit through a pipeline, the dry air subjected to heat exchange and temperature rise with the wet-carrying air is further subjected to heat exchange with the wet-carrying flue gas, and the wet-carrying flue gas is cooled and enters a flue gas post-treatment device, such as a water washing unit and an aeration unit, together with the cooled wet-carrying air through the pipeline; in the gas heat exchange unit, the temperature of the dry air which is subjected to heat exchange with the wet air and the wet flue gas in sequence is raised step by step to form dry hot air, and the dry hot air is introduced into the first drying section for drying after exiting the gas heat exchange unit; the sludge with the water content not higher than 20% obtained in the second drying section is sent into a crushing and heating unit through a pipeline, crushed in a crushing device until the particle size is smaller than 5mm, then mixed with hot ash separated by a solid-gas separation device, heated to be close to the ignition point, and then enters an incinerator together with the hot ash through the pipeline, and the crushed sludge is subjected to self-sustaining incineration in the incinerator at 850-950 ℃ to generate high-temperature slag and high-temperature flue gas; the high-temperature flue gas is recycled in the mode, high-temperature slag enters a solid-gas heat exchange device through a pipeline to exchange heat with air provided by a blower to obtain slag-containing hot air, and the slag-containing hot air is discharged out of the solid-gas heat exchange device and enters a solid-gas separation device through the pipeline to be separated to obtain hot air and cooling slag; hot air enters the incinerator through a pipeline to support combustion, and cooling slag is discharged out of the system through a slag discharging pipe.
The beneficial effects of the invention are mainly represented in the following aspects:
1. can realize self-sustaining combustion after drying domestic sludge
According to the domestic sludge self-sustaining incineration process and equipment provided by the invention, the normal-temperature domestic sludge with the water content of 60% -75% is dried step by step and heated, so that the water content of the sludge is not higher than 20% before entering the incinerator, the temperature is close to self-ignition point, the heat value is close to 2900kcal/kg, and meanwhile, the specific surface area of the sludge is increased through crushing, so that the sludge enters the incinerator and self-sustaining combustion can be carried out at 850 ℃ -950 ℃ without adding any auxiliary fuel.
2. Can fully recycle waste heat and realize cascade utilization of energy
In the gradual drying and heating process of the sludge, the process and the equipment fully utilize the self heat in the system through step-type heat exchange, and particularly recover the latent heat of the water vapor in the wet flue gas and the wet air. In the whole process, the incinerator is the highest point of system temperature, heat carried by high-temperature flue gas from the incinerator reversely flows back to the second drying section and the first drying section step by step through drying and heat exchange, and the step-by-step reduced temperature of the flue gas fully meets the step-by-step heating requirements of the two drying sections.
3. The hot ash returning material is fully utilized to heat the dried sludge to be close to the ignition point before entering the incinerator, so that the self-sustaining combustion of the dried sludge can be ensured to stably occur.
The invention takes the solid hot ash contained in the high-temperature flue gas as return material alone, and heats the dried sludge finally before entering the incinerator, and the hot ash is mixed with the crushed sludge particles in a solid form, so that the temperature of the sludge particles is quickly close to the ignition point, and volatile gases can be fully recycled into the incinerator for combustion, thereby avoiding heat value loss, avoiding impact on the furnace temperature and ensuring stable combustion of the incinerator. The recycling of the heat of the returned materials provides vital assistance and guarantee for self-sustaining incineration of the sludge after the sludge enters the incinerator. The assistance and the guarantee are completely from the full utilization of the heat in the system, and the energy and materials outside the system are not required to be consumed additionally.
4. Can be combined with sewage treatment process to improve industrial application value
When the process system disclosed by the invention is arranged in situ in a sewage treatment plant, the industrial application value of the process system can be further improved. The process and the equipment can treat sludge generated in a factory in situ of a sewage treatment plant or construct the sewage treatment plant nearby, can save the transportation cost of a large amount of sludge for outward transportation treatment, can well utilize the existing equipment and resources of the sewage treatment plant, treat flue gas through a gas washing tower, use reclaimed water of the sewage treatment plant, discharge the water into a sewage inlet of the sewage treatment plant, discharge the flue gas into an aeration tank, realize the bidirectional promotion of sewage treatment and sludge treatment, and finally realize the effective reduction, harmless and recycling treatment of domestic sludge.
Drawings
FIG. 1 is an overall process flow diagram of an embodiment of the present invention. Wherein, the triangular arrow represents the trend of the solid material; broken line arrows represent the gas material trend.
Fig. 2 is a schematic diagram of the overall composition of the apparatus employed in the embodiments of the present invention.
Fig. 3 is a schematic diagram of the overall composition of the apparatus employed in a preferred embodiment of the present invention.
Reference numerals illustrate:
1-a sludge bin, 2-an extruder, 3-a first drying section, 31-a first sludge inlet, 32-a sludge conveyor belt, 33-a first sludge outlet, 34-a hot dry air inlet, 35-a wet air carrying outlet, 4-a second drying section, 41-a second sludge inlet, 42-a second sludge outlet, 43-a flue gas inlet, 44-a wet flue gas carrying outlet, 45-a sludge conveying device, 5-a spiral crushing conveyor, 6-a flue gas cyclone, 61-a high temperature flue gas inlet, 62-a hot flue gas outlet, 63-a hot ash outlet, 64-a hot flue gas shunt tube, 65-a draught fan, 66-a regulating valve, 7-a return valve, 71-a return bin, 8-an incinerator, 81-a high temperature flue gas outlet, 82-a hot air inlet, 83-a dried sludge inlet, 9-a wind distribution plate, 10-a slag discharge pipe, 11-a valve, 12-a forced air flow heat exchanger, 13-an air cyclone, 131-a slag discharge port, 132-a hot air outlet, 14-combustion blower, 15-blower, 16-a first-stage heat pipe heat exchanger, 17-a second heat pipe heat exchanger, a heat pipe heat exchanger, 18-a heat pipe washer, and a draught fan.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be further described in detail with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the invention.
The invention provides a device and a method for drying and incinerating sludge in a sewage treatment plant so as to achieve the aim of sludge reduction.
The whole composition of the device is shown in figure 2, and is provided with a sludge bin 1, and an extruder 2 for preparing sludge into sludge strips is arranged below the sludge bin 1. The outlet of the extruder 2 is connected with the first drying section 3. The first drying stage 3 is provided with a first sludge inlet 31, a sludge conveyor 32, a first sludge outlet 33, a hot dry air inlet 34 and a humid air outlet 35. The moisture-carrying air outlet 35 is connected with the first-stage heat pipe heat exchanger 16 through a pipeline, and the outlet of the first-stage heat pipe heat exchanger 16 is connected with the water scrubber 18 through a pipeline. The dry hot air inlet 34 is connected with the second-stage heat pipe exchanger 17, the first-stage heat pipe exchanger 16 and the drying blower 15 in sequence through pipes. The dry air pipeline connected with the drying blower 15 is connected with the wet air pipeline led out from the wet air outlet 35 through the first-stage heat pipe exchanger 16 to perform first-stage heat exchange, the temperature of the wet air is reduced below the dew point, and the sensible heat of the wet air and the vaporization latent heat of the water vapor are recovered. The second drying section 4 is provided with a second sludge inlet 41, a second sludge outlet 42, a flue gas inlet 43, a wet flue gas outlet 44 and a sludge transfer device 45. The first sludge outlet 33 of the first drying stage 3 is connected to the second sludge inlet 41 of the second drying stage 4 by means of a pipe. The second drying section is a variable-section hearth, and the second sludge inlet 42 and the smoke inlet 43 are respectively arranged at two ends of the hearth to form countercurrent heat exchange, so that the heat exchange efficiency is improved. The wet flue gas carrying outlet 44 is connected to the second stage heat pipe exchanger 17. The wet flue gas carrying pipeline led out by the wet flue gas carrying outlet 44 is connected with the dry air pipeline led out by the first-stage heat pipe heat exchanger 16 through the second-stage heat pipe heat exchanger 17 to carry out second-stage heat exchange, so that the temperature of the wet flue gas is reduced below the dew point, and the sensible heat of the wet flue gas and the vaporization latent heat of water vapor are recovered. The second sludge outlet 42 of the second drying section 4 is connected with the spiral crushing conveyor 5 through a pipeline, and the dried sludge is crushed into powder with the particle size not more than 5mm in the spiral crushing conveyor 5. The outlet of the spiral crushing conveyor 5 is connected with a return valve 7 through a pipeline, in the return valve 7, crushed sludge powder is mixed with hot ash returned by the flue gas cyclone dust collector 6, the mixture is heated by the hot ash, the temperature is raised to be close to the ignition point of the sludge powder, the mixture enters the incinerator 8 for self-sustaining combustion, and volatile combustible gas generated simultaneously also enters the incinerator 8 for combustion. The top of the incinerator 8 is provided with a high-temperature flue gas outlet 81, the bottom is provided with a hot air inlet 82, and the middle is provided with a dried sludge inlet 83. The high-temperature flue gas outlet 81 is connected with the high-temperature flue gas inlet 61 at the upper part of the flue gas cyclone 6, the hot flue gas outlet 62 of the flue gas cyclone 6 is connected with the flue gas inlet 43 of the second drying section 4, and the hot ash outlet 63 of the flue gas cyclone 6 is connected with the return valve 7. The lower part of the incinerator 8 is provided with an air distribution plate 9, the air distribution plate 9 is provided with a slag discharging pipe 10, the slag discharging pipe 10 is connected with an intensified airflow heat exchanger 12 through a pipeline with a valve 11, and the intensified airflow heat exchanger 12 is further connected with a combustion-supporting blower 14 through a pipeline. Air is blown into the intensified air flow heat exchanger 12 through the combustion-supporting blower 14, exchanges heat with high-temperature slag from the slag discharging pipe 10, then enters the air cyclone 13 to realize solid-gas separation, the air cyclone 13 is provided with a slag discharging port 131 and a hot air outlet 132, cooled slag is discharged out of the system through the slag discharging port 131, and hot air enters the incinerator 8 through a pipeline to support combustion.
In some preferred embodiments, as shown in fig. 3, in order to further ensure that the temperature of the sludge before entering the incinerator is close to the fire point, a return bin 71 may be provided below the return valve 7 for holding hot soot from the flue gas cyclone 6 and crushed sludge powder from the spiral crushing conveyor 5, while a hot flue gas shunt 64 is provided on the conduit outside the hot flue gas outlet 62 of the flue gas cyclone 6 for connecting the return bin 71. Such a portion of the hot flue gas from the flue gas cyclone 6, after exiting the hot flue gas outlet 62, may be directed into a return bin 71 for further heating of the sludge powder. In a more preferred scheme, an induced draft fan 65 and a regulating valve 66 can be further arranged on the hot flue gas shunt pipe 64 and used for regulating and controlling the hot flue gas quantity introduced into the return bin 71.
The specific type of the incinerator 8 in the present invention is not particularly limited, and may be any of a grate type incinerator, a fluidized bed incinerator, a multiple hearth type incinerator, and a rotary kiln type incinerator.
The flue gas cyclone 6 and the air cyclone 13 in the present invention may be the same type and specification of cyclone. The cyclone dust collector has the advantages of long service life, easy installation and maintenance, small volume, simple structure and low equipment cost, is suitable for purifying dust with high density and particle size of more than 5 mu m, adopts special high-temperature resistant materials to realize higher temperature resistance, and can be used for purifying flue gas containing high-abrasion dust after the abrasion-resistant lining is arranged in the dust collector.
The water of the gas washing tower is from reclaimed water in the sewage treatment process, and after the gas washing process is completed, muddy water enters a water inlet tank of a sewage plant, so that the condition of the sewage plant is fully utilized, and the cost is reduced. The purification principle of treating smoke with water is mainly to separate pollutants by immersing and dissolving. The specific process comprises dispersing the pollutants in the air flow by mechanical equipment, adsorbing the pollutants by water mist in the air flow, loosening the pollutants by chemical and physical actions by utilizing the self-cleaning action of water, combining the pollutants with water to form a residue, and collecting and removing the residue by the equipment. The discharge port of the gas washing tower is arranged at the top of the tower body, and clean gas can be directly discharged into the atmosphere after the flue gas is detected. The pollutant in the flue gas is removed through the gas washing tower, the method is simple and convenient, and the recycling of the water in the sewage plant is realized.
In some embodiments, the scrubber consists of a tower body, a packing layer, a spray system, an inlet pipe, an outlet pipe, an exhaust port, etc., from which flue gas enters the tower body, and when passing through the packing layer, the flue gas contacts the liquid and the contaminants are absorbed. The packing layer increases the contact area, so that the flue gas is fully contacted with the liquid, and the purification efficiency is improved. The spraying system uniformly sprays the liquid on the packing layer to enable the liquid to be fully contacted with the flue gas, thereby realizing the absorption of pollutants.
In some embodiments, the induced draft fan 19 may be replaced with a blast aerator system consisting of a blower, an air delivery conduit, and an aerator. In the implementation process, the flue gas is introduced through a blower of the blower aerator system, and is diffused along the air conveying pipeline and enters the aeration tank through the aerator, so that the flue gas is fully contacted with the sewage. The aerator forcedly transfers oxygen in air or flue gas into the aeration tank to be diffused by the aerator equipment, so that the activated sludge system keeps enough dissolved oxygen, and the activated sludge is always in a suspension state and fully contacts and mixes with organic matters and dissolved oxygen in sewage to complete the organic process of microbial degradation. In some embodiments, the aerator adopts a membrane type microporous aerator, the air blower conveys the flue gas to the aerator arranged at the bottom of the aeration tank through an air conveying pipeline, so that the flue gas forms bubbles with the bubble diameter of 1.5-3.0mm, the membrane type microporous aerator is made of polypropylene into a base, the microporous aeration membrane is made of synthetic rubber, the membrane is provided with holes which are concentrically and circularly arranged, and the synthetic rubber can be thermoplastic polyurethane rubber or silica gel. In the implementation process, when the membrane type microporous aerator is adopted, the membrane type microporous aerator is a base made of polypropylene, and microporous aeration membranes, such as rubber aeration membranes and silica gel aeration membranes, are made of synthetic rubber, wherein the membrane is provided with concentric circular holes. When aeration is performed, air enters between the aerator diaphragm and the base through the vent holes on the base, so that the aerator diaphragm slightly bulges, and the holes are opened, thereby achieving the purpose of aeration diffusion. After the air supply pressure is stopped to disappear, the holes are closed under the elastic action of the aerator diaphragm, and the aerator diaphragm is compacted on the aerator base under the action of water pressure, so that the holes are not blocked. The diameter of the air bubble generated by the aerator is 1.5-3.0mm, a small amount of dust can pass through the holes, and the aerator can not be blocked, and air purifying equipment is not needed.
By utilizing the device to carry out the sludge drying and incinerating process, the sludge with 60% -75% of water is fed into the sludge bin, and firstly enters the first drying section 3, and the sludge is dried in the first drying section 3 by utilizing hot dry air until the water content reaches 40% -55%, so that moisture-carrying air is formed. And drying the sludge with the water content of 40-55% to the water content of 20% in the second drying section 4 by utilizing the high-temperature flue gas waste heat of the incinerator 8. Countercurrent heat exchange is adopted in the second drying section 4, and in order to avoid evaporating volatile combustible gases such as CO, H2 and the like as far as possible, the sludge temperature at the second sludge outlet 42 of the second drying section 4 is controlled to be less than 120 ℃. In order to better control the gas components evaporated in the second drying section 4 not to contain volatile combustible gases such as CO, H2 and the like, ensure that only water is evaporated, a smoke detection device can be arranged in the second drying section 4 to monitor whether the volatile combustible gases such as CO, H2 and the like are generated or not, and the drying temperature is regulated and controlled by combining the monitoring result. The desiccated sludge with the water content of 20% output by the second desiccation section 4 is crushed into powder by a spiral crushing conveyor and then is mixed with hot ash discharged by a flue gas cyclone dust collector 6 in a return valve 7, the desiccated sludge which is heated to be close to the ignition point is sent into an incinerator 8 from the return valve 7, self-sustaining combustion is carried out at 850-950 ℃, and the retention time of the produced high-temperature flue gas in the temperature interval is more than 2 seconds, so that the high-temperature flue gas and the high-temperature slag are generated. And the hot flue gas obtained by separating the high-temperature flue gas by the flue gas cyclone dust collector 6 flows back to the second drying section 4, and the wet flue gas is formed after drying is completed. The dry air and the wet air formed by the first drying section 3 and the wet flue gas formed by the second drying section 4 are subjected to first-stage heat exchange and second-stage heat exchange in sequence, and the obtained dry hot air is returned to the first drying section 3 for drying. The wet carrying air cooled by the first stage heat exchange and the wet carrying flue gas cooled by the second stage heat exchange are mixed and then enter a gas washing tower 18, smoke dust and pollutants are removed by using a spray water washing mode, and then are discharged into an aeration tank of a sewage treatment plant through an induced draft fan 19 for biological deodorization and treatment. The gas washing tower 18 refers to the reclaimed water of the sewage treatment plant, and the effluent of the gas washing tower 18 is sent to the water inlet of the sewage treatment plant, so that the existing resources of the sewage treatment plant are fully utilized.
According to the embodiment of the invention, the domestic sludge is treated by combustion in an in-situ distribution mode in the sewage treatment plant, and the flue gas generated by combustion is introduced into the gas washing tower of the sewage treatment plant, so that pollutants in the flue gas are removed, the gas washing effect is achieved, and the emission of pollutants such as particulate matters, sulfur dioxide, nitrogen oxides, hydrogen chloride, dioxin and the like is reduced. By adopting the embodiment of the invention, the domestic sludge can be directly combusted in the sewage treatment plant without mixing and combusting coal, domestic garbage and other auxiliary materials, the operation cost is low, the environment of the sewage treatment plant is fully utilized, the transportation process is avoided, the cost is reduced, the secondary pollution to the environment is avoided, the occupied area is reduced, and the environmental pollution is reduced. In the implementation process of the invention, the incinerator burns and dries the sludge and then converts the sludge into water, carbon dioxide, a small amount of nitrogen oxides, a small amount of sulfur oxides and ash, and the ash can be used as a building material, thereby realizing the recycling and harmless of low-heat-value sludge combustion. The invention sets the combustion temperature of the incinerator to 850-950 ℃, can realize harmless treatment of domestic sludge, can stably catch fire in the incinerator which only takes the dried sludge as the raw material without adding any auxiliary fuel, and can burn out efficiently and realize the standard emission of NOx. The device has compact structure and small occupied area, fully utilizes the waste heat of the flue gas in the system, heats and dries the sludge to be combusted through the waste heat of the flue gas, avoids the waste of heat and improves the heat utilization rate. The incinerated dust slag can be used as building materials or paving, and the technical problem that the existing process cannot process the sludge with high water content at low cost is solved. The method has the advantages of simple process flow and high system safety, and realizes reduction, harmlessness and recycling to the greatest extent. The carbon content of the sludge combustion ash slag in the process is lower than 1%.
Example 1
The method comprises the steps of (1) treating domestic sludge generated by sewage from a sewage treatment plant, wherein the initial water content is 75%, and sequentially drying for the first time to obtain sludge with the water content of 55% and moisture-carrying air; the obtained sludge with the water content of 55% is subjected to secondary drying by using the incineration hot flue gas to obtain sludge with the water content of 20% and wet flue gas; the obtained sludge is crushed and then mixed with hot ash, the crushed sludge is heated to be close to the ignition point, and then the crushed sludge is fed into an incinerator for self-sustaining incineration at 850 ℃ to obtain high-temperature flue gas and high-temperature slag; the heat exchange of the dry air, the wet air and the wet flue gas is sequentially carried out, the temperature is increased step by step, and the dry air, the wet air and the wet flue gas are returned to the primary drying unit as dry hot air; and (3) carrying out solid-gas separation on the high-temperature flue gas, returning the obtained solid as hot ash to the incinerator to be mixed with the crushed sludge, wherein one part of the obtained gas is used for secondary drying, and the other part of the obtained gas is used as a heat source to provide heat for the mixture of the hot ash and the sludge. Mixing the moisture-carrying air subjected to step-by-step heat exchange with the moisture-carrying flue gas, washing with water to remove pollutants, and then introducing the mixture into an aeration tank of a sewage treatment plant for biological deodorization and treatment. The carbon content of the sludge combustion ash is 0.8%.
Example 2
The method comprises the steps of (1) treating domestic sludge No. 2 generated by sewage from a sewage treatment plant, sequentially drying the domestic sludge with an initial water content of 68% for the first time to obtain sludge with a water content of 48% and moisture-carrying air; the obtained sludge with the water content of 48% is subjected to secondary drying by using the incineration hot flue gas to obtain sludge with the water content of 15% and wet flue gas; the obtained sludge is crushed and then mixed with hot ash, the crushed sludge is heated to be close to the ignition point, and then the crushed sludge is fed into an incinerator for self-sustaining incineration at 900 ℃ to obtain high-temperature flue gas and high-temperature slag; the heat exchange of the dry air, the wet air and the wet flue gas is sequentially carried out, the temperature is increased step by step, and the dry air, the wet air and the wet flue gas are returned to the primary drying unit as dry hot air; and (3) carrying out solid-gas separation on the high-temperature flue gas, returning the obtained solid as hot ash to the incinerator to be mixed with the crushed sludge, wherein one part of the obtained gas is used for secondary drying, and the other part of the obtained gas is used as a heat source to provide heat for the mixture of the hot ash and the sludge. Mixing the moisture-carrying air subjected to step-by-step heat exchange with the moisture-carrying flue gas, washing with water to remove pollutants, and then introducing the mixture into an aeration tank of a sewage treatment plant for biological deodorization and treatment. The carbon content of the sludge combustion ash is 0.6%.
Example 3
The method comprises the steps of (1) treating domestic sludge No. 3 generated by sewage from a sewage treatment plant, wherein the initial water content is 60%, and sequentially drying for the first time to obtain sludge with the water content of 40% and moisture-carrying air; the obtained sludge with the water content of 40% is subjected to secondary drying by using the incineration hot flue gas to obtain sludge with the water content of 10% and wet flue gas; the obtained sludge is crushed and then mixed with hot ash, the crushed sludge is heated to be close to the ignition point, and then the crushed sludge is fed into an incinerator for self-sustaining incineration at 950 ℃ to obtain high-temperature flue gas and high-temperature slag; the heat exchange of the dry air, the wet air and the wet flue gas is sequentially carried out, the temperature is increased step by step, and the dry air, the wet air and the wet flue gas are returned to the primary drying unit as dry hot air; and (3) carrying out solid-gas separation on the high-temperature flue gas, returning the obtained solid as hot ash to the incinerator to be mixed with the crushed sludge, wherein one part of the obtained gas is used for secondary drying, and the other part of the obtained gas is used as a heat source to provide heat for the mixture of the hot ash and the sludge. Mixing the moisture-carrying air subjected to step-by-step heat exchange with the moisture-carrying flue gas, washing with water to remove pollutants, and then introducing the mixture into an aeration tank of a sewage treatment plant for biological deodorization and treatment. The carbon content of the sludge combustion ash is 0.5%.
Claims (17)
1. The domestic sludge self-sustaining incineration process is characterized by at least comprising the steps of sequentially performing primary drying, secondary drying, crushing and incineration; the method specifically comprises the following steps:
1) Firstly drying domestic sludge with the water content of 60-75% by using dry hot air to obtain sludge with the water content of 40-55% and moisture-carrying air;
2) The sludge with the water content of 40-55% obtained in the step 1) is subjected to secondary drying by using hot flue gas from incineration, so that sludge with the water content of not higher than 20% and wet flue gas are obtained;
3) Pulverizing the sludge with the water content not higher than 20% obtained in the step 2), mixing with the hot ash from the incineration, heating the pulverized sludge to a temperature close to the ignition point, and then self-sustaining incinerating the pulverized sludge in an incinerator at 850-950 ℃ to obtain high-temperature flue gas and high-temperature slag;
4) And 3) carrying out solid-gas separation on the high-temperature flue gas obtained in the step 3), returning the obtained gas as hot flue gas to the step 2) for the secondary drying, and returning the obtained solid as hot ash to the step 3) for mixing with the crushed sludge.
2. The process of claim 1, wherein: and (2) sequentially exchanging heat between the dried air and the wet air obtained in the step (1) and the wet flue gas obtained in the step (2) to gradually raise the temperature, and returning the heated air as dry hot air to the step (1) for the first time of drying.
3. The process of claim 1, wherein: 3) The crushing is to crush the sludge with the water content not higher than 20% to the grain size not larger than 5mm.
4. The process of claim 1, wherein: and controlling the temperature of the sludge in the second drying discharging process of 2) to be not higher than 120 ℃.
5. The process of claim 1, wherein: carrying out intensive mixing heat exchange on the high-temperature slag obtained in the step 3) and air to obtain slag-containing hot air, and then carrying out solid-gas separation on the slag-containing hot air to obtain hot air and cooling slag; returning the hot air to 3) the incinerator for supporting combustion.
6. The process of claim 1, wherein: and 4) using part of the obtained gas in the step 4) to supply heat for the crushed sludge.
7. The process of claim 1, wherein: the solid-gas separation is carried out by a cyclone dust collector.
8. A sludge innocent treatment process for in-situ setting of a sewage treatment plant comprises the following steps:
(1) sequentially performing primary drying, secondary drying, crushing and incineration treatment on sludge generated by sewage treatment of a sewage treatment plant; the method specifically comprises the following steps:
(1) Firstly drying domestic sludge with the water content of 60-75% by using dry hot air to obtain sludge with the water content of 40-55% and moisture-carrying air;
(2) The sludge with the water content of 40-55% obtained in the step (1) is subjected to secondary drying by using hot flue gas from incineration, so that sludge with the water content of not higher than 20% and wet flue gas are obtained;
(3) Pulverizing the sludge with the water content not higher than 20% obtained in the step (2), mixing with the hot ash from the incineration, heating the pulverized sludge to a temperature close to the ignition point, and then self-sustaining incinerating the pulverized sludge in an incinerator at 850-950 ℃ to obtain high-temperature flue gas and high-temperature slag;
(4) Sequentially exchanging heat between the dried air and the wet air obtained in the step (1) and the wet flue gas obtained in the step (2), and then gradually heating the wet air and the wet flue gas to be used as dry hot air to return to the step (1) for the first time for drying;
(5) Carrying out solid-gas separation on the high-temperature flue gas obtained in the step (3), returning the obtained solid as hot ash (3) to be mixed with the crushed sludge, returning one part of the obtained gas as hot flue gas (2) for the secondary drying, and supplying heat to the mixture of the hot ash and the crushed sludge as a heat source;
(2) and (3) mixing the moisture-carrying air subjected to the step-by-step heat exchange with the moisture-carrying flue gas, washing with water to remove pollutants, and then introducing the mixture into an aeration tank of a sewage treatment plant for biological deodorization and treatment.
9. The process of claim 8, wherein: (2) the water washing is completed by using reclaimed water in the sewage treatment plant, and the water after water washing is introduced into a sewage water inlet of the sewage treatment plant.
10. The apparatus for the self-sustaining incineration process of domestic sludge as claimed in claim 1, comprising a feeding unit, a drying pretreatment unit, a crushing and heating unit and a self-sustaining incineration unit which are sequentially connected through pipelines;
the feeding unit is used for conveying domestic sludge with the water content of 60-75% to the drying pretreatment unit through a pipeline;
the drying pretreatment unit is used for carrying out staged drying treatment on the domestic sludge with the water content of 60% -75% until the water content is not higher than 20%; the drying pretreatment unit specifically comprises a first drying section and a second drying section which are sequentially connected through a pipeline; the first drying section is also connected with a gas heat exchange unit through a pipeline and is used for recycling waste heat of gas discharged from the first drying section and the second drying section through heat exchange;
the smashing and heating unit is used for smashing and further preheating the sludge subjected to the drying pretreatment to be close to the ignition point; the crushing and heating unit comprises a crushing device and a solid-gas separation device; the feed inlet of the crushing device is connected with the second drying section through a pipeline; the solid-gas separation device is connected with the self-sustaining incineration unit, the second drying section and the discharge port of the crushing device through pipelines respectively;
the self-sustaining incineration unit is used for incinerating the crushed and warmed sludge at 850-950 ℃; comprises an incinerator, a solid-gas heat exchange device and a solid-gas separation device which are communicated with each other; the incinerator is connected with a discharge port of the crushing device through a pipeline; the solid-gas heat exchange device is further connected with a blower; the solid-gas separation device is further provided with a slag discharging pipe.
11. The apparatus as claimed in claim 10, wherein: the device is further provided with a water washing unit and a biochemical aeration tank; the gas heat unit is used for discharging gas, the gas inlet of the gas heat unit is connected with the gas heat unit through a pipeline, and the gas outlet of the gas heat unit is connected with the biochemical aeration tank through a pipeline.
12. The apparatus as claimed in claim 10, wherein: the feeding unit is provided with an extrusion device for conveying materials to the drying pretreatment unit in an extrusion mode.
13. The apparatus as claimed in claim 10, wherein: the positions of the feed inlet and the air inlet of the first drying section are suitable for forming countercurrent heat exchange in the first drying section, so that the heat exchange efficiency is improved.
14. The apparatus as claimed in claim 10, wherein: the gas heat exchange unit comprises a blower, a first-stage heat exchange device and a second-stage heat exchange device which are sequentially connected in series, wherein the blower is used for generating dry air, the first-stage heat exchange device is used for exchanging heat between the dry air and gas exhausted from the first drying section, and the second-stage heat exchange device is used for exchanging heat between the gas heated by the first-stage heat exchange and the gas exhausted from the second drying section; the second-stage heat exchange device is further connected with the first drying section through a pipeline, and dry hot air heated after the second-stage heat exchange is sent into the first drying section.
15. The apparatus as claimed in claim 10, wherein: the second drying section is a variable-section hearth, and the section of the hearth gradually becomes smaller along with the trend of air flow and gradually becomes larger along with the trend of sludge, so that countercurrent heat exchange in the second drying section is formed.
16. The apparatus as claimed in claim 10, wherein: the solid-gas separation device of the crushing and heating unit and the self-sustaining incineration unit is a cyclone dust collector.
17. The apparatus as claimed in claim 10, wherein: in the crushing and heating unit, a communicated flue gas pipeline is further arranged between the crushing device and the solid-gas separation device and used for introducing part of hot flue gas from the solid-gas separation device into a discharging section of the crushing device.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311395320.7A CN117128523B (en) | 2023-10-25 | 2023-10-25 | Domestic sludge self-sustaining incineration process and equipment |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311395320.7A CN117128523B (en) | 2023-10-25 | 2023-10-25 | Domestic sludge self-sustaining incineration process and equipment |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN117128523A true CN117128523A (en) | 2023-11-28 |
| CN117128523B CN117128523B (en) | 2023-12-22 |
Family
ID=88861390
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202311395320.7A Active CN117128523B (en) | 2023-10-25 | 2023-10-25 | Domestic sludge self-sustaining incineration process and equipment |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN117128523B (en) |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE2404067A1 (en) * | 1974-01-29 | 1975-08-07 | Ver Kesselwerke Ag | Incinerator for refuse and clarification sludge - prepares sludge separately by drying and grinding for burning |
| KR200178486Y1 (en) * | 1999-10-07 | 2000-04-15 | 서화두 | Drying melting process for waste and sludge |
| CN201606882U (en) * | 2010-01-15 | 2010-10-13 | 张圣东 | High-efficiency incinerator with circulating fluidized grates |
| CN105948459A (en) * | 2016-05-19 | 2016-09-21 | 山东齐盛机电工程有限公司 | Method using drying and incineration to treat sludge |
| CN110043909A (en) * | 2019-04-21 | 2019-07-23 | 温州兴南环保科技有限公司 | A kind of chemical engineering sludge burning process |
| CN110734209A (en) * | 2019-10-22 | 2020-01-31 | 浙江环兴机械有限公司 | Operation method of industrial solid waste and sludge rotary kiln co-processing integrated device |
| CN116554931A (en) * | 2023-05-11 | 2023-08-08 | 中鹏未来有限公司 | Domestic garbage carbonization gasification hydrogen production process |
-
2023
- 2023-10-25 CN CN202311395320.7A patent/CN117128523B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE2404067A1 (en) * | 1974-01-29 | 1975-08-07 | Ver Kesselwerke Ag | Incinerator for refuse and clarification sludge - prepares sludge separately by drying and grinding for burning |
| KR200178486Y1 (en) * | 1999-10-07 | 2000-04-15 | 서화두 | Drying melting process for waste and sludge |
| CN201606882U (en) * | 2010-01-15 | 2010-10-13 | 张圣东 | High-efficiency incinerator with circulating fluidized grates |
| CN105948459A (en) * | 2016-05-19 | 2016-09-21 | 山东齐盛机电工程有限公司 | Method using drying and incineration to treat sludge |
| CN110043909A (en) * | 2019-04-21 | 2019-07-23 | 温州兴南环保科技有限公司 | A kind of chemical engineering sludge burning process |
| CN110734209A (en) * | 2019-10-22 | 2020-01-31 | 浙江环兴机械有限公司 | Operation method of industrial solid waste and sludge rotary kiln co-processing integrated device |
| CN116554931A (en) * | 2023-05-11 | 2023-08-08 | 中鹏未来有限公司 | Domestic garbage carbonization gasification hydrogen production process |
Also Published As
| Publication number | Publication date |
|---|---|
| CN117128523B (en) | 2023-12-22 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| KR100935446B1 (en) | Method of device for high water content of drying and carbonizing | |
| CN109945211B (en) | Burning treatment method and system for semi-coke pyrolysis waste gas and waste liquid | |
| CN112111302B (en) | Low-order material gasification combustion and flue gas pollutant control integrated process and device and application | |
| CN113587117B (en) | System and method for innocent treatment of sludge | |
| WO2013166992A1 (en) | Solid waste incinerator without emission of flue gas and incinerator body | |
| JP2008275179A (en) | Combustion system of flame retardant high-viscosity waste such as pcb | |
| CN107721112B (en) | Municipal sludge drying pyrolysis gasification self-sustaining incineration system | |
| CN112062435B (en) | Oil sludge pyrolysis treatment device and process thereof | |
| KR100935447B1 (en) | High water content of drying device | |
| CN113234490A (en) | Gasification-based sludge comprehensive utilization system and treatment method | |
| CN117128523B (en) | Domestic sludge self-sustaining incineration process and equipment | |
| CN111256147A (en) | Household garbage pyrolysis gasification incineration grate furnace and treatment system thereof | |
| CN102506575B (en) | Treatment process for lignite upgrading waste water and lignite upgrading system | |
| CN214501259U (en) | Municipal sludge suspension drying and cleaning incineration equipment | |
| KR100933437B1 (en) | High water content of smokeless device | |
| JP4362428B2 (en) | Treatment method of sludge and incineration ash | |
| CN111623352A (en) | Self-sustaining incineration system and method for low-calorific-value high-ash sludge | |
| CN202808709U (en) | Sludge drying, pyrolysis gasifying and incinerating integrated treatment system | |
| KR100933438B1 (en) | High water content of carbonizing device | |
| CN111457388A (en) | System and method for co-burning solid hazardous waste and reducing dioxin discharge of chain furnace | |
| CN213699459U (en) | Sludge incineration heat exchange desulfurization and denitrification system | |
| CN216346273U (en) | System for innocent treatment mud | |
| CN213146581U (en) | Sludge drying and incineration resource utilization system | |
| CN216591718U (en) | Rubbish is drying system in advance based on thermal cracking cauldron | |
| CN205447766U (en) | Burner of carbomorphism mud |
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 | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |