CN108947200A - A kind of modified deep dehydration of sludge conditioning and desiccation charing process technique - Google Patents

Abstract

The invention discloses a sludge conditioning modification deep dehydration and drying carbonization treatment process, and relates to the technical field of sludge treatment and disposal. The present invention includes a sludge concentration system, a conditioning modification system, a filter press system, a crusher, a drying system, and a carbonization system; wherein, the conditioning modification system adopts a combination of inorganic and organic agents that do not contain chloride ions. Conditioning and modification; the filter press system can use a high-pressure steel plate and frame filter press or a diaphragm filter press, and adjust the pressing time and pressing pressure set in the deep dehydration mode. The present invention reduces the tail gas treatment cost and reduces the operating cost of the carbonization technology to a certain extent by adopting the method of combining inorganic and organic chemicals without chloride ions; The range control of the pressing time and pressing pressure of the machine has the advantages of saving resources, improving work efficiency, improving the economic benefits of the enterprise, and reducing costs.

Description

A sludge conditioning modified deep dehydration and dry carbonization treatment process

technical field

The invention belongs to the technical field of sludge treatment and disposal, and in particular relates to a sludge conditioning, modification, deep dehydration and drying carbonization treatment process.

Background technique

A large amount of sewage sludge is produced in our country every year, and the sludge contains a large number of toxic and harmful substances such as bacteria, fungi, parasites, pathogens and heavy metals. If these sludges are not treated in time and piled up arbitrarily, it will not only occupy a large amount of land resources but also easily cause secondary pollution to the environment.

At present, the mainstream sludge treatment and disposal technologies in the market include sludge landfill technology, aerobic composting technology, sludge anaerobic digestion technology, sludge incineration technology, sludge natural drying technology, sludge incineration technology, etc. Sludge landfill resources are limited and resources are seriously wasted; sludge aerobic composting technology has a long disposal cycle and limited reduction; sludge anaerobic digestion technology has large investment, high operating costs, safety issues, and produces a large amount of biogas residue, which needs to be recycled Treatment; the natural drying technology has a long cycle, occupies a large area, and is prone to odor during the drying process; the sludge incineration technology has a large investment, serious corrosion to the boiler, and high maintenance costs; it has a great impact on exhaust emissions and is prone to produce dioxins British and other harmful gases.

In the patent application number CN201511003635.8, a combined sludge deep dewatering system and deep dewatering process, the conditioner includes lime and polyalumina; the amount of lime added is 20-30% of the dry weight of the sludge %; the form of the polyaluminum chloride is powder or liquid, the addition of the powder polyaluminum chloride is 5-15% of the dry weight of the sludge, and the addition of the liquid polyaluminum chloride is 25-15% of the dry weight of the sludge 30%, while a kind of sludge conditioning and modification deep dehydration and dry carbonization treatment process of the present invention uses a combination of inorganic and organic chemicals without chloride ions for conditioning and modification, which can achieve sludge conditioning At the same time as the modification effect, it also has the component of reducing chloride ions in the soil, and avoids the pollution of the chloride ions in the treated soil to the soil and the harm to the plants.

In claim 9 of a sludge deep dehydration conditioning modification device and modification method thereof with the patent application number CN201710171278.9, the aluminum-iron salt described in step S3 is aluminum chloride, aluminum sulfate, and ferric chloride , ferrous sulfate, aluminum potassium sulfate, sodium aluminate, ferric sulfate, polyaluminum chloride, polyaluminum sulfate, polyferric chloride, polyferric sulfate at least one; and a kind of sludge conditioning modification of the present invention In the deep dehydration and dry carbonization treatment process, inorganic agents such as polysilicon aluminum, polysilicon ferrosilicon, polysilicon ferroaluminum, polyaluminum ferric aluminum sulfate can also be used, as well as polysilicon aluminum, polysilicon ferrosilicon, polysilicon ferrosilicon aluminum, polymer Aluminum ferric aluminum sulfate is mixed with at least one of polyaluminum sulfate, ferric sulfate and polyferric sulfate.

In the description of a large-scale centralized sludge treatment system with the patent application number CN201720880390.5, it is mentioned that the digestion and conditioning of sludge: In order to improve the performance of sludge removal water and improve the processing capacity of mechanical dehydration equipment, sludge Before concentration or dehydration, methods such as digestion or chemical conditioning are often used for pretreatment. The digestion of sludge is under artificial control, through the metabolism of microorganisms to stabilize the organic matter in the sludge. However, in the deep dehydration and dry carbonization treatment process of sludge conditioning and modification of the present invention, the combination of organic and inorganic agents is adopted, which has a variety of materials required for the process and improves the conditioning and modification of sludge. The role of the effect.

In view of the above problems, the present invention avoids the corrosion of equipment caused by the addition of conventional chemicals and the blockage of pipes caused by the formation of tar due to the reduction of the temperature of pyrolysis gas by adopting the combination of inorganic and organic chemicals that do not contain chloride ions, and improves the efficiency of pyrolysis gas. High utilization efficiency, reduced tail gas treatment cost, and reduced the operating cost of carbonization technology to a certain extent; through the secondary pressing of the high-pressure steel plate and frame filter press, and the range control of the pressing time and pressing pressure of the diaphragm filter press, Accurately achieve the desired deep dehydration effect, which has the advantages of saving electricity and fuel resources, improving work efficiency, improving the economic benefits of the enterprise, and reducing costs.

Contents of the invention

The purpose of the present invention is to provide a sludge conditioning modified deep dehydration and dry carbonization treatment process, through the combination of inorganic and organic agents without chloride ions and high-pressure steel plate and frame filter press, diaphragm press The operation of the filter machine solves the problems of soil pollution and harm to plants by chlorine ions in the existing disposed soil, waste of resources, soil pollution, and high cost of sludge treatment in enterprises.

In order to solve the problems of the technologies described above, the present invention is achieved through the following technical solutions:

The present invention is a sludge conditioning modified deep dehydration and dry carbonization treatment process, comprising the following steps: S1, the raw sludge with a moisture content of about 99% in the secondary settling tank of a sewage treatment plant is concentrated through a concentration system; S2, The concentrated sludge enters the conditioning system for conditioning and modification, or the sludge with a moisture content of about 80% is initially dehydrated by a belt filter press in a sewage treatment plant, and the sludge can directly enter the conditioning system and be diluted with water to a moisture content of about 95% before conditioning Modification; S3. After conditioning and modification, the sludge enters the filter press system for deep dehydration, and the water content of the mud cake is below 60%; S4. The mud cake after dehydration of the filter press system enters the crusher; S5. After crushing, the mud cake enters Drying system, the moisture content of the dried sludge is 20% to 30%; S6, put the crushed mud into the carbonization system for pyrolysis and carbonization: the crushed mud enters the inner cylinder of the carbonization furnace from the feed end of the carbonization furnace, and the carbonization product is discharged from the carbonization furnace The discharge end is discharged after cooling, and the carbonized product reaches a moisture content of less than 5%;

In the conditioning and modification system in S2, the conditioning and modification is carried out by combining inorganic and organic agents without chloride ions; the conditioning and modification system is applicable to sludge with a moisture content of 80% to 99.8%. The operation process of the conditioning modification system is as follows:

S201. Add inorganic chemicals to the concentrated sludge, and stir for 5-60 minutes;

S202, adding organic agents and stirring for 1-30 minutes.

Further, the thickening system in the step S1 can use a drum thickener, a gravity thickener, or a screw stack thickener to thicken the sludge.

Further, the inorganic agent is at least one of polysilicon aluminum, polysilicon ferrosilicon, polysilicon ferric aluminum, polyaluminum ferric aluminum sulfate, polyaluminum sulfate, ferric sulfate, and polyferric sulfate.

Further, the organic agent is polydimethyldiallylammonium chloride, dimethyldiallylammonium chloride, acrylamide copolymer, polyallylamine hydrochloride, dodecylbenzene Sodium Sulfonate, Sodium Linear Alkylbenzene Sulfonate, TX-10 Emulsifier, Chitosan Hydrochloride, Chitosan Quaternary Ammonium Salt, Chitosan Lactate, Chitosan Glutamate, Polyethylene At least one of alcohol, polyetheramine and polyacrylamide.

Further, the dosage ratio of the inorganic chemical agent is 1%-80% of the dry weight of the sludge, and the dosage ratio of the organic chemical agent is 0-1% of the dry weight of the sludge.

Further, the filter press system in the step S3 can adopt a high-pressure steel plate and frame filter press; the model of the high-pressure steel plate and frame filter press is a high-pressure steel plate and frame filter press MF-120; the The sludge treatment capacity of the high-pressure plate-and-frame filter press is 20 to 40 cubic meters. The operation process of the high-pressure steel plate-and-frame filter press for deep dehydration is as follows:

S301. Feed the high-pressure steel plate and frame filter press for one time, the time for the one time feeding is 20-30 minutes, and the pressure for the one-time feeding is 0.6-1 MPa;

S302. After one feeding is completed, start a pressing, the time of the first pressing is 5-20 minutes, and the maximum pressing pressure of the first pressing is 2.5-5 MPa;

S303. After the primary pressing is completed, start the secondary feeding, the time of the secondary feeding is 5-15 minutes, and the pressure of the secondary feeding is 0.6-1 MPa;

S304. After the secondary feeding is completed, start the secondary pressing, the secondary pressing time is 10-25min, and the maximum pressing pressure of the secondary pressing is 2.5-5MPa; that is, the moisture content of the mud cake after dehydration is 60 %the following.

Further, the filter press system in the step S3 can adopt a diaphragm filter press; the model of the diaphragm filter press is a diaphragm filter press XMZGS300/1500-UF; the filtration area of the diaphragm filter press is 100 to 450 square meters m, the sludge treatment capacity is 20-400 cubic meters; the deep dehydration mode of the membrane filter press includes low-pressure mud feeding and high-pressure mud feeding; the pressing time of the membrane filter press is 40-70min, and the pressing pressure is 1.1- 2.0MPa; that is, the moisture content of the mud cake after dehydration is below 60%.

Further, when the low-pressure mud is fed, the operation of the diaphragm filter press is set as follows: the low-pressure mud-feeding time is set to 60-120 minutes, and the low-pressure mud-feeding pressure is set to 0.5-0.7 MPa; when the high-pressure mud is fed, the diaphragm pressure The operation setting of the filter machine is: the high-pressure mud feeding time is set to 40-60 minutes, and the high-pressure mud feeding pressure is set to 0.9-1.2MPa.

Further, the drying system in step S5 includes a drying biomass burner, a drying auxiliary combustion chamber, and an internal heating drying furnace; the drying biomass burner ignites biomass fuel, and the heat generated is passed through the drying The auxiliary combustion chamber enters the internal heating drying furnace and directly contacts the sludge to provide heat; it can improve the effective utilization rate of heat.

Further, the carbonization system in step S6 includes a carbonization biomass burner, a second combustion chamber, and an externally heated carbonization furnace; the externally heated carbonization furnace includes a cylinder; the two ends of the cylinder are respectively provided with material seals ; The cylinder includes an inner cylinder and an outer cylinder, and a thermal insulation jacket layer is provided between the inner cylinder and the outer cylinder; the inner surface of the inner cylinder is provided with a diversion mechanism, and the sludge under the action of the inner cylinder diversion mechanism Move from the feed end to the discharge end.

Further, the carbonization biomass burner in the carbonization system ignites the biomass fuel, and the hot gas generated enters the jacket layer from the hot gas inlet near the sludge discharge end after passing through the second combustion chamber, and directly affects the sludge in the carbonization furnace cylinder. Heating, from the hot gas outlet close to the sludge feed end, it is drawn into the drying furnace through a high-temperature fan; the pyrolysis gas generated by the carbonization of the sludge in the inner cylinder of the carbonization furnace enters the ignition end of the secondary combustion chamber through the heat preservation and heating pipe for direct combustion; The waste heat of the carbonization furnace is effectively used to heat the drying furnace, and the tail gas is discharged after treatment, which has the advantages of saving resources, reducing energy consumption, and reducing gas pollution.

Further, the drying system generally uses the waste heat of the carbonization furnace for heat supply. In special cases, such as: when the carbonization waste heat cannot meet the heating temperature of the drying furnace, the drying auxiliary combustion chamber is used for heat supply; The required temperature is 150-220°C, the drying time is 30-40min, and the moisture content of the sludge after drying is 20%-30%. The moisture content of the product is below 5%.

The present invention has the following beneficial effects:

1. The present invention avoids the corrosion of equipment caused by the addition of conventional chemicals and the blockage of pipes caused by the formation of tar due to the reduction of the temperature of pyrolysis gas by adopting the combination of inorganic and organic chemicals that do not contain chloride ions, and improves the utilization of pyrolysis gas Efficiency, reducing the cost of tail gas treatment, and reducing the operating cost of carbonization technology to a certain extent.

2. The present invention precisely achieves the required deep dehydration effect through the secondary pressing of the high-pressure steel plate and frame filter press, as well as the pressing time and pressing pressure range of the diaphragm filter press, and saves power and fuel resources. , Improve work efficiency, improve the economic benefits of enterprises, and reduce costs.

3. The present invention has the advantages of more thorough reduction and stabilization: the final moisture content of the carbonized product is below 5%, the reduction rate is large, and the carbonized product has undergone a qualitative change, and the carbonized product will no longer turn into sludge when it meets water, forming a Stabilization; it has the advantages of a wide range of applications: the sludge objects that can be treated are diversified, and it is more effective for sludge of different properties, including municipal sludge, industrial sludge, petroleum sludge, stock sludge and sludge with different moisture content. Good applicability and strong practicability; it has the advantage of being harmless: after high temperature treatment, harmful pathogens in the sludge are killed, and heavy metals are chelated and fixed to form a stable state; it has the advantage of resource utilization: the carbonization The product can be used as low-value fuel, activated carbon, soil improver, snow melting agent, nutrient soil raw material, etc. for resource utilization; it has the advantages of improving the utilization efficiency of pyrolysis gas, while reducing the amount of flue gas and reducing the cost of tail gas treatment.

Of course, any product implementing the present invention does not necessarily need to achieve all the above-mentioned advantages at the same time.

Description of drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the accompanying drawings that are required for the description of the embodiments. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. Those of ordinary skill in the art can also obtain other drawings based on these drawings without any creative effort.

Fig. 1 is a process flow chart of the present invention for conditioning, modifying, deep dehydration and carbonization of sludge.

Detailed ways

The technical solutions in the embodiments of the present invention are clearly and completely described. Obviously, the described embodiments are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

Specific embodiment 1

Please refer to Fig. 1, the present invention is a sludge conditioning modified deep dehydration and dry carbonization treatment process, including the following steps:

S1. The municipal mud with a water content of about 99% in the secondary sedimentation tank of the sewage treatment plant is concentrated through the concentration system;

S2. After concentrating the sludge, carry out preliminary dehydration, and then enter the municipal mud with a moisture content of 80% into the conditioning system: first dilute it with water to a moisture content of 95%, then perform conditioning modification, then add polysilicon aluminum 35%, and stir for 30 minutes; Add 0.2% polyacrylamide and stir for 5 minutes;

S3. After conditioning and modification, the sludge enters the high-pressure steel plate and frame filter press: the treated sludge can be mechanically dehydrated with a special high-pressure plate and frame filter press. Among them, the filter plate of the filter press has an area of 120 square meters. The sludge treatment capacity is about 20 cubic meters, and the press filter is secondary feeding and secondary pressing: once feeding 30min, feeding pressure 1MPa, once pressing time 15min, maximum pressing pressure 2.8MPa; secondary feeding 10min, feeding pressure 1MPa, secondary pressing time 25min, maximum pressing pressure 2.8MPa, moisture content of mud cake after dehydration is 57%;

S4. After the dehydrated mud cake is crushed by a crusher, it enters the drying furnace. The temperature of the drying furnace is 200° C., the drying time is 30 minutes, and the moisture content of the dried sludge is 20%;

S5. The dried crushed mud enters the inner cylinder of the carbonization furnace, the temperature of the carbonization furnace is 500°C, the carbonization time is 30min, and the moisture content of the carbonization product is 2%;

S6. Enter the crushed mud into the carbonization system for pyrolysis and carbonization: the crushed mud enters the inner cylinder of the carbonization furnace from the feed end of the carbonization furnace, and the carbonization product is discharged from the discharge end of the carbonization furnace after being cooled.

Specific embodiment 2

Please refer to Fig. 1, the present invention is a sludge conditioning modified deep dehydration and dry carbonization treatment process, including the following steps:

S1. Put 98.5% of industrial sludge directly into the conditioning system for conditioning and modification: first add 60% of polysilicon, and stir for 20 minutes; then add 0.3% of polyetheramine, and stir for 5 minutes;

S2. After conditioning and modification, the sludge enters the membrane filter press: the treated sludge can be mechanically dehydrated with the membrane filter press; the filter area of the filter press is 250 square meters, and the sludge treatment capacity is about 120 cubic meters. Filtration includes low-pressure mud feeding and high-pressure mud feeding: Among them, low-pressure mud feeding is 90 minutes, mud feeding pressure is 0.5 MPa; high-pressure mud feeding is 50 minutes, mud feeding pressure is 1 MPa; pressing time is 60 minutes, pressing pressure is 1.6 MPa; the moisture content of mud cake after dehydration is 59 %;

S3. After dehydration, the mud cake is crushed by a crusher, and then enters the drying furnace. The temperature of the drying furnace is 180°C, the drying time is 40 minutes, and the moisture content of the dried sludge is 25%;

S4. The dried crushed mud enters the inner cylinder of the carbonization furnace, the temperature of the carbonization furnace is 480°C, the carbonization time is 30min, and the moisture content of the carbonization product is 3%;

S5. Enter the crushed mud into the carbonization system for pyrolysis and carbonization: the crushed mud enters the inner cylinder of the carbonization furnace from the feed end of the carbonization furnace, and the carbonization product is discharged from the discharge end of the carbonization furnace after being cooled.

In the description of this specification, descriptions with reference to the terms "one embodiment", "example", "specific example" and the like mean that specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment of the present invention. In an embodiment or example. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The preferred embodiments of the invention disclosed above are only to help illustrate the invention. The preferred embodiments are not exhaustive in all detail, nor are the inventions limited to specific embodiments described. Obviously, many modifications and variations can be made based on the contents of this specification. This description selects and specifically describes these embodiments in order to better explain the principle and practical application of the present invention, so that those skilled in the art can well understand and utilize the present invention. The invention is to be limited only by the claims, along with their full scope and equivalents.

Claims (10)

1. A sludge conditioning and modification deep dehydration and dry carbonization treatment process, including the following steps: S1, the raw sludge is concentrated through the concentration system; S2, and then enters the conditioning modification system for conditioning modification; S3 , and then enter the filter press system for deep dehydration; S4, the mud cake dehydrated by the filter press system enters the crusher; S5, the crushed mud cake enters the drying system for drying treatment; S6, and then carbonizes through the carbonization system treatment; it is characterized in that: in the conditioning and modification system in S2, the method of combining inorganic and organic agents without chloride ions is used for conditioning and modification; the operation process of the conditioning and modification system is: S201. Add inorganic chemicals to the concentrated sludge, and stir for 5-60 minutes; S202, adding organic agents and stirring for 1-30 minutes. 2. A kind of sludge conditioning modified deep dehydration and dry carbonization treatment process according to claim 1, characterized in that the inorganic agent is polysilicon aluminum, polysilicon ferrosilicon, polysilicon ferrosilicon, polyaluminum iron At least one of aluminum sulfate, polyaluminum sulfate, ferric sulfate, and polyferric sulfate. 3. A kind of sludge conditioning modified deep dehydration and dry carbonization treatment process according to claim 1, characterized in that, the organic agent is polydimethyldiallylammonium chloride, dimethyldiallylammonium Allyl ammonium chloride, acrylamide copolymer, polyallylamine hydrochloride, sodium dodecylbenzene sulfonate, sodium linear alkylbenzene sulfonate, TX-10 emulsifier, chitosan hydrochloride Salt, chitosan quaternary ammonium salt, chitosan lactate, chitosan glutamate, polyvinyl alcohol, polyetheramine, polyacrylamide at least one. 4. A kind of sludge conditioning modification deep dehydration and dry carbonization treatment process according to claim 1, characterized in that, the dosage ratio of the inorganic agent is 1% to 80% of the dry weight of the sludge, and the organic agent The dosing ratio is 0-1% of the dry weight of the sludge. 5. A kind of sludge conditioning modified depth dehydration and dry carbonization treatment process according to claim 1, characterized in that, the press filter system in the step S3 can adopt a high-pressure steel plate and frame filter press; The operation process of high-pressure steel plate and frame filter press for deep dehydration is as follows: S301. Feed the high-pressure steel plate and frame filter press for one time, the time for the one time feeding is 20-30 minutes, and the pressure for the one-time feeding is 0.6-1 MPa; S302. After one feeding is completed, start a pressing, the time of the first pressing is 5-20 minutes, and the maximum pressing pressure of the first pressing is 2.5-5 MPa; S303. After the primary pressing is completed, start the secondary feeding, the time of the secondary feeding is 5-15 minutes, and the pressure of the secondary feeding is 0.6-1 MPa; S304. After the secondary feeding is completed, start the secondary pressing, the time of the secondary pressing is 10-25 minutes, and the maximum pressing pressure of the secondary pressing is 2.5-5 MPa. 6. A kind of sludge conditioning modified deep dehydration and dry carbonization treatment process according to claim 1, characterized in that, the filter press system in the step S3 can adopt a membrane filter press; the membrane filter press The deep dehydration mode of the machine includes low-pressure mud feeding and high-pressure mud feeding; the pressing time of the diaphragm filter press is 40-70 minutes, and the pressing pressure is 1.1-2.0 MPa; When the low-pressure mud is fed, the operation of the diaphragm filter press is set to: the low-pressure mud-feed time is set to 60-120min, and the low-pressure mud-feed pressure is set to 0.5-0.7MPa; when the high-pressure mud is fed, the diaphragm filter press The operation settings are as follows: the high-pressure mud feeding time is set to 40-60 minutes, and the high-pressure mud feeding pressure is set to 0.9-1.2 MPa. 7. A kind of sludge conditioning modification deep dehydration and drying carbonization treatment process according to claim 1, characterized in that, the drying system in the step S5 includes a drying biomass burner, a drying auxiliary combustion chamber and an internal heating type drying furnace; the drying biomass burner ignites biomass fuel, and the hot gas generated enters the internal heating type drying furnace through the drying auxiliary combustion chamber and directly contacts the sludge for heat supply; the effective utilization rate of heat can be improved. 8. A kind of sludge conditioning modification deep dehydration and dry carbonization treatment process according to claim 1, characterized in that, the carbonization system in the step S6 includes a carbonization biomass burner, a secondary combustion chamber and an external heat type carbonization furnace; the external heating type carbonization furnace includes a cylinder; the two ends of the cylinder are respectively provided with material seals; the cylinder includes an inner cylinder and an outer cylinder, and an insulation Jacket layer; the inner surface of the inner cylinder is provided with a flow guide mechanism, and the sludge moves from the feed end to the discharge end under the action of the flow guide mechanism of the inner cylinder. 9. A kind of sludge conditioning modified deep dehydration and dry carbonization treatment process according to claim 1, characterized in that, the pyrolysis gas produced by the carbonization of the sludge in the carbonization furnace inner cylinder in the carbonization system is passed through the thermal insulation The heat tracing pipe enters the ignition end of the secondary combustion chamber for direct combustion. 10. A kind of sludge conditioning modified deep dehydration and dry carbonization treatment process according to claim 1, characterized in that, the carbonization biomass burner in the carbonization system ignites the biomass fuel, and the generated hot gas passes through the secondary combustion After entering the thermal insulation jacket layer from the hot air inlet near the sludge discharge end, the sludge in the carbonization furnace cylinder is indirectly heated, and is drawn into the drying furnace from the hot air outlet near the sludge feed end through a high-temperature fan ; The waste heat of the carbonization furnace is used to supply heat to the drying furnace, and the tail gas is discharged after being processed.