CN219526428U - Pretreatment system for kitchen biogas slurry - Google Patents

Abstract

The utility model relates to a pretreatment system for kitchen biogas slurry, which comprises a first dosing tank, a spiral-pile filter press, an oil separation tank, a second dosing tank, an air floatation tank and a clear water tank, wherein a feed inlet of the spiral-pile filter press is connected with a feed outlet of the first dosing tank, the feed outlet of the spiral-pile filter press is connected with a feed inlet at the bottom of the oil separation tank, a partition plate and an oil absorption assembly are arranged in the oil separation tank, the partition plate is vertically connected to the bottom of the oil separation tank, the oil absorption assembly is transversely connected with a notch of the oil separation tank, the height of the oil absorption assembly is higher than the top of the partition plate, and sewage entering the oil separation tank overflows from one side of the partition plate to the other side of the partition plate; the air floatation tank is connected with an air dissolving device, and a slag scraping machine is arranged at the notch of the air floatation tank; the first dosing tank and the second dosing tank are internally provided with stirrers. The pretreatment system for the kitchen biogas slurry can effectively realize extraction of grease and efficient degradation of pollutant concentration, has small occupied area and self-flowing inside, and saves energy consumption and cost.

Description

Pretreatment system for kitchen biogas slurry

Technical Field

The utility model relates to the technical field of sewage treatment, in particular to a pretreatment system for kitchen biogas slurry.

Background

The project inspection of a plurality of garbage-loading and garbage-burning power plants shows that part of sewage treatment stations receive the effluent of kitchen biogas slurry CSTR (continuous stirred tank reactor, continuous stirring reactor system), the sewage is usually pretreated by a plurality of working procedures to realize oil extraction and pollutant degradation, the working procedures are dispersed, a plurality of power lifting procedures are needed, an operation platform is needed to be arranged to realize gravity flow, the occupied area is large, the construction is restricted, and additional cost is needed to add a water pump.

Disclosure of Invention

Therefore, a pretreatment system for kitchen biogas slurry is needed to solve the problem of large occupied area of the existing pretreatment system.

In order to achieve the aim, the inventor provides a pretreatment system for kitchen biogas slurry, which comprises a first dosing tank, a spiral shell stacking filter press, an oil separation tank, a second dosing tank, an air floatation tank and a clear water tank which are sequentially arranged along the water flow direction,

the first dosing tank is externally connected with sewage, the feed inlet of the spiral filter press is connected with the discharge outlet of the first dosing tank, the discharge outlet of the spiral filter press is connected with the feed inlet at the bottom of the oil separating tank, a partition plate and an oil absorption assembly are arranged in the oil separating tank, the partition plate is vertically connected to the bottom of the oil separating tank, the oil absorption assembly is transversely connected to the notch of the oil separating tank, the height of the oil absorption assembly is higher than the top of the partition plate, and sewage entering the oil separating tank overflows from one side of the partition plate to the other side of the partition plate;

the air floatation tank is connected with an air dissolving device, and a slag scraping machine is arranged at the notch of the air floatation tank;

the first dosing tank and the second dosing tank are internally provided with stirrers.

Further, the oil absorption assembly comprises a winding rod and oil absorption cotton wound on a roll shaft, and an oil absorption cotton mounting opening is formed in one side of the roll shaft.

Further, the pretreatment system further comprises a pressure filter tank, and the first dosing tank and the spiral shell stacking filter press are arranged in the pressure filter tank.

Further, the bottoms of the pressure filter tank, the oil separation tank and the air floatation tank are all provided with a sludge collecting tank.

Further, the slag scraping machine is connected with a slag discharging pipe, and a discharge hole of the slag discharging pipe is connected into a sludge collecting tank at the bottom of the air floatation tank.

Further, the pretreatment system further comprises a gas collecting hood, wherein the gas collecting hood is arranged above the pressure filtering tank, the oil isolating tank, the air floating tank and the clear water tank, and the gas collecting hood is externally connected with an odor treatment system.

Further, the baffle is arranged close to the feed inlet at the bottom of the oil separating groove.

Further, the first dosing tank comprises two dosing grids, the two dosing grids are respectively used for adding PAC and PAM, and stirrers are arranged in the two dosing grids;

the structure of the second dosing tank is the same as that of the first dosing tank.

Further, the pretreatment system further comprises an overrun pipe, one end of the overrun pipe is externally connected with sewage, and the other end of the overrun pipe is communicated with the oil separation groove.

Further, the pretreatment system further comprises a water outlet pump, wherein the water outlet pump is arranged in the clean water tank, and the water outlet pump is externally connected with the biochemical tank.

Compared with the prior art, the technical scheme has the following advantages: the pretreatment system for the kitchen biogas slurry is suitable for pretreatment of CSTR effluent of the kitchen biogas slurry or as pretreatment equipment of a high-concentration high-oil sewage treatment station, and can effectively ensure stable operation of a subsequent biochemical system. The high-efficiency pretreatment equipment integrates the spiral filter press, the oil separation tank, the air floatation tank and the clear water tank, can effectively realize extraction of grease and high-efficiency degradation of pollutant concentration, has small occupied area, automatically flows inside, and saves energy consumption and cost.

Drawings

FIG. 1 is a side view of an oil separator tank of a pretreatment system for kitchen slurry according to the present embodiment;

FIG. 2 is a top view of an oil separator tank of a pretreatment system for kitchen biogas slurry according to the present embodiment;

FIG. 3 is a side view of a pretreatment system for kitchen slurry according to the present embodiment;

fig. 4 is a top view of a pretreatment system for kitchen biogas slurry according to the present embodiment.

Reference numerals illustrate:

1. a pressure filtration tank;

11. a first dosing tank;

12. a spiral filter press;

2. an oil separator;

21. a partition plate;

22. an oil absorbing assembly;

221. an oil absorption cotton mounting port;

23. a separation region;

24. a precipitation zone;

3. a second dosing tank;

4. an air floatation tank;

41. a gas dissolving device;

42. a slag scraping machine;

421. a slag discharge pipe;

5. a clean water tank;

51. a liquid level gauge;

6. a stirrer;

7. a sludge collection tank;

8. a gas collecting hood;

91. mud valve

92. Blow-off valve

93. Overrunning pipe

94. Water outlet pump

Detailed Description

In order to describe the possible application scenarios, technical principles, practical embodiments, and the like of the present utility model in detail, the following description is made with reference to the specific embodiments and the accompanying drawings. The embodiments described herein are only for more clearly illustrating the technical aspects of the present utility model, and thus are only exemplary and not intended to limit the scope of the present utility model.

Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the utility model. The appearances of the phrase "in various places in the specification are not necessarily all referring to the same embodiment, nor are they particularly limited to independence or relevance from other embodiments. In principle, in the present utility model, as long as there is no technical contradiction or conflict, the technical features mentioned in each embodiment may be combined in any manner to form a corresponding implementable technical solution.

Unless defined otherwise, technical terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present utility model pertains; the use of related terms herein is for the purpose of describing particular embodiments only and is not intended to limit the utility model.

In the description of the present utility model, the term "and/or" is a representation for describing a logical relationship between objects, which means that three relationships may exist, for example a and/or B, representing: there are three cases, a, B, and both a and B. In addition, the character "/" herein generally indicates that the front-to-back associated object is an "or" logical relationship.

In the present utility model, terms such as "first" and "second" are used merely to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual number, order, or sequence of such entities or operations.

Without further limitation, the use of the terms "comprising," "including," "having," or other like terms in this specification is intended to cover a non-exclusive inclusion, such that a process, method, or article of manufacture that comprises a list of elements does not include additional elements but may include other elements not expressly listed or inherent to such process, method, or article of manufacture.

As in the understanding of "review guidelines," the expressions "greater than", "less than", "exceeding" and the like are understood to exclude this number in the present utility model; the expressions "above", "below", "within" and the like are understood to include this number. Furthermore, in the description of embodiments of the present utility model, the meaning of "a plurality of" is two or more (including two), and similarly, the expression "a plurality of" is also to be understood as such, for example, "a plurality of" and the like, unless specifically defined otherwise.

In the description of embodiments of the present utility model, spatially relative terms such as "center," "longitudinal," "transverse," "length," "width," "thickness," "up," "down," "front," "back," "left," "right," "vertical," "horizontal," "vertical," "top," "bottom," "inner," "outer," "clockwise," "counter-clockwise," "axial," "radial," "circumferential," etc., are used herein as a basis for the description of the embodiments or as a basis for the description of the embodiments, and are not intended to indicate or imply that the devices or components referred to must have a particular position, a particular orientation, or be configured or operated in a particular orientation and therefore should not be construed as limiting the embodiments of the present utility model.

Unless specifically stated or limited otherwise, the terms "mounted," "connected," "affixed," "disposed," and the like as used in the description of embodiments of the utility model should be construed broadly. For example, the "connection" may be a fixed connection, a detachable connection, or an integral arrangement; the device can be mechanically connected, electrically connected and communicated; it can be directly connected or indirectly connected through an intermediate medium; which may be a communication between two elements or an interaction between two elements. The specific meaning of the above terms in the embodiments of the present utility model can be understood by those skilled in the art to which the present utility model pertains according to circumstances.

Referring to fig. 1 to 4, the pretreatment system for kitchen biogas slurry of the present embodiment includes a first dosing tank 11, a spiral shell stacking filter press 12, an oil separation tank 2, a second dosing tank 3, an air floatation tank 4 and a clean water tank 5 sequentially arranged along the water flow direction,

the first dosing tank is externally connected with sewage, the feed inlet of the spiral filter press is connected with the discharge outlet of the first dosing tank, the discharge outlet of the spiral filter press is connected with the feed inlet at the bottom of the oil separating tank, a partition plate 21 and an oil absorption assembly 22 are arranged in the oil separating tank, the partition plate is vertically connected with the bottom of the oil separating tank, the oil absorption assembly is transversely connected with the notch of the oil separating tank, the height of the oil absorption assembly is higher than the top of the partition plate, and sewage entering the oil separating tank overflows from one side of the partition plate to the other side of the partition plate;

the air floatation tank is connected with an air dissolving device 41, and a slag scraping machine 42 is arranged at the notch of the air floatation tank;

the first dosing tank and the second dosing tank are internally provided with a stirrer 6.

PAC and PAM are sequentially added in the first dosing tank, suspended matters in sewage and the PAC and PAM undergo flocculation reaction to form flocs, and the effect of filter pressing is promoted. PAC and PAM are sequentially added into the second dosing tank, suspended matters in water react with PAC and PAM in a flocculation reaction to form flocs, and the air floatation promotion effect is achieved. The stirrer arranged in the first dosing tank and the second dosing tank can be used for fully mixing the added medicament and biogas slurry.

The spiral shell filter press can filter and press the kitchen biogas slurry, and separate sludge in the kitchen biogas slurry. Usually, the effluent SS (suspended solids) of the kitchen biogas slurry CSTR (continuous stirred tank reactor, continuous stirred reactor system) is up to 60000 or more, and if such high concentration sewage enters the oil separation tank and the air floatation tank, the oil separation tank cannot operate normally. The front end is provided with the spiral shell pressure filter, SS (suspended solids) can be effectively removed, filtrate after pressure filtration is conveyed to the oil separation tank through the filtrate pipe, and most of SS (suspended solids) are removed together with sludge, so that the load of the oil separation tank and the air flotation tank is reduced. The subsequent oil-gas separation floating effect is ensured.

The baffle in the oil separating groove can change the sewage flow direction, and the baffle separates the oil separating groove into two regions, is separation district and sedimentation zone respectively, and sewage overflows to the sedimentation zone from bottom to top after getting into the separation district of oil separating groove, and sewage is under sedimentation zone gravity effect, and grease come-up is absorbed by the oil absorption subassembly to the surface of water top, great pollutant deposit in bottom mud collecting vat.

Set up a baffle in the oil separating groove, filter-pressing groove play water is collected the feed inlet to the oil separating groove bottom by the filtrate collecting pipe, utilizes the baffle to change water flow direction, and rivers are by supreme flowing automatically to the oil separating groove sedimentation zone down in the effect of baffle, avoid secondary power to promote. In certain preferred embodiments, the baffle is disposed adjacent to the feed inlet at the bottom of the oil sump.

The air dissolving device can generate a large number of micro bubbles, the aggregated suspended matters adhere to the bubbles and float on the top of the air floatation tank, and larger particulate matters sink to the bottom of the air floatation tank.

The clear water tank stores the air-floating water, has certain buffering time and ensures that the clear water outlet pump has certain installation space.

In some preferred embodiments, the oil absorbing assembly includes a winding rod and oil absorbing cotton wound on a roller shaft, and one side of the roller shaft is provided with an oil absorbing cotton mounting hole 221. Opening the cover plate of the oil absorbing cotton mounting port, rolling the oil absorbing cotton into a cylinder shape, sleeving the oil absorbing cotton spreading winding rod, and rotating the winding rod to spread the oil absorbing cotton above the oil isolating groove to absorb floating oil. After absorbing for a period of time, the oil absorbing cotton can be also rolled to be cylindrical by utilizing the rolling rod, and the new oil absorbing cotton can be taken out from the oil absorbing cotton mounting port to replace, so that the operation is convenient. The oil absorbing cotton is made of lipophilic superfine fiber nonwoven fabric, does not contain chemical agents, does not cause secondary pollution, can rapidly absorb oil stains, organic solvents, hydrocarbon, vegetable oil and other liquids with the weight of tens of times, and does not generate toxic and harmful gases after combustion. The oil-absorbing cotton can be dried after oil is collected, and is collected into a bag to be used as fuel to be purchased to a garbage incineration plant and the like, so that the resource recovery is realized.

In certain preferred embodiments, the pretreatment system further comprises a pressure filter tank 1, wherein the first dosing tank and the spiral stack filter press are both disposed within the pressure filter tank. In some more preferred embodiments, the bottom of the pressure filter tank, the oil separator tank and the air floatation tank are provided with a sludge collecting tank 7. The waste residue of the spiral shell filter press can be directly discharged into a sludge collecting tank of the pressure filter tank. In some preferred embodiments, the slag scraping machine is connected with a slag discharging pipe, and a discharge hole of the slag discharging pipe is connected into a sludge collecting tank at the bottom of the air floatation tank. The scum above the air floatation tank is collected to a slag discharge pipe 421 through a slag scraping machine, and is discharged to a sludge collecting tank below the air floatation tank through the slag discharge pipe under the action of gravity to be treated together with sludge. Because the front end is provided with the spiral shell pressure filter and the oil separation groove, less grease is in the scum scraped by the scum scraping machine, and the scum can be treated together with sludge, so that the process of collecting and treating the scum in addition is reduced.

In certain preferred embodiments, the pretreatment system further comprises a gas-collecting hood 8, wherein the gas-collecting hood is arranged above the pressure filtering tank, the oil separation tank, the air floatation tank and the clear water tank, and is externally connected with an odor treatment system. The kitchen biogas slurry has odor, the odor is collected above the whole pretreatment system by arranging the gas collecting hood for wrapping, and the odor is conveyed to the odor treatment system, so that the surrounding environment is effectively improved. The gas collecting hood can be made of glass fiber reinforced plastic materials, can be assembled on site according to space height, and is convenient to install and low in price.

In some preferred embodiments, the first dosing tank comprises two dosing grids, wherein the two dosing grids are respectively used for adding PAC and PAM, and a slurry stirrer is arranged in each dosing grid;

the structure of the second dosing tank is the same as that of the first dosing tank.

The biogas slurry firstly enters a PAC dosing stirring tank, the residence time is about 1-3min, the sewage and PAC are fully mixed, and the biogas slurry automatically flows into another PAM dosing stirring tank, and the residence time is about 10min.

In certain preferred embodiments, the pretreatment system further comprises an overrun pipe 93, one end of which is externally connected with sewage, and the other end of which is communicated with the oil separator. When the pretreatment system is not high in water inlet SS (suspended matters) or the filter pressing tank equipment fails, the inlet water can overrun the filter pressing tank to the oil separation tank through the overrun pipe.

In certain preferred embodiments, the pretreatment system further comprises a water outlet pump 94 disposed within the clean water tank, the water outlet pump circumscribing the biochemical basin. The defect that the traditional pretreatment system can only automatically flow to a biochemical pond by arranging the pretreatment system at a high position is avoided.

In certain preferred embodiments, a cat ladder is provided outside the pretreatment system, and access to the top of the system is possible through the cat ladder.

The inventors also provided the following specific examples:

a pretreatment system for kitchen biogas slurry is used for pretreatment of water discharged from a CSTR (continuous stirred tank reactor, continuous stirring reactor system) of the kitchen biogas slurry or as a pretreatment system of a high-concentration high-oil sewage treatment station, so that stable operation of a subsequent biochemical system is effectively ensured. And the front-end biogas slurry CSTR (continuous stirred tank reactor, continuous stirring reactor system) is discharged and sequentially enters a first dosing tank, a pressure filtering tank, an oil separating tank, a second dosing tank, an air floatation tank and a clear water tank. PAC and PAM are externally added, most of grease is extracted under the actions of a spiral-shell filter press, a partition plate, an oil absorption assembly and a gas dissolving device, and organic matters such as SS (suspended substances), COD (chemical oxygen demand) and the like are removed, wherein the amount of the reducing substances to be oxidized in the water sample is measured by a chemical method. The scum and the sludge are collected in a sludge collecting tank under the action of gravity and a slag scraping machine and a slag discharging pipe. The clear water treated by the pretreatment system automatically flows to the clear water tank and can be conveyed to a subsequent biochemical treatment tank through a built-in water outlet pump. The pretreatment system is provided with a gas collecting hood outside, wraps the upper part of the whole system and is conveyed to the odor treatment system through an odor pipe. The pretreatment system outside sets up the cat ladder, can overhaul through cat ladder to equipment top.

A pretreatment systems for kitchen natural pond liquid is equipped with first dosing tank, disposes first dosing tank volume according to the flow size of front end natural pond liquid lift pump that intakes, and first dosing tank divides two check, sets up the thick liquid agitator respectively. The biogas slurry firstly enters a PAC dosing stirring tank, the residence time is about 1-3min, the sewage and PAC are fully mixed, and the biogas slurry flows from another PAM dosing stirring tank for about 10min. The suspended matters in the sewage and PAC and PAM are subjected to flocculation reaction to form flocs, so that the effect of filter pressing is promoted.

A pretreatment system for kitchen biogas slurry is provided with a filter pressing groove, a spiral shell stacking filter press is arranged in the filter pressing groove, and the treatment specification of the spiral shell stacking filter press is configured according to the flow of a front-end biogas slurry inlet lifting pump. The effluent of the first dosing tank automatically flows to the spiral shell stacking machine, most suspended matters in water are filtered through spiral shell stacking, and the operation load of the subsequent oil-gas separation floating tank is reduced. The filtrate of the spiral shell stacking machine flows to the water inlet of the oil separation tank through the filtrate collecting pipe, and the sludge outlet of the spiral shell stacking machine automatically flows to the sludge collecting tank.

Baffle in the oil separation district establishes at the oil separation groove water inlet end, 300mm horizontal distance apart from the feed inlet of oil separation groove bottom, baffle top 500mm distance apart from the oil separation groove top. The feed inlet at the bottom of the oil separation tank changes the flow direction of water flow to the bottom to the top through the partition plate, and enters the precipitation area of the oil separation tank.

In the oil separation sedimentation zone, under the action of gravity, the grease with the density smaller than water floats to the upper part of the oil separation tank, the suspended matters with the density larger than water are sedimented in the sludge collecting tank, and the sewage automatically flows to the second dosing tank.

The efficient oil absorption device consists of oil absorption cotton, an oil absorption cotton spreading winding rod and an oil absorption cotton mounting port. Is arranged at a position 300mm away from the top of the oil separation groove.

A pretreatment systems for kitchen natural pond liquid is equipped with the second and adds the medicine groove, and according to the flow size configuration second that front end natural pond liquid advances water lift pump adds the medicine groove volume, the second adds the medicine groove and divides two check, sets up the thick liquid agitator respectively. The biogas slurry firstly enters a PAC dosing stirring tank, the retention time is about 1-3min, the sewage and PAC are fully mixed, and the biogas slurry flows from another PAM dosing stirring tank for about 10mmin. Suspended matters in the sewage react with PAC and PAM in a flocculation reaction to form flocs, and the effect of promoting air floatation is achieved.

The pretreatment system for the kitchen biogas slurry is provided with an air floatation tank, and an oil scraping machine, a slag discharging pipe, a gas dissolving device and a slag discharging pipe are arranged in the air floatation tank. And water discharged from the second dosing tank flows into the air floatation tank.

The air dissolving device can enable a large number of micro bubbles to be generated in the air flotation tank water, suspended matters in sewage react with PAC (programmable logic controller) and PAM (polyacrylamide) to form floccules to adhere to the bubbles and float on the top of the air flotation tank.

The slag scraping machine is arranged on the top of the air floatation tank, and scum floating above the air floatation tank is collected in the slag discharging pipe through the slag scraping machine.

And the slag discharging pipe is used for collecting scum in the air flotation tank, and the scum flows to the sludge collecting tank under the action of gravity in the slag discharging pipe.

The water discharged from the air flotation tank automatically flows to a clear water tank, the clear water tank determines the volume according to the inflow of biogas slurry at the front end, the hydraulic retention time is 0.5-1h, and the water level surface is designed at a distance of 500mm from the tank top. A water outlet pump is arranged in the clean water tank.

The water outlet pump is a submersible sewage pump, the flow is equal to the flow of the biogas slurry inlet lifting pump at the front end, and the lift is determined according to the pipeline loss and the height difference from the water outlet to the biochemical treatment tank. The water outlet pump is controlled in linkage with the liquid level meter 51.

The liquid level meter is arranged in the clean water tank, the water outlet pump and the liquid level meter are controlled in a linkage mode, the high water level starts the pump, and the low water level stops the pump.

A pretreatment systems for kitchen biogas slurry is equipped with the mud collecting vat, and the mud collecting vat is 3, divides to establish pushing down filter vat, oil extraction groove, air supporting groove bottom, collects the mud and the dross in each groove. The height of the sludge collecting tank is 500m, the angle of the bevel edge is 50-60 DEG, and the sludge is deposited at the bottom of the sludge collecting tank along the bevel edge. The sludge collecting tank is provided with a sludge discharge valve 91 at the bottom of the side edge.

The mud valve is a butterfly valve of DN 100. And the sludge collecting tanks are respectively positioned below the pressure filtering tank, the oil separating tank and the air floating tank. And opening a butterfly valve, and collecting the sludge through a pipeline to a sludge dewatering system for treatment.

The pretreatment system for kitchen biogas slurry is provided with 4 emptying valves 92, which are butterfly valves of DN 80. The bottoms of the sides of the pressure filtering tank, the oil separating tank, the air floating tank and the clear water tank are respectively arranged. And opening the butterfly valve to drain the sewage in each tank through the pipeline.

And an overrunning valve control is arranged on the overrunning pipe. The overrunning valve is 2 butterfly valves which are respectively arranged on the water inlet pipe and the overrunning pipe. Normally, an overrun valve on the overrun pipe is closed, an overrun valve on the water inlet pipe is opened, and biogas slurry enters the first chemical feeding groove. When the spiral shell machine is out of order or the effluent SS (suspended solids) is not high, the overrun valve on the water inlet pipe is closed, the overrun valve on the overrun pipe is opened, and the sewage overrun filter pressing groove enters the oil separating groove.

A pretreatment systems for kitchen biogas slurry establishes the gas collecting channel, and the gas collecting channel parcel is collected the foul smell in the top of whole pretreatment equipment. The gas collecting hood can be made of glass fiber reinforced plastic, and has a height of 500mm and is detachable.

A preprocessing system for kitchen natural pond liquid establishes cat ladder, and cat ladder width 800mm highly is according to the whole altitude mixture control of equipment, and the people stands when the cat ladder, can observe the inside running condition of equipment to overhaul in the entering equipment. Meanwhile, the lower part of the crawling ladder is also provided with an equipment operation space.

Finally, it should be noted that, although the embodiments have been described in the text and the drawings, the scope of the utility model is not limited thereby. The technical scheme generated by replacing or modifying the equivalent structure or equivalent flow by utilizing the content recorded in the text and the drawings of the specification based on the essential idea of the utility model, and the technical scheme of the embodiment directly or indirectly implemented in other related technical fields are included in the patent protection scope of the utility model.

Claims (10)

1. A pretreatment system for kitchen biogas slurry is characterized by comprising a first dosing tank, a spiral shell stacking filter press, an oil separation tank, a second dosing tank, an air floatation tank and a clear water tank which are sequentially arranged along the trend of water flow,

the first dosing tank is externally connected with sewage, the feed inlet of the spiral filter press is connected with the discharge outlet of the first dosing tank, the discharge outlet of the spiral filter press is connected with the feed inlet at the bottom of the oil separating tank, a partition plate and an oil absorption assembly are arranged in the oil separating tank, the partition plate is vertically connected to the bottom of the oil separating tank, the oil absorption assembly is transversely connected to the notch of the oil separating tank, the height of the oil absorption assembly is higher than the top of the partition plate, and sewage entering the oil separating tank overflows from one side of the partition plate to the other side of the partition plate;

the air floatation tank is connected with an air dissolving device, and a slag scraping machine is arranged at the notch of the air floatation tank;

the first dosing tank and the second dosing tank are internally provided with stirrers.

2. The pretreatment system for kitchen slurry as recited in claim 1, wherein: the oil absorption assembly comprises a winding rod and oil absorption cotton wound on a roll shaft, and an oil absorption cotton mounting opening is formed in one side of the roll shaft.

3. The pretreatment system for kitchen slurry as recited in claim 1, wherein: the pretreatment system further comprises a filter pressing groove, and the first dosing groove and the spiral shell stacking filter press are arranged in the filter pressing groove.

4. A pretreatment system for kitchen slurry as claimed in claim 3, wherein: the bottom of the pressure filter tank, the oil isolation tank and the air floatation tank are all provided with a sludge collecting tank.

5. A pretreatment system for kitchen slurry as claimed in claim 3, wherein: the slag scraping machine is connected with a slag discharging pipe, and a discharge hole of the slag discharging pipe is connected into a sludge collecting tank at the bottom of the air floatation tank.

6. A pretreatment system for kitchen slurry as claimed in claim 3, wherein: the pretreatment system further comprises a gas collecting hood, wherein the gas collecting hood is arranged above the pressure filtering tank, the oil isolating tank, the air floating tank and the clear water tank, and the gas collecting hood is externally connected with an odor treatment system.

7. The pretreatment system for kitchen slurry as recited in claim 1, wherein: the baffle is close to the feed inlet setting of oil groove bottom.

8. The pretreatment system for kitchen slurry as recited in claim 1, wherein: the first dosing tank comprises two dosing grids, the two dosing grids are respectively used for adding PAC and PAM, and stirrers are arranged in the two dosing grids;

the structure of the second dosing tank is the same as that of the first dosing tank.

9. The pretreatment system for kitchen slurry as recited in claim 1, wherein: the pretreatment system further comprises an overrun pipe, one end of the overrun pipe is externally connected with sewage, and the other end of the overrun pipe is communicated with the oil separation groove.

10. The pretreatment system for kitchen slurry as recited in claim 1, wherein: the pretreatment system further comprises a water outlet pump, wherein the water outlet pump is arranged in the clean water tank, and the water outlet pump is externally connected with the biochemical tank.