A kitchen waste slurry filtering device

Abstract

The embodiment of the application relates to the field of environmental protection technology, and discloses a kind of kitchen garbage slurry filtering equipment, the kitchen garbage slurry filtering equipment includes: first screen, first screen has multiple first screen holes, first screen hole is used to filter kitchen garbage slurry and obtain first filtrate;Overflow weir plate, be located below first screen, for receiving first filtrate, outlet weir is equipped on overflow weir plate;Second screen, be located below overflow weir plate, the screen surface of second screen is single curved surface, the straight line side of single curved surface is aligned with outlet weir, for receiving the first filtrate overflowed at outlet weir;Second screen has multiple second screen holes, second screen hole area is less than first screen hole area, second screen hole is used to filter first filtrate when first filtrate flows along the arc direction of single curved surface.Through the above manner, the embodiment of the application realizes the effect of improving the filtration of kitchen garbage slurry.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of environmental protection, in particular to a filter equipment for kitchen waste slurry. BACKGROUND

[0002] Kitchen waste refers to the garbage generated in daily life, food processing, catering services, and unit catering activities, including discarded vegetable leaves, leftovers, fruit peels, eggshells, tea dregs, and bones, etc. Its main sources are household kitchens, restaurants, hotels, canteens, markets, and food processing-related industries.

[0003] The slurry generated in the pretreatment process of kitchen waste (including catering waste, household kitchen waste, and other kitchen waste) mainly includes hopper and equipment dewatering, solid-liquid separation slurry, and slurry separated by three-phase oil extraction machines. Such slurry has high solid content, high grease content, viscous slurry, and many long fiber plastics and other impurities. The commonly used filter and impurity removal equipment in the kitchen waste pretreatment field aims to prevent the three-phase oil extraction machine from being blocked, and generally uses a centrifugal degritting machine with a filter screen hole of about 5mm. However, the current kitchen waste slurry preparation of carbon source as a new resource utilization method uses membrane filtration to prepare carbon source, as disclosed in Chinese patents CN116553642A, CN118307134A, and CN221117047U. However, long impurities need to be filtered out before membrane filtration to prevent damage to the membrane element and blockage of the membrane tube. Due to the requirements of membrane feeding, the particle size of the material should be ≤1mm, and of course the smaller the particle size of the material, the more conducive to the continuous and stable operation of the membrane system.

[0004] The existing technology usually uses one layer of filter screen to filter the slurry of kitchen waste, and the filtrate obtained still contains a large amount of solid impurities, which is difficult to meet the feeding requirements of the membrane system.

[0005] Therefore, how to improve the filtration effect of kitchen waste slurry has become a technical problem to be solved. SUMMARY

[0006] In view of the above problems, the embodiments of the present application provide a filter equipment for kitchen waste slurry, which is used to improve the filtration effect of kitchen waste slurry.

[0007] According to an aspect of the embodiments of the present application, a filtering device for filtering kitchen waste slurry is provided, which comprises: a first screen having a plurality of first screen holes for filtering the kitchen waste slurry to obtain a first filtrate; an overflow weir plate arranged below the first screen for receiving the first filtrate, the overflow weir plate being provided with an outlet weir; a second screen arranged below the overflow weir plate, the screen surface of the second screen being a single curved surface, the straight line edge of one side of the single curved surface being aligned with the outlet weir for receiving the first filtrate overflowing from the outlet weir; the second screen having a plurality of second screen holes, the area of the second screen holes being smaller than the area of the first screen holes, the second screen holes being used for filtering the first filtrate when the first filtrate flows along the arc direction of the single curved surface.

[0008] Preferably, the first screen and the second screen are both wedge-shaped screens, and the long side of the second screen hole is perpendicular to the direction of gravity.

[0009] Preferably, the arc of the single curved surface is in the shape of a brachistochrone curve.

[0010] Preferably, the filtering device further comprises a driving assembly; the first screen is in the shape of a cylinder and is connected to the driving assembly for rotating under the driving of the driving assembly to filter out the first solid impurities in the kitchen waste slurry to obtain the first filtrate; one end of the first screen is provided with an inlet for inputting the kitchen waste slurry, and the other end is provided with an outlet for outputting the first solid impurities; the first screen is provided with a spiral blade inside, the spiral blade having a blade axis which is coaxial with the central axis of the cylinder and is attached to the inner wall of the first screen for conveying the first solid impurities to the outlet.

[0011] Preferably, the pitch of the part of the spiral blade close to the outlet is greater than the pitch of the part of the spiral blade close to the inlet.

[0012] Preferably, an included angle is formed between the central axis of the first screen and the horizontal plane, the included angle being in the range of 0-10°, and the outlet is higher than the inlet.

[0013] Preferably, the second screen is used for filtering out the second solid impurities in the first filtrate to obtain a second filtrate; the filtering device further comprises a filtrate receiving tank and a material receiving tank, the filtrate receiving tank being arranged below the second screen and being used for receiving the second filtrate, and the material receiving tank being arranged close to the straight line edge of the other side of the second screen and being used for collecting the second solid impurities sliding off the second screen.

[0014] Preferably, the filtering device further comprises: a plurality of flushing nozzles distributed along the central axis direction of the first screen and fixed to the obliquely upper side of the first screen; and a flushing spray gun arranged above the side of the second screen.

[0015] Preferably, the filtering device further comprises a water baffle arranged close to the inlet.

[0016] Preferably, the filtering device further comprises: a water inlet pipe connected to the filtrate receiving tank; a plurality of water outlet pipes respectively connected to the flushing lance and the plurality of flushing nozzles; and a solenoid valve connected to the water inlet pipe, configured to draw the second filtrate from the filtrate receiving tank and deliver the drawn second filtrate to the plurality of water outlet pipes.

[0017] The first screen hole of the first screen is used to filter the solid impurities with large volume in the kitchen waste slurry to obtain the first filtrate, and the second screen hole with smaller area than the first screen hole on the second screen is used to filter the long strip impurities with small volume in the first filtrate, so that the fine filtration of the kitchen waste slurry is realized through the layered arrangement of the first screen and the second screen, thereby improving the filtration effect of the kitchen waste slurry; the screen surface of the second screen is set as a single curved surface, so that the first filtrate can flow naturally on the single curved surface under the action of gravity when the first filtrate is filtered through the second screen, and the first filtrate can still flow along the arc direction of the single curved surface under the action of gravity in the case that part of the second screen holes on the single curved surface are blocked, so that the filtration is realized through the unblocked second screen holes on the single curved surface, thereby improving the utilization rate of the screen holes of the second screen and the filtration efficiency; the overflow weir plate is arranged between the first screen and the second screen, and the straight line edge on one side of the single curved surface is arranged horizontally and aligned with the outlet weir of the overflow weir plate, so that the first filtrate overflowing at the outlet weir can be evenly spread on the second screen, the filtration area of the second screen is fully utilized, and the first filtrate can flow from the straight line edge on one side of the single curved surface to the straight line edge on the other side, so that the flow path of the first filtrate on the single curved surface is prolonged, thereby improving the utilization rate of the second screen holes on the second screen and fully utilizing the filtration area of the second screen.

[0018] The above description is only a summary of the technical solutions of the present application, in order to enable the technical means of the present application to be implemented more clearly according to the content of the description, and in order to enable the above and other purposes, characteristics and advantages of the present application to be more obvious and easy to understand, the following specific embodiments of the present application are described. BRIEF DESCRIPTION OF DRAWINGS

[0019] Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The accompanying drawings are merely illustrative and are not considered to be limiting upon the present application. Furthermore, like reference numerals denote like parts throughout the drawings. In the drawings:

[0020] Fig. 1 A perspective view of the filtering device provided by the embodiment of the present application is shown;

[0021] Fig. 2 Another perspective view of the filtering device provided by the embodiment of the present application is shown;

[0022] Fig. 3 Fig. 5 shows a partial internal structure schematic diagram of the filtering device provided by the embodiment of the present application;

[0023] Fig. 4 Fig. 6 shows a cross-sectional view of the filtering device provided by the embodiment of the present application;

[0024] Fig. 5 Fig. 7 shows a side view of the filtering device provided by the embodiment of the present application;

[0025] Fig. 6 Fig. 8 shows another partial internal structure schematic diagram of the filtering device provided by the embodiment of the present application.

[0026] The reference signs in the detailed description are as follows:

[0027] 101, feed pipe; 102, feed distribution chute; 103, overflow weir chute; 104, support angle steel; 105, water baffle; 106, flushing water baffle;

[0028] 201, first screen; 202, spiral blade; 203, front support roller of roller; 204, roller limiting ring; 205, drive reduction motor; 206, large gear; 207, small gear; 208, drive chain; 209, discharge port; 210, overflow weir plate; 211, gear water baffle; 212, rear support roller of roller;

[0029] 301, second screen; 302, filtrate receiving chute; 303, material receiving chute; 304, undersize filtrate outlet; 305, oversize material outlet;

[0030] 401, flushing pump; 402, flushing pipeline; 403, flushing nozzle; 404, flushing spray gun; 405, electromagnetic valve;

[0031] 501, adjustable support leg; 502, cross beam; 503, equipment sealing shell; 504, quick-opening access hole; 505, quick-opening observation port; 506, quick-opening door; 507, deodorization port;

[0032] 6, maintenance platform. DETAILED DESCRIPTION

[0033] The embodiments of the technical solutions of the present application will be described in detail below with reference to the drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present application, and therefore only serve as examples, and cannot limit the protection scope of the present application.

[0034] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of this application; the use of the terms "including," "comprising," or "having" and variations thereof herein is intended to be broad and encompass the terms "consisting of" and "consisting essentially of" and variations thereof. Unless otherwise required by context, singular terms shall include pluralities and vice versa. Unless otherwise required by context, the use herein of the singular is also to be construed as a reference to the plural and vice versa.

[0035] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise explicitly and specifically limited.

[0036] Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearance of the phrase in various places in the specification does not necessarily all refer to the same embodiment, nor is it necessarily independent or alternative embodiments to each other. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0037] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B, which can represent the three cases of A existing, A and B existing, and B existing. In addition, the character " / " in this paper generally represents that the front and rear associated objects are a "or" relationship.

[0038] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two), and similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0039] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the embodiments of the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the embodiments of the present application.

[0040] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, the technical terms "mounting", "connecting", "connecting", "fixing" and other terms should be understood in a broad sense, for example, can be fixedly connected, or can be detachably connected, or can be integrated; can be mechanically connected, or can be electrically connected; can be directly connected, or can be indirectly connected through an intermediate medium; can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0041] Please refer to Figs. 1-6 The embodiments of the present application provide a filtering device for filtering kitchen waste slurry, which comprises: a first screen 201, the first screen 201 has a plurality of first screen holes, the first screen holes are used for filtering the kitchen waste slurry to obtain a first filtrate; an overflow weir plate 210 arranged below the first screen 201, used for receiving the first filtrate, the overflow weir plate 210 is provided with an outlet weir; a second screen 301 arranged below the overflow weir plate 210, the screen surface of the second screen 301 is a single curved surface, the straight line edge of one side of the single curved surface is aligned with the outlet weir, used for receiving the first filtrate overflowing at the outlet weir; the second screen 301 has a plurality of second screen holes, the area of the second screen holes is smaller than the area of the first screen holes, and the second screen holes are used for filtering the first filtrate when the first filtrate flows along the arc direction of the single curved surface.

[0042] The feed water distribution assembly comprises a feed pipe 101, a feed distribution groove 102, an overflow weir groove 103, a support angle steel 104, a water baffle 105 and a flushing water baffle 106. The feed pipe 101 penetrates the feed port of the first screen 201, the kitchen waste slurry enters the inside of the first screen 201 through the feed pipe 101, the end of the feed pipe 101 is connected to the square feed distribution groove 102, the overflow weir groove 103 is arranged on both sides of the feed distribution groove 102, and the overflow weir groove 103 can be arranged horizontally to uniformly overflow the kitchen waste slurry at the outlet weir, so that the kitchen waste slurry is uniformly spread on the screen surface of the first screen 201.

[0043] The feed pipe 101 and the feed distribution groove 102 can be integrated by welding. Preferably, the insertion depth of the feed pipe 101 is 1 / 3-1 / 2 of the length of the first screen 201. Since the feed pipe 101 is inserted deep into the first screen 201, the feed distribution groove 102 can be fixed on the cross beam 502 by the support angle steel 104. Moreover, using the support angle steel 104 as a support component can prevent the screened sundries (first solid impurities) from accumulating on the support component during the rotation of the first screen 201, and prevent the material from corroding the support component and the material from deteriorating; further, the water baffle 105 can prevent the feed from returning out of the first screen 201 under the flushing of the flushing nozzle 403.

[0044] The upper filtering assembly comprises a first screen 201, a spiral blade 202, a front drum supporting roller 203, a drum limiting ring 204, a driving reduction motor 205, a large gear 206, a small gear 207, a driving chain 208, a discharge port 209, an overflow weir plate 210, a gear water baffle 211, and a rear drum supporting roller 212.

[0045] The kitchen waste slurry overflowing from the overflow weir groove 103 is evenly spread on the first screen 201 rotating at a slow and uniform speed, and the materials smaller than the size of the first screen hole fall into the second screen 301 through the first screen hole. The materials larger than the size of the first screen hole are intercepted in the first screen 201. The first screen 201 is in a cylindrical shape and forms a drum under the driving of the driving assembly. The first screen 201 is uniformly distributed with the first screen hole around the circumference. The first screen hole is in the form of a wedge-shaped mesh, which has a long side and a short side. The short side of the wedge-shaped mesh is called a gap, which is generally 3-5 mm. The gap of the first screen hole of the first screen 201 is larger than that of the second screen hole of the second screen 301. Through the combination of the first screen hole of the first screen 201 and the second screen hole of the second screen 301, the screen clogging time can be greatly prolonged to achieve fine filtration of the kitchen waste slurry.

[0046] The end surface of the first screen 201 is welded with the large gear 206. The large gear 206 is connected with the small gear 207 through the driving chain. The small gear 207 rotates through the driving reduction motor 205, thereby driving the large gear 206 and the first screen 201 to rotate. The driving reduction motor 205 is a variable frequency motor. The rotating speed of the first screen 201 is slow, which is 4-10 rpm. The rotating speed can be adjusted according to the content of the impurities in the kitchen waste slurry. The faster the rotating speed, the faster the speed of discharging the impurities.

[0047] The spiral blade 202 is fixedly welded to the inner side of the first screen 201. The spiral blade 202 can be continuous or discontinuous. When the first screen 201 rotates, the first solid impurities are thrown up or fall down by beating. The fallen first solid impurities are smoothly discharged from the first screen 201 into the discharge port 209 with the cooperation of the spiral blade 202. The pitch of the spiral blade 202 can be gradually increased in the discharging direction to quickly discharge the first solid impurities from the discharge port 209.

[0048] The first screen 201 is supported by rollers, which include two groups of front drum supporting rollers 203 and rear drum supporting rollers 212. The position of the first screen 201 is stabilized by the cooperation of the drum limiting ring 204. The included angle α between the central axis of the first screen 201 and the horizontal plane is 0-10°. For example, when there is no requirement for the moisture content of the discharged impurities, the included angle α can be set to 0°. When the included angle α increases, the probability of short flow of the raw materials can be reduced, and the residence time of the impurities in the drum screen can be increased to reduce the moisture content of the impurities.

[0049] Gear water baffle 211 is arranged on the side of the drum limiting ring 204 close to the first screen 201, to prevent slurry from polluting the gear, prolong the service life of the gear wheel 206, pinion 207 and drive chain, and avoid the situation of running, leaking and dripping of the filtering equipment.

[0050] The first filtrate flows into the lower filtering assembly through the overflow weir plate 210, and the lower filtering assembly comprises a second screen 301, a filtrate receiving tank 302, a material receiving tank 303, a screen underflow outlet 304, a screen over material outlet 305, and a second filter hole. The width of the overflow weir plate 210 is consistent with the width of the second screen 301, and the overflow weir plate 210 is adjusted to a horizontal state by the bolt and nut of the base, so that the first filtrate is evenly spread on the uppermost end of the entire second screen 301, ensuring that every part of the second screen 301 has material passing through, and fully utilizing the filtering area of the arc-shaped single curved surface screen.

[0051] The second screen 301 can separate the second filtrate and the second solid impurities (long strip fibers, plastics and other sundries) in the first filtrate by gravity. The second screen 301 is in the form of a wedge-shaped screen, and the wedge-shaped screen hole has a long side and a short side. The long side of the wedge-shaped screen hole is arranged perpendicular to the direction of gravity, so that the long side of the wedge-shaped screen hole is perpendicular to the direction of water flow, that is, when the general long strip sundries flow with the water flow, the long side of the sundries is parallel to the direction of water flow, so that it is easier to be intercepted by the second screen hole. The short side of the wedge-shaped screen hole is called a gap, and the gap is required to be ≤1mm according to the water inlet requirement of the membrane system. The side curve of the second screen 301 is preferably an arc close to the fastest curve (the curve speed between two points is faster than the straight line speed), so as to ensure a faster water flow speed, facilitate the sundries on the screen surface of the second screen 301 to be washed into the material receiving tank 303, and the second filtrate to enter the material receiving tank 303. The filtrate receiving tank 302 and the material receiving tank 303 are respectively provided with a screen underflow outlet 304 and a screen over material outlet 305.

[0052] Alternatively, the first screen 201 and the second screen 301 can be cleaned by a scraper and a brush. However, the brush needs to be replaced regularly, and the scraper inside the screen cannot scrape out the fiber material, so the screen is easily blocked by sundries, and therefore the filtering efficiency of the filtering equipment needs to be improved.

[0053] Therefore, the first screen 201 and the second screen 301 can be cleaned by flushing, and the second filtrate in the filtrate receiving tank 302 can be used as a water source to flush the first screen 201 and the second screen 301, so as to save resources and filter the second filtrate again, thereby improving the filtering effect.

[0054] The screen flushing assembly comprises a flushing pump 401, a flushing pipeline 402, a flushing nozzle 403, a flushing spray gun 404 and an electromagnetic valve 405.

[0055] With the continuous filtering of the material, impurities will inevitably adhere to the surface of the screen and block the screen. Therefore, a flushing pump 401 can be provided fixed to the back of the filtrate receiving tank 302, taking the second filtrate as the flushing water source, greatly reducing the consumption of tap water, and without increasing the amount of filtrate. The flushing water is delivered to the flushing nozzle 403 and the flushing spray gun 404 through the flushing pipeline 402, and the flushing frequency and flushing time of the flushing nozzle 403 can be controlled by the electromagnetic valve 405. The flushing nozzle 403 backwashes the first screen 201, and the nozzle of the flushing nozzle 403 is attached to the flushing pipeline 402 and fixed to the upper side of the first screen 201. The number of nozzles is determined according to the length of the first screen 201, so that the backwash water can cover the entire screen. Generally, the interval is 300-600 mm, and the nozzle adopts a spiral nozzle suitable for flushing water containing impurities. With the rotation of the first screen 201, the impurities adhering to the first screen hole of the first screen 201 can be cleaned and discharged to the discharge port 209 along the spiral blade 202. The backwashing process can be carried out under the conditions of rotation and stop of the first screen 201, without affecting the filtering process.

[0056] A flushing baffle 106 is provided on the inner side of the first screen 201 near the discharge port 209, and the flushing baffle 106 is fixed to the feed cloth tank 102 to prevent the backwash water from being directly sprayed onto the discharged impurities, thereby improving the dryness of the discharged impurities.

[0057] The flushing spray gun 404 performs forward flushing on the second screen 301, and the interface of the flushing spray gun 404 is provided on the upper side of the second screen 301. The arc-shaped screen is also manually cleaned regularly according to the screen clogging condition, generally after the filtering equipment is stopped, which can prevent the organic solid from being hardened and clogging the screen surface.

[0058] The outer shell of the filtering equipment is provided with adjustable legs 501, cross beams 502, equipment sealing shell 503, quick-opening maintenance opening 504, quick-opening observation opening 505, quick-opening door 506, and deodorizing opening 507. The adjustable legs 501 and cross beams 502 serve as support structure components of the outer shell and internal screen, and also as support structure components of the maintenance platform 6. In order to facilitate maintenance and replacement of the screen, the top cover of the upper filtering assembly is rivet-fixed, and the joint is provided with a baffle seal to prevent slurry from leaking out. The lower second screen 301 can be opened and replaced through the side-opening quick-opening door 506, and the sealing and butt joint of the quick-opening door 506 are provided with a baffle seal to prevent slurry from leaking out.

[0059] The quick-opening observation opening 505 or the quick-opening maintenance opening 504 is provided above the discharge port 209 of the first screen 201 and above the flushing nozzle 403, and the top cover of the first screen 201 is provided with a DN100 deodorizing opening 507 to prevent odor from escaping. The outer shells of movable components such as support rollers, drive chains, and pinions are rivet-assembled, which can be quickly disassembled for maintenance.

[0060] The maintenance platform 6 is composed of a maintenance platform and a ladder, and the adjustable supporting legs 501 and the cross beams 502 are used as supporting structural members. The maintenance platform 6 is arranged on both sides of the upper filter assembly, so as to facilitate observation of the filtration and clogging conditions of the first screen 201, observation of the backwashing condition, and maintenance of the internal parts of the filter equipment.

[0061] The application adopts an integrated device composed of upper and lower screen meshes to finely filter long fibers, plastics and other sundries in kitchen garbage slurry, so as to meet the feeding requirements of the membrane system in the carbon source preparation device. The kitchen slurry is first filtered through the first screen mesh 201 in the form of a roller, and the larger first screen hole can obtain higher flux and longer plugging time. At the same time, the slow rotating first screen mesh 201 can throw or knock down the sundries adhered to the mesh hole, and the sundries are timely discharged through the spiral blade 202 inside the first screen mesh 201, which also prolongs the plugging time. The filtrate after the removal of sundries by the upper filtration assembly has a reduced solid content, which creates good conditions for the subsequent arc-shaped second screen mesh 301 with higher filtering precision. The first filtrate preliminarily removed by the first screen mesh 201 in the form of a roller enters the second screen mesh 301, which uses the principle of the brachistochrone curve (the speed of an object moving on the brachistochrone curve between two points under the action of gravity is the fastest) to flush the sundries retained in the second screen mesh 301 to the material receiving groove 303 through the rapid flow of fluid. The feeding size, solid content and viscosity of the sundries are different for the two kinds of screen meshes, and the two kinds of screen meshes play the best role and form a complement to each other according to their own principles, avoiding the problems of easy plugging of the single first screen mesh 201, difficult flushing of the single second screen mesh 301 due to viscosity, and poor flowability of the first filtrate on the second screen mesh 301, thereby avoiding the problem of inability to continuously and stably operate. Specifically, the coarse screen hole gap of the first screen hole is 3-5 mm, and the fine screen hole gap of the second screen hole is ≤1 mm. The combined filtration can make the kitchen garbage slurry with high viscosity, long fiber and plastic sundries meet the water feeding requirements of the membrane system. The filtering device has the advantages of high filtering precision, non-plugging screen mesh, large processing capacity, and continuous and long-term stable operation, and can be used for the sundry removal pretreatment of slurry generated by kitchen garbage equipment (such as a three-phase oil extractor), and can meet the sundry removal and filtration under different slurry solid content, sundry content and viscosity. The particle size of the particles and sundries in the filtrate under the second screen mesh 301 is small, and the second screen mesh 301 is used as a backwashing water source to automatically clean the first screen mesh 201 and the second screen mesh 301 at regular intervals, which greatly prolongs the plugging time of the screen mesh and basically realizes manual cleaning. The backwashing can be performed during the filtration process, which also increases the processing capacity of the device and realizes continuous and stable operation. The low-speed rotating first screen mesh 201 and the gravity-dependent second screen mesh 301 have lower energy consumption and screen mesh wear than the high-speed centrifugal filtration method, and do not need to frequently replace consumable parts, do not need external tap water flushing, and basically do not need manual cleaning. Overall, the operation cost of the device is very low. The overflow weir plate 210 is a key component for connecting the two kinds of filtration screen meshes, which ingeniously combines the two kinds of filtration screen meshes together, and the device has high intensity and small floor area.

[0062] The slurry generated in the pretreatment process of kitchen waste has a hopper and equipment (mainly a screw) draining water, solid-liquid separation slurry, and slurry separated by three-phase oil extraction. The filtering equipment can process various types of slurry in the pretreatment process of kitchen waste. The slurry is pumped to the water inlet pipe, and then overflows from the water inlet pipe to the feed distribution tank 102. The area of the feed distribution tank 102 is larger than the horizontal projection area of the water inlet pipe, so the water flow velocity can be reduced, and the horizontal overflow weir tank 103 on both sides of the feed distribution tank 102 can overflow, and the slurry is evenly spread on the first screen 201.

[0063] The first screen 201 is selected as a wedge-shaped screen with a mesh gap of 3-5 mm. When processing the draining water of the hopper and equipment, the mesh gap is set to 5 mm because there are many large-sized impurities in the material. The area of the first screen 201 needs to be appropriately enlarged. When processing the slurry after three-phase oil extraction, the impurities in the material have been pretreated, and the impurity content is relatively low, so the mesh gap can be selected as 3 mm. The wedge-shaped mesh has higher opening rate, better structural strength, and lower manufacturing cost compared to the circular mesh.

[0064] The first screen 201 is driven by a drive reduction motor 205 to drive a pinion gear 207, which drives a large gear 206 through a drive chain 208. The large gear 206 is fixed to the first screen 201 by bolt welding, so it drives the first screen 201.

[0065] The rotation speed of the first screen 201 is 4-10 rpm, which can be adjusted by a variable frequency motor. After the raw material enters the first screen 201, the material smaller than the first screen size falls into the overflow weir plate 210. The impurities on the screen are thrown up and dropped down by the rotating action of the first screen 201. The impurities are discharged to the discharge port through the spiral blade 202 welded to the inner wall of the first screen 201, and the upper filtration process is completed.

[0066] When processing the draining water of the hopper and equipment with high impurity and solid content, the first screen 201 rotates at a speed of 8-10 rpm to increase the impurity conveying capacity and discharge the impurities from the first screen 201 faster. The higher speed reduces the dryness of the discharged impurities. When processing the three-phase oil extraction slurry with low impurity and solid content, the first screen 201 rotates at a lower speed of 4-6 rpm, and the lower speed reduces the energy consumption of the equipment. Due to the lower speed of the first screen 201, the moisture content of the discharged impurities is between 85% and 90%, and the discharged impurities still contain a high content of organic matter, which can be treated by an anaerobic digestion system or further improved by a squeezing device.

[0067] When the impurity material requires higher dryness, the first screen 201 can be set to be inclined, that is, the inlet is lower than the outlet 209, and the angle between the central axis of the first screen 201 and the horizontal plane is set to 10°, which reduces the probability of short flow of the material and prolongs the residence time of the material in the first screen 201, so that the moisture content of the impurity material is between 83-88%.

[0068] The first filtrate obtained by the upper filtration is temporarily stored in the overflow weir plate 210, the width of the overflow weir plate 210 is the width of the first screen 201, and the shell of the filtration equipment is used as the shell of the overflow weir plate 210. By adjusting the height of the bolt and nut of the adjustable leg 501 base, the levelness of the outlet weir of the overflow weir plate 210 is strictly controlled, so that the first filtrate is uniformly spread on the entire second screen 301.

[0069] The second screen 301 is a wedge-shaped screen with a mesh gap of 1 mm, and the long side of the wedge-shaped mesh is perpendicular to the water flow direction, which can remove most of the long fibers and plastic impurities, and obtain a filtrate that meets the water inlet requirements of the membrane system. The curvature of the second screen 301 is preferably close to the fastest curve, which can form the fastest water flow speed to flush the impurities on the screen surface to the material receiving groove 303, and then discharge the equipment through the outlet of the material receiving groove 303. During operation, adjusting the appropriate raw material flow is an important condition to ensure the flushing speed and effect.

[0070] During debugging and operation, the maintenance platform 6, quick-opening observation port 505 and quick-opening door 506 are needed to observe the mesh clogging and impurity removal of the first screen 201 and the second screen 301, and to determine the appropriate first screen 201 rotating speed, backwashing time and backwashing frequency. The flushing frequency and time are controlled by the electromagnetic valve. The equipment can be backwashed online without stopping, which prevents the screen holes of the first screen 201 and the second screen 301 from being clogged and unable to filter normally, thereby ensuring the long-term continuous and stable operation of the filtration equipment.

[0071] The screen flushing assembly includes a flushing pump 401, a flushing pipeline 402, a flushing nozzle 403, a flushing spray gun 404 and an electromagnetic valve 405. The flushing pump 401 uses the second filtrate as the flushing water source, which is delivered to the flushing nozzle 403 through the flushing pipeline 402. The nozzle selects a spiral nozzle, which has a larger flow passage and better resistance to impurities. The coverage radius of a single nozzle is about 300 mm, and the number of nozzles is preferably enough to cover the entire screen. The flow rate of a single nozzle is 15-20 L / min. Since no external tap water is introduced, the nozzle flushing flow rate can be appropriately increased to enhance the flushing effect.

[0072] When the equipment stops feeding, the flushing nozzle can be selected to continue flushing for 3-5 min, and the flushing spray gun 404 is used to flush the second screen 301 from the front, which prevents the organic solid from drying and clogging the screen surface.

[0073] The filter equipment is inspected during operation through the maintenance platform 600 and the quick-opening observation port 50, the quick-opening maintenance port 504, and the quick-opening door 056. When the filter equipment needs to be maintained or the screen is replaced, the first screen 201 can be replaced as a whole through the quick-opening door 506, and the first screen 201 can be hoisted and replaced as a whole through the quick-dismantling top cover plate, which is fast and simple.

[0074] The filter equipment is inspected during operation through the maintenance platform 600 and the quick-opening observation port 50, the quick-opening maintenance port 504, and the quick-opening door 056. When the filter equipment needs to be maintained or the screen is replaced, the first screen 201 can be replaced as a whole through the quick-opening door 506, and the first screen 201 can be hoisted and replaced as a whole through the quick-dismantling top cover plate, which is fast and simple.

[0075] In actual use, the kitchen waste slurry can be processed as follows: the drum screen grid gap is 3.5 mm, the first screen 201 gap is 1 mm, the first screen 201 drum rotating speed is 6 rpm, the first screen 201 inclination angle is 4°, and the backwashing frequency is 4 h / time, and the washing time is 3 min. Most of the long fibers and plastic impurities in the kitchen slurry can be removed, and the material size entering the membrane system is ≤1 mm, realizing the stable operation of the filter equipment and no phenomenon of clogging the screen hole. Through comparison, it is found that when the filter equipment is not used, the membrane system only filters impurities through the self-cleaning filter configured by itself, and the self-cleaning filter screen is blocked after only 8 h of operation, and the raw material cannot be fed into the membrane. When this equipment is used, the membrane system has not occurred self-cleaning filter mesh, membrane hole and membrane end face blockage, and the system runs smoothly. After 3 months of operation, the membrane equipment is disassembled, and it is found that only a small amount of long impurities are attached to the membrane end face, greatly increasing the stable operation time of the membrane system.

[0076] The first filter hole of the first screen 201 is used to filter the solid impurities with large volume in the kitchen garbage slurry to obtain the first filtrate, and the second filter hole with smaller area than the first filter hole on the second screen 301 is used to filter the long strip impurities with small volume in the first filtrate, so that the fine filtration of the kitchen garbage slurry is realized through the layered arrangement of the first filter screen and the second filter screen, thereby improving the filtration effect of the kitchen garbage slurry; the screen surface of the second screen 301 is set as a single curved surface, so that the first filtrate can flow naturally on the single curved surface under the action of gravity when the first filtrate is filtered through the second screen 301, and the first filtrate can still flow along the arc direction of the single curved surface under the action of gravity in the case that part of the second filter holes on the single curved surface are blocked, so that the filtration is realized through the second filter holes that are not blocked on the single curved surface, thereby improving the utilization rate of the filter holes and the filtration efficiency of the second filter screen; the overflow weir plate 210 is arranged between the first screen 201 and the second screen 301, and the straight line side of the single curved surface is arranged horizontally and aligned with the outlet weir of the overflow weir plate 210, so that the first filtrate overflowing at the outlet weir can be evenly spread to the second screen 301, so as to fully utilize the filtration area of the second screen 301, and the first filtrate can flow from the straight line side of the single curved surface to the straight line side of the other side, so as to prolong the flow path of the first filtrate on the single curved surface, thereby improving the utilization rate of the second filter holes on the second screen 301 and fully utilizing the filtration area of the second screen 301.

[0077] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should be covered in the scope of the claims and the specification of the present application. Especially, as long as there is no structural conflict, each technical feature mentioned in each embodiment can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A filtration device for filtering kitchen waste slurry, characterized in that, The filtration device includes: A first screen, having a plurality of first screen holes, the first screen holes being used to filter kitchen waste slurry to obtain a first filtrate; An overflow weir plate is located below the first screen and is used to receive the first filtrate. The overflow weir plate is provided with an outlet weir. The second screen is located below the overflow weir plate. The surface of the second screen is a single curved surface, and the straight edge of one side of the single curved surface is aligned with the outlet weir to receive the first filtrate overflowing from the outlet weir. The second screen has a plurality of second screen holes, the area of ​​which is smaller than that of the first screen holes. The second screen holes are used to filter the first filtrate when it flows along the arc direction of the single curved surface. The arc of the single-curved surface is in the shape of the fastest curve; The filtration device also includes a drive assembly; The first screen is cylindrical and connected to the drive assembly. It is used to rotate under the drive of the drive assembly to filter out the first solid impurities in the kitchen waste slurry to obtain the first filtrate. The first screen has a feed inlet at one end and a discharge outlet at the other end. The feed inlet is used to input the kitchen waste slurry, and the discharge outlet is used to output the first solid impurities. The first screen is provided with spiral blades, which are distributed on the inner wall of the first screen with the central axis of the cylinder as the blade axis, and are used to transport the first solid impurity to the discharge port. The second screen is used to filter out the second solid impurities in the first filtrate to obtain the second filtrate; The filtration device further includes a filtrate receiving tank and a material receiving tank. The filtrate receiving tank is positioned below the second screen and is aligned with it to receive the second filtrate. The material receiving tank is located near the straight edge of the other side of the second screen and is used to collect the second solid impurities that slide off the second screen. The filtration device also includes: Multiple rinsing nozzles are distributed along the central axis of the first screen and fixed to the upper oblique side inside the first screen. A rinsing spray gun is positioned above and to the side of the second screen. The filtration device also includes: The water inlet pipe is connected to the filtrate receiving tank; Multiple water outlet pipes are respectively connected to the flushing spray gun and the multiple flushing nozzles; A solenoid valve, connected to the inlet pipe, is used to extract the second filtrate from the filtrate receiving tank and transport the extracted second filtrate to the multiple outlet pipes.

2. The filtration device according to claim 1, characterized in that, Both the first screen and the second screen are wedge-shaped filters, and the long side of the second screen hole is perpendicular to the direction of gravity.

3. The filtration device according to claim 1, characterized in that, The pitch of the portion of the spiral blade near the discharge port is greater than the pitch of the portion of the spiral blade near the feed port.

4. The filtration device according to claim 1, characterized in that, The central axis of the first screen forms an angle with the horizontal plane, the angle being 0 to 10°, and the discharge port is higher than the inlet port.

5. The filtration device according to claim 1, characterized in that, The filtration device also includes a baffle plate, which is positioned near the feed inlet.

Images