A multi-stage screening device and method for removing organic matter

Abstract

A multi-stage screening device for removing organic matter and its usage method include a separation sedimentation chamber, into which a feed pipe and a high-pressure water inlet pipe extend. A jet plate is installed at the intersection of the feed pipe and the high-pressure water inlet pipe, so that the water in the high-pressure water inlet pipe mixes with the material in the feed pipe and is sprayed after passing through the jet plate. A jet cavity is set at the starting point of the jet to protect and guide the jet, and a guide cavity is set at the end of the jet direction to guide the jet into the ultrasonic cleaning zone of the separation sedimentation chamber. The ultrasonic cleaning zone includes an ultrasonic transducer and a space surrounded by the side wall that fixes the ultrasonic transducer. A low-speed water pipe is set below the ultrasonic cleaning zone to form an upward water flow zone in the ultrasonic cleaning zone. At least two multi-stage screening and conveying devices with different apertures are set below the upward water flow zone to filter the separated and settled sludge. A guide port is set at the water surface of the upward water flow zone, and the guide port is connected to a guide pipe to discharge the separated and floated organic matter.

Description

Technical Field

[0001] This invention relates to the field of sludge treatment technology, specifically to a multi-stage screening device for removing organic matter and its usage method. Background Technology

[0002] The maintenance and management of urban drainage pipe networks is a crucial part of comprehensive urban water environment management. Drainage sludge, a high-moisture solid waste generated during the dredging and maintenance of drainage pipe networks, is increasingly produced. If not cleaned up promptly, its accumulation in urban pipe networks will reduce the drainage cross-section, decrease drainage capacity, and even clog pipes, making urban flooding more likely during the rainy season. Besides its massive volume posing a threat to urban drainage pipe networks, drainage sludge is also diverse in origin and complex in composition, exhibiting different structures depending on natural and social factors. Generally, drainage sludge mainly consists of inorganic sand and gravel with SiO2 as its primary component, with low organic matter content. However, drainage sludge in sewage pipe networks or combined sewer systems often contains a higher proportion of organic matter and domestic waste.

[0003] The sludge removed from the drainage ditches is naturally dried before being sent to urban landfills for disposal. However, this method often causes secondary pollution such as groundwater contamination and odor. Therefore, it is necessary to classify and sort the sludge into household waste, coarse gravel, and medium and fine sand for resource utilization. Household waste can be incinerated together with urban waste. The separated coarse gravel can be used for roadbed materials or building materials, while the separated medium and fine sand can be further used as aggregate for brick making, ceramsite making, and other building materials, or as raw material for cement production, replacing the use of construction sand.

[0004] Currently, the screening of sewage sludge mainly relies on physical screening and washing, using devices such as washing drums and hydrocyclones for distribution screening. However, physical screening has limited ability to remove organic matter, and a certain thickness of organic flocs remains on the surface and between the separated fine sand, resulting in a high organic matter content. This has become a pain point and difficulty in further utilizing the sewage sludge after screening. Summary of the Invention

[0005] In view of this, and in response to the shortcomings of the existing technology, the purpose of this invention is to provide a multi-stage screening device for removing organic matter, which realizes multi-stage screening of sludge in drainage ditches by ultrasonic coupling jet method to enhance the removal of organic matter, and can achieve a more thorough stripping effect on organic components in drainage sludge and organic flocs on the surface of fine sand, while completing multi-stage screening of drainage sludge of different particle sizes.

[0006] This application aims to address one of the problems in the background art.

[0007] The technical solution adopted in this invention is as follows: In order to achieve the above-mentioned objectives and other related objectives, this invention provides a multi-stage screening device for removing organic matter;

[0008] A multi-stage screening device for removing organic matter includes a separation sedimentation chamber, into which a feed pipe and a high-pressure water inlet pipe extend. A jet plate is installed at the intersection of the feed pipe and the high-pressure water inlet pipe, so that the water in the high-pressure water inlet pipe mixes with the material in the feed pipe after passing through the jet plate and is sprayed. A jet cavity is provided at the starting point of the jet to protect and guide the jet, and a guide cavity is provided at the end of the jet direction to guide the jet into the ultrasonic cleaning zone of the separation sedimentation chamber. The ultrasonic cleaning zone includes an ultrasonic transducer and a space surrounded by a side wall that fixes the ultrasonic transducer.

[0009] A low-speed water pipe with a water inlet is installed below the ultrasonic cleaning zone. The water inlet is used to form an upward water flow zone within the ultrasonic cleaning zone. At least two multi-stage screening and conveying devices with different apertures are installed below the upward water flow zone to filter the separated and settled sludge. A guide port is installed at the water surface of the upward water flow zone. The guide port is connected to a guide pipe to discharge the separated and floated organic matter.

[0010] The technical solution provided in this application also has the following technical features:

[0011] Preferably, both the jet cavity and the guide cavity are funnel-shaped or cone-shaped.

[0012] Preferably, the aperture of the orifices distributed on the jet plate is 1-5 mm, including 1 and 5 mm.

[0013] Preferably, the multi-stage screening and conveying device is connected to a sludge pump, which sends the sludge into the sand-water separation tank. The filtered water after being treated by the screen is used for water supply in the high-pressure water inlet pipe or the low-speed water pipe.

[0014] Preferably, the jet plate has evenly distributed circular holes.

[0015] Preferably, the jet plate is circular.

[0016] Preferably, the initial pressure input into the high-pressure water inlet pipe is 30-40 kPa, including 30 and 40 kPa.

[0017] Preferably, the frequency of the ultrasonic transducer is 20-30 kHz, including 20 and 30 kHz, and the transmission period is 1.5-2 min, including 1.5 and 2 min.

[0018] Preferably, the mesh size of the screen or filter of the multi-stage screening conveying device is 10mm, 2mm, 0.1mm, or 0.075mm.

[0019] Preferably, the screen or filter screen of the sand-water separation tank has a pore size of 10mm, 2mm, 0.1mm, or 0.075mm.

[0020] Preferably, a multi-stage screening method for removing organic matter, used for screening organic matter in sludge, includes the following steps:

[0021] The sludge is initially separated by the jet and then sent through a pipe to the area above the high-pressure water jet. The jet direction of the high-pressure water jet after mixing with the sludge is set to gradually expand the jet cavity. The high-pressure water jet passes through the jet plate before mixing with the sludge. The jet plate is evenly provided with holes with a diameter of 1-5mm, including 1 and 5mm.

[0022] After being guided, the separated sludge jet falls into the separation chamber, where it is ultrasonically cleaned and naturally sinks under gravity. During the sinking process, it is mixed with the rising water flow, causing the light organic components to float to the surface and flow out along the guide port.

[0023] Preferably, the settled sludge is screened by a multi-stage screening and conveying device with different apertures and then sent to a sand-water separation tank. The sand-water separation tank is equipped with a screen, and the filtered water is used for jet or rising water flow.

[0024] Preferably, the jet cavity is funnel-shaped or conical.

[0025] Preferably, the sludge is pretreated and then subjected to organic matter screening, with the pretreatment being the removal of particles with a diameter greater than 5 mm.

[0026] The present invention has the following beneficial effects:

[0027] 1. When the high-pressure water of the present invention passes through the jet plate, it forms a high-pressure jet and creates a local vacuum. The organic matter and flocs on the surface of the sand and gravel in the sludge in the jet plate are attracted by the vacuum area. Under the synergistic effect of friction and collision of large particles, they are separated from the large sand and gravel. At the same time, they are impacted by the water flow onto the guide cavity and fall into the water under the action of gravity. The heavier sand and gravel sink, while the lighter organic components and sludge organic flocs float to the water surface under the action of the rising water flow and are discharged from the guide port.

[0028] 2. In this invention, the ultrasonic waves emitted by the ultrasonic transducer at 20-30 kHz can further clean the sinking sand and gravel under the action of oscillation and cavitation. It can effectively break down the organic flocs attached to the sand and gravel, and complete the secondary removal of inorganic sand and gravel and organic components from the ditch sludge. The broken organic components are discharged from the guide port with the rising water flow to the water surface.

[0029] 3. In this invention, the conveying device is combined with the screen to form a multi-stage screening and conveying device, which can realize the automation of screening and conveying work, is convenient to operate, saves process time, and realizes continuous screening operation.

[0030] 4. The device of the present invention has a simple structure. It integrates two washing methods, high-pressure jet and ultrasonic wave, with a multi-stage screening and conveying device to achieve the dual functions of coupled washing and multi-stage screening, and can also achieve continuous operation. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of a multi-stage screening device for removing organic matter according to the present invention;

[0032] Figure 2 This is a front view of the jet plate of a multi-stage screening device for removing organic matter according to the present invention;

[0033] Figure 3 This is a schematic diagram of the ultrasonic cleaning zone and the rising water flow zone of a multi-stage sieving device for removing organic matter according to the present invention.

[0034] In the picture:

[0035] 1. Feed pipe

[0036] 2. Ultrasonic transducer

[0037] 3. High-pressure water inlet pipe

[0038] 4. Jet cavity

[0039] 5. Jet plate

[0040] 6. Drainage pipe

[0041] 7. Multi-stage screening and conveying device

[0042] 8. Sludge pump

[0043] 9. Sand-water separation tank

[0044] 10. Screen

[0045] 11. Flow guiding cavity

[0046] 12. Low-speed water pipes

[0047] 13. Water outlet. Detailed Implementation

[0048] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. These embodiments are for illustrative purposes only and are not intended to limit the scope of the invention.

[0049] In the description of this invention, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0050] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0051] Furthermore, in the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0052] Example

[0053] like Figure 1-3 A multi-stage screening device for removing organic matter includes a separation sedimentation chamber, into which a feed pipe 1 and a high-pressure water inlet pipe 3 extend. A jet plate 5 is provided at the intersection of the feed pipe 1 and the high-pressure water inlet pipe 3, so that the water in the high-pressure water inlet pipe 3 is mixed with the material in the feed pipe 1 after passing through the jet plate 5 and sprayed. A jet cavity 4 is provided at the starting point of the spray to protect and guide the jet, and a guide cavity 11 is provided at the end of the spray direction to guide the jet into the ultrasonic cleaning zone of the separation sedimentation chamber. The ultrasonic cleaning zone includes an ultrasonic transducer 2 and a space surrounded by the side wall that fixes the ultrasonic transducer 2.

[0054] A water outlet 13 of a low-speed water pipe 12 is provided below the ultrasonic cleaning zone. The water outlet 13 is used to form an upward water flow zone in the ultrasonic cleaning zone. At least two multi-stage screening and conveying devices 7 with different apertures are provided below the upward water flow zone to filter the separated and settled sludge. A guide port is provided at the water surface of the upward water flow zone. The guide port is connected to the guide pipe 6 to discharge the separated and floated organic matter.

[0055] When implemented, this application features the following characteristics: it includes a separation sedimentation tank, inlets of a high-pressure water inlet pipe 3 and a low-speed water pipe 12, a feed pipe 1, a guide pipe 6 and a guide port, an ultrasonic transducer 2, a guide cavity 11, a jet plate 5, a jet cavity 4, a sludge pump, a sand-water separation tank 9, and a multi-stage screening and conveying device 7; the sludge from the drainage ditch is transported to the jet plate 5 through the feed pipe 1, and high-pressure water is introduced into the inlet. When passing through the jet plate 5, a high-pressure jet is formed, which initially separates the organic components of the sludge from the drainage ditch. After passing through the guide cavity 11, it flows into the cylinder and is subjected to ultrasonic treatment. After cleaning, the sludge from the drainage ditch settles due to gravity, while light substances such as organic components float to the surface under the influence of rising water flow and flow out through the guide port. The sludge then settles into a multi-stage screening and conveying device 7 equipped with filter screens of different pore sizes. After screening, components of different particle sizes are conveyed to a sand-water separation tank 9, which is equipped with filter screens. The filtered water is returned to the inlet. The multi-stage screening device and method for removing organic matter from drainage ditch sludge using ultrasonic coupled jet can effectively remove organic components attached to the sludge, enhancing the screening of sludge materials and subsequent resource utilization.

[0056] This invention employs an ultrasonic coupled jet method, eliminating the need for complex chemical agents or additives and avoiding reliance on chemical substances in traditional treatment methods. This simplifies operation and reduces the complexity of subsequent processing steps.

[0057] Compared to other processing methods, multi-stage screening devices and methods using ultrasonic coupled jets are less expensive; they do not require large amounts of energy or expensive equipment, and do not require frequent replacement of consumables; therefore, this technology is more economical in terms of implementation and maintenance.

[0058] Ultrasonic jets can effectively break down and disperse solid particles in sludge, enhancing contact and reaction with organic matter; combined with a multi-stage screening device, sludge can be continuously screened and separated, resulting in higher organic matter removal efficiency and better treatment effect.

[0059] The multi-stage screening and conveying device and the screen or filter screen in the sand-water separation tank are set with different pore sizes to achieve the step-by-step separation of solid particles of different sizes. Larger particles are screened out, while smaller particles pass through the screen or filter screen with fine pores, thus achieving a highly efficient separation effect. This helps to reduce the adhesion of organic matter to solid particles and improve the processing efficiency of the entire system.

[0060] Specifically, both the jet cavity 4 and the guide cavity 11 are trumpet-shaped or conical. This shape can enhance the jet effect and improve the processing efficiency. The jet cavity and guide cavity in the device adopt a trumpet-shaped or conical design. This structure can enhance the kinetic energy of the jet and increase the coupling effect between the jet and the ultrasonic wave. The jet plate adopts a circular design. The evenly distributed circular holes make the jet more uniform and stable, which helps to improve the processing effect.

[0061] Specifically, the aperture of the jet plate 5 is 1-5mm, including 1 and 5mm. The round holes are evenly distributed on the jet plate to generate jets and disperse sludge, thereby increasing the coupling effect with ultrasound.

[0062] Specifically, the multi-stage screening and conveying device 7 is connected to the sludge pump 8, which sends the sludge into the sand-water separation tank 9. The solid particles in the sludge are separated, and the filtered water after being treated by the screen 10 is used for water supply in the high-pressure water inlet pipe 3 or the low-speed water pipe 12.

[0063] Specifically, the jet plate 5 has evenly distributed circular holes.

[0064] Specifically, the jet plate 5 is circular.

[0065] Specifically, the initial input pressure in the high-pressure water inlet pipe 3 is 30-40 kPa, including 30 and 40 kPa. This pressure range is sufficient to generate a sufficient jet intensity, allowing the ultrasonic transducer 2 to operate at a frequency of 20-30 kHz, including 20 and 30 kHz, with a transmission cycle of 1.5-2 minutes, including 1.5 and 2 minutes. Within this cycle, a complete cycle of jet and ultrasonic action can be completed.

[0066] Specifically, the screen or filter mesh of the multi-stage screening and conveying device 7 has apertures of 10mm, 2mm, 0.1mm, and 0.075mm, respectively; the screen 10 or filter mesh of the sand-water separation tank 9 has apertures of 10mm, 2mm, 0.1mm, and 0.075mm, respectively; screens or filters with different apertures are used for different levels of screening, separating solid particles step by step from coarse to fine, ensuring that organic matter in the sludge is completely removed.

[0067] A multi-stage screening method for removing organic matter from sludge includes the following steps:

[0068] The sludge is initially separated by the jet. The sludge is then sent through a pipe to the area above the high-pressure water jet zone. The jet direction after the high-pressure water jet mixes with the sludge is set with a gradually expanding jet cavity 4. The high-pressure water jet passes through a jet plate before mixing with the sludge. The jet plate is evenly provided with holes with a diameter of 1-5mm, including 1 and 5mm.

[0069] After being guided, the separated sludge jet falls into the separation chamber, where it is ultrasonically cleaned and naturally sinks under gravity. During the sinking process, it is mixed with the rising water flow, causing the light organic components to float to the surface and flow out along the guide port.

[0070] Specifically, the settled sludge is screened by a multi-stage screening and conveying device 7 with different apertures and then sent to a sand-water separation tank 9. A screen 10 is installed in the sand-water separation tank 9, and the filtered water after being filtered by the screen 10 is used for jet or rising water flow.

[0071] Specifically, the jet cavity 4 is trumpet-shaped or cone-shaped.

[0072] Specifically, the sludge undergoes organic matter screening after pretreatment, which involves filtering out particles with a diameter greater than 5 mm.

[0073] Specifically, in one embodiment, the sludge from the drainage ditch, after being filtered by a coarse screen to remove domestic waste, is transported from the feed pipe 1 to the jet plate 5. Water is pressurized to 30 kPa and injected from the inlet of the high-pressure water inlet pipe 3. After passing through the circular jet plate 5 with a diameter of 2.5 mm, a high-pressure jet is formed, which creates a vacuum area in some areas. Between the scouring of the high-pressure jet and the collision between the sludge and the sludge, the organic flocs on the surface can be broken down and detached. The sludge after the initial screening is washed onto the guide hood by the high-pressure jet and falls into the water in the separation sedimentation tank under the action of gravity. The heavier sand and gravel sink, while the lighter organic components and the broken organic flocs float to the surface due to the rising water flow formed by the low-speed water flow injected into the inlet of the low-speed water pipe 12. The sludge is then discharged through the guide pipe 6, completing the initial screening of the organic components of the drainage ditch sludge.

[0074] As the heavier sand and gravel continue to sink after passing through the primary screening, ultrasonic transducers 2 are evenly distributed around the separation sedimentation chamber, emitting ultrasonic waves at a frequency of 20 kHz with an emission cycle of 1.5 min. Under the action of cavitation and oscillation, the organic flocs attached to the surface of the sand and gravel are further dispersed, emulsified, and peeled off. The sand and gravel and organic components complete the secondary screening. The sand and gravel continue to sink to the multi-stage screening device, while the organic flocs float to the surface under the action of the rising water flow and are discharged from the guide pipe 6.

[0075] The washed sand and gravel sink to the multi-stage screening and conveying device 7 under gravity. The multi-stage screening and conveying device 7 consists of surface screens and conveying devices. The screens have apertures of 10mm, 2mm, 0.1mm, and 0.075mm, which separate the sand and gravel into coarse stones larger than 10mm, coarse sand of 2-10mm, fine sand of 0.1-2mm, and micro-fine sand of 0.075-0.1mm, respectively. The sand and gravel are conveyed to the discharge port on the right side by their respective conveying devices and then pumped to the sand-water separation tank 9 by the sludge pump. The sand-water separation tank is equipped with screens 10 of corresponding apertures. The separated washing wastewater is filtered out and reused.

[0076] Specifically, in embodiment number two, the water pressure in the high-pressure inlet pipe 3 is increased to 35 kPa, and after passing through a circular jet plate with a diameter of 2.5 mm, a high-pressure jet with even greater pressure can be formed. At the same time, the ultrasonic transducer 2 emits ultrasonic waves at a frequency of 25 kHz. Compared with embodiment number one, by increasing the high-pressure inlet water pressure and the ultrasonic frequency, the organic components in the sand and gravel and the organic flocs on the surface of the sand and gravel can be removed more effectively. The organic loss on ignition in the sand and gravel in this embodiment is about 12.6%, which is 37.9% lower than the organic loss on ignition in the sand and gravel of embodiment number one (20.3%), and the removal effect is obvious.

[0077] Specifically, the difference between Embodiment 3 and Embodiment 1 is that the water pressure in the high-pressure inlet pipe 3 is increased to 40 kPa, forming a higher-pressure jet after passing through a circular jet plate with a diameter of 2.5 mm; simultaneously, the ultrasonic transducer 2 emits ultrasonic waves at a frequency of 30 kHz; compared with Embodiments 1 and 2, the high-pressure inlet water pressure and ultrasonic frequency are increased again. The organic loss on ignition in the sand and gravel in this embodiment is approximately 15.4%, which is 24.1% lower than the organic loss on ignition in Embodiment 1. This embodiment demonstrates that increasing the jet pressure and ultrasonic frequency can enhance the stripping of organic components, but excessively high water pressure and ultrasonic waves can inhibit the removal effect.

[0078] This invention addresses the challenges and pain points of incomplete washing of organic components and surface flocs in sludge from drainage ditches by coupling high-pressure jets and ultrasound. It also proposes a multi-stage screening and conveying device that integrates washing and screening, allowing for the full resource utilization of treated sand and gravel and reducing secondary pollution caused by indiscriminate landfilling.

[0079] In summary, this application features a device that utilizes jet and ultrasonic coupling technology to continuously clean ditch sludge and remove attached organic components. The device includes a separation sedimentation chamber, an inlet, and a feed pipe 1. High-pressure water flows into a jet plate 5 from the inlet. The jet plate 5 has micro-apertures to form a high-pressure jet. The feed pipe 1 is located outside the separation sedimentation chamber and connected to the jet plate 5. A guide cavity 11 is located at the top of the separation sedimentation chamber, through which the jetted ditch sludge falls into the water within the separation sedimentation chamber under the influence of gravity. Ultrasonic transducers 2 are arranged around the separation sedimentation chamber, with the lower transducer 2 corresponding to the inlet of a low-speed water pipe 12. The separation sedimentation chamber has an outlet.

[0080] The sludge of different particle sizes in the drainage ditch is screened out using a multi-stage screening and conveying device 7. The multi-stage screening and conveying device 7 includes a conveying device, a multi-layer screen composed of multiple screens, a sludge pump 8, and a sand-water separation tank 9.

[0081] The multi-stage screening method for removing organic matter from sludge comprises the following steps:

[0082] Step 1: The sludge from the drainage ditch, after being filtered by a coarse screen to remove large debris, is conveyed from the feed pipe 1 to the jet plate 5. High-pressure water flows in from the high-pressure water inlet pipe 3. The high-pressure jet formed on the jet plate 5 can create a partial vacuum, and the sludge from the drainage ditch is ejected with the jet, which can perform the initial screening of the organic components in the sludge. After the initial screening, the material is guided by the guide cavity 11 and enters the separation sedimentation tank water under the action of gravity. The organic components screened out in the initial screening are suspended in the water, while the heavier sand and gravel sink.

[0083] Step 2: Ultrasonic transducers 2 are evenly distributed around the separation sedimentation tank. Under the action of ultrasound, the organic flocs attached to the sinking sand and gravel are broken down and separated, completing the second screening. Low-speed water is injected into the separation sedimentation tank through the inlet of the low-speed water pipe 12 and flows out continuously from the water outlet 13, forming a continuous upward water flow. The lighter organic components and organic flocs from the primary and secondary screenings can be carried upward to the water surface with the upward water flow and discharged through the guide pipe 6 and the guide outlet.

[0084] Step 3: Under the influence of gravity, the washed sand and gravel sink to the multi-stage screening and conveying device 7. The multi-stage screening and conveying device 7 consists of screens with different apertures and a transmission device. Sand and gravel of different particle sizes fall onto the screens with corresponding apertures to complete multi-stage screening. The transmission device conveys the sand and gravel on the screens to the discharge port on the right side, and then transports it to the sand-water separation tank 9 through the sludge pump 8. The sand-water separation tank 9 is equipped with corresponding screens 10, and the washing wastewater is filtered out and reused.

[0085] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and substitutions can be made without departing from the technical principles of the present invention, and these improvements and substitutions should also be considered within the scope of protection of the present invention.

Claims

1. A multi-stage screening device for removing organic matter, characterized in that, The separation sedimentation chamber includes a feed pipe (1) and a high-pressure water inlet pipe (3) extending into it. A jet plate (5) is set at the intersection of the feed pipe (1) and the high-pressure water inlet pipe (3) so that the water in the high-pressure water inlet pipe (3) mixes with the material in the feed pipe (1) after passing through the jet plate (5) and is sprayed. A jet cavity (4) is set at the starting point of the jet to protect and guide the jet. A guide cavity (11) is set at the end of the jet direction to guide the jet into the ultrasonic cleaning zone of the separation sedimentation chamber. The ultrasonic cleaning zone includes an ultrasonic transducer (2) and the space surrounded by the side wall of the fixed ultrasonic transducer (2). A water outlet (13) of a low-speed water pipe (12) is provided below the ultrasonic cleaning zone. The water outlet (13) is used to form an upward water flow zone in the ultrasonic cleaning zone. At least two multi-stage screening and conveying devices (7) with different apertures are provided below the upward water flow zone to filter the separated and settled sludge. A guide port is provided at the water surface of the upward water flow zone. The guide port is connected to a guide pipe (6) to discharge the separated and floated organic matter. The jet plate is circular, and multiple circular holes with a diameter of 1–5 mm are evenly distributed on it; Both the jet cavity and the guide cavity are funnel-shaped or conical, used to guide the jet's spray path; The initial pressure input into the high-pressure water inlet pipe is 30–40 kPa; The frequency of the ultrasonic transducer is 20–30 kHz, and the emission period is 1.5–2 min. The multi-stage screening and conveying device includes at least four screens with apertures of 10mm, 2mm, 0.1mm and 0.075mm respectively. The filtered water in the sand-water separation tank is used to supply high-pressure water inlet pipes or low-speed water pipes to achieve the recycling of water resources.

2. The multi-stage screening device for removing organic matter as described in claim 1, characterized in that, The multi-stage screening and conveying device (7) is connected to the sludge pump (8). The sludge is sent to the sand-water separation tank (9) by the sludge pump (8). The filtered water after being treated by the screen (10) is used for water supply in the high-pressure water inlet pipe (3) or the low-speed water pipe (12).

3. The multi-stage screening device for removing organic matter as described in claim 1, characterized in that, The apertures distributed on the jet plate (5) include 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, and 5 mm.

4. The multi-stage screening device for removing organic matter as described in claim 1, characterized in that, The screens (10) of the sand-water separation tank (9) have apertures of 10 mm, 2 mm, 0.1 mm and 0.075 mm, respectively.

5. A multi-stage screening method for removing organic matter, used for screening organic matter in sludge, characterized in that, The multi-stage screening device for removing organic matter according to any one of claims 1-4 includes the following steps: The sludge is initially separated by the jet. The sludge is then sent through a pipe to the area above the high-pressure water jet zone. The jet direction after the high-pressure water jet mixes with the sludge is set with a gradually expanding jet cavity (4). The high-pressure water jet passes through a jet plate before mixing with the sludge. Holes are evenly arranged on the jet plate with a diameter of 1-5mm, including 1 and 5mm. After being guided, the separated sludge jet falls into the separation chamber, is ultrasonically cleaned, and sinks naturally under gravity. During the sinking process, it is mixed with the rising water flow, which causes the light organic components to float to the surface and flow out along the guide port. The sludge that sinks is screened by a multi-stage screening and conveying device (7) with different apertures and then sent to a sand-water separation tank (9). A screen (10) is installed in the sand-water separation tank (9). The filtered water after being filtered by the screen (10) is used for jet or rising water flow. After pretreatment, the sludge undergoes organic matter screening, with the pretreatment process removing particles larger than 5 mm in diameter.

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