A municipal wastewater pretreatment system and treatment method

Abstract

This invention provides a municipal wastewater pretreatment system and method, belonging to the field of municipal wastewater treatment technology. It includes a primary filtration tank, a secondary filtration tank, and a vortex grit chamber arranged sequentially. The primary and secondary filtration tanks are respectively equipped with coarse and fine screen filters. Municipal wastewater sequentially passes through the primary and secondary filtration tanks and enters the vortex grit chamber. The vortex grit chamber includes an upper grit hopper, a lower grit hopper, a stirring mechanism within the grit hopper, and a grit removal mechanism extending into the grit hopper. The stirring mechanism includes an electrically driven stirring shaft and a retractable stirring impeller mounted on the stirring shaft. A magnetic powder feeding channel is provided at the grit hopper, and an electromagnetic coil is installed on the side wall of the grit hopper. This invention improves the stirring effect on wastewater, facilitates blade maintenance, and prevents the compaction of sand and gravel in the wastewater within the vortex grit chamber, making it easier to discharge the sand and gravel.

Description

Technical Field

[0001] This invention belongs to the field of municipal wastewater treatment technology, specifically relating to a municipal wastewater pretreatment system and treatment method. Background Technology

[0002] Currently, in the process of municipal sewage treatment, the sewage must first undergo pretreatment to filter out larger impurities such as sand and gravel, so that it can be processed in the next step. In the pretreatment process, larger impurities in the sewage are usually filtered through screens of different sizes (coarse screens and fine screens) before being poured into a grit chamber for particle filtration.

[0003] A vortex grit chamber is a common type of grit chamber. It uses mechanical force to control the flow pattern and velocity of water, causing sand particles in the wastewater to settle in a spiral pattern along the chamber wall under the action of centrifugal force and gravity, thus achieving the purpose of sand particle settling. Wastewater flows into the grit hopper of the vortex grit chamber tangentially through the inlet. The agitator set in the grit hopper rotates, causing the wastewater to form a vortex state. Under the action of centrifugal force, the sand particles in the wastewater are thrown towards the chamber wall and slide down the chamber wall into the grit hopper at the bottom. The substances attached to the surface of the sand particles enter the next treatment equipment along with the wastewater. The collected sand particles are discharged through the sand lifting mechanism.

[0004] However, in existing vortex grit chambers, the grit in the hoppers tends to be compacted during long-term sedimentation, making it difficult to discharge and causing blockages inside the hoppers. When the agitator is running, the agitation process can only be controlled by adjusting the agitation speed, which is a single adjustment factor. Furthermore, the agitator blades are prone to wear at their ends after long-term use, requiring the replacement of the entire blade, which increases maintenance costs. Summary of the Invention

[0005] In view of the above-mentioned problems existing in the prior art, the purpose of the present invention is to provide a municipal sewage pretreatment system and treatment method.

[0006] This invention provides the following technical solution: a municipal sewage pretreatment system, comprising a primary filtration tank, a secondary filtration tank, and a vortex grit chamber arranged sequentially; the primary and secondary filtration tanks are respectively equipped with a coarse screen filter and a fine screen filter; municipal sewage enters the vortex grit chamber sequentially through the primary and secondary filtration tanks; the vortex grit chamber includes an upper grit hopper, a lower grit hopper, a stirring mechanism disposed in the grit hopper, and a grit lifting mechanism extending into the grit hopper; the stirring mechanism includes an electrically driven stirring shaft and a retractable stirring impeller disposed on the stirring shaft; a magnetic powder feeding channel is provided at the grit hopper, and an electromagnetic coil is disposed on the side wall of the grit hopper.

[0007] Furthermore, the wastewater filtered by the primary filtration tank is introduced into the secondary filtration tank via the lift tank, and the wastewater filtered by the secondary filtration tank enters the vortex grit chamber through the pipeline.

[0008] Furthermore, the retractable stirring impeller includes a set of retractable blades, each blade consisting of a blade body and an extension blade. The blade body is inserted into the extension blade and connected by a set of springs.

[0009] Furthermore, the blade body and the extended blade are positioned by a matching structure of positioning protrusions and positioning grooves.

[0010] Furthermore, the extended blade has a through hole for installing a spring, and a plug is provided at the through hole.

[0011] Furthermore, the magnetic powder feeding channel is located at the inlet of the grit chamber to mix the magnetic powder with the flowing sewage.

[0012] Furthermore, the sidewall of the sand hopper is a hollow structure, and the electromagnetic coil is wound inside the hollow structure and located at the bottom of the hollow structure.

[0013] Furthermore, the sand hopper is equipped with a float ball, which has a mesh-like hollow shell structure.

[0014] Furthermore, the outlet of the cyclone sedimentation tank is connected to a magnetic separator via a pipeline, and the outlet of the magnetic separator is connected to the next process system.

[0015] A method for treating municipal wastewater pretreatment systems includes the following steps:

[0016] S1. Municipal sewage is introduced into the primary filtration tank through pipelines, and impurities in the sewage are filtered through a coarse screen filtration device.

[0017] S2. Wastewater that has passed through the primary filtration enters the lifting tank and is then lifted to the secondary filtration tank by a lifting pump, where it undergoes secondary filtration through a fine screen filter.

[0018] S3. After secondary filtration, the wastewater is introduced into the vortex grit chamber through pipes and water pumps. The wastewater is mixed with the magnetic powder poured in at the inlet of the grit hopper in the vortex grit chamber and enters the grit hopper. The stirring mechanism is turned on to form a vortex to stir the wastewater. During the rotation of the stirring shaft, the extension blades in the telescopic blades extend outward under the action of centrifugal force as the stirring speed changes. When the stirring speed is kept constant, the extension blades maintain the corresponding extension length.

[0019] S4. After passing through the settling hopper, the sand and gravel in the sewage enter the sand hopper for sedimentation. The sand lifting mechanism then operates to discharge the sand and gravel.

[0020] S5. After the cyclone sedimentation tank has been running for the set time, the electromagnetic coil is energized, causing the magnetic powder in the sand hopper to vibrate, which in turn causes the sand and gravel with magnetic powder to vibrate synchronously, preventing the sand and gravel from being compacted at the bottom of the sand hopper.

[0021] By employing the above-described technology, the beneficial effects of the present invention compared to the prior art are as follows:

[0022] 1) In this invention, the stirring blade adopts a retractable split structure design, which can extend its length accordingly with the change of stirring speed. While adjusting the stirring speed, the stirring radius can be adjusted accordingly to improve the stirring effect on sewage. Moreover, the split structure design allows for better replacement of easily worn ends, reducing waste of blade material.

[0023] 2) In this invention, by mixing magnetic powder with sewage, the magnetic powder can adhere to the sand and gravel particles in the sewage during the stirring process, so that there is a certain repulsive force between the sand and gravel that slides into the sand hopper, reducing the occurrence of sand compaction; and by setting up an electromagnetic coil, the magnetic powder is vibrated after being energized, which further prevents the sand particles in the sewage from being compacted in the sand hopper.

[0024] 3) In this invention, the design of the positioning and insertion structure between the blade body and the extended blade can achieve the adjustment of the blade stirring radius while ensuring the overall strength; and different adjustment effects can be obtained simply by replacing the springs with different elastic coefficients to meet the needs of different working conditions.

[0025] 4) In this invention, a certain number of floats can be set in the sand hopper to avoid sand compaction by the collision between the floats and the sand particles; the floats adopt a grid-type spherical structure design, which allows water to flow smoothly through the floats and minimizes the generation of turbulence. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the overall system of the present invention;

[0027] Figure 2 This is a schematic diagram of the vortex grit chamber of the present invention;

[0028] Figure 3 This is a partial structural schematic diagram of the retractable blade of the present invention;

[0029] Figure 4 This is a schematic diagram of the internal structure of the retractable blade of the present invention;

[0030] Figure 5 This is a schematic diagram of another form of the retractable blade of the present invention;

[0031] Figure 6 This is a schematic diagram of the structure of the float of the present invention. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0033] Conversely, this invention encompasses any substitutions, modifications, equivalent methods, and solutions made within the spirit and scope of the invention as defined in the claims. Furthermore, to provide a better understanding of the invention, certain specific details are described in detail below. However, those skilled in the art will fully understand the invention even without these detailed descriptions. Example

[0034] like Figure 1 As shown, this embodiment provides a municipal sewage pretreatment system, which includes a primary filter tank 1, a secondary filter tank 2, a cyclone grit chamber 3, and a magnetic separator 10 arranged in sequence.

[0035] Specifically, a coarse screen filter 101 is installed in the primary filtration tank 1 to filter larger particles and suspended solids in the wastewater; the wastewater filtered by the coarse screen flows into the lift tank 8 and is then pumped into the secondary filtration tank 2.

[0036] Specifically, a fine screen filter device 201 is installed in the secondary filter tank 2 to filter smaller particles and suspended solids; the wastewater filtered by the fine screen is introduced into the vortex grit chamber 3 through pipes and water pumps.

[0037] Specifically, such as Figure 2 As shown, the vortex grit chamber 3 includes an upper grit hopper A and a lower grit hopper B, and the two structures are connected.

[0038] The top of the vortex grit chamber 3 is equipped with a cover plate and a support for easy climbing; the cover plate is equipped with a mixing mechanism 4 and a sand lifting mechanism 5.

[0039] The stirring mechanism 4 includes a motor 406, the output shaft of which is connected to a stirring shaft 401. The lower end of the stirring shaft 401 extends into the sediment hopper A and is fixedly mounted with a retractable stirring impeller. The retractable stirring impeller includes four retractable blades, such as... Figure 3-5The retractable blade includes a blade body 402 and an extension blade 403. In this embodiment, the extension blade 403 has a slot, the blade body 402 is inserted into the slot and connected by two springs 404. The slot has a positioning groove, and the blade body 402 has positioning protrusions on both sides. The blade body 402 and the extension blade 403 are positioned by the matching structure between the positioning groove and the positioning protrusion. A through hole is opened on the extension blade at the position where the spring is connected, so that one end of the spring can be fixed in the slot. A plug 405 is fixedly installed at the through hole by a threaded engagement structure.

[0040] Alternatively, a structural design can be adopted in which the extended blade 403 is inserted into the blade body 402. The structure of the extended blade 403 and the blade body 402 is designed according to actual needs, and the above design is also within the scope of the embodiments of the present invention.

[0041] The sand lifting mechanism 5 is the same as the existing sand lifting structure, with its lower section extending into the sand hopper B and its sand discharge outlet connected to an external sand discharge pipe.

[0042] Specifically, a magnetic powder feeding channel 6 is set at the inlet of the settling hopper A to put magnetic powder into the settling hopper A and mix it with sewage. The magnetic powder can be filled manually or connected to an external magnetic powder supply device through a pipeline.

[0043] The side wall of sand hopper B is hollow, and an electromagnetic coil 7 is wound around the lower part of the hollow structure. When energized, it forms a magnetic field that vibrates the magnetic powder attached to the particles, thus preventing the particles from being compacted in sand hopper B.

[0044] The wastewater outlet of the cyclone grit chamber 3 is connected to the magnetic separator 10 through a pipeline to separate and recycle the magnetic powder in the wastewater for reuse. The wastewater after passing through the magnetic separator 10 enters the next process system.

[0045] Specifically, floats 9 can be placed in sand hopper B. The collision between the floats and the particles prevents particle compaction. Based on the need for stable swirling flow in sand hopper B, the volume and number of floats 9 are controlled to avoid affecting the stable swirling flow. The floats are also designed with a mesh-like perforated shell structure (in this embodiment, a honeycomb mesh is used, such as...). Figure 6 As shown in the figure, this allows the swirling flow to pass smoothly through the float, minimizing the generation of turbulence.

[0046] The wastewater pretreatment method based on the system in this embodiment is as follows:

[0047] S1. Municipal sewage is introduced into the primary filtration tank 1 through a pipeline, and the sewage is filtered through the coarse screen 101 to remove impurities and intercept larger particles and suspended solids in the sewage.

[0048] S2. Wastewater that has passed through the primary filter enters the lifting tank 8 and is pumped into the secondary filter tank 2 by the lifting pump. It undergoes secondary filtration through the fine screen 102 to further remove smaller suspended solids, thereby reducing wear on subsequent equipment and pipelines.

[0049] S3. After secondary filtration, the wastewater is introduced into the vortex grit chamber 3 through pipes and water pumps. The wastewater is mixed with the magnetic powder poured in at the inlet of the grit chamber A in the vortex grit chamber 3 and enters the grit chamber A. The stirring mechanism is turned on to stir the wastewater and form a vortex. During the rotation of the stirring shaft, the extension blades 403 in the telescopic blades extend outward under the action of centrifugal force as the stirring speed changes. When the stirring speed is kept constant, the extension blades 403 maintain the corresponding extension length.

[0050] S4. Under the action of centrifugal force and gravity, the sand and gravel in the sewage slide down through the sedimentation zone A to the sand hopper B. The sand lifting mechanism 5 is activated (the sand lifting mechanism 5 is the same as the sand lifting device in a conventional vortex sedimentation tank, and its structure and working principle will not be described in this embodiment) to discharge the sand and gravel.

[0051] S5, after the vortex sedimentation tank 3 has been running for the set time, the electromagnetic coil 7 is energized (alternating current), causing the magnetic powder in the sand hopper B to vibrate under the action of the magnetic field gradient, which in turn causes the sand and gravel with magnetic powder to vibrate synchronously, preventing the sand and gravel from being compacted at the bottom of the sand hopper B.

[0052] S5, the effluent from the cyclone grit chamber 3 is introduced into the magnetic separator 10 to recover the magnetic powder in the effluent; the effluent from the magnetic separator 10 flows into the subsequent anoxic MBR tank and other treatment systems for further treatment.

[0053] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A municipal wastewater pretreatment system, characterized by, The utility model relates to a municipal sewage treatment device, including the sequentially arranged first filter tank (1), second filter tank (2) and cyclone grit chamber (3), the first filter tank (1), second filter tank (2) in respectively be provided with coarse grid filter device (101), fine grid filter device (201), municipal sewage sequentially via first filter tank (1), second filter tank (2) into cyclone grit chamber (3) in, the cyclone grit chamber (3) includes the grit chamber (A) of upper portion, the grit chamber (B) of lower portion, is set up in grit chamber (A) stirring mechanism (4) and reaches sand mechanism (5) of sand grit chamber (B) in, the stirring mechanism (4) includes electric drive's stirring shaft (401) and is set up in the retractable stirring vane of stirring shaft (401), the grit chamber (A) at is provided with magnetic powder feeding channel (6), and the sidewall of grit chamber (B) is provided with electromagnetic coil (7), The sand chamber (B) is provided with a floating ball (9), which is a grid-shaped hollow shell structure.

2. A municipal wastewater pretreatment system according to claim 1, wherein The wastewater filtered by the first filter tank (1) is introduced into the second filter tank (2) through the lifting tank (8), and the wastewater filtered by the second filter tank (2) is introduced into the cyclone grit chamber (3) through the pipeline.

3. The municipal wastewater pretreatment system of claim 1, wherein, The retractable stirring vane includes a set of retractable blades, and the retractable blades include a blade body (402) and an extension blade (403). The blade body (402) is inserted into the extension blade (403) and connected by a set of springs (404).

4. A municipal wastewater pretreatment system according to claim 3, wherein The blade body (402) and the extension blade (403) are positioned by the cooperation of the positioning protrusions and the positioning grooves.

5. A municipal wastewater pretreatment system according to claim 3, wherein A through hole is formed on the extension blade (403) for mounting the spring, and a plug (405) is arranged at the through hole.

6. A municipal wastewater pretreatment system according to claim 1, wherein The magnetic powder feeding channel (6) is arranged at the inlet of the grit chamber (A) to mix the magnetic powder with the inflowing wastewater.

7. A municipal wastewater pretreatment system according to claim 6, wherein The sidewall of the grit chamber (B) is a hollow structure, and the electromagnetic coil (7) is wound in the hollow structure and located at the lower part of the hollow structure.

8. A municipal wastewater pretreatment system according to claim 1, wherein The outlet of the cyclone grit chamber (3) is connected with a magnetic separation machine (10) through a pipeline, and the outlet of the magnetic separation machine (10) is connected with a next process system.

9. The method of claim 3-8, wherein the municipal wastewater pretreatment system is characterized by, The utility model relates to a municipal sewage treatment device, including the sequentially arranged first filter tank (1), second filter tank (2) and cyclone grit chamber (3), the first filter tank (1), second filter tank (2) in respectively be provided with coarse grid filter device (101), fine grid filter device (201), municipal sewage sequentially via first filter tank (1), second filter tank (2) into cyclone grit chamber (3) in, the cyclone grit chamber (3) includes the grit chamber (A) of upper portion, the grit chamber (B) of lower portion, is set up in grit chamber (A) stirring mechanism (4) and reaches sand mechanism (5) of sand grit chamber (B) in, the stirring mechanism (4) includes electric drive's stirring shaft (401) and is set up in the retractable stirring vane of stirring shaft (401), the grit chamber (A) at is provided with magnetic powder feeding channel (6), and the sidewall of grit chamber (B) is provided with electromagnetic coil (7), The sand chamber (B) is provided with a floating ball (9), which is a grid-shaped hollow shell structure. S1, municipal sewage is introduced into the first filter tank (1) through the pipeline, and the sundries of wastewater are filtered by the coarse grid filter device (101) in the first stage; S2, the wastewater filtered in the first stage is introduced into the lifting tank (8), lifted into the second filter tank (2) by the lifting pump, and filtered in the second stage by the fine grid filter device (201); S3, the wastewater filtered in the second stage is introduced into the cyclone grit chamber (3) through the pipeline and the water pump, mixed with the magnetic powder at the inlet of the grit chamber (A) in the cyclone grit chamber (3), introduced into the grit chamber (A), and the stirring mechanism is started to form the cyclone to stir the wastewater. During the rotation of the stirring shaft, the extension blade (403) in the retractable blade extends outward under the action of the centrifugal force, and maintains the corresponding extension length when the stirring speed remains uniform. S4, the sand in the sewage after the sand trap (A) into the sand trap (B) for sedimentation, sand mechanism (5) action, the sand is discharged; S5, when the cyclone grit chamber runs for a set time, the electromagnetic coil (7) is energized, so that the sand trap (B) in the magnetic powder vibration, and then make the sand with magnetic powder synchronous vibration, to avoid the sand in the bottom of sand trap (B) compaction.

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