CN111617520B

CN111617520B - Turbulent flow sedimentation tank

Info

Publication number: CN111617520B
Application number: CN202010397174.1A
Authority: CN
Inventors: 尚铁军
Original assignee: Dalian Radlant Water Treatment Technology Co ltd
Current assignee: DALIAN RADLANT WATER TREATMENT TECHNOLOGY CO.,LTD.
Priority date: 2020-05-12
Filing date: 2020-05-12
Publication date: 2021-11-30
Anticipated expiration: 2040-05-12
Also published as: CN111617520A

Abstract

The invention relates to a turbulent sedimentation tank, which uses a Venturi inner component to assist particle impurities in water flow to coagulate and grow, and then introduces the grown particles into a sludge channel at the outer side at the tail end of a Venturi tube by means of a rotational flow ring and discharges the particles into a sludge collecting pipe; in the process, the treatment and the flow of raw water and the sedimentation and the drainage of particles respectively occur in two relatively independent spaces of a Venturi tube and a sludge channel, and no interference exists between the two spaces; the flow state in the inner member is not limited by laminar flow and is mainly in a strong turbulent flow state, so that the water treatment flow is large; the strong turbulent flow state is not beneficial to the generation and the attachment of a biological membrane, and the running state of the equipment can be kept stable for a long time; through the cooperative configuration of the swirl ring and the inscribed direction of the through hole at the throat, most of particulate matters, especially large particulate matters, entering the sludge channel can actively avoid the through hole, or slide from the surface of the through hole by means of swirl inertia, so that the particulate matters can be prevented from entering the throat again along with water flow through the through hole; the fine particles with the particle size not growing up are allowed to enter the throat again to participate in a new coagulation and growth process; meanwhile, the through hole at the throat is not easy to be blocked, and the operation maintenance period of the equipment is prolonged.

Description

Turbulent flow sedimentation tank

Technical Field

The invention relates to sewage treatment equipment, in particular to a turbulent flow sedimentation tank.

Background

Sedimentation treatment is an important link of a sewage treatment process, and compared with filtration treatment, the sedimentation treatment has the obvious advantages of large treatment capacity, low cost, no blockage problem, continuous operation and the like in the aspect of removing particles in water; therefore, the method is widely applied in the field of sewage treatment. In the prior art, to improve the precipitation efficiency of a precipitation tank, internal components such as an inclined plate or an inclined pipe are generally arranged in the precipitation tank by utilizing a shallow layer precipitation theory so as to shorten the precipitation distance of particulate matters. However, such internals, while reducing the settling distance of the particles, are highly susceptible to turbulence in the fluid within or between the tubes and plates, resulting in a reduction in the settling efficiency of the particles, and thus limiting the fluid flow rate to a smaller range; it is generally required that the liquid flow be in a laminar state within the tubes or plates to prevent turbulence to the particles. While the laminar flow state is substantially beneficial to the formation of flocculent biological membranes, although the biological membranes are widely used for removing organic pollutants in water treatment, the biological membranes appearing in the flow channels of the inclined pipes or the inclined plates can greatly reduce the flow space in the pipes and seriously hinder the sedimentation and the transfer of particles to the bottom of the pool. In addition, because the inclined pipe or the inclined plate inner member generally has a smaller flow passage size, the flow passage is often blocked in practical use, so that frequent shutdown and renovation are caused; in addition, impurities blocked in the narrow channel are not easy to remove in the cleaning process, and even the inner components of the assembled inclined tube or inclined plate need to be disassembled and cleaned. This greatly hinders the practical value of such internals.

Disclosure of Invention

In order to overcome the problems in the prior art, the invention provides the turbulent sedimentation tank which allows the sedimentation separation of the particulate matters to be carried out in a high-flow-rate turbulent state, has larger unit volume treatment capacity compared with the traditional sedimentation mode, and is beneficial to realizing the miniaturization of the sedimentation tank; meanwhile, the turbulent sedimentation tank can be automatically cleaned in the operation process, the blockage phenomenon cannot occur, and the long-term continuous operation of the sedimentation tank is facilitated.

In order to achieve the above purpose, the present invention specifically provides the following scheme:

a turbulent sedimentation tank comprises a tank body 1, wherein a vertical partition plate 4 is arranged inside the tank body 1, and the partition plate 4 divides the inside of the tank body 1 into a water inlet cavity 3 and a sedimentation cavity 7; a water inlet unit is arranged on the side wall of the water inlet cavity 3; the bottom of the partition plate 4 is provided with a plurality of water diversion ports 5 which are arranged at intervals; the bottom in the sedimentation cavity 7 is provided with distribution channels 28 the number of which is the same as that of the water inlets 5; the distribution channels 28 are arranged in parallel with each other, and one end of each distribution channel is connected to the water inlet 5 in a fluid-tight manner and is used for receiving raw water from the water inlet chamber 3 from the water inlet 5; a mud collecting groove 27 is formed between the adjacent distribution channels 28; a closing plate 8 is arranged in the sedimentation cavity 7 and positioned above the top end of the water diversion port 5 to divide the sedimentation cavity 7 into a clear water area positioned at the upper part of the closing plate 8 and a sludge area positioned at the lower part of the closing plate 8; the sealing plate 8 is provided with a plurality of mounting holes 9 which are arranged in an array; each of the mounting holes 9 is located above the top of the distribution channel 28; a venturi inner component 10 is arranged at one side of each mounting hole 9 above the closing plate 8; the venturi inner 10 can receive raw water from the distribution passage 28, promote the fine particles in the water to agglomerate and grow, and then discharge the grown particles into the sludge collection groove 27.

The vertical dimension (which can be understood as height) of the distribution channel 28 in the length direction thereof is gradually reduced to offset the pressure drop upstream and downstream in the distribution channel 28 caused by the flow division of the raw water into the plurality of venturi inner members 10 when the raw water flows along the length direction thereof; thereby allowing the raw water to maintain substantially the same pressure when entering the inlets of the venturi inner 10 at different positions.

The upper surface of the distribution channel 28 is provided with a plurality of connecting pipes 29 correspondingly connected with the inlets of the venturi inner member 10; the connecting tube 29 has a varying height along the length of the distribution channel 28 to match the vertical dimension variation of the distribution channel 28 in the length direction.

The mounting hole 9 and the connecting pipe 29 are concentrically arranged, and the diameter of the mounting hole 9 is larger than that of the connecting pipe 29, so that a sludge discharge annular gap is formed between the mounting hole 9 and the connecting pipe 29, and the venturi inner member 10 is allowed to discharge sludge into a sludge area through the sludge discharge annular gap.

The water inlet unit comprises a water inlet hole 2 arranged on the side wall of the water inlet cavity 3 and an overflow groove 6 positioned at the downstream of the water inlet hole 2.

The venturi inner 10 comprises a housing and a venturi tube 14 located within the housing; the outer shell comprises a lower shell tube 11 with a larger diameter positioned at the lower part, an upper shell tube 12 with a smaller diameter positioned at the upper part and a truncated cone-shaped connecting shell 13 connecting the lower shell tube 11 and the upper shell tube 12; the venturi tube 14 is located in the space formed by the lower shell tube 11 and the connecting shell 13, and the end of the diffuser tube at the top thereof is connected to the lower end of the upper shell tube 12 through a swirl ring 15; the Venturi tube 14, the lower shell tube 11, the upper shell tube 13, the connecting shell 13 and the swirl ring 15 are concentrically arranged; the venturi tube 14 has a throat 16 and a water inlet 18 at the bottom for inflow of raw water; an annular sludge channel 17 is formed between the outer wall of the Venturi tube 14 and the inner wall of the lower shell tube 11.

The bottom opening of the sludge channel 17 is connected to the sludge discharge annulus, and the width of the bottom opening is not smaller than the sludge discharge annulus.

The side wall of the rotational flow ring 15 is provided with internally tangent (tangent with the inner annular wall) screwing openings 25 which are uniformly distributed along the circumference; preferably, the screwing-on opening 25 is long-strip-shaped; which allows a flow of water having a higher pressure and agglomerated growing particles to flow to the end of the diffuser of the venturi tube 14 and to swirl into the annular sludge channel 17, which is depressurized by the ejector effect at the throat 16.

The throat 16 of the venturi tube 14 is provided with through holes 26 in an array shape uniformly distributed along the circumferential wall; the through hole 26 and the start-up rotary opening 25 are arranged in the same inscribing direction; therefore, when the muddy water containing sludge particles entering the sludge channel 17 through the swirling mouth 25 reaches the throat 16, most of the particles are thrown to the outer side wall of the sludge channel 17 due to centrifugal force, and part of the particles still flowing against the outer side wall of the throat 16 slide through the outer side of the through hole 26 due to the same swirling direction as the inner contact direction of the through hole 26, and the swirling inertia of the particles separates most of the particles flowing through the through hole 26 from the water body where the particles are located, so that the water flow enters the throat from the through hole 26 due to the suction effect of the throat 16, and the particles slide through the outer side of the through hole 26 under the rotation inertia effect of the particles. The larger the size of the particles is, the more obvious the effect of the separation effect is, and part of the particles with smaller sizes may enter the throat 16 again due to the washing of the water flow, but the part of the particles with smaller sizes may participate in the processes of collision and growth between the particles in the throat 16 again, and finally become large particles to be separated. In order to ensure the separation effect of the particles and the water body, the water flow entering the clear water area can partially flow back to the water inlet cavity 3 or the original water area to participate in the coagulation, growth and separation processes of the particles again so as to further reduce the content of the particles in the water flow.

The bottom of each mounting hole 9 is connected with two opposite mud discharging slideways 19; the two opposite sludge discharge chutes 19 respectively extend into the sludge grooves 27 on two sides of the distribution channel 28 corresponding to the mounting holes 9 so as to avoid the deposition of sludge on the upper surface of the distribution channel 28. The deposition of sludge on the upper surface of the distribution channel 28 may affect the actual sludge discharge flux of the sludge discharge annulus, e.g. when the sludge deposition height is too great, it may extend partly not far below the sludge discharge annulus, even through the sludge discharge annulus to the interior of the sludge channel 17, thereby blocking the effective discharge path of the sludge. This phenomenon is more serious particularly on the upstream side of the distribution channel 28.

The mud discharging slideway 19 has an arched tile-shaped structure and comprises an outer arch plate 20 and an inner arch plate 21 which are arranged in parallel and arched outwards, and two side plates 22 for connecting the side edges of the inner arch plate and the outer arch plate; the inner arch plate 20, the outer arch plate 21 and the two side plates 22 enclose a sandwich channel of the mud discharge slideway 19; the interlayer channel is provided with an inlet 23 which is positioned at the upper end of the mud discharging slideway 19 and is used for being communicated with the mud channel 17 of the Venturi inner member 10, and an outlet 24 which is positioned at the lower end of the mud discharging slideway 19 and extends into the mud collecting groove 27; the inlets 23 of the two sludge discharge chutes 19 which are opposite to each other are combined to form a complete circular inlet which just covers the sludge channel 17; the two side plates 22 on the same side of the two opposite sludge discharge chutes 19 are gradually far from top to bottom, so that the outlets 24 of the two opposite sludge discharge chutes 19 cannot form a complete circle, so as to allow the bottoms of the two opposite sludge discharge chutes 19 to extend across the distribution channel 28 and the connecting pipe 29 into the sludge grooves 27 on both sides of the distribution channel 28.

Sludge discharging components can be arranged in the sludge groove 27 and the distribution channel 28, and the sludge discharging components can be sludge discharging ports which are arranged on the side walls of the plurality of the cell bodies 1 and correspond to one ends of the sludge groove 27 and the distribution channel 28, which are far away from the partition plate 4, and/or sludge conveying devices arranged in the sludge groove 27 and the distribution channel 28.

The sludge conveying device can be a scraper, a sludge suction pipe, a semi-open auger and the like.

Compared with the prior art, the invention can at least obtain the following beneficial effects: the invention adopts the jet mixing action of the venturi inner member with the sandwich structure to promote the coagulation and growth of particles in water flow, and then introduces the grown particles into the sludge channel at the outer side at the tail end of the venturi tube by means of the rotational flow ring and discharges the particles into the sludge collecting pipe; in the process, the treatment and the flow of raw water and the sedimentation and the drainage of particles respectively occur in two relatively independent spaces in a Venturi tube and a sludge channel, and no interference exists between the two spaces; the flow state in the inner member is not limited by laminar flow and is mainly in a strong turbulent flow state, so that the water treatment flow is large; the strong turbulent flow state is not beneficial to the generation and the attachment of a biological membrane, and the running state of the equipment can be kept stable for a long time; through the cooperative configuration of the swirl ring and the inscribed direction of the through hole at the throat, most of particulate matters, especially large particulate matters, entering the sludge channel can actively avoid the through hole, or slide from the surface of the through hole by means of swirl inertia, so that the particulate matters can be prevented from entering the throat again along with water flow through the through hole; the fine particles with the particle size not growing up are allowed to enter the throat again to participate in a new coagulation and growth process; meanwhile, the through hole at the throat is not easy to be blocked, and the operation maintenance period of the equipment is prolonged.

Drawings

FIG. 1 is a schematic view of the structure of a sedimentation tank according to the present invention;

FIG. 2 is a schematic longitudinal cross-sectional view of a venturi inner member of the present invention;

FIG. 3 is a schematic sectional view of a settling tank according to the present invention (without a sludge discharge chute);

FIG. 4 is a schematic view of a swirl ring of the present invention;

FIG. 5 is a schematic cross-sectional view of a throat according to the present invention;

FIG. 6 is a schematic view of the structure of the opposed mud discharge chute assembly of the present invention.

In the figure: 1 is the cell body, 2 is the inlet opening, 3 is the intake antrum, 4 is the baffle, 5 is the inlet scoop, 6 is the overflow launder, 7 is the sedimentation chamber, 8 is the closing plate, 9 is the mounting hole, 10 is the venturi internals, 11 is the lower casing pipe, 12 is the upper casing pipe, 13 is the connecting shell, 14 is venturi, 15 is the whirl ring, 16 is the choke, 17 is the mud passageway, 18 is the water inlet, 19 is the slide of unloading mud, 20 is outer arch bar, 21 is inner arch bar, 22 is the curb plate, 23 is the entry, 24 is the export, 25 is the start turn round, 26 is the through-hole, 27 is the mud groove, 28 is the distribution passageway.

Detailed Description

To better illustrate the concept of the present invention, preferred embodiments of the present invention will be described below with reference to the accompanying drawings.

Referring to fig. 1, a turbulent sedimentation tank is provided, which comprises a tank body 1, wherein a vertical partition plate 4 is arranged inside the tank body 1, and the partition plate 4 divides the inside of the tank body 1 into a water inlet cavity 3 and a sedimentation cavity 7; a water inlet unit is arranged on the side wall of the water inlet cavity 3; the bottom of the partition plate 4 is provided with a plurality of water diversion ports 5 which are arranged at intervals; the bottom in the sedimentation cavity 7 is provided with distribution channels 28 the number of which is the same as that of the water inlets 5; the distribution channels 28 are arranged in parallel with each other, and one end of each distribution channel is connected to the water inlet 5 in a fluid-tight manner and is used for receiving raw water from the water inlet chamber 3 from the water inlet 5; a mud collecting groove 27 is formed between the adjacent distribution channels 28; a closing plate 8 is arranged in the sedimentation cavity 7 and positioned above the top end of the water diversion port 5 to divide the sedimentation cavity 7 into a clear water area positioned at the upper part of the closing plate 8 and a sludge area positioned at the lower part of the closing plate 8; the sealing plate 8 is provided with a plurality of mounting holes 9 which are arranged in an array; each of the mounting holes 9 is located above the top of the distribution channel 28; a venturi inner component 10 is arranged at one side of each mounting hole 9 above the closing plate 8; the venturi inner 10 can receive raw water from the distribution passage 28, promote the fine particles in the water to agglomerate and grow, and then discharge the grown particles into the sludge collection groove 27.

Referring to fig. 1 and 3, the vertical dimension of the distribution channel 28 along its length decreases. The upper surface of the distribution channel 28 is provided with a plurality of connecting pipes 29 correspondingly connected with the inlets of the venturi inner member 10; the connecting tube 29 has a varying height along the length of the distribution channel 28.

Referring to fig. 1 and 3, the mounting hole 9 is concentrically arranged with the connecting pipe 29, and the diameter of the mounting hole 9 is larger than that of the connecting pipe 29, so that a sludge discharge annular space is formed therebetween.

Referring to fig. 1, the water inlet unit includes a water inlet hole 2 provided on a sidewall of the water inlet chamber 3 and an overflow launder 6 located downstream of the water inlet hole 2.

Referring to FIG. 2, the venturi inner 10 includes a housing and a venturi 14 located within the housing; the outer shell comprises a lower shell tube 11 with a larger diameter positioned at the lower part, an upper shell tube 12 with a smaller diameter positioned at the upper part and a truncated cone-shaped connecting shell 13 connecting the lower shell tube 11 and the upper shell tube 12; the venturi tube 14 is located in the space formed by the lower shell tube 11 and the connecting shell 13, and the end of the diffuser tube at the top thereof is connected to the lower end of the upper shell tube 12 through a swirl ring 15; the Venturi tube 14, the lower shell tube 11, the upper shell tube 13, the connecting shell 13 and the swirl ring 15 are concentrically arranged; the venturi tube 14 has a throat 16 and a water inlet 18 at the bottom for inflow of raw water; an annular sludge channel 17 is formed between the outer wall of the Venturi tube 14 and the inner wall of the lower shell tube 11.

Referring to fig. 3, the bottom opening of the sludge channel 17 is connected to the sludge discharge annulus, and the width of the bottom opening is not smaller than the sludge discharge annulus.

Referring to fig. 4, the side wall of the swirl ring 15 is provided with inner swirl ports 25 uniformly distributed along the circumference; preferably, the screwing-on opening 25 is long-strip-shaped; which allows a flow of water having a higher pressure and agglomerated growing particles to flow to the end of the diffuser of the venturi tube 14 and to swirl into the annular sludge channel 17, which is depressurized by the ejector effect at the throat 16.

Referring to fig. 5, the throat 16 of the venturi tube 14 is provided with through holes 26 in an array shape uniformly distributed along the circumferential wall thereof; the through hole 26 and the start-up rotary opening 25 are arranged in the same inscribing direction; therefore, when the muddy water containing sludge particles entering the sludge channel 17 through the swirling mouth 25 reaches the throat 16, most of the particles are thrown to the outer side wall of the sludge channel 17 due to centrifugal force, and part of the particles still flowing against the outer side wall of the throat 16 slide through the outer side of the through hole 26 due to the same swirling direction as the inner contact direction of the through hole 26, and the swirling inertia of the particles separates most of the particles flowing through the through hole 26 from the water body where the particles are located, so that the water flow enters the throat from the through hole 26 due to the suction effect of the throat 16, and the particles slide through the outer side of the through hole 26 under the rotation inertia effect of the particles.

The bottom of each mounting hole 9 is connected with two opposite mud discharging slideways 19; the two opposite sludge discharge slideways 19 respectively extend into the sludge grooves 27 on two sides of the distribution channel 28 corresponding to the mounting hole 9.

Referring to fig. 6, the mud discharge chute 19 has a tile-shaped structure including an outer arch 20 and an inner arch 21 which are arranged in parallel with each other and are arched outward, and two side plates 22 for connecting the side edges of the inner and outer arches; the inner arch plate 20, the outer arch plate 21 and the two side plates 22 enclose a sandwich channel of the mud discharge slideway 19; the interlayer channel is provided with an inlet 23 which is positioned at the upper end of the mud discharging slideway 19 and is used for being communicated with the mud channel 17 of the Venturi inner member 10, and an outlet 24 which is positioned at the lower end of the mud discharging slideway 19 and extends into the mud collecting groove 27; the inlets 23 of the two sludge discharge chutes 19 which are opposite to each other are combined to form a complete circular inlet which just covers the sludge channel 17; the two side plates 22 on the same side of the two opposite sludge discharge chutes 19 are gradually far from top to bottom, so that the outlets 24 of the two opposite sludge discharge chutes 19 cannot form a complete circle, so as to allow the bottoms of the two opposite sludge discharge chutes 19 to extend across the distribution channel 28 and the connecting pipe 29 into the sludge grooves 27 on both sides of the distribution channel 28.

The above is merely an example of the preferred embodiments of the concept of the present invention, but the feasible embodiments of the present invention are not limited to the above, and the embodiments obtained by the modification manner such as replacement by the conventional means without creative efforts by those of ordinary skill in the art also belong to the scope of the feasible embodiments of the present invention, and the actual protection scope of the present invention is subject to the content of the claims.

Claims

1. A turbulent sedimentation tank comprises a tank body (1), wherein the interior of the tank body (1) is divided into a water inlet cavity (3) and a sedimentation cavity (7) which are positioned at the left side and the right side of a clapboard (4) by the clapboard (4); a water inlet unit is arranged on the side wall of the water inlet cavity (3); a plurality of water diversion ports (5) are arranged at the bottom of the partition plate (4) at intervals; distribution channels (28) with the same number as the water inlets (5) are arranged at the bottom in the sedimentation cavity (7); one end of the distribution channel (28) is connected with the water diversion port (5) in a fluid sealing mode and is used for receiving raw water from the water diversion port (5) from the water inlet cavity (3); a mud collecting groove (27) is formed between the adjacent distribution channels (28); a sealing plate (8) is arranged on the top end of the water diversion port (5) in the sedimentation cavity (7) to divide the sedimentation cavity (7) into a clear water area on the upper part of the sealing plate (8) and a sludge area on the lower part of the sealing plate (8); the sealing plate (8) is provided with a plurality of mounting holes (9) which are arranged in an array; each of the mounting holes (9) is located above the top of the distribution channel (28); a Venturi inner component (10) is arranged on one side of each mounting hole (9) above the closing plate (8); the venturi inner member (10) can receive raw water from the distribution channel (28), promote fine particles in the water to agglomerate and grow, and then discharge the grown particles into a sludge collection groove (27); the venturi inner member (10) comprises a housing and a venturi tube (14) located within the housing; an annular sludge channel (17) is formed between the Venturi tube (14) and the shell, and the tail end of a diffusion tube of the Venturi tube (14) is communicated with the top of the sludge channel (17); the shell comprises a lower shell tube (11) with a larger diameter positioned at the lower part, an upper shell tube (12) with a smaller diameter positioned at the upper part and a truncated cone-shaped connecting shell (13) connecting the lower shell tube (11) and the upper shell tube (12); the Venturi tube (14) is positioned in a space formed by the lower shell tube (11) and the connecting shell (13); the Venturi tube (14) is provided with a throat (16) and a water inlet (18) which is positioned at the bottom and used for raw water to flow in; the tail end of a diffusion pipe at the top of the Venturi tube is connected with the lower end of the upper shell tube (12) through a rotational flow ring (15); the Venturi tube (14), the lower shell tube (11), the upper shell tube (12), the connecting shell (13) and the rotational flow ring (15) are concentrically arranged, and the rotational flow ring (15) is communicated with the sludge channel (17) and the tail end of the diffusion tube of the Venturi tube (14); the side wall of the rotational flow ring (15) is provided with internally tangent spiral openings (25) which are uniformly distributed along the circumference; the screw-on opening (25) allows the water to flow to the tail end of the diffusion pipe of the Venturi pipe (14), and the water flow with higher pressure and agglomerated and grown particles rotates to enter the annular sludge channel (17) decompressed by the injection effect at the throat (16); the bottom of the mounting hole (9) is connected with two opposite mud discharging slideways (19); the two opposite mud discharging slideways (19) respectively extend into mud collecting grooves (27) on two sides of a distribution channel (28) corresponding to the mounting hole (9); the mud discharge chute (19) is provided with an interlayer channel; the interlayer channel is provided with an inlet (23) which is positioned at the upper end of the mud discharging slide way (19) and is used for being communicated with the mud channel (17) of the Venturi inner member (10), and an outlet (24) which is positioned at the lower end of the mud discharging slide way (19) and extends into the mud collecting groove (27); inlets (23) of two sludge discharge slideways (19) which are opposite to each other are combined to form a complete circular inlet which just covers the sludge channel (17); the lower parts of the two opposite mud discharging slideways (19) are gradually far away from top to bottom so as to allow the bottoms of the two opposite mud discharging slideways (19) to cross the distribution channel (28) and the connecting pipe (29) and extend into mud collecting grooves (27) at two sides of the distribution channel (28).

2. The turbulence sedimentation tank as claimed in claim 1, wherein: the vertical dimension of the distribution channel (28) in the length direction thereof is gradually reduced; the upper surface of the distribution channel (28) is provided with a plurality of connecting pipes (29) correspondingly connected with inlets of the Venturi inner component (10); the connecting tube (29) has a varying height along the length of the distribution channel (28).

3. The turbulence sedimentation tank as claimed in claim 2, wherein: the mounting hole (9) is concentrically arranged with the connecting pipe (29), the diameter of the mounting hole (9) is larger than that of the connecting pipe (29), so that a mud discharge annular gap is formed between the mounting hole and the connecting pipe, and the water inlet unit comprises a water inlet hole (2) arranged on the side wall of the water inlet cavity (3) and an overflow groove (6) positioned at the downstream of the water inlet hole (2).

4. The turbulence sedimentation tank as claimed in claim 1, wherein: the throat (16) of the Venturi tube (14) is provided with through holes (26) which are uniformly distributed along the circumferential wall in an array shape; the through hole (26) and the screwing-on opening (25) are internally tangent in the same direction; when the turbid water entering the sludge channel (17) through the swirling mouth (25) reaches the throat (16), at least part of the particles still flowing against the outer side wall of the throat (16) slide through the outer side of the through hole (26) due to the swirling inertia of the particles except large particles thrown to the outer side of the sludge channel (17) and do not enter the throat (16) through the through hole (26).