Cyclone desanding system for sewage with low solid content and control method of cyclone desanding system

Abstract

The invention belongs to the field of sewage treatment, and discloses a low-solid-content sewage cyclone desanding system and a control method thereof.The low-solid-content sewage cyclone desanding system comprises a pressure transmitter arranged on a water inlet pipe; the plurality of hydrocyclones are connected with the water inlet pipe; the plurality of first valves are arranged on an inlet pipeline of the cyclone and are associated with the pressure transmitter; a sand collecting chamber is arranged at a first sand discharging opening of the cyclone; the sand collecting chamber outlet end is provided with a second valve; the sand-water separator is connected with the outlet end of the second valve; the controller is connected with the pressure transmitter, the first valve, the cyclone, the second valve and the sand-water separator; the hydrocyclones, the first valves, the sand collecting chambers and the second valves are equal in number and are correspondingly arranged on the parallel branches, and the number of the parallel branches is three or more. The system can automatically regulate and control the operation of the cyclone according to the total water inlet pressure fluctuation, solves the problems of unstable operation flow state, poor sand removal effect and the like caused by water inlet flow fluctuation, is suitable for sand removal treatment of sewage with large water inlet fluctuation and low solid content, and is efficient and stable in operation and good in sand removal effect.

Description

Technical Field

[0001] The invention belongs to the field of sewage treatment equipment, and in particular relates to a low-solid content sewage cyclone sand removal system and a control method thereof. Background Art

[0002] Sewage pretreatment and sand removal is one of the indispensable links in sewage treatment plants. The effect of sand removal is directly related to the treatment effect and operation and maintenance workload of subsequent treatment units. Traditional sand removal systems mainly include horizontal flow sand settling tanks, aerated sand settling tanks or cyclone sand settling tanks, all of which are mainly in the form of civil engineering structures. All three require pumping or air lifting, and there are problems of sand blockage and wear. At the same time, all three have almost no effect on removing fine sand below 200μm. For this reason, the applicant has previously developed a high-precision cyclone sand removal equipment system (such as a sewage sand removal system disclosed in patent CN215288245U), which can effectively remove fine sand below 200μm, but it was found during use that there are still problems such as easy blockage and unstable sand removal effect.

[0003] In addition, when the sewage treatment plant is in operation, the liquid level control target of the lifting pump pool is mainly achieved by controlling the number of operating lift pumps or the operating frequency. However, the inlet flow rate fluctuates greatly between the rainy season and the dry season, and between the flood season and the non-flood season, and the coefficient of variation of the treated water volume can reach more than 1.5. At this time, the large fluctuation of the inlet flow rate will have a significant impact on the operation of the cyclone. The existing process mostly uses two cyclones, one for use and one for backup. The water inlet of the cyclone is manually switched by manual gates. The diameter of this type of manual gate is large, the operation is labor-intensive, and the switching is delayed. It cannot respond to the fluctuation of instantaneous water volume in time, which will cause the cyclone operating conditions and internal flow field to be unstable, and even the operating parameters are not within the normal working range, making the sand removal effect unstable. Summary of the invention

[0004] In view of the defects of the above-mentioned prior art, the present invention provides a low-solid content sewage cyclone sand removal system and a control method thereof. The system can automatically adjust and control the operation of the cyclone according to the fluctuation of the total water inlet pressure, so as to solve the problems of unstable operation flow state and poor sand removal effect caused by the fluctuation of the water inlet flow rate. The system is suitable for sand removal treatment of sewage with large fluctuation of water inlet volume and low solid content. The system operates efficiently and stably and has a good sand removal effect.

[0005] The technical solution adopted by the present invention is as follows:

[0006] A low solid content sewage cyclone sand removal system, comprising:

[0007] The pressure transmitter is installed on the water pipe;

[0008] A plurality of cyclones are arranged in parallel, and the upper inlet pipeline of each cyclone is connected to the water supply pipe via a pressure equalizing flow distributor;

[0009] A plurality of first valves, respectively disposed on the inlet pipeline of each of the cyclones, each of the first valves being associated with the pressure transmitter;

[0010] A sand collecting chamber, wherein the first sand discharge port at the lower part of each cyclone is connected to a sand collecting chamber;

[0011] A plurality of second valves, each of the outlet ends of the sand collecting chamber being provided with the second valve;

[0012] A sand-water separator connected to the outlet of each of the second valves and used for separating concentrated sand from water;

[0013] A controller, which is in telecommunication connection with the pressure transmitter, the first valve, the cyclone, the second valve and the sand-water separator;

[0014] The cyclones, the first valves, the sand collecting chambers and the second valves are equal in number and are arranged in a one-to-one correspondence on parallel branches, and the parallel branches include 3 or more.

[0015] In one embodiment of the present application, all the second valves are associated with each other, and each of the second valves is associated with the first valve on the same parallel branch;

[0016] and / or, all of the cyclones are associated with the pressure transmitter;

[0017] And / or, each of the cyclones is associated with the first valve on the corresponding inlet pipeline.

[0018] In one embodiment of the present application, all the sand collecting chambers are provided with a recoil air branch, and the recoil air branch is provided with a one-way air intake valve and an air intake switch valve, and the one-way air intake valve is arranged at the end of the recoil air branch, located in the sand collecting chamber; all the recoil air branches are connected to an air compressor;

[0019] A pressure monitor is provided on the pipeline between the first sand discharge port and the inlet of the sand collection chamber, and the pressure monitor is associated with the air injection switch valve.

[0020] In one embodiment of the present application, the one-way air intake valve comprises:

[0021] A valve body, wherein the valve body is a cylindrical structure, one end of which is a blind end, and the other end of which is open and communicated with a recoil gas branch;

[0022] A valve core is adapted to the interior of the valve body and is axially sealed and slidably disposed in the valve body;

[0023] An elastic member, disposed in the valve body and between the blind end of the valve body and the valve core;

[0024] Among them, a plurality of exhaust holes are distributed circumferentially on the side wall of the valve body. When the elastic member is reset, it pushes the valve core to block the exhaust holes. When the recoil gas branch introduces pressurized gas into the sand collecting chamber, the pressurized gas pushes the valve core to compress the elastic member to open the exhaust holes.

[0025] In one embodiment of the present application, the valve body further includes one or more of the following:

[0026] A limiting portion for limiting the position of the valve core is provided inside one end of the valve body opening, and when the valve core abuts against the limiting portion, the exhaust hole is blocked;

[0027] A drain hole is provided on the side wall of the valve body close to the blind end;

[0028] One end of the valve body opening is provided with an external thread, which is connected to the sand collecting chamber and / or the recoil gas branch through a threaded joint.

[0029] In one embodiment of the present application, the sand-water separator includes a sand settling hopper and a conveying mechanism; the sand settling hopper is provided with an overflow port, a drain port and an emptying port from top to bottom; the conveying mechanism is a spiral conveying mechanism, one end of which is connected to the bottom of the sand settling hopper, and the other end is provided with a second sand discharge port; the cyclone and the sand collecting chamber are directly connected up and down through a vertical pipe and are arranged above the sand settling hopper.

[0030] In one embodiment of the present application, the first valve is a pneumatic gate valve;

[0031] And / or, the second valve is a pneumatic pipe clamp valve;

[0032] And / or, the pressure equalizing flow distributor comprises a water inlet main pipe and at least three water outlet branch pipes, and the flow area of ​​the water inlet main pipe is greater than or equal to the sum of the flow areas of the water outlet branch pipes.

[0033] A control method for a low-solid content sewage cyclone sand removal system, using the low-solid content sewage cyclone sand removal system as described in any one of the above, comprises the following steps:

[0034] S100, obtaining the total water inlet pressure WP1 of the water pipe, and controlling the opening / closing quantity of the first valve and the opening and closing of the corresponding cyclone according to the total water inlet pressure WP1;

[0035] S200, recording the cumulative opening time t1 of each first valve, when the cumulative opening time t1 of any first valve ≥ the preset time T0, the second valve on the parallel branch where the first valve is located meets the opening sand discharge condition; when the cumulative opening time t1 of any first valve < the preset time T0, the second valve on the parallel branch where the first valve is located does not meet the opening sand discharge condition;

[0036] S300, the sand-water separator operates according to an operation cycle, each of which includes a plurality of process links, and the second valve is opened to discharge sand only in the water inlet link of each operation cycle.

[0037] In one embodiment of the present application, in step S100:

[0038] When the total water inlet pressure WP1 is within the normal working pressure range P 下限值 ~P 上限值 When the time is within 2 hours, open N first valves and their corresponding cyclones, N≥2;

[0039] When the total water inlet pressure WP1 is less than P 下限值 When N - The first valve and its corresponding cyclone, 1≤N - <N;

[0040] When the total water inlet pressure WP1 is greater than P 上限值 When N + The first valve and its corresponding cyclone, N + >N and N + ≥3.

[0041] In one embodiment of the present application, in step S200:

[0042] All the second valves are set to a cyclical start-up sequence. When the start-up sequence of any second valve is reached and the second valve meets the conditions for opening and draining sand, the second valve is opened to drain the sand underflow. When the sand discharge is opened for a predetermined sand discharge time T, 排 Then the second valve is automatically closed; when the start sequence of any second valve is in turn, if the second valve does not meet the conditions for opening and discharging sand, the second valve will not be opened, and the start sequence will be in turn to the next second valve;

[0043] When any of the first valves is opened, the opening time of the first valve is recorded. When the first valve is closed, the timing is stopped and the record is not cleared. When the first valve is opened again, the timing is continued until the accumulated opening time t1 ≥ the preset time T0, and the corresponding second valve meets the opening sand discharge condition. When the second valve that meets the opening sand discharge condition takes turns to the start sequence and opens to discharge sand, the accumulated opening time t1 of the corresponding first valve is cleared and the next round of timing is started again.

[0044] When the second valve is opened to discharge the underflow sand, the corresponding first valve is in a closed state.

[0045] In one embodiment of the present application, in step S300: the multiple process links of the operation cycle include an initialization link, a water intake link, a sedimentation link, a drainage link and a sand separation link which are arranged in sequence; the second valve is opened to discharge sand only in the water intake link of each operation cycle, and then the sand-water separator processes the subsequent links, and the next operation cycle can only be started after one operation cycle ends; if the previous operation cycle has not ended, and the next second valve has met the conditions for opening and discharging sand, the next second valve will delay waiting.

[0046] Compared with the prior art, the present invention has the following beneficial effects:

[0047] 1. The low-solid content sewage cyclone sand removal system of the present invention is provided with a pressure transmitter to detect the total water inlet pressure, and is associated with the first valve on the cyclone parallel branch. The opening and closing operation of the cyclone branch is automatically controlled according to the change of the total water inlet pressure, which can effectively solve the problems of unstable operation flow state and poor sand removal effect caused by water inlet fluctuation; a sand collecting chamber and a second valve are provided at the bottom of the cyclone, which can discharge sand intermittently, adapt to the sand removal treatment of low-solid content sewage, and can effectively increase the sand concentration and reduce the hydraulic load of the sand-water separator; the low-solid content sewage cyclone sand removal system is efficient and stable in operation and has a good sand removal effect.

[0048] 2. By associating the first valve with the second valve on the same parallel branch, the automatic opening of the second valve is controlled according to the accumulated opening time of the first valve, thereby realizing automatic control of intermittent underflow sand discharge; wherein, the first valve and the second valve are both pneumatic valves, and the second valve is a pneumatic pipe clamp valve, which can realize automatic and rapid opening and closing, avoid problems such as sealing failure caused by sand jamming and wear, and can realize accurate dynamic flow regulation and accurate underflow sand discharge control, which can effectively improve the stability and reliability of system operation.

[0049] 3. A backwash air branch is set up to connect with the sand collecting chamber, which can backwash the sand collecting chamber and the first sand discharge port, effectively solving the problems of fine sand compaction in the sand collecting chamber and blockage of the first sand discharge port at the bottom of the cyclone, ensuring smooth intermittent sand discharge and stable operation of the system.

[0050] 4. The cyclone and sand collecting chamber are arranged above the sand settling hopper through a vertical pipe, so that the cyclone, sand collecting chamber and sand settling hopper are directly connected along the gravity direction, which improves the structural layout of the equipment, avoids the setting of horizontal pipe sections, and thus avoids the problem of sand accumulation and blockage in the horizontal pipe sections, and at the same time can save more than 20% of the floor space.

[0051] 5. The control method of the present application realizes the automatic control and coordinated control of the three parts of the cyclone water inlet, the intermittent sand discharge of the cyclone underflow and the sand-water separator, so that the low-solid content sewage cyclone sand removal system of the present application can be fully automated and intelligently controlled, which can effectively cope with the fluctuation of instantaneous water volume, ensure the smoothness of the cyclone and the stability of the operating conditions, ensure the sand removal effect, and at the same time ensure the system's rapid response, precise control, efficient and stable operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0053] Figure 1 This is a schematic diagram of the process of a low-solid content sewage cyclone sand removal system in this application.

[0054] Figure 2 It is a front view schematic diagram of the installation structure of a low-solid content sewage cyclone sand removal system in this application.

[0055] Figure 3 It is a side view schematic diagram of the installation structure of a low-solid content sewage cyclone sand removal system in this application.

[0056] Figure 4 Schematic diagram of the structure for setting up a recoil gas branch for the sand collecting chamber.

[0057] Figure 5 This is a schematic diagram of the structure of the one-way air intake valve when backwashing is not performed.

[0058] Figure 6 This is a schematic diagram of the state structure of the one-way air intake valve during backwashing.

[0059] Figure 7 for Figure 6 Cross-sectional view along the AA direction.

[0060] Figure 8 The figure is a schematic diagram of the structure of an implementation scheme of a pressure equalizing flow distributor.

[0061] Fig. 9 It is a schematic structural diagram of another implementation scheme of the pressure equalizing flow distributor.

[0062] Fig.10 This is a flow chart of the control method of the low solid content sewage cyclone sand removal system in this application.

[0063] Reference numerals:

[0064] 1. Pressure transmitter;

[0065] 2. Pressure equalizing flow distributor; 21. Water inlet main pipe; 22. Water outlet branch pipe;

[0066] 3. The first valve;

[0067] 4. Cyclone; 41. First row of sand outlets;

[0068] 5. Sand collection room;

[0069] 6. Second valve;

[0070] 7. Sand-water separator; 71. Sand settling hopper; 711. Overflow port; 712. Drain port; 713. Emptying port; 72. Conveying mechanism; 721. Second sand discharge port.

[0071] 8. Recoil air branch; 81. One-way air inlet valve; 811. Valve body; 8111. Exhaust hole; 8112. Limiting part; 8113. Drain hole; 812. Valve core; 813. Elastic part; 82. Air switch valve. DETAILED DESCRIPTION

[0072] In the following, only some exemplary embodiments are briefly described. As those skilled in the art will appreciate, the described embodiments may be modified in various ways without departing from the spirit or scope of the present invention. Therefore, the drawings and descriptions are considered to be exemplary and non-restrictive in nature.

[0073] In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "back", "length", "vertical", "horizontal", "top", "bottom", "inside", "outside", "axial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, or are the orientations or positional relationships in which the products of the present invention are conventionally placed when in use, or are the orientations or positional relationships conventionally understood by those skilled in the art. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0074] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0075] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or a communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0076] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0077] The disclosure below provides many different embodiments or examples to realize different structures of the present invention. In order to simplify the disclosure of the present invention, the parts and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present invention.

[0078] The embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0079] like Figures 1 to 3 As shown, an embodiment of the present invention provides a low-solid content sewage cyclone sand removal system, which includes: a pressure transmitter 1, multiple cyclones 4, multiple first valves 3, multiple sand collection chambers 5, multiple second valves 6, a sand-water separator 7 and a controller (not shown in the figure), etc. Among them, multiple cyclones 4 are arranged in parallel to form multiple parallel branches, and each parallel branch is sequentially provided with a first valve 3, a cyclone 4, a sand collection chamber 5, a second valve 6, etc.

[0080] Specifically, the pressure transmitter 1 is arranged on the water pipe to detect the total water inlet pressure and can convert the pressure into an electrical signal to determine the water inlet flow rate.

[0081] Multiple cyclones 4 are arranged in parallel after the pressure transmitter 1, that is, multiple parallel branches are arranged after the pressure transmitter 1, and each parallel branch is provided with a cyclone 4. The inlet pipelines on the upper parts of the multiple cyclones 4 are connected to the water pipe through the pressure equalizing flow distributor 2, and the water flow is evenly distributed into the opened cyclones 4, so that the water inlet pressure of the cyclones 4 running at the same time remains consistent.

[0082] A plurality of first valves 3 are respectively arranged on the inlet pipeline of each cyclone 4, that is, a first valve 3 is correspondingly arranged on the inlet pipeline of each cyclone 4, and the first valve 3 is opened and closed to control whether the water flows into the corresponding cyclone 4. Each first valve 3 is associated with the pressure transmitter 1 for linkage control, and can control the opening or closing of each first valve 3 according to the change of the total water inlet pressure (that is, the flow change) detected by the pressure transmitter 1, thereby controlling the number of cyclones 4 in operation, realizing automatic and rapid adjustment and balancing of the water flow entering the cyclone 4, avoiding the impact of the fluctuation of the water inlet flow on the cyclone 4 and affecting the sand removal effect, and ensuring the efficient and stable operation of the cyclone sand removal system.

[0083] Multiple sand collecting chambers 5 are respectively arranged at the first sand discharge port 41 at the bottom of each cyclone 4, that is, each first sand discharge port 41 at the bottom of each cyclone 4 is connected to a sand collecting chamber 5. The sand collecting chamber 5 is used to collect and temporarily store solid particles precipitated by the cyclone 4.

[0084] A plurality of second valves 6 are respectively arranged on the outlet pipe of each sand collecting chamber 5 , that is, each sand collecting chamber 5 is provided with a second valve 6 , and the discharge of sand and water in the sand collecting chamber 5 is controlled by switching the second valve 6 .

[0085] The sand-water separator 7 is connected to the outlet of each second valve 6, that is, the sand-water separator 7 is connected to the outlet of each sand collecting chamber 5, and is used to perform sedimentation, drainage, sand separation and other treatments on the concentrated sand collected in the sand collecting chamber 5, so as to achieve complete separation of sand and water, thereby achieving sand removal treatment of sewage. Preferably, a set of sand-water separators 7 is included, which can respectively process the concentrated sand water discharged from each sand collecting chamber 5, saving equipment investment; of course, the sand-water separators 7 can also be provided in multiple sets.

[0086] A sand collecting chamber 5 and a second valve 6 are arranged at the bottom of the cyclone 4 to realize intermittent sand discharge, which is suitable for sand removal treatment of low-solid content sewage, can effectively increase the sand concentration and reduce the hydraulic load of the sand-water separator 7; the low-solid content sewage cyclone sand removal system operates efficiently and stably, and has a good sand removal effect.

[0087] The controller (not shown in the figure) is connected to the pressure transmitter 1, the first valve 3, the cyclone 4, the second valve 6 and the sand-water separator 7 by telecommunication, and the automatic intelligent control of the system is realized by the controller. The controller is preferably a PLC controller.

[0088] Among them, the number of cyclones 4, the first valve 3, the sand collecting chamber 5 and the second valve 6 is equal, and they are arranged one by one on the parallel branches. The parallel branches of the system include 3 or more, that is, at least 3 cyclones 4 and parallel branches. Setting at least 3 parallel branches can be well adjusted according to the fluctuation of the inlet flow rate, adapt to the situation of reducing and increasing the fluctuation of the water volume, and have a wider range of adaptability and stronger adaptability.

[0089] Preferably, the second valves 6 on all parallel branches are associated with each other, and each second valve 6 is associated with the first valve 3 on the same parallel branch.

[0090] For example, when the sand-water separator 7 is a set, and the sand-water separator 7 only processes a fixed number (such as one or two) of concentrated sand deposited in the sand collecting chamber 5 at a time, then only less than or equal to the fixed number of second valves 6 can be opened at a time to discharge the concentrated sand into the sand-water separator 7; all the second valves 6 are associated to realize associated control, which can effectively avoid the problem of more second valves 6 being opened at the same time, causing the sand-water separator 7 to operate overloaded.

[0091] The second valve 6 is associated with the first valve 3, and can be linked to control the automatic opening of the second valve 6 by accumulating the opening time of the first valve 3. That is, when the first valve 3 is opened, the hydrocyclone 4 is running, and the opening time of the first valve 3 is calculated. When the opening time accumulates to the set time, the second valve 6 can be controlled to open automatically for intermittent concentrated sand discharge. Automatic control is achieved to avoid the second valve 6 from opening too early or too late, which affects the sand removal efficiency and effect of the hydrocyclone 4, as well as the periodic operation of the sand-water separator 7.

[0092] Preferably, the first valve 3 is a pneumatic gate valve; the second valve 6 is a pneumatic pipe clamp valve. The use of pneumatic valves can realize automatic and rapid closing of the valve, realize rapid and precise control while realizing automatic control, with low cost and strong practicality. The second valve 6 at the bottom of the sand collecting chamber 5 uses a pneumatic pipe clamp valve to replace the conventional electric valve. The pneumatic actuator can realize the sand discharge opening and closing control time of less than 5s. At the same time, the structure of the pipe clamp valve can effectively avoid the sealing failure caused by sand jamming and wear. Among them, the first valve 3 is controlled by the power-off normally open mode, and the second valve 6 is controlled by the power-off normally closed mode, with low operating energy consumption.

[0093] In one embodiment, all cyclones 4 are associated with the pressure transmitter 1 to achieve linkage, and the number of cyclones 4 in operation is controlled according to the change in the total water inlet pressure detected by the pressure transmitter 1. And / or, each cyclone 4 is associated with the first valve 3 on the corresponding branch to achieve linkage, when the first valve 3 on its inlet pipe is opened, the cyclone 4 also starts to operate at the same time, and when the first valve 3 on its inlet pipe is closed, the cyclone 4 is also closed, to achieve synchronous automatic control.

[0094] Preferably, each sand collecting chamber 5 is provided with a recoil air branch 8, and each recoil air branch 8 is provided with a one-way air inlet valve 81 and an air-injection switch valve 82. Among them, the one-way air inlet valve 81 is arranged at the end of the recoil air branch 8, located in the sand collecting chamber 5; the air-injection switch valve 82 is preferably a switch ball valve. All recoil air branches 8 are connected to an air compressor or a high-pressure air source (not shown in the figure), and can share one air compressor or one high-pressure air source to provide pressurized gas. Of course, multiple air compressors or multiple high-pressure air sources can also be set. The air-injection switch valve 82 is used to control the on-off of the recoil air branch, and the one-way air inlet valve 81 prevents the sewage, fine sand, etc. in the sand collecting chamber 5 from reflux and blocking the air pipe.

[0095] Furthermore, a pressure monitor (not shown in the figure) is provided on the pipeline between the first sand discharge port 41 at the bottom of the cyclone 4 and the inlet at the upper part of the sand collecting chamber 5. The pressure monitor is connected to the controller and is associated with the corresponding air-injection switch valve 82 on the same parallel branch. When the first sand discharge port 41 is opened and the pressure monitor detects insufficient pipeline pressure, it indicates that the sand discharge channel and / or the first sand discharge port 41 are blocked, and the air-injection switch valve 82 can be opened to perform the automatic air-injection mode.

[0096] The backwash air branch 8 is provided to flush the sand collecting chamber 5 and the first sand discharge port 41 at the bottom of the cyclone 4, which can effectively solve the problems of blockage of the sand collecting chamber 5 and the first sand discharge port 41 caused by the internal sand compaction, hardening, and "arching" caused by a long accumulation time, operating pressure and gravity.

[0097] like Figures 4 to 7 As shown, in one embodiment, the one-way air inlet valve 81 includes a valve body 811, a valve core 812 and an elastic member 813. The valve body 811 is a cylindrical structure, one end of which is a blind end, and the other end is open and communicated with the recoil gas branch 8; the valve core 812 is adapted to the internal cavity of the valve body 811, and is axially sealed and slidably arranged in the valve body 811; the elastic member 813 is arranged in the valve body 811, and is located between the blind end of the valve body 811 and the valve core 812. The elastic member 813 is preferably a compression spring, and of course it can also be other elastic components with compression and reset functions. Among them, a plurality of exhaust holes 8111 are circumferentially distributed on the side wall of the valve body 811 at positions corresponding to the positions of the valve core 812 when the valve core 812 is reset. When the elastic member 813 is reset, the valve core 812 is pushed to block the exhaust holes 8111. When the backwash gas branch 8 is ventilated and pressurized gas is introduced into the sand collecting chamber 5, the pressurized gas can push the valve core 812 to compress the elastic member 813 and move toward the blind end of the valve body 811, so that the exhaust holes 8111 are opened. One-way air intake is realized, and the exhaust holes 8111 are closed when no air is injected.

[0098] Furthermore, a limiting portion 8112 is provided inside the open end of the valve body 811 to limit the valve core 812. When the elastic member 813 extends and resets to push the valve core 812 to abut against the limiting portion 8112, the valve core 812 blocks the exhaust hole 8111. The limiting portion 8112 can be provided to limit the positioning of the valve core 812, ensuring accurate and stable one-way blocking.

[0099] The valve body 811 is provided with a drain hole 8113 on the side wall near the blind end. The drain hole 8113 is provided to prevent the valve body 811 from being blocked by dirt and ensure that the valve core 812 can slide smoothly in a sealed manner.

[0100] In one embodiment, an external thread is provided on the outside of one end of the opening of the valve body 811, and the valve body 811 is threadedly connected to the side wall of the sand collecting chamber 5 through a threaded joint; or, the valve body 811 is threadedly connected to the pipeline of the recoil gas branch 8 through a threaded joint; or, the valve body 811 is threadedly connected to the side wall of the sand collecting chamber 5 and the pipeline of the recoil gas branch 8 through a threaded joint. The valve body 811 is installed through a threaded connection, and its installation, disassembly, and maintenance are convenient.

[0101] like Figures 1 to 3 As shown, the sand-water separator 7 includes a sand hopper 71 and a conveying mechanism 72. The sand hopper 71 is provided with an overflow port 711, a drain port 712 and an emptying port 713 from top to bottom; the overflow port 711 is level with or higher than the concentrated sand discharge port; the drain port 712 is located in the middle of the sand hopper 71, and is used to discharge the upper layer of clear water after the concentrated sand is precipitated; the emptying port 713 is located at the bottom of the sand hopper 71, and is used for emptying; and the overflow port 711, the drain port 712 and the emptying port 713 are all provided with a switch valve. The conveying mechanism 72 is preferably a screw conveying mechanism, one end of which is connected to the bottom of the sand hopper 71, and the other end extends to the outside of the sand hopper 71, and the other end is provided with a second sand discharge port 721, and the solid sand particles deposited at the bottom of the sand hopper 71 are transported and discharged by the conveying mechanism 72, so as to achieve the separation of sand and water of the concentrated sand. The sand-water separator 7 has a simple structure and is convenient for sand-water separation.

[0102] Preferably, the cyclone 4 and the sand collecting chamber 5 are directly connected up and down through a vertical pipe and arranged above the sand settling hopper 71, so that the concentrated sand in the cyclone 4 and the sand collecting chamber 5 can flow into the sand settling hopper 71 of the sand-water separator 7 below by gravity; the arrangement of horizontal pipe sections is avoided, thereby avoiding the blockage problem of horizontal pipe sections, and at the same time can effectively save floor space, which can save 20% or more of floor space.

[0103] like Figure 8 and Fig. 9As shown, the pressure-equalizing flow distributor 2 includes a water inlet main pipe 21 connected to the incoming water pipe and a water outlet branch pipe 22 connected to the inlet pipe of the cyclone 4. The water outlet branch pipes 22 include at least 3, and each water outlet branch pipe 22 is respectively connected to a corresponding cyclone 4. Among them, the flow area (i.e., the cross-sectional area) of each water outlet branch pipe 22 is equal, and the flow area of ​​the water inlet main pipe 21 in each pressure-equalizing flow distributor 2 is greater than or equal to the sum of the flow areas of each water outlet branch pipe 22. That is, when the flow area of ​​the water inlet main pipe 21 is D, the flow area of ​​the water outlet branch pipe 22 is d, and the number of water outlet branches 22 is N, D≥N×d. Further preferably, D=k×N×d, where 1.1≤k≤1.4, can effectively ensure the balanced and stable water inflow of each water outlet branch pipe 22 and the cyclone 4, while avoiding energy waste caused by excessive pressure of the water pump of the water inlet pipe.

[0104] Further, when the number of the outlet branch pipe 22 and the cyclone 4 is 3, it is preferred to adopt Figure 8 As shown, outlet branches 22 are arranged at intervals along the length direction of the water inlet main pipe 21, and the three outlet branches 22 are perpendicular to the water inlet main pipe 21, located on the same plane, and arranged parallel to each other, which can ensure that the water pressure entering the cyclone 4 is evenly distributed, and the installation is convenient and space-saving.

[0105] When the number of the outlet branch pipes 22 and the cyclones 4 is greater than or equal to 4, the following method is adopted: Fig. 9 As shown, outlet ends are evenly arranged along the circumference of the water inlet main pipe 21 to connect with the water outlet branch pipes 22, and the water inlet main pipe 21 is parallel to each water outlet branch pipe 22. This can effectively ensure that the water outlet flow of each water outlet branch pipe 22 tends to be consistent, thereby ensuring that the water inlet pressure of each cyclone 4 is balanced and stable.

[0106] See also Fig.10 Based on the same invention purpose, the embodiment of the present invention also provides a control method for a low-solid content sewage cyclone sand removal system. The control method is implemented based on the low-solid content sewage cyclone sand removal system described above, and includes the following steps:

[0107] S100, obtaining the total water inlet pressure WP1 of the water pipe, and controlling the opening / closing quantity of the first valve 3 and the opening and closing of the cyclone 4 on the corresponding parallel branch according to the total water inlet pressure WP1.

[0108] S200, record the cumulative opening time t1 of each first valve 3. When the cumulative opening time t1 of any first valve 3 is ≥ the preset time T0, the second valve 6 on the parallel branch where the first valve 3 is located meets the opening and sand discharge conditions; conversely, when the cumulative opening time t1 of any first valve 3 is < the preset time T0, the second valve 6 on the parallel branch where the first valve 3 is located does not meet the opening and sand discharge conditions.

[0109] S300, the sand-water separator 7 operates according to an operation cycle, each operation cycle includes a plurality of process links, and the second valve 6 is opened to discharge sand only in the water inlet link of each operation cycle.

[0110] Preferably, in step S100:

[0111] When the total water inlet pressure WP1 is within the normal working pressure range P 下限值 ~P 上限值 When the water volume is within the normal operation range, N first valves 3 and their corresponding cyclones 4 are opened, wherein N≥2. That is, when the water volume is within the normal operation range, at least two cyclones 4 should be opened.

[0112] When the total water inlet pressure WP1 is less than P 下限值 When N - The first valve 3 and its corresponding cyclone 4 are used for sand removal, wherein 1≤N - <N. That is, when the total water inlet pressure / water inlet volume is lower than the lower limit of the normal operating water volume, some cyclones 4 and their water inlets are automatically closed, but at least one cyclone 4 must remain open to ensure that the sewage distribution system is not interrupted when the flow rate is low.

[0113] When the total water inlet pressure WP1 is greater than P 上限值 When N + The first valve 3 and its corresponding cyclone 4 are used for sand removal, wherein N + >N and N + ≥3. That is, when the total water inlet pressure / water inlet volume is higher than the upper limit of the normal operating water volume, the water inlet of more cyclones 4 is automatically opened to increase the number of running cyclones 4 and parallel branches to meet the situation of increased water inlet volume, ensure that the water inlet flow / pressure of the running cyclones 4 is always balanced and stable, and the cyclone sand removal effect is reliable.

[0114] Among them, the normal working pressure range P 下限值 ~P 上限值 Parameters should be set in the system controller, usually between 0.08 and 0.15 MPa.

[0115] Furthermore, a corresponding priority is set for each cyclone 4 and its corresponding first valve 3, such as a part of the cyclones 4 and its corresponding first valve 3 is set to normally open for water inlet; another part of the cyclones 4 and its corresponding first valve 3 is set to control start and stop according to the change of the total water inlet pressure, and another part of the cyclones 4 and its corresponding first valve 3 is set with different priorities. For example, when there are 3 cyclones 4, cyclone 1# is set to normally open for water inlet, and the other two cyclones 2# and 3# are started and stopped according to the change of the total water inlet pressure; and among them, the priority of opening: cyclone 2# is prior to cyclone 3#; the priority of closing: cyclone 3# is prior to cyclone 2#.

[0116] Preferably, in step S200:

[0117] All second valves 6 are set to a cyclical start-up sequence. When the start-up sequence of any second valve 6 is reached and the second valve 6 meets the conditions for opening and draining sand, the second valve 6 is opened to drain the sand at the bottom flow. When the sand discharge is opened for a predetermined sand discharge time T, 排 When the start sequence of the second valve 6 is in turn, if the second valve 6 does not meet the conditions for opening and discharging sand, the second valve 6 will not be opened, and the start sequence will take turns to the next second valve 6.

[0118] When any first valve 3 is opened, the opening time of the first valve 3 starts to be recorded; when the first valve 3 is closed, the timing is stopped and the record is not reset; when the first valve 3 is opened again, the timing continues to be recorded until the cumulative opening time t1 ≥ the preset time T0, and the second valve 6 corresponding to the first valve 3 meets the opening and sand discharge conditions; when the second valve 6 that meets the opening and sand discharge conditions takes turns to the start sequence and opens for sand discharge, the corresponding cumulative opening time t1 of the first valve 3 is reset, and the next round of timing is re-entered.

[0119] When the second valve 6 is opened to discharge the underflow sand, the corresponding first valve 3 should be linked to be in a closed state to avoid the operation fluctuation of the cyclone 4, reduce the amount of water carried when the concentrated sand is discharged, and reduce the operation load of the sand-water separator 7.

[0120] Preferably, step S200 also includes: when the cumulative opening time t1 of any first valve 3 is greater than 0 and less than the preset time T0, and the first valve 3 is closed for a time for longer than the shutdown time set by the system, the second valve 6 on the parallel branch where the first valve 3 is located also meets the conditions for opening and discharging sand. The concentrated sand in the sand collecting chamber 5 and the cyclone 4 on the parallel branch after short-term operation can be discharged in time to avoid the concentrated sand staying in the sand collecting chamber 5 for a long time due to insufficient cumulative operation time, which affects the emptying and maintenance of the corresponding parallel branch. Preferably, in step S300:

[0121] The operation cycle of the sand-water separator 7 includes multiple process links, including the initialization link, water intake link, sedimentation link, drainage link and sand separation link set in sequence; the second valve 6 is opened to discharge sand only in the water intake link of each operation cycle, and then the sand-water separator 7 processes the subsequent links, and the next operation cycle can only start after one operation cycle ends; if the previous operation cycle has not ended, and the next second valve 6 has met the conditions for opening and discharging sand, the next second valve 6 will delay waiting. Ensure that the sand and water separation of the sand-water separator 7 is complete in each operation cycle, the sand and water separation effect is stable, and avoid overflow, operation cycle confusion and other problems.

[0122] In summary, the low-solid content sewage cyclone sand removal system is provided with a pressure transmitter 1 to detect the total water inlet pressure, and is associated with the first valve 3 on the parallel branch of the cyclone 4, and automatically controls the opening and closing operation of the cyclone 4 branch according to the change of the total water inlet pressure, which can effectively solve the problems of unstable operation flow state and poor sand removal effect caused by water inlet fluctuation; a sand collecting chamber 5 and a second valve 6 are provided at the bottom of the cyclone 4, and sand can be discharged intermittently, which is suitable for the sand removal treatment of low-solid content sewage, and can effectively increase the sand concentration and reduce the hydraulic load of the sand-water separator 7; the low-solid content sewage cyclone sand removal system is efficient and stable in operation and has a good sand removal effect.

[0123] By associating the first valve 3 with the second valve 6 on the same parallel branch, and controlling the automatic opening of the second valve 6 according to the accumulated opening time of the first valve 3, automatic control of intermittent underflow sand discharge can be achieved; wherein, both the first valve and the second valve are pneumatic valves, and the second valve is a pneumatic pipe clamp valve, which can achieve automatic and rapid opening and closing, avoid problems such as sealing failure caused by sand jamming and wear, and can achieve precise dynamic flow regulation and precise underflow sand discharge control, effectively improving the stability and reliability of system operation.

[0124] A backwash air branch 8 is provided in the sand collecting chamber 5 to backwash the sand collecting chamber 5 and the first sand discharge port 41, which can effectively solve the problems of fine sand compaction in the sand collecting chamber 5 and blockage of the first sand discharge port 41 at the bottom of the cyclone 4, and ensure smooth intermittent sand discharge.

[0125] The cyclone 4 and the sand collecting chamber 5 are directly connected up and down through a vertical pipe and arranged above the sand settling hopper 71, so that the cyclone 4, the sand collecting chamber 5 and the sand settling hopper 71 are directly connected along the gravity direction, which improves the structural layout of the equipment, avoids the arrangement of a horizontal pipe section, and further avoids the problem of sand accumulation and blockage in the horizontal pipe section, and at the same time can save more than 20% of the floor space.

[0126] The control method of the low-solid content sewage cyclone sand removal system realizes the automatic control and coordinated control of the three parts of the cyclone 4 water inlet, the intermittent sand discharge of the bottom flow of the cyclone 4 and the sand-water separator 7, so that the low-solid content sewage cyclone sand removal system of the present application can be fully automated and intelligently controlled, and can effectively cope with the fluctuation of instantaneous water volume, ensure the smoothness of the inside of the cyclone 4 and the stable operating conditions, ensure the sand removal effect, and at the same time ensure the system's rapid response, precise control, efficient and stable operation.

Claims

1. A low solid content sewage cyclone sand removal system, characterized in that: include: A pressure transmitter (1) is provided on the water pipe; A plurality of cyclones (4) are arranged in parallel, and the upper inlet pipeline of each cyclone (4) is connected to the water pipe via a pressure equalizing flow distributor (2); A plurality of first valves (3), respectively provided on the inlet pipeline of each cyclone (4), each first valve (3) being associated with the pressure transmitter (1); A sand collecting chamber (5), wherein the first sand discharge port (41) at the lower portion of each cyclone (4) is connected to a sand collecting chamber (5); A plurality of second valves (6), wherein the outlet end of each sand collecting chamber (5) is provided with the second valve (6); A sand-water separator (7), connected to the outlet end of each second valve (6), for separating concentrated sand from water; A controller is connected to the pressure transmitter (1), the first valve (3), the cyclone (4), the second valve (6) and the sand-water separator (7) via telecommunication; The cyclones (4), the first valves (3), the sand collecting chambers (5) and the second valves (6) are equal in number and are arranged in a one-to-one correspondence on the parallel branches, and the parallel branches include three or more.

2. The low solid content sewage cyclone sand removal system according to claim 1 is characterized in that: All the second valves (6) are associated with each other, and each of the second valves (6) is associated with the first valve (3) on the same parallel branch; and / or, all of the cyclones (4) are associated with the pressure transmitter (1); And / or, each of the cyclones (4) is associated with the first valve (3) on the corresponding inlet pipeline.

3. The low solid content sewage cyclone sand removal system according to claim 1 or 2, characterized in that: All the sand collecting chambers (5) are provided with a recoil air branch (8), and the recoil air branch (8) is provided with a one-way air inlet valve (81) and an air on-off valve (82). The one-way air inlet valve (81) is provided at the end of the recoil air branch (8) and is located inside the sand collecting chamber (5); all the recoil air branches (8) are connected to an air compressor; A pressure monitor is provided on the pipeline between the first sand discharge port (41) and the inlet of the sand collecting chamber (5), and the pressure monitor is associated with the air injection switch valve (82).

4. The low solid content sewage cyclone sand removal system according to claim 3 is characterized in that: The one-way air intake valve (81) comprises: A valve body (811), the valve body (811) is a cylindrical structure, one end of which is a blind end, and the other end of which is open and communicates with the recoil gas branch (8); A valve core (812) is adapted to the interior of the valve body (811) and is axially and sealingly slidably disposed within the valve body (811); An elastic member (813) is provided in the valve body (811) and is located between the blind end of the valve body (811) and the valve core (812); A plurality of exhaust holes (8111) are circumferentially distributed on the side wall of the valve body (811), and when the elastic member (813) is reset, it pushes the valve core (812) to block the exhaust holes (8111); when the backwash gas branch (8) introduces pressurized gas into the sand collecting chamber (5), the pressurized gas pushes the valve core (812) to compress the elastic member (813) to open the exhaust holes (8111).

5. The low solid content sewage cyclone sand removal system according to claim 4, characterized in that: The valve body (811) further comprises one or more of the following: A limiting portion (8112) for limiting the position of the valve core (812) is provided inside the open end of the valve body (811), and when the valve core (812) abuts against the limiting portion (8112), the exhaust hole (8111) is blocked; A drain hole (8113) is provided on the side wall of the valve body (811) near the blind end; One open end of the valve body (811) is provided with an external thread, which is connected to the sand collecting chamber (5) and / or the backwash gas branch (8) via a threaded joint.

6. The low solid content sewage cyclone sand removal system according to claim 1, characterized in that: The sand-water separator (7) comprises a sand hopper (71) and a conveying mechanism (72); the sand hopper (71) is provided with an overflow port (711), a drain port (712) and an emptying port (713) from top to bottom; the conveying mechanism (72) is a spiral conveying mechanism, one end of which is connected to the bottom of the sand hopper (71) and the other end of which is provided with a second sand discharge port (721); the cyclone (4) and the sand collecting chamber (5) are directly connected to each other via a vertical pipe and are arranged above the sand hopper (71).

7. The low-solids-content sewage cyclone sand removal system according to claim 1 or 2, characterized in that: The first valve (3) is a pneumatic gate valve; And / or, the second valve (6) is a pneumatic pipe clamp valve; And / or, the pressure-equalizing flow distributor (2) comprises a water inlet main pipe (21) and at least three water outlet branch pipes (22), and the flow area of ​​the water inlet main pipe (21) is greater than or equal to the sum of the flow areas of the water outlet branch pipes (22).

8. A control method for a low-solids wastewater cyclone sand removal system, characterized in that: The low-solid content sewage cyclone sand removal system according to any one of claims 1 to 7 comprises the following steps: S100, obtaining the total water inlet pressure WP1 of the water pipe, and controlling the opening / closing number of the first valve and the opening and closing of the corresponding cyclone according to the total water inlet pressure WP1; S200, recording the cumulative opening time t1 of each first valve. When the cumulative opening time t1 of any first valve is greater than or equal to the preset time T0, the second valve on the parallel branch where the first valve is located meets the opening and sand discharge conditions. When the cumulative opening time t1 of any first valve is less than the preset time T0, the second valve on the parallel branch where the first valve is located does not meet the opening and sand discharge conditions. S300, the sand-water separator operates according to an operation cycle, each of the operation cycles includes multiple process links, and the second valve is opened to discharge sand only in the water inlet link of each operation cycle.

9. The method for controlling a low-solids-content sewage cyclone sand removal system according to claim 8, characterized in that: In step S100: When the total water inlet pressure WP1 is within the normal working pressure range P 下限值 ~P 上限值 When the time is within 1 second, open N first valves and their corresponding cyclones, N≥2; When the total water inlet pressure WP1 is less than P 下限值 When N is turned on - The first valve and its corresponding cyclone, 1≤N - <N; When the total water inlet pressure WP1 is greater than P 上限值 When N is turned on + The first valve and its corresponding cyclone, N + >N and N + ≥3.

10. The method for controlling a low-solids-content sewage cyclone sand removal system according to claim 8, characterized in that: In step S200: All the second valves are set to a cyclical start-up sequence. When the start-up sequence of any second valve is reached and the second valve meets the opening sand discharge conditions, the second valve is opened to discharge the bottom flow sand. When the opening sand discharge reaches the predetermined sand discharge time T 排 Then the second valve is automatically closed; when the activation sequence of any second valve is in turn, if the second valve does not meet the opening and sand discharge conditions, the second valve will not be opened, and the activation sequence will be in turn to the next second valve; When any of the first valves is opened, the opening time of the first valve is recorded. When the first valve is closed, the timing is stopped and the record is not reset. When the first valve is opened again, the timing is continued until the cumulative opening time t1 ≥ the preset time T0, and the corresponding second valve meets the opening sand discharge condition. When the second valve that meets the opening sand discharge condition takes turns to the start sequence and opens to discharge sand, the corresponding cumulative opening time t1 of the first valve is reset and the next round of timing begins again. When the second valve is opened to discharge underflow sand, the corresponding first valve is in a closed state.

11. The method for controlling a low-solids-content sewage cyclone sand removal system according to claim 8 or 10, characterized in that: In step S300: the multiple process links of the operation cycle include the initialization link, water intake link, sedimentation link, drainage link and sand separation link set in sequence; the second valve is opened to discharge sand only in the water intake link of each operation cycle, and then the sand-water separator performs the subsequent processing. The next operation cycle can only start after one operation cycle is completed; if the previous operation cycle has not ended, and the next second valve has met the conditions for opening and discharging sand, the next second valve will be delayed and wait.

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