Sedimentation tank sludge discharge monitoring control system and method

Abstract

The present invention relates to the field of control technology, and more specifically to a sedimentation tank sludge discharge monitoring and control system and method, which aims to improve water treatment efficiency. The monitoring and control system proposed in the present invention includes: an instrument detection module and a logic control module. The instrument detection module includes: a water inlet flowmeter for the raw water inlet, a turbidity meter for the clean water outlet, a center tube pressure transmitter, a cone bucket pressure differential transmitter, a sludge discharge flowmeter, and a sludge discharge pressure differential transmitter; the logic control module is used to automatically control the operation of the swirl sludge discharge system and the cone bucket fluidization system of the sedimentation tank according to the output parameters of each instrument in the instrument detection module. The present invention reduces the dependence on the work experience of technicians and improves water treatment efficiency.

Description

Technical Field

[0001] The present invention relates to the field of control technology, and in particular to a sedimentation tank sludge discharge monitoring control system and method. Background Art

[0002] A sedimentation tank is a device that uses sedimentation to remove suspended matter in water and purify water quality. It is widely used in the field of water treatment. Its working principle is to use the natural sedimentation or coagulation sedimentation of water to remove suspended matter in water.

[0003] There are two main types of existing sedimentation tank sludge discharge control methods. One is that technical personnel observe the operation of the sedimentation tank and judge whether the sedimentation tank needs to perform sludge discharge operations based on long-term work experience; the other is to achieve sludge discharge by setting a fixed sludge discharge cycle. This method requires determining the optimal sludge discharge cycle based on actual experience. The process of determining the sludge discharge cycle is difficult and often requires trial and error based on operating experience.

[0004] Both of the above methods have the problems of strong subjectivity, high requirements for work experience and low water treatment efficiency. Summary of the Invention

[0005] In order to solve the above problems in the prior art, the present invention proposes a sedimentation tank sludge discharge monitoring control system and method, which reduces the dependence on the work experience of technicians and improves water treatment efficiency.

[0006] In one aspect of the present invention, a sedimentation tank sludge discharge monitoring and control system is provided, wherein the monitoring and control system comprises: an instrument detection module and a logic control module;

[0007] The instrument detection module comprises: an inlet flowmeter (401F) provided at the raw water inlet (103) of the sedimentation tank, a turbidity meter (402) provided at the clean water outlet (104) of the sedimentation tank, a central tube pressure transmitter (401P) provided on the inner side of the bottom of the central tube (102) of the sedimentation tank, cone hopper differential pressure transmitters (403DP) located at the starting end and the discharge end of the cone hopper (106) of the sedimentation tank on both sides, and a sludge discharge flowmeter (404F) and a sludge discharge differential pressure transmitter (404DP) provided after the outlet of the sludge delivery pump (202); wherein the central tube pressure transmitter (401P), the cone hopper differential pressure transmitter (403DP), and the sludge discharge differential pressure transmitter (404DP) are all diaphragm sensors, so as to minimize the risk of solid matter in the slurry clogging the drainage pipe;

[0008] The logic control module is used to control the operation of the cyclone mud discharge system and the cone bucket fluidization system of the sedimentation tank according to the output parameters of each instrument in the instrument detection module;

[0009] The sedimentation tank comprises: a tank body (101), the central tube (102), the cone bucket (106) arranged below the tank body, a mud bucket (107) arranged below the cone bucket, the swirl mud discharge system and the cone bucket fluidization system.

[0010] Preferably, the cyclone mud discharge system comprises: a cyclone mud discharge port (201) tangentially arranged at the bottom of the mud hopper (107), a sludge delivery pump (202), and a sludge delivery inlet valve (203) and a sludge delivery outlet valve (204) for controlling the entry and exit of sludge into and out of the sludge delivery pump (202);

[0011] The cone bucket fluidization system comprises: a cone bucket fluidization outlet (301) arranged at the bottom of the cone bucket (106) in a tangential manner, a cone bucket fluidization inlet (302) arranged at the top of the cone bucket (106) in a swirl tangential manner, a sludge circulation pump (303), and a sludge fluidization inlet valve (304) and a sludge fluidization outlet valve (305) for controlling the entry and exit of sludge from the sludge circulation pump (303);

[0012] The logic control module includes: a startup control unit and a shutdown control unit;

[0013] The power-on control unit comprises:

[0014] The first startup subunit is configured to: start inputting the slurry to be treated into the central cylinder (102), open the sludge fluidization inlet valve (304) and the sludge fluidization outlet valve (305), start the sludge circulation pump (303), and thus complete the startup of the cone hopper fluidization system;

[0015] The second startup subunit is configured to: detect the pressure difference P of the cone bucket (106) 锥 , when P 锥 >ρ 目标 *g*H 锥 When the sludge delivery inlet valve (203) and the sludge delivery outlet valve (204) are opened, the sludge delivery pump (202) is started, thereby completing the opening of the cyclone sludge discharge system;

[0016] The shutdown control unit includes:

[0017] The first shutdown subunit is configured to: stop inputting the slurry to be treated into the central cylinder (102), and keep the sludge delivery pump (202) continuously performing the sludge discharge operation at the frequency before shutdown;

[0018] The second shutdown subunit is configured to: stop the sludge circulation pump (303), close the sludge fluidization inlet valve (304) and the sludge fluidization outlet valve (305), thereby completing the shutdown of the cone hopper fluidization system;

[0019] The third shutdown subunit is configured to: wait for P 锥 <ρ L *g*H 锥 When the sludge in the cone bucket is completely discharged, the sludge delivery pump (202) is stopped, and the sludge delivery inlet valve (203) and the sludge delivery outlet valve (204) are closed, thereby completing the shutdown of the cyclone sludge discharge system.

[0020] Preferably, the connection between the mud hopper (107) and the cone hopper (106) is smoothly transitioned; the sludge flows out from the sludge discharge port (201) and is discharged via the sludge delivery pump (202); the streamline formed by the sludge discharge sludge gradually rises along the side wall of the mud hopper (107), and continues to rise along the side wall after entering the cone hopper (106), thereby forming a disturbance effect on the sludge on the side wall of the cone hopper (106), making it difficult for the sludge to accumulate;

[0021] The sludge in the cone bucket (106) flows out from the cone bucket fluidization outlet (301) and is transported to the cone bucket fluidization inlet (302) via the sludge circulation pump (303) and enters the cone bucket (106), so that the sludge in the cone bucket (106) is fully fluidized without affecting the smoothness of the sludge discharge by the cyclone; the cone bucket fluidization outlet (301) and the cone bucket fluidization inlet (302) are both arranged outside the sedimentation area of the sedimentation particles, without affecting the overall sedimentation effect.

[0022] Preferably, the logic control module further comprises: a sludge flow regulating unit;

[0023] The sludge flow regulating unit comprises:

[0024] The mud discharge flow calculation subunit is configured to calculate the basic mud discharge flow and the additional mud discharge flow respectively, and then calculate the target mud discharge flow that needs to be controlled:

[0025]

[0026] Q 排 =Q 排1 +Q 排2 ;

[0027] Among them, Q 排1 , Q 排2 and Q 排 are the basic mud discharge flow, the additional mud discharge flow and the target mud discharge flow respectively; Q 进H is the flow rate of the slurry to be treated entering the sedimentation tank; 筒 、H 锥 and H 排 The distance between the two measuring terminals of the center tube pressure transmitter (401P), the cone bucket differential pressure transmitter (403DP) and the mud discharge differential pressure transmitter (404DP); P 进 、P 锥 and P 排 are the measured values of the central tube pressure transmitter (401P), the cone bucket differential pressure transmitter (403DP) and the mud discharge differential pressure transmitter (404DP), respectively; ρ L and ρ 目标 are the liquid phase density of the slurry to be treated and the slurry density under the control target concentration, both of which are preset values; g is the acceleration of gravity; t 调节 is the system regulation period; V 锥 is the volume of the cone bucket (106);

[0028] The frequency conversion control subunit is configured to perform frequency conversion control on the sludge delivery pump (202) according to the target sludge discharge flow rate, so that the total solid content of the discharged sludge is equal to the total solid content of the slurry entering the sedimentation tank, thereby ensuring the normal operation of the sedimentation tank.

[0029] Preferably, the sedimentation tank further comprises: a backwash system;

[0030] The backwash system comprises: a backwash device and a backwash water inlet (501) arranged on the cone bucket (106); the backwash water inlet (501) is arranged in the middle position between the cone bucket fluidization inlet (302) and the cone bucket fluidization outlet (301) in both the height direction and the circumference direction, so as to be located at the interface most prone to mud accumulation;

[0031] The logic control module further includes: a backwash adjustment unit;

[0032] The backwash adjustment sheet includes:

[0033] The backwash opening subunit is configured to: determine whether the P is satisfied according to the output of the cone bucket pressure differential transmitter (403DP) 锥 >ρ 积泥 *g*H 锥 If yes, it indicates that sludge is accumulated in the cone bucket (106), and the cone bucket backwashing system is turned on to backwash the cone bucket sludge;

[0034] The backwash closing subunit is configured to: determine whether the P is satisfied according to the output of the cone bucket pressure differential transmitter (403DP) 锥 ≤ρ 目标 *g*H 锥If so, the cone bucket backwash system is turned off and the flushing is stopped;

[0035] Among them, ρ 积泥 It is the density of mud in cone bucket, which is the preset value.

[0036] Preferably, the logic control module further comprises: a clear water mixing prediction unit;

[0037] The clean water mixing prediction unit includes:

[0038] The absolute dry sludge escape amount calculation subunit is configured to calculate and detect the absolute dry sludge escape amount according to the following formula:

[0039] S 逃 ={∫0 ti [(S 进 )-(S 排 )]d(t)}-S 锥 ;

[0040] Wherein, ti is the cumulative operating time, and the slurry feeding time of the sedimentation tank is 0;

[0041] The mixed risk judgment subunit is configured to: judge whether S 逃 >0; If so, it indicates that solid matter has entered the clear water area, and there is a risk of mixing in the sedimentation tank. The dosage of the front-end coagulation operation unit should be adjusted;

[0042] The effluent turbidity judgment subunit is configured to: judge whether the effluent turbidity of the sedimentation tank is qualified; if so, continue to operate; otherwise, return the water flowing out of the sedimentation tank to the front-end coagulation operation unit for further treatment.

[0043] Preferably, the logic control module further comprises: an indicator monitoring unit;

[0044] The indicator monitoring unit includes:

[0045] The first monitoring subunit is configured to calculate the mass percentage concentration of the inlet slurry according to the following formula:

[0046] MS 进 =((g*H 筒 ) / P 进 -1 / ρ L ) / (1 / ρ s -1 / ρ L );

[0047] The second monitoring subunit is configured to calculate the mass percentage concentration of the cone hopper slurry according to the following formula:

[0048] MS 锥 =((g*H 锥 ) / P 锥-1 / ρ L ) / (1 / ρ s -1 / ρ L );

[0049] The third monitoring subunit is configured to calculate the mass percentage concentration of the mud slurry according to the following formula:

[0050] MS 排 =((g*H 排 ) / P 排 -1 / ρ L ) / (1 / ρ s -1 / ρ L )

[0051] The fourth monitoring subunit is configured to calculate the instantaneous content of the total solid matter in the slurry according to the following formula:

[0052] S 进 =Q 进 *(1-P 进 / (ρ L *g*H 筒 )) / (1 / ρ s -1 / ρ L )

[0053] The fifth monitoring subunit is configured to calculate the instantaneous content of total solid matter in the sludge according to the following formula:

[0054] S 排 =Q 排 *(1-P 排 / (ρ L *g*H 排 )) / (1 / ρ s -1 / ρ L )

[0055] The sixth monitoring subunit is configured to calculate the total solid matter content of the cone hopper according to the following formula:

[0056] S 锥 =V 锥 *(1-P 锥 / (ρ L *g*H 锥 )) / (1 / ρ s -1 / ρ L )

[0057] Among them, ρ s is the solid phase density of the slurry, the preset value.

[0058] Preferably, the transition radius of the connection between the mud bucket (107) and the cone bucket (106) is about R250mm;

[0059] The angle of the mud bucket (107) is 5 to 10 degrees;

[0060] There is one swirl mud discharge port (201) and one cone fluidization outlet (301);

[0061] There are four conical bucket fluidization inlets (302), which are evenly distributed along the circumference of the conical bucket (106);

[0062] There are four backwash water inlets (501), which are evenly distributed along the circumference of the cone bucket (106).

[0063] Another aspect of the present invention provides a sedimentation tank sludge discharge monitoring and control method. The method is based on the sedimentation tank sludge discharge monitoring and control system described above, and the method comprises:

[0064] If a power-on command is received, the first power-on sub-unit and the second power-on sub-unit are called in sequence, thereby completing the startup of the cone bucket fluidization system and the cyclone mud discharge system;

[0065] After startup, the sludge flow regulating unit, the backwash regulating unit and the clear water mixing prediction unit are called to run in parallel, thereby dynamically adjusting the sludge flow, preventing sludge accumulation in the cone bucket, and promptly handling the clear water mixing phenomenon;

[0066] If a shutdown command is received, the first shutdown subunit, the second shutdown subunit and the third shutdown subunit are called in sequence to complete the shutdown of the cone bucket fluidization system and the cyclone mud discharge system.

[0067] Preferably, the method further comprises:

[0068] Call each subunit in the indicator monitoring unit to calculate the mass percentage concentration of the inlet slurry, the mass percentage concentration of the cone bucket slurry, the mass percentage concentration of the mud discharge slurry, the instantaneous content of the total solid matter in the inlet slurry, the instantaneous content of the total solid matter in the mud discharge, and the total solid matter content in the cone bucket.

[0069] The present invention has the following beneficial effects:

[0070] The sedimentation tank sludge discharge monitoring and control system proposed by the present invention utilizes an instrument detection module to monitor in real time the raw water inlet flow, the clean water outlet flow, the sludge discharge flow, the center tube pressure difference, the cone bucket pressure difference, and the sludge discharge pressure difference. The logic control module automatically controls the operation of the cyclone sludge discharge system and the cone bucket fluidization system of the sedimentation tank according to the output parameters of the instrument detection module. This can effectively prevent sludge accumulation in the cone bucket without relying on the work experience of technical personnel, thereby improving sewage treatment efficiency.

[0071] The startup control unit and shutdown control unit in the logic control module control the sludge circulation pump, sludge conveying pump and related valves in an orderly manner according to the output parameters of the instrument detection module, realizing automatic start / stop control of the sedimentation tank cone bucket fluidization system and the sludge conveying system.

[0072] The sludge flow regulation unit calculates the current target sludge discharge flow in real time according to the output parameters of the instrument detection module, and performs frequency conversion control on the sludge delivery pump so that the total solid content of the discharged sludge is equal to the total solid content of the slurry entering the sedimentation tank, ensuring the normal and stable operation of the sedimentation tank.

[0073] The backwash adjustment unit determines the sludge accumulation in the cone bucket according to the output parameters of the instrument detection module, and thus opens / closes the cone bucket backwash system in time, which not only avoids the occurrence of sludge blockage, but also avoids the inefficiency caused by excessive flushing.

[0074] The clean water mixing prediction unit calculates the escape amount of absolute dry sludge based on the output parameters of the instrument detection module, determines whether solid matter has entered the clean water area, and then decides whether to adjust the dosage of the front-end coagulation operation unit, realizing dynamic adjustment of the dosage according to the influent water quality and water volume; the judgment unit also determines the turbidity of the effluent from the sedimentation tank, and then decides whether to return the outflowing water to the front-end coagulation operation unit for further treatment, thereby ensuring the quality of the final effluent.

[0075] In addition, the indicator detection unit can update some key water treatment indicators in real time, so that technical personnel can understand the operation status of the sedimentation tank in a timely manner.

[0076] In short, the above instrument detection module and logic control module cooperate with each other to realize the automatic monitoring and control of the sedimentation tank operation, which not only avoids the blockage of the mud discharge channel, but also ensures the quality of the effluent, greatly reduces the dependence on the experience of technical personnel, and effectively improves the efficiency of water treatment. BRIEF DESCRIPTION OF THE DRAWINGS

[0077] Figure 1 This is a schematic diagram of the main components of a sedimentation tank and its sludge discharge monitoring and control system according to an embodiment of the present invention;

[0078] Figure 2 Schematic diagram of a swirl mud discharge bucket in an embodiment of the present invention;

[0079] Figure 3 Schematic diagram of a cone-bucket fluidization system according to an embodiment of the present invention;

[0080] Figure 4 Schematic diagram of a backwash system in an embodiment of the present invention. DETAILED DESCRIPTION

[0081] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0082] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0083] It should be noted that, in the description of the present invention, the terms "first" and "second" are merely for the convenience of description, and do not indicate or imply the relative importance of the devices, elements or parameters, and therefore should not be understood as limiting the present invention. In addition, the term "and / or" in the present invention is merely a description of the association relationship between associated objects, indicating that three relationships may exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this document, unless otherwise specified, generally indicates that the associated objects are in an "or" relationship.

[0084] Figure 1 This is a schematic diagram of the main components of the sedimentation tank and its sludge discharge monitoring and control system in the embodiment of the present invention. The monitoring and control system of this embodiment includes: an instrument detection module and a logic control module. Figure 1 As shown, the instrument detection module includes: an inlet flow meter 401F arranged at the raw water inlet 103 of the sedimentation tank, a turbidity meter 402 arranged at the clean water outlet 104 of the sedimentation tank, a central tube pressure transmitter 401P arranged on the inner side of the bottom of the central tube 102 of the sedimentation tank, cone bucket differential pressure transmitters 403DP located at the starting end and discharge end of the cone bucket 106 of the sedimentation tank on both sides, and a sludge discharge flow meter 404F and a sludge discharge differential pressure transmitter 404DP arranged after the outlet of the sludge conveying pump 202; among them, the central tube pressure transmitter (401P), the cone bucket differential pressure transmitter 403DP, and the sludge discharge differential pressure transmitter 404DP are all diaphragm sensors to minimize the risk of solid matter in the slurry clogging the drainage pipe.

[0085] In this embodiment, the logic control module (not shown in the figure) is used to control the operation of the cyclone mud discharge system and the cone bucket fluidization system of the sedimentation tank according to the output parameters of each instrument in the instrument detection module.

[0086] Continue to read Figure 1In this embodiment, the sedimentation tank includes: a tank body 101, a central tube 102, a raw water inlet 103 disposed above the central tube 102, a clean water outlet 104 disposed at the upper portion of the tank body 101, an inclined plate 105, a cone hopper 106 disposed below the tank body, and a mud hopper 107 disposed below the cone hopper 106. The cone hopper 106 and the mud hopper 107 constitute a swirl mud hopper.

[0087] In the existing technology, the bottom of the sedimentation tank is a funnel-shaped cone (with or without a scraper), and the sludge settles, concentrates, and accumulates at the bottom of the tank. The sludge discharge method commonly used in sedimentation tanks is to install a sludge discharge pipe at the bottom or top of the tank, and connect a sludge discharge valve to the external connection of the sludge discharge pipe to control the sludge discharge. However, in actual operation, it often happens that during sludge discharge, the sludge in the center of the sludge sedimentation area at the bottom of the tank will quickly collapse, forming a funnel-shaped cavity. As the flow rate increases, the surrounding sludge has not yet been discharged, and the upper layer of clear water has already entered the sludge discharge port straightly with the sludge outlet as the center. As the mud and water mixed flow quickly forms, water becomes the main discharge body, while a large amount of sludge in the surrounding area is still attached to the slope of the bottom of the tank, making it difficult to discharge.

[0088] Figure 2 Schematic diagram of the swirl mud bucket in the embodiment of the present invention. Figure 2 As shown, the connection between the mud hopper 107 and the cone hopper 106 is smooth. Sludge flows out of the sludge discharge port 201 and is discharged via the sludge delivery pump 202. The streamlines formed by the sludge discharge gradually rise along the sidewalls of the mud hopper 107 and continue to rise along the sidewalls after entering the cone hopper 106, thereby disturbing the sludge on the sidewalls of the cone hopper 106 and preventing sludge accumulation.

[0089] In this embodiment, the swirl mud discharge system includes: a swirl mud discharge port 201 arranged in a tangential manner at the bottom of the mud hopper 107, a sludge conveying pump 202, and a sludge conveying inlet valve 203 and a sludge conveying outlet valve 204 for controlling the entry and exit of sludge into and out of the sludge conveying pump 202.

[0090] Figure 3 Schematic diagram of the cone-bucket fluidization system in the embodiment of the present invention. Figure 3 As shown, the cone bucket fluidization system includes: a cone bucket fluidization outlet 301 arranged in a tangential form at the bottom of the cone bucket 106, a cone bucket fluidization inlet 302 arranged in a swirl tangential form at the top of the cone bucket 106, a sludge circulation pump 303, and a sludge fluidization inlet valve 304 and a sludge fluidization outlet valve 305 for controlling the sludge entering and flowing out of the sludge circulation pump.

[0091] The sludge in the cone bucket 106 flows out from the cone bucket fluidization outlet 301 and is transported to the cone bucket fluidization inlet 302 through the sludge circulation pump 303 and then enters the cone bucket 106, so that the sludge in the cone bucket 106 is fully fluidized without affecting the smoothness of the sludge discharge by the swirl flow; the cone bucket fluidization outlet 301 and the cone bucket fluidization inlet 302 are both set in the sedimentation area ( Figure 1 Except for the triangular area below the central tube, it does not affect the overall sedimentation effect.

[0092] Continue to read Figure 1 The sludge conveying pump 202 and the sludge circulation pump 303 in this embodiment can also be used interchangeably. Specifically, first close all the valves marked "on" in the figure (203, 204, 304 and 305), and then open all the valves marked "OFF" (601, 602, 603 and 604). In this way, the sludge conveying pump 202 will be cut into the cone bucket fluidization system, and the sludge circulation pump 303 will be cut into the sludge conveying system.

[0093] In this embodiment, the logic control module may include: a startup control unit and a shutdown control unit. Since the logic control module is basically completed by a program, the units mentioned below are not described in detail. Figure 1 Shown in.

[0094] The power-on control unit of this embodiment includes: a first power-on sub-unit and a second power-on sub-unit.

[0095] Continue to read Figure 1 The first startup subunit is configured to: start the input of the slurry to be treated into the central tube 102, open the sludge fluidization inlet valve 304 and the sludge fluidization outlet valve 305, start the sludge circulation pump 303, and thus complete the opening of the cone bucket fluidization system; the second startup subunit is configured to: detect the pressure difference P of the cone bucket 106 锥 , when P 锥 >ρ 目标 *g*H 锥 When the sludge conveying inlet valve 203 and the sludge conveying outlet valve 204 are opened, the sludge conveying pump 202 is started, thereby completing the opening of the cyclone sludge discharge system.

[0096] The shutdown control unit of this embodiment includes: a first shutdown sub-unit, a second shutdown sub-unit and a third shutdown sub-unit.

[0097] Continue to read Figure 1The first shutdown subunit is configured to: stop inputting the slurry to be treated into the central tube 102, and keep the sludge delivery pump 202 continuously discharging sludge at the frequency before shutdown; the second shutdown subunit is configured to: stop the sludge circulation pump 303, close the sludge fluidization inlet valve 304 and the sludge fluidization outlet valve 305, thereby completing the shutdown of the cone bucket fluidization system; the third shutdown subunit is configured to: wait for P 锥 <ρ L *g*H 锥 When the sludge in the cone bucket is completely discharged, the sludge delivery pump 202 is stopped, and the sludge delivery inlet valve 203 and the sludge delivery outlet valve 204 are closed, thereby completing the shutdown of the cyclone sludge discharge system.

[0098] In an optional embodiment, the logic control module may further include: a sludge flow regulating unit.

[0099] The sludge flow regulating unit includes: a sludge flow calculation subunit and a frequency conversion control subunit.

[0100] The mud discharge flow calculation subunit is configured to calculate the mud discharge basic flow and mud discharge additional flow according to the following formulas (1), (2) and (3), respectively, and then calculate the target mud discharge flow that needs to be controlled:

[0101]

[0102] Q 排 = Q 排1 + Q 排2 (3)

[0103] Among them, Q 排1 , Q 排2 and Q 排 are the basic mud discharge flow, additional mud discharge flow and target mud discharge flow respectively; Q 进 is the flow rate of the slurry to be treated entering the sedimentation tank; H 筒 、H 锥 and H 排 The distance between the two measuring terminals of the center tube pressure transmitter 401P, cone bucket differential pressure transmitter 403DP and mud discharge differential pressure transmitter 404DP respectively; P 进 、P 锥 and P 排 are the measured values of the center tube pressure transmitter 401P, cone bucket differential pressure transmitter 403DP and mud discharge differential pressure transmitter 404DP respectively; ρ L and ρ 目标 are the liquid phase density of the slurry to be treated and the slurry density under the control target concentration, both of which are preset values; g is the acceleration of gravity; t 调节 is the system regulation period; V 锥The volume of the cone bucket 106; the frequency control subunit is configured to perform frequency control on the sludge delivery pump 202 according to the target sludge flow rate, so that the total solid content of the sludge is equal to the total solid content of the slurry entering the sedimentation tank, to ensure the normal operation of the sedimentation tank.

[0104] In another optional embodiment, the sedimentation tank may further include: a backwash system.

[0105] Figure 4 Schematic diagram of the backwash system in the embodiment of the present invention. Figure 4 As shown, the backwash system includes: a backwash device (not shown in the figure) and a backwash water inlet 501 arranged on the cone bucket 106; the backwash water inlet 501 is arranged in the middle position between the cone bucket fluidization inlet 302 and the cone bucket fluidization outlet 301 in the height direction and the circumferential direction, so as to be located on the interface most prone to mud accumulation.

[0106] In this embodiment, the logic control module further includes: a backwash adjustment unit.

[0107] The backwash adjustment sheet includes: a backwash opening subunit and a backwash closing subunit.

[0108] Among them, the backwash opening subunit is configured as follows: according to the output of the cone bucket pressure differential transmitter 403DP, it is determined whether P is satisfied. 锥 >ρ 积泥 *g*H 锥 If so, it indicates that the sludge in the cone bucket 106 is accumulated, and the backwashing device is started to feed flushing water to the backwashing water inlet 501, thereby opening the cone bucket backwashing system to backwash the cone bucket sludge; the backwash closing subunit is configured as follows: according to the output of the cone bucket pressure differential transmitter 403DP, it is determined whether P is satisfied 锥 ≤ρ 目标 *g*H 锥 If yes, turn off the cone bucket backwash system and stop flushing. 积泥 It is the density of mud in cone bucket, which is the preset value.

[0109] In another optional embodiment, the logic control module may further include: a clean water mixing prediction unit.

[0110] The clean water mixing prediction unit includes: a dry sludge escape amount calculation subunit, a mixing risk judgment subunit and a effluent turbidity judgment subunit.

[0111] The absolute dry sludge escape amount calculation subunit is configured to calculate and detect the absolute dry sludge escape amount according to formula (4):

[0112] S 逃 ={∫0 ti [(S 进 )-(S 排 )]d(t)}-S锥 (4)

[0113] Wherein, ti is the cumulative operating time, and the time when the slurry is fed into the sedimentation tank is 0.

[0114] The configuration of the mixed risk judgment subunit is: to judge whether S 逃 >0; If so, it indicates that solid matter has entered the clear water area ( Figure 1 The area above the middle inclined plate) indicates that there is a risk of mixing in the sedimentation tank, and the dosage of the front-end coagulation operation unit is adjusted; the effluent turbidity judgment subunit is configured to: judge whether the effluent turbidity of the sedimentation tank is qualified; if so, continue to operate; otherwise, return the water flowing out of the sedimentation tank to the front-end coagulation operation unit for further treatment.

[0115] In another optional embodiment, the logic control module may further include an indicator monitoring unit, the output of which may be displayed on a host computer screen of the logic control program.

[0116] The indicator monitoring unit includes: a first monitoring subunit, a second monitoring subunit, a third monitoring subunit, a fourth monitoring subunit, a fifth monitoring subunit, and a sixth monitoring subunit.

[0117] The first monitoring subunit is configured to calculate the mass percentage concentration of the inlet slurry according to formula (5):

[0118] MS 进 =((g*H 筒 ) / P 进 -1 / ρ L ) / (1 / ρ s -1 / ρ L ) (5)

[0119] The second monitoring subunit is configured to calculate the mass percentage concentration of the cone hopper slurry according to formula (6):

[0120] MS 锥 =((g*H 锥 ) / P 锥 -1 / ρ L ) / (1 / ρ s -1 / ρ L ) (6)

[0121] The third monitoring subunit is configured to calculate the mass percentage concentration of the mud slurry according to formula (7):

[0122] MS 排 =((g*H 排 ) / P 排 -1 / ρ L ) / (1 / ρ s -1 / ρ L ) (7)

[0123] The fourth monitoring subunit is configured to calculate the instantaneous content of total solid matter in the slurry according to formula (8):

[0124] S 进 =Q 进 *(1-P 进 / (ρ L *g*H 筒 )) / (1 / ρ s -1 / ρ L ) (8)

[0125] The fifth monitoring subunit is configured to calculate the instantaneous content of total solid matter in the sludge according to formula (9):

[0126] S 排 =Q 排 *(1-P 排 / (ρ L *g*H 排 )) / (1 / ρ s -1 / ρ L ) (9)

[0127] The sixth monitoring subunit is configured to calculate the total solid matter content of the cone hopper according to formula (10):

[0128] S 锥 =V 锥 *(1-P 锥 / (ρ L *g*H 锥 )) / (1 / ρ s -1 / ρ L )(10)

[0129] Among them, ρ s is the solid phase density of the slurry, the preset value.

[0130] Optionally, in the above embodiment, the transition radius of the connection between the mud bucket 107 and the cone bucket 106 is approximately R250mm; the angle of the mud bucket 106 is 5 to 10°; there are 1 swirl mud discharge port 201 and 1 cone bucket fluidization outlet 301; there are 4 cone bucket fluidization inlets 302, and they are evenly distributed along the circumference of the cone bucket 106; there are 4 wash water inlets 501, and they are evenly distributed along the circumference of the cone bucket 106.

[0131] The present invention also provides an embodiment of a sedimentation tank sludge discharge monitoring and control method. The method of this embodiment is based on the sedimentation tank sludge discharge monitoring and control system described above, and includes steps S10-S30:

[0132] Step S10: If a power-on instruction is received, the first power-on sub-unit and the second power-on sub-unit are called in sequence, thereby completing the startup of the cone bucket fluidization system and the cyclone mud discharge system.

[0133] In step S20, the sludge flow regulating unit, the backwash regulating unit and the clear water mixing prediction unit are called to run in parallel, thereby dynamically regulating the sludge flow, preventing sludge accumulation in the cone bucket, and promptly handling the clear water mixing phenomenon.

[0134] Step S30: If a shutdown command is received, the first shutdown sub-unit, the second shutdown sub-unit and the third shutdown sub-unit are called in sequence to complete the shutdown of the cone bucket fluidization system and the cyclone mud discharge system.

[0135] In an optional embodiment, step S20 may further include:

[0136] Call each sub-unit in the indicator monitoring unit to calculate the mass percentage concentration of the inlet slurry, the mass percentage concentration of the cone bucket slurry, the mass percentage concentration of the discharge mud slurry, the instantaneous content of the total solid matter in the inlet slurry, the instantaneous content of the total solid matter in the discharge mud, and the total solid matter content in the cone bucket.

[0137] The following takes desulfurization wastewater in the field of desulfurization wastewater treatment as an example to introduce in detail the sedimentation tank sludge discharge monitoring and control method of the present invention.

[0138] First, determine the relevant parameters of the slurry to be treated:

[0139] (1) Detection of slurry liquid phase density ρ L ,ρ L =1027kg / m 3 ;

[0140] (2) Detection of slurry solid phase density ρ S ,ρ S =2299kg / m 3 ;

[0141] (3) The formula for the mass percentage concentration of slurry MS is shown in formula (11):

[0142] MS=(1 / ρ-1 / ρ L ) / (1 / ρ S -1 / ρ L ) (11)

[0143] Secondly, determine the relevant parameters of the mud slurry:

[0144] (1) Determine the target mud density ρ 目标 :Under normal circumstances, this indicator is determined by the subsequent process requirements, but it is usually required to set the slurry mass percentage MS. Taking desulfurization wastewater treatment as an example, it is usually required to set MS = 20%. According to formula (11), ρ 目标 =1155kg / m 3 .

[0145] (2) Determine the density of the hopper mud ρ 积泥 :The present invention has set up a cyclone sludge discharge system and a cone bucket fluidization system, which greatly improves the mass percentage MS of sludge deposition. Taking desulfurization wastewater treatment as an example, MS = 30% is usually required. According to formula (11), ρ 积泥 =1231kg / m 3 .

[0146] The above is the preparation stage before the initial operation of the sedimentation tank. At the same time, the above parameters can also be regularly calibrated to obtain better operating results.

[0147] The specific steps of the sedimentation tank operation stage are as follows:

[0148] The first step is the startup procedure, and the sedimentation tank begins to flow the slurry to be treated after the coagulation reaction.

[0149] The slurry flows through the central cylinder 102 and enters the cone bucket 106. The sludge fluidization inlet valve 304 and the sludge fluidization outlet valve 305 are opened, and the sludge circulation pump 303 is started at full frequency. The cone bucket fluidization system is started.

[0150] At the same time, the sedimentation tank P 锥 , when P 锥 >ρ 目标 *g*H 锥 At this time, the sludge conveying inlet valve 203 and the sludge conveying outlet valve 204 are opened, the sludge conveying pump 202 is started, and the sludge conveying system is completely opened.

[0151] At this point, the sedimentation tank is started up and the system is operating normally: it enters the control and adjustment stage.

[0152] The adjustment phase is as follows:

[0153] The sludge discharge flow calculation subunit is called to calculate the target sludge discharge flow rate, and the frequency conversion control subunit is called to control the speed of the sludge conveying pump so that the actual sludge discharge flow rate is approximately equal to the target sludge discharge flow rate.

[0154] The backwash adjustment unit is used to monitor and adjust the mud accumulation in the cone bucket under extreme working conditions. Specifically: call the backwash start subunit to monitor P in real time. 锥 When the cone bucket is found to be sludge, the cone bucket backwash system is turned on to backwash the cone bucket sludge; the backwash shutdown subunit is called to continue monitoring P 锥 When the cone bucket mud is found to be relieved, the flushing is completed and the cone bucket backwash system is closed.

[0155] The clean water mixing prediction unit is used to predict whether the clean water effluent is at risk of mixing and to promptly adjust the dosage of the front-end coagulation operation unit. Specifically, it calls the absolute dry sludge escape calculation subunit to calculate the absolute dry sludge escape amount; calls the mixing risk judgment subunit to determine whether there is a risk of mixing and, if so, promptly adjusts the dosage of the front-end coagulation operation unit; calls the effluent turbidity judgment subunit to determine the effluent turbidity and, if the turbidity is unacceptable, returns the water to the front-end coagulation operation unit for further treatment.

[0156] When the system needs to be shut down, the first shutdown subunit, the second shutdown subunit and the third shutdown subunit are called in sequence to complete the shutdown of the cone bucket fluidization system and the cyclone mud discharge system.

[0157] Those skilled in the art should be able to appreciate that the method steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of electronic hardware and software, the composition and steps of each example have been generally described in terms of function in the above description. Whether these functions are performed in electronic hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art may use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0158] Thus far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is clearly not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art may make equivalent modifications or substitutions to the relevant technical features, and the technical solutions after such modifications or substitutions will fall within the scope of protection of the present invention.

Claims

1. A sedimentation tank sludge discharge monitoring and control system, characterized in that: The monitoring and control system includes: an instrument detection module and a logic control module; The instrument detection module comprises: an inlet flowmeter (401F) provided at the raw water inlet (103) of the sedimentation tank, a turbidity meter (402) provided at the clean water outlet (104) of the sedimentation tank, a central tube pressure transmitter (401P) provided on the inner side of the bottom of the central tube (102) of the sedimentation tank, cone hopper differential pressure transmitters (403DP) located at the starting end and the discharge end of the cone hopper (106) of the sedimentation tank on both sides, and a sludge discharge flowmeter (404F) and a sludge discharge differential pressure transmitter (404DP) provided after the outlet of the sludge delivery pump (202); wherein the central tube pressure transmitter (401P), the cone hopper differential pressure transmitter (403DP), and the sludge discharge differential pressure transmitter (404DP) are all diaphragm sensors, so as to minimize the risk of solid matter in the slurry clogging the drainage pipe; The logic control module is used to control the operation of the cyclone mud discharge system and the cone bucket fluidization system of the sedimentation tank according to the output parameters of each instrument in the instrument detection module; The sedimentation tank comprises: a tank body (101), the central tube (102), the cone bucket (106) arranged below the tank body, a mud bucket (107) arranged below the cone bucket, the swirl mud discharge system and the cone bucket fluidization system; The cyclone mud discharge system comprises: a cyclone mud discharge port (201) tangentially arranged at the bottom of the mud hopper (107), a sludge delivery pump (202), and a sludge delivery inlet valve (203) and a sludge delivery outlet valve (204) for controlling the entry and exit of sludge into and out of the sludge delivery pump (202); The connection between the mud hopper (107) and the cone hopper (106) is smoothly transitioned; the sludge flows out of the sludge discharge port (201) and is discharged via the sludge delivery pump (202); the streamline formed by the sludge discharge sludge gradually rises along the side wall of the mud hopper (107), and continues to rise along the side wall after entering the cone hopper (106), thereby forming a disturbance effect on the sludge on the side wall of the cone hopper (106), making it difficult for the sludge to accumulate; The logic control module further includes: a sludge flow regulating unit; The sludge flow regulating unit comprises: The mud discharge flow calculation subunit is configured to calculate the basic mud discharge flow and the additional mud discharge flow respectively, and then calculate the target mud discharge flow that needs to be controlled: Q 排 =Q 排1 +Q 排2 ; Among them, Q 排1 , Q 排2 and Q 排 are the basic mud discharge flow, the additional mud discharge flow and the target mud discharge flow respectively; Q 进 is the flow rate of the slurry to be treated entering the sedimentation tank; H 筒 、H 锥 and H 排 The distance between the two measuring terminals of the center tube pressure transmitter (401P), the cone bucket differential pressure transmitter (403DP) and the mud discharge differential pressure transmitter (404DP); P 进 、P 锥 and P 排 are the measured values of the central tube pressure transmitter (401P), the cone bucket differential pressure transmitter (403DP) and the mud discharge differential pressure transmitter (404DP), respectively; ρ L and ρ 目标 are the liquid phase density of the slurry to be treated and the slurry density under the control target concentration, both of which are preset values; g is the acceleration of gravity; t 调节 is the system regulation period; V 锥 is the volume of the cone bucket (106); The frequency conversion control subunit is configured to perform frequency conversion control on the sludge delivery pump (202) according to the target sludge discharge flow rate, so that the total solid content of the discharged sludge is equal to the total solid content of the slurry entering the sedimentation tank, thereby ensuring the normal operation of the sedimentation tank.

2. The sedimentation tank sludge discharge monitoring and control system according to claim 1 is characterized in that: The cone bucket fluidization system comprises: a cone bucket fluidization outlet (301) arranged at the bottom of the cone bucket (106) in a tangential manner, a cone bucket fluidization inlet (302) arranged at the top of the cone bucket (106) in a swirl tangential manner, a sludge circulation pump (303), and a sludge fluidization inlet valve (304) and a sludge fluidization outlet valve (305) for controlling the entry and exit of sludge from the sludge circulation pump (303); The logic control module includes: a startup control unit and a shutdown control unit; The power-on control unit comprises: The first startup subunit is configured to: start inputting the slurry to be treated into the central cylinder (102), open the sludge fluidization inlet valve (304) and the sludge fluidization outlet valve (305), start the sludge circulation pump (303), and thus complete the startup of the cone hopper fluidization system; The second startup subunit is configured to: detect the pressure difference P of the cone bucket (106) 锥 , when P 锥 >ρ 目标 *g*H 锥 When the sludge delivery inlet valve (203) and the sludge delivery outlet valve (204) are opened, the sludge delivery pump (202) is started, thereby completing the opening of the cyclone sludge discharge system; The shutdown control unit includes: The first shutdown subunit is configured to: stop inputting the slurry to be treated into the central cylinder (102), and keep the sludge delivery pump (202) continuously performing the sludge discharge operation at the frequency before shutdown; The second shutdown subunit is configured to: stop the sludge circulation pump (303), close the sludge fluidization inlet valve (304) and the sludge fluidization outlet valve (305), thereby completing the shutdown of the cone hopper fluidization system; The third shutdown subunit is configured to: wait for P 锥 <ρ L *g*H 锥 When the sludge in the cone bucket is completely discharged, the sludge delivery pump (202) is stopped, and the sludge delivery inlet valve (203) and the sludge delivery outlet valve (204) are closed, thereby completing the shutdown of the cyclone sludge discharge system.

3. The sedimentation tank sludge discharge monitoring and control system according to claim 2 is characterized in that: The sludge in the cone bucket (106) flows out from the cone bucket fluidization outlet (301) and is transported to the cone bucket fluidization inlet (302) via the sludge circulation pump (303) and enters the cone bucket (106), so that the sludge in the cone bucket (106) is fully fluidized without affecting the smoothness of the sludge discharge by the cyclone; the cone bucket fluidization outlet (301) and the cone bucket fluidization inlet (302) are both arranged outside the sedimentation area of the sedimentation particles, without affecting the overall sedimentation effect.

4. The sedimentation tank sludge discharge monitoring and control system according to claim 2, characterized in that: The sedimentation tank also includes: a backwash system; The backwash system comprises: a backwash device and a backwash water inlet (501) arranged on the cone bucket (106); the backwash water inlet (501) is arranged in the middle position between the cone bucket fluidization inlet (302) and the cone bucket fluidization outlet (301) in both the height direction and the circumference direction, so as to be located at the interface most prone to mud accumulation; The logic control module further includes: a backwash adjustment unit; The backwash adjustment sheet includes: The backwash opening subunit is configured to: determine whether the P is satisfied according to the output of the cone bucket pressure differential transmitter (403DP) 锥 >ρ 积泥 *g*H 锥 If yes, it indicates that sludge is accumulated in the cone bucket (106), and the backwash system is turned on to backwash the cone bucket sludge; The backwash closing subunit is configured to: determine whether the P is satisfied according to the output of the cone bucket pressure differential transmitter (403DP) 锥 ≤ρ 目标 *g*H 锥 If so, the backwash system is turned off and flushing is stopped; Among them, ρ 积泥 It is the density of mud in cone bucket, which is the preset value.

5. The sedimentation tank sludge discharge monitoring and control system according to claim 4, characterized in that: The logic control module further includes: a clear water mixing prediction unit; The clean water mixing prediction unit includes: The absolute dry sludge escape amount calculation subunit is configured to calculate and detect the absolute dry sludge escape amount according to the following formula: S 逃 ={∫0 ti [(S 进 )-(S 排 )]d(t)}-S 锥 Wherein, ti is the cumulative operating time, and the slurry feeding time of the sedimentation tank is 0; The mixed risk judgment subunit is configured to: judge whether S 逃 >0; If so, it indicates that solid matter has entered the clear water area, and there is a risk of mixing in the sedimentation tank. The dosage of the front-end coagulation operation unit should be adjusted; The effluent turbidity judgment subunit is configured to: judge whether the effluent turbidity of the sedimentation tank is qualified; if so, continue to operate; otherwise, return the water flowing out of the sedimentation tank to the front-end coagulation operation unit for further treatment.

6. The sedimentation tank sludge discharge monitoring and control system according to claim 5, characterized in that: The logic control module further includes: an indicator monitoring unit; The indicator monitoring unit includes: The first monitoring subunit is configured to calculate the mass percentage concentration of the inlet slurry according to the following formula: MS 进 =((g*H 筒 ) / P 进 -1 / p L ) / (1 / ρ s -1 / p L ); The second monitoring subunit is configured to calculate the mass percentage concentration of the cone hopper slurry according to the following formula: MS 锥 =((g*H 锥 ) / P 锥 -1 / p L ) / (1 / ρ s -1 / p L ); The third monitoring subunit is configured to calculate the mass percentage concentration of the mud slurry according to the following formula: MS 排 =((g*H 排 ) / P 排 -1 / p L ) / (1 / ρ s -1 / p L ); The fourth monitoring subunit is configured to calculate the instantaneous content of the total solid matter in the slurry according to the following formula: S 进 =Q 进 *(1-P 进 / (r L *g*H 筒 )) / (1 / p s -1 / p L ); The fifth monitoring subunit is configured to calculate the instantaneous content of total solid matter in the sludge according to the following formula: S 排 =Q 排 *(1-P 排 / (r L *g*H 排 )) / (1 / p s -1 / p L ); The sixth monitoring subunit is configured to calculate the total solid matter content of the cone hopper according to the following formula: S 锥 =V 锥 *(1-P 锥 / (r L *g*H 锥 )) / (1 / p s -1 / p L ); Among them, ρ s is the solid phase density of the slurry, the preset value.

7. The sedimentation tank sludge discharge monitoring and control system according to claim 6, characterized in that: The transition radius of the connection between the mud bucket (107) and the cone bucket (106) is R250mm; The angle of the mud bucket (107) is 5 to 10 degrees; There is one swirl mud discharge port (201) and one cone fluidization outlet (301); There are four conical bucket fluidization inlets (302), which are evenly distributed along the circumference of the conical bucket (106); There are four backwash water inlets (501), which are evenly distributed along the circumference of the cone bucket (106).

8. A sedimentation tank sludge discharge monitoring and control method, characterized in that: The method is based on the sedimentation tank sludge discharge monitoring and control system according to any one of claims 6-7, and the method comprises: If a power-on command is received, the first power-on sub-unit and the second power-on sub-unit are called in sequence, thereby completing the startup of the cone bucket fluidization system and the cyclone mud discharge system; After startup, the sludge flow regulating unit, the backwash regulating unit and the clear water mixing prediction unit are called to run in parallel, thereby dynamically adjusting the sludge flow, preventing sludge accumulation in the cone bucket, and promptly handling the clear water mixing phenomenon; If a shutdown command is received, the first shutdown subunit, the second shutdown subunit and the third shutdown subunit are called in sequence to complete the shutdown of the cone bucket fluidization system and the cyclone mud discharge system.

9. The sedimentation tank sludge discharge monitoring and control method according to claim 8, characterized in that: The method further comprises: Call each subunit in the indicator monitoring unit to calculate the mass percentage concentration of the inlet slurry, the mass percentage concentration of the cone bucket slurry, the mass percentage concentration of the mud discharge slurry, the instantaneous content of the total solid matter in the inlet slurry, the instantaneous content of the total solid matter in the mud discharge, and the total solid matter content in the cone bucket.

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