Chemical adding device and chemical adding method

Abstract

The invention discloses a chemical adding device and a chemical adding method, the chemical adding device comprises a chemical storage device, the chemical storage device is connected with a chemical outlet pipe, and the chemical outlet pipe is sequentially connected with a chemical pumping device, a first pressure detection device, a flow detection device and a tail end chemical adding system; the tail end dosing system comprises a branch pipe connected with the medicine outlet pipe, the branch pipe is sequentially connected with second pressure detection equipment, a manual ball valve, a first back pressure valve, a dosing mechanism and a second back pressure valve, and the end of the branch pipe is connected with a tail end dosing port. The medicine adding mechanism comprises a piston fixing shell, and a piston is slidably connected into the piston fixing shell. By controlling the pressure of the medicine outlet pipe, it is ensured that the whole medicine outlet pipe is filled with medicine, the rotating speed of the driving device can be controlled according to the requirements for different medicine adding flows of all medicine adding points, and the accuracy and stability of the medicine adding amount of all the medicine adding points are achieved; and the control difficulty of accurately adjusting the dosage of different medicaments among a plurality of dosing points is effectively reduced.

Description

Technical Field

[0001] The invention relates to the technical field of sewage treatment, and in particular to a dosing device and a dosing method. Background Art

[0002] In the sewage treatment process, the required chemicals are added to improve the sewage purification effect. Common liquid chemicals include carbon sources, flocculants, defoaming agents, acids, alkalis, etc.

[0003] If the liquid agents required by multiple dosing points in different locations are connected, the usual method of dosing is to have a group of pumps (diaphragm pumps, screw pumps, etc.) pumped to each dosing point through a pipeline. The total amount of dosing is adjusted by controlling the operating frequency and number of the pumps, and the dosage distribution of each dosing point is adjusted by controlling the opening of the valves (manual valves, electric valves, etc.) set at each dosing point.

[0004] The flowmeter is usually set at the total outlet of a group of pumps. No flowmeter is set at each dosing point. In addition, the amount of agent added is small, so it is difficult to obtain accurate flow values. It is difficult to accurately control the dosage of each dosing point. It often happens that after the dosage of one dosing point is adjusted, the dosage of other dosing points will change accordingly. The accuracy and stability of the dosage of each dosing point cannot be guaranteed, which seriously affects the sewage treatment effect. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a dosing device and a dosing method, which can accurately control the dosing amount and dosing speed of each dosing point.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] In a first aspect, the present invention provides a dosing device, comprising a medicine storage device, the medicine storage device is connected to a medicine outlet pipe, the medicine outlet pipe is sequentially connected to a medicine pumping device, a first pressure detection device, a flow detection device, and a terminal dosing system;

[0008] The terminal dosing system comprises a branch pipe connected to the drug outlet pipe, the branch pipe is sequentially connected with a second pressure detection device, a manual ball valve, a first back pressure valve, a dosing mechanism, and a second back pressure valve, and the end of the branch pipe is connected with a terminal dosing port;

[0009] The dosing mechanism comprises a piston fixed shell and a driving device fixed shell arranged on the piston fixed shell, a piston is slidably connected in the piston fixed shell, a fixing column is fixedly connected to the upper end surface of the piston, the fixing column is penetrated through the piston fixed shell and slidably connected to the piston fixed shell; a driving device and an extrusion wheel are arranged in the driving device fixed shell, and the driving device is connected to the extrusion wheel through a conveyor belt; the upper end surface of the piston is connected to the inner top wall of the piston fixed shell through a spring; the bottom surface of the extrusion wheel is an inclined surface and abuts against the top of the fixing column; the driving device is used to drive the extrusion wheel to rotate, and the extrusion wheel and the spring drive the fixing column and the piston to perform reciprocating lifting and lowering movements.

[0010] In one embodiment of the present invention, the dosing mechanism also includes a bottom shell, a diaphragm is provided on the upper part of the bottom shell, a piston fixed shell is provided on the upper part of the diaphragm, and an upper cover is provided on the upper part of the driving device fixed shell, and the bottom shell, diaphragm, piston fixed shell, driving device fixed shell, and upper cover are fixedly connected by bolts.

[0011] In one embodiment of the present invention, an inlet and an outlet are provided on the bottom shell, a dosing chamber is formed between the bottom shell and the diaphragm, the dosing chamber is connected to the first back pressure valve through the inlet of the bottom shell, and the dosing chamber is connected to the second back pressure valve through the outlet of the bottom shell.

[0012] In one embodiment of the present invention, a plurality of the springs are arranged around the fixing column, one end of each of the springs is hinged to the upper end surface of the piston, and the other end is hinged to the inner top wall of the piston fixing shell.

[0013] In one embodiment of the present invention, a pressurized chamber is formed between the piston fixed housing, the piston and the diaphragm, and the pressurized chamber is filled with an incompressible liquid.

[0014] In one embodiment of the present invention, the upper end surface of the piston is also fixedly connected to a plurality of positioning columns, and the plurality of positioning columns are arranged around the fixed column. Each of the positioning columns is provided with an injection hole connected to the pressurized chamber, and the end of each of the positioning columns is also provided with an injection hole plug for blocking the injection hole.

[0015] In one embodiment of the present invention, a control cabinet is further included, and the medicine storage device, the medicine pumping equipment, the first pressure detection equipment, the flow detection equipment, and the medicine adding mechanism are all electrically connected to the control cabinet.

[0016] In a second aspect, the present invention provides a dosing method, using the above-mentioned dosing device, and multiple groups of terminal dosing ports of the terminal dosing system are respectively installed at various dosing points of the sewage treatment plant, and the dosing method comprises the following steps:

[0017] S1: The prepared liquid medicine is stored in a medicine storage device;

[0018] S2: The medicine pumping device pumps the medicine in the medicine storage device to each terminal dosing system through the medicine outlet pipe, and a first pressure detection device and a flow detection device are arranged on the medicine outlet pipe at the outlet position of the medicine pumping device to detect the pressure value and flow value of the medicine outlet pipe;

[0019] S3: During the drug delivery process, the pressure change in the drug tube is detected by the first pressure detection device. When the pressure is less than the set pressure, the working frequency of the drug pumping device is increased. The greater the difference between the detected pressure and the set value, the faster the working frequency of the drug pumping device changes. The smaller the difference between the detected pressure and the set value, the slower the working frequency of the drug pumping device changes, so that the pressure in the drug delivery tube is stabilized at the set pressure.

[0020] S4: When the dosing point needs to add medicine, the manual ball valve is opened, and the medicine flows from the medicine outlet pipe to the branch pipe, and then flows through the second pressure detection device, the manual ball valve, the first back pressure valve, the dosing mechanism, the second back pressure valve, and finally flows out through the end dosing port;

[0021] S5: The driving device in the dosing mechanism rotates the extrusion wheel through the conveyor belt. During the rotation of the extrusion wheel, the inclined surface at the bottom thereof moves from the highest point to the lowest point and then from the lowest point to the highest point in a cycle;

[0022] S6: The piston fixing housing and the piston in the dosing mechanism are connected by a spring. When the piston is not subjected to external force, the piston abuts against the lower end surface of the extrusion wheel by the tension of the spring;

[0023] S7: The pressure of the medicine outlet pipe is the pressure before the first back pressure valve, and the pressure of the medicine adding chamber is the pressure after the first back pressure valve. When the pressure difference between the medicine outlet pipe and the medicine adding chamber is greater than the opening pressure of the first back pressure valve, the first back pressure valve is opened, so that the medicine can flow through the first back pressure valve to fill the medicine adding chamber of the medicine adding mechanism. When the medicine adding chamber is full of medicine, the pressure difference before and after the first back pressure valve is less than the opening pressure of the first back pressure valve, and the first back pressure valve is closed.

[0024] S8: The pressure of the dosing chamber is the pressure before the second back pressure valve, the end dosing port is open, and the atmospheric pressure is the pressure after the second back pressure valve. When the pressure difference between the dosing chamber and the atmospheric pressure is less than the opening pressure of the second back pressure valve, the second back pressure valve does not open, and the medicine cannot flow through the second back pressure valve and out of the end dosing port;

[0025] S9: When the contact point between the bottom surface of the extrusion wheel and the fixed column rotates from the highest point to the lowest point, the bottom surface of the extrusion wheel squeezes the piston through the fixed column, overcomes the spring tension, and moves the piston downward, and squeezes the pressurizing chamber through the piston. Since the liquid in the pressurizing chamber is incompressible, the diaphragm moves downward, thereby squeezing the medicine adding chamber, overcoming the pressure of the second back pressure valve, and squeezing the medicine from the outlet of the bottom shell. When the piston reaches the lowest point, no pressure is generated on the pressurizing chamber, and the second back pressure valve is closed;

[0026] S10: When the bottom surface of the extrusion wheel rotates from the lowest point to the highest point at the contact point with the fixed column, the piston loses the pressure of the extrusion wheel, and under the action of the spring tension, the piston follows the bottom surface of the extrusion wheel and moves from the lowest point to the highest point, the diaphragm moves upward, and the pressure in the dosing chamber decreases. When the pressure difference before and after the first back pressure valve is greater than the opening pressure of the first back pressure valve, return to S7 cycle;

[0027] S11: The piston moves from the highest point to the lowest point and then to the highest point for one reciprocating cycle. When the piston moves from the highest point to the lowest point, the medicine flows out of the dosing port at the end. When the piston moves from the lowest point to the highest point, no medicine flows out of the dosing port at the end.

[0028] S12: The driving device controls the reciprocating frequency of the piston by controlling the rotation speed of the extrusion wheel. The higher the reciprocating frequency, the more medicine flows out of the end dosing port. The rotation speed requirement of the driving device is calculated according to the medicine flow rate required by the end dosing port.

[0029] In one embodiment of the present invention, the relevant calculation in S12 is as follows:

[0030] The volume of the medicine squeezed out in a single cycle of the reciprocating motion of the piston is V, in mL;

[0031] The speed of the driving device is N1, in r / min;

[0032] The transmission ratio of the driving device and the extrusion wheel is n, n = N1 / N2;

[0033] The rotation period of the extrusion wheel is T2, in min, and the rotation speed is N2;

[0034] The reciprocating period of the piston is the same as the rotation period of the extrusion wheel, T2 = 1 / N2;

[0035] The flow rate of the terminal dosing port is Q=V / T2=N1V / n, in mL / min;

[0036] The rotation speed N1 of the driving device is Qn / V, and the unit is r / min.

[0037] In one embodiment of the present invention, a plurality of terminal dosing systems are connected to the drug outlet pipe, one end of each of the plurality of terminal dosing systems is connected to the drug outlet pipe, and the other end is connected to the terminal dosing port; when a group of terminal dosing systems is selected, during a single piston reciprocating cycle, during the movement of the piston from the lowest point to the highest point, no medicine is discharged from the terminal dosing port, and the dosing process is discontinuous. If continuous dosing is required, two groups of terminal dosing systems are selected to operate in parallel, and when the piston of one dosing mechanism moves from the lowest point to the highest point, the piston of the other dosing mechanism moves from the highest point to the lowest point, so as to ensure the continuity of the discharge of medicine from the terminal dosing port.

[0038] Beneficial effects of the present invention:

[0039] The present invention provides a dosing device and a dosing method, which can drive the fixed column and the piston to perform reciprocating lifting motion through the combined action of an extrusion wheel and a spring, so that the piston reciprocates up and down in the piston fixed shell. The movement of the piston from the highest point to the lowest point and then to the highest point is a reciprocating cycle. When the piston moves from the highest point to the lowest point, medicine flows out of the end dosing port. When the piston moves from the lowest point to the highest point, no medicine flows out of the end dosing port. The reciprocating frequency of the piston is controlled by controlling the speed of the extrusion wheel through a driving device. The higher the reciprocating frequency, the more medicine flows out of the end dosing port. Therefore, the flow rate of the medicine at the end dosing port can be controlled by controlling the speed of the driving device, so that the dosage and dosing speed of each dosing point can be accurately controlled, so as to ensure the accuracy and stability of the dosage at each dosing point and avoid affecting the sewage treatment effect. To sum up, during use, the present invention ensures that the entire medicine outlet pipe is filled with medicine by controlling the pressure of the medicine outlet pipe, and can control the rotation speed of the driving device according to the different medicine dosing flow requirements of each dosing point, thereby achieving the accuracy and stability of the medicine dosage of each dosing point, and effectively reducing the difficulty of accurately adjusting the control of different medicine dosages between multiple dosing points. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 A schematic diagram of the system composition of a dosing device provided by the present invention.

[0041] Figure 2 This is a schematic diagram of the structural composition of the terminal dosing system provided by the present invention.

[0042] Figure 3 This is a schematic diagram of the structural disassembly of the medicine adding mechanism provided by the present invention.

[0043] Figure 4 This is a schematic diagram of the piston of the dosing mechanism provided by the present invention rotating to one of the positions.

[0044] Figure 5 This is a schematic diagram of the piston of the dosing mechanism provided by the present invention rotating to another position.

[0045] Figure 6 This is a front view of the medicine adding mechanism provided by the present invention.

[0046] Figure 7 for Figure 6 AA section view in.

[0047] Figure 8 A top view of the piston of the dosing mechanism provided by the present invention.

[0048] Fig. 9 for Figure 8 BB section view in.

[0049] Fig.10 This is a schematic diagram of the structural composition of two groups of terminal dosing systems provided by the present invention.

[0050] Among them: 1. medicine storage device; 2. medicine pumping equipment; 3. first pressure detection equipment; 4. flow detection equipment; 5. medicine outlet pipe; 6. terminal dosing system; 7. control cabinet; 61. branch pipe; 62. second pressure detection equipment; 63. manual ball valve; 64. first back pressure valve; 65. dosing mechanism; 66. second back pressure valve; 67. terminal dosing port; 651. bottom shell; 652. diaphragm; 653. piston; 6531. fixing column; 6532. positioning column; 654. spring; 655. piston fixed shell; 656. extrusion wheel; 657. driving device; 658. conveyor belt; 659. driving device fixed shell; 6510. upper cover; 6511. bolt; 6512. dosing chamber; 6513. pressurizing chamber; 6561. injection hole; 6562. injection hole plug. DETAILED DESCRIPTION

[0051] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. 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 creative work are within the scope of protection of the present invention.

[0052] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance. Among them, the terms "first position" and "second position" are two different positions.

[0053] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection or a detachable connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0054] like Figure 1 As shown, the present invention provides a dosing device. In some embodiments, the dosing device includes a medicine storage device 1, and the medicine storage device 1 is connected to a medicine outlet pipe 5, and the medicine outlet pipe 5 is sequentially connected to a medicine pumping device 2, a first pressure detection device 3, a flow detection device 4, and a terminal dosing system 6.

[0055] like Figure 2 As shown, in some embodiments, the terminal dosing system 6 includes a branch pipe 61 connected to the drug outlet pipe 5, and the branch pipe 61 is sequentially connected to a second pressure detection device 62, a manual ball valve 63, a first back pressure valve 64, a dosing mechanism 65, and a second back pressure valve 66, and the end of the branch pipe 61 is connected to a terminal dosing port 67.

[0056] like Figure 3-Figure 9 As shown, in some embodiments, the dosing mechanism 65 includes a bottom shell 651, a diaphragm 652 is provided on the top of the bottom shell 651, a piston fixed shell 655 is provided on the top of the diaphragm 652, a drive device fixed shell 659 is provided on the top of the piston fixed shell 655, and an upper cover 6510 is provided on the top of the drive device fixed shell 659. The bottom shell 651, the diaphragm 652, the piston fixed shell 655, the drive device fixed shell 659, and the upper cover 6510 are fixedly connected by bolts 6511.

[0057] Furthermore, an inlet and an outlet are provided on the bottom shell 651 , and a dosing chamber 6512 is formed between the bottom shell 651 and the diaphragm 652 . The dosing chamber 6512 is connected to the first back pressure valve 64 through the inlet of the bottom shell 651 , and is connected to the second back pressure valve 66 through the outlet of the bottom shell 651 .

[0058] Furthermore, a piston 653 is slidably connected inside the piston fixed shell 655, and a fixed column 6531 is fixedly connected to the upper end surface of the piston 653. The fixed column 6531 penetrates the piston fixed shell 655 and is slidably connected to the piston fixed shell 655; a driving device 657 and an extrusion wheel 656 are provided inside the driving device fixed shell 659, and the driving device 657 is drivingly connected to the extrusion wheel 656 through a conveyor belt 658; the upper end surface of the piston 653 is connected to the inner top wall of the piston fixed shell 655 through a spring 654; the bottom surface of the extrusion wheel 656 is an inclined surface, and abuts against the top of the fixed column 6531; the driving device 657 is used to drive the extrusion wheel 656 to rotate, and the extrusion wheel 656 and the spring 654 drive the fixed column 6531 and the piston 653 to perform reciprocating lifting and lowering movements.

[0059] In this embodiment, since the bottom surface of the extrusion wheel 656 is an inclined surface and abuts against the top of the fixed column 6531, the driving device 657 drives the extrusion wheel 656 to rotate. When the bottom surface of the extrusion wheel 656 rotates from the highest point to the lowest point at the contact point with the fixed column 6531, the piston 653 moves downward by extruding the piston 653; when the bottom surface of the extrusion wheel 656 rotates from the lowest point to the highest point at the contact point with the fixed column 6531, the piston 653 moves upward by the elastic force of the spring 654. Therefore, through the combined action of the extrusion wheel 656 and the spring 654, the fixed column 6531 and the piston 653 can be driven to perform reciprocating lifting and lowering motions, so that the piston 653 reciprocates up and down in the piston fixing housing 655.

[0060] Optionally, a plurality of springs 654 are arranged around the fixed column 6531 , and one end of each spring 654 is hinged to the upper end surface of the piston 653 , and the other end is hinged to the inner top wall of the piston fixed shell 655 .

[0061] In this embodiment, a plurality of springs 654 are arranged around the fixed column 6531 so that when the springs 654 pull the piston 653 upward, the pulling force is more uniform, and the piston 653 can be smoothly pulled up steadily, thereby ensuring that the piston 653 performs a smooth up and down reciprocating motion in the piston fixed housing 655.

[0062] Furthermore, a pressurizing chamber 6513 is formed between the piston fixing housing 655 , the piston 653 and the diaphragm 652 , and the pressurizing chamber 6513 is filled with an incompressible liquid.

[0063] Furthermore, the upper end surface of the piston 653 is also fixedly connected with a plurality of positioning columns 6532, and the plurality of positioning columns 6532 are arranged around the fixed column 6531, and each positioning column 6532 is provided with a liquid injection hole 6561 connected to the pressurizing chamber 6513, and the end of each positioning column 6532 is also provided with a liquid injection hole plug 6562 for plugging the liquid injection hole 6561. After the pressurizing chamber 6513 is filled with the incompressible liquid, the liquid injection hole plug 6562 is screwed on to ensure that there is no gas in the chamber.

[0064] Optionally, a control cabinet 7 is further included, and the medicine storage device 1, medicine pumping device 2, first pressure detection device 3, flow detection device 4, and medicine adding mechanism 65 are all electrically connected to the control cabinet 7. The control cabinet 7 controls the operation of each of the above devices.

[0065] In some embodiments, the drug outlet pipe 5 is connected to a plurality of terminal drug adding systems 6 , one end of each of the plurality of terminal drug adding systems 6 is connected to the drug outlet pipe 5 , and the other end of each of the plurality of terminal drug adding systems 6 is connected to the terminal drug adding port 67 .

[0066] like Fig.10 As shown, in this embodiment, the terminal dosing system 6 is divided into two groups.

[0067] In addition, the present invention also provides a dosing method, using the above-mentioned dosing device, and multiple groups of terminal dosing ports 67 of the terminal dosing system 6 are respectively installed at various dosing points of the sewage treatment plant. The dosing method includes the following steps:

[0068] S1: The prepared liquid medicine is stored in the medicine storage device 1;

[0069] S2: The medicine pumping device 2 pumps the medicine in the medicine storage device 1 to each terminal dosing system 6 through the medicine outlet pipe 5, and a first pressure detection device 3 and a flow detection device 4 are arranged on the medicine outlet pipe 5 at the outlet position of the medicine pumping device 2 to detect the pressure value and flow value of the medicine outlet pipe 5;

[0070] S3: During the drug delivery process, the pressure change in the drug tube 5 is detected by the first pressure detection device 3. When the pressure is less than the set pressure, the working frequency of the drug pumping device 2 is increased. The greater the difference between the detected pressure and the set value, the faster the working frequency of the drug pumping device 2 changes. The smaller the difference between the detected pressure and the set value, the slower the working frequency of the drug pumping device 2 changes, so that the pressure in the drug delivery tube 5 is stabilized at the set pressure as soon as possible.

[0071] S4: When the dosing point needs to add medicine, the manual ball valve 63 is opened, and the medicine flows from the medicine outlet pipe 5 to the branch pipe 61, and then flows through the second pressure detection device 62, the manual ball valve 63, the first back pressure valve 64, the dosing mechanism 65, the second back pressure valve 66, and finally flows out through the terminal dosing port 67;

[0072] S5: The driving device 657 in the medicine adding mechanism 65 rotates the extrusion wheel 656 through the conveyor belt 658. During the rotation of the extrusion wheel 656, the inclined surface at the bottom thereof moves from the highest point to the lowest point and then from the lowest point to the highest point in a cycle;

[0073] S6: The piston fixed housing 655 and the piston 653 in the dosing mechanism 65 are connected via a spring 654. When the piston 653 is not subjected to external force, the piston 653 abuts against the lower end surface of the extrusion wheel 656 by the pulling force of the spring 654;

[0074] S7: The pressure of the medicine outlet pipe 5 is the pressure before the first back pressure valve 64, and the pressure of the medicine adding chamber 6512 is the pressure after the first back pressure valve 64. When the pressure difference between the medicine outlet pipe 5 and the medicine adding chamber 6512 is greater than the opening pressure of the first back pressure valve 64, the first back pressure valve 64 is opened, so that the medicine can flow through the first back pressure valve 64 to fill the medicine adding chamber 6512 of the medicine adding mechanism 65. When the medicine adding chamber 6512 is full of medicine, the pressure difference before and after the first back pressure valve 64 is less than the opening pressure of the first back pressure valve 64, and the first back pressure valve 64 is closed;

[0075] S8: The pressure of the dosing chamber 6512 is the pressure before the second back pressure valve 66, the terminal dosing port 67 is open, and the atmospheric pressure is the pressure after the second back pressure valve 66. When the pressure difference between the dosing chamber 6512 and the atmospheric pressure is less than the opening pressure of the second back pressure valve 66, the second back pressure valve 66 does not open, and the medicine cannot flow through the second back pressure valve 66 and out of the terminal dosing port 67;

[0076] S9: When the contact point between the bottom surface of the extrusion wheel 656 and the fixed column 6531 rotates from the highest point to the lowest point, the bottom surface of the extrusion wheel 656 squeezes the piston 653 through the fixed column 6531, overcomes the pulling force of the spring 654, and makes the piston 653 move downward, and squeezes the pressurizing chamber 6513 through the piston 653. Since the liquid in the pressurizing chamber 6513 is incompressible, the diaphragm 652 moves downward, thereby squeezing the medicine adding chamber 6512, overcoming the pressure of the second back pressure valve 66, and squeezing the medicine from the outlet of the bottom shell 651. When the piston 653 reaches the lowest point, no more pressure is generated on the pressurizing chamber 6513, and the second back pressure valve 66 is closed;

[0077] S10: When the bottom surface of the extrusion wheel 656 rotates from the lowest point to the highest point at the contact point with the fixed column 6531, the piston 653 loses the pressure of the extrusion wheel 656, and the piston 653 is driven by the tension of the spring 654 to move from the lowest point to the highest point following the bottom surface of the extrusion wheel 656, and the diaphragm 652 moves upward, and the pressure in the dosing chamber 6512 decreases. When the front and rear pressure difference of the first back pressure valve 64 is greater than the opening pressure of the first back pressure valve 64, the cycle returns to S7;

[0078] S11: The piston 653 moves from the highest point to the lowest point and then to the highest point for one reciprocating cycle. When the piston 653 moves from the highest point to the lowest point, the medicine flows out of the medicine adding port 67. When the piston 653 moves from the lowest point to the highest point, no medicine flows out of the medicine adding port 67.

[0079] S12: The driving device 657 controls the reciprocating frequency of the piston 653 by controlling the rotation speed of the extrusion wheel 656. The higher the reciprocating frequency, the more medicine flows out of the terminal dosing port 67. The rotation speed requirement of the driving device 657 can be calculated according to the medicine flow rate required by the terminal dosing port 67.

[0080] Optionally, the relevant calculation in S12 is as follows:

[0081] The volume of the medicine squeezed out by the piston 653 in a single reciprocating motion cycle is V (in mL);

[0082] The speed of the driving device 657 is N1 (in r / min);

[0083] The transmission ratio of the driving device 657 and the extrusion wheel 656 is n (n=N1 / N2);

[0084] The rotation period of the extrusion wheel 656 is T2 (in min) and the rotation speed is N2;

[0085] The reciprocating period of the piston 653 and the rotation period of the extrusion wheel 656 are T2 (T2=1 / N2);

[0086] The flow rate of the terminal dosing port 67 is Q=V / T2=N1V / n (in mL / min);

[0087] The rotation speed N1 of the driving device 657 is QN / V (in r / min).

[0088] Among them, when a group of terminal dosing systems 6 is selected, within the reciprocating cycle of a single piston 653, during the movement of the piston 653 from the lowest point to the highest point, the terminal dosing port 67 does not discharge medicine, and the dosing process is discontinuous. If continuous dosing is required, two groups of terminal dosing systems 6 are selected to operate in parallel. When the piston 653 of one group of dosing mechanisms 65 moves from the lowest point to the highest point, the piston 653 of the other group of dosing mechanisms 65 moves from the highest point to the lowest point, which can ensure the continuity of the discharge of medicine from the terminal dosing port 67.

[0089] The present invention provides a dosing device and a dosing method. Through the combined action of the extrusion wheel 656 and the spring 654, the fixed column 6531 and the piston 653 can be driven to perform reciprocating lifting and lowering motions, so that the piston 653 reciprocates up and down in the piston fixed housing 655. The movement of the piston 653 from the highest point to the lowest point and then to the highest point is a reciprocating cycle. The piston 653 moves from the highest point to the lowest point and the end dosing port 67 has medicine flowing out. The piston 653 moves from the lowest point to the highest point and the end dosing port 67 has no medicine flowing out. The reciprocating frequency of the piston 653 is controlled by controlling the rotation speed of the extrusion wheel 656 through the driving device 657. The higher the reciprocating frequency, the more medicine flows out of the end dosing port 67. Therefore, the medicine flow rate of the end dosing port 67 can be controlled by controlling the rotation speed of the driving device 657, so that the dosage and dosing speed of each dosing point can be accurately controlled, and the accuracy and stability of the dosage of each dosing point can be ensured to avoid affecting the treatment effect of sewage. To sum up, during use, the present invention ensures that the entire medicine outlet pipe is filled with medicine by controlling the pressure of the medicine outlet pipe, and can control the rotation speed of the driving device according to the different medicine dosing flow requirements of each dosing point, thereby achieving the accuracy and stability of the medicine dosage of each dosing point, and effectively reducing the difficulty of accurately adjusting the control of different medicine dosages between multiple dosing points.

[0090] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention, and should be included in the protection scope of the present invention.

Claims

1. A dosing device, characterized in that: It comprises a medicine storage device, the medicine storage device is connected to a medicine outlet pipe, and the medicine outlet pipe is sequentially connected to a medicine pumping device, a first pressure detection device, a flow detection device, and a terminal dosing system; The terminal dosing system comprises a branch pipe connected to the drug outlet pipe, the branch pipe is sequentially connected with a second pressure detection device, a manual ball valve, a first back pressure valve, a dosing mechanism, and a second back pressure valve, and the end of the branch pipe is connected with a terminal dosing port; The dosing mechanism comprises a piston fixed shell and a driving device fixed shell arranged on the piston fixed shell, a piston is slidably connected in the piston fixed shell, a fixing column is fixedly connected to the upper end surface of the piston, the fixing column is penetrated through the piston fixed shell and slidably connected to the piston fixed shell; a driving device and an extrusion wheel are arranged in the driving device fixed shell, and the driving device is connected to the extrusion wheel through a conveyor belt; the upper end surface of the piston is connected to the inner top wall of the piston fixed shell through a spring; the bottom surface of the extrusion wheel is an inclined surface and abuts against the top of the fixing column; the driving device is used to drive the extrusion wheel to rotate, and the extrusion wheel and the spring drive the fixing column and the piston to perform reciprocating lifting and lowering movements.

2. A dosing device according to claim 1, characterized in that: The dosing mechanism also includes a bottom shell, a diaphragm is provided on the top of the bottom shell, a piston fixed shell is provided on the top of the diaphragm, an upper cover is provided on the top of the drive device fixed shell, and the bottom shell, diaphragm, piston fixed shell, drive device fixed shell, and upper cover are fixedly connected by bolts.

3. A dosing device according to claim 2, characterized in that: The bottom shell is provided with an inlet and an outlet, a medicine adding chamber is formed between the bottom shell and the diaphragm, the medicine adding chamber is connected to the first back pressure valve through the inlet of the bottom shell, and the medicine adding chamber is connected to the second back pressure valve through the outlet of the bottom shell.

4. A dosing device according to claim 3, characterized in that: A plurality of springs are arranged around the fixing column, one end of each spring is hinged to the upper end surface of the piston, and the other end is hinged to the inner top wall of the fixing shell of the piston.

5. A dosing device according to claim 4, characterized in that: A pressurized chamber is formed between the piston fixed housing, the piston and the diaphragm, and the pressurized chamber is filled with incompressible liquid.

6. A dosing device according to claim 5, characterized in that: The upper end surface of the piston is also fixedly connected to a plurality of positioning columns, which are arranged around the fixed column. Each of the positioning columns is provided with an injection hole connected to the pressurized chamber, and the end of each positioning column is also provided with an injection hole plug for blocking the injection hole.

7. A dosing device according to claim 6, characterized in that: It also includes a control cabinet, and the medicine storage device, medicine pumping equipment, first pressure detection equipment, flow detection equipment, and medicine adding mechanism are all electrically connected to the control cabinet.

8. A method for adding medicine, characterized in that: A dosing device according to any one of claims 1 to 7 is used, and multiple groups of terminal dosing ports of the terminal dosing system are respectively installed at various dosing points of the sewage treatment plant, and the dosing method comprises the following steps: S1: The prepared liquid medicine is stored in a medicine storage device; S2: The medicine pumping device pumps the medicine in the medicine storage device to each terminal dosing system through the medicine outlet pipe, and a first pressure detection device and a flow detection device are arranged on the medicine outlet pipe at the outlet position of the medicine pumping device to detect the pressure value and flow value of the medicine outlet pipe; S3: During the drug delivery process, the pressure change in the drug tube is detected by the first pressure detection device. When the pressure is less than the set pressure, the working frequency of the drug pumping device is increased. The greater the difference between the detected pressure and the set value, the faster the working frequency of the drug pumping device changes. The smaller the difference between the detected pressure and the set value, the slower the working frequency of the drug pumping device changes, so that the pressure in the drug delivery tube is stabilized at the set pressure. S4: When the dosing point needs to add medicine, the manual ball valve is opened, and the medicine flows from the medicine outlet pipe to the branch pipe, and then flows through the second pressure detection device, the manual ball valve, the first back pressure valve, the dosing mechanism, the second back pressure valve, and finally flows out through the end dosing port; S5: The driving device in the dosing mechanism rotates the extrusion wheel through the conveyor belt. During the rotation of the extrusion wheel, the inclined surface at the bottom thereof moves from the highest point to the lowest point and then from the lowest point to the highest point in a cycle; S6: The piston fixing housing and the piston in the dosing mechanism are connected by a spring. When the piston is not subjected to external force, the piston abuts against the lower end surface of the extrusion wheel by the tension of the spring; S7: The pressure of the medicine outlet pipe is the pressure before the first back pressure valve, and the pressure of the medicine adding chamber is the pressure after the first back pressure valve. When the pressure difference between the medicine outlet pipe and the medicine adding chamber is greater than the opening pressure of the first back pressure valve, the first back pressure valve is opened, so that the medicine can flow through the first back pressure valve to fill the medicine adding chamber of the medicine adding mechanism. When the medicine adding chamber is full of medicine, the pressure difference before and after the first back pressure valve is less than the opening pressure of the first back pressure valve, and the first back pressure valve is closed. S8: The pressure of the dosing chamber is the pressure before the second back pressure valve, the end dosing port is open, and the atmospheric pressure is the pressure after the second back pressure valve. When the pressure difference between the dosing chamber and the atmospheric pressure is less than the opening pressure of the second back pressure valve, the second back pressure valve does not open, and the medicine cannot flow through the second back pressure valve and out of the end dosing port; S9: When the contact point between the bottom surface of the extrusion wheel and the fixed column rotates from the highest point to the lowest point, the bottom surface of the extrusion wheel squeezes the piston through the fixed column, overcomes the spring tension, and moves the piston downward, and squeezes the pressurizing chamber through the piston. Since the liquid in the pressurizing chamber is incompressible, the diaphragm moves downward, thereby squeezing the medicine adding chamber, overcoming the pressure of the second back pressure valve, and squeezing the medicine from the outlet of the bottom shell. When the piston reaches the lowest point, no pressure is generated on the pressurizing chamber, and the second back pressure valve is closed; S10: When the bottom surface of the extrusion wheel rotates from the lowest point to the highest point at the contact point with the fixed column, the piston loses the pressure of the extrusion wheel, and under the action of the spring tension, the piston follows the bottom surface of the extrusion wheel and moves from the lowest point to the highest point, the diaphragm moves upward, and the pressure in the dosing chamber decreases. When the pressure difference before and after the first back pressure valve is greater than the opening pressure of the first back pressure valve, return to S7 cycle; S11: The piston moves from the highest point to the lowest point and then to the highest point for one reciprocating cycle. When the piston moves from the highest point to the lowest point, the medicine flows out of the dosing port at the end. When the piston moves from the lowest point to the highest point, no medicine flows out of the dosing port at the end. S12: The driving device controls the reciprocating frequency of the piston by controlling the rotation speed of the extrusion wheel. The higher the reciprocating frequency, the more medicine flows out of the end dosing port. The rotation speed requirement of the driving device is calculated according to the medicine flow rate required by the end dosing port.

9. A dosing method according to claim 8, characterized in that: The relevant calculation in S12 is as follows: The volume of the medicine squeezed out in a single cycle of the reciprocating motion of the piston is V, in mL; The speed of the driving device is N1, in r / min; The transmission ratio of the driving device and the extrusion wheel is n, n = N1 / N2; The rotation period of the extrusion wheel is T2, in min, and the rotation speed is N2; The reciprocating period of the piston is the same as the rotation period of the extrusion wheel, T2 = 1 / N2; The flow rate of the terminal dosing port is Q=V / T2=N1V / n, in mL / min; The rotation speed N1 of the driving device is Qn / V, and the unit is r / min.

10. A dosing method according to claim 9, characterized in that: The drug outlet pipe is connected with a plurality of terminal drug dosing systems, one end of each of the plurality of terminal drug dosing systems is connected with the drug outlet pipe, and the other end is connected with the terminal drug dosing port. When one group of terminal drug dosing systems is selected, during a single piston reciprocating cycle, during the movement of the piston from the lowest point to the highest point, no drug is discharged from the terminal drug dosing port, and the drug dosing process is discontinuous. If continuous drug dosing is required, two groups of terminal drug dosing systems are selected to operate in parallel. When the piston of one group of drug dosing mechanisms moves from the lowest point to the highest point, the piston of the other group of drug dosing mechanisms moves from the highest point to the lowest point, so as to ensure the continuity of drug discharge from the terminal drug dosing port.

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