Full-automatic chemical agent adding device

Abstract

The utility model discloses a full-automatic chemical agent adding device which is suitable for petroleum, chemical engineering and other various process industries needing quantitative chemical agent adding. The device consists of an agent tank with a partition plate, an agent feeding pump, a transfer pump, a dosing metering pump, a related flow meter, a liquid level meter, a liquid level switch and a control system. Through the control logic design of the system, the device can automatically prepare a chemical agent solution with a certain concentration according to requirements, and automatically adjust the agent filling amount in real time according to the flow change and requirements of the filled system. The chemical agent filling device is particularly suitable for unattended chemical agent filling occasions requiring accurate chemical agent adding amount. The device can be designed into integrated skid-mounted equipment, and is small in occupied area, high in integration, accurate in dosing amount and automatic in operation.

Description

Technical Field

[0001] The utility model belongs to the technical field of advanced manufacturing and automation, advanced manufacturing processes and equipment, new machinery, and advanced equipment using automatic control, and particularly relates to the technical field of automatic chemical reagent dosing in the petroleum, chemical, and process industries. Background Art

[0002] In industries such as petroleum and chemical industries, various chemicals and additives need to be added to fluids due to process requirements to improve certain properties of the fluids or devices, such as corrosion inhibitors, scale inhibitors, demulsifiers, neutralizers, etc. A dosing device is required to quantitatively add these chemical reagents into a predetermined fluid or device.

[0003] Generally, a dosing device mainly consists of a solution tank, a stirrer, a metering pump, a filter, a safety valve, a back pressure valve, a check valve, a water level gauge, a pressure gauge, a control cabinet, an installation platform, etc., and is integrally installed on a base. By setting the flow rate of the metering pump, the system is quantitatively dosed with reagents.

[0004] CN202876700U "Dosing Device" discloses a dosing device, which mainly consists of a dosing tank, a stirring system, a control box, and a connecting pipe. The dosing tank is separated into two layers by an intermediate partition. The stirring system stirs the reagents in the upper layer, and the stirred reagents automatically flow into the lower storage tank through the connecting pipe. The liquid level in the storage tank is displayed by a liquid level gauge. A solenoid valve is installed on the connecting pipe, and both the liquid level gauge and the solenoid valve are connected to the control box. The liquid level gauge transmits signals to the control box to control the solenoid valve according to the height of the reagent liquid level, so as to add reagents in a timely manner. The upper and lower medicine boxes are respectively stirred and dosed, and the reagents stirred in the upper layer completely flow into the lower storage tank automatically without power equipment.

[0005] CN204395801U "Dosing Device" discloses a dosing device, which includes a reagent tank and a stirrer. A water inlet and a reagent inlet are respectively arranged on both sides of the stirrer on the reagent tank. A liquid level gauge is arranged under the water inlet, and a safety valve is arranged under the reagent inlet. A metering pump and a drain port are arranged at the bottom of the reagent tank.

[0006] The above processes and technologies have the following disadvantages:

[0007] 1) It cannot automatically prepare a chemical reagent solution with a certain concentration;

[0008] 2) It cannot automatically adjust the concentration of the reagent and automatically adjust the dosing amount according to the dosing requirement.

[0009] Based on the development trend of the process industry, a new generation of fully automatic chemical reagent dosing devices needs to be developed. Summary of the Invention

[0010] The utility model discloses a full-automatic chemical agent dosing device, which is suitable for process industries such as petroleum, chemical industry and other industries that require quantitative dosing of chemical agents. It consists of a chemical agent tank with a partition, an upper agent pump, a transfer pump, a dosing metering pump, relevant flow meters, a liquid level gauge, a liquid level switch and a control system. Through the design of the control logic of the system, the device can automatically prepare a chemical agent solution with a certain concentration according to needs, and automatically adjust the dosing amount of the chemical agent in real time according to the flow rate change and needs of the system to be dosed. The utility model is particularly suitable for chemical agent dosing occasions that are unattended and require accurate dosing amounts. The device can be designed as an integrated skid-mounted equipment, which has a small floor area, high integration, accurate dosing amount, and automatic operation of the device.

[0011] The utility model provides a full-automatic chemical agent dosing device, and its beneficial effects are as follows: 1) Automatically configure a chemical agent with a certain concentration according to the dosing requirements, and automatically inject a specified dose of the chemical agent;

[0012] 2) The device integrates upper agent supply, agent preparation, chemical agent dosing and flow regulation, and is suitable for the needs of unattended and automatic chemical agent dosing in process industries such as petroleum and chemical industry;

[0013] 3) All devices of the device can be integrated on a chassis to form a skid-mounted structure, which is convenient for installation and use. Description of the Drawings

[0014] Figure 1 Schematic diagram of a full-automatic chemical agent dosing device of the utility model:

[0015] Wherein, 1 - chemical agent barrel, 2 - upper agent pump, 3 - upper agent flow meter, 4 - chemical agent tank, 5 - stirrer, 6 - agent preparation liquid level gauge, 7 - process water switch valve, 8 - process water flow meter, 9 - transfer pump, 10 - storage agent liquid level gauge, 11 - metering pump one, 12 - metering pump two, 13 - metering pump three, 14 - valve one, 15 - valve two, 16 - valve three, 17 - valve four, 18 - valve five, 19 - dosing flow meter one, 20 - dosing flow meter two, 21 - injection point flow meter. Detailed Implementation Modes

[0016] The following further elaborates in detail the technical solution of a full-automatic chemical agent dosing device of the utility model in conjunction with the attached Figure 1 specification.

[0017] The integrated full-automatic dosing system includes an upper agent pump, an upper agent flow meter, a process water switch valve, a process water flow meter, a chemical agent tank with a partition (the partition divides the chemical agent tank into two parts: an agent preparation tank and a storage agent tank), a stirrer, a liquid level gauge with high and low liquid level switches, a transfer pump, a metering pump, a dosing flow meter, a control system, etc.

[0018] Taking the dosing system with two injection points as an example, the process flow is as shown in the attached figure. Figure 1 As shown. Chemical agents are generally contained in a dedicated agent barrel (1). The agent is sucked and transported from the agent barrel (1) by the agent pump (2), and then transported to the agent tank (4) after being measured by the agent flow meter (3). The agent tank (4) is a square or round container, which is longitudinally divided into two parts by a partition in the middle, namely, a preparation box and a storage box. The preparation box part is equipped with an agitator (5) and a preparation liquid level meter (6). After the chemical agent enters the agent tank (4), it first enters the preparation box. If the chemical agent does not need to be diluted or dissolved, the storage box can also be omitted. If the chemical solvent needs to be diluted or dissolved, such as the chemical agent needs to be diluted with water, then process water needs to be introduced at this time. The process water comes from outside. When process water needs to be added, the process water switch valve (7) is opened, and the process water is measured by the process water flow meter (8) and then enters the preparation box part of the agent tank (4). Under the stirring action of the agitator (5), the agent is completely diluted. At this time, the transfer pump (9) is started to transfer the prepared chemical agent from the preparation box to the storage box, which is provided with a storage agent liquid level meter (10). At this time, the agent can be pressurized and metered by metering pump 1 (11), metering pump 2 (12) and metering pump 3 (13) respectively, and then transported to the corresponding injection point at a fixed point. The metering pump is a metering pump with variable speed and frequency and adjustable flow. The outlet pipeline of metering pump 1 (11) is provided with valve 1 (14), the outlet pipeline of metering pump 2 (12) is provided with valve 2 (15), the outlet pipeline of metering pump 3 (13) is provided with valve 3 (16), and the outlet collection pipelines of the three metering pumps are provided with valve 4 (17) and valve 5 (18). The injection pipeline of injection point 1 is provided with a dosing flow meter 1 (19), and the injection pipeline of injection point 2 is provided with a dosing flow meter 2 (20). The process medium pipeline that needs to be filled with chemicals is provided with a flow meter (21) at a point of injection. If the first and second dosing points are not in the same pipeline, then each process medium pipeline that needs to be filled with chemicals needs to be provided with a flow meter at a point of injection. This scheme assumes that the first and second dosing points are in the same pipeline, and only the flow meter (21) at the point of injection is provided. The valve can be a manual valve or an automatic valve, which is convenient for automatic program control.

[0019] All signals from the above-mentioned pumps, flow meters, level meters, agitators, automatic valves (if any) and other automatic instruments and motors are fed into the automatic control system (PLC or DCS or other automatic control programs).

[0020] The control logic of the automatic control system is as follows:

[0021] 1. Dosage control when the medicine does not need to be prepared

[0022] The chemical agent barrel (1) is ready. Start the chemical agent feeding pump (2). The chemical agent enters the chemical agent tank (4) from the chemical agent barrel (1). When the dosing level gauge (6) indicates reaching the high level of the chemical agent tank (4) (or when the high-level switch of the level gauge alarms), turn off the chemical agent feeding pump (2) and stop feeding the chemical agent. When the dosing level gauge (6) indicates reaching the low level of the chemical agent tank (4) (or when the low-level switch of the level gauge alarms), start the chemical agent feeding pump (2) and start feeding the chemical agent.

[0023] II. Control of Chemical Agent Feeding When Chemical Agent Preparation is Required

[0024] The chemical agent barrel (1) is ready. Start the chemical agent feeding pump (2). The chemical agent enters the dosing tank of the chemical agent tank (4) from the chemical agent barrel (1). The chemical agent flowmeter (3) accumulates the chemical agent flow. The control program calculates the required chemical agent flow based on the concentration of the chemical agent to be prepared and the volume at the high level of the dosing tank. When the accumulated flow reaches the chemical agent flow, turn off the chemical agent feeding pump (2) and open the process water switch valve (7). The process water flowmeter (8) accumulates the process water flow. The control program calculates the required process water flow based on the concentration of the chemical agent to be prepared and the volume at the high level of the dosing tank. When the accumulated flow reaches the process water flow, close the process water switch valve (7). During the above process, the stirrer (5) is in the on state to stir and mix the process water and the chemical agent. After the feeding of the chemical agent and the process water is completed and the stirrer has run for the specified time, the preparation of the chemical agent solution is completed. At this time, start the transfer pump (9) to transport the chemical agent solvent from the dosing tank to the storage tank. When the level indication of the dosing level gauge (6) is 0 (or when the low-level switch of the level gauge alarms, and the low-level switch alarm value is 0 at this time), turn off the transfer pump (9) and restart the next round of dosing.

[0025] It should be noted that the storage tank and the dosing tank have the same volume, and when the level indication of the storage level gauge (10) is not 0 (or when the low-level switch of the level gauge does not alarm, and the low-level switch alarm value is 0 at this time), the transfer pump (9) does not start. At this time, even if the dosing tank has prepared the chemical agent solution, the transfer pump (9) can only be started when the level indication of the storage level gauge (10) is 0 (or when the low-level switch of the level gauge alarms, and the low-level switch alarm value is 0 at this time).

[0026] III. Control of the Start and Stop of the Metering Pump

[0027] The three metering pumps in this technical solution can simultaneously supply auxiliaries to two different injection points, and the above three pumps are backup to each other. When metering pump one (11) supplies agent to injection point one, metering pump two (12) supplies agent to injection point two, and metering pump three (13) is in standby, valve one (14) is opened, valve two (15) is opened, valve three (16) is closed, valve four (17) is closed, and valve five (18) is opened; when metering pump one (11) supplies agent to injection point one, metering pump two (12) is in standby, and metering pump three (13) supplies agent to injection point two, valve one (14) is opened, valve two (15) is closed, valve three (16) is opened, valve four (17) is closed, and valve five (18) is closed; when metering pump one (11) is in standby, metering pump two (12) supplies agent to injection point one, and metering pump three (13) supplies agent to injection point two, valve one (14) is closed, valve two (15) is opened, valve three (16) is opened, valve four (17) is opened, and valve five (18) is closed.

[0028] IV. Control of Agent Flow

[0029] The flowmeter of the agent injection point (21) transmits the flow rate of the main fluid (process medium) for which the agent needs to be added. The control system automatically calculates the amount of the agent or the amount of the agent solution to be added according to the concentration requirement of the agent to be added, and transmits a signal to the corresponding metering pump to adjust its motor frequency or stroke to achieve the injection of the specified agent or agent solution. A dosing flowmeter one (19) is provided on the injection pipeline of injection point one, and a dosing flowmeter two (20) is provided on the injection pipeline of injection point two to indicate the flow rate of the agent or the agent solution. When the flow rate is lower or higher than the calculated value of the control system, the control system correspondingly adjusts the motor frequency or stroke of the corresponding metering pump until the flow rate is the same as the calculated value of the control system.

Claims

1. An automatic chemical dosing device, characterized in that The device consists of an upper dosing pump, an upper dosing flowmeter, a process water on-off valve, a process water flowmeter, a chemical tank with a partition, a stirrer, a liquid level gauge with high and low liquid level switches, a transfer pump, a metering pump, a chemical dosing flowmeter, a control system, etc.

2. A fully automatic chemical dosing device, characterized in that The chemical tank described in claim 1 is provided with an intermediate partition, which divides the chemical tank into two relatively independent parts, one part is a dosing tank and the other part is a chemical storage tank.

3. A fully automatic chemical dosing device, characterized in that The dosing tank described in claim 2 is equipped with a stirrer.

4. A fully automatic chemical dosing device, characterized in that Both the dosing tank and the chemical storage tank described in claim 2 are equipped with liquid level gauges with high and low liquid level switches, and the high and low liquid levels can be controlled through the liquid level switches.

5. A fully automatic chemical dosing device, characterized in that The metering pump described in claim 1 is equipped with an electric stroke regulator or a motor frequency conversion function, and the injection flow rate of the chemical can be adjusted in real time by adjusting the electric stroke regulator or the motor frequency conversion.

6. A fully automatic chemical dosing device, characterized in that Flowmeters are installed on both the upper dosing pipeline and the process water inlet pipeline, and the concentration of the configured solution can be calculated through the cumulative value of the flow rate of the flowmeter.

7. An automatic chemical dosing device, characterized in that The control system described in claim 1 can collect all parameters within the system, including the process water flow rate, the chemical stock solution flow rate, the high / low liquid levels of the liquid level gauge, the chemical solution flow rate at each chemical injection point, the stroke / motor frequency conversion of the metering pump, and the process medium flow rate.

8. An automatic chemical dosing device, characterized in that The control system described in claim 1 can set up logical control to control the start and stop of the upper dosing pump, the transfer pump, and the metering pump, can control the electric stroke adjustment of the metering pump or other ways to adjust the flow rate, and can control the opening and closing of the process water on-off valve.

9. An automatic chemical dosing device, characterized in that The control system described in claim 1 can set up calculations to calculate the concentration of the configured chemical solution and calculate the dosing amount of the chemical solution based on the process medium flow rate.

10. A fully automatic chemical dosing device, characterized in that A flowmeter is installed on the chemical injection pipeline, which can display the flow rate of the chemical injection in real time.

11. A fully automatic chemical dosing device, characterized in that All the devices described in claim 1 can be integrated on a chassis to form a skid-mounted unit, which is convenient for installation and use.

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