Calcium hydroxide solution preparation device

Abstract

The utility model discloses a calcium hydroxide solution preparation device, which relates to the technical field of wastewater treatment and comprises a calcium oxide storage tank, a PLC (programmable logic controller) control cabinet, a vibrator, an on-line weighing spiral feeding device, an ultrasonic liquid level meter, a stirrer and a calcium hydroxide solution tank. Two ends of the on-line weighing spiral feeding device are respectively connected with a calcium oxide storage tank and a calcium hydroxide solution tank; the bottom of the calcium oxide storage tank is provided with a vibrator, and the top is provided with a radar level gauge; the calcium hydroxide solution tank is provided with an ultrasonic liquid level meter, a water inlet pipe with a water valve and a stirrer; the radar level gauge, the on-line weighing spiral feeding device, the vibrator and the ultrasonic level gauge are all controlled by a PLC (Programmable Logic Controller) control cabinet; and the PLC control cabinet is connected with the HMI. The device can solve the problems that the treatment effect is difficult to guarantee and the labor intensity of operation and maintenance personnel is increased because the concentration of the calcium hydroxide solution cannot be accurately determined in the existing manual preparation of the calcium hydroxide solution.

Description

Technical Field

[0001] The utility model relates to the technical field of wastewater treatment in the steel industry, in particular to an automatic control method and system for preparing a calcium hydroxide solution. Background Art

[0002] Calcium hydroxide solution is an important reagent solution for water treatment in wastewater treatment stations of cold-rolled strip mills. It is mainly used for the neutralization reaction of acidic wastewater. The concentration of calcium hydroxide solution is an important indicator of its quality. The preparation of calcium hydroxide solution is mainly achieved by mixing water and calcium oxide in a certain proportion. Currently, the preparation of calcium hydroxide solution is mainly achieved by semi-automatic or manual preparation. This method has the following problems:

[0003] 1. When using semi-automatic or manual methods, the amount of calcium oxide to be added can only be determined based on experience, and the concentration of the calcium hydroxide solution cannot be accurately determined, which makes it difficult to ensure the effect of wastewater treatment.

[0004] 2. Using semi-automatic or manual methods requires real-time monitoring by personnel. If the concentration is too high, it is easy to clog the pipeline, increasing the labor intensity of operators and maintenance personnel. Utility Model Content

[0005] The technical problem to be solved by the utility model is to provide a calcium hydroxide solution preparation device, which can solve the problems existing in the prior art, such as using a semi-automatic or manual method, only being able to determine the amount of calcium oxide added based on experience, being unable to accurately determine the concentration of the calcium hydroxide solution, resulting in difficulty in ensuring the effect of wastewater treatment during wastewater treatment, and requiring personnel to perform real-time monitoring, which increases the labor intensity of operators and maintenance personnel.

[0006] In order to solve the above problems, the technical solution of the utility model is: the calcium hydroxide solution preparation device includes a calcium oxide storage tank, a radar level meter, a PLC control cabinet, a vibrator, an online weighing screw feeding device, a water valve, an ultrasonic level meter, a mixer and a calcium hydroxide solution tank.

[0007] The bottom outlet of the calcium oxide storage tank is connected to the online weighing screw feeding device, and the other end of the online weighing screw feeding device is connected to the calcium hydroxide solution tank, and the calcium oxide powder is transferred to the calcium hydroxide solution tank through the online weighing screw feeding device; the vibrator is also provided on the outside of the bottom of the calcium oxide storage tank, and the radar level meter is provided on the top of the calcium oxide storage tank.

[0008] The top of the calcium hydroxide solution tank is connected to an online weighing screw feeding device, and is also provided with the ultrasonic level meter and a water inlet pipe. The water inlet pipe is provided with the water valve, and the calcium hydroxide solution tank is provided with the stirrer;

[0009] The radar level meter, the online weighing screw feeding device, the vibrator and the ultrasonic level meter are all controlled by the PLC control cabinet; the PLC control cabinet is connected to the HMI via TCP / IP communication.

[0010] In the above technical solution, a more specific solution is: the online weighing screw feeder device includes a flow stabilizing motor and a metering motor, which are connected to the online weighing screw feeder control cabinet; the online weighing screw feeder control cabinet is connected to the PLC control cabinet and controlled by the PLC control cabinet.

[0011] Furthermore: the PLC control cabinet adopts Siemens S7-1500 control cabinet.

[0012] Furthermore: the specification model of the radar level meter is 7ML5440-0HB00-0AA2.

[0013] Furthermore: The specification model of the ultrasonic level meter is FMU30.

[0014] Furthermore: the specifications of the flow-stabilizing motor and the metering motor are YVF2-90L-4 and YVF2-90L-4 respectively.

[0015] Due to the adoption of the above technical solution, the present invention has the following beneficial effects compared with the prior art:

[0016] 1. The use of the utility model for preparing calcium hydroxide solution greatly improves the control accuracy of the calcium hydroxide solution concentration, reduces the concentration error to ±5%, and ensures the stability of wastewater treatment.

[0017] 2. The use of this utility model improves the degree of automation, eliminates the need for operators to perform real-time monitoring, reduces labor intensity, and improves efficiency.

[0018] 3. The use of the utility model avoids the situation where the pipeline is blocked and the delivery pump is damaged due to excessive concentration caused by unstable control. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic structural diagram of the utility model.

[0020] The numbers in the figure represent:

[0021] 1. Calcium oxide storage tank, 2. Radar level meter, 3. Online weighing screw feeder control cabinet, 4. PLC control cabinet, 5. Vibrator, 6. Online weighing screw feeder, 6-1. Flow stabilizing motor, 6-2. Metering motor, 7. Water valve, 8. HMI, 9. Ultrasonic level meter, 10. Mixer, 11. Calcium hydroxide solution tank. DETAILED DESCRIPTION

[0022] The present invention is further described below with reference to the accompanying drawings and embodiments:

[0023] Figure 1 The calcium hydroxide solution preparation device includes a calcium oxide storage tank 1, a radar level meter 2, an online weighing screw feeder control cabinet 3, a PLC control cabinet 4, a vibrator 5, an online weighing screw feeder 6, a water valve 7, an ultrasonic level meter 9, a mixer 10 and a calcium hydroxide solution tank 11.

[0024] An online weighing screw feeding device 6 is connected to the bottom outlet of the calcium oxide storage tank 1, and the other end of the online weighing screw feeding device 6 is connected to the calcium hydroxide solution tank 11, and the calcium oxide is transferred to the calcium hydroxide solution tank 11 through the online weighing screw feeding device 6; a vibrator 5 is also provided on the outside of the bottom of the calcium oxide storage tank 1, and a radar level meter 2 is provided on the top of the calcium oxide storage tank 1.

[0025] The top of the calcium hydroxide solution tank 11 is connected to the online weighing screw feeding device 6, and is also provided with an ultrasonic level meter 9 and a water inlet pipe on the top, and a water valve 7 is installed on the water inlet pipe; the calcium hydroxide solution tank 11 is also provided with a stirrer 10.

[0026] The online weighing screw feeder device 6 includes a flow-stabilizing motor 6-1 and a metering motor 6-2, which are connected to the online weighing screw feeder control cabinet 3. The online weighing screw feeder control cabinet 3 is connected to the PLC control cabinet 4 of the upper-level PLC control system. The PLC control cabinet 4 of the upper-level PLC control system cooperates with the HMI (Human Machine Interface) 8 through TCP / IP communication.

[0027] In this embodiment, the PLC of the PLC control cabinet 4 of the upper-level PLC control system adopts Siemens S7-1500.

[0028] The radar level meter 2, the online weighing screw feeder control cabinet 3, the vibrator 5, and the ultrasonic level meter 9 are all controlled by a superior Siemens S7-1500 control system. The superior Siemens S7-1500 control system and the HMI are both existing technologies.

[0029] The online weighing screw feeder 6 measures the mass of calcium oxide powder in real time, receives startup commands and calcium oxide flow rate settings from a higher-level PLC control system (i.e., a Siemens S7-1500 control system), and transmits the calcium oxide mass, operating status, and other information to the higher-level PLC control system. An ultrasonic level meter 9, mounted on the calcium hydroxide solution tank 11, measures the liquid level there in real time. During automatic startup, the mixer 10 and water valve 7 are automatically activated. When the liquid level detected by the ultrasonic level meter 9 reaches the set level, the process water supply is stopped, the online weighing screw feeder 6 is activated, and the calcium oxide powder is transported to the calcium oxide storage tank 1. The vibrator 5 is also activated to ensure smooth entry of the calcium oxide powder into the weighing screw feeder 6. When the mass of the calcium oxide powder measured by the online weighing screw feeder 6 reaches the calculated mass, the online weighing screw feeder 6 stops operating. Finally, process water is added again until the liquid level reaches the final set level.

[0030] The basic working principle of the system in this embodiment is:

[0031] 1. The S7-1500 control cabinet of the superior Siemens S7-1500 control system collects the operating signals on site in real time and displays them on the HMI. The concentration, liquid level, start button, calibration button, etc. are set on the HMI.

[0032] 2. When preparing the solution, the HMI sends a start command to the upper-level Siemens S7-1500 control system. The upper-level Siemens S7-1500 control system issues commands to start the mixer and industrial water valve. Industrial water flows into the calcium hydroxide solution tank, and the ultrasonic level meter monitors the liquid level in real time. When the liquid level reaches the set value, the water valve is closed, and the vibrator and online weighing screw feeder are started. Based on the known liquid level and concentration before solution preparation, the mass of calcium hydroxide in the solution before preparation is calculated. Based on the liquid level and concentration set by the HMI, the mass of calcium hydroxide after preparation is calculated. The mass of calcium hydroxide required to be added is subtracted from the two masses. When the difference between the mass of calcium oxide weighed by the online weighing screw feeder and the calculated mass does not exceed the specified value, the online weighing screw feeder and vibrator are stopped. Finally, the water valve is opened until the liquid level measured by the ultrasonic level meter equals the value set by the HMI, completing one solution preparation cycle. In order to improve the degree of automatic control, a radar level meter is installed on the top of the calcium oxide tank. The level meter detects the height of the calcium oxide powder in the tank in real time and displays it on the HMI in real time. When the level is too low, an alarm is issued.

[0033] In this embodiment, the specification model of the radar level meter 2 is 7ML5440-0HB00-0AA2; the specification model of the ultrasonic level meter 9 is FMU30; the specification model of the flow-stabilizing motor 6-1 is YVF2-90L-4; and the specification model of the metering motor 6-2 is YVF2-90L-4.

Claims

1. A calcium hydroxide solution preparation device, characterized in that: It comprises a calcium oxide storage tank (1), a radar level meter (2), a PLC control cabinet (4), a vibrator (5), an online weighing screw feeder (6), a water valve (7), an ultrasonic level meter (9), a mixer (10) and a calcium hydroxide solution tank (11); The two ends of the online weighing screw feeding device (6) are respectively connected to the calcium oxide storage tank (1) and the calcium hydroxide solution tank (11); the vibrator (5) is provided at the bottom of the calcium oxide storage tank (1), and the radar level meter (2) is provided at the top of the calcium oxide storage tank (1); The top of the calcium hydroxide solution tank (11) is provided with the ultrasonic level meter (9) and a water inlet pipe, the water inlet pipe is provided with the water valve (7), and the calcium hydroxide solution tank (11) is also provided with the stirrer (10); The radar level meter (2), the online weighing screw feeder (6), the vibrator (5) and the ultrasonic level meter (9) are all controlled by the PLC control cabinet (4); the PLC control cabinet (4) is connected to the HMI (8).

2. calcium hydroxide solution preparation device according to claim 1, is characterized in that: The online weighing screw feeder device (6) comprises a flow-stabilizing motor (6-1) and a metering motor (6-2), and is connected to an online weighing screw feeder control cabinet (3); the online weighing screw feeder control cabinet (3) is connected to the PLC control cabinet (4) and is controlled by the PLC control cabinet (4).

3. The calcium hydroxide solution preparation device according to claim 1 or 2, wherein: The PLC control cabinet (4) adopts a Siemens S7-1500 control cabinet.

4. calcium hydroxide solution preparation device according to claim 3, is characterized in that: The specification model of the radar level meter (2) is 7ML5440-0HB00-0AA2.

5. calcium hydroxide solution preparation device according to claim 4, is characterized in that: The specification model of the ultrasonic level meter (9) is FMU30.

6. calcium hydroxide solution preparation device according to claim 2, is characterized in that: The specifications of the flow-stabilizing motor (6-1) and the metering motor (6-2) are YVF2-90L-4 and YVF2-90L-4 respectively.

Images