Precautions for operating the automatic drug dispensing device

Automatic Chemical Dosing Device Operation Precautions

1. The dosing pump motor is controlled by a variable frequency drive. If the dosing pump malfunctions, it may be due to a variable frequency drive failure. In this case, another unit (normally one main and one backup) should be activated, and the fault should be reset according to the instructions.

2. During the use of the level meter, if the material is damp and sticky, it will affect the use effect on the surface of the level switch. The dosing device should be checked and wiped frequently (it is recommended to do it once per shift).

3. Water is prohibited from entering the electrical components in the control cabinet. The cabinet door should be kept closed during normal use, and the control cabinet should not be washed with water. Otherwise, the electrical components will be damaged.

4. Because the chemical agent is highly corrosive, the mechanical parts in contact with the chemical agent should be checked and replaced regularly.

5. If the screen inside the feeder is damaged, please replace it in time to prevent large pieces of dry chemical agent from entering the spiral feeder, damaging the spiral or drive motor.

6. The two pressure-type level gauges should be checked and cleaned once a month.

7. Due to the viscosity of the chemical agent, attention should be paid to the smoothness of the feeding pipeline during blowing, especially at the bottom of the hopper and the outlet.

8. Normally, open the end cap at the top of the hopper, there is a downward suction force. If there is no suction force or backwind, it indicates that the feeding pipeline is not smooth, and it should be checked in time. (It is recommended to disassemble and check every 20 hours of dosing operation).

9. There is a heater in the hopper. Normally, the air is sent for a period of time, and the feeding pipe is slightly warm. If there is no change, it indicates that the heater is damaged, and it should be checked and replaced in time.

10. The inlet valve and outlet valve are automatic ball valves. If water still flows in or chemicals flow out after closing, it indicates that the inlet valve and outlet valve are damaged, and they should be checked and replaced in time.

11. The dosing pump is prohibited from idling and reversing. Before starting the pump, it must be ensured that the valves before and after the metering pump are opened, and the medium must be pre-injected.

Chemical Dosing Methods

1. Adding dechlorinating agent

Pure water machine model, raw water inflow (tons/hour), dosage (grams) for every 57 liters of pure water, dosing method:

Add before pretreatment inflow, adjust the dosing machine flow rate to about 2.5 liters/hour;

Note: If the residual chlorine concentration is greater than 0.5 mg/L, double the amount of dechlorinating agent in the dosing tank. Multiple = residual chlorine concentration / 0.5;

2. Adding flocculant

Using tap water as the water source, turbidity is less than 5 degrees.

Pure water machine model, raw water inflow (tons/hour), dosage (grams) for every 57 liters of pure water, dosing method.

Add to the pre-filter and raw water pump with a dosing machine, adjust the dosing machine flow rate to about 2.5 liters/hour.

Note: If it is groundwater, surface water, or concentrated water reuse, double the amount of flocculant in the dosing tank. Multiple = turbidity / 5.

3. Adding scale inhibitor

When the raw water hardness is 50-100 mg/L (calculated as calcium carbonate), the scale inhibitor is added according to the following method:

Pure water machine model, raw water inflow (tons/hour), dosage (grams) for every 57 liters of pure water;

Add to the multi-stage pump or high-pressure pump with a dosing machine, adjust the dosing machine flow rate to about 2.5 liters/hour;

Note: If the raw water hardness is greater than 100 mg/L, double the concentration of scale inhibitor in the dosing tank.

Multiple = hardness / 100, but the maximum cannot exceed 10 times.

How to improve the repeat metering accuracy of the pump when the outlet of the metering pump is at atmospheric pressure ?

Installing a valve spring on the discharge valve of the metering pump can improve the repeat metering accuracy, but the most effective improvement is to install a back pressure valve at the end of the pipeline.

How to adjust the back pressure valve

1. Do not exceed the maximum working pressure of the metering pump.

2. When the metering pump has pressure at the suction end, the pressure at the discharge end of the pump must be at least 1 bar higher than the pressure at the suction end.