Closed – loop vacuum pump instructions

Warning
There is dangerous voltage in the operation of the equipment, any wrong operation may lead to personal injury and property loss.
The instructions in this chapter and on the product label must be strictly observed.
Maintenance must be carried out by qualified personnel.
The equipment must be cut off and grounded before maintenance.
Only approved parts can be used during maintenance.
The maintenance cycle and the replacement of parts shall be strictly observed.

1. Closed – loop vacuum pump working and preparatory conditions

The air leaked into the condenser of the power plant will
Reduce its work efficiency. Before the condenser is put into use (evacuation operation) and during operation (maintenance operation), the leaking air must be removed.

Vacuum pumps are used for this purpose.

Before the closed-loop vacuum pump is delivered for use, the operator must carefully read the operation manual. We are not responsible for any loss or damage caused by not reading the manual carefully.

The repair and replacement within the warranty period can only be carried out with the consent of our machinist. If there is any difference between the actual working condition and operation data and the data when placing the order, please contact us, otherwise the original guarantee is invalid.

2. Closed – loop vacuum pump description and function introduction

The closed-loop vacuum pump mainly includes pump and three-phase motor, separator, heat exchanger, chassis, and pipeline.

The function of the pressure switch is to enable / disable the standby vacuum unit.

The function of the differential pressure switch is to open the system inlet valve under the predetermined differential pressure.

When the condenser is connected, air is drawn into the vacuum pump through the pipeline from flange interface n1.1, and the system inlet valve is opened at this time.

The check valve is used to prevent air from returning to the system when the vacuum pump stops suddenly.

The air carries part of the working fluid of the vacuum pump, which is discharged to the separator from the vacuum pump through the exhaust pipeline. In the separator, air and water are separated. The air has been compressed to atmospheric pressure and discharged from the system through flange port n2.2.

The separator is equipped with liquid level gauge, liquid level switch, vent valve, overflow pipeline, make-up water solenoid valve and bypass valve.

Through flange interface n3.3 and water make-up solenoid valve, fresh water is added to separator and vacuum pump until the specified level is reached.

The liquid level in the separator is indicated by the liquid level gauge, and the normal liquid level is limited between the maximum and minimum liquid level marks. The level switch controls the action of the solenoid valve. When the liquid level is lower than the normal position, the liquid level switch sends out a signal, opens the solenoid valve and starts to make up water, until the liquid level reaches the normal level, the liquid level switch controls the solenoid valve to close. When the liquid level exceeds the maximum liquid level, the liquid level switch sends out a signal alarm.

The overflow line drains the excess water through the line.

The drain valve is used to completely drain the water from the separator.

The heat exchanger is drained through the vent valve, and the vacuum pump is drained through the vent valve.

The working fluid is used to form the water ring of the vacuum pump. The working fluid flows into the heat exchanger from the separator through the pipeline, and returns to the vacuum pump through the pipeline after cooling. In this process, the heat generated by compression and the heat brought in by the extracted gas are released.

The temperature and pressure of working fluid are monitored by thermometer and pressure gauge on the pipeline respectively.

3, Closed – loop vacuum pump installation

The closed-loop vacuum pump is equipped with all internal pipelines and chassis as shown in the outline dimension drawing. The lifting equipment can only be lifted by four hooks welded on the side of chassis frame, and it is not allowed to lift through internal pipelines or other points. Avoid rapid movement during lifting and landing.
The foundation is made of concrete or steel structure. The bearing capacity shall be consistent with the unit weight. The grouting port shall be reserved for the concrete foundation.

After the unit is installed, it is necessary to readjust and tighten the bolts. Readjust the motor and vacuum pump to ensure coaxiality, because slight deviation may occur during transportation.

Misalignment can cause uneven operation and damage to the coupling. The clearance on the whole coupling flange circumference must be consistent and concentric, with the maximum allowable deviation of 0.1mm. The actual deviation shall be measured and recorded twice a year.

After moving, check whether all bolt connection points are correctly installed in place. After adjusting the maintenance work, the bolts may be loose. If necessary, tighten them. The pipelines connected with the vacuum pump shall not be applied with the tension and stress of the vacuum pump. These pipelines shall be supported or suspended at first to prevent the load from being transferred to the feed ring vacuum pump.

External vibration and vibration, such as those transmitted from the plant to the vacuum pump, shall be eliminated by adding anti vibration plate.

When installing and welding around the vacuum pump, the vacuum pump must be properly protected. All unconnected interfaces shall be covered with protection to prevent external pollutants (such as tools, residual electrodes, welding slag, welding balls, dust, etc.) from entering the vacuum pump. Because these substances may damage the parts in the vacuum pump when the pump is running.

The supply and discharge pipelines will be connected with the following flanges (see the interface table for dimensions):

N1.1 gas inlet of closed-loop vacuum pump
N2.2 gas outlet of closed-loop vacuum pump
N3.3 supply and supplement of working fluid
N4.6 total evacuation
N5.0 cooling water supply
N6.0 cooling water discharge
N7.0 compressed gas supply

Before connection, all pipe sections at the factory installation site shall be cleaned, or filter shall be set at the vacuum pump inlet in the first few weeks of start-up operation.
All electrical wiring and interfaces shall comply with relevant regulations of local management department.
Except for the main drive motor, all electrical parts are connected with the junction box.

4. Closed – loop vacuum pump commissioning

4.1 preparation

Check according to the flow chart and dimension chart to ensure that the pipeline and vacuum pump are installed correctly in the whole layout.

Before starting the vacuum pump for the first time, always turn the vacuum pump shaft by hand or other suitable tools.

The rotation direction of the vacuum pump shaft shall be tested by inching the motor to ensure that it is consistent with the direction of the arrow marked on the vacuum pump. Before doing this work, loosen the packing gland slightly and then tighten it. The exhaust port must be fully open. In addition, the stop valve of the pressure gauge and the differential pressure switch of the pressure switch must also be opened and the valve must be closed.

Working fluid must be supplied to n3.3 interface and cooling water to n5.0 interface.

Before the first test run, about 4 weeks after the start-up and after a long shutdown, the vacuum pump shall be cleaned with clean water (soft water), which is very important.

4.2 water injection of vacuum pump

Inject working fluid into the closed-loop vacuum system through flange interface n3.3 (if necessary, open 242 bypass valve to accelerate vacuum pump filling). At the same time, the water level in the water filling separator of the vacuum pump is increased through the pipeline, heat exchanger 130 and the pipeline, and the water filling process is completed when the water supply of the make-up solenoid valve is stopped. The water level in the separator can be monitored by the level gauge and rechecked after about 5 minutes (at this time, the balance has been established).

4.3. Start up.

Start the motor, open the cooling water valve and the system inlet valve at the same time, and the vacuum pump will be put into operation. When the water ring is erected, the system will enter the working state.

4.4 stop

1) Stop the drive motor of vacuum pump
2) Close the inlet valve at the suction end to ensure the specified starting state.
3) Close the cooling water valve.

After shutdown, the liquid level between the vacuum pump and separator is automatically balanced through the working liquid pipeline. When the vacuum pump needs to drain, all relevant drain outlets must be opened.

Note: if you want to stop for a long time (1 month or longer), you must empty the water in the vacuum pump.

Closed – loop vacuum pump instructions