The application range of water ring (water cup) vacuum pump is very wide, and the vacuum degree can exceed -30Kpa. However, due to the small air volume of a single machine, it is not commonly used in vacuum cleaning systems.

Roots blower is widely used in positive pressure airflow transportation, but usually a negative pressure value of -30Kpa or above is required in vacuum cleaning systems, and the vacuum degree of ordinary Roots blower cannot meet it.

The air ring (volute) fan has been widely used in vacuum cleaning systems, and the technology is also quite mature. It is cheap but has high heat generation. During normal operation, the shell heats up and the temperature is around 120 degrees Celsius, so the surrounding environment needs good ventilation to cool down. The upper limit of negative pressure value for air ring fans is usually -30Kpa.

Multi stage centrifugal fans usually have 5-stage or 7-stage compression and high negative pressure values. When facing high negative pressure requirements above -40Kpa, multi-stage centrifugal fans are usually selected. Advantages: A single fan has high air volume, high negative pressure value, and stable operation. Disadvantage: The price is expensive. Usually, temperature monitors and vibration monitors are required to monitor the operation status of the fan at any time. Common international brands include NASH, SPENCER, INTERNATIONAL, and so on.

1Kg (kg)=0.1Mpa (megapascals)=100Kpa (kilopascals)=100000pa (pascals)=1bar (bars)=1000mbar (millibars)
1000L/min (liter/minute)=1m3/min (cubic meter/minute)=60m3/h (cubic meter/hour)=60CMH

1.1. For example, blowing through the mouth is positive pressure, while inhaling through the mouth is negative pressure.
1.2. Therefore, when the fan blows air into the dust collector, it is a positive pressure filtration. For example, when conveying materials through airflow, most of the options are for a positive pressure system.
1.3. The fan draws air from the dust collector, which is negative pressure filtration, such as vacuum cleaning and vacuum feeding. The negative pressure system is selected.

2.1. For example, when blowing through the mouth, it is easy to blow down an empty cola bottle that is 20 centimeters away.
2.2 When inhaling through the mouth, do not lift up an empty cola bottle that is 10 centimeters away.
2.3 Therefore, the effectiveness of vacuum cleaning depends on the distance between the vacuum broom and the ground. The closer it is to the ground, the greater the suction force and the better the cleaning effect.
2.4 Airflow conveying can choose either positive or negative pressure airflow. However, positive pressure conveying is usually chosen because when the same force is generated, it can consume energy, and positive pressure is lower than negative pressure.
2.5. When conveying with positive pressure airflow, the material thickness of the shell of the dust collector is thin, while when conveying with negative pressure airflow, the material thickness of the shell of the dust collector is thick.

3.1 For example, blowing through the mouth won't break the cola bottle, while inhaling through the mouth can deflate the cola bottle.
3.2. Therefore, dust collectors used for vacuum negative pressure need to withstand pressure and prevent suction collapse, and the wall thickness cannot be cut corners.
3.3. With the same wall thickness, cylindrical boxes are more resistant to negative pressure than square boxes. Therefore, the cylinder of vacuum dust collectors is usually designed as a cylindrical shape.

4.1. When the cleaning valve is completely closed or the pipeline is blocked, the high negative pressure fan faces the risk of pressure suppression and burning.
4.2. To prevent pressure buildup, a pressure relief valve is usually installed above the dust collector or a bypass pressure relief valve is installed on the main pipeline before the fan inlet.
4.3. After instrument detection, feedback data is sent to the PLC. The PLC program makes judgments based on the feedback parameters and transmits instructions to enable the pneumatic valve to perform opening and closing actions.
4.4. When the cleaning valve is completely closed, the pressure relief valve will automatically open, extracting wild wind from the environment and releasing pressure, effectively protecting the vacuum fan.

5.1. For low concentration and non continuous cleaning, direct bag or filter cartridge filtration is sufficient.
5.2. For high concentration, multi job, and long-term continuous operations, it is recommended to use a two-stage filtration system of cyclone+bag or filter cartridge.
5.3. For those using multi-stage centrifugal fans, it is recommended to use a three-stage filtration system consisting of cyclone, bag or filter cartridge, and HEPA.
5.4. Foreign brand multi-stage centrifugal fans with high negative pressure and large air volume are often expensive, far exceeding the price of dust collectors.
5.5. Once the blades of a multi-stage centrifugal fan are contaminated with dust, over time, it will cause dynamic balance failure and face expensive major repairs.
5.6. The three-stage filtration of cyclone+bag or filter cartridge+HEPA filter results in a final emission concentration of less than 1 milligram/cubic meter, which not only protects the fan but also meets the requirements of environmental protection and unorganized emissions. It can be discharged without a 15 meter chimney.
5.7. In the mode of three-level filtration, when the second level filter material is damaged, the pressure difference monitoring value will exceed the range and be abnormal. After receiving the feedback signal, the PLC will alarm and can link to emergency shutdown. At this time, the third level filter material is responsible for high concentration interception, and the final support time for the HEPA filter to reach adsorption saturation is about 15 minutes.
5.8. By sacrificing the HEPA filter, direct dust contamination of the fan blades was prevented, the fan was protected, and valuable time was gained for discovering abnormal situations of powder leakage and handling.

6.1. If the wind speed in the pipeline is high, it can prevent dust from accumulating in the pipeline. When designing explosion-proof dust, it is required that the pipeline wind speed is not less than 23 meters per second, so the pipeline wind speed of vacuum dust collectors is usually referred to as above 23 meters per second.
6.2. The wind speed of the branch pipeline is usually above 23 meters per second.
6.3. The diameter of the pipeline connecting the suction port to the terminal is DN40mm or DN50mm, and the wind speed at the pipe mouth is usually above 50 meters per second
6.4. Prevention of electric shock: If metal dust is being cleaned, high-speed airflow will generate static electricity when rubbing against the pipe wall. At this time, copper braided tape grounding should be used to eliminate charges in the pipeline. If there is no grounding to eliminate the charge, touching the pipeline can cause mild hand numbness, and severe cases can lead to corona. Such accidents are also common.

7.1. The purpose of installing a frequency converter on a vacuum fan is to protect the fan, prevent the motor from overload and burning out, and prevent current from impacting the power grid.
7.2. The allowable frequency adjustment range for vacuum fans is very small. Exceeding this range can cause fan surging, vibration, and unstable negative pressure values.
7.3 Therefore, it is not possible to adjust the vacuum fan using the conventional thinking of variable frequency fans.

8.1.Low concentration, short duration, low dust content, usually using shutdown dust removal mode.
8.2. In the shutdown and ash cleaning mode, only the first level discharge valve is installed in the hopper. After the shutdown, the discharge valve can be opened to discharge the material.
8.3. In high concentration, long-term, and multi job conditions with dust levels exceeding multiple tons, online dust cleaning is usually used.
8.4. A two-stage lock air and ash discharge valve has been installed for online ash cleaning. When the upper level is closed, the lower level opens for ash discharge; The upper level opens the ash discharge, and the lower level closes the air lock, thus operating back and forth.
8.5. For example, when the vacuum cleaning system is used for vacuum feeding, the online cleaning mode is also adopted.

Usually, stainless steel pipes or carbon steel pipes can be used.

For example, at -30KPA, the corresponding weight is 0.3 kilograms, and using a stainless steel decorative tube with a normal thickness is sufficient. The standard for selecting tap water pipes for drainage can be used for vacuum pipelines.

3.1. The sealing requirement for vacuum cleaning pipelines should be based on the requirement of sealing the water supply pipe without leakage.
3.2. To prevent pipeline leakage, it is recommended to use full welding technology for all main and branch pipes in the pipeline.
3.3. When valve control is required in pipelines, it is recommended to use valves in drainage engineering that can seal water and also be capable of sealing negative pressure suction.
3.4. The interface for connecting the terminal to the vacuum cleaner is usually sealed with a DN40 or DN50mm tap water ball valve, which is more effective than a wall valve.
3.5. The hose for the terminal vacuum cleaner can be a civilian vacuum cleaner hose, but it is more recommended to use transparent steel wire hose, which has high strength and can be freely cut in length.

Welding steel wire mesh or a few steel wires above the suction port of the terminal pipeline can effectively prevent plastic bags and other debris from being sucked into the pipeline.

Of course. At this time, one water removal bucket needs to be configured and installed between the suction scraper and the terminal suction port. The purpose of the water removal bucket is to separate water and gas。

Of course. At this point, one debris bin needs to be configured and installed between the suction bar and the terminal suction port. There is a steel wire basket inside the debris bin, which plays a role in separating large-sized debris.

Of course, it is necessary to install explosion-proof devices such as explosion-proof discs, flameless explosion-proof devices, one-way explosion-proof valves, explosion-proof motors, etc. in accordance with explosion-proof requirements.

Of course there is. For example, the magnetic levitation fan will not be elaborated on due to limited space.