How to choose the vacuum pump for carving machine? Here are a few key points.
I. normal temperature working medium (0-50 ℃), pure water pumping or solution, without water and gas dual-use, but with self-priming capacity and requirements for flow and output pressure.
It is clarified that the working medium of pumping is water, non oil, non strongly corrosive liquid and other solutions (without solid particles, etc.), so it is necessary to have self-priming function.
II. Normal temperature working medium (0-50 ℃), water pumping or gas demand (possible water gas mixing or idling, dry running occasions), vertical volume, noise, continuous use and other functions.
Clarification: it is required that water and gas can be used for both purposes, dry running for a long time without damaging the pump, continuous running for 24 hours, small volume and low noise, but not high flow and pressure requirements.
1. Use a micro pump to pump air or vacuum, but sometimes liquid water will enter the pump cavity.
2. The micro pump is required to be able to pump both air and water.
3. Use a micro pump to pump water, but sometimes there may be no water to pump, which is in the "dry running" condition.
Some traditional pumps are afraid of "dry running", "dry running" and even damage the pump. WKA series of products are essentially a kind of composite function pump, which integrates the functions of vacuum pump and water pump. Some people call it "vacuum pump". Therefore, in the absence of water, it will vacuum, when there is water, it will pump. Whether it is pumping or pumping, it belongs to the normal operation field, so there is no "dry transfer" damage.
4. It is mainly used to pump water with micro pump, but it is not expected to add "water diversion" manually before pumping (some pumps need to participate in some "water diversion" manually before operation, so that the pump can pump up the water at the lower place, otherwise the pump cannot pump water or even damage), and it is expected that the pump has the function of "self-priming" at present. At this time, PHW and WKA series products can be selected. Their benefits lie in that when they are not in contact with water, they vacuumize, form a vacuum and then rely on air pressure to raise the water pressure, and then start pumping.
3. High temperature working medium (0-100 ℃), such as using micro water pump for water circulation and cooling, or pumping high temperature, high temperature steam, high temperature liquid, etc., it is necessary to use micro water pump (high temperature type):
1. The temperature is between 50-80 ℃, the high temperature medium type of WKA series of micro water gas dual-purpose pump can be selected, and the maximum temperature resistance is 80 ℃ or 100 ℃;
2. If the temperature is between 50-100 ℃, it is necessary to select WKA series high temperature medium type, and the maximum temperature resistance is 100 ℃;
IV. there is a large demand for flow (more than 20 L / min), but the medium contains a small amount of oil, solid particles, residues, etc.
Elucidation: in the medium to be pumped,
1. It includes a small number of soft solid particles with small diameter (such as fish manure, sewage sludge, residue, etc.), but the viscosity should not be too large, and it is better not to have the surrounding materials such as hair;
2. It is allowed that the working medium contains a small amount of oil (such as a small amount of oil floating on the sewage surface), but not all of it is oil!
3. Large flow requirements (more than 20 L / min):
The vacuum pump of engraving machine should pay attention to the following matters during normal operation:
1. The new equipment is easy to have impurities, and the impeller and pump shell will be damaged in the suction pump.
2. The device shall be level and firm, and the pipeline shall not be pressed on the pump.
3. When the pump is opened, there should be a certain amount of circulating liquid in the pump cavity (the liquid accounts for 2 / 3 of the pump cavity volume, which should not be too much or too little), otherwise it is easy to form mechanical seal damage.
4. The water supply method is best to use closed-circuit circulation system or water tank to supply water steadily and normally, and it is not allowed to use positive pressure water supply or tap water pipeline.
5. Select circulating liquid with good fluidity and little influence of temperature (water is the best circulating liquid).
6. Check the bearing regularly to avoid equipment damage due to oil shortage.
7． 泵排气口的管路不得高于1米 （从法兰口算起）。
7. The pipeline of the pump exhaust port shall not be higher than 1 m (calculated from the flange port).
8. When there is explosion sound in the pump cavity, it is clarified that the limit vacuum has been reached and cavitation occurs. At this moment, the air inlet valve shall be opened to enter a proper amount of atmosphere.
9. Pumps equipped with motors above 11kw shall be equipped with step-down motors.
10. When the pump stops running, it is necessary to close the valve at the inlet of circulating water into the pump. In winter, the circulating water in the pump cavity shall be vented.
11. The operating environment temperature of the equipment shall not be too high, and the equipment shall not be exposed to the sun.