Liquid Ring Vacuum Pump for Vacuum Sealing
Vacuum pump is the most important equipment in vacuum pumping system for vacuum sealing moulding. According to the characteristics of vacuum sealing moulding, vacuum pumps need to have the conditions of high exhaust efficiency, less influence by dust in inhaled air, easy maintenance, low noise, and do not need excessive vacuum, generally within the range of 33.99-66.650 kPa (350-500 mmHg).
There are wet and dry vacuum pumps. Dry vacuum pump can get a relatively high vacuum degree, but its structure is complex and easy to break down, so it is not suitable for selection; while wet vacuum pump is sealed by water, which has stable performance and is not easy to break down, and can completely meet the requirements of vacuum sealing modeling, so it is more suitable.
Wet vacuum pump is also called water ring vacuum pump or water seal vacuum pump. When choosing wet vacuum pump, we should pay attention to the relationship between its pumping capacity and vacuum degree. The larger the vacuum degree is, the smaller the pumping capacity will be. Usually, the vacuum degree can be considered as 66.650kPa (500mmHg), and the amount of air pumping can be determined by the volume of the sand box and the number of sand boxes modeled at the same time.
The characteristics of liquid ring vacuum pump are simple structure and compactness; the rotor can be directly connected with the motor without speed change device; the exhaust is uniform and the exhaust volume is large; the vulnerable parts are few and the work is reliable; besides bearing lubrication, other parts need not be lubricated; but because of the existence of water and steam partial pressure in the pump, it can not produce high vacuum degree (70%~90%). The liquid ring vacuum pump is suitable for pumping gases containing liquids (especially for conveying corrosive and explosive gases).