Modified atmosphere packaging (MAP) is widely used in sausage products industry. The vacuum used to empty the air in packaging is produced by the central vacuum system. It provides vacuum for all packaging lines before adding protective gases to the packaging. The best economic benefit and efficiency can be achieved by using this central vacuum supply system.
The central vacuum system consists of four rotary vane vacuum pumps. They are connected to vacuum tanks and can maintain a constant vacuum of 150 millibars. Of the four vacuum pumps, at most three need to work, and the last one remains standby. Even at full load, the system uses only three vacuum pumps. The vacuum system runs on demand, that is, the rotary vane vacuum pump is running according to the actual work needs of the vacuum pump. In daily processing, full load operation is rare, only when all four packaging production lines are equipped with the largest packaging tools and the production cycle is the same. Generally, only two vacuum pumps are working, and the maximum rotary vane vacuum pump with pumping speed up to 400 cubic meters per hour can often provide basic load. Compared with the decentralized vacuum supply, 83,000 kWh of electricity will be saved, which is equivalent to halving the energy consumption.
EVP vacuum pump is very rugged and durable. It has never been faulted. Even if one of the vacuum pumps fails, the supplementary operation of four vacuum pumps will not lead to interruption of operation. The upstream vacuum tank provides a constant vacuum of 150 millibars, which ensures that the vacuum can be pumped in the shortest time and speeds up the production cycle of the packaging process. In addition, the central vacuum supply system can realize maintenance during operation. Maintenance personnel do not need to enter the hygiene sensitive area, just go to the engineering room on the floor where the system is located. During maintenance, each independent rotary vane vacuum pump can be closed separately without affecting vacuum degree or pumping speed.
All installed vacuum pumps are specially designed for oxygen treatment and can safely compress more than 21% oxygen. Using vacuum chamber, the gas mixture with about 70% oxygen content can be added to the modified atmosphere packaging (MAP). This mixture of gases with high oxygen concentration is easy to explode. In the normal packaging process, the packing room should be ventilated after filling the gas mixture. During the next packaging cycle, only normal air needs to be removed to prevent explosion. Only in rare cases of valve failure or other damage can the concentration of oxygen entering the vacuum pump increase when the vacuum pump is pumped out. Therefore, the installed rotary vane vacuum pump model meets the highest safety requirements and can be safely removed even when the oxygen concentration increases.
Vacuum system has the following advantages:
Vacuum supply is extremely stable and reliable
Maintenance during system operation