Roots vacuum unit is used for physical refining of rice bran oil. It has the advantages of low operation power, low protection cost, sensitive and inconvenient device, high production efficiency and good economic efficiency. The waste oil produced has reached the standard of four grade refined rice bran oil. The device is suitable for small-scale physical refining production line.
During physical refining, the vacuum pressure is less than or equal to 200Pa, so in the year of oil production, the water ring vacuum pump and steam water series vacuum pump can not meet the requirements. However, the operating profit of the water steam jet vacuum pump is relatively high, and it needs to be equipped with small and medium-sized steam boilers, which is not suitable for some medium-sized oil plants. Roots vacuum pump is widely used in chemical industry, such as vacuum distillation, vacuum volatilization, dehydration and crystallization, but it is seldom used in petroleum industry. In the 15t / D physical refining and deacidification line of rice bran oil, roots water ring vacuum device is equipped, which improves the production efficiency and produces a batch of qualified new national standard four grade refined rice bran oil. The device is suitable for small-scale physical refining production line.
Type, structure and working principle of roots water ring vacuum unit:
Roots vacuum pump is a kind of wound variable vacuum pump without internal pressure. It uses two 8-shaped spindles in the pump shell to produce suction and discharge effect. Indirect emission of gases into the atmosphere is not allowed. It needs to be used in series with the front vacuum pump. The extracted gas is discharged into the atmosphere through the front vacuum pump. During operation, the extracted gas enters between the screw and the pump body from the air inlet. At this time, the screw and the pump body separate the gas from the air inlet. The separated gas is sent to the air outlet during the continuous winding process of the screw.
(1) Roots pump – water ring vacuum pump. The function of the water ring vacuum pump of the unit is to create the preparation vacuum required by roots pump. Under normal circumstances, the limit vacuum of single-stage water ring vacuum pump is not high, while the vacuum required by roots pump in China is high. Therefore, in theory, it is not necessary to use single-stage water ring vacuum pump as the front stage pump of roots pump, but to use two-stage water ring vacuum pump with lower pressure limit, which can also improve the limit pressure of the unit. The limit pressure of a Roots pump and a water ring vacuum pump is 400 PA, which can meet the normal vacuum requirements, but it is limited in the physical refining process. If two pumps are connected in series and combined with water ring vacuum pump. The limit pressure of the unit can be greatly increased.
(2) When the limit pressure of the three-stage roots water ring unit cannot be met, the roots pump water ring pump series mechanical vacuum pump can be used. The device is mainly used to solve a large amount of water vapor. It has a long working time and a high vacuum, such as in dry vacuum.
The roots water ring vacuum device uses water ring pump as the pre pump, which is especially suitable for physical refining process to remove a large number of corrosive and condensing water vapor and fatty acid gas. According to the technical requirements of physical refining and the performance parameters of roots water ring vacuum device, in the process of physical refining and deacidification of rice bran oil in the year of theoretical birth, we choose two roots pumps in series, and then use two-stage pumps as the pre pump to form the device.