Generally speaking, the standard pumping capacity of paper production line is certain, but in order to reduce energy consumption and production cost, the selection of vacuum pump is particularly important. For paper industry, roots vacuum pump is usually used instead of water ring vacuum pump. Therefore, comparing the economic benefits of Roots vacuum pump and water ring vacuum pump is the main problem of paper manufacturers. Of course, this will also involve the choice of Roots vacuum pump.
Today, I will introduce you to the application and selection of Roots vacuum pump in paper industry. In the process of pulp and paper technology, vacuum dehydration can be used in the dehydration process, and roots vacuum pump is a common method of paper dehydration.
Vacuum dehydration is a common process in papermaking industry. Vacuum pump is used for vacuum dehydration. The specific process is very complex, which is a typical case of vacuum dehydration. The specific process flow of the process is described in detail below.
The general technological process of papermaking is as follows: raw material – slicing – Cooking – washing – Screening – bleaching – beating – vacuum dehydration (using vacuum pump) – squeezing dehydration – drying – forming – leaving the factory.
The pulp after beating contains a lot of water, so the water in the pulp must be removed to make the finished product. Vacuum dehydration is the first stage of pulp dehydration.
The process of vacuum dehydration is to spray the pulp into the fine grid of copper mesh woven from copper wire. A vacuum box is set under the copper mesh belt every certain distance, and a vacuum pipe is connected under the vacuum box, and then the air inlet pipe of the water ring vacuum pump is connected.
Due to the vacuum caused by vacuum pump, the water in the pulp on the copper mesh can be sucked into the pipeline to achieve the purpose of dehydration.
When the roots vacuum pump is selected, when the pumping capacity meets the requirements of the production line, the working point shaft power of Roots vacuum pump can be reduced as much as possible. When the power consumption of Roots vacuum pump is very small, the production cost of pulp and paper will be lower. If the power of the motor is also small, the cost of electrical configuration can also be controlled.
In the papermaking process, vacuum dehydration is required:
1. Brown pulp washing machine
A vacuum can be generated inside the drum shape of the gasket, which allows the material to adhere to the drum surface and allows the black liquor to be washed out of the material when the drum is operated in the slurry.
2. Sediment filter
The sediment filter in pulp and paper mills is a horizontal drum filter, which creates a vacuum inside the drum to collect particles from the green liquor.
3. Vacuum dehydrator
The vacuum dehydrator can be used for dehydration of raw material preparation stage. It is a kind of horizontal drum filter, which can realize the proportion dehydration of pulp and improve the concentration of raw materials.
4. Headbox compressor or vacuum pump
The headbox compressor or vacuum pump is used in the slurry tank. Through a series of valves, pressure or vacuum can be added to the raw material tank of the headbox to control the material discharge rate.
5. Water suction tank
The suction box is applied to the forming part of the paper and can be directly dehydrated from the pulp. Roots vacuum pump is used to produce vacuum conditions in the vacuum tank of the suction tank.
The couch roller is an important dehydration part in the paper forming stage, and has a rotatable porous shell which can have one or two vacuum areas.
7. Vacuum pressing
The vacuum press mechanically extracts water from the paper. The paper machine usually has one or three pressing areas, when the paper is transported and padded, the moisture is pressed into the pressing blanket.
8. Blowout preventer
The windproof box is fixed before the paper is transferred, and can be used to generate a vacuum in the upper area of the pressing section. Vacuum pump is widely used in papermaking industry. Roots vacuum pump has good performance in this industry.
The above is a detailed description of the application of Roots vacuum pump in the dehydration and drying of Roots vacuum pump pulp. To learn more about the vacuum pump, please pay attention to the EVP vacuum pump manufacturer’s website.