Paper machine problem _ in selection of the vacuum system arrangements

in general, less than - vacuum range 15 kpa, can consider to choose single stage centrifugal fan instead of vacuum pump. Compared with the water ring vacuum pump, exhaust machine is small in size, low price, high efficiency. The choice of the materials and structure of the exhaust machine moist environment conditions should be considered and soda mixture and features. Don't in the gas into the exhaust machine with too much water. Otherwise it will affect the normal operation and lead to the fan exhaust machine vibration. Therefore, before the exhaust machine also has separator installation. Separator is separation of fine fiber and to reduce the scale of the fan blade.

according to the distribution of vacuum points to determine the number of vacuum pump is a very important work, directly affect the paper machine of papermaking, paper quality, working efficiency and water and electricity consumption, etc. Under normal circumstances, paper machine supplier will provide the mature solution, design institute will also be fully considered. Need to pay attention to the following:

( 1) Each blanket during the use of different times have different permeability and different life. At work, should be adjusted according to the state of each rubber cloth vacuum degree, in order to achieve the required service life. As a result, each blanket are equipped with independent special vacuum pump is the best choice.

( 2) With partition of water ring vacuum pump can work in two vacuum area, that is, a pump can be used as two pumps and does not interfere with each other.

( 3) It is best not to at a two vacuum pump working on net and squeeze. Net and squeezing vacuum points should be separated as much as possible. In the process of start of the paper machine, first open the network department, then stability in pulp after open the squeezing and squeezing vacuum. If you open the squeezing vacuum cleaner, can cause a lot of damage to the carpet.

therefore, vacuum pump can be divided into network of vacuum pump and vacuum pump pressure.

in the papermaking workshop, a slight vacuum water pump, but because of containing fine fiber, proportion is very serious, serious impact on the quality of the paper, such as use full stainless steel pump investment index will increase, so consider using the common materials and anti-fouling processing. Nash pump, for example, the use of pump body diene rubber lining, Kenfu water pump body anticorrosive coating processing, some lined with stainless steel plate, make the water pump inside sleek, not easy to scale. No matter manufacturers use which kinds of preservatives, must be the mature technology manufacturers. After put into use, spray coating or stainless steel plate should not fall off, this will result in more serious consequences.

4 auxiliary equipment. 1 pre separator and negative pressure of white water pumps

pre separator is located in the vacuum pump and dehydration between components, there are two kinds of forms, with negative pressure pump, there is no negative pressure pump, no prior cyclone separator with and baffle type of vacuum pump. Usually, when the paper machine is installed on the second floor of workshop. When the vacuum degree is less than or equal to 45 kpa, can be used without negative pressure pump separator.

4。 2 sealing water filtration equipment

loop contains fine fiber and vacuum packing water, if not filtered, will accumulate more, affect the vacuum system of pump and cooling tower. In the choice of filtering equipment, usually choose curved sieve, tubular filter, gravity filter, etc.

4。 3 cooling tower

even if the vacuum water be filtered before entering the cooling tower, there are still many fine fiber, fine fiber accumulation in the cooling tower packing, this will affect the cooling effect, but can be compressed when packing, debris into the system, the consequence is very serious. During the period of choice can choose type sewage cooling tower in order to avoid the consequences.

4。 4 choose white pumps

vacuum pump water from the pit to cooling tower, because water for 3 ~ 4 m. If the use of common centrifugal pump, the suction below the liquid surface in the impeller, and the need to fill the water in advance at the start. Suction pipe need equipped with bottom valve, can not meet the requirement of the production process. Therefore, choose the self-priming pump or submersible pump. High cost of self-priming pump, submersible pump operation reliability is low, need high maintenance space. In order to achieve the goal of common self-priming water pump, we can be installed on the common centrifugal pump inlet pipe or the guide tank, simple structure, convenient operation, reliable operation. Conclusion

paper machine vacuum system is a complex system, in the normal running of paper machine plays a crucial role. At the same time, it is a major consumer of water and electricity. Only correctly configured to optimize the vacuum system vacuum pump and auxiliary equipment. In order to improve the reliability of equipment operation, reduce the production cost, improve the economic benefit.