Paper mills use water ring vacuum Analysis

Paper mills use water ring vacuum Analysis

1, the gas entrained runoff control problems

Negative impact in the papermaking process water from the gas entrained over water ring vacuum pump performance may cause the greatest. To ensure the normal operation of the water ring vacuum pump, during the work must be the appropriate choice of pre-gas-water separator gas entrained strict control runoff.

However, the technical staff of the domestic mills gas-water separator pre-selection does not pay attention, often combined with a plurality of vacuum-point pre-gas-water separator in order to save costs, some small manufacturers will not even use the pre-air-water separator device. If each point different vacuum vacuum in the absence of water separated will be merged together, mutual interference will occur, resulting in poor air and water separation, loss increases along the way, the water ring vacuum pump performance degradation, not to mention the use of a pre-gas-water separator. In addition, the domestic machine manufacturers to provide machine-related parameters are often inaccurate or incomplete, to the pre-air-water separator is not a small selection of reasonable difficulty. In actual use, the staff of the mill on the front of the gas-water separator is not enough emphasis on the use of surveillance, as long as the pump can still meet the job requirements, pre-gas-water separator is working, very few people care about. So many domestic mills are present in the pre-vacuum system gas-water separator is invalid or poor use of effects and beyond the reasonable control of gas entrained runoff problems, resulting in decreased water ring vacuum pump efficiency.

2, the water ring vacuum pump water volume adjustment problems

When the water ring vacuum pump wet end use, from the suction port and seal at both water into the pump, to not consider whether these two approaches come through water pump performance will cause other effects of these water after entering into the mix who will pump water ring, increasing the thickness of the water loop and become part of the work of water. Therefore, in regulating the amount of water from the pump to be considered at the suction port and seal to the water. Of course, the amount of water coming from the seal of the few, mainly on account of entrained gas coming from the water pump. In no other way to reduce the inflow of gas entrained case, only the appropriate transfer of small amounts of water pumps, water ring thickness close to normal as possible, to avoid serious overload phenomenon. Therefore, the water ring vacuum pump mill to adjust the amount of water used can not just look at the amount of water given by the manufacturer values, you can "try breaking the law" to adjust the suitable water site. This is done when the pump is started, the first to open a large valve, then slowly transfer a small amount of water to the vacuum is unstable, then a little bit of water to the big pullback for the best work of water.

It must be noted that the entrained gas coming from the suction channel and the water pump water inlet coming from the water is not the same. With flat pumps, for example, shown in Figure 1, from the mouth into the water pump to pump water inflow into the gap between the first distribution plate and impeller driven impeller, bypassing distribution on the plate, play a role in the sealing gap between the distributor plate and the impeller. And from the suction port to pump into the water inflow from the suction port with the gas directly into the water ring pumps crescent-shaped working chamber of clearance between the impeller hub and distribution panels do not work well seal Therefore, when the vacuum pump work transfer of small water supply tray to a certain extent, since the gap between the impeller and the distributor plate can not be sealed, the distributor plate into the vent hole partial "short circuit", will lead to decreased volume, degree of vacuum can not be improved phenomenon. And because the intake port into the water might cause the deterioration of the performance of the vacuum pump, the shaft power-up and heat increase, coupled with its temperature from the suction port of the water is relatively high, so the pump body temperature will be higher, resulting in "Supplementary water shortage, "the illusion. If you increase the water supply, improve the sealing effect, the vacuum may be picked up, but the shaft power will be seriously overweight. This phenomenon require a higher degree of vacuum dehydration volume is large working point, such as suction couch roll, a suction press roll or the like will be more prone, because the requirements of a high degree of vacuum sealing requirements also mean a point higher. It is understood that there are many domestic mills are present this "can not be adjusted," the problem, because the plant layout has been set, and the production process can not just shut down for rectification, so difficult to solve.