How to Choose The Right Head For Chemical Pumps?

When purchasing chemical pumps, if the flow and head can not be determined, then it is not possible to correctly choose the right model, when customers in the chemical pump selection, usually we will ask the user how much flow and head requirements? There are a few customers who do not have clear goals, and now we remind our customers that this practice is not possible, the flow can be without requirements, but the head can not be without requirements, and we have to tell us the actual working conditions such as vertical height, horizontal distance, how to arrange the pipeline, the number of elbows, the size of the pipeline, what liquid to convey, etcOnly then can we choose the right chemical pump for you.

First determine the specific model of corrosion-resistant chemical pump, determine the series of chemical pump and, you can choose the flow rate according to the maximum flow required by the actual working conditions, if the head is not determined, you can add elbows and horizontal distances according to the vertical height of the conveying, the pipeline loss can calculate the required head, and the value after amplifying 5%-10% margin is the required head, These two performance parameters are determined on the type spectrum or series characteristic curve to determine the specific model.

Using the characteristic curve of the corrosion-resistant pump, find the required flow value on the abscissa, find the desired head value on the ordinate, mark the perpendicular and horizontal lines from the two values up and to the right, and the intersection of the two lines falls exactly on the characteristic curve, the pump is the pump to be selected, but this ideal situation is generally not rare.

The following situations usually occur:

1. The intersection point is above the characteristic curve, which indicates that the flow rate meets the requirements, but the head is not enough, at this time, if the head is similar, or the difference is about 5%, it can still be used, if the head is different a lot, then choose a pump with a larger head. Or try to reduce the loss of pipe resistance.

2. The intersection point is below the characteristic curve, in the pump characteristic curve fan-shaped trapezoidal range, it is preliminarily determined this model, and then according to the difference in head, to decide whether to cut the impeller diameter, if the head difference is very small, do not cut, if the lift difference is very large, according to the required Q, H, according to its ns and cutting formula, cut the impeller diameter, if the intersection point does not fall within the sector trapezoidal range, should choose a pump with a smaller head. When selecting a pump, sometimes it is necessary to consider the requirements of the production process and select different shapes of Q-H characteristic curves.

For example, to transport liquid to a container that must maintain a certain liquid level, where the flow rate changes greatly and the head change is small, a pump with a flat H-O curve should be used.

For example, if the oil is sent to the tube heating furnace, if the flow rate changes in the working is small, the coking phenomenon is easy to occur in the furnace tube. To avoid this situation, when the flow rate is slightly reduced, the pressure of the oil in the pipe has a large increase, so that the scorch scar just formed is washed away by the higher liquid flow pressure, at this time, it is advisable to choose an oil pump with a more descending Q-H curve. Consider choosing horizontal centrifugal pumps, vertical centrifugal pumps and other types (pipeline, right angle, variable angle, angle, parallel, vertical, submersible sewage pump, vertical sewage pump, easy to disassemble, submerged sewage pump, non-clogging type, self-priming pump, gear oil pump, oil-filled submersible electric pump, water-filled temperature type, etc.). The horizontal pump is easy to disassemble and assemble, easy to manage, but the volume is large, the price is more expensive, and it requires a large floor space; Vertical pump, in many cases the impeller is submerged in water, can be started at any time, easy to automatically or remotely controlled, and compact, small installation area, cheaper price.