Sump Slurry Pump Commonly Used Flow Adjustment Method

Centrifugal Slurry Pumps are widely used in water conservancy and chemical industries, and its selection of working conditions and analysis of energy consumption are also receiving increasing attention. Usually, the flow rate and pressure head of the centrifugal pump may be inconsistent with the pipeline system, or the flow rate of the pump needs to be adjusted due to changes in production tasks and process requirements. The essence is to change the operating point of the centrifugal pump. In addition to the correctness of the centrifugal pump selection in the engineering design stage, the choice of the operating point of the centrifugal pump will directly affect the user's energy consumption and cost. Therefore, how to properly change the operating conditions of the centrifugal pump is particularly important.

AH series Slurry Pump works by converting the mechanical energy of high-speed rotation of the motor into the kinetic energy and potential energy of the lifted liquid. It is a process of energy transfer and conversion. According to this feature, the operating point of the centrifugal pump is based on the balance between the energy supply and demand of the pump and the pipeline system. As long as the situation of the two changes, the operating point will shift. The change of the operating point is caused by two aspects: 1. The characteristic curve of the pump itself changes, such as impeller cutting. 2. The piping system characteristic curve changes, such as valve throttling.
 

Centrifugal Slurry Pumps

The following two methods are analyzed and compared:

First, the impeller cutting

When the speed is constant, the pressure head and flow rate of the pump are related to the diameter of the impeller. For the same type of pump, the cutting curve can be used to change the characteristic curve of the pump. It is assumed that the original impeller diameter of the centrifugal pump is D, the flow rate is Q, the lift is H, the power is P, the diameter of the impeller after cutting is D', the flow rate is Q', the lift is H', and the power is P'. :

The above three types are collectively referred to as the cutting law of the pump. The cutting law is based on a large number of inductive test data. It is considered that if the impeller cutting amount is controlled within a certain limit (this cutting limit is related to the specific number of revolutions of the pump), the corresponding efficiency of the pump before and after cutting can be regarded as constant. Impeller cutting is a simple and easy way to change the performance of the pump. The so-called variable diameter adjustment solves the contradiction between the limitation of the pump type and specification and the diversity of the requirements of the water supply object to some extent. The scope of use. Of course, impeller cutting is an irreversible process, and the user must perform accurate calculations and measure economic rationality before implementation.

Second, valve throttling

The easiest way to change the Sump Slurry Pump flow is to adjust the opening of the pump outlet valve, while the pump speed remains the same (typically rated speed), which essentially changes the position of the line characteristic curve to change the operating point of the pump. When the small valve is closed to control the flow rate, the water supply capacity of the pump itself is constant, the lift characteristic is unchanged, and the pipe resistance characteristic will change with the change of the valve opening degree. This method is easy to operate, continuous flow, and can be adjusted freely between a certain maximum flow rate and zero, and no additional investment is required. However, the throttling adjustment is to maintain a certain amount of supply by consuming the excess energy of the Centrifugal Slurry Pumps, and the efficiency of the centrifugal pump will also decrease, which is not economically reasonable.

Nowadays, the preferred adjustment method for many enterprises is impeller cutting, because the impeller cutting can save energy and reduce consumption, but it must be accurately calculated before the impeller cutting can be carried out to ensure that the impeller can meet the working conditions after cutting.