Correspondence between Flow Rate and Head of Multistage Pump

Category: Water pump knowledge

2024-07-12

multistage pumpIs a commonly used fluid conveying equipment, widely used in water supply, industrial circulation, agricultural irrigation and other fields, flow and head are two important performance parameters of multi-stage pump, there is a close correspondence between them.

Flow rate refers to the volume or mass of liquid delivered by a pump in a unit of time, usually expressed as cubic meters per hour (m³/h) or liters per minute (L/min). The lift refers to the energy that the pump can provide when conveying the liquid, which is expressed as the pressure increase obtained by the liquid under the action of the pump, and its unit is meters (m).

The relationship between the flow and head of the multistage pump can be summarized as follows: at a certain speed, the flow of the pump increases, and the head will decrease accordingly. This relationship is mainly determined by the design structure and internal flow characteristics of the pump. As the number of stages of the multi-stage pump increases, it can provide a higher head, but at the same time the flow will be affected. This is because each stage of the impeller in the liquid transfer process will produce a certain pressure loss, with the increase of the number of stages, the pressure loss will accumulate, thus affecting the flow.

The basic principle of 1. multistage pump

The multi-stage pump is composed of two or more than two single-stage pumps, and the output of a single-stage pump is used as the inlet of another single-stage pump, and finally a multi-stage pump with high head and high flow rate is formed. According to its structure, multi-stage pumps can be divided into two types: multi-stage centrifugal pumps and multi-stage plunger pumps.

Multi-stage centrifugal pump is a centrifugal pump that uses centrifugal force to accelerate liquid. Due to the limited head of single-stage centrifugal pump, it is necessary to improve the head by multi-stage series. The flow head table of multi-stage centrifugal pump shows an upward trend, that is, the flow rate decreases and the head increases.

The multistage plunger pump is a positive displacement pump that uses the plunger to reciprocate in the cylinder to suck and discharge the liquid. Due to the limited diameter of the plunger, the flow rate needs to be increased by multistage parallel connection. The flow head table of multi-stage plunger pump shows a parallel trend, that is, the flow rise head is unchanged.

Corresponding Relation between Flow Rate and Head of 2. Multistage Pump

There is a close relationship between the flow size of multi-stage pump and its head, and there is a corresponding relationship between the two. The first thing to know is that the value of the flow of the multi-stage pump is determined by the flow of the basic single-stage pump and the number of single-stage pumps, and the head of the multi-stage pump is determined by the sum of the head of the single-stage pump.

Theoretically, there is a certain mutual restriction between the flow and the head of the multi-stage pump. Among them, the flow rate of the multi-stage pump decreases with the increase of the head, while the head of the multi-stage pump decreases with the increase of the flow rate. In practical applications, we need to select the appropriate multi-stage pump model and number of pump heads according to different working environments and needs.

Matters needing attention in the use of 3. multistage pump

1. The multi-stage pump should be installed correctly according to the operating instructions before use.

2. After the multi-stage pump is not used for a long time, the medium in the pump body should be cleaned and maintained.

3. When using the multi-stage pump, attention should be paid to maintaining a proper and stable working current and voltage.

4. During the use of multi-stage pumps, it is necessary to regularly check the damage of the internal parts of the pump body and replace them in time.

5. In the process of using multi-stage pumps, care should be taken to avoid injecting high concentrations of chemicals or physical particles into the pump to avoid unnecessary damage to the equipment.

Typical parameters of 4. multistage centrifugal pump

1. Flow rate: The total flow rate of the multi-stage centrifugal pump depends on the number of stages designed and the flow rate of each stage.

2. Head: The total head of the multi-stage centrifugal pump is equal to the sum of the heads of each level, that is, the head increases with the increase of the series.

3. Power: The total power of the multi-stage centrifugal pump is equal to the sum of the power of each level, that is, the power increases with the increase of the number of stages.

4. Efficiency: The efficiency of a multi-stage centrifugal pump is equal to the ratio of total head to total power, which changes with the change of flow and head.

In practical applications, the correspondence between the flow rate and the head of the multistage pump needs to be selected according to the specific working conditions and requirements. In general, the performance curve of the multi-stage pump will indicate the head value under different flow rates, or the flow value under different head. These performance data can help users choose the appropriate pump model and configuration according to actual needs.

In addition, the correspondence between the flow rate and the head of the multi-stage pump is also affected by other factors, such as the physical properties of the liquid (such as viscosity, density, etc.), the speed of the pump, the diameter and number of the impeller, etc. Therefore, when selecting and using multi-stage pumps, these factors need to be considered comprehensively to ensure that the performance of the pump meets actual needs.

In short, there is a close correspondence between the flow rate and the head of the multi-stage pump, which is affected by many factors such as the structure of the pump, working conditions, and the nature of the liquid. When selecting and using multi-stage pumps, comprehensive consideration needs to be made according to actual needs to ensure that the performance and efficiency of the pump reach the best state.

Previous: Guide to repair and maintenance of multistage pumps in the power industry

Next: There is a positive proportional relationship between the lift and the series of stainless steel multistage pumps

Contact Us

Free Hotline:+86 18142662779

Fixed telephone:+86 19313001794      

Mobile:+86 18142662779(WeChat/WhatsAPP)

E-mail:info@sanchangpump.net