Comprehensive Guide to Chemical Centrifugal Pumps: From Features to Installation

Comprehensive Guide to Chemical Centrifugal Pumps: From Features to Installation

1.Overview of Chemical Centrifugal Pumps

Chemical centrifugal pumps, as reliable assistants in the chemical industry, have gained widespread popularity due to their outstanding performance characteristics, such as wear resistance, uniform water output, stable operation, low noise, easy adjustment, and high efficiency. Their working principle involves the generation of centrifugal force when the impeller rotates while the pump is filled with water. This force pushes the water in the impeller channels outward into the pump casing. Subsequently, the pressure at the center of the impeller gradually decreases until it falls below the pressure in the inlet pipe. Under this pressure differential, water from the suction pool continuously flows into the impeller, enabling the pump to sustain water suction and supply. With the growing demand for chemical centrifugal pumps across various industries, it is essential to delve into their technical details. Next, Anhui Shengshi Datang will explore 20 technical questions and answers about chemical centrifugal pumps with you, unveiling the technical mysteries behind them.

2.Performance Characteristics of Chemical Centrifugal Pumps

Chemical centrifugal pumps are highly favored for their wear resistance, uniform water output, and other features. They possess multiple characteristics, including adaptability to chemical process requirements, corrosion resistance, tolerance to high and low temperatures, resistance to wear and erosion, reliable operation, minimal or no leakage, and the ability to transport liquids in critical states.

3.Technical Details of Chemical Centrifugal Pumps

 a. Definition and Classification

Chemical centrifugal pumps are devices that generate centrifugal force through impeller rotation and can be classified into vane pumps, positive displacement pumps, etc. Based on their working principles and structures, chemical pumps are categorized into vane pumps, positive displacement pumps, and other forms. Vane pumps utilize the centrifugal force generated by impeller rotation to enhance the mechanical energy of liquids, while positive displacement pumps transport liquids by altering the working chamber volume. Additionally, there are special types like electromagnetic pumps, which use electromagnetic effects to transport conductive liquids, as well as jet pumps and airlift pumps that utilize fluid energy to convey liquids.

 b. Advantages and Performance Parameters

Centrifugal pumps offer high flow rates, simple maintenance, and core metrics such as output power and efficiency. Centrifugal pumps exhibit several notable advantages in application. First, their single-unit output provides a large and continuous flow without pulsation, ensuring smooth operation. Second, their compact size, lightweight design, and small footprint reduce costs for investors. Third, the simple structure, minimal vulnerable parts, and long maintenance intervals minimize operational and repair efforts. Furthermore, centrifugal pumps feature excellent adjustability and reliable operation. Notably, they require no internal lubrication, ensuring the purity of the transported fluid without contamination from lubricants.

 c. Types of Losses and Efficiency

Main hydraulic losses include vortex, resistance, and impact losses, with efficiency being the ratio of effective power to shaft power. Hydraulic losses in centrifugal pumps, also known as flow losses, refer to the difference between theoretical head and actual head. These losses occur due to friction and impact during liquid flow within the pump, converting part of the energy into heat or other forms of energy loss.

Hydraulic losses in centrifugal pumps primarily consist of three components: vortex loss, resistance loss, and impact loss. These combined effects create the difference between theoretical and actual head. The efficiency of a centrifugal pump, also called mechanical efficiency, is the ratio of effective power to shaft power, reflecting the extent of energy loss during operation.

 d. Speed and Power

Speed affects flow rate and head, with power measured in watts or kilowatts. The speed of a centrifugal pump refers to the number of rotations the pump rotor completes per unit time, measured in revolutions per minute (r/min). The power of a centrifugal pump, or the energy transmitted to the pump shaft by the prime mover per unit time, is also known as shaft power, typically measured in watts (W) or kilowatts (KW).

 e. Head and Flow Rate

When speed changes, flow rate and head vary according to square or cubic relationships. Adjusting the speed of a centrifugal pump alters its head, flow rate, and shaft power. For unchanged media, the ratio of flow rate to speed exceeds the speed itself, while the ratio of head to speed equals the square of the speed ratio. Meanwhile, the ratio of shaft power to speed equals the cube of the speed ratio.

 f. Number of Blades and Materials

The number of blades typically ranges from 6 to 8, with materials requiring corrosion resistance and high strength. The number of blades in a centrifugal pump impeller is a critical parameter directly affecting pump performance. Generally, the blade count is set based on specific applications and needs, ensuring efficient and stable operation. Common manufacturing materials include gray cast iron, acid-resistant silicon iron, alkali-resistant aluminum cast iron, chromium stainless steel, etc.

 g. Pump Casing and Structure

The pump casing collects liquid and increases pressure, with common structures including horizontal split-type designs. The pump casing plays a vital role in centrifugal pumps. It not only collects liquid but also gradually reduces liquid velocity through specific channel designs. This process effectively converts part of the kinetic energy into static pressure, enhancing liquid pressure while minimizing energy loss due to oversized channels. Common pump casing structures include horizontal split-type, vertical split-type, inclined split-type, and barrel-type designs.

With the continuous updates in process technology for chemical enterprises, stricter demands are placed on the stable operation of chemical centrifugal pumps. These pumps play a crucial role in the chemical industry, where their performance stability directly impacts the smoothness of the entire production process. Therefore, a deep understanding and rational selection of pump casing support forms are essential for ensuring the stable operation of chemical centrifugal pumps.