Sanitary pumps are classified according to the occasions where they are used. Specifically, they involve the transportation of all products that come into contact with the human body, such as pharmaceuticals, dairy products, beverages, food, cosmetics, food additives, and fine chemicals. According to different classification standards, sanitary pumps can be divided into many types
1. Classification by working principle
Centrifugal pump
Working principle: Use centrifugal force to throw out the liquid, with the characteristics of large flow and high head. Centrifugal pumps are divided into single-stage centrifugal pumps and multi-stage centrifugal pumps. When a single-stage centrifugal pump is working, the liquid fills the pump casing, the impeller rotates at high speed, and the liquid generates high speed under the action of centrifugal force. The high-speed liquid passes through the gradually expanding pump casing channel, and the dynamic pressure head is converted into static pressure head. Compared with a single-stage pump, the difference between a multi-stage centrifugal pump and a single-stage pump is that a multi-stage pump has more than two impellers, which can absorb and pressurize water in multiple stages in sections, thereby lifting the water to a very high position. The head can be increased or decreased according to the number of pump impellers as needed.
Advantages: simple and compact structure, small size, light weight, good processability, low price, strong self-priming force, insensitive to oil contamination, wide speed range, able to withstand impact loads, easy maintenance, and reliable operation.
Disadvantages: Unbalanced radial force, large flow pulsation, high noise, low efficiency, poor interchangeability of parts, difficult to repair after wear, and cannot be used as a variable pump.
Positive displacement pump
Working principle: It transports liquids through volume changes and has the characteristics of precise measurement. Common positive displacement sanitary pumps include plunger pumps, rotor pumps (cam pumps), peristaltic pumps, diaphragm pumps, etc.
Plunger pumps: transport liquids through the reciprocating motion of the plunger.
Rotor pumps (cam pumps): Suction is generated by synchronous reverse rotation, and then used to transport materials. At the same time, the rotor chamber is divided into multiple small spaces. When a space is filled with medium, the next space will be immediately closed. Through this process, the material can be transported in a cycle. Suitable for transporting media with high viscosity and sensitive materials.
Peristaltic pump: relies on rollers to squeeze the hose to transport liquids, without leakage and pollution, suitable for occasions that require gentle treatment.
Diaphragm pump: uses the reciprocating motion of the diaphragm to inhale and discharge liquids, suitable for corrosive and high-viscosity liquids.
Jet pump: uses the jet principle to transport liquids.
Air delivery pump: used to transport air or gas-liquid mixtures.
Vortex pump: uses the rotation of the impeller to generate a vortex to inhale and discharge liquids, suitable for occasions that require mixing or dispersion.
Magnetic drive pump: transmits power through magnetic coupling, eliminates the risk of shaft seal leakage, and is suitable for occasions that require pollution-free transportation.
2. Classification by functional characteristics
Self-priming pump: can automatically inhale liquid, suitable for liquids containing gas or gas.
Multistage pump: used in applications that require higher head.
Screw pump: suitable for the transmission of high-viscosity media, with soft and hygienic characteristics.
Shear pump: also called "emulsification pump", is a sanitary pump with multiple functions such as dispersion, homogenization, emulsification, and homogenization.
Sine pump: a rotary positive displacement pump, also known as a rotary positive displacement sine pump. Due to the interaction between the inclined scraper door and the dynamic rotor, the medium is gently conveyed through the uniquely designed rotor, with low pulsation and no impact.
Roots vacuum pump: Due to the continuous rotation of the rotor, the pumped gas is sucked from the air inlet into the space between the rotor and the pump housing, and then discharged through the exhaust port.
There are many types of sanitary pumps, and the selection needs to be comprehensively considered based on specific application requirements, medium characteristics, flow rate, head, working environment and other factors.