What Is a Circulating Pump?
Circulating pumps are used for moving liquids in various settings, ranging from small-scale applications like home tropical fish tanks to large-scale uses such as water purification tanks. These pumps are essential in urban infrastructure, ensuring the movement and recirculation of liquid from storage tanks to filtration systems and other destinations.
Uses of Circulating Pumps
Circulating pumps have diverse applications across household and industrial settings. Key uses include:
- Cooling water circulation in cooling towers
- Chemical circulation in scrubbers
- Pure water circulation in water-tube boilers
- Water storage and filtration in swimming pools
- Pumping mineral spring water in spas
- Aquaculture water tanks
- Water filtration systems
- Dialysis and artificial heart systems
Principles of Circulating Pumps
Most circulating pumps are electric motor pumps, often incorporating centrifugal pumps. Components include the impeller, casing, and rotating shaft. The motor-driven shaft rotates the impeller, creating pressure to move liquid. Besides centrifugal pumps, piston and diaphragm pumps are also used.
Types of Circulating Pumps
Different types of circulating pumps are designed for specific applications:
- Piston Pump: Uses a piston to drive valves, suitable for high-pressure applications.
- Diaphragm Pump: Moves a diaphragm to create pressure, known for low leakage risk. Air-powered versions are available.
- Volute Pump: A centrifugal pump variant, ideal for circulating large volumes of liquid.
Other Information on Circulating Pumps
1. Selecting Circulating Pumps for Hot Water Heating
Important factors include head (the height the pump can elevate water) and flow rate. These determine the pump’s suitability for heating systems, considering piping resistance and heat output requirements.
2. Relationship Between Heat Exchangers and Circulating Pumps
Circulating pumps are often paired with heat exchangers in systems like air conditioners and water heaters. The pump size is chosen based on the heat exchanger’s required flow rate and pressure.
3. Circulating Pumps in High-Rise Buildings
In tall buildings, pressurized circulating pumps are used to move water from storage tanks to upper floors. For buildings with many floors, intermediate pumps may be used to maintain pressure.