Chemical metering pumps are utilized in a wide range of industrial applications. For instance, in water treatment, they are employed for iron sequestration, coagulation, and disinfection. In wastewater treatment these pumps are used for enhanced primary clarification, odor control, solids conditioning, phosphorus control, and disinfection. Chemical metering is also used food processing, pilot plants, paint manufacturing, car washes, greenhouses, and golf courses. Metering pumps are relied on in these arenas because they are positive displacement chemical dosing devices that can manually or automatically vary capacity and have high levels of repeatability and are able to pump a variety of chemicals such as bases, acids, viscous and corrosive liquids, and slurries.
Typical conditions where chemical metering pumps are used include those where high accuracy feed rate is required, high system pressure exists, low flow rates in mL/hr or GPH are required, corrosive, hazardous, or high temperature fluids are handled, dosing is controlled by computer, microprocessor, DCS, PLC, or flow proportioning, the metered chemical is relatively expensive, and viscous fluids or slurries need to be pumped. Due to the action or mechanism involved many pumps have pulsation effects. These include peristaltic pumps, diaphragm pumps, piston pumps, and gear pumps to a lesser degree. Pumps that demonstrate very little or no pulsation effects would be progressing cavity pumps and rotary lobe pumps.
When it comes to chemical metering pumps, there are some helpful process control strategies. Documenting a technically-based operational strategy that is somewhat similar to, but different from an O&M manual is always a good idea. Next, listing the tankage and other equipment to be used will help narrow down a specific treatment objective such as iron sequestration or phosphorus control. Create instructional guides and reference materials for operators to be used in training. Look at the interrelationship between two or more processes. Each of these can be helpful in establishing smooth running operations in terms of chemical metering pumps.