03 May Dosing Pumps – Dosing Pumps in Water Treatment

Dosing Pumps to Facilitate Water Treatment

Water is a vital resource for humans, not only for its consumption but also for a variety of industrial processes and the production of goods. Our activity changes its natural state and contaminates it causing serious environmental damage to rivers and seas and excludes its use for activities such as agriculture. This is why we must ensure the correct treatment of water so that it can be reused and returned to the environment.

Water treatment is any process that improves the quality of water to make it usable for a specific end. This may be for purification of drinking water, industrial water supply, irrigation, river flow maintenance, or many other uses, including being safely returned to the environment.

In order for the process to work effectively, dosing pumps are used as they are designed to pump a very precise flow rate of a chemical or substance into either a water, steam or gas flow.

When Should Dosing Pumps be Used?

Dosing pumps, also referred to as chemical handling pumps, should be used when you have an application that requires liquids to be metered into other processes at a finite and accurate rate. A chemical dosing pump is often used to add a caustic chemical or an acid to a water tank to neutralise the PH level. It can also be used as a chlorine pump to kill bacteria. Agriculture, dairy farms, horticulture, breweries, power generation and oil and gas industries rely heavily on them to ensure that the correct chemical-to-liquid ratio is met.

The Types of Dosing Pumps Used in Water Treatment

There are four different types of dosing pumps that can be used for a variety of water treatment applications.

• Diaphragm Constant Injection – the chamber is emptied and filled through a piston action and has a diaphragm as well as inlet and outlet valves. When the chamber is full, the dosed volume is injected out at a constant flow rate which is generally between 6 and 250 litres per hour.
• Diaphragm Pulse Injection – this employs a diaphragm mechanism and the pump is controlled by a solenoid coil that sucks in and injects the chemical in pulses. The time gap between the pulses regulates the flow rate. This type may not be completely accurate but it is preferred due to its simplicity (both mechanically and electrically) and its cost.

Diaphragm chemical dosing pumps are mainly used for PH balancing, boiler water treatment and coagulation and flocculation applications.

• Lobe Pumps – the design of these allows for the flux to be passed through a set of mesh gear-type impellers. Due to the volume rate passing between these impellers not being as accurate as other diaphragm pumps, and the impellers being susceptible to wearing, these pumps work to their full potential only when the flux is highly viscous and self-lubricating.

Lobe dosing pumps are used in hygienic processing industries, including food and beverage processing and biopharmaceutical manufacturing.

• Peristaltic Pumps consist of a flexible semi-circular cross-section tube to carry the product. They provide a reliable and simple solution for moving almost any fluid in a wide variety of applications. As the pump mechanism can be quickly changed out if it is contaminated or damaged, it is the choice for industries like chemical processing, water applications and the food and beverage industry. They can transfer, dose and meter out a range of fluids such as lime milk in mining applications and sodium hypochlorite at water treatment plants.

Peristaltic dosing pumps are used in water and wastewater treatment, pharmaceutical production, chemical handling, heart/lung machines during surgery and engineering and manufacturing, to name a few.

The Importance of Dosing Pumps for Effective Water Treatment

Water treatment in industry is used to optimise most water-based industrial processes, such as heating, cooling, processing, cleaning and rinsing, so that the operating costs and risks are reduced. Poor water treatment lets water interact with the surface of the pipes and vessels that carry it and can lead to contamination. Agricultural water treatment ensures that quality water is supplied, whether it is for drinking, livestock, irrigation or conveying fresh produce.

Prochem Chemical Pump Manufacturers have been in the industry for over 30 years and our expertise in the field ensures that our customers are provided with professional and independent advice when choosing the right dosing and chemical handling pumps. Contact us for more information on our various products and services available.