How to best choose Wastewater Pumps

When selecting a wastewater pump, consider the application constraints and features needed in a pump system. If easy maintenance is of the essence, choose a self-priming or dry-pit installation. If cost is an obstacle, submersible pumps will allow for a more compact installation. The pumps you see today and highly advanced so it helps no end to choose one that takes some of these aspects fully into consideration. It also helps for the buyer to have a clear grasp too of what it is they so require.

The type of material in the fluid should be considered when selecting a proper pump for wastewater treatment. Fluid streams within a wastewater treatment plant are characterized by their properties as follows: large solids, grit, sludge, scum and flocculated materials. The wastewater fluid stream may contain one or more of these characteristics. These properties will create different considerations that need to be addressed when selecting a pump for the intended service. Therefore, the user should identify and communicate to the pump manufacturer the nature of the fluid for each specific application.

In general

Generally wastewater pumps are required to handle solids. Rotodynamic pumps that are specifically designed to deal with solids and minimize clogging are referred to as solids-handling pumps. Solids may include household and commercial solids, large solids, stringy material (such as rags and hair), sanitary waste, plastic scraps, food waste, sticks, leaves, abrasive materials (such as sand, grit, stones and pieces of metal), and other inorganic and organic solids.

Solid materials that have recently become more prevalent in wastewater flows are: personal wipes, towels, cleaning cloths and household cleaning materials that are marketed to be discarded through the sewer system. These materials, in addition to the stringy materials and rags, can bind together to create a large mass that can lead to clogging issues in the pump and associated piping.

What you also need to be aware of

Water is one of the most important elements for any industry. Be it paper manufacturing, sugar processing, chemical industries or more, water serves many purposes in the business / industrial plant. And, this essential element is becoming more and more scarce. This means, industries have to look for ways to reuse water, thereby reducing the burden on the environment. Once water has served its use, it needs to be collected and dispatched to the wastewater treatment plant.

A wastewater treatment plant is one that treats used water and makes it suitable for other applications. In the treatment plant, wastewater flows through the system. Sometimes, wastewater has to be moved opposite to gravity. In such instances, you require a pumping station and pumps to create a stable and smooth flow of the wastewater throughout the treatment plant.

How to choose the ideal wastewater pump

Here’s a quick look at the factors you have to consider while choosing a wastewater pump. They are as follows;

• Minimum energy use
• Maximum pumping reliability
• Aesthetically pleasing design (it has to be invisible)
• Features that deal with odour (mostly hydrogen sulphide)
• Intelligent control systems
• The pumps must suit even challenging pump station layouts

Replacing your pump

If you’re replacing an old effluent pump, you can typically use the same horsepower that you had before. That said, you should also pay close attention to the GPH or gallons per hour rating as they can vary by horsepower. If your pump wasn’t keeping up, you may need to upgrade to a higher horsepower so it can keep up.

If you were able to get several years of service out of your old pump, chances are that it’s the right horsepower to choose. You may also wish to stick too with the same manufacturer of the pump you may already also have. It may be easier to stick with who you are with that look for a new supplier from scratch. This can after all prove to be tiring process in getting familiar with new ways of working and getting used to a whole new pump model and design.

Being aware of the nature of a waste water pump

Wastewater can be both corrosive and abrasive. To ensure reliable and cost-effective pump operation, it is important to select a wastewater pump made from the most suitable material for your wastewater. After all, this is also much different in terms of how it works to say a beverage pump or a medical pump – it needs to be robust and able to handle heavy loads too. Overall, you need to make sure the pump is made and built to a strong overall technical standard for the best use for the end user.

How do you size a water pump?

For commercial or industrial systems, the average solids size is 2 ½” or larger. Flow and total dynamic head (TDH) are integral in selecting a pump. Your water flow requirements, measured in GPM, are based on the number of people using the system, peak usage times and the number of water fixtures (e.g. toilet, sink).

Sludge pumping

Sludge pumping applications can contain stringy material, grit and grease and may be viscous in consistency. Some sludge can also contain a significant volume of entrained gases, such as hydrogen sulfide, due to organic bacterial action. The pumps should address these characteristics and minimize the potential for clogging and gas binding. Scum is commonly present in stormwater pumping and similar applications.

Scum consists of all of the floatable materials that are skimmed off the surface of primary and secondary clarifiers. This can consist of any materials that are light enough to float on the water surface. Scum normally consists of oils, grease, fats, wax, soaps, food wastes, hair and light plastic materials. The scum is removed from the clarifiers and sent to the digester or dewatering system.

Conclusion

Overall, in terms of how it is they work and function, pumps need to be able to handle flocculated materials. Pumps that transfer flocculated materials (smaller particles that have agglomerated into larger particles) need to keep the material in the flocculated state and not shear it. Flocculated materials are normally associated with clarifiers where the lighter solids have been flocculated to aid in their removal from the process.