If the liquid you’re pumping contains solids, there are a number of solids handling submersible pumps that might be appropriate for your application. To avoid clogs or burning your motor out, you need to make sure you have the right pump. There are key questions that help determine which pump will solve your problems. In this post, we’ll examine these questions so that you’re prepared when you talk with your provider.
What type of solids are you’re pumping?
Understanding the solids in your liquid helps your provider determine the right type of pump for your application. We’re focusing on wastewater, so we can assume your solids are not abrasive (abrasive solids would require a hard metal, agitator pump). Most likely, they are large and soft or long and stringy. You also need to know if the solids need to be reduced to go into your system or to discharge, or if you just need to pass them.
Large and soft solids generally need a shredder pump that will shear the materials before pumping. Long, stringy solids indicate that you’ll need a vortex pump that can pass the entire solid.
Understanding the type of wastewater is also helpful. These are generally categorized as municipal (including sewage) or industrial. While municipal wastewater is generally consistent among sites, industrial wastewater solids and contaminants often vary based on industry.
What solids loading can the pump handle?
There needs to be enough liquid either in the sump or in the system to keep solids moving with the liquid. Without enough water, the pump will clog and won’t be able to pass the solids. Most solids handling pump designs can handle approximately 5% solids by volume. If your wastewater has a higher concentration, you will likely need to add more water to the sump by changing the system to allow more water to accumulate in the sump or by adding more water to the process.
The sump pump basin size is also a factor. The basin should be sized to minimize the number of cycles per hour but cannot be so large that solids will settle instead of being brought into the pump.
How might your piping system affect the pump you need?
Understanding the design of your piping system will help your provider make sure there are no areas where the solids may settle, build up and cause clogs. This includes:
- Size of the Piping: It must be large enough to pass solids downstream, but small enough to maintain carrying velocity to prevent solids from settling out. We recommend carrying velocity of 5-7 ft./sec. for municipal wastewater applications. As the specific gravity of the solids increases, you may need to further increase the velocity to carry the solids.
- Vertical Lift: This is the height that water has to travel as it moves through your piping system. A significant vertical lift combined with an improperly sized pump can cause solids to recirculate and clog within the pump volute.
- Location of Check Valves: The check valves should be as close to the pump as possible. If too far from the pump or too high, solids can build up before reaching the valve. This causes clogging as the solids backflush into the pump. Adjusting the location of the check valve generally solves these issues.
In some instances, your provider may conduct an inspection. If the entire piping system isn’t visible, you may need to show the piping system plans or explain where and how far the piping goes. The piping connections and fittings are important too.
What is the required flow rate for your system?
The flow rate is the amount of liquid that runs through the system in a given amount of time. This and the pipe sizing determine the velocity needed to pass the solids downstream through the pipes. The flow rate also indicates the appropriate size your sump should be. An undersized sump causes the pump to cycle too frequently and burn itself up.
If you don’t know your flow rate, here are two options to help your pump provider determine it:
- Calculate the flow rate by performing a draw down test. With no water entering the sump, allow the current pump to run for as long as possible while recording the time in operation. The flow rate is the volume of liquid pumped (sump length x sump width x the change in liquid level from start to end of pumping cycle) divided by the amount of time recorded during the drawdown test.
- If you have the model number of your current pump, researching the pump’s performance curve combined with the piping system information or a pressure gauge reading in the system can help your provider calculate the flow rate.
Translating answers to the solids handling pump you need
The answers to these questions provides the information your provider needs to make a recommendation. The natures of the wastewater and solids determine the type of pump you need (i.e. shredder or vortex pump). The flow rate (and the amount of head in the system) indicates the specific pump model you need.
In addition, you may have unique circumstances to consider, especially when dealing with harsh environments. These are the types of situations in which BJM Pumps excels. We build submersible pumps to deal with rugged applications and have 35 years of experience helping customers dealing with the issues you deal with every day. Contact us or call us at 860-399-5937 to request more information or to initiate a personalized evaluation of your submersible pump needs.
Delicate and quiet operation with Alfa Laval’s new robust Twin Screw Pump
Designed for handling fluids which are sensitive, abrasive, and either high or low viscosity, the Alfa Laval Twin Screw Pump is ideal for use in hygienic applications in the dairy, food and beverage, and personal care industries.
“The Twin Screw Pump is the ideal choice for both high and low viscosity liquids, all pumped perfectly with complete reliability,” says John Walker, Pump Portfolio Manager.
Additional benefits of the Alfa Laval Twin Screw Pump are that it is quiet and virtually pulse-free, as well as being smooth and gentle during operation. These characteristics make the pump an excellent choice for handling sensitive products.
Built on a robust, reliable platform that meets stringent hygienic standards, the pump is capable of handling both product transfer and Cleaning-in-Place (CIP). Its low pulsation characteristics and excellent solids handling capabilities reduce the risk of product damage, thereby improving product quality. Maintenance is simplified and process uptime increased.
Two-in-one operation provides easy handling of process media of varying viscosities as well as CIP fluids. This simplifies piping and pump control, cutting costs and minimizing contamination risks. Superior suction performance with excellent lift capability and low NPSHR provides installation flexibility and increases product recovery.
Service and reliability
Quick, easy seal replacement with the pump in place is made possible, thanks to a cartridge seal with a truly front-loading, self-setting design. This maximizes process uptime and minimizes maintenance costs. An optional seal service kit program adds maintenance flexibility and cuts operating costs.
The Alfa Laval Twin Screw Pump features a clean, external stainless steel finish with profiled elastomers and mechanical seals fully surrounded by the product. Designed for maximum cleanability using FDA-conforming materials, the pump is both EHEDG- and 3-A certified. An optional ATEX version enables use in hazardous zones.
Alfa Laval is a leading global provider of specialized products and engineering solutions based on its key technologies of heat transfer, separation and fluid handling.
The company’s equipment, systems and services are dedicated to assisting customers in optimizing the performance of their processes. The solutions help them to heat, cool, separate and transport products in industries that produce food and beverages, chemicals and petrochemicals, pharmaceuticals, starch, sugar and ethanol.
Alfa Laval’s products are also used in power plants, aboard ships, oil and gas exploration, in the mechanical engineering industry, in the mining industry and for wastewater treatment, as well as for comfort climate and refrigeration applications.
Pumps bring comforts to travelling Pandas
The two pandas arriving from China to Copenhagen ZOO will settle into the brand-new Panda House powered by Grundfos among others.
A technologically advanced home is waiting for the two pandas that have arrived to Copenhagen ZOO as an official gesture from China to HM Queen Margrethe of Denmark.
The 4000 square meter Panda House is designed by architect company BIG and financed by a range of Danish companies and foundations, including Grundfos.
We have supplied 15 MAGNA3 circulation pumps and one PUST pumping station to regulate heating, cooling and water, which includes a stream running through the complex.
Installation work has been carried out in cooperation with installer company C5 VVS & Ventilation A/S. For Grundfos, the project was a chance to ensure comfortable surroundings for the furry travelers in a setting, which emulates the animals’ natural surroundings.
“I am not sure we have ever delivered solutions for pandas, but together with ZOO, designers and installers, we have worked hard to ensure they will enjoy their new home. I feel privileged that we were able to back this project and contribute our knowledge and products to such a fantastic complex, designed with a great focus on animal welfare,” says Brian Sørensen, Sales Director, Grundfos.
At Copenhagen ZOO, preparations have been underway for almost 10 years. Expectations are high ahead of the grand opening of Panda House.
“Thanks to contributions from 16 large Danish companies, we have built a facility that will raise Denmark’s profile internationally for many years to come. We have had animal caretakers, zoologists and veterinarians on education in China and been in close dialogue with Chinese professionals since 2010. And we have not least a whole plantation on South Zealand with sprawling fresh bamboo. So I dare say: we are ready to accept our newest residents, because this is, in the original sense of the word, a historic event,” says Jørgen Nielsen, CEO of Copenhagen ZOO.
Symbol of friendship
Pandas are a national treasure in China, and Denmark is only the 19th country ever to receive pandas. The gesture is a symbol of friendship and trust that rings true for overall Sino-Danish relations and the special bond between Grundfos and China.
“It is very rare that pandas are sent to other countries, so this is indeed a humbling and great honor, which illustrates the excellent friendship between Denmark and China. Our involvement in this project makes perfect sense, as we have forged strong links with China over the years,” says Brian Sørensen.
MAGNA3 gets environmental certificate
In an industry first, our circulator pump now comes with an Environmental Product Declaration, documenting the product’s impact on the environment.
The footprints left by MAGNA3, in terms of energy consumption, chemical substances and emissions, have been detailed in an Environmental Product Declaration (EPD). It is the first time any pump manufacturer acquires an EPD in accordance with the European standard EN 15804.
“It is a very important step for Grundfos to be able to document towards our customers the environmental performance of our products in a standardised way,” says Mathias Høeg, Senior Life Cycle Assessment Specialist at Grundfos.
The third-party verified document, issued by independent assessors at the German Institut Bauen und Umwelt, communicates transparent, comparable information about the product’s life-cycle impact.
Having an EPD does not necessarily imply that the declared product is environmentally superior to alternatives. It simply provides facts, which are widely requested among Grundfos customers and partners.
“This area is becoming a hot topic here. As an example, with a strong focus on Nearly Zero Energy Buildings, the architect on an upcoming housing development project requires an EPD for the pumps,” says Mark O’ Sullivan, Sales Engineer at Grundfos Ireland in a sentiment echoed in various markets around the world.
More products in sight
The next step will be to obtain the EPD for even more products, which falls in line with Grundfos’ ongoing ambitions to deliver as energy-efficient and environmentally friendly products as possible and to do so in a transparent manner.
“Working with EPDs and life cycle assessment influence the way we develop new products. Environmental performance will be considered alongside other design criteria such as price and functionality. This is possible because environment as a term can now be measured and communicated in numbers and graphs,” explains Mathias Høeg.
Valves12 months ago
The tips on maining a foot valve
Genel2 years ago
Expansion Joints10 months ago
More go with better flow
Valves2 years ago
WEY new generation Knife Gate Valves by ; Sunsay
Electric Motors1 year ago
NSK develops insulated bearings for inverter motors
Pumps1 year ago
Indar, Colorado River Basin is helping to combat drought
Pumps11 months ago
BJM Expands KB Series – Larger KB220 model
Valves10 months ago
New ORBINOX knife gate valve for Water Treatment Applications