Digestate Transfer Pump for AD plant reduces fertiliser use
An anaerobic digestion plant operator contacted North Ridge Pumps who were looking to reduce fertiliser use , and utilise digestate throughout their farm .
Digestate is an excellent fertiliser containing all the nutrients and micronutrients required for successful modern farming , including nitrogen , potassium and phosphorus . What ’ s more , none of these nutrients are lost during anaerobic digestion , so farmers can close what ’ s called the nutrient cycle and reuse these essential minerals .
What our client wanted They wanted to improve the transfer rates from their digestate pond to a nursing tank at their anaerobic digestion plant .
The liquid being transferred was mechanically-separated anaerobic digestate which contained screed at less than 1mm and only 5 % solids . The mixture also contained a small amount of sand .
They were struggling to achieve a flow rate of 100m ³ h , and wanted to double this up to 200m ³ h . The digestate transfer pipeline was 300m long and fed into a nursing tank , as well as into digestate tanks as a feedstock or seed for future batches .
They were extracting the digestate liquid from a lagoon 4m in height and 18m away . Their objective was to double their existing flow rate and hydraulically mix their lagoon , they were looking for a heavy duty transfer pump to achieve this .
What was our specification ? Here at North Ridge Pumps , our wide-ranging expertise means we can specify from a wide range of pumps for a variety of industrial and commercial applications .
Moreover , we ’ re not limited to a single pump technology . Our knowhow enables us to offer a bespoke
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Our XR pump series has design features including oversized inspection ports , and no internal screws in the pump unit .
solution , not something just picked off the shelf . This means we can select the most appropriate pump for any application at the lowest lifetime cost .
For this demanding application , we specified our XR625 , and built and supplied it in just over 6 weeks . This is a 6 ” self-priming pump manufactured from ductile iron and hard faced seal unsusceptible to solids such as sand for this application .
Our pump is designed to deliver a digestate transfer flow rate of 200m ³ h with only an 18.5Kw motor . To maximise output flow , we advised the client to run the pump at 60Hz via a frequency inverter to achieve the required flow and pressure .
Our XR pump range
These are heavy-duty self-priming pumps which are solid handling , efficient and extremely durable . This is thanks to the armoured volute which surrounds the impeller , improving pump efficiency and protecting the pump casing from wear .
What ’ s more , the XR ’ s double curved impeller helps improve pump efficiency . For example , in this particular application , the existing pump achieved a flow rate of just 100m ³ h with a 25kw motor . Our new pump delivered 200m ³ h with a motor power of only 18.5Kw .
Protected against corrosion
Another important consideration was the properties of the digestate itself . It can vary in quality and be very corrosive . So when selecting a pump type , we had to make sure that all internal parts were easily accessible and aren ’ t held in place by screws which can corrode over time .
Our XR pump series has design features including oversized inspection ports , and no internal screws in the pump unit .
Another clear advantage of our XR range is that traditionally self priming pumps have a wear plate covering the impeller which is replaced as it wears .
The issue with this design is that when the wear plate is replaced pump performance is not restored to that of the original design as the casing has worn . Our range features an armoured volute covering the impeller which when replaced ensures the pump works to the original performances .
If you have an application needing smooth transfer of fluids , viscous liquids or solids and don ’ t know which pump is best for you , talk to North Ridge Pumps and get expert help and advice .
www . northridgepumps . com