Two Vertical Long-Coupled Inline Pumps to replace 50 year-old pumps at a quarry
PUMPS CASE STUDY
NORTH RIDGE PUMPS
Two Vertical Long-Coupled Inline Pumps to replace 50 year-old pumps at a quarry
Our latest case study focuses on a request we received to replace two ageing pumps which had first been installed within a around 1970 .
Our client was looking to continue transferring water from ponds located on the site where it was then used for a range of processes within the quarry . This included the cooling of mechanical equipment such as saws , generators and plant equipment , as well as for the washing of sand and aggregate products like gravel and stones used in construction and landscaping .
The ponds are used because they recycle water , minimising the impact the quarry has on local water courses , and enabling the most cost-efficient operation of the plant . The pond water reused after treatment via the use of screens , and flocculation to remove contaminants .
The client ’ s existing pumps were being used to draw water from the ponds located 4.5m below the pump suction . They wanted to use their existing pipework which was DN150 outlet and DN200 inlet . In addition , they had also had problems with non-return valves on the inlet pipework , and wanted to see if these could be removed as they had failed in the past .
Vertical inline pumps can be made selfpriming through the addition of air ejectors or a separate priming pump installed on the pump head . This evacuates the air enabling the pump to perform suction lifts at up to 6m .
The client looked at both of these options . However , because of the risk of solids being caught up in the water , we could not recommend an electric priming pump , and the client was not keen on using an airdriven ejector .
At North Ridge Pumps , we ’ re not tied to a single pump technology , but provide the best pump for a particular application and designed for the lowest lifetime cost . In fact , we can use our expertise to offer a bespoke solution , not something straight off the shelf .
At North Ridge Pumps , we ’ re not tied to a single pump technology , but provide the best pump for a particular application and designed for the lowest lifetime cost .
THE VERTICAL INLINE CENTRIFUGAL PUMP DESIGN HAS MANY BENEFITS
We recommended vertical long-coupled inline pumps as they are a great spacesaving pump with a reduced footprint size . They are easy to maintain through the addition of a spacer coupling bracket , which makes it possible to access the pump head without removing the motor .
This pump design is also more robust and designed for continuous use , thanks to the extra bearing bracket installed between the pump and motor . This takes a great amount of strain away from the motor during operation .
The vertical compact design means that the long-coupled pump can be installed where there is limited space . In addition , the back pull-out design allows the motor to be removed while the pump is still connected to the pipework . This in turn means that time can be saved while the pump is serviced and maintained .
INDEPENDENT SHAFTS
On this design , the centrifugal pump and motor have independent shafts . This means that only the pump shaft will need to be replaced if it breaks . Other less robust vertical centrifugal pumps on the market only use the motor shaft . So if the shaft breaks , the entire motor needs to be replaced .
A large spacer coupling is installed between the vertical inline pump and motor . This extra space protects the motor from fluid getting in if the seal fails . In addition , wear rings can be installed in the pump head . These are sacrificial parts that wear first , protecting the impeller and casing from wear , and prolonging the life of these parts and therefore the pump .
To make maintenance and servicing easier , access to the inner parts like the mechanical seal and impeller is done by simply removing the outer cover screen on the spacer coupling bracket . Then the pump and motor shafts can be separated without taking the motor out .
The pumps were specified for transferring pond water at a rate of 319m ³ h , and around 50m head at a speed of only 1400rpm making the pumps ideal for operation for long periods .
The motor specification required operation via VFD , as well as twin wired thermistors and insulated bearings . Due to the motors being 75KW and working in conjunction with a VFD , the insulated bearings prevent the circulation of current through them which can damage them and contribute to their failure .
If you have any application needing the transfer , circulation or injection of viscous solid-laden liquids and aren ’ t sure which pump to specify , speak to North Ridge Pumps to see how we can help .
For further information , please visit www . northridgepumps . com
118 PECM Issue 64