LANDSCAPING SERVICES
SELECTION OF BOOSTER PUMPS FOR IRRIGATION
Sizing of Pumping Systems for irrigation is not for guess work and to select well , needs many considerations to achieve optimum performance and efficiency .
Head and flow are the main requirement for any system , however there is a lot of information required to get the best efficiency and reliability .
Head is seen as the highest point of discharge from the pumps , but we need to understand the total amount of static head and other head losses in the system to define the Total Head . Pipework costs may push installers towards using less costly small-bore mains to the discharge points , only to undermine the long-term energy cost and system performance . Unfortunately , the friction loss within a small-bore irrigation system will demand more energy , escalating the running costs for energy , therefore the more flow the larger bore pipework is required , especially for the main distribution pipework .
Other losses are found in any pipework system and should be accounted for when calculating the total head , sprinklers , irrigators , fittings , valves will have an identified head loss valve and by careful selection and design some of these losses can be reduced .
Once the total head and flow has been determined the process of selecting the pumping system can begin , most facilities such as golf clubs , sports grounds , parks , large gardens will require a system using 2 or more pumps with a ‘ jockey ’ pump to cope with small fluctuations in pressure demands .
The control of these pumps is via an electrical control system which will monitor the pressure with the discharge water main and will start the pumps as demand increases , so one pump may be required initially , but as demand increases an additional will be deployed to maintain pressure .
The control systems , maybe as simple as using mechanical pressure switches , to activate the motors via crude ‘ direct online ’ starting methods , however more commonly , variable speed drives are being used to match performance with demand giving better overall performance and economy .
A reliable and efficient control system will have a myriad of additional built in protection features supplementary to the expected motor overload protection ; dry running protection is essential to avoid damaging the pumps due lack of incoming water , equally under pressure protection may be provided which shuts the system down if there is a delivery main burst or unplanned discharge beyond normal planned flows occurs .
Power supply is a very important consideration , ensuring that there is sufficient supply to meet the demand of a new system , while location of system is important trying balance the best location of the pump set to optimise the irrigation obligations but not too far from a main power supply to avoid escalating costs of larger power cabling to avoid voltage drop which will undermine the system .
Recent examples of diverse booster pumps installations for irrigation show how different applications can be applied successfully .
Golf Course As part of a wider water management scheme on a
Hertfordshire golf course , this required a booster set meeting very high industry standards , to improve the distribution of water around the expansive course where the water was extracted from lake .
A Dual Booster Set was sized and selected , complete with 2 x 5.5kW vertical multistage pumps , motor mounted variable speed drives and bespoke control panel to Irritech specification , including back up fail-safe system via Digital Pressure Controllers . The pump set in a duty / assist configuration , will achieve a performance of 20m ³/ hr at 8.8 bar pressure .
The booster set is used daily to water the main pitch at the bet365 stadium .
Football Stadium The home of Stoke City FC , the bet365 stadium , as with all major sporting grounds , requires watering daily to keep their pitch in a premium condition . Searching for an efficient and economic product that could provide reliable irrigation with automatic control . The system , comprised of fixed and variable speed clean water multistage pumps , was designed and manufactured to provide both the flow and water pressure required for the football ground .
Talk to the experts at TT Pumps Ltd Tel + 44 ( 0 ) 1630 647200 . www . ttpumps . com
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