Systems without static head or closed loop systems
The specific energy here is dependent on the frictional head loss which, in turn, is determined by the losses in the pipe system (including throttling valves), and by the combined drive-motor-pump efficiency.
The combined drive-motor-pump efficiency has to be evaluated for each duty point. It is to be noted that the pump efficiency remains approxi mately the same in a system of this type when the speed is changed, whereas the drive-motor efficiency can drop drastically as the load is reduced. If on the other hand, the system curve is changed by changing the setting of a valve, this will change the duty point of the pump and, hence, its efficiency.
Related posts:
Selection process retrofitting to existing equipment:Retrofitting a motor mounted VFD
Actuators:selection and performance of cylinders
Compressed Air Transmission and Treatment:Commissioning and safety
Air flow rate evaluation:Volumetric flow rate
Air movers:Air compression effects and Delivery temperature.
Health and safety:Conveying systems and Closed systems.
Pipeline scaling parameters:Pipeline bore and Empty line pressure drop
ROUBLESHOOTING HYDRAULIC SYSTEMS:ISOLATING PROBLEMS IN A HYDRAULIC CIRCUIT
HYDRAULIC FLUIDS:Density and Compressibility
HYDRAULIC PUMPS:Vane Pumps
Cartridge logic valves.
lime delay valves.
Fundamental Principles:IndustrIal PrIme movers
POWER AND REFRIGER A TION CYCLES: THE IDEAL CYCLE FOR SPARK-IGNITION ENGINES
FORCED CONVECTION:LAMINAR FLOW IN TUBES