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:
Benefits, drawbacks and operational issues:Operational issues
Actuators:Construction of pneumatic cylinders.
System selection considerations:Power requirements and Influence of conveying distance.
Air flow rate evaluation:The influence of temperature and Conveyed material influences.
Gas–solid separation devices:Separation devices and Gravity settling chambers.
THE COMPRESSOR:COMPRESSOR CLASSIFICATION AND SELECTION.
Optimizing and up-rating of existing systems:System not capable of duty
Optimizing and up-rating of existing systems:Optimizing existing systems
Review of pneumatic conveying systems:System requirements and Multiple pick-up
Material property influences:Dense phase sliding bed flow
Conveying characteristics:Energy considerations and The influence of conveying air velocity.
HYDRAULIC FLUIDS:PURPOSE OF THE HYDRAULIC FLUID
Hydraulic pumps:Vane pumps.
Gas laws.
ENTROPY:THE ENTROPY CHANGE OF IDEAL GASES