By Neumaier R.
The improvement of airtight (sealless) pumps during the last part century are traced and up to date layout options are defined. the present kingdom of the expertise is analyzed. The layout, functionality, and alertness of airtight centrifugal pumps and rotary displacement pumps are studied.
Read or Download Hermetic Pumps PDF
Best machinery books
This booklet offers a complete examine business compressors. Readers can discover a good deal of data in keeping with lengthy commercial adventure, on a transparent and well-founded method of real-gas dealing with, and on options to many functional difficulties. "Process Centrifugal Compressors" offers engineering contractors and clients of commercial compressors with a greater perception into the "how" and "why" of alternative layout good points, therefore delivering a superior foundation for facing brands.
An entire, state of the art advisor to the layout, purposes, and upkeep of valves and actuators. Todays creation strategies contain new and unique fluids, severe pressures and temperatures, and more and more subtle electrical and digital strategy keep watch over expertise. What new valves and actuators can be found to satisfy the demanding situations dealing with mechanical designers, process/control engineers, and upkeep group of workers?
Additional info for Hermetic Pumps
Canned motor pumps and magnetic drive pumps) When operating such pumps in the overload range, which can occur when pumping without throttling control, the maximum flow rate specified by the manufacturer may be exceeded, and for self-priming centrifugal pumps this can lead to thermal overload of the motor. In the case of canned motor pumps and magnetic drive pumps where no additional pressure increase of the partial flow is provided for by means of an auxiliary impeller, then an impermissible temperature rise can occur due to the smaller pressure gradient and this results in a reduction in the stator-clearance flow.
The disadvantage of this is that the required status has to be established by throttling using a gate valve or orifice. Another possibility is to return part of the flow through a bypass into the suction or supply vessel. Both these methods of adjusting the operating parameters are, however, associated with energy losses which under certain circumstances can be of an unacceptable magnitude. NB! (canned motor pumps and magnetic drive pumps) When operating such pumps in the overload range, which can occur when pumping without throttling control, the maximum flow rate specified by the manufacturer may be exceeded, and for self-priming centrifugal pumps this can lead to thermal overload of the motor.
That duty point B and the point of best efficiency coincide. As can also be seen from Fig. 10, the power input for self priming centrifugal pumps is lower up to average specific rotational speed with increasing rate of flow and reducing head. When designing the drive motor, care should be taken to ensure that no motor overload occurs with a fluctuating head and there is still adequate reserve. 1 Change in the rate of flow Q for a change in static head Hst with the hydrodynamic component remaining constant at the system head curve As can be seen from Fig.