Use this URL to cite or link to this record in EThOS: https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.743436
Title: Three-stage turbine pump
Author: Blackadder, W.
Awarding Body: University of Edinburgh
Current Institution: University of Edinburgh
Date of Award: 1923
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Abstract:
Consultation of publications on the testing of centrifugal pumps seems to show that while much experimental work has been carried out, yet the work has been confined mainly to overall tests. Overall tests of a pump may show slight changes in efficiency with alterations in the proportions of one component part of the pump, but it is not possible to make definite conclusions as to whether this change is entirely due to the alteration in that one part of the pump. For new conditions of flow introduced by the alteration in proportion may affect the efficiency of and the losses in other component parts. A change in curvature of impeller blades or in the rate of change of cross sectional area of the passages between the impeller vanes - without alteration of the angles or radial areas at entry or exit - may affect the actual angle of discharge from the impeller tip and hence also the losses in the guide passages; and thus the change in overall efficiency may not be due entirely to the alteration in the impeller. The total losses in the pump at any delivery may be known but their allocation among impeller, guide.passages etc., is very much a matter of conjecture from analogy with results from flow through stationary passages; and in the case of shock loss, deductions from such analogy are very uncertain. Experiments were carried out by Dr. Stanton on the efficiency of a vortex chamber with and without guide vanes and with various types of impellers; and this seems to be the only published record of experiments carried out to determine separately the efficiency of a certain component part of a centrifugal pump. The experiments described in the present paper were undertaken primarily to determine the separate losses and efficiencies of the impellers, guide passages, volute, and the various connecting passages of a turbine pump, and how these losses and efficiencies varied with the discharge and the impeller speed. But during the analysis of the results it was found necessary to consider other questions. For the ordinary theory of the centrifugal pump, while indicating the general .laws connecting discharge, head, speed and power and explaining the effect of various factors in design, is admittedly not quite in accordance with actual test results as regards the relative proportions of these items. The additional matters considered are, the amount of leakage, the pressure in the casing at the side of the impeller, the manner of flow through the impeller, and the relation of the ordinary theory to the experimental results. In addition, the pump tested presents a peculiarity in the abrupt rise (with increasing discharge) of the head quantity curve at constant speed. (See Fig. 9). Additional tests were therefore made at the discharge at which the abrupt rise takes place( termed the "critical" discharge hereafter); the results have been analysed and a possible explanation of this detrimental feature put forward.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (D.Sc.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.743436  DOI: Not available
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