The working process in a double-acting piston pump in which the valves have been replaced by fl uidic diodes is investigated. A computational model of the process, constructed on the basis of a representation of a complex stream by a sum of two simple streams, the fi rst caused by the harmonic movement of the piston and the second due to the head difference between the dampers, is proposed. Analytic expressions of the fl ow-head characteristics and the pump effi ciency are obtained. It is shown that, unlike a piston pump with valve distribution, the fl ow-head characteristic of a pump with fl uidic diodes is descending and fl attened. In the region of low heads, its delivery may exceed the delivery of a pump with valves. There is an interval of heads on the characteristic in which the effi ciency of the pump is maximal. Keywords: piston pump, valves, fl uidic diode, computational model, dimensionless parameters, fl ow-head characteristic.The use of piston pumps with valve distribution [1] in the chemical, medical, and food industries represents a diffi cult process in view of the undesirable effect of the tools of these hydraulic machines (for example, valves) on liquid. In addition, as a consequence of the comparatively low degree of reliability of valves and the slowness of the parts of a valve mechanism, piston pumps are generally slow-running and of high metal content [2].Theoretical and experimental studies of valveless piston pumps [3] have investigated the force pump, or T-junction, in the central diffuser of which a piston that has been set in motion by a crank-gear mechanism and by an inlet and an outlet damper, travels. A dependence of the pump head on the frequency of the to-and-fro motion of the piston and a number of geometric parameters has been proved by numerical and experimental investigations.A micro-pump the discharge element of which comprises a membrane with piezoelectric drive has been investigated [4] with diffusor-confusor possessing diodicity provided for the purpose of implementing the distribution function [5][6][7][8][9][10]].An analytic model of the working process in a pump with vortical fl uidic diodes is presented in [11]. The tool in this pump was not a piston or membrane (as in [3,4]), but instead a gas which is alternately supplied to the pump cylinder and discharged from it. A description of such a pump is presented in the manual [12]. The device is characterized by the authors as a highly reliable pump of the type used predominantly in the nuclear industry.Thus, valveless piston pumps are effi cient and, if fl uidic diodes are used, the indicators of such pumps improve noticeably. The objective of the present study is to determine the basic parameters and characteristics of a valveless hydraulic machine (Fig.1).The block of cylinders comprises a block of one, two, or more single-acting or double-acting pistons. The calculation of the characteristics of a valveless pump is performed here for the case of a single-cylinder, double-acting pump (Fig. 2).
Among hydrodynamic machines, jet pumps are among the most common. The high demand for this type of pump is due to their following features: the absence of moving parts and the simplicity of the device, small overall dimensions and weight, high self-priming ability, the ability to pump aggressive media and hydraulic mixtures containing solid impurities. In the hydromechanical method of developing deposits of building materials (sand, gravel, etc.), jet pumps – hydraulic elevators are used for underwater mining and transportation of bulk materials to the sorting plant, and after classification of the sand-gravel mixture – hydraulic transport of sand and gravel to dumps through pipelines. With this method of laying the finished product, the jet pump creates a static pressure of the hydraulic mixture, sufficient for its transport to the dump. However, another way of laying the finished product in dumps is also possible – through the air with a slurry stream. In this case, the jet pump performs the function of a hydrometer – a device for creating a high-speed slurry jet. A review of the literatureshowed that this mode of operation of the jet pump was not investigated. The effective operation of the jet pump-hydrometer depends on the ratio of the areas of the outlet section of the nozzle and the normal section of the mixing chamber, the relative density of the slurry in the input hopper. For each value of the relative density of the slurry, there is an optimal ratio of the areas of the nozzle and the chamber at which the specific energy consumption of the active stream will be minimal. The aim of this work is to determine and analyze the characteristics of an ejection hydrometer and to identify the most effective modes of its operation.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.