It is nearly as fast as the one of UG at the run-velocity. Test results show that it works quite stable in finish-machining impeller channel with Al alloy at a spindle-speed of 5 000 r/min and a feed-rate 600 mm/min. Accordingly it is very beneficial for high speed machining.
This paper discusses the pressure exceeding problem at the second stage exit of CO 2 centrifugal compressor in urea plant after long period of running and gives countermeasures The main reason for this problem is the scaling of high pressure cylinder impeller channel while the direct cause is the sulfur containing CO 2 gas and ammonia containing water used to wash the CO 2 gas To adjust the operation style according to the scaling degree of the rotator can effectively control and reduce further generation of the scale
The design principle of complex impeller of lowspecificspeed,lowtemperature and highspeed centrifugal pumps is derived according to relative velocity distribution in impeller channel. The design rules and the empirical formula of blade numbers are given.
Through analyzing the operation conditions of compressors and pumps in service in the refinery plant of Daqing Petrochemical Complex, factors that restrict the total efficiency of compressors and pumps such as pump outlet valve throttling and motor power too big, etc. are found out, and energy-saving improvement measures of blocking impeller channel, turning the outside diameter of impeller and replacing energy-saving motors are recommended, thus saving electricity 412 500 kWh/a.
In order to research the hydraulic designmethod of splitting vanes, for the first time puts forward the computation method for blade number on the basisthat negative velocity should not come into being in the flow passage.
Experimental investigation of the internal flow field of rotating impeller passage with inlet box
Using PDA and its measurement system, the flow fields at the different peripheral locations of rotating impeller passage of a diagonal fan with inlet box are measured.
The results are compared with the flow field of the rotating impeller passage of the same fan without inlet box.
The periodic unsteadiness is due to the distortion of the flow in the peripheral direction at the exit of the centrifugal compressor impeller, caused by the jet-wake type of flow discharging from each impeller passage.
It is revealed that impeller A achieves higher effective head than impeller B even though the flow patterns in impeller A are more complex, exhibiting secondary flows and reverse flows in the impeller passage.
Topological analysis of the formation of Jet-Wake flow pattern in centrifugal impeller channel
The reason for this could be found in the fact that in the simulation was made only for one impeller channel.
Such hydraulic features as the velocity circulation of a fluid in the impeller duct, curl of the fluid motion, and the potential flow of the fluid flowing in the vaneless zone of the impeller, are discussed. Theoretically, a new concept is proposed that the absolute motion of a fluid in the duct of a rotating impeller is rotational and so is the following motion, but the relative motion is ir-rotational.
The features of oil-film and paint prescriptions are investigated in this paper. Two paint prescriptions of polyamine resin which can be used for flow-visualization in hydraulic maching are given. Oil-film pattern in extremity clearance of guide vane of water turbine inside of the impeller of centrifugal pump are obtained by using this kind of paint priscription
A new method to generate 3-D body-fitted coordinate system for the channels of centrifugal impellers was described. The coordinate system is generated by solving a number of 2 -D elliptical partial differential equations. Comparing with the method directly solving three 3-D elliptical partial differential equations for body- fitted coordinate systems, this method can save much computer time and storage. An example of coordinate generation for a centrifugal compressor impeller was given.