Research And Application On Cavitation Of Circulating Water Pump Of The Cooling Tower In The 300,000 MTPA Ammonia Plant

For a long time, the pump cavitation has been regarding as a difficult problem to be resolved. Cavitation of centrifugal pumps not only directly affects it's characteristic, work reliability and working life, but also affects its' system reliability and economics. As a result, in the process of designing and manufacturing centrifugal pump nowadays, cavitation property, which must be one of the important characteristic indexes, has been valued and investigated. Because of its catholicity and complexity, cavitation is positively researched all over the world. This paper starts with the cavitation and centrifugal pump lift theories analysis, not only deduces the basic equation in cavitation in centrifugal pump, but also analyses the influence of each factor on the cavitation property during the pump operation. At the same time, the paper studies the conditions for cavitation occurrence and development and its influence for water pump's outside characteristic curve, work reliability and working life.In this paper, the cavitation property of the circulating water pumps of the cooling tower in the 300,000 MTPA Ammonia Plant is studied and the improvement measures and experiment plans are given. These pumps supply directly the cooling water to synthesis, urea and utilities units. Because of the problems in the anti-cavitation property of these pumps, their impellers were frequently broken bycavitation, thus seriously affecting the safe, stable and high-efficiency operation of the chemical equipment. The experiments were made according to the basic theories of the cavitation, and on the condition to guarantee the safety of these pumps, the relation between these factories and pump cavitation property is introduced by changing pump impeller import size, lowering the surface roughness of the pump parts, lowering the pump speed, lowering the high of the pump installation, etc, therefore the theory and experiment basis for increasing the service life of these pump impellers is provided. Although these experiments were done on these pumps of the cooling tower in the 300,000 MTPA Ammonia Plant, these experiment results can expand on other centrifugal pumps, and provide important guide for increasing the anti-cavitation property of the centrifugal pump.