Shafts, centrifugal-pump

NonmetalHc centrifugal pumps utilize polymers for all components coming into contact with the pumping media. Even the steel (qv) shaft is sleeved with plastic to isolate the shaft from the fluid. Mechanical seals are reversed so that the metal face does not come into contact with the corrosive... 

In a vibration analysis, hydraulic instability is displayed at the vane-pass frequency of the pump s impeller. Vane-pass frequency is equal to the number of vanes in the impeller multiplied by the actual running speed of the shaft. Therefore, a narrowband window should be established to monitor the vane-pass frequency of all centrifugal pumps. 

Shaft seal requirements and two common types of seals, packed stuffing boxes and simple mechanical seals, are described and discussed in this section. A packed box typically is used on slow- to moderate-speed machinery where a slight amount of leakage is permissible. A mechanical seal is used on centrifugal pumps or other type of fluid handling equipment where shaft sealing is critical. 

Action of a Centrifugal Pump Briefly, the action of a centrifugal pump may be shown by Fig. 10-37. Power from an outside source is applied to shaft A, rotating the impeller B within the stationary casing C. The blades of the impeller in revolving produce a reduction in... 

The shaft-seal development for high-pressure centrifugal pumps is quite similar to that explained for compressors. The traditional mechanical seals lubricated by liquids are now being partly replaced, for obvious reasons, by gas-lubricated ones. 

Step 6. Multiply the horsepower per pound of steam value calculated in step 5 by the turbine steam flow, in pounds per hour. This is the total shaft work that appears at the turbine s coupling. This is the amount of horsepower that is available to spin a centrifugal pump. 

For mechanical heat equivalent, the following are recommended (a) For pumps, use 50 percent of the connected motor horsepower for centrifugal pumps that are deadheaded, unless better information is available, (b) For agitators, use 100 percent of the vendor rated shaft input horsepower for the input shaft (total power less drive and bearing inefficiencies) for the actual material in the vessel. 

What is the upper limit of specific speed and capacity of a 1750-r/min single-stage double-suction centrifugal pump having a shaft that passes through the impeller eye if it handles clear water at 85°F (302 K) at sea level at a total head of 280 ft with a 10-ft suction lift What is the efficiency of the pump and its approximate impeller shape ... 

According to Table 5.13, the centrifugal pump efficiency depends on the volumetric flow rate. From Table 5.13, the pump efficiency is 45 %, Therefore, from Equation 5.49 the pump shaft power. 

The pumping system (Figure 3) has been modified from the one described by Setser et al. (13) to avoid contact between the sample stream and metallic surfaces. The 12-stage centrifugal pump is now used to power the hydraulically driven clean-pump. Seawater from the centrifugal pump is exhausted in situ after driving a reciprocating piston in the sample pump. This drive piston shares a common shaft with two acetal resin (Delrin) pis-... 

A centrifugal pump installed in a pipeline as conveying device is an excellent mixing device [39]. One or more stirrers can also be incorporated on the same shaft in a short pipe section ("in line blending ) [191, 587]. 

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