Specific duty pumps

Along with the previously described mechanical configurations, there 

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Next, let s eonsider the eiierg) eurve, the brake horsepower (BHp), ree]uired by the pump. This curve is probably the easiest to interpret because it is practically a straight line. Con.sider the following the pump consumes a certain e]uantity of energy just to maintain shut-off head. Then, as flow begins and increases, the horsepower consumption normally increases. (On certain specific duty pumps, the BHp may remain mostly flat or even fall with an increa.se in flow.) The BHp eurve is normally seen this way (Figure 7-5). 

An emergency response team, under the control of the emergency response coordinator, should be assembled with a clearly defined chain of command. The members of this team should be selected and trained for specific mitigative and communication tasks. Specific duties might include spill cleanup, first aid, employee evacuation and headcount, incipient fire response, fire pump/sprinkler control valve/fire door monitoring, firefighting, fire/emergency responder communications, and rescue. 

The base cost of a major equipment module is herein defined as the specific equipment item fabrication cost, such as that of a fractionation column, a field-erected furnace, a shell/tube heat exchanger, or process pump. Each of these items will be given a fabrication cost. A figure cost curve will be presented for each major equipment item, and will have cost of the item vs. a key process variable. These key process variables could be the furnace absorbed-heat duty, the shell/tube exchanger tube surface area, and the pump discharge pressure/gpm product number. 

High-pressure specification canned-motor centrifugal pumps can provide the solution for the hardest pumping duties. The pump illustrated in Figures 8 and 8.1 has to pump a corrosive suspension in a continuous flow at a starting temperature of 250°C and an inlet pressure of... 

The duty of a pump is its performance based on the output in foot-pounds per 1,000 lb. of dry steam, or per 100 cu. ft. of air, or per 1,000,000 B.t.u. furnished by the boilers at appropriate pressure. The duty of a steam pump can bo calculated approximately from the indicator diagram (either actual or ideal) by the formula card duty = 144,000 pv, and duty = card duty/E mEs where p = mean effective pressure of whole steam end referred to the area of any one cylinder, v = specific volume of steam at the terminal pressure in this same cylinder, Em — mechanical efficiency, and E = Steam efficiency, comprising all steam losses. 

GENERAL NOTE This table is composed of the applicable fields from Appendix Q, ANSI/API 610, Centrifugal Pumps for Petroleum, Heavy-Duty Chemical and Gas Industry Services, with the addition of data fields from the Process Industry Practices (PIP) specification that completely define necessary data for the electronic exchange of ASME B73 pump data. See Appendix Q, API 610 for complete information on the neutral data exchange file format. 

Later, I met with unit operating personnel. They were more specific. They observed that the pumparound circulating pump (see Fig. 1.1a) was defective. Whenever they raised hot oil flow to the debutanizer reboiler, the gas plant would become destabilized. Reboiler heat-duty and reflux rates would become erratic. Most noticeably, the hot-oil circulating pump s discharge pressure would fluctuate wildly. They felt that a new pump requiring less net positive suction head was needed. 

The typical duty specification required for this service is of high deUvery head and very low flow capacities. Sulfur has a melting point of 119 °C and a peculiar characteristic of a sharp rise in viscosity at a temperature above 150 C. It becomes extremely difficult to pump liquid sulfur above this temperature. The practical range for operating a sulfur pump is 125-135 °C. 

We consider the last three columns for retrofitting by heat pump systems because they have both the condensor and the reboiler with different types and duties. Table 1 shows the column, condensor and reboiler design specifications. 

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