Pumps application ranges

Both reciprocating engines and turbines are used as prime movers in production facilities to directly drive pumps, compressors, generators, cranes, etc. Reciprocating engines for oil field applications range in horsepower from 100 to 3,500, while gas turbines range from 1,500 to in excess of 75,000. 

Figure 5-5S. Four-blade, vertical Figure 5-5T. Standard six-blade fiat blade turbine Impeller. Very vertical curved blade turbine versatile, one of the most used impeller. Gives good efficiency in wide application range. Cour- per unit of horsepower for sus-tesy of Philadelphia Gear Corp. pensions, mixing fibrous materials. Gives high pumping capacity. Courtesy of Philadelphia Gear Corp.

The simplest, and oldest, form of seal is the packed gland, or stuffing box, Figure 5.12. Its applications range from sealing the stems of the water taps in every home, to proving the seal on industrial pumps, agitator and valve shafts. 

Figure 7.14. Range of applications of various kinds of pumps, (a) Range of applications of single and double suction pumps (Allis-Chalmers Co.), (b) Recommended kinds of pumps for various kinds of head and flow rate (Fairbanks, Morse, and Co.).

Application ranges of the various kinds of devices for maintenance of subatmospheric pressures in process equipment are shown in Table 7.3. The use of mechanical pumps—compressors in reverse— for such purposes is mentioned earlier in this chapter. Pressures also can be reduced by the action of flowing fluids. For instance, water jets at 40psig will sustain pressures of 0.5-2.0psia. For intermediate pressure ranges, down to O.lTorr or so, steam jet ejectors are widely favored. They have no moving parts, are quiet, easily installed, simple, and moderately economical to operate, and readily adaptable to handling corrosive vapor mixtures. A specification form is in Appendix B. 

Because of the problems that can potentially arise with oil-sealed pumps, there is an increasing trend to use dry pumps in many applications. Various types are available including Roots pumps backed with suitable pumps (see Section 3.2.3), multi-stage Roots pumps, screw-, hook-and-claw- and scroll pumps. Dry piston pumps and diaphragm pumps are also available but their pumping speed range is restricted. The... 

---