Hydraulic turbines

Tests conducted to operate centrifugal pumps as hydrauhc turbines throughout the head-capacity-speed range show that a good centrifugal pump generally makes an efficient hydraulic turbine. From theoretical considerations it is possible to state that at the same speed... 

Steam, gas and hydraulic turbines, and turbine generator set units... 

A - ABSORBER FD - FLASH DRUMS C - COMPRESSORS 1C - INTERCOOLED COMPRESSORS P- PUMP T - HYDRAULIC TURBINE D - DEHYDRATOR AC - AFTER COOLERS X- THROTTLE G GENERATOR... 

Reflux overhead vapor recompression, staged crude pre-heat, mechanical vacuum pumps Fluid coking to gasification, turbine power recovery train at the FCC, hydraulic turbine power recovery, membrane hydrogen purification, unit to hydrocracker recycle loop Improved catalysts (reforming), and hydraulic turbine power recovery Process management and integration... 

American engineer James B. Francis invents the hydraulic turbine. 

American engineer Lester A. Pelton develops the hydraulic turbine. 

Buse, F. (1981) Chem. Eng., NY 88 (Jan 26th) 113. Using centrifugal pumps as hydraulic turbines. 

Chada, N. (1984) Chem. Eng., NY 91 (July 23rd) 57. Use of hydraulic turbines to recover energy. 

The amount of energy that may be recovered from liquid streams by using a hydraulic turbine is given in Figure 8-1. Similarly, Figure 8-2 gives the results when expansion turbines are used to recover energy from gas streams. 

The hydraulic turbines at Boulder Dam power plant are rated at 86,000 kW when water is supplied at a rate of 66.3 m3/s. The water enters at a head of 145 m at 20°C and leaves through a 6 m diameter duct. 

Wood. Although lignum vitae and oil-impregnated maple and oak are useful up to 70°C, they have largely been replaced as bearing materials by porous metals, plastics, and mbber. Typical application of wood bearings are with water and other low viscosity fluids at relatively low speeds in pumps, conveyors, hydraulic turbines, food and chemical processing, and ship propeller shafts (27). 

Glycerine is metered by means of a bucket conveyer (Fig. 45b) driven by hydraulic turbine. 

Reynolds numbers are of value in the various fields because lesis of models are directly comparable to full-scale results of geometrically similar shapes if the Reynolds ratio for the model equals that of the actual or full-scale project. This has its practical applications in the field of hydrodynamics, in the study of water resistance of hulls or floats, and in the study of water velocities, levee problems, etc., of large rivers. It is used also to establish the best proportions of hydraulic turbines through the use of models. Much of the science of aeronautics rests upon experimental data obtained in wind tunnels. Dangerous inaccuracies might exist in drawing conclusions for actual construction from model tests, unless either the model were, tested at a Reynolds number equal to that of the completed project, or due corrections and allowances were made for the Reynolds number. See also Heat Transfer. 

Glycerin is metered by means of a bucket conveyor (Fig lb) driven by hydraulic turbine The arrangements for introducing measured quantities of acid and glycerin are connected by a lever (2) in such a way that the influx of acid and NG into the nitrator proceeds at a predetermined ratio. Movement of the tipping vessel exerts a pull on the lever, and this takes the brakes off the bucket conveyor. The conveyor immediately starts to move, and continues to do so until the acid metering vessel returns the lever to its former position and stops the conveyor again... 

A hydraulic turbine can be incorporated on the same shaft as a steam turbine (or motor drive). This arrangement can be used to provide about... 

A few other examples in which models may be used include ships in towing tanks airplanes in wind tunnels hydraulic turbines, centrifugal pumps, dam spillways, and river channels and the study of such phenomena as the action of waves and tides on beaches, soil erosion, and the transportation of sediment. It must be emphasized that the model may not necessarily be different in size from its prototype. In fact, it may be the same device, the variables in the case being the velocity and the physical properties of the fluid. 

Hydraulic turbines are used for recovering energy from high-pressure liquid streams. A common process application is an absorber-stripper combination. In this apphcation, a gas is absorbed in a solvent at a high pressure, where absorption is favored. Then, the solvent is stripped of the absorbed components at a low pressure, where stripping is favored, to recover the solvent. Thus, the energy of the high-pressure solvent stream from an absorber can be partially recovered by a hydraulic turbine. There are three types of hydraulic turbines, the Pelton-wheel turbine, the Francis turbine, and the propeller reaction turbine, an axial type turbine. The propeller reaction turbine is used in hydroelectric applications and will not be considered further. The Pelton-wheel and Francis tur-... 

Figure 5.23 Hydraulic turbines. From Ref. 40 with permission.

The turboexpander is also a hydraulic turbine used for flashing liquids and liquids releasing dissolved gases as discussed by Swearingen [42]. Capacities range from 50 to 1,000 hp (39.3 to 746 kW), suction pressures from 1,000 to 1,500 psia (69 to 103 bar) and discharge pressures from 50 to 200 psia (3.45 to 13.79 bar). In an illustrative example, Swearingen cites an isentropic efficiency... 

An important issue is the proper design of the distributors for the solvent and an adequate liquid holdup in the pump sump to balance fluctuation in the liquid flow sometimes caused by foaming. Foaming may require addition of suitable antifoaming agents. To reduce the mechanical energy demand the laden solution is depressurized over a hydraulic turbine mounted on the pump shaft. In processes which need addition of inhibitors to prevent corrosion, careful control of inhibitor concentration is required. 

---