Efficiency, hydraulic

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... 

Wherever contaminated groundwater must be recovered or prevented by migrating by hydraulic control, the expense of a valid field investigation is always recouped. Efficient hydraulic control or recovery is based on the principle of handling (and treating) the smallest volume of water containing the highest concentration of dissolved chemicals as possible. 

Although atrazine has a soil half-life of 30-90 days, transport out of this zone into receiving waters leads to longer half-lives [101]. For pesticides with high water solubilities, such as atrazine, tributary inputs can be a major source, and environmental response to sources is controlled by long hydraulic residence times and slow transformation rates. Despite the fact that only 1% of the applied atrazine is lost by transport to rivers and lakes, and another 1% by aerial transport, the large quantities applied, together with efficient hydraulic transport result in accumulation in aquatic systems. 

D-O SiphonSizer The D-O SiphonSizer (Fig. 19-25) is a high-efficiency hydraulic classifier developed originally for the washing and sizing of phosphate rock. In ore-dressing work it is normally a two-product unit but by use of an upper column sealed at the top and... 

Type Material Efficiency (%) Hydraulic horsepower (theoretical work)... 

Mechanical Pressing. Historically, the first large commercial production of oils from seeds and nuts was carried out using labor-intensive hydraulic presses. These were gradually replaced by more efficient mechanical and screw presses. Solvent extraction was developed for extraction of seeds having low oil content. For seeds and nuts having higher oil content, a combination of a screw press followed by solvent extraction is a common commercial practice (prepress—solvent extraction). 

Typically, the power iaput ranges from W/kg (0.25—0.75 horsepower units/gal) of processed mass. Hydraulic drives, mechanical, and electronic controls are also used to achieve variation in speed of the blades for efficient processing. 

Likewise for polytropic efficiency which is often considered as the small stage efficiency or the hydraulic efficiency ... 

The slide is located in the compressor casting below the rotors, allowing internal gas recirculation without compression. Slide valve is operated by a piston located in a hydraulic cylinder and actuated by high-pressure oil from both sides. When the compressor is started, the slide valve is fuUy open and the compressor is unloaded. To increase capacity, a solenoid valve on the hydraulic hne opens, moving the piston in the direction of increasing capacity. In order to increase partload efficiency, the slide valve is designed to consist of two parts, one traditional shde valve for capacity regulation and other for built-in volume adjustment. 

Gives very clean sands and has relatively low hydraulic water requirements (0.5 t/t underflow). One of the most efficient single-stage classifiers available for closed circuit grinding and washing. Relatively expensive. 

Efficient separations, but requires 3 t hydraulic water/t solids feed. Used to produce exceptionally clean underflow fractioned into... 

Another auxiliaiy unloading system that has proven to be very effective and efficient involves the use of moveable, hydraulically operated truck dumps located at the disposal site. Operationally, the trailer is backed up onto one of the tipping ramps, with or without its tractor. The back of the trailer is opened, and the unit is then tilted upward until the wastes fall out by gravity. The time required for the entire unloading operation typically is about 5 min per trip. 

Since the exacd value of the hydraulic efficiency e, is never known, V/ can be taken as an approximation where e is the gross (hydraulic horsepower/brake horsepower) pump efficiency. Efficiencies of pump designs running as turbines are usually 5 to 10 efficiency points lower than those as pumps at the best efficiency point. 

These motors have a lower efficiency as a result of running in liquid, causing more liquid drag and also axial thrust bearing loss, which is also a part of the motor. However, this lower efficiency of the motor is compensated by fewer mechanical and hydraulic losses in a submersible motor-pump installation, compared to a vertical turbine pump installation. 

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