Rotary connections

At designing of multiple-unit echelons rotary connections on consecutive echelons, it is necessary to have coaxially and whenever possible on small distance from each other for conservation of a whirling motion of an easy phase (Sergeys, 1972 and Tananajko, 1975). 

Blade twist extent Contact echelons Rotary connections Separation equipment The air swirler The irrigation water... 

Researches show (Kutepov, 1977 and Uollis, 1972) that velocity profiles of a gas stream for geometrically similar air swirlers automodeling to diameter the rotary connection and to a gas rate. In the installed stream gate out an axial zone of quasifirm twirl and a peripheral zone of potential twirl with the matching approached profiles (Kutepov, 1977) ... 

The analysis of known builds of rotary connections has allowed to reveal major factors (loading on a liquid phase, a monkey wall, and a stream breakaway, discharge coimection sizes), working upon aerodynamic formation of a stream. 

The analysis of known builds of rotary connections has allowed to reveal major factors (loading on a liquid phase, a monkey wall and a stream breakaway, discharge cormection sizes), working upon a water resistance of whirlwind apparatuses. Resistance is defined by the sum of pressure losses of an air swirler, in the separation chamber and on an exit from it. It is shown that pressure losses in an air swirler depend on its geometry and extent of a twisting of gas. 

Most rigs are now fitted with a system whereby the drill string is rotated by a drive mechanism in the mast rather than by the rotary table at rig floor level. Thus 90 foot sections can be drilled before connections need to be made, and the drill string can be rotated while pulling out of the hole in 90 foot sections. This improved system, which speeds up the operation and allows better reaming of the hole is known as top drive. 

Horizontal Rotating Pan Filters. These filters (Fig. 10) represent a further development of the tipping pan filter for continuous operation. They consist of a circular pan rotating around the central filter valve. The pan is divided into wedge-shaped sections covered with the filter medium. Vacuum is appHed from below. Each section is provided with a drainage pipe which connects to a rotary filter valve of the same type as in dmm filters. 

All drum filters (except the single-compartment filter) utilize a rotary-valve arrangement in the drum-axis support trunnion to facih-tate removal of filtrate and wash hquid and to allow introduction of air or gas for cake blowback if needed. The valve controls the relative duration of each cycle as well as providing dead portions of the cycle through the use of bridge blocks. A typical valve design is shown in Fig. 18-121. Internal piping manifolds connect the valve with various sections of the drum. 

If the pump is a filter pump off a high-pressure water supply, its performance will be limited by the temperature of the water because the vapour pressure of water at 10°, 15°, 20° and 25° is 9.2, 12.8, 17.5 and 23.8 mm Hg respectively. The pressure can be measured with an ordinary manometer. For vacuums in the range lO" mm Hg to 10 mm Hg, rotary mechanical pumps (oil pumps) are used and the pressure can be measured with a Vacustat McLeod type gauge. If still higher vacuums are required, for example for high vacuum sublimations, a mercury diffusion pump is suitable. Such a pump can provide a vacuum up to 10" mm Hg. For better efficiencies, the pump can be backed up by a mechanical pump. In all cases, the mercury pump is connected to the distillation apparatus through several traps to remove mercury vapours. These traps may operate by chemical action, for example the use of sodium hydroxide pellets to react with acids, or by condensation, in which case empty tubes cooled in solid carbon dioxide-ethanol or liquid nitrogen (contained in wide-mouthed Dewar flasks) are used. 

The set screw that transmits the torque from the shaft is connected to the rotary face through the spring. It also provides for the positive and correct positioning of all rotary parts. 

For most of the rotary compressors in process service, the driver is an electric motor. Compressors in portable service, however, particularly the helical-lobe compressor, use internal combustion engines. Many of the rotary compressors require the high speed that can be obtained from a direct-connected motor. The dry type helical-lobe compressor is probably the main exception as the smaller units operate above motor speed and require a speed increasing gear which may be either internal or external (see Figure 4-1). The helical-lobe compressor is the most likely candidate for a driver other than the electric motor. Aside from the portables already mentioned, engines are used extensively as drivers for rotaries located in the field in gas-gathering service. Steam turbines, while not common, probably comprise most of process service alternate drive applications. 

Another version of the dewatering screw that has been used successfully in a number of installations (Figure 40) consists of an inclined screw with a box-like back end and an internal overflow weir. The drive is usually a variable-speed motor reducer. Rotary air lock fitted with a variable-speed drive is typically used as shown in Figure 37 in connection with the plain receiving tank and an inclined screw conveyor. Materials of construction can be chrome-plated cast iron or nickel-hard casing. The rotary valve is made of hard faced tips or stainless steel replaceable blades. 

In precoating, the prime objective is to prevent the filter medium from fouling. The volume of initial precoat normally applied should be 25 to 50 times greater than that necessary to fill the filter and connecting lines. This amounts to about 5-10 lb/100 fF of filter area, which typically results in a 1/16-in. to 1/8-in. precoat layer over the outer surface of the filter medium. An exception to this rule is in the precoating of continuous rotary drum filters where a 2-in. to 4-in. cake is deposited before filtration. The recommended application method is to mix the precoat material with clear liquor (which may consist of a portion of the filtrate). This mixture should be recycled until all the precoat has been deposited onto the filter medium. The... 

Rotary kiln systems usually have a secondary combustion chamber after the kiln to ensure complete combustion of the wastes. Airtight seals close off the high end of the kiln while the lower end is connected to the secondary combustion chamber or mixing cluimber. In some cases, liquid waste is injected into the secondary combustion chamber. The kiln acts as the primary chamber to volatilize and oxidize combustibles in the wastes. Inert ash is then removed from the lower end of the kiln. The volatilized combustibles exit the kiln and enter the secondary chamber where additional oxygen is available and ignitable liquid wastes or fuel can be introduced. Complete combustion of the waste and fuel occurs in the secondar> chamber. 

The most common use of the gas turbine power system in the oil and gas industry is in combination with an electrical system (i.e., electric generators and electric motors). In 1965 such a system was used to power a rotary rig. This was a 3,000-hp rig developed by Continental-Ensco. The rig used three 1,100-hp Solar Saturn single-shaft gas turbines. These gas turbines operated at 22,300 rpm and were connected through double reduction gear transmissions to DC generators. 

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