Turbine drive, pumps

The primaiy advantages of a centrifugal pump are simplicity, low first cost, uniform (nonpulsating) flow, smaU floor space, low maintenance expense, quiet operation, and adaptability for use with a motor or a turbine drive. 

Steam turbines are divided into two broad categories those used for generating electric power and general-purpose units used for driving pumps, compressors, etc., and frequently called mechanical-drive turbines. 

Mechanical Drives. Mechanical drive gas turbines are widely used to drive pumps and compressors. Their application is widely used by offshore and petrochemical industrial complexes. These turbines must be operated at various speeds and thus usually have a gasifier section and a power section. These units in most cases are aero-derivative turbines, turbines, which were originally designed for aircraft application. There are some smaller frame type units, which have been converted to mechanical drive units with a gasifier and power turbine. 

The system should have an aeeumulator to maintain suffieient oil pressure while the standby pump aeeelerates from an idle eondition. An aeeumulator beeomes a must if a steam turbine drives the standby pump. Overhead tanks are speeified by many users to assure flow to eritieal maehinery eomponents. The sizing of the tanks varies depending on the applieation. In some gas turbine applieations, the bearings reaeh maximum temperature as long as 20 minutes after shutdown. 

If HjS is continuously present in the flare gas or if the flare seal drum also functions as a sour water disengaging drum, then the effluent seal water must be routed to a sour water stripper, desalter, or other safe means of disposal. Withdrawal from the drum is by pump in place of the normal loop seal arrangement. Two pumps are provided one motor driven for normal use, and the other having a steam turbine drive with low pressure cut-in. The seal drum level is controlled by LIC with high and low alarm lights plus an independent high level alarm. 

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. 

Gas and steam turbines rigid turbo-generator rotors rotors turbo-compressors machine-tool drives small electrical armatures turbine-driven pumps. 

If a steam turbine generates electricity, then the flow through the turbine can be varied within the minimum and maximum flows allowed by the machine. If a steam turbine is connected directly to a drive (e.g. a back-pressure turbine driving a large pump), then there is likely to be no flexibility to change the flowrate through the steam turbine as this is fixed by the power requirements of the process machine. 

A031 Pump Item Number Turbine Drive ITEM NO T c 24... 

Process applications of combustion gas turbines are chiefly to driving pumps and compressors, particularly on gas and oil... 

Economic Optimum Pipe Size for Pumping Hot Oil with a Motor or Turbine Drive... 

Flow control via pump speed adjustment is less common than the use of throttling with valves, because most AC electric motors are constant-speed devices. If a turbine drive is used, speed control is even more convenient. However the advent of the pulse-width modulated (PWM) adjustable speed drive with sensorless flux-vector control has brought adjustable speed (AS) pumping into the mainstream of everyday applications. 

Rotational speeds vary from approximately 1,800 to 14,000 rpm and can be modulated over a wide range. Such variable speed is an advantage if the turbine is used to drive pumps and compressors or if it is to convert a variable steam flow into electricity, as is the case with thermal solar systems. When provided with the appropriate speed governor, steam turbines can provide excellent speed stability, which is desirable when the turbine serves as the prime mover in electric generators. 

Answer by Author The hydraulic-motor drive was an arbitrary selection. It was a ready means for providing the variable speeds necessary for a wealth of pump calibration data. Electric-motor and turbine drives could have been utilized. 

Secondary circuit water boiling up and abrupt increase of heat removal from the primary coolant occurs to result probably in its freezing. Steam turbine drive of feed water pump and by-pass pipelines connecting steam generator inlet and steam header through orifices are provided in the secondary circuit to decrease consequences of such accidents. 

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