Gasturbinepropelled Vessels

FUEL-OIL SERVICE PUMPS Typically, fuel oil is delivered to a propulsion gas turbine's combustion-chamber nozzles by a gear pump that is mounted on and driven by the gas turbine. In addition, a pair of two-speed electric-motor-driven rotary pumps that operate upstream of and in series with the attached pump are usually provided. Duplex strainers, filters, and heaters are also ordinarily included in a gas turbine's fuel-oil service system.

LUBRICATING-OIL PUMPS A typical gas turbine is furnished with an attached gear- or centrifugal-type lubricating-oil (LO) pump that is driven off the gas turbine. This pump takes suction from a LO reservoir and discharges synthetic oil to the bearings for the gas turbine and to control devices. Filters are also included in the LO system. In addition, electric-motor-driven gear, vane, or centrifugal pumps are ordinarily used to circulate lubricating oil through the system during start-up and cool-down periods and to serve as a backup to the attached pump. Excess oil delivered by a gas turbine's LO pump is frequently returned through a pressure regulating valve to the LO reservoir. A device is normally provided that sounds an alarm and, in some cases, automatically stops the flow of fuel to a gas turbine following a failure of the LO system.

Separate rotary scavenge pumps may be used to return oil that drains from a gas turbine's bearings to the LO reservoir. In addition, multiple-screw pumps are frequently used to circulate mineral oil through an independent lubrication system for a gas-turbine-propelled vessel's reduction gears and their bearings. Although one of these screw pumps may be driven off the reduction gears, the remaining reduction-gear LO pumps are usually electric motor driven. Some of the mineral oil in the reduction-gear LO system frequently passes through a heat exchanger in which it absorbs heat from the synthetic oil that lubricates the gas turbine's bearings. The reduction-gear lubricating oil also usually passes through a second heat exchanger in which it is cooled either by freshwater or seawater.

Survival Treasure

Survival Treasure

This is a collection of 3 guides all about survival. Within this collection you find the following titles: Outdoor Survival Skills, Survival Basics and The Wilderness Survival Guide.

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