TM 5-6115-434-12
e.
Water System (fig. 1-12 and 1-13). The water system, when provided with an external supply of water will
deliver hot and cold water under pressure to other elements of the MUST hospital. The water system includes a cold
water pump, hot water pump, exhaust-gas-to-water heat exchanger, exhaust gas flow control valve, hot water storage
tank, pressure (surge) tank, pressure relief valves, check valves, pressure and temperature control switches, and
interconnecting lines and fittings. The cold water pump receives inlet water and delivers the water to the cold water
outlet and to the hot water heat exchanger. A surge tank is connected to the cold water system to prevent .the noise and
effects of water hammer and cycling. The water is heated in the heat exchanger and goes to the hot water storage tank.
The hot water pump draws water from the storage tank and delivers it under pressure to the hot water outlet. Pressure
switches are utilized to activate the hot and cold water pumps as required to maintain a constant water pressure in the
system. A hot water temperature switch controls the positioning of the exhaust gas flow control valve to regulate the flow
of exhaust gas to the heat exchanger and maintain a constant water temperature. Temperature and pressure relief
valves in the water system protect ,the system from damage due to excessive temperature and/or pressure. A
thermostatic switch in the water tank compartment is used to control a solenoid valve to bleed hot compressed air from
the engine compressor into the water tank compartment to prevent freezing during low temperature periods of operation.
Drain fittings are provided to completely drain the water system during periods of inoperation.
f.
Compressed Air System (fig. 1-11 and 1-14). The compressed air system consists of various ducts, valves,
and controls utilized to deliver compressed air from the gas turbine engine compressor to the heated air system, water
tank compartment, engine air cleaner ejector, vacuum system eductor, and for external pneumatic power requirements.
Compressed air to the heated air system is bled off through the engine load control valve which is modulated by a load
control thermostat in the engine exhaust to prevent the engine from being overloaded by excessive shaft and pneumatic
loads. Compressed air to the engine air cleaner ejector flows continually to scavenge dust and foreign material
separated from the intake air by the engine air cleaner during engine operation. Compressed air to heat the water tank
compartment is controlled by a thermostatic switch in the water tank compartment and a solenoid valve in the
compressed air line. Compressed air to the vacuum system eductor and to the external pneumatic fitting is controlled by
manually operated valves.
g.
Vacuum System (fig. 1-11 and 1-15). The vacuum system provides suction for use in other elements of the
MUST hospital. The suction or partial vacuum is created by flowing compressed air through an eductor which creates a
partial vacuum when air is passed through a venturi shaped section. The compressed air is exhausted from the eductor
through a sound attenuated exhaust duct at the top of the power unit enclosure. The vacuum system is controlled by a
manually operated valve in the compressed air line to the eductor. The vacuum system consists of an eductor, manual
control valve, a sound attenuated exhaust duct, and interconnecting ducts and fittings.
h.
Enclosure (fig. 1-1 and 1-2). The enclosure provides support and protection for the various systems and
components of the power unit. The enclosure consists of a welded aluminum alloy frame with access doors and
removable panels to provide access to controls and instrument panels and to all internal components. Internal bulkheads
and separating panels provide compartmentalization of the enclosure interior to separate the various systems and
components and to provide storage for accessory components. The enclosure access doors, panels, bulkheads, and
separating panels are lined with insulating and sound attenuation materials. Suitable openings, doors, and panels are
provided in the enclosure to facilitate air intake, exhaust, and service connections to the power unit. The air intake for
the gas turbine engine utilizes a vortex type air cleaner that is scavenged by compressed air with scavenged material
and air exhausted
1-18
