737 AMM 飞机维护手册 AIR CONDITIONING 空调(68)

曝光台 注意防骗 网曝天猫店富美金盛家居专营店坑蒙拐骗欺诈消费者

B.  The turbine inlet overheat switch is located in the transition at the secondary heat exchanger and senses the temperature of air passing from the heat exchanger to the turbine of the air cycle machine.
C.  The compressor discharge overheat switch senses temperature of air being discharged from the compressor to the secondary heat exchanger. The switch is installed on the compressor scroll. (See view 1, figure 1.)
6.  Check Valves
A.  Two check valves are provided for each air cycle system. One valve is in the cold air supply duct from the water separator to the mixing chamber and another is in the hot air supply duct to the mixing chamber. The two check valves prevent loss of air from the distribution system should a failure occur in the air cycle system area.
7.  Water Separator
A.  Cold air leaving the air cycle machine passes through a muff to the water separator. (See figure 2.) Moisture in the air at this reduced temperature begins to condense. The condensate is so finely atomized however, that it will follow along in the air stream unless a suitable method is used to collect it. The water separator is used to collect and remove the excess moisture from the air before it enters the distribution system.
B.  The water separator is a cylindrical chamber consisting of an inlet and outlet shell assembly which houses a polyester coalescer (bag), a conical-shaped metal coalescer support, a bypass valve assembly, and a valve support guide. A coupling joins the inlet and outlet shell assemblies and secures the coalescer support. The outlet shell assembly contains a collection chamber, a baffle, and an overboard water drain. Bosses are also provided for the installation of temperature sensing probes. A bag condition indicator is also included which consists of a spring loaded piston and disk enclosed in a housing and a color coded cap.
500 
21-51-0 Page 4  BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details.  Aug 15/67 

C.  The coalescer bag and its support are conically shaped with the small diameter at the upstream end. The support fits inside the bag and has louvers shaped to impart a whirling motion to air as it passes through. Air enters the separator around the outside of the bag, passes through the bag, then through the louvers. As the damp air passes through the bag, the bag is wetted and larger droplets of water are formed. These droplets along with the air are caused to whirl by the louvers of the support. As the air and moisture pass through the separator the centrifugal force keeps the heavier moisture close to the inside of the support until it reaches the collection chamber. A cylindrical baffle approximately the diameter of the outlet duct extends inside the separator at the downstream end. The water and air whirling in a greater diameter than the baffle find it necessary to make a double reverse turn in order to leave the separator. The turning does not appreciable affect airflow but the water being much heavier cannot make the turn and remains in the collection chamber. An overboard drain mates to an outlet in the equipment bay doors. (See figure 3.)
D.  The bypass valve allows air to pass through the water separator to the distribution system without first passing through the coalescer bag. The valve opens as a result of increased pressure differential should the coalescer bag become clogged or frozen. (See figure 3.) The bypass valve opens only when the coalescer bag becomes excessively clogged to allow passage of sufficient air for proper ventilation and cabin pressure. The bypass valve assembly is secured to a mounting ring within the inlet shell assembly.
E.  If the coalescer bag is clogged, airflow through the water separator is retarded and causes an increase in pressure across the bypass valve. When the pressure differential exceeds the force of the valve loading spring, the valve opens and a portion of the air passes through the valve without first passing through the bag.
F.  The water separator also has a bag condition indicator. As the bag becomes clogged, the pressure applied to the bag condition indicator piston is increased, forcing the disk on the piston shaft toward the red colored window section of the indicator cap. When the disk is positioned within the red colored portion of the cap, it indicates a dirty bag and the bag should be replaced. (See figure 2, detail A.)
525 
Aug 15/72  BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details.  21-51-0 Page 5 

 Water Separator  502 
21-51-0  Figure 2  Feb 15/78 
Page 6 
BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details. 

525  Water Separator Airflow Schematic 
Feb 15/71  Figure 3  21-51-0 
Page 7 
BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details. 
　
中国航空网 www.aero.cn
航空翻译 www.aviation.cn
本文链接地址：737 AMM 飞机维护手册 AIR CONDITIONING 空调(68)