70 - 排放
- General (Ref. Fig. Drain and Vent Schematic SHEET 1) (Ref. Fig. Drain System SHEET 1) A. Drain and Vent System The drain and vent system consists of lines collecting and carrying waste fluids and vapor overboard from the engine and nacelle accessories. Drains are provided to carry fluids from any point where lines and accessories may leak and where fluids may accumulate in a cavity. In addition, some drain lines serve as vents to carry air and vapor from the engine and accessory cavities. 2. System Description (Ref. Fig. Drain and Vent Schematic SHEET 1) (Ref. Fig. Drain System SHEET 1) The drain and vent system is divided into two parts; one which retains drained fluids until expelled during flight (reservoir), and one which discharges fluid directly overboard through the drain mast located in the fan compartment. The reservoir module is mounted on the transfer gearbox. The manifold module is also attached to the transfer gearbox and supports the drain mast, which protrudes through the fan cowl doors into the airstream. Each accessory pad seal has a separate drain cavity in the reservoir module in which leakage is contained. Manual drain valves in the bottom of these reservoirs aid in tracing the source of excess leakage. Each reservoir is identified with the accessory seal drain to which it is connected. These individual reservoirs overflow into the fuel holding tank or an hydraulic fluid/oil holding tank. This overflow is contained in the holding tank until the aircraft reaches an airspeed of 200 Knots. A pressure valve, which is part of the manifold module assembly, then admits ram air to pressurize the holding tanks and discharge any accumulated fluid overboard through the drain mast. The fluids that are discharged directly overboard are from: · the oil tank scupper · the forward sump · the fan case · the oil/fuel heat exchanger · the VBV · the VSV · the TCC · the aft sump · the fuel shroud pipe. For the shroud pipe no leakage is permissible, a separate drain line enables a clear leakage identification. · the 6 o'clock fire bulkhead. · FRV Based on two hour total flight profile (start, taxi, takeoff, cruise, descent, taxi), the individual reservoir volumes are twice the accumulated liquid level based on acceptable leakage rates. The volumes provide sufficient containment margin to discriminate between excessive and acceptable leakage rates. Fuel, Oil or hydraulic leakage limits are given in 71-00-00 P.Block 501. 3. Component Location (Ref. Fig. Drain System SHEET 1) (Ref. Fig. General Location SHEET 1) A. Drain Collector Assembly The drain collector assembly is attached to the aft side of the engine gearbox. B. Drain Module The drain module is attached directly to the aft side of the engine gearbox. It supports the drain mast. C. Drain Mast The drain mast is frangible below the cowl exterior surface to prevent damage to the engine gearbox. Should the drain mast strike the ground (or any object), the portion of the mast below the the cowling will break away. 4. Component Description A. Drain Collector Assembly (Ref. Fig. Collector Assembly SHEET 1) The drain collector assembly is composed of 4 drain collectors with manual drain valves and 2 holding tanks. The collector retains fluids until it is filled. Then the fluids overflow onto the holding tanks. B. Drain Module (Ref. Fig. Drain Mast SHEET 1) (Ref. Fig. Drain Module SHEET 1) It supports the drain mast which protrudes through the fan cowl doors into the airstream. A pressure valve which is a part of the drain module, admits ram air at 200 Knots. It pressurizes the holding tanks and enables discharge of any accumulated fluid overboard through the drain mast. 5. Material All tanks/collectors and tubing are CRES to meet fireproof requirements. Each leak isolation collector has a push-to-test poppet valve. The portion of the drain system extending outside of the cowl contour is made of frangible polyphenylene sulfide plastic. This breaking away in the event of contact with the runway. Figure 71(CFMB)-70-00-17300-06-A / SHEET 1/1 - Drain and Vent Schematic Figure 71(CFMB)-70-00-17400-06-A / SHEET 1/1 - Drain System Figure 71(CFMB)-70-00-17500-06-A / SHEET 1/1 - General Location Figure 71(CFMB)-70-00-17600-06-A / SHEET 1/1 - Collector Assembly Figure 71(CFMB)-70-00-17700-06-A / SHEET 1/1 - Drain Mast Figure 71(CFMB)-70-00-17800-06-A / SHEET 1/1 - Drain Module