Question

40. Pneumatic Freight Pipeline (5 engineers) A freight pipeline involves the use of a fluid moving through a pipeline to transport a solid or a liquid substance over a certain distance; in other words, the moving fluid conveys "freight." The fluid itself in many cases is merely discharged at the destination Consider the freight pipeline sketched in Figure 11.8. At the inlet, air is moved into the pipeline by a blower. Just downstream is a hopper from which the substance to be conveved is fed into the moving air stream. The mixture then flows through the pipeline until it encounters a separator. The air is discharged to the atmosphere, and the freight is collected at the bottom of the separator, where it can be discharged to a receiver tank. The system of Figure 11.8 is to convey green peas to a packaging machine. Once packaged, the peas will be frozen and sent to market. The peas are to be conveyed at a rate of 3 000 kg/hr, which is the maximum capacity of the packaging machine. The path to be followed is as indicated in the figure. 6 mixture 10 ow direction 1. blower 6. 25 m 8. 15 m 10. separator 2. feed hopper 3. 20 m air inlet 5. 10 m FIGURE 11.8. A freight pipeline using air to convey peas To be designed, selected, or determined: The properties (particle density and average particle size) of peas The material the pipeline should be made of. The air flow rate required to convey the peas at maximum capacity. 1. 2. 3. 4. The total pressure drop of the system. 5. The power requirements of the blower, and the blower type (positive displacement, or rotary, or centrifugal, etc.). 6. The feed hopper and the separator 7. The configuration of the elbows; i.e., the radius of each elbow. If the elbows have too sharp a radius, then a relatively high pressure drop will be encountered

Answer 1

INPUT OUTPUT A A0 B1 SUMI SUMO Cout

a) Decoder and external gates: Here, the select min terms from decoder for each output (i.e. SUMO, SUM1 and Cout) and logically OR them as shown below um0 Decd sum1 BOxt 2k+1 cout B1 x1 2k+1 A0 x1 A1 x1 b) ROM:

16B. ROM cout 00100 "00 00 00 +00 00 00 00 08 00 00 00 00D Oc 00.00.00.00 sumo -、sumi c) 16x1 multiplexers:

Cout sum1