MOMENTUM TRANSFER OPERATIONS

Dr. Vicente J. Garza

Name: ID:

ASSIGNMENT 1

Truck filling system

Theres a truck filling system as the one shown in the figure below. Gasoline flows from the storage tank into a truck for transport. The gasoline has a specific gravity of 0.7 and a viscosity of 0.52 cP. Determine the required depth h in the tank to produce a flow of 1500 liters/min into the truck. Since the pipes are short, neglect the energy losses due to friction in straight pipe segments but include everything else. Pressure at a point along a transport system Consider the transport system shown in the figure. We know that flow is from left to right. The pressure at P1 is 24 psia and the velocity is 5 ft/s. The pipe is commercial steel and has a diameter change as indicated in the figure. The liquid has a density of 60 lb/ft3 and a viscosity of 6x10-4 lb/ft-s. Determine the pressure at point P2 in psia.

5 ft

0.5 ft

liquid

Sudden

Pipe

reduction

20 ft 5 ft

2 NPS

sched 40

1 NPS

sched 40

P1 P2

Reservoir to reservoir flow

For the system shown in the figure below, calculate the vertical distance between the surfaces of the two reservoirs when water at 10C flows from A to B at the rate of 0.03 m3/s. The elbows are standard. The total length of the 3-in pipe is 100 m and the total length of the 6-in pipe is 300 m.

Power required to transport benzene Consider the transport system shown in the figure. Both tanks are open to the atmosphere. We wish to transport 2.45 lb/s of benzene from the bottom tank to the top tank. The entire pipe is comercial steel. From the bottom tank up to point a the pipe is NPS 1 1/4 schedule 40 and from point a to the top tank it is sched. 40. At point a there is a reducing 90 elbow that has a loss coefficient (K) equal to 2 based on the velocity of the pipe. Neglect pipe entrances and exits. Calculate the required WHP the pump must provide to achieve the desired transport.

Note: you can find in Blackboard in Course documents (Module 1) a table for estimating specific gravity and a nomograph to estimate viscosity of liquids.

10 ft

liquid

50 ft 20 ft

liquid

a

8 ft

Drawing

not to

scale

Coolant circulation system

The following figure shows a system used to pump coolant from a collector tank to an elevated tank, where it is cooled. The pump delivers 30 gal/min. The coolant then flows back to the machines as needed, by gravity. The coolant has a specific gravity of 0.92 and a viscosity of 2.53 cP. a. Calculate the pressure at the inlet to the pump. The filter has a resistance coefficient (K)

of 1.85 based on the velocity head in the suction line. b. Calculate the pressure drop across the filter in psi. c. Calculate the pump BHP in hp assuming the efficiency of the pump is 65%. Note: the distance from the collector tank to the filter is 10 ft (as indicated) and the distance from the filter to the pump entrance is 15 ft.