Chapter 9, Problem 78EP

Distilled water is being cooled by a 20% propylene glycol solution in a 1-1/U counter flow plate and frame heat exchanger. The water enters the heat exchanger at 50°F at a flow rate of 86,000 lbm/h. For safety reasons, the water outlet temperature should never be colder than 35°F. The propylene glycol solution enters the heat exchanger at 28°F with a flow rate of 73,000 lbm/h. The port distances on the heat exchanger are Lv = 35 in and Lh = 18 in. The plate width is Lw = 21.5 2 in. The plate thickness is 0.04 in with a plate pitch of 0.12 in. The chevron angle is 30° and the plate enlargement factor is 1.17. All ports have a 2 in diameter. The fouling factor of the propylene glycol solution can be estimated as 2 ×10−5 h-ft2-°F/Btu. a. Determine the maximum number of plates the heat exchanger can have while ensuring that the water outlet temperature never drops below 35°F. b. Determine the thermal and hydraulic performance of the heat exchanger with the specified number of plates.…

Liquid pentane is flowing in the shell of a shell and tube heat exchanger at a rate of 350,000lbm/hr and an average temperature of 20°F. The shell has a diameter of 27 in and a length of 16ft. The tubes in the heat exchanger are ¾-in 15 BWG tubes on a 1-in triangular pitch. The purposeof this problem is to investigate how the number of baffles impacts the heat transfer and thepressure drop on the shell side of the heat exchanger. Calculate the shell-side convective heattransfer coefficient and pressure drop for the case where the heat exchanger has 10 baffles. Repeatthe calculation for 20 baffles. Then determine thea. Ratio of the shell-side convective heat transfer coefficient for the 20-baffle heat exchangerto the 10-baffle heat exchangerb. Ratio of the shell-side pressure drop for the 20-baffle heat exchanger to the 10-baffle heatexchangerc. If the optimum baffle spacing is somewhere between 0.4Ds and 0.6Ds, how many baffleswould you recommend for this heat exchanger? What are the…

The evaporator of a vapor compression refrigeration cycle utilizing R-123 as the refrigerant isbeing used to chill water. The evaporator is a shell and tube heat exchanger with the water flowingthrough the tubes. The water enters the heat exchanger at a temperature of 54°F. The approachtemperature difference of the evaporator is 3°R. The evaporating pressure of the refrigeration cycleis 4.8 psia and the condensing pressure is 75 psia. The refrigerant is flowing through the cycle witha flow rate of 18,000 lbm/hr. The R-123 leaves the evaporator as a saturated vapor and leaves thecondenser as a saturated liquid. Determine the following:a. The outlet temperature of the chilled waterb. The volumetric flow rate of the chilled water (gpm)c. The UA product of the evaporator (Btu/h-°F)d. The heat transfer rate between the refrigerant and the water (tons)

The blade support of a hacksaw is subject to compression when a blade is installed and tightened. What is the state of stress (total combined stress) at A in MPa if the compression in the support is 1,524 N. Note: pay close attention to what is compression and what is tension and use a negative sign for the former. 100 mm 8 mm 3 mm 75 mm A 8 mm 3 mm B 50 mm

The answer is not 4.378 ft/s

The answer is not 0.293 m

please first help me solve this problem find the line of action and them help to find the forces like for example {fx=  fy= mz=  and determine the shear force in the nails

An open channel of square cross section had a flowrate of 17.2 ft³/s when first used. After extended use, the channel became 0.6-filled with silt. Determine the flowrate for this silted condition. Assume the Manning coefficient is the same for all the surfaces. Qs= ! ft³/s

(Manning equation) The triangular flume shown in the figure below is built to carry its design flowrate, Qo, at a depth of 0.991 m as is indicated. If the flume is to be able to carry up to twice its design flowrate, Q = 2Qo, determine the freeboard, I, needed. ✓ -90°- 0.991 m i m