Questions
In a delivery line for carbontetrachloride at the constant flow rate of 4 X 10^(-5) m3/s,...

In a delivery line for carbontetrachloride at the constant flow rate of 4 X 10^(-5) m3/s, the first 1000 mm long section is of 20 mm inside diameter smooth pipe followed by another 1000 mm long section of 50 mm inside diameter smooth pipe as shown in the following figure. Estimate the pressure drop over the entire length of delivery line. Neglect the minor losses due to sudden enlargement of pipe diameter.

Data: For carbon tetrachloride, Viscosity = 10^(-3) Pa.sec and density = 1500 kg/m3 For laminar flow, consider fanning friction factor, f = 16/Re
For transitional-turbulent flow, f = 0.079Re^(-0.25)

In: Mechanical Engineering

Air is compressed adiabatically in a piston–cylinder assembly from 1 bar, 300 K to 4 bar,...

Air is compressed adiabatically in a piston–cylinder assembly from 1 bar, 300 K to 4 bar, 600 K. The air can be modeled as an ideal gas and kinetic and potential energy effects are negligible. Determine the amount of entropy produced, in kJ/K per kg of air, for the compression. What is the minimum theoretical work input, in kJ per kg of air, for an adiabatic compression from the given initial state to a final pressure of 4 bar? Note that work is positive into the compressor.

In: Mechanical Engineering

A conduit carrying water vapor has one inlet and two exits. At the inlet, the velocity...

A conduit carrying water vapor has one inlet and two exits. At the inlet, the velocity 25 m/s, the pressure is 4 bar and the temperature is 350 Celsius. The area at the inlet is 0.2 m^2 . At both the exits, the temperature and pressure are 300 Celsius and 3 bar respectively. The volumetric flow rate is identical at the two exits. Assuming steady-state conditions, calculate the volumetric flow rate at the exits.

In: Mechanical Engineering

Three phase voltage is spaced? is it 120 degrees apart?

Three phase voltage is spaced? is it 120 degrees apart?

In: Mechanical Engineering

A three phase 30 hp 460 volt 60 hz, 1770 rpm design B induction motor with...

A three phase 30 hp 460 volt 60 hz, 1770 rpm design B induction motor with class F insulation and service factor of 1.0 is operating at rated shaft load in a 40 degree C environment and has an expected 20 yr life. A maintenance check shows line to line voltages to be 449.2 V, 431.3 V and 462.4 volts. The percent unbalanced voltage for this motor is:

the expected temperature rise equals?

The expected insulation life equals?

the rerating in horsepower equals?

In: Mechanical Engineering

Energy flows out of the system in form of a heat in an internally reversible process....

Energy flows out of the system in form of a heat in an internally reversible process. What happened to he entropy of the system? Explain

In: Mechanical Engineering

Energy flows out of the system in form of a heat in an internally reversible process....

Energy flows out of the system in form of a heat in an internally reversible process. What happened to he entropy of the system? Explain

In: Mechanical Engineering

Consider the design of a wastewater treatment plant (WWTP) for a community with average daily and...

Consider the design of a wastewater treatment plant (WWTP) for a community with average
daily and peak hourly wastewater design flows of 7570 m3/day and 18925 m3/day. The raw
sewage has an average of 240 mg/L BOD5 and 270 mg/L of suspended solids.

(a) Assume that the primary sedimentation process removes 55% of the suspended solids and
35% of the BOD5 of the raw sewage. Determine the SS and BOD5 concentrations in the
primary sedimentation effluent flow. (1 mark)


The primary effluent is treated by two parallel trains of the complete-mix activated sludge
process. Assume with the average flow conditions and the performance of primary
sedimentation achieved as above. Given the following parameters required for the activated
sludge process:

· Effluent BOD5 (S): 8 mg/L
· Observed biomass yield (Y): 0.55 kg biomass / kg BOD
· Endogenous decay rate (b) = 0.04 /day
· Solids retention time: 8 days
· MLVSS concentration in the aeration tank: 3000 mg/L
· Waste and recycle solids concentration: 12,000 mg/L

By using the formulas shown in appendix, determine the following:
(b) Aeration tank volume (m3).
(c) Mass flow rate of wasted sludge (kg/day). (1 mark)
(d) Volumetric flow rate of wasted sludge (m3/day). (1 mark)
(e) Return (recycle) flow rate (m3/day).
(f) Volumetric BOD loading to the aeration tank (kg BOD/m3.day). (1 mark)
(g) Food to microorganisms (F/M) ratio for the aeration tank (kg BOD day/kg MLVSS). (1 mark)
(h) Design hydraulic retention time (hr). (1 mark)

In: Mechanical Engineering

1. A plant is located at an altitude where the atmospheric pressure head is 31 ft...

1. A plant is located at an altitude where the atmospheric pressure head is 31 ft of water and the vapor pressure is 9.34 psi. The pump is placed 10 ft below the water tank with a total suction pipe length of 25 ft, pipe diameter 3 in., and friction coefficient 0.02. Assuming the given atmospheric pressure in the tank (where z1 = 10 ft and negligible velocity) and if the flowrate provided is 180 gpm, determine the available NPSH (ft). Neglect minor losses. ans 17.4 ft

In: Mechanical Engineering

Sketch constant preassure curve in T-s diagram.

Sketch constant preassure curve in T-s diagram.

In: Mechanical Engineering

A metal bar, initially at 2000K, is placed in a large tank of water at room...

A metal bar, initially at 2000K, is placed in a large tank of water at room temperature. Tank is well isolated from the environment. Between the moment bar was placed in the water and the moment when bar and water reached equilibrium, did the entropy of the metal bar increased, decreased, or remained the same? Explain.

In: Mechanical Engineering

Process X is internally reversible from state 1 to 2. Process Y is internally irreversible between...

Process X is internally reversible from state 1 to 2. Process Y is internally irreversible between same states 1 to 2. What can you say about the change in entropy of the system during process X and Y? Is one larger than the other or are they the same? Explain.

In: Mechanical Engineering

A 1-mm diameter sphere (density=7900 kg/m3) is dropped into a tank of oil (density=900 kg/m3). The...

A 1-mm diameter sphere (density=7900 kg/m3) is dropped into a tank of oil (density=900 kg/m3). The sphere develops a terminal speed of 0.25 cm/s, what is the oil's viscosity? You may assume a small Reynolds number. Show your work.

In: Mechanical Engineering

4. Explain why the energy efficiency in the case of ideal quenching is lower than energy...

4. Explain why the energy efficiency in the case of ideal quenching is lower than energy efficiency in the regime of super-ideal quenching?

In: Mechanical Engineering

The internal energy of wet steam is 2000KJ/kg. If the pressure is 1.18 MPa, what is...

The internal energy of wet steam is 2000KJ/kg. If the pressure is 1.18 MPa, what is the quality of the mixture

In: Mechanical Engineering