ENVIRONMENTAL ENGINEERING - QUESTION 22.3 : A well delivers 225 US-gallons per minute of water to a chemical plant during normal system operation. (a) Calculate its flowrate in the unit of mega US-gallon per day or MGD. (b) The following formula is written next to the chlorine feed point : (chlorine feed rate, lb / day) = (flowrate, MGD) X (dose, mg / L) x (8.34). If this formula is correct, then what should the chlorine feed rate to be in pounds per day (lb / day) if the desired dose is 2 mg / L. (c) Prove by calculations that the constant 8.34 in the formula next to the chlorine feed point is correct. Let 1 US-gallon = 3.78541 L and 1 mg = 0.0000022046 pound.

1 Answers  

---

Explain why is a vacuum breaker used on shell and tube heat exchangers that are utilizing steam as the heating utility?

0 Answers  

---

For what ration of Lengh/Dia. of tank (Jacketed tank), maximum heat transfer area is available?

0 Answers  

---

In Galvonised iron and stainsteel pipes, in which pipe friction losses will more and why ?

0 Answers  

---

Question 54 - There are 2 alternatives of investment. Choice 1 : A trader offers you an investment opportunity where your investment of A$15000 presently will be A$18000 after 4 years. Choice 2 : A bank offers you 5 % annual return for your initial investment of A$15000. Question a : What is the equivalent bank payment after 4 years? Question b : By using the concept of equivalence in engineering economy, which is the better choice, betwen 1 and 2, that will be more profitable after 4 years?

1 Answers  

---

According to Shockley equation, the I – V characteristic of a diode is approximated by I = IS [ exp (nVD / VT) – 1 ]. For silicon, let the reverse bias saturation current IS as 0.000000000001. If n is ideality factor with value of 1.5, VT as thermal voltage drop of 0.026 V at room temperature, what is the value of current I that passes through the silicon diode in the heater of evaporator when the forward voltage drop VD = 0.026 V? Please take note that exp is the exponential function with e(1) = 2.718, e(2) = 7.389.

1 Answers  

---

How to caliculate the boil up rate, dia and height in both packed and tray distillation columns and any referance books for the design.

0 Answers  

---

How much experience you are having in commercial software for protein design?

0 Answers   Aliens Group,

---

What is the method adopted to minimize shell side pressure drop in a shell?

0 Answers  

---

For a Vernier scale of representative fraction (RF) = 1 / 25, calculate the length of the scale for the reading up to 4 metres.

1 Answers  

---

How to determine the particle size distribution for a given bulk solid?

3 Answers  

---

Question 41 - According to Raoult's law, the pressure when vapor is completely condensed, P = x(1) P(1) + x(2) P(2) ... + x(n) P(n) when x(1), x(2) ... x(n) are the mole fractions of component 1, 2 ... n and P(1), P(2) ... P(n) are the vapor pressures of component 1, 2 ... n. A vapor at 74 degree Celsius containing 70 mole % water and 30 mole % ethanol is to be completely condensed. At the temperature of 74 degree Celsius vapor pressure is 0.38 atm for water and 0.97 atm for ethanol. What is the minimum pressure the compressor must be operated?

1 Answers  

---