Chemical Engineering Answers

In a typical fruit drying process, fresh apricots without seeds (contains 82% of humidity) are dried in a dryer. After drying process, dry apricots contain 22% humidity. What is the mass loss of apricots during drying process. In order to obtain 1 kg dry apricots, how many kg of fresh apricots arerequired.

90kg alcohol-water mixture containing 25% alcohol is fed to a distillation column. Top and bottom product contains 85% and 3.2% alcohol, respectively. What percentage of alcohol in feed is recovered in top stream?

A hot fluid at 200 °c enters a heat exchanger at a mass flow rate of 10000kg/hr. It's specific heat is 2000j/kg°c. It is to be cooled by another fluid enters at 25°c with a mass flow rate 2500kg/hr and specific heat is 400 j/kg°c. The overall heat transfer coefficient based on outside area of 25m^2 is 250W/m^2°c. Find the exit temperature of the hot fluid when the fluid are in parallel flow and counter flow

A solution of washed raw cane sugar is coloured by the presence of impurities. It is to be decolourised by the treatment with an adsorptive carbon in a contact filtration plant. The data for an equilibrium isotherm is given below. The original solution has a colour concentration of 9.6 measured on an arbitrary scale and it is desired to reduce colour to 10% of its original value

Kg carbon/kg solution:

0.001

0.004

0.008

0.02

0.04

Colour units /kg solution

9.6

8.6

6.3

4.3

1.7

0.7

Convert the data to a suitable form for plotting the equilibrium isotherm and determine the quantity of fresh carbon required per 1000 kg of solution for a two stage counter-current operation?

Explain briefly with step by step process?

The inreversible isomerization

A->B was carried out in a batch reactor and the following concentration-time data were obtained: T(min) 0 3 5 8 10 12 15 17.5

CA(mol/dm3) 4.0 2.89 2.25 1.45 1.0 0.65 0.25 0.07

(a) Use regression to determine the reaction order, a, and the specific reaction rate, ka.

The flat base of the bottom of an electric water heater is made of a 2 mm thick steel plate. thermal conductivity of 40 W/(m. oC), and an insulating plate with a thickness of 4 mm and thermal conductivity of 0.06 W/(m.oC). Between the steel and insulating plates there is an electrical resistance (RE) that dissipates a power of 800 W. 

Consider the steady state situation with boiling water at a temperature of 100 oC and with a coefficient of heat transfer by convection of 3000 W/(m2. oC), while the ambient air, which is in contact with the insulator, it remains at a temperature of 25oC and a convection heat transfer coefficient of 10 W/(m2.oC).

Considering a perfect thermal contact between the electrical resistance and the steel and insulating sheets and that the base of the heater has an area of 0.018 m2, determine: 

a) The temperature (TR) of the electrical resistance

b) The rate of heat lost to the air through of the insulating plate

ç). The rate of heat lost to water through the steel plate

d²C/ dy²= [dC²/dȳ². (1/√(y)) + dC/dȳ .d/dȳ (1/√(y))]

please try to bring the equation a modified Bessel Equation of appropriate order. Identify the the order and write down the analytical solution for the concentration distribution C= f (ȳ) and thus C= f(z) using modified Bessel Functions.

The values are given if you need it.

reaction rate constant (k) =0.05 cm/s

Diffusion coefficient of ‘A’ (D) = 0.01 cm2/s

The cavity opening at the top (a)= 0.1 cm

Concentration of ‘A’ at z=0 (C₀)= 1 mol/cm3

Length (L)= 1 cm

Demonstrate( diagram and brief explanation ) Boolean algebra in a PLC context: use 2X1C’s and label them A,B. Show how you would achieve both or and in ladder logic

Demonstrate( diagram and brief explanation) how logic function MOV and ADD are represented in. PLC ladder logic context

An oil storage tank has 20mm steel walls covered with 50mm of fiber glass insulation. if the oil temperature is kept at 150 degree Celsius, what is the rate of heat loss when the outside temperature is 20 degree Celsius and external air coefficient is 20W/m². How much would the heat loss be reduced by doubling the thickness of the insulation?