Answer / chem

Pinch-technology is a method for analyzing and designing
the use of heat energy. It can be best applied to process
industry which uses large amounts of heat energy. Pinch-
technology is based on mass and heat balance of the
concerned process. All the process streams are analyzed.
The so-called hot composite curve consists of all the
streams, which require cooling and the cold composite curve
consists of all the streams, which require heating. With
help of these curves, all the heat transfer of the process
can be analyzed simultaneously. Optimal targets for energy
consumption can be obtained before the design of the heat-
exchanger network. These targets are based on economical
optimization. Pinch-technology can be used also when
designing heat and power cogeneration and for optimal
placing of heat pumps. Computer programs and graphs are
used when designing processes with the pinch-technology.
The composite curves and energy consumption targets can be
easily composed when using software based on pinch-
technology. The topology of the heat-exchanger network in
the early phases of design is convenient to present with
graphical grid presentation

Answer / prabhakaran

to represent a new set of thermodynamically based methods
that guarantee minimum energy levels in design of heat
exchanger networks

Answer / sheela

Pinch Technology is used for energy integration.Most of the
UK consultancy companies offer consultancy on this.
Basically it can be used everywhere and anywhere
when there is a process that uses energy. It is simple but
very efficient. Plenty of companies uses pinch without
knowing that they use pinch at preliminary level But a
detailed pinch design will really save lots of money
interms of energy.
Many people gets confused about PINCH. It doesnt need any
complex calculations. But you have to follow the procedure
and some simple logics thats it. Q=UAdeltaT,. CPdeltaT.
There is no major formulas and difficult equations involved
in it. Pinch Analysis and process integration is the best
book.

Answer / amir

optimum utilization of heat transfer between hot and cold
streams

Answer / prachi

energy intergration via systematic heat exchanger
networking...

Answer / afrin

it is a methodology for minimizing energy consumption of a chemical process in a thermodynamically feasible manner i.e by optimising heat recovery system...............

UNIT OPERATION - EXAMPLE 9.2 : A distillation column separates 10000 kg / hr of a mixture containing equal mass of benzene and toluene. The product D recovered from the condenser at the top of the column contains 95 % benzene, and the bottom W from the column contains 96 % toluene. The vapor V entering the condenser from the top of the column is 8000 kg / hr. A portion of the product from the condenser is returned to the column as reflux R, and the rest is withdrawn as the final product D. Assume that V, R, and D are identical in composition since V is condensed completely. Find the ratio of the amount refluxed R to the product withdrawn D. Hint : Solve the simultaneous equations as follow in order to find the answer (R / D) : 10000 = D + W; 10000 (0.5) = D (0.95) + W (0.04); 8000 = R + D.

1 Answers  

Question 46 - In a steady state one dimensional conduction with no heat generation, the differential equation is d / dx (k dT / dx) = 0. Prove that T(x) = ax + b, where k, a and b are constants. (b) At x = 0, T = c and at x = L, T = d. Prove that T(x) = (d - c) x / L + c for boundary conditions.

1 Answers  

DIFFERENTIAL EQUATIONS - EXAMPLE 20.2 : During the landing process of an airplane, the velocity is constant at v. (a) If the displacement of the plane is x at time t, find the differential equation that relates t, x and v. (b) The plane has 2 parts of wheels - the front and the back, separated by a distance L. The front part of the wheel touches the land first, that allows the straight body of the plane to form an angle T with the horizontal land. If the vertical distance between the back part of the wheel and the horizontal land is y, find the equation of y as a function of L and T. (c) Find the differential equation that relates dy as a function of dt, v and sin T. (d) Find the differential equation that consist of dy as a function of y, L, v and dt. (e) Find the equation of y as a function of v, L, t and C where C is a constant. (f) When t = 0, prove that y = exp C as the initial value of y.

1 Answers  

Question 106 - In a wavefunction, let P(x) = A cos kx + B sin kx. By using the boundary conditions of x = 0 and x = l, where P(0) = P(l) = 0, prove by mathematical calculation that P(x) = B sin (npx / l) where p = 22 / 7 approximately, n is a rounded number. A, B and k are constants.

1 Answers  

what is water at its saturation temperature ??????????

2 Answers   Essar,

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0 Answers   HPCL,

how to reduce COD from plant waste water closed circulation system

1 Answers  

At what temperature does water have maximum density?

0 Answers  

BIOPROCESS ENGINEERING - EXAMPLE 14.2 : An aqueous solution with 2.5 g of a protein dissolved in 600 cubic centimeters of a solution at 20 degree Celsius was placed in a container that has a water-permeable membrane. Water permeated through the membrane until the h - level of the solution was 0.9 cm above the pure water. (a) Calculate the absolute temperature of the solution, T in Kelvin, where T (Kelvin) = T (degree Celsius) + 273.15. (b) Calculate the osmotic pressure, P of the solution by using the formula P = hrg where h is level of the solution, r is density of water with 1000 kg per cubic meter, g = 9.81 N / kg as gravitational acceleration. (c) Calculate the concentration of the protein solution, C in kg / cubic meter. (d) Calculate the molecular weight of the protein, (MW) = CRT / P where R = 8.314 Pa cubic meter / (mol K) as ideal gas constant.

1 Answers  

ACCOUNTING AND FINANCIAL ENGINEERING - EXAMPLE 34.16 : An engineer would like to invest his money in a home, business and bond. The implicit interest payment frequency is monthly for home loans, quarterly for business loans; semi annually for bonds. A generalized mathematical formula to calculate I = interest rate equivalence is I = (1 + i / N) ^ N - 1 where i = annual interest rate, N = number of payment per year. (a) Calculate the value of N for : (i) home loans; (ii) business loans; (iii) bonds. (b) For i = 0.08, find the value of I for : (i) home loans; (ii) business loans; (iii) bonds.

1 Answers  

Can condensate control in a reboiler cause water hammer problems?

0 Answers  

Three solid objects of the same material and of equal mass – a sphere, a cylinder (length = diameter) and a cube – are at 5000C initially. These are dropped in a quenching bath containing a large volume of cooling oil each attaining the bath temperature eventually. The time required for 90% change of temperature is smallest for a) cube b) cylinder c) sphere d) equal for all the three whyyyyyyy???????

3 Answers   GATE,