Dear Members,
In Centrifugal Compressors we calculate Polytropic efficiency only -Why not adiabatic efficiency ?
Where we calculate and use adiabatic efficiency?
Thanks in advance.
Dear members,
Though add no of tube passes are not unknown, most STHE have an even number so that both tube-side inlet and outlet piping connections are made at the same end.What are the advantage?
Thanks in advance.
Dear members,
In March 1981 issue of HYDROCARBON PROCESSING page 135, an example is given for partial condensers. Some-one could clarify what is the dry gas flow and dry gas molecular weight. The gas stream is being natural gas how molecular weight could be 36.7 against natural gas molecular...
Dear members,
As in page no- 62 of Applied process design for chemical and petrochemical plants by E.E. Ludwig volume three, how to incorporate tube material thickness and conductivity in the worked out example in page no-106(Condensation in the presence of non condensables).Any suitable...
Dear members,
In relief valve calculations,to avoid chattering because of flow capacity is small, two valves are choosen when calculated orifice area is high, with approximately 1/3 and 2/3 area. The smaller valve can be set to relieve at 3% higher pressure than the larger one. Why is it so...
Dear friends,
I use the following equation to calculate water VP.
Error is very insignificant as shown below:
VP.Calctd VP from
Temp°F Psia Steam Table %Error
212 14.701 14.696 0.040
259.28 35.650 35.0 0.145
292.71...
Dear members.
I use the following equations to calculate inlet and outlet nozzles' dia :
S(V)2 = 3000 max.
Where S - Density kg/m3; V - in M/S
And the following equations to calculate the pressure drop in the nozzle.
Inlet nozzle = rho R(V)^2/9266
Outlet nozzle = 1.25 rho R(V)^2/9266...
Dear friends,
Cooling water return header pressure is 1.2 kscg (at ground level). From this point, a tapping is to be taken to take 200 M3/hr of water to a distance of 650 mts(for further treatment). Following is the piping layout:
90°C bend - 35 Nos.
45 °C bend - 5 Nos.
Gate valves...
Hello all,
Urea solution (99.5% CONC,1.221sg) flows from prill tower from 170 feet elevation through 2" dia SS pipe(40 sch) to 70feet elevation. At 70 feet elevation (horizontal pipe)Press. Gauge shows only 0.5 ksc against the calculated value of 3.72ksc.There is no flow indication at both...
Dear friends,
An air compressor second stage intercooler data sheet indicates that the air moisture content is 1513 Kg/hr. But as per my calculation, it is only 1415.6 Kg/hr. Following are the calculation details :
Dry air flow First stage =61600.0Kg/Hr
First stage outlet air...
Dear friends,
To calculate thermal conductivity value of organic liquids I found the following formulae in April 12,1975 issue of Chemical Engineering. Is it can be used to calculate thermal conductivity value of SAE 10W oil.
K =0.000877 x Density^(0.83) x (293/T)^(0.38) Cal/(s-cm- °C)
Cp...
Dear friends,
How to go about calculation of LMTD(corrected) for STHE in the presence of noncondensables.I have no problem without the presence of noncondensables.
Thanks in advance to all.
We have a horizontal centrifugal pump for ammonia service. Pump is taking suction from a horizontal cylindrical tank located at 20.0 feet elevation(from tank bottom).
Pump suction pressure : 279.7 psiA
Temperature : 100°F
Sg : 0.58 4
Vapour pressure at 100°F : 212 psiA...
Dear friends,
I have a urea solution pump(135 deg c) that develops 15Kscg pressure and 15M3 flow. I want to use this pump for 5.0Kscg pressure and 15M3 flow(135 deg c). How I can control the pressure(In the new application 15 kscg pressure is not acceptable).Restriction orifice will help...
