What is the unit of fouling factor?
Hence the FPS unit of fouling factor is hr.
How do you calculate fouling resistance?
Fouling changes the surface of the wall between hot and cold fluids. As a result, the overall heat transfer rate through that surface is reduced….Typical fouling factor values.
| Fluid | Fouling Factor [(h⋅ft2⋅°F)/Btu] |
|---|---|
| Light gas oil | 0.002 |
| Heavy gas oil | 0.003 |
| Heavy fuel oil | 0.005 |
What is the fouling resistance?
The fouling factor represents the theoretical resistance to heat flow due to a build-up of a layer of dirt or other fouling substance on the tube surfaces of the heat exchanger, but they are often overstated by the end user in an attempt to minimise the frequency of cleaning.
What is fouling factor of cooling water?
COOLING WATER – Fouling Factors in
| Conditions | cooling water < 50 ° C cooled fluid < 120 ° C | cooling water > 50 ° C cooled fluid > 120 ° C |
|---|---|---|
| River mimimum | 0.00018 | 0.00035 |
| River average | 0.00053 | 0.00070 |
| Engine jacket | 0.00018 | 0.00018 |
| Demineralized or distilled | 0.00009 | 0.00009 |
What is the value of fouling factor for industrial liquids?
Explanation: Fouling factor for engine exhaust is 0.002 while that of industrial liquids, fuel oil and turbine exhaust are 0.0002, 0.0010 and 0.0002 respectively.
What is the significance of NTU?
NTU means number of transfer units. It signifies that the heat transfer capacity of a given heat exchanger. NTU signifies how much number of units of heat, the given heat exchanger is capable of transferring from one fluid to other.
What is fouling factor formula?
During operation with liquids and gases a dirt film may build up on the heat exchanger surfaces . The deposit film is referred to as fouling. Increased thermal resistance caused by the deposit can normally only be obtained from tests or experience. The fouling factor can be determined as. Rd = 1 / Ud – 1 / U (1)
What is difference between lmtd and Amtd?
Reason :- We are using LMTD to find out the average temperature difference throughout the length. We can use AMTD but it’s difficult(Not possible) to measure temperature difference throughout the length and then finding average of all of them.
What is fouling engineering?
Fouling is the settlement, and sometimes the growth, of undesired materials on solid surfaces in a way that reduces the efficiency of the affected part. It deteriorates protective coatings on the metals and reduces corrosion resistance as well as physical and mechanical properties of the material.
What is fouling factor used for?
Fouling increases with increasing temperature and decreasing velocity. As we can see fouling factor decreases the overall heat transfer coefficient deteriorating the performance of the heat exchanger. Therefore, the Fouling factor is used in heat exchanger design as a safety factor.
What is the value of fouling factor for clean river?
Explanation: Fouling factor for liquid gasoline is 0.0008 while that of clean river, sea water and distilled water are 0.0002, 0.0001 and 0.0001 respectively.
How is the value of fouling resistance calculated?
The value of fouling resistance is calculated using the overall heat transfer coefficient in clean and fouled conditions. The parameter estimation is formulated as a nonlinear constrained optimisation problem and solved using Genetic Algorithm.
What units are used to calculate the fouling factor?
The fouling factor, Rf, as well as the deposition rate, d, and the removal rate, r, can be expressed in the units of thermal resistance as m2·K/W or in the units of the rate of thickness change as m/s or units of mass change as kg/ m2· s.
Why is the fouling resistance data different for the plain probe?
When compared with the fouling resistance data found by Young et al. (2011) for the plain probe, it can be seen that there is now much more scatter in the experimental data. This is most probably due to the random removal of the deposit because of the higher shear force which is created on the wired probe at any given stirrer speed.
Are there fouling resistances in heat exchangers?
1. Data table of fouling resistances of some processing fluids Please find below a table of fluids founds in process industries and the fouling resistance it is expected they can generate in heat exchangers. Warning 2 : The data below are thus only for a 1st reference, quick calculation, but no detail design, no guarantee are given upon them.
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