What is fouling in reboiler?

Fouling in Hydrocarbon Heat Process. Fouling describes the build-up of scaling, corrosion or sludge and debris in pipes and machines. In Oil and Gas industry this can play a big role in the processing. Depending on the composition of the hydrocarbon/crude the problems with fouling start at the well.

How does fouling affect thermal resistance?

Fouling increases the overall thermal resistance and lowers the overall heat transfer coefficient of heat exchangers. Fouling also impedes fluid flow, accelerates corrosion and increases pressure drop across heat exchangers. Different types of fouling mechanisms have been identified.

Does fouling increase with temperature?

If chemical changes occur within a fluid, the difference can result in a layer of fouling on tube or plate surfaces. For example, suspended salts may harden with an increase in temperature.

Does fouling increase pressure drop?

The buildup of fouling also reduces the cross-sectional area of the tubes or flow channels and increases the resistance of the fluid passing over the surface. These side effects combine to increase the pressure drop across the heat exchanger, reducing flow rates and aggravating the problem further.

How do you calculate fouling resistance in heat exchanger?

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

How do I reduce fouling?

The best way to avoid particulate fouling is to keep the cooling water clean and thereby prevent particles from entering the heat exchanger. However, in all cooling systems, and especially when using open cooling systems (with cooling towers), there will always be particles present in the cooling water.

How do you reduce fouling factor?

How do you find the fouling factor?

Heat exchanger fouling is caused by a variety of reasons such as corrosion, precipitation, accumulation of dirt or particles, accumulation of biological material etc….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

How do you calculate fouling resistance?

What is a high fouling factor?

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 used to reduce the effect of fouling of heat exchangers?

Choosing stainless steel for your applications can help your heat exchanger resist fouling, maintain its optimal performance and last much longer. Using scraped-surface or corrugated-tube heat exchangers can also decrease fouling.

Does fouling factor depend on temperature?

The fouling factor depends on the operating temperature and the velocity of the fluids, as well as the length of service. Fouling increases with increasing temperature and decreasing velocity.

Is a once-through thermosiphon reboiler suitable for deethanizer-strippers?

Reboil vapor is limited to about 40% of the bottoms-product rate, due to the normal limitation of 30% maximum vaporization (by weight) in thermosiphon reboilers [ 1 ]. This makes once-through thermosiphon systems appropriate only for low-boilup systems, such as strippers. Many deethanizer-strippers use once-through thermosiphon-reboiler systems.

What bottlenecked a deethanizer stripper reboiler?

This article describes a case study of a gas plant (designed by others) that was bottlenecked by the reboil system of a deethanizer stripper. The reboiler system, which consisted of two parallel, once-through thermosiphon circuits, had experienced two different steady-state conditions.

What is a preferential baffle in a deethanizer?

As part of the deethanizer stripper tower base geometry, a preferential baffle divides the tower bottom into a reboiler draw sump and a bottom product draw sump.

What is the operating pressure of the deethanizer?

The operating pressure is approximately 225 psi below the critical pressure at the deethanizer top and approximately 150 psi below the critical pressure at the deethanizer bottom; therefore, phase separation is still effective.