What are different types of fouling in heat exchanger?
What are different types of fouling in heat exchanger?
Feature Water & wastewater Types of heat exchanger fouling
- Chemical fouling: scaling (including limescale)
- Chemical fouling: struvite.
- Chemical fouling: vivanite.
- Biological fouling: algae.
- Biological fouling: zebra mussels.
- Biological fouling: final filtered effluent.
- Deposition fouling: sediment.
Why is fouling a problem in heat exchangers?
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.
What is the process of fouling?
In the initiation of the fouling process the interaction is between the surfaces of the heat exchanger and “particles” of foulant. Subsequently as the deposit thickens, the interaction is between the foulant material clinging to the surface and the fresh “particles” of foulant arriving at the fluid/solid interface.
What do you mean by fouling?
Fouling is the accumulation of unwanted material on solid surfaces. The fouling materials can consist of either living organisms (biofouling) or a non-living substance (inorganic or organic).
What is the purpose of a 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 minimize the frequency of cleaning.
What is the unit of fouling?
Hence the FPS unit of fouling factor is hr.
What are fouling factors?
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.
How is heat exchanger fouling determined?
How to detect fouling in heat exchangers
- Temperature transmitters. Monitor the temperature of fluids passing through heat exchangers.
- Pressure transmitters. Detect pressure drops between heat exchanger inlet and outlet.
- Flow Meters. Indicate decreases that may be caused by build-up of fouling material in pipes and plates.
What is fouling factor formula?
In the FPS system, the unit of the convective heat transfer coefficient is Btu/hr.ft².°F. Therefore unit of fouling factor is given by, Fouling factor=1h−1Btuhr. ft2. °F.
Which factors affecting fouling in heat exchanger?
Several variables contribute to fouling, including water pH, product viscosity, and the roughness of component surfaces, among many others. Together, the variables can be expressed as a fouling factor that numerically represents resistance to heat transfer — or thermal resistance — in your system.
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.
What leads to fouling?
How do you control fouling?
To mitigate the fouling rate, membrane fouling can be controlled by pretreatment of influents, optimization of operational conditions, modifying the sludge characteristics, and modifying the membrane properties.
How do you treat a fouling heat exchanger?
Perform Regular Cleanings. Cleaning heat exchangers can remove fouling and keep the equipment operating efficiently. Cleaning scale from a heat exchanger, in particular, removes mineral deposits to improve performance and decrease operational costs.