By using steam on the inside of the tubes and the material to be processed on the outside in a tubular heat exchanger, can scaling and crystallization be prevented?
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For tubular heat exchangers, since the material tends to crystallize, steam is used on the inside of the tubes while the material is on the outside. Is this approach feasible? Are there relevant materials and practical verifications? I need experts’ advice!
The approach of using steam inside the tube and the material outside the tube is a viable option
Are there any advantages? Could you introduce it?
Materials that tend to crystallize and form scale should flow inside the tubes, while steam flows outside the tubes; this facilitates cleaning and the replacement of the tube bundle. If materials prone to crystallization and scaling are used in the shell side, then once crystallization and scaling occur, the entire heat exchanger becomes unusable.
The material tends to crystallize, but the steam inside the tube can melt it quickly
Why do the two answers differ?
This is unreasonable. The material should use the pipe side. Since the material tends to crystallize, increasing the flow rate in the tube side can reduce the degree of crystallization, as well as facilitate cleaning and maintenance. If the material is used in the shell side, once crystallization occurs, there is no effective way to clear it out
The material flows through the tube side, while steam flows through the shell side; since the material tends to crystallize, it is easier to clean the tube side, and it is also simpler to remove condensate when steam flows through the shell side. This is covered in the section on heat exchangers in Chemical Engineering Principles.
The material flows through the tube side, while steam flows through the shell side; since the material tends to crystallize, it is easier to clean the tube side, and it is also simpler to remove condensate when steam flows through the shell side. Principles for selecting the tube side and shell side in heat exchangers: (1) Fluids that are dirty or prone to scaling should be placed on the tube side, as cleaning inside the tubes is easier; (2) Toxic fluids should be placed on the tube side to reduce the risk of leaks; (3) Fluids with high pressure should be on the tube side to avoid putting stress on the shell as well; (4) Corrosive fluids should be on the tube side to prevent both the tube bundle and the shell from being corroded, and it also makes cleaning and maintenance easier; (5) The fluid to be cooled should be on the shell side, as this facilitates heat dissipation and improves the cooling effect; (6) If there is a large temperature difference between the two fluids, the fluid with a higher α value should be placed on the shell side, thereby reducing the temperature difference between the tube walls and the shell walls; (7) Fluids with low flow rates or high viscosity should be on the shell side, as baffle plates can help achieve turbulence at low Reynolds numbers (Re>100), or multiple tube rows can be used inside the tubes; (8) Saturated steam should be on the shell side, as this facilitates the removal of condensate and non-condensable gases, and the steam remains clean and does not cause contamination. In practice, it is often not possible to take all of these principles into account simultaneously, as they may conflict with each other. In such cases, decisions must be made based on the actual conditions. Summary: The tube side is generally used for fluids with higher temperatures and pressures, those that are highly corrosive, dirty, prone to scaling, have specific pressure requirements, or those that tend to form crystals. Shell side: Generally, it involves fluids with high viscosity, low flow rate, and a low heat transfer coefficient