Graphite heat exchangers: recommended tube types and block configurations
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Create a new project; the products are not fixed. For large-scale heat exchange equipment, I’d like to ask the experts on this forum: what are the advantages and disadvantages of plug-and-plate heat exchangers and shell-and-tube heat exchangers? It mainly comes down to the failure rate – which one is more reliable? What are all the reasons for this?
If a medium has to be specified, a reference condition can be provided: on the process side, it is gaseous toluene at a temperature of around 120°C; on the auxiliary side, there is cooled water at 30°C under normal pressure, with the gas flow rate being unknown. I’m just wondering if there are any experts who have used tubular and plug-and-port graphite heat exchangers, and what their most straightforward opinions on these two types of heat exchangers are. I maintain a neutral attitude toward manufacturers and designers, as the continuous tracking of customer feedback in China is not particularly good
We have also manufactured graphite heat exchangers in the past; when it comes to the heat exchange efficiency of round blocks versus tube-type designs, it is advisable to choose the round block type! In terms of price, shell-and-tube types are cheaper, but leaks can occur at the junction where the tubes meet the graphite tube sheet! Graphite materials are seeing rapid growth these days, so their prices must be high as well! For subsequent repairs, the circular blocks need to be sent back to the factory for repair, which takes a long time! The tube bundles can be disassembled on-site for pressure testing and leak sealing. Both of these types of heat exchangers have one drawback: in cases where the water quality is poor, scaling occurs severely (the circular components can be sent back to the factory for cleaning and treatment, but it’s more difficult to clean the tube bundles). Let’s compare the waste. If the equipment is scrapped, the price at which the round blocks are sold is much higher than that of the coiled tubes! Appendix: If a graphite heat exchanger is used in this process and it can ensure a service life of over 3 years, then it can be chosen. If that’s not sufficient, you might consider a PTFE heat exchanger. I hope this helps
Silicon carbide is relatively expensive, and its heat transfer performance is not particularly excellent. If it’s silicon carbide, I might consider special metals such as titanium
Silicon carbide has a much better heat transfer efficiency than metals and titanium, with a heat transfer coefficient of 1200–1400 W/㎡*K.
This post was last edited by The sun has a pleasant scent on 2018-3-24 14:09. I would like to know where this number comes from It would be convenient to provide it to me so I can study it*. From various sources, I have learned that the heat transfer coefficient of silicon carbide is comparable to that of graphite, around 850–900. So I’m asking presumptuously. Learn more*
If a graphite heat exchanger is chosen. You can talk to me
To determine whether to use circular blocks or tube bundles, one must first consider the material involved, which relates to the choice of resin impregnant. In your case, it’s gaseous toluene, and the temperature is relatively high; fortunately, it is used for cooling purposes. General leaks in the block type and tube bundles can be repaired at the customer’s site. The block type has a modular design, which facilitates maintenance, while tube bundles require longer maintenance intervals. Compared to blocks, tube bundles are prone to sudden shutdowns and startups, which can easily cause damage to the tube sheet; once the rate of tube failure increases, the heat exchange efficiency suffers significantly. Blocks perform better in terms of temperature resistance and impact resistance. Tube bundles are generally used in the phosphate fertilizer industry. If you have chosen the block type, it is recommended to return the equipment to the factory for maintenance and impregnation after two years