For gases heated to 280–300, what is the best method?
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Heat the alkenes with carbon numbers C5 to C20 in a gas phase at a temperature between 280 and 300 degrees (not exceeding 300 degrees). If no heating furnace is used and the material flow rate is 40 tons per hour, would it be feasible to use heat transfer oil along with a heat exchanger for heating? What type of heat exchanger would be suitable in this case? (Plate type, ordinary type, or coiled tube type?), what should be the minimum temperature of the heat transfer oil in this case (310 degrees or 320 degrees?) ) Thank you
There should be at least a temperature difference of 20-30 degrees. Heat transfer oil is not recommended; a slightly higher temperature is fine, and a heating furnace can be used
The key is that the material must be heated; the reactor absorbs heat, then heating continues and the reaction takes place. At the same time, for heat-sensitive substances, the membrane temperature must not exceed 350 degrees
For heat exchangers, shell-and-tube types are a better choice; plate heat exchangers are not recommended. Regarding temperature, it is better if it is higher; since the temperature on the hot side is too low, the temperature difference for heat transfer is too small, which hinders heat transfer. Regarding heat-sensitive substances, the control valve can be adjusted through sensor feedback, thereby preventing temperature abnormalities.
For heat exchangers, shell-and-tube types are a better choice; plate heat exchangers are not recommended. Regarding temperature, it is better if it is higher; since the temperature on the hot side is too low, the temperature difference for heat transfer is too small, which hinders heat transfer. Regarding heat-sensitive substances, the control valve can be adjusted through sensor feedback, thereby preventing temperature abnormalities.
For heat exchangers, spiral tubes seem to be better, as they have a higher heat transfer coefficient
Heat transfer oil works fine; high-temperature heat transfer oil can be used up to 360°C. Steam can also be used for heating. Both can control temperature well, with steam heat transfer being more effective. A tubular heat exchanger will suffice for heat exchange; a plate heat exchanger definitely won’t work
A hot air furnace can be used, with the flue gas temperature controlled to be below 400°C, and a shell-and-tube heat exchanger is employed. The flue gas temperature at the exit of the hot air furnace is controllable, with flue gas recycling to achieve energy savings.
Heating with high-pressure steam, with stable temperature control, a shell-and-tube heat exchanger will suffice.
This issue needs to be considered comprehensively based on various factors such as the environment in which the facility is located, for example whether it is an explosion-proof area or not; in fact, there is also the issue of the heating source for the heat transfer oil itself. With this issue resolved, the selection of the heat exchanger is no longer a problem.
According to your operational requirements, heat transfer oil is used as the heat source, and its operating temperature must be around 320 degrees. You should use heat transfer oil of grade 350; heat transfer oils of higher grades require operation in a gas phase, which imposes higher demands on the heat exchanger. Since your processing scale is large, a larger amount of heat transfer oil is needed, and the higher the operating temperature of the heat transfer oil, the better. The heat exchanger must be a shell-and-tube or U-tube heat exchanger. Heating with a furnace is still quite cost-effective. Additionally, using molten salt as the heating medium and a U-tube heat exchanger as the heating device is also possible.