摘要 |
The efficiency of heat transfer to a furnace tube or coil in a furnace for cracking ethane, propane or naphtha feedstocks, or a mixture thereof may be improved by providing protuberances on the surface of the tube or coil having i) a maximum height from 3 to 15% of the coil outer diameter, ii) a contact surface with a coil, or a base, which area is 0.1%-10% of the coil external cross section area, and iii) a geometrical shape which has a relatively large external surface containing a relatively small volume.
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