Minimizing coke buildup in transfer line heat exchangers
US4703793A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 13, 1986 |
| Grant date | Nov 3, 1987 |
| Priority date | — |
| Expiry date | Jun 13, 2006 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S165/907
- WIPO fieldThermal processes and apparatus
- WIPO sectorMechanical engineering
Abstract
Shell-and-tube transfer line heat exchangers having heat exchange tubes contained within an outer shell and a primary tubesheet, to minimize inlet end fouling, are disclosed. The exchanger includes: a secondary porous tubesheet, through which a reactive gas, e.g., an oxidizing gas such as air, oxygen, steam or mixtures thereof or a reducing gas such as hydrogen, carbon monoxide or mixtures thereof, can diffuse in amounts sufficient to react with coke deposits on the porous tubesheets process gas inlet side; the porous tubesheet is positioned preferably, but not necessarily, substantially parallel to the heat exchanger's process gas inlet end primary tubesheet nearer the inlet ends of the heat exchange tubes than the primary tubesheet and is, like the primary tubesheet, perforated by the heat exchange tubes, thus creating, with the heat exchanger's outer shell and the primary tubesheet, an enclosed space, and at least one gas inlet communicating with the enclosed space through which the reactive gas is fed. Methods of quenching high temperature gases while recovering useable heat therefrom using these transfer line heat exchangers are also disclosed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.