Patent · US Expired

Furnace having tubes for cracking hydrocarbons

US5206880A · kind A · utility

41Cited by
13References
6Claims
0Family size

Assignee

Inventor

Key dates

Filing dateMay 13, 1991
Grant dateApr 27, 1993
Priority date
Expiry dateMay 13, 2011

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY10T428/31688
  • WIPO fieldBasic materials chemistry
  • WIPO sectorChemistry

Abstract

A furnace for cracking of hydrocarbons, comprising one or several tubes through which the hydrocarbons flow during intensive heating and subsequent cracking. The starting material for the process can be e.g. naphtha or propane, mixed with a small amount of steam. When gases flow through the tube or tubes in the furnace, its temperature is increased up to about 850.degree. C. In order to achieve this, the temperature in the furnace compartment is 1100.degree.-1200.degree. C., and the temperature of the gases in the tubes in the furnace can then exceed 1100.degree. C. The tubes are made from an alloy comprising 15-30 weight % chromium, 3-10 weight % aluminum, the remainder of the composition being mainly iron. This alloy allows significant extension of the possible duration of operation without exchange of the tubes. A further improvement can be achieved by the formation on the inner walls of the tubes of a layer of aluminum oxide, obtained by oxidation of the tubes before the furnace is first used. The tubes are preferably seamless, and formed by extrusion of powder metallurgical billets.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.