Claims
- 1. An installation for the chemical conversion of a gas mixture containing hydrogen and hydrocarbons, comprising a series of reactors having means for subjecting a gas mixture containing hydrogen and hydrocarbons to endothermic reactions at temperatures within the range of about 350.degree. C. to 900.degree. C. under high pressure and in the presence of a catalyst, and a plurality of furnaces with one of said plurality of furnaces being located before and in flow communication with each reactor in order to heat the gas mixture prior to introduction into its respective reactor, wherein each one of said plurality of furnaces is constituted by means defining an enclosure which has a lower inlet and an upper outlet for a gas mixture and contains bare electric resistors and conductors for the supply of electric current to said resistors, wherein each one of said plurality of furnaces further comprises a central duct having a lower end directly connected to said lower inlet and an upper end facing said upper outlet, said central duct having therein a plurality of superposed modules which are removable independently of each other, each module comprising a plurality of electric resistance elements, each said plurality of electric resistance elements being made up of banks of metallic strips, said strips being parallel to each other and to the direction along which a gas mixture flows between said inlet and said outlet of the means defining an enclosure, said strips having cut-out portions which permit enhanced resistance per unit area without affecting the free flow of gas to be heated between said strips, a peripheral zone within each one of said plurality of furnaces and surrounding said central duct, each said peripheral zone containing the conductors for the supply of electric current to the resistance elements, and a plurality of passages formed between the central duct and the peripheral zone in order that a small proportion of a gas flow which passes through the central duct may be permitted to flow within the peripheral zone.
- 2. An installation for the chemical conversion of a gas mixture containing hydrogen and hydrocarbons, comprising a series of reactors having means for subjecting a gas mixture containing hydrogen and hydrocarbons to endothermic reactions at temperatures within the range of about 350.degree. C. to 900.degree. C. under high pressure and in the presence of a catalyst, and a plurality of furnaces supplied with a fossil fuel with one of said plurality of furnaces being located before and in flow communication with each reactor in order to heat the gas mixture prior to introduction into its respective reactor, wherein said installation further comprises a plurality of electric furnaces, each one of said plurality of electric furnaces being connected in parallel with a respective one of said plurality of furnaces supplied with fossil fuel, each one of said plurality of electric furnaces comprising means defining an enclosure which has a lower inlet and an upper outlet for a gas mixture and contains bare electric resistors and conductors for the supply of electric current to said resistors, wherein each said electric furnace further comprises a central duct having a lower end directly connected to said lower inlet and an upper end facing said upper outlet, said central duct having therein a plurality of superposed modules which are removable independently of each other, each module comprising a plurality of electric resistance elements, each said plurality of electric resistance elements being made up of banks of metallic strips, said strips being parallel to each other and to the direction along which a gas mixture flows between said inlet and said outlet of the means defining an enclosure, said strips having cut-out portions which permit enhanced resistance per unit area without affecting the free flow of gas to be heated between said strips, a peripheral zone within each said electric furnace and surrounding said central duct, each said peripheral zone containing the conductors for the supply of electric current to the resistance elements, a plurality of passages formed between the central duct and the peripheral zone in order that a small proportion of a gas flow which passes through the central duct may be permitted to flow within the peripheral zone, and means for selectively flowing a gas mixture either through the furnaces supplied with fossil fuel or through the electric resistance furnaces, and then to each said reactor.
- 3. An installation according to claim 2 for the catalytic reforming of naphtha, comprising heat exchange means comprising a first heat exchanger located upstream of that pair of fossil fuel and electric furnaces which is located upstream of the first of said series of reactors for heat transfer between a gas mixture to be introduced into said series of reactors aand a gaseous effluent discharged from said series of reactors, said heat exchange means further comprising a bypass conduit in which said electric furnace of said pair is located, and at least one second heat exchanger disposed in said bypass conduit between an outlet of said first heat exchanger and said lower inlet of said electric furnace of said pair, said at least one second heat exchanger being constructed and arranged to effect a complementary heat transfer between a gas mixture introduced into said bypass conduit and a gaseous effluent discharged from said series of reactors.
- 4. An installation according to claim 3, further comprising means for passing a gaseous effluent from said series of reactors selectively either into said at least one second heat exchanger and thereafter into said first heat exchanger when at least part of the electric furnaces are put into service, or directly and solely into said first heat exchanger when the furnaces supplied with fossil fuel are all in service.
Priority Claims (1)
Number |
Date |
Country |
Kind |
83 02764 |
Feb 1983 |
FRX |
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Parent Case Info
This application is a continuation of application Ser. No. 581,046 filed Feb. 17, 1984, and now abandoned.
US Referenced Citations (10)
Continuations (1)
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Number |
Date |
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Parent |
581046 |
Feb 1984 |
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