Abstract A method for rapid cooling of high temperature reaction gases obtained by ermal cracking of hydrocarbons, which comprises conducting an indirect heat exchange between a high temperature reaction gas obtained by thermal cracking of a hydrocarbon and a molten metal maintained at a prescribed temperature, lest heavy components in the high temperature gas be substantially condensed. In this method, the molten metal can be circulated by the use of a pressurized inert gas. In practice of this method, there can be effectively used a high temperature reaction gas cooling apparatus comprising a double-tubular heat exchanger, a cooling tank connected to said heat exchanger, and an inert gas circulating passage connected to a conduit connecting said heat exchanger and said cooling tank.
In an indirect method of rapid cooling of high temperature reaction gases containing heavy components which can form coke on heat exchanger walls and having a temperature of at least about 750° C and obtained by thermal cracking of hydrocarbons by passing said gases through a rapid cooling countercurrent flow heat exchanger cooled by a liquid heat exchange medium, the improvement comprising the steps of circulating a molten metal heat exchange medium between a cooling tank and said rapid cooling heat exchanger and introducing said molten metal medium into said rapid cooling heat exchanger countercurrently to said reaction gases at a temperature selected within the range of about 380°-550° C and above the dew point of the cokable components in said reaction gases.
Claim 2
Dependent Claim
123 words
In an indirect method of rapid cooling of high temperature reaction gases containing heavy components which can form coke on heat exchanger walls and having a temperature of at least about 750° C and obtained by thermal cracking of hydrocarbons by passing said gases through a rapid cooling countercurrent flow heat exchanger cooled by a liquid heat exchange medium, the improvement comprising the steps of circulating a molten metal heat exchange medium between a cooling tank and said rapid cooling heat exchanger and introducing said molten metal medium into said rapid cooling heat exchanger countercurrently to said reaction gases at a temperature selected within the range of about 380°-550° C and above the dew point of the cokable components in said reaction gases.
Claim 3
Dependent Claim
25 words
A method according to claim 1 wherein said molten metal is selected from the group consisting of lead, lead alloy, tin, tin alloy and bismuth.
Claim 4
Dependent Claim
37 words
A method according to claim 1 wherein said molten metal is molten lead and the temperature of said molten lead is adjusted to 380° to 400° C at the inlet and to 480° C at the outlet.