This invention relates in general to coking devices and in particular to a new and useful apparatus for generating superheated high pressure steam during a dry process of cooling the coke and to an apparatus for carrying out the method.
A method and apparatus for dry cooling incandescent coke are known from German patent application No. P 33 32 702. In this prior art method, the heat from the hot coke is partly transferred in the cooling chamber to a circulated cooling gas and used in a following waste heat boiler and, through a heat exchanger, for generating superheated high-pressure steam. The usual superheater, evaporator, and feed water preheater are provided in the waste heat boiler and connected in series. Experience has shown that the tubes in the superheater are exposed to extreme conditions. On their outside, they are in contact with the hot circulated gases having a temperature in excess of 1,000.degree. C., and inside, they are in contact with the superheated steam flowing therethrough. Also, the reducing atmosphere of the circulating hot gas require very expensive materials which must withstand these extreme temperature as well as high pressures and very corrosive gases.
German OS No. 30 07 040 discloses a method and apparatus for utilizing the sensible heat of coke in a dry cooling process with a circulated inert gas, where the hot circulated gas is directed from the cooling chamber, upstream of the boiler-heat exchanger system, through a combustion chamber into which a fuel gas and an oxygen containing gas, such as combustion air, are introducible. This additional combustion chamber is intended to ensure a continuous steam generation, if irregularities in the hot coke supply occur. In normal operation of the plant, the entire amount of circulating hot has is directed above into the boiler-exchanger system, and the gas first contacts the coils of the superheater.