Abstract: A device for feeding and controlling secondary air from secondary air ducts into flue gas channels of horizontal coke oven chambers is shown. The flue gas channels are located underneath the coke oven chamber floor on which coal carbonization is realized. The flue gas channels serve for combustion of partly burnt coking gases from the coke oven chamber. The partly burnt gases are burnt with secondary air, thus heating the coke cake also from below to ensure even coal carbonization. Secondary air comes from the secondary air ducts connected to atmospheric air and to the flue gas channels. Controlling elements are mounted in the connecting channels between the flue gas channels and secondary air ducts which can precisely control the air flow into the flue gas channels. Thereby, it is possible to achieve a much more regular heating and heat distribution in coke oven chambers. The actual controlling devices in the connecting channels can be formed by turnable pipe sections, wall bricks, or metal flaps.

Abstract: A refractory brick is installed in a transfer flue with vertical orifices disposed between, on the one hand, the regenerators or recuperators and, on the other hand, the combustion chambers of industrial gas-fired systems, particularly a coke oven. The refractory brick has parallel surfaces and the length of the orifices in the brick is at least six times their diameter. The sum of the cross-sectional areas of the orifices is from 0.75 to 1.5 times the flow cross section of the upwardly-inclined portion of the transfer flue. The cross sections of the orifices can be cylindrical or elliptical. The orifices can be longitudinal slots whose cross-sectional areas are bounded by semicircles and whose cross-sectional length is not greater than three times the diameter of the semicircles.

Abstract: A heating flue for a coke oven includes a flow plate to replace the base in the heating flue. The thickness of the flow plate is greater than the thickness of the flue base and disposed above a chamber which is divided into two halves in a gas-tight manner by a central web of refractory material. Each chamber communicates with ducts that feed preheated air from regenerators during rich-gas firing and feed preheated air and lean gas during firing with lean gas. The height of the chamber to the thickness of the flow plate is a ratio within 0.3 to 0.7, preferably 0.5. The flow plate has a plurality of bores each with a cross-sectional area which, when compared with the cross-sectional area of the plate, forms a ratio of between 20 and 200, preferably 30 to 60. The diameter of a cylindrical bore is between 10 and 60 millimeters, preferably 20 and 50 millimeters.

Abstract: A process for reducing the nitrogen oxide content of coke oven gases by spraying ammonia or ammonia-containing water into the regenerator chambers of a coke oven where the coking oven waste gases are at a temperature of between 700.degree. and 1100.degree. C.

Abstract: The waste heat resulting from a coke oven operation is recovered in a two-stage proceeding. The waste gas is first cooled to not more than about 400.degree. C. in a recuperator or regenerator of the oven to principally utilize the heat radiation of the gas. Then, in a second stage, the gas is subjected to further cooling in a separate heat exchanger to principally exploit the heat convection of the gas. The process permits to recover waste gas on both basic principles of waste recovery, that is the recovery by radiation and the recovery by convection.

Abstract: A recuperative coke oven includes at least one recuperator chamber arranged below an oven chamber. Hot undergrate firing exhaust gas is passed from the oven through the recuperator chamber. At least one elongated recuperator extends into the recuperator chamber. The recuperator includes an inner tube and a coaxially outer tube. The inner end of the inner tube is open, and the inner end of the outer tube is closed to define an annular chamber between the two tubes. Combustion air to be heated is introduced into the inner tube and passed therethrough. The combustion air then reverses direction and passes through the annular chamber and is thereat heated by the hot exhaust gas passing through the recuperator chamber. The heated combustion air is discharged from the annular chamber and passed to the heating flues of the oven.

Abstract: In a coking operation where the heating medium is introduced into the furnace by way of a bottom fire box and wherein heat exchangers are provided for the waste gases, the waste gas is passed through a plurality of parallel channels serving as said heat exchangers and the useful portion of the total system available for such exchange is reduced when the coking time is increased beyond the time required at normal operation.