Abstract: A closure is provided for the top opening of a circular or oval cross section gas offtake pipe provided on the roof for a coke oven chamber to conduct gasses from the chamber to a gas main. The closure includes a domed top cover and an inner cover. The peripheral edge of the top cover dips into a water seal provided on the top edge of the gas offtake pipe when the cover is in a closed position. The edge of the inner cover engages a peripheral top sealing edge of an annular wall which is disposed at a distance from the water seal inwardly thereof. The top seal edge of the annular wall is disposed above a base of the water seal.

Abstract: A nozzle plate construction for underjet coke ovens for distributing and metering combustion-supporting air supplied upwardly to regenerators through a sole flue extending parallel to the chamber axis. The sole flue is closed at the top by plate elements having apertures therein. In accordance with the invention, the various plate elements are in the form of troughs having plane base plates each formed with one longitudinal gap therein. Associated with each longitudinal gap is a metering element so mounted at its ends so as to be adjustable in its distance from the plane of the base plate. In this manner, the air flowing upwardly into the regenerator sections can be accurately controlled and uniformly distributed. At the same time, the nozzle plate construction of the invention is light in weight while being very stable and easy to assemble.