A tube bundle heat exchanger has tubes which are held at each side in tube plates or oval-tube collecting-tube plates and are connected to these in each case by means of a weld seam. The connection of the tubes to the inlet-side tube plate or oval-tube collecting-tube plate is formed in each case by means of a conical and/or trumpet-shaped transition piece. The cross section of the transition piece reduces as viewed in the gas flow direction in such a way that the inlet-side end, as viewed in the gas flow direction, of the transition piece is connected in a buttjoint to the tube plate or oval-tube collecting-tube plate. The inner and outer contours of the transition piece and of the welded connection region are formed without gaps and corners to the tube plate or oval tube collecting-tube plate and so as to be straight and/or with a radius, measured from the outer contour, of at least 5 mm.

A method for welding tubes in a shell and tube heat exchanger, including forming ring-shaped tube sheet grooves on the tube sheet at the shell side, inserting tube joint members into the tube insertion holes of the tube sheet, producing ring wires by cutting a welding wire into pieces and bending the pieces into a ring shape, affixing the ring wire to the outer circumference of one end of the tube, inserting the end of the tube into the tube sheet such that the end of the tube contacts one end of the tube joint member and is located within the recessed distance range of the tube sheet groove, and performing shell side welding by inserting a welding torch into the tube joint member and welding the end of the tube joint member, the end of the tube and the joint part to the tube sheet at the shell side using the ring wire as filler metal.

A manifold including a body defining a chamber configured to receive a fluid, the body having a plurality of apertures passing therethrough and a plurality of channels engaged in the apertures and configured to receive the fluid from the chamber, each of the plurality of channels having an end defining an inlet that is in fluid communication with the chamber. Each channel defines a standoff defining a portion of the channel that is not in contact with the body such that the inlet is separated from the body by a standoff distance along the length of the channel and the standoff distance is a distance that is one or more times a hydraulic diameter of the inlet.

In the production of carbon black by the furnace process, fuel and heated combustion air or oxygen enriched air from the combustion air heat exchanger, are fired into the reactor, resulting in a hot flame. Carbonaceous feed stock, injected into this hot flame containing considerable excess oxygen, is pyrolized. The effluent from the reactor reaction zone is quickly cooled, typically by water quench, to prevent secondary reactions that decrease the quality and yield of carbon black. In the present invention, water quench is eliminated and the effluent from the reaction zone passes directly into the metallic combustion airheater, quickly cooling it to stop pyrolysis and heating the combustion air to typically 950 C. The combustion air heater is smaller due to high heat flux per unit volume. Further cooling of the effluent to the carbon black collector, is achieved by series of heat exchangers and trimming water quench.

A tube bundle heat exchanger has tubes which are held at each side in tube plates or oval-tube collecting-tube plates and are connected to these in each case by means of a weld seam. The connection of the tubes to the inlet-side tube plate or oval-tube collecting-tube plate is formed in each case by means of a conical and/or trumpet-shaped transition piece. The cross section of the transition piece reduces as viewed in the gas flow direction in such a way that the inlet-side end, as viewed in the gas flow direction, of the transition piece is connected in a butt joint to the tube plate or oval-tube collecting-tube plate. The inner and outer contours of the transition piece and of the welded connection region are formed without gaps and corners to the tube plate or oval tube collecting-tube plate and so as to be straight and/or with a radius, measured from the outer contour, of at least 5 mm.