Cooling screen with variable tube diameter for high gasifier power

An entrained-flow gasifier for the gasification of fuels in dust or liquid form using a free oxygen-containing gasifying agent at pressures between atmospheric pressure and 8 MPa and at gasification temperatures between 1200 and 1900° C., comprising:

• a reaction chamber connected to a quenching chamber arranged therebelow via a guide pipe in a pressure shell,
• a cooling screen, wherein the reaction chamber is delimited by the cooling screen,
• a gasification burner configured to be arranged at the upper end of the reaction chamber,
• wherein a cooling screen gap between the cooling screen and pressure shell is flushed with an inert gas,
• wherein the cooling screen is configured by the winding of a number of cooling screen tubes through which a cooling liquid flows,
• wherein the cooling screen has a tapering conical cooling screen portion at the upper end, a tapering conical cooling screen portion at the lower end and a central cylindrical cooling screen portion therebetween,
• wherein the cooling screen tubes are configured as a thick-walled cooling screen tube in the region of the lower and the upper cooling screen portion and as a thin-walled cooling screen tube in the region of the central cooling screen portion.