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A method for producing a cellular wheel, wherein a tool having a cylindrical inner shell, the diameter of which corresponds to the inner diameter of the subsequent sleeve, is placed on the free end edges of the fins for fixing the angular orientation of the fins. A molding material mixture is applie

A method for producing a cellular wheel, wherein a tool having a cylindrical inner shell, the diameter of which corresponds to the inner diameter of the subsequent sleeve, is placed on the free end edges of the fins for fixing the angular orientation of the fins. A molding material mixture is applied in the cells bounded by the inner shell of the tool and the fins and cured. After removing the tool, the subsequent sleeve is placed on the free end edges of the fins fixed in place by the cured molding material mixture. The free end edges of the fins are joined to the subsequent sleeve to the cells. The cured molding material mixture is thermally treated and is removed from the cells.

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1. A method for producing a cellular wheel from metal, having sleeves which lie concentrically with respect to a rotational axis and fins, which are arranged between sleeves which follow one another, are oriented radially with respect to the rotational axis, are joined with an end edge to a sleeve,

1. A method for producing a cellular wheel from metal, having sleeves which lie concentrically with respect to a rotational axis and fins, which are arranged between sleeves which follow one another, are oriented radially with respect to the rotational axis, are joined with an end edge to a sleeve, and are fixed in their angular position before the joining of the free end edges to a following sleeve, wherein (a) placing a tool onto free end edges of the fins with a cylindrical inner circumferential face, the diameter of which corresponds to the internal diameter of the following sleeve, in order to fix the fins in their angular position,(b) introducing a molding material mixture comprising a fire-resistant basic molding material and a binding agent which can be hardened and can be released from the basic molding material by thermal treatment into cells, which are delimited by the inner circumferential face of the tool and the fins, and hardening said molding material mixture,(c) after the removal of the tool, placing the following sleeve onto the free end edges of the fins which are fixed in their angular position by the hardened molding material mixture,(d) joining the free end edges of the fins to the following sleeve by welding or brazing to the cells, and(e) thermally treating the hardened molding material mixture and removing the basic molding material from the cells,wherein the tool has longitudinal grooves which emanate radially from the inner circumferential face and into which the free end edges of the fins which have an oversize are inserted before the introduction of the molding material mixture, andwherein the oversize of the fins which projects out of the hardened molding material mixture after the removal of the tool is removed before the following sleeve is placed onto the free end edges of the fins. 2. The method as claimed in claim 1, wherein the inner circumferential face of the tool has bead-like elevations on both sides of the longitudinal grooves. 3. The method as claimed in claim 1, wherein the thermal treatment is carried out on the finished cellular wheel and the basic molding material is removed from all cells at the same time. 4. The method as claimed in claim 1, wherein the finished cellular wheel is subjected to stress-relief annealing. 5. The method as claimed in claim 4, wherein the hardened molding material mixture is removed from the cells of the cellular wheel after the stress-relief annealing. 6. The method as claimed in claim 1, wherein a core sand is used as fire-resistant basic molding material. 7. The method as claimed in claim 6, wherein said core sand is a quartz sand. 8. The method as claimed in claim 1, wherein the binding agent is an organic binding agent, in which the hardening reaction is accelerated by a gaseous catalyst or which is hardened by reaction with a gaseous hardener. 9. The method as claimed in claim 8, wherein a two-component system with a solution of a polyol first component and with a solution of a polyisocyanate as second component is used as binding agent, and a gaseous tertiary amine is guided through the molding material mixture for hardening. 10. The method as claimed in claim 9, wherein said polyol is an phenolic resin. 11. The method as claimed in claim 9, wherein said gaseous tertiary amine is triethylamine. 12. The method as claimed in claim 1, wherein the fins are joined to the sleeves by welding or brazing by means of a laser or electron beam. 13. The method as claimed in claim 1, wherein the sleeves and fins are composed of a highly heat-resistant metallic material made from metal sheet. 14. The method as claimed in claim 1, wherein the sleeves and fins are composed of a highly heat-resistant metallic material made from metal sheet with a thickness of less than 0.5 mm.