Calcining calcium sulphate dihydrate
AssigneeBPB Industries Limited
InventorsJames S. George, Arthur G. T. Ward, Percy N. Pastakia
Life of this patent
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Abstract
A method and apparatus for calcining calcium sulphate dihydrate in a calcination vessel in which the dihydrate is heated in the vessel to calcination temperature not only by heat applied to the exterior of the vessel but also by hot gas, especially hot gaseous combustion products, supplied into the interior of the mass of calcining material within the vessel. The supply of hot gas according to the invention can improve the production rate in both batch and continuous calcination operations without adversely affecting the product quality, by permitting increase in the heat input to the vessel without entailing the risk of vessel bottom burn-out.
Claims7
Apparatus for calcining calcium sulfate dihydrate (gypsum) comprising an open-topped, closed-bottom, calcination vessel adapted to contain a mass of calcining gypsum having a lid thereon to close said vessel;
- a combustion chamber located beneath the closed bottom of said vessel and a heat source means in said combustion chamber to supply heat to the exterior of said vessel;
- inlet means adapted for feeding raw gypsum into said vessel;
- a heat-supplying tube mounted in the lid and extending into said vessel, said tube having a closed end, an open end and distribution holes near the open end with said open end and distribution holes placed in the interior of said vessel;
- a source of hot combustion gases located near the closed end of said tube whereby said hot combustion gases pass through said tube and are directly introduced into the interior of said vessel through said open end and said distribution holes of said tube and into the mass of gypsum;
- agitation means mounted on a rotatable shaft and extending into said vessel;
- and a product overflow tube leading from an opening in the side wall of said vessel.
Apparatus for calcining calcium sulfate dihydrate (gypsum) comprising an open-topped, closed-bottom, calcination vessel adapted to contain a mass of calcining gypsum having a lid thereon to close said vessel;
- a combustion chamber located beneath the closed bottom of said vessel and a heat source means in said combustion chamber to supply heat to the exterior of said vessel;
- inlet means adapted for feeding raw gypsum into said vessel;
- agitation means mounted on a hollow, rotatable shaft and both the agitation means and the bottom portion of the hollow rotatable shaft extend into the interior of said vessel, said hollow rotatable shaft also serving as a heat-supplying tube with distribution holes located in the wall of the bottom portion of the shaft;
- a source of hot combustion gases located near the closed end of said hollow shaft whereby the hot gases are directly introduced into the interior of said vessel through said distribution holes and into the mass of gypsum;
- and a product overflow tube leading from an opening in the side wall of said vessel.
Dependencies are inferred from the claim text.