Improvements in chemical and/or heat recovery apparatus for treating waste liquor

摘要

Apparatus for treating waste liquors containing combustible matters such as the residual liquors in the sulphate, soda or sulphite process of manufacturing paper pulp comprises a furnace chamber into which residual liquor is introduced in the form of a spray to be dried and burnt, a separate boiler chamber containing a bank of vertical steam generating tubes across which hot gases pass transversely from the furnace chamber and a water-cooled throat in the path of the gases between the furnace and boiler chambers. As shown in Fig. 1, the furnace chamber is of rectangular cross section and the waste liquor is sprayed into it by a nozzle 30 of the kind described in Specification 475,548, [Group XIX], dried by ascending gases and deposited on the rear wall from which it falls when dry on to the hearth 18 where it is burnt, air for combustion being supplied to the furnace through openings 39 and 42. The walls of the furnace are lined with vertical water tubes connected up to the boiler drums and are studded at their lower and upper parts and coated with refractory material as shown in Figs. 6 and 5 respectively. The furnace gases pass through the water cooled throat 11 the entrance of which is screened by tubes and enter the boiler chamber where they pass over banks of vertical tubes 62 connected to an upper drum 60 and two lower drums 61 and also U-shape superheater tubes 68. Residues containing sodium carbonate and sodium sulphate are deposited in a hopper 75 beneath the boiler having discharge pipes 80 and partitions 76. Means are provided in the walls of the boiler chamber for removing deposits from the tubes. The gases leaving the boiler chamber pass through a tubular air heater 13 from which air is supplied to the furnace chamber. Fused residues are tapped from the hearth 18 through a spout 45. Specification 475,416 also is referred to.