Objetivo To verify the energy savings and the operating costs shown in trials in which an extrusion-type pulping machine was used instead of the conventional mill-type pulping machines. Savings of the order of 80 per cent seem feasible, although 40 per cent would already be considered as a success.The project was abandoned due to thermal degradation of the material caused by friction, against the barrel's inner wall observed during the testing of the extrusion machine. Moreover product quality was not sufficient due to lack of control of output characteristics.The conventional mill-type pulping machine is replaced by an extruder consisting of a cylinder containing an endless screw. The raw material, steam treated wood shavings and turnings, is first introduced into a compression zone in the cylinder, consisting of helicoidal and/or axial grooves on the inside of the cylinder. The shavings, softened up, pass then into the pulping and bleaching section of the cylinder. The pulping is effected by the compression of the raw material against studs located on the inside cylinder walls in gaps available along the screw thread and pointing towards the cylinder axe. The quality of the pulp (number of fibrous aggregates, length and thickness of the fibres) will depend in part on the number and the distribution of the studs. There is a choice of 3 methods to inject the liquids (bleaching agents and others) into the system. The measuring will consider the energy consumption, the average yield, the characteristics of the pulp and its componentsand the quality of the fibres. The energy balance is as follows: energy consumption of a conventional mill-type pulping machine: 1.500 Kwh/ton of pulp - forecasted energy consumption for an extruder: 250 Kwh/ton, i.e. a saving of 1.250 Kwh/ton.The above project involves a production of 10.500 tons/year representing a potential saving of 13 million Kwh/year. Pulp production in 1981 was 1.2 million tons in Germany and 2.52 million tons in the EEC. Programa(s) ENG-ENALT 2C - Programme (EEC) of demonstration projects relating to the exploitation of alternative energy sources and to energy saving and the substitution of hydrocarbons, 1983-1985 Tema(s) 3.2 - INDUSTRY Convocatoria de propuestas Data not available Régimen de financiación DEM - Demonstration contracts Coordinador BERSTORFF Aportación de la UE Sin datos Dirección AN DER BREITEN WIESE 3/5 3000 HANNOVER 61 Alemania Ver en el mapa Coste total Sin datos
