Abstract: A method and system for efficient heat recovery during the production of mechanical pulp treats the process steam inherently produced during the production of mechanical pulp to maximize the energy content of clean steam produced. Comminuted cellulosic material is refined in one or more refiners, and the mixture of mechanical pulp and process steam from the refiner is separated into process steam and pulp flows by a cyclone. The process steam is passed to a scrubber, and then to an inlet of a reboiler (steam transformer) which produces clean steam and discharged flow-through process steam. The conduit between the cyclone and the scrubber is open so that the pressure of the process steam before it enters the reboiler is not significantly affected; a buffer may be provided in the conduit, however, to damp process steam pressure variations.

Abstract: In the production of mechanical pulp a refiner (defibrator) is driven by a steam turbine. The steam supply for the turbine comprises process steam generated in the refiner during the refiner action, which steam is passed through a reboiler and then superheated, in a superheater or economizer, before being supplied to the turbine. A boiler comprises a secondary source of steam and that steam too is introduced to the steam turbine, either directly or after passage through another turbine which powers an electric generator. The off-gases from the boiler may drive a gas turbine. All the components may be mounted on a train, and the gas turbine may power the locomotive for the train. The gas turbine can also power an air compressor providing compressed combustion air to the boiler.

Abstract: A tank containing a bed of particulate material, e.g. a sand filter bed or an ion exchange bed, has a bed-supporting bottom structure formed by upper and lower bottom plates rigidly connected with each other through a plurality of vertical sleeves opening into the spaces above and below the tank bottom structure. Openings in the wall of each sleeve connect the interior of the sleeve with the compartment formed between the bottom plates. A strainer unit is removably inserted in each sleeve through the lower end of the sleeve and passes liquid between the bed and the compartment between the bottom plates by way of the openings in the side wall of the sleeve.

Abstract: A tank containing a bed of particulate material, e.g. a sand filter bed or an ion exchange bed, has a bed-supporting bottom structure formed by upper and lower bottom plates rigidly connected with each other through a plurality of vertical sleeves opening into the spaces above and below the tank bottom structure. Openings in the wall of each sleeve connect the interior of the sleeve with the compartment formed between the bottom plates. A strainer unit is removably inserted in each sleeve through the lower end of the sleeve and passes liquid between the bed and the compartment between the bottom plates by way of the openings in the side wall of the sleeve. An adjustable valve member accessible from below the tank bottom structure serves to control the flow of liquid through the strainer unit.