Abstract: A heat recovery unit is adapted for installing in a cookery cupboard or the like space in a dwelling. Within a casing (3) the unit has a lamella heat exchanger (1), which is arranged on one corner edge and has two of its defining surfaces provided with openings for passages facing upwards and two downwards. The heat exchanger has its end walls (8) oriented in vertical planes. It is adapted for heating supply air (9, 10) through heat take-up from exhaust air (11, 12). Four vertical wall portions (13, 16) form a cross above the heat exchanger, thus providing four chambers for the ingoing and outgoing air flows (9-12). By means of portions airtightly sealed against the casing (3) and wall portions (13-17) the heat exchanger is divided into two portions, each having a cross-stream course between supply air (9, 10) and exhaust air (11, 12), with its passages for supply air and exhaust air arranged in series with the corresponding passages of the other portion.

Abstract: A method and apparatus in defibration of wood chips or similar vegetable material for conveying in steam pulp produced in a refiner (2) to a separator (7) for separating steam and pulp. The separator is bounded against the atmosphere and is kept pressurized by steam, while a limited amount of excess steam is led off. A flow of steam liberated from the pulp is taken from the separator and given an increased pressure for utilization in extracting pulp from the refiner. The steam flow is hereby led through the refiner and further to the separator, whereby the pulp is transferred to the separator by the steam which thus circulates to a considerable extent, said steam having been given the higher pressure either in the refiner itself, by means of pressure increasing means (19) therein, or upstream of the refiner in a separate pressure increasing means (11).