Abstract: An absorber (10) of an absorption refrigerating apparatus is constituted by two joined plates (52 and 54, respectively), which between themselves form a plurality of horizontal ducts (60) located above each other for the refrigerant. The bottom of the ducts shows small openings (64), through which the absorption liquid leaks down into the roof of ducts located below and moves downwards along their roofs and walls.

Abstract: A device for automatic reignition of an extinguished gas flame in a burner. The burner (10) is connected to a gas source via a security valve (13) operated to its closed position by the action of spring means. By magnetic means the security valve can be kept in its open position under the influence of the EMF generated by a thermocouple (25) heated by the gas flame. An igniter (20,21) is activated by an electronic control arrangement (22) upon the latter detecting changes of a predetermined rate of change in the EMF generated by the thermocouple.

Abstract: A water tube boiler comprises a furnace having a burner and a vertical flue gas stack located to one side of the furnace. A convection tube assembly is arranged in the stack for the recovery of heat from flue gases passing through the flue gas stack. With the object of facilitating any repair work needing to be performed on the convection tube assembly, the tube assembly comprises by a plurality of parallel rows of vertical convection tubes which are provided externally with surface enlarging elements e.g. in the form of pins, along part of the height of each tube. The tubes in each row are joined together to form a coherent flat unit with the aid of a respective upper, horizontal header to which all convection tubes in the row are connected at their upper ends, and a respective lower horizontal manifold to which the bottom ends of the tubes in the row are connected.

Abstract: A telescopically extensible drill comprises a drill barrel, a drill bit connected to the barrel, and a drill rod which can be displaced between two longitudinally spaced positions in relation to the drill barrel, and secured in either of those positions. The drill can thus be extended in length without having to splice additional barrels or rods to the drill.

Abstract: A tube (10) in a heat exchanger, along which a gas transporting heat travels perpendicular to the longitudinal axis of the tube is provided with surface enlarging elements in the form of pieces of metal (11) having a width (B) substantially equivalent to twice the outer diameter of the tube, and a depth equivalent to approximately half its width. One long side of the piece of metal (11) is provided with a circular recess fitting the tube and extending through an angle of less than 180.degree., and the long edge of the piece of metal facing away from the tube is provided with three slits (14, 15, 16). One of these slits is located centrally and the other two are placed so that the metal tongues (17) produced are substantially equal in width. The central slit is deeper than the others.

Abstract: An apparatus for driving an upwardly directed shaft in rock, which includes a platform that can be regulated in height. The platform carries a drilling unit having engageable elements enabling fixation of the drilling unit relative the wall of the shaft. The drilling unit and platform can be separated a given distance such as to form an air gap for preventing the transfer of vibrations from the drilling unit to the platform when a drilling machine pertaining to the drilling unit is in operation. The apparatus has bracket elements and a transverse member for limiting the separation distance between the drilling unit and platform. The platform carries a work station for a drilling machine operator.

Abstract: A manifold receives gas streams from a plurality of gas purifiers arranged in parallel. The manifold comprises a plurality of pipe portions wiht a successively increasing diameter forming a main channel in the manifold. A first pipe portion projects into a second pipe portion, whereby, in the gap between the pipe portions a connection channel is formed which is substantially parallel to the main channel. The second pipe portion projects into a third pipe portion, thus forming a gap between the pipe portions and so on. Outlet tube portion from cyclones are connected to the connection channels.

Abstract: An electrode for electric arc processes composed of a water-cooled holder (1) into which is fitted a case hardened of diffusion coated insert of zirconium or hafnium. The diffusion zone (5) consists of carbide, nitride, boride or silicide, compounds with very high melting points that will supress reactions between the holder and the insert that cause deterioration of the electrode.

Abstract: It was found difficult to carry out anaerobic treatment of peroxide-containing wastewater. According to the invention, the problem is solved in that the peroxide content of the water is reduced in a catalytic pretreatment step (1), preferably an enzymatic pretreatment step.

Abstract: The invention relates to a method of treating wastewater from the manufacture of peroxide bleached mechanical or chemi-mechanical pulp. The method comprises a hydrolysis step, a methane fermentation steps and an aerobic step. After the hydrolysis and methane fermentation steps, sludge is separated from the wastewater and partially recycled to the hydrolysis step. The redox potential of the outgoing water from the hydrolysis step is continuously measured and controlled to a value between -400 and -260 mV by regulating the amount of sludge recycled or by passing ingoing wastewater directly to the aerobic treating step.

Abstract: At anaerobic treatment of wastewater it was found that resin and fatty acids in the wastewater have a toxic effect on the bacteria culture. According to the invention, this is solved by additions of iron or aluminium and calcium or magnesium.

Abstract: At anaerobic treatment of wastewaters from forestry industries there is the problem, that the wastewaters contain toxically acting complexing agents. According to the invention this problem is solved by the addition of a metal selected from the group iron, calcium, magnesium and aluminum.

Abstract: The invention relates to a method of treating wastewater from closed manufacture of mechanical or chemi-mechanical cellulose pulp, which treatment is carried out in a hydrolysis and acid fermentation step and a methane fermentation step with subsequent sludge separation and recycling of separated sludge.

Abstract: The digestion of the cellulose-containing material is performed with a digestion liquor containing sulphur and sodium followed by recovery and regeneration of said digestion liquor and bleaching of the cellulose-containing material with chlorine dioxide. The SO.sub.2 -containing and possibly chloride-containing gas from the recovery boiler (11) of the process and from combustion of evil-smelling gases (20) is absorbed in an absorption liquor containing and alkali metal salt solution free of sulphur or sulphur compounds such as sulphide or thiosulphate, in a scrubber (27). The resulting scrubber liquor is mixed with acid residual solution (26) from the manufacture of chlorine dioxide, whereby sulphur dioxide (32) in gaseous state is returned to the process, whereafter the residual solution (34) free from SO.sub.

Abstract: A puffer type circuit breaker is provided with a pump means consisting of a piston and a cylinder for producing a blast of arc-extinguishing gas. The piston is axially displaceable against a spring force, and the cylinder is joined to the movable contact of the circuit breaker and arranged, during a breaking operation, to compress the gas in the cylinder space of the pump means to achieve a blast of extinguishing gas towards the contact area. A spring holds the piston pressed against a stop in the closed as well as the open position of the circuit breaker. The spring has such a high pre-stress that the piston only moves upon breaking of short-circuit currents.

Abstract: A method of cooking cellulose material and effectively preserving the heat and terpentine content of the cooking liquor is disclosed. The cooking liquor is allowed to expand and the expansion steam (blow steam) is conveyed into a bed of cellulose material in a storage container (3', 3) to heat and impregnate the cellulose material before cooking. A heated zone is maintained in the bed of material below the surface of the bed by regulating the flow of expansion steam into the container. Uncondensed, evil-smelling and poisonous gases are at the same time prevented from flowing out into the atmosphere. These gases are drawn off from the storage container for destruction.

Abstract: A hardener composition for precondensates or liquid resins containing resorcinol and formaldehyde or resorcinol-phenol and formaldehyde and a method for glueing by using them. The hardener composition contains powdered paraformaldehyde suspended in a suspending agent that includes a precondensate of ketone and formaldehyde, which precondensate preferably contains water as a dilution media.