Abstract: The invention relates to a crushing or grinding element for drum refiners having an engine-driven rotor for the crushing or grinding of fibrous materials. The element is attachable to the rotor shell and has crushing or grinding surfaces of increasing diameter and optionally crushing or grinding surfaces of steeper inclination to the rotor axis immediately adjacent the crushing or grinding surfaces inclined to the rotor axis provided on the rotor shell. The grinding surfaces are symmetrical to the median plane of the material feed. The invention is characterized in that the crushing or grinding element(s) is (are) formed as (a) segment(s) placed around the circumference of the rotor having anchoring projections of hammerhead-like cross section on the side facing the rotor axis and which are engageable in corresponding rotor grooves of hammerhead-like cross section.

Abstract: A drum refiner for grinding fibrous material, preferably chips, has an engine-driven drumshaped rotor which is placed on a horizontal shaft. The rotor has grinding surfaces extending parallel to the rotor axis and corresponding opposing grinding surfaces arranged on the housing. The grinding elements are placed symmetrically about at least one material feeds which are conveniently evenly distributed around the circumference of the rotor. The grinding surfaces begin parallel to the axis and contiguously increasing in inclination forming a grinding gap inclined towards the rotor axis at an angle of approximately 5.degree. to 45.degree., preferably 15.degree.. The second embodiment includes grinding surfaces contiguously increasing in inclination and ending with an angle of inclination of approximately 90.degree. to the rotor axis.

Abstract: A grinding element for a drum refiner for the crushing or grinding of fibrous material. The drum refiner includes an engine driven rotor having a generally horizontal rotor axis and at least one material feed. A rotor jacket is positioned on the rotor and has a surface of revolution. The grinding element is attachable to the rotor jacket on the surface of revolution and has a diameter increasing away from the material feed. A housing receives the rotor and rotor jacket therein, and has an opposing inner wall with a corresponding grinding element thereon. The grinding element on the rotor jacket includes a channel spaced from the material feed for the discharge of steam. The channel has one end in fluid communication with the grinding gap and a second end in fluid communication with a bore extending generally normally to the channel. The bore is in fluid communication with a cavity in the housing. The improvement comprises the grinding element on the rotor jacket being generally formed of a segment.

Abstract: The invention relates to an apparatus for the crushing or grindign of fibrous material, in particular fibrous material wet or mixed with water, preferably chips, in particular to drum refiners.The invention is mainly characterized in that channels for the discharge of steam are provided spaced from at least one material feed extending radially to the rotor axis or tangentially to the rotor jacket or housing shell on the grinding surfaces and optionally on the jacket supporting them, the channels piercing the grinding surfaces and optionally their supports and being provided in the working area of the grinding element provided on the surfaces, conveniently surfaces of revolution, in particular frustoconical surfaces, inclined to a rotor axis or extending normally thereto, and emptying into channels optionally provided in the bottoms of the supports and extending normally to the channels and conveniently being connected to cavities in the housing.

Abstract: The combustion gas passages leading to a fluidized bed in a hot water or steam boiler are kept free of deposits which might block them by pulses of gas. The gas pulses may be generated from a pressurized reservoir with periodic or aperiodic openings of a valve in a gas line leading from the reservoir to the passages. Where the bottom of a fluidized bed comprises a pair of plates defining a plenum space therebetween and the combustion gas passages define nozzles extending through the plenum space, combustion air may be fed to the nozzles via the plenum space and the cleaning pulses may also be generated from gas supplied to the plenum space.

Abstract: A heat exchanger for recovering the heat energy content in furnace waste gases and for recovering much of the dust entrained therewith includes a hollow duct through which the waste gases pass, and which contains first and second tube bundles arranged one after the other and a dust collection surface therebetween. The heat content in the waste gases is transferred to water passing through the two tube bundles and dust is deposited on the dust collection surface.

Abstract: Condenser for a gaseous media such as steam, comprising a plurality of longitudinal tubes, generally several thousands, through which a coolant passes. Steam is passed around these tubes, and the tubes are braced at selected locations in longitudinal direction by means of brace plates or the like, and the steam is passed from the periphery of the heat exchanger and toward the interior thereof during condensaton. The condenser comprises a casing or shell and one or more nests of tubes and means for circulating steam around the entire or greater part of the periphery, and within each tube nest, an air-cooler device is placed centrally or substantially centrally, which air-cooler extends along the entire length of the tube nest. The brace plates are provided with flow channels effective to distribute the gaseous media about the condenser in response to fluctuation in condensing capacity along the tube nests.