Abstract: Production of plasterboard includes spreading of a mixture formed of gyps fibers and water onto a continuously moving belt to form a spread layer subsequently precompressed to 110% to 180% of a final board thickness and successively wetted from both sides and thereafter compressing the wetted layer to the final board thickness.

Abstract: Process and apparatus for the continuous production of gypsum fiber plates in which the fiber component is dewatered and rediluted with water recovered from the gypsum-fiber suspension after it has been spread on a belt, passed over at least two suction boxes and densified on the last suction box by a densifying device engaging the filter cake layer from the top.

Abstract: A process and apparatus for the continuous production of a uniform layer of oose material on a forming belt has a receiving belt onto which the loose product is deposited by a gravity chute in strips transverse to a travel direction of the receiving belt. A smoothing device above the receiving belt engages the strip layer over the entire length thereof on the receiving belt and smooths the material before it passes to a dispersing device directly or via said dispersion belt.

Abstract: The invention is directed to an apparatus for the production of plate-sha bodies from a mixture of plaster and fibrous materials. The apparatus has a conveying means, spreading means, a first and second press, an afterwetting station and a setting and drying station. The afterwetting station is located between the first press and the second press and has separate means for wetting the upper side and the underside of a raw board being processed. The separate wetting means can be independently controlled.

Abstract: Plasterboard is made by first spreading a mixture of plaster, fibers and er and then pressing this moist mixture to form the raw board. The upper and lower surfaces of the raw board are then wetted and the thus wetted raw board is pressed with a pressure less than the original consolidation pressure.

Abstract: A mixer for mortar has part of its water feed introduced between a rotating isk and the floor of the disk housing, this water being propelled outward through an annular constriction in the clearance between the disk and the housing so that the rotor is kept constantly pressured by the inflowing water. The rest of the water is introduced through inlets spaced in a ringlike arrangement in the housing cover so as to produce a continuous water film on the rotating disk, onto which the powdered plaster and any other additives are fed.

Abstract: In the process for making gypsum fiberboard the boards are formed or molded rom a mash containing calcium sulfate dihydrate and fiberous material. By heating and subsequently cooling the boards the dihydrate is first converted into the hemihydrate and subsequently recrystallized again to the dihydrate. Known processes require day line setting times which are economically disadvantageous. According to the present invention these times are shortened by pulling or drawing water, an aqueous solution or a water containing mixture through the boards after the cooling step. Advantageously a setting accelerating agent can be dissolved in the water. By these features the setting time can be shortened to less than two hours. By addition of a binding agent, e.g. starch, to the fluid drawn through the boards the strength of the boards is increased.

Abstract: A cylindrical cutter head for a wood planing machine has mounted in its cumference a number of disposable knife blades which are clamped in place with the help of centrifugal wedges in lengthwise grooves. Between each disposable knife blade and each centrifugal wedge there is positioned a bracket of L-shaped profile consisting of a base strip which is immovably attached to the cutter head body and a clamping strip bearing against the knife blade, this clamping strip being elastically deformable to a small extent. By means of a conformal relation of a profiled region of the disposable knife blade with a corresponding profiled region of the clamping strip, the disposable knife blade is held firmly in position when clamped in. After loosening of the centrifugal wedge, the disposable knife blade can be easily withdrawn in a lengthwise direction and can be replaced with accurate positioning.

Abstract: The invention relates to a continuous dryer for veneer. In addition to terature sensors near the inlet and middle zones to determine heat demand and to control heat input in these zones, the dryer also has an infrared detector at the exit end to determine surface temperature and thus to determine residual moisture of the veneer. The signal from this infrared detector is processed to give a control signal for blowers in the drying zones near the exit. By this means, more precise and reliable control in final moisture is achieved. Variations in dryer load, initial moisture, wood density, and sheet thickness can be better tolerated.

Abstract: A continuous drier for plywood sheets is provided at its inlet end with a nsing device measuring the width and the spacing of the plywood sheets entering the drier. The values measured by the sensing device are transmitted to a control device, which by means of a calculator regulates the speed of a conveyor transporting the plywood sheets through consecutive sections of the drier in such a manner that the plywood sheets follow each other closely on the conveyor without overlapping. Each of the sections is provided with a heater and a ventilator which blows air over the heater, and the hot air is directed by installations onto the plywood sheets. In order to compensate the effect of the varying speed of the conveyor with respect to the drying of the plywood sheets, the control device preferably controls also the volume of the streams of hot air by varying the speed of the ventilators. This will result in a considerable saving of the driving energy.

Abstract: In the method of feeding pulverized solid fuels into a fluidized bed hearth, the granular solid fuel is first delivered into a fuel distributing space where it is fluidized by means of a whirling stream of air and the fine granular components of the fluidized fuel are pneumatically fed through an array of feeding pipes into the fluidized bed formed in the combustion space of the hearth. The device for performing the method includes heat-resistant feeding pipes uniformly distributed between the combustion space and projecting into the fuel distributing space to immerse into the fuel distributing fluidized bed of fuel. The fluidizing air of stream is introduced into the distributing chamber to act both as the fuel conveying medium and as a combustion air in the combustion space.

Abstract: Waste gases are purged by adding to the gas while it flows through an abser a neutralizing agent together with water and then subjecting the gas to cooling so as to evaporate the added liquid. The adsorption then results in a reaction with the neutralizing agent whereby dry salts are formed which are removed from the process. The temperature of the waste gas is automatically and continuously measured and the volume of the water is adjusted automatically and continuously in accordance with the temperature measurements. The amount of waste gases is furthermore automatically and continuously measured, preferably at several places of the process, and the amount of neutralizing agent is continuously and automatically adjusted to the latter measurements so as to obtain always the stoichiometric equivalent for the reaction with the pollutants.

Abstract: Waste gases are purged by adding to the gas while it flows through an abser a neutralizing agent together with water and then subjecting the gas to cooling so as to evaporate the added liquid. The adsorption then results in a reaction with the neutralizing agent whereby dry salts are formed which are removed from the process. The temperature of the waste gas is automatically and continuously measured and the volume of the water is adjusted automatically and continously in accordance with the temperature measurements. The amount of waste gases is furthermore automatically and continuously measured, preferably at several places of the process, and the amount of neutralizing agent is continuously and automatically adjusted to the latter measurements so as to obtain always the stoichiometric equivalent for the reaction with the pollutants.

Abstract: Plyboard or the like passes through the successive drying zones of a multone drier, has a varying initial moisture content and presents to the drier a fluctuating degree of loading (surface area). The drying action is varied by adjusting the drying-gas temperature and/or the transport speed of the goods through the drier, so as to quickly match the drying action to the fluctuating drying demand. Instead of measuring initial moisture content per se and degree of loading (surface area) per se, temperature measurements are performed, from which equivalent information is derived, and from which in turn are calculated the values of drying-gas temperature and/or transport speed which must be set on the temperature and speed controllers of the drier.

Abstract: An arrangement for intercepting entrained contaminants from a gaseous medium in a scrubbing liquid has a whirling chamber, a droplet-separating passage, and an impeller arranged coaxially downstream of one another. The whirling chamber has a constant-width inner annular zone and an outer annular zone surrounding the inner annular zone and decreasing in its axial width in the radially outward direction. A housing surrounds the impeller and/or the passage and is either cylindrical or spiral-shaped or partly both, and in the latter event the differently shaped parts of the housing are separated by a partition which has a central orifice of a smaller diameter than that of the impeller.

Abstract: The scrubber has a substantially rotationally symmetrical vortex chamber provided at one end with an axial gas outlet whose diameter is substantially smaller than the diameter of the chamber. A coaxial impeller wheel is located at the other axial end of the chamber and admits into the region of the chamber periphery a stream of contaminated gas which has a component of movement in circumferential direction of the chamber. A plurality of spray nozzles spray a washing liquid into the chamber for contact with the contaminated gas therein.

Abstract: Articles to be dried are conveyed through a tentering frame in a path. Air is heated and then directed into contact with the articles in direction transversely of the path. The air is directed by at least one crossflow blower unit and a plurality of channel elements, each of which has a foraminous wall which faces the articles passing through the frame. The blower is driven by a motor drive which is operative for circulating the heated air in direction through the blower unit and into the channel elements. Thereupon, the air passes through the respective foraminous walls to impinge against and thereby dry the articles. After impingement, the air is guided away from the articles by a plurality of air outlet passages which are respectively formed between adjacent ones of the channel elements which are successively arranged along the path at a predetermined spacing from each other.

Abstract: Articles to be dried are conveyed through a tentering frame in a path. Air is heated and then directed into contact with the articles in direction transversely of the path. The air is directed by at least one crossflow blower unit and a plurality of channel elements, each of which has a foraminous wall which faces the articles passing through the frame. The blower is driven by a motor drive which is operative for circulating the heated air in direction through the blower unit and into the channel elements. Thereupon, the air passes through the respective foraminous walls to impinge against and thereby dry the articles.