Abstract: A method for continuous saccharification of plant raw material by feeding the raw material as such or prehydrolyzed and a dilute sulphuric acid solution into a flow reactor in order to hydrolyze the raw material under pressure and at a high temperature, discharging dry solids and liquid from the reactor by expansion and separating liquid and solids, wherein the raw material and sulfuric acid solution are led through the reactor at equal rate, which is the same as required by the more easily hydrolyzable particles of the raw material, the solids and liquid together are discharged into the same blow tank and at least part of the separated coarse solid is returned into the reactor.

Abstract: A method of improving the utilization of the heat energy produced in a wood grinding process when wood is ground in a grinding space (3) under a pressure exceeding atmospheric pressure, and warm shower water (G) is sprayed into the grinding space. Steam (H) is separated from the groundwood pulp (A) discharged from the grinding space in a steam separator wherein the groundwood pulp is allowed to expand from its inlet pressure to atmospheric pressure in at least two steam separators (11,14) by releasing steam from the groundwood pump in each steam separator by decreasing the pulp pressure. The amount of steam (H1,H2) released in the separate steam separators is adjusted according to the proportions in which steam is needed for utilizations purposes. Thus the heat energy of the pressure grinding process can be recovered in separate steam fractions the amount and pressure of which correspond to the requirements of the utilization purposes.

Abstract: A drill steel centralizer comprising a body having an immovable jaw positioned in stationary relation to the body. A movable jaw and drill steel guide between said jaws that can be opened and closed by means of the movement of the movable jaw. A locking device providing means by which the movable jaw can cause the drill steel guide to be locked and released into the closed and open positions. Thus, the locking device is held in its locked position by an elastic member that is arranged to transmit a force attempting to open the jaw past the elastic member directly to the body.

Abstract: A mechanism for reversing the direction of rotation in a drilling apparatus comprising a feeding beam (1) and a drilling machine (3) supported by the beam for longitudinal movement back and forth along the beam in a drilling direction (A) and an opposite return direction (B) by a feeding mechanism (4). The drilling machine is provided with a pressure medium driven rotating device (9) for rotating a drilling rod and with a reversing valve (13) connected to the pressure medium system of the rotating device. The reversing valve is provided with a spindle rotatable between two positions in which the rotating device rotates the drilling rod in opposite directions. The reversing mechanism comprises two actuating elements (24,27) rotatable with respect to each other. One element (24) is in rotational engagement with the spindle and is moved axially together with the spindle at least at the end of the return direction of the drilling machine.

Abstract: A method for improving the utilization of the heat energy produced in a wood grinding process, wherein wood is ground in a grinding space (3) under a pressure exceeding atmospheric pressure, and warm shower water (G) is sprayed into the grinding space. The groundwood pulp (A) is fed from the grinding space into a steam separator (11), wherein the heat energy contained in the groundwood pulp is released in the form of steam (H), and replacement water (E) is brought into the process for the compensation of shower water losses. The steam separator is kept pressurized in order to recover the steam (H) released from the groundwood pulp under a greater pressure and at a higher temperature than in an atmospheric steam separator.

Abstract: A method of increasing the temperature of shower water used in a wood grinding process wherein wood is ground in a grinding space (3) under a pressure exceeding atmospheric pressure, and warm shower water (G) is fed into the grinding space for improving the grinding process. In order to compensate losses of shower water replacement water (E) is added to the shower water circulating system. The replacement water is fed into the groundwood pulp (A) after the grinding space but before a steam separator. Thus cooler replacement water can be heated by the heat energy otherwise released from the groundwood pulp in the steam separator, and the temperature of the shower water can be maintained close to 100.degree. C. in spite of the addition of cool replacement water and without using a pressurized steam separator.

Abstract: A hydraulic control system for use with a rock drill is adapted to sense a pressure build-up in the drill's rotation motor and in response thereto, to reverse the direction of feed of the feed motor as well as to supply hydraulic fluid to a shank cylinder on the rock drill. Supplying hydraulic fluid to the shank cylinder assists in freeing the drill from the rock.

Abstract: A striking apparatus that includes a reciprocating striking piston operable by a pressure mechanism, a cylindrical body, the improvement comprising a sleeve bushing mounted inside of the cylindrical body in slidably fitted assembly therewith. The sleeve bushing has a drive gear at one end for rotary engagement with a drive motor. A rotary tool and piston shank and piston are all integrally combined as a one piece unit and at least partly received in coaxial alignment within the tubular bushing. Spline gearage exists between the tubular bushing and the piston shank enabling co-rotational rotary movement together upon actuation of the drive gear through operation of a drive motor operatively connected therewith. A piston cylinder in the cylindrical body along with the piston is reciprocably movable in the piston cylinder. The shank has a shank face facing in the direction opposing the striking piston and with the shank face transferring the feed force from the body through the sleeve bushing to the rotary tool.

Abstract: A hydraulic drilling apparatus, especially a rock drill comprising a body, a cylinder in the body and a percussion piston reciprocating in the cylinder. A tool is connected to the body and a motor is provided for rotating the tool. A control valve is also provided for the percussion power. A control valve is also provided for regulating the motor speed. Both of these control valves are operated independently by one lever. A hydraulically operated flushing valve is also provided. A hydraulic pump and hydraulic channels coact to form a percussion circuit and a rotation circuit is parallelly coupled with the percussion circuit in relation to the hydraulic pump. A flushing valve circuit is controlled by the percussion circuit and a circuit for the free circulation of the hydraulic pump which is parallelly coupled with the percussion circuit in relation to the hydraulic pump. The circuits are connected to the hydraulic pump.

Abstract: A hydraulic percussion apparatus comprising a body, a cylinder in the body and a percussion piston reciprocating in the cylinder. A distributing valve moves in a valve housing. A valve for starting and stopping the percussion apparatus is provided. A hydraulic pump and hydraulic channels form a percussion circuit with a gas/liquid pressure accumulator. A distributing valve circuit and a free circulation circuit are provided for the pump which are parallelly coupled with the percussion circuit, which circuits are connected to the pump and to the start-and-stop valve which has positions for controlling pressure in the circuits. The start-and-stop valve has a middle position during which pressure in the percussion circuit rises up to a predetermined value while the distributing valve circuit remains closed independent of the pressure in the percussion circuit.

Abstract: A rock drilling method according to which the drill is subjected to successive axial strikes and is rotated around its longitudinal axis. The direction of rotation is repeatedly reversed after the drill has rotated at least one revolution in one direction.

Abstract: A process for recovering lignosulfonates from spent sulfite liquor resulting from the cooking of cellulose-containing material comprising extracting the spent liquor with a liquid amine dissolved in a strongly polar ketone, preferably methyl isobutyl ketone, as an organic solvent, which ketone is poorly soluble in water, to form a lignosulfonate-bearing organic phase and an aqueous phase, separating the organic phase from the aqueous phase, recovering the substantially sugar-free lignosulfonates from the organic phase by stripping the organic phase with a base insoluble in the organic phase, regenerating the stripped, lignosulfonate-free organic phase by treating it with an aqueous solution of sodium bisulfite to bring the liquid amine in the phase into bisulfite form and returning the regenerated organic phase for further extraction of spent liquor.

Abstract: Apparatus for continuously processing wood comprises a pressurized grinding chamber, a grinding stone which is mounted for rotation in the grinding chamber, a device for feeding wood into the grinding chamber to form a primary groundwood stock therein, and a device for discharging the primary groundwood stock from the chamber without allowing gas to escape from the chamber to atmosphere. The feeding device comprises a stationary feeding chamber provided with shutters for sequentially pressure-tightly closing the feeding chamber from the atmosphere and from the grinding chamber respectively, thereby to prevent escape of gas from the grinding chamber through the feeding device.

Abstract: Apparatus for continuously processing wood comprises a pressurized grinding chamber, a grinding stone which is mounted for rotation in the grinding chamber, a device for feeding wood into the grinding chamber to form a primary groundwood stock therein, and a device for discharging the primary groundwood stock from the chamber without allowing gas to escape from the chamber to atmosphere. The discharging device comprises a stick crusher for crushing sticks present in the primary groundwood stock thereby to produce a secondary groundwood stock and an outlet for continuously discharging the secondary groundwood stock while preserving a hydraulic seal of groundwood stock thereby to maintain the groundwood stock in the apparatus under superatmospheric pressure.

Abstract: A sealing arrangement for a shutter for a feeding chamber of a continuously operating pressure grinder. The feeding chamber is provided with an inlet opening for feeding wood batches at atmospheric pressure into said feeding chamber and with an outlet opening for feeding said wood batches into the grinding chamber at overpressure. Each opening of said feeding chamber is provided with a shutter movable between an opened position and a closed position for preventing of escape of said overpressure through said feeding chamber.The feeding chamber is provided with a fixed guide supporting the shutter during its movement between opened and closed positions. Said guide comprises two parallel support surfaces between which the shutter is slidably mounted. The distance between said support surfaces is greater than the thickness of the shutter adjacent said support surfaces so that the shutter is displaceable towards and away from said support surfaces in a direction perpendicular to said support surfaces.

Abstract: A drilling machine including a rock drill comprising a striking piston fitted to reciprocate in a cylinder. The piston is driven by a pressure medium. A rotation motor is provided and is driven by a pressure medium. A pump piston is permanently connected to a striking piston in concentric relation and arranged to travel in a pump cylinder. The cylinder is concentric with the cylinder that operates the striking piston and is axially spaced therefrom. The pump piston is arranged to provide a pump pressure medium to the rotation motor.

Abstract: A method of grinding wood under pressurized conditions in a grinder according to which wood is fed in batches into a pressurized gas-filled grinding chamber provided with a rotary grinding means. The wood batches are fed through a feeding chamber provided with means for sequentially opening and pressure-tightly closing said feeding chamber from two sides in and respectively out of communication with the atmosphere and said grinding chamber respectively. The groundwood stock is discharged from the grinding chamber through a pressure lock formed by the groundwood stock. In this way feeding of the wood batches into the grinding chamber and the discharging of the groundwood stock out from said grinding chamber are carried out as sluicing steps, whereby a continuous pressure can be maintained in the grinding chamber in spite of feeding of new wood batches and discharging of groundwood stock.

Abstract: A method of discharging groundwood stock when grinding wood under pressurized conditions in a grinding chamber, according to which the groundwood is suspended into stock and collected in a tank provided with an outflow for groundwood stock to atmospheric pressure. The surface of the stock in said tank is maintained at such a level above said outflow, that the stock in said tank forms a pressure lock in the communication between the grinding chamber and said outflow. In this way the discharging of the groundwood stock out from said grinding chamber is carried out as a sluicing step, whereby a continuous pressure can be maintained in the grinding chamber in spite of discharging of groundwood stock.

Abstract: A classifying apparatus for a suspension, especially for a pulp suspension, having a screen drum, means for feeding the suspension to one side of the screen drum, for removing thickened suspension from the same side of the screen drum and liquid from the opposite side of the screen drum, blades inclined in relation to their direction of rotation so that any one of the ends of the inclined blades is substantially on the same screen drum line parallel to the screen drum axis as the opposite end of some other blade and fitted to sweep at least one surface of the screen drum, and driving means for moving the blades in relation to the screen drum.

Abstract: A device for recovering chemicals from flue gases and green liquor obtained from burning the waste liquor of sodium based pulping processes, which device comprises a precarbonation reactor, a H.sub.