Abstract: The present invention relates to a degassing centrifugal apparatus (10), such as a degassing centrifugal pump (10) for use in a pulp- or papermaking process. The degassing centrifugal apparatus (10) according to the present invention comprises a rotatable hollow rotor (20) connected to a stationary fluid inlet (14) at one end portion and a stationary liquid outlet (18) at the opposite end portion, and having a gas exhaust (36) for removing gas from the centre thereof. The apparatus further comprises at said inlet end portion means (24) for rotating said fluid and directing it to the inner wall of said rotor (20). The apparatus further comprises a rotatable sensor (42) arranged to measure the layer thickness of a liquid (40) rotating in said apparatus.

Abstract: The present invention relates to a method for improving the efficiency of gas removal wherein gas-enriched process liquid (2) is introduced tangentially into a vertical essentially cylindrical vessel (1) and thereafter removed at the bottom of the vessel. By means of centrifugal force gas (2d) is brought to enrich in a part (2a, 2b) of the liquid (2). This part (2a) of liquid (2) having an enriched gas content (2c) is redirected to at least one vertical means (7) arranged centrally in the vessel (1), and separately removed therefrom. The present invention also relates to a de-gassing arrangement in an arrangement including at least one vertical essentially cylindrical vessel (1). Said vessel (1) includes at least one tangentially arranged inlet (4) for gas-enriched liquid and at least one discharge (6) for de-gassed liquid, which discharge is arranged at the lower portion of the vessel (1).

Abstract: The invention relates to a separation pump (1) for pumping a fluid mixture (2) of gas (3) and liquid or suspension (4) and for separating gas (3) and liquid or suspension (4) from each other. The separation pump (1) comprising a rotatable drum means (10) for rotating fluid mixture (2). The rotatable drum means (10) having an inner wall (11) and an inner space (12). The rotatable drum means (10) being rotatable for causing liquid or suspension (4) of fluid mixture (2) to form a layer of liquid or suspension (4) on the inner wall (11) and for causing gas (3) of the fluid mixture (2) to migrate towards the axis of rotation (13). The separation pump comprises foam discharging means (15) for discharging foam (16) from the inner space (12) of the rotatable drum means (10). The foam discharging means (15) comprises a second outlet (17).

Abstract: The invention relates to an arrangement for gas removal including a vertical cylindrical vessel (1) having an outlet (8) and a tangentially arranged inlet (6). The inlet includes means which bring an incoming fluid (4) into a jet which is sharply delimited in the radial direction and runs close to the vessel's (1) inner surface (5) at such a high initial velocity that an upwards open whirlpool (12) comprising a curved fluid surface (11) is formed. The outlet (8) is arranged tangentially at a level which is below the fluid surface (11). The invention also relates to a method for degassing a process fluid, wherein a deep whirlpool (12) including a curved fluid surface (11) is formed in a cylindrical vessel. At said fluid surface gas is brought to escape by means of centrifugal forces acting within the fluid. The invention further relates to the use of the above arrangement and method, respectively, for deaerating a process fluid in paper- or cellulose making.

Abstract: The present invention relates to a degassing centrifugal apparatus (10), such as a degassing centrifugal pump (10) for use in a pulp- or papermaking process. The degassing centrifugal apparatus (10) according to the present invention comprises a rotatable hollow rotor (20) connected to a stationary fluid inlet (14) at one end portion and a stationary liquid outlet (18) at the opposite end portion, and having a gas exhaust (36) for removing gas from the centre thereof. The apparatus further comprises at said inlet end portion means (24) for rotating said fluid and directing it to the inner wall of said rotor (20). The apparatus further comprises a rotatable sensor (42) arranged to measure the layer thickness of a liquid (40) rotating in said apparatus.

Abstract: The invention relates to an arrangement for gas removal including a vertical cylindrical vessel (1) having an outlet (8) and a tangentially arranged inlet (6). The inlet includes means which bring an incoming fluid (4) into a jet which is sharply delimited in the radial direction and runs close to the vessel's (1) inner surface (5) at such a high initial velocity that an upwards open whirlpool (12) comprising a curved fluid surface (11) is formed. The outlet (8) is arranged tangentially at a level which is below the fluid surface (11). The invention also relates to a method for degassing a process fluid, wherein a deep whirlpool (12) including a curved fluid surface (11) is formed in a cylindrical vessel. At said fluid surface gas is brought to escape by means of centrifugal forces acting within the fluid. The invention further relates to the use of the above arrangement and method, respectively, for deaerating a process fluid in paper- or cellulose making.

Abstract: In a process and an arrangement for directing a papermaking pulp towards a regulated outlet (9), accept from successive cleaning stages (6, 14, 20) is totally or partly led towards the outlet (9) while excess accept is led in the opposite direction to the inlet (5) of the preceding cleaning stage (6). For feeding of a forming wire, a common base pipe (8) for collecting accept extends between the outlet (9) and a feeding (3) for fresh pulp, while reject pipes (11, 18) lead to the next cleaning stage (14, 20).

Abstract: Apparatus and method are provided for treating a fluid mass or stock, particularly couch stock in paper making. Stock material is fed into a vessel having a mixing arrangement comprising rotatably arranged processing means. At lest two processing means are caused to rotate mutually adjacent in opposite direction and essentially horizontally. The stock at the upper surface of the means is conveyed towards a wall portion of the vessel, whereby spirals arranged in an inclined manner at a core of the processing means bring stock into channels defined by the core, by the spirals, and by the wall portion of the vessel, and further towards a constriction formed by the respective spiral elements running in an intermeshed manner, while a part of the stock is forced in a direction away from a discharge of the vessel.

Abstract: The invention relates to a degassing centrifugal apparatus such as a pump and to a process for pumping and degassing a fluid. The apparatus has a rotatable hollow rotor connected to a stationary fluid inlet at one end and a stationary liquid outlet at the opposite end and a gas exhaust in the center thereof. The rotor has at its inlet end a bladed wheel with arcuate blades. The bladed wheel accelerates a fluid flow in said rotor inlet end and causes the fluid to rotate at a peripherical velocity higher than the peripherical velocity of said rotor inlet end. The apparatus is especially useful for pumping and degassing backwater in the production of paper or board in a paper machine.

Abstract: The invention relates to a process for collecting process water at a paper machine or the like, wherein water from several suction elements (2 . . . 2n, 2m) provided at a wire (1) is led in such a way that an unbroken liquid column is maintained in the outlet pipes (8 . . . 8n, 8m) of the suction elements and is made to join a common collecting vessel (9, 9m). The liquid levels (20 . . . 20n) of the outlet pipes am regulated by regulating the liquid level (11) in at least one separate level vessel (10) towards which the water from the respective outlet pipes is led in at least one closed and essentially horizontal collecting channel (9, 9m) which is common for several outlet pipes. (8 . . . 8n, 8m), the liquid in said collecting channel (9, 9m) at the same time forming the lower part of said unbroken liquid column.

Abstract: Apparatus and method are provided for treating a fluid mass or stock, particularly couch stock in paper making. Stock material is fed into a vessel having a mixing arrangement comprising rotatably arranged processing means. At lest two processing means are caused to rotate mutually adjacent in opposite direction and essentially horizontally. The stock at the upper surface of the means is conveyed towards a wall portion of the vessel, whereby spirals arranged in an inclined manner at a core of the processing means bring stock into channels defined by the core, by the spirals, and by the wall portion of the vessel, and further towards a constriction formed by the respective spiral elements running in an intermeshed manner, while a part of the stock is forced in a direction away from a discharge of the vessel.

Abstract: Method and apparatus for treating a fluid mass or stock, particularly couch stock or the like in paper making. Stock material is fed to a vessel having a mixing arrangement comprising rotatably arranged processing means. At least two processing means are caused to rotate mutually adjacent in opposite directions and substantially horizontally. The stock at the upper surface of the means is conveyed towards a wall potion of the vessel, whereby spirals arranged in an inclined manner at a core of the processing means bring the stock into channels defined by the core, by the spirals, and by the wall portion of the vessel, and further towards a constriction formed by the spiral elements running in an intermeshed manner, while a part of the stock is forced in a direction away from a discharge of the vessel.

Abstract: The invention relates to an apparatus and a process for feeding papermaking stock to a papermachine. The apparatus comprises a mixing vessel (12) for receiving and mixing stock components and a pipe (40) for feeding the resulting mixed stock to said papermachine. In the feeding pipe (40) there are stock flow metering means (42) stock consistency sensing means (44) and stock flow control means (32). Said means are all connected to a control system (46) adapted for receiving said flow data (Q) and said consistency data (C). The control system (46) is adapted for continuously computing a value for the product (Q×C) of said flow and consistency and for providing adjustment of the flow control means (32) to keep said product (Q×C) at a target value. The invention provides faster response times in the control of a papermaking process. It also reduces the volume of stock mixing vessels and the amount of water in the process.

Abstract: The present invention relates to an apparatus and a process for screening a fibre suspension such as papermaking stock in a pressurized screen especially in connection with pumping the liquid. The invention also relates to the use of the apparatus in a process for the production of paper or board. The apparatus comprises a generally tubular housing (12) and a perforated screen-drum (22) inside the housing. The housing (12) and screen-drum (22) define between themselves a generally annular screening zone (30). The screen-drum (22) surrounds a tubular accept channel (32). The apparatus further comprises a stock inlet (14), outlet (19) for accept, and outlet (17) for reject. The screen-drum (22) is rotatable within the housing (12) and conducts are provided for introducing diluting fluid into the annular screening zone (30) at a plurality of locations along its axial extent.

Abstract: A process and apparatus for pumping a fluid mixture of a gas and a liquid and for separating said gas and liquid from each other, said apparatus having a fluid inlet (14) at one end (18) and at the opposite end (22) a pump housing (16) with a liquid outlet (28) and, between said inlet (14) and said pump housing (16), a hollow elongated gas separation part (30) of an essentially circular cross section with a generally central outlet (26) for separated gas. Said gas separation part (30) is provided by a hollow rotor (12) between said inlet (14) and said pump housing (16), the inner wall of said rotor (12) providing a large rotatable gas separation surface (32). The diameter of said rotor (12) increases at said opposite end (22) of the apparatus to form a larger diameter pumping zone (17) extending into said pump housing (16). Said rotor (12) is provided with a blade wheel (24) extending into said pump housing (16).

Abstract: The invention relates to a process and an apparatus for recycling backwater in a papermaking machine. According to the invention backwater draining through a forming fabric is collected into several collecting means (51, 52, 53, 54) and pumped by separate pumps (20) in at least two and preferably numerous separate flows (81 to 85) directly as substantially air free separate flows to the fibre process (12, 30, 40) of the short circulation in order to implement a fast, air free and split recycling of backwater from said forming fabric to said fibre process.