Method and apparatus for pumping a material and a rotor for use in connection therewith
AssigneeSulzer Pumpen AG
InventorsKari Peltonen, Reijo Vesala, Vesa Vikman
Life of this patent
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Abstract
A method and apparatus is disclosed for pumping a material, especially thick, gas-containing, fiber suspensions for wood processing. The apparatus includes a centrifugal pump with a rotor having blades twisted such that the pitch of the blade changes along the length of the rotor.
Claims37
A method of pumping a gas-containing and viscous material with a pumping apparatus comprising a casing, suction and discharge ducts therein, an impeller further comprising at least one or more pumping vanes, and a rotor arranged in front of the impeller, which rotor further comprises one or more blades each having an increasing pitch in a direction towards the impeller, wherein said method comprises:
- introducing material to flow to the pumping apparatus through said suction duct;
- rotating the one or more blades of the rotor to move the material through the suction duct and to the impeller, and
- discharging the material from said pumping apparatus to the discharge duct;
- wherein the increasing pitch of the one or more blades of the rotor increases a pressure of the material as the material is moved by the blades towards the impeller, and at a final part of the suction duct adjacent the impeller the rotor subjects the material to centrifugal force in order to separate gas from the material.
An apparatus for pumping a gas-containing and viscous material comprising:
- a casing housing a suction duct, a discharge duct, an impeller comprising at least one or more pumping vanes, and a rotatable rotor arranged in front of and immediately upstream of the impeller, which rotor further comprises one or more blades wherein each blade is twisted so that a pitch of the blade changes along a length of the rotor,
- wherein said apparatus further comprises a gas-separation zone proximate to the impeller, and said pitch of the blades of the rotor is increased towards said gas-separation zone such that in said zone the blades subject the material to centrifugal force for separating gas from the material.
An apparatus for pumping a gas-containing and viscous material comprising a casing, suction and discharge ducts therein, an impeller comprising at least one or more pumping vanes, and a rotatable rotor arranged in front and immediately upstream of the impeller,
- which rotor further comprises one or more blades and each of said blades having a pitch increasing along the length of the rotor, and
- said apparatus further comprising, in the vicinity of the impeller, a gas-separation zone, wherein said pitch of said one or more blades of the rotor increases towards the impeller.
An apparatus for pumping a gas-containing and viscous material comprising a casing, suction and discharge ducts therein, an impeller comprising at least one or more pumping vanes, and a rotatable rotor arranged in front of and immediately upstream of the impeller, which rotor further comprises one or more blades each being twisted so that a blade pitch changes along a length of the rotor, and
- said apparatus further comprising, in the vicinity of the impeller a gas-separation zone, in which said pitch of said one or more blades of the rotor alters to at least five-fold.
An apparatus for pumping a gas-containing and viscous material comprising a casing, suction and discharge ducts therein, an impeller comprising at least one or more pumping vanes, and a rotatable rotor arranged in front of the impeller,
- said rotor further comprises one or more blades twisted so that a pitch of each blade changes along a length of the rotor, and said apparatus further comprising, in the vicinity of the impeller, a gas-separation zone in which said pitch of said one or more blades of the rotor alters at least ten-fold.
A rotatable rotor for use an apparatus comprising a casing, suction and discharge ducts therein and an impeller having at least one or more pumping vanes for pumping a viscous and gas-containing material, said rotor comprising:
- a tip portion at an end of the rotor and an other end of the rotor facing and adjacent the impeller, said rotor further comprising one or more blades twisted so that a pitch of each blade varies along a length of the rotor, wherein said pitch of said one or more blades of the rotor is increased from said tip portion of the rotor towards said other end of the rotor to form a gas separation zone along the rotor.
A rotatable rotor in an apparatus comprising a casing, suction and discharge ducts therein, and an impeller having at least one or more pumping vanes for pumping a viscous and gas-containing material, said rotor further comprising
- one or more blades twisted so that a pitch of each blade varies along a length of the rotor, said pitch being greatest at an end of the rotor adjacent the impeller, wherein the pitch of the one or more blades of the rotor alters at least five-fold.
A rotatable rotor in an apparatus comprising a casing, suction and discharge ducts therein, and an impeller having at least one or more pumping vanes for pumping a viscous and gas-containing material, said rotor further comprises one or more blades being twisted so that a pitch of each blade varies along a length of the rotor, said pitch of the blades of the rotor being greatest at an end of the rotor adjacent the impeller, and said blades with varying pitch forming a gas-separation zone in the rotor and said rotor further comprising gas-removal openings.
A method of pumping a gas-containing and viscous material with a pumping apparatus comprising a casing having a suction duct and a discharge duct, an impeller, and a rotor arranged in the suction duct upstream of the impeller, wherein the rotor has at least one helical blade having a pitch which increases along an axis of rotor and in a direction towards the impeller, wherein the method comprises:
- introducing the material into a front portion of the rotor;
- rotating the at least one blade of the rotor to move the material through the rotor, suction duct, and to an inlet of the impeller;
- suppressing vaporization of the material in the front portion of the rotor due to a shallow blade pitch and the rotation of the rotor which at least maintains a pressure of the material in the front portion of the rotor;
- separating gases from the material in a rear portion of the rotor by increasing the blade pitch in the rear portion and applying centrifugal forces to the material by the rotation of the rotor;
- directing the material in the rear portion of the rotor to the impeller;
- allowing the separated gases in the material to vent out of the material, and
- discharging the solids in the material from the impeller through the discharge duct.
A gas separator for a viscous material comprising:
- a casing housing an impeller;
- a rotatable rotor having a discharge adjacent the impeller and an inlet adapted to receive the viscous material;
- at least one blade on the rotor having a blade pitch defined by an angle between a surface of the blade and a plane perpendicular to a rotor axis, wherein the blade pitch increases along a length of the rotor and in a direction towards the rotor discharge;
- a suction duct housing a rear portion of the rotor and attached to the casing, wherein said suction duct and rotor define a vapor separation region, and
- a front portion of the at least one blade having a shallow blade pitch to suppress vaporization of the fluid in the front portion.
Dependencies are inferred from the claim text.