US 12,140,142 B2
Rotary positive displacement pump
Simon Cargill, Eastbourne (GB)
Assigned to ALFA LAVAL CORPORATE AB, Lund (SE)
Appl. No. 18/260,531
Filed by ALFA LAVAL CORPORATE AB, Lund (SE)
PCT Filed Jan. 19, 2022, PCT No. PCT/EP2022/051070
§ 371(c)(1), (2) Date Jul. 6, 2023,
PCT Pub. No. WO2022/157167, PCT Pub. Date Jul. 28, 2022.
Claims priority of application No. 21152412 (EP), filed on Jan. 19, 2021.
Prior Publication US 2024/0052834 A1, Feb. 15, 2024
Int. Cl. F04C 2/12 (2006.01); F04C 11/00 (2006.01); F04C 13/00 (2006.01); F04C 15/00 (2006.01)
CPC F04C 15/0096 (2013.01) [F04C 2/126 (2013.01); F04C 11/001 (2013.01); F04C 13/002 (2013.01); F04C 2230/60 (2013.01); F04C 2230/604 (2013.01); F04C 2230/70 (2013.01); F04C 2240/30 (2013.01)] 26 Claims
OG exemplary drawing
 
1. A rotary positive displacement pump for pumping a fluid product, the pump having a front side and a rear side and comprising:
a transmission housing providing rotational support to first and second parallel and axially extending drive shafts having gears in constant mesh condition, such that the first and second drive shafts are arranged to rotate in opposite directions,
a rotor casing connected to a front side of the transmission housing and having an axial rear wall, an axial front wall and a circumferential side wall jointly defining a stationary interior pumping cavity,
wherein the rotor casing houses a first rotor that is drivingly connected to the first drive shaft and a second rotor that is drivingly connected to the second drive shaft,
wherein the first and second rotors are configured for rotating in opposite directions and mutually interacting for providing a positive pumping effect on the fluid product that enters the pumping cavity via a rotor casing inlet and exits the pumping cavity via a rotor casing outlet,
wherein the rotor casing further includes first and second sealing arrangements configured for preventing the fluid product from leaking out from the stationary pumping cavity towards the rear side of the rotor casing along the first and second drive shafts, respectively,
wherein the pump further comprises a heating device configured for heating the rotor casing, the first and second sealing arrangements and/or any fluid product within the rotor casing, the heating device being separate from both the transmission housing and the rotor casing, the heating device being detachably fastened to the axial rear wall of the rotor casing so that the heating device is separable from the rotor casing.
 
19. A method for heating a rotor casing and/or a fluid product within the rotor casing of a rotary positive displacement pump having a front side and a rear side, wherein the rotary positive displacement pump comprises a transmission housing and the rotor casing, wherein the transmission housing gives rotational support to first and second parallel and axially extending drive shafts having gears in constant mesh condition, such that the first and second drive shafts are arranged to rotate in opposite directions, wherein the rotor casing is connected to a front side of the transmission housing and having an axial rear wall, an axial front wall and a circumferential side wall jointly defining a stationary interior pumping cavity, wherein the rotor casing houses a first rotor that is drivingly connected to the first drive shaft and a second rotor that is drivingly connected to the second drive shaft, wherein the first and second rotors are configured for rotating in opposite directions and mutually interacting for providing a positive pumping effect on a fluid product that enters the pumping cavity via a rotor casing inlet and exits the pumping cavity via a rotor casing outlet, wherein the rotor casing further includes first and second sealing arrangements configured for preventing fluid product from leaking out from the stationary pumping cavity towards the rear side of the rotor casing along the first and second shafts, respectively, the method comprising:
detachably fastening a heating device to the axial rear wall of the rotor casing, the heating device being separate from both the transmission housing and the rotor casing, the heating device being detachably fastened to the axial rear wall of the rotor casing so that the heating device is separable from the rotor casing, and
activating the heating device for heating the rotor casing, the first and second sealing arrangements and/or any fluid product within the rotor casing.