# US 2013/0156545 A1 · Dual-flow centrifugal pump > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2013/0156545 A1 - Document ID: US20130156545A1 - Status: Published application - Kind: A1 - Application number: 13/704,080 - Filed: 2011-05-09 - Published: 2013-06-20 - Earliest claimed: 2010-06-16 - Assignees: Allweiler AG - Inventors: Manfred Britsch - Web page: https://patentgrep.com/patent/US20130156545A1 ## CPC - F04D 1/00: Radial-flow pumps, e.g. centrifugal pumps; Helico-centrifugal pumps (adapted for pumping specific fluids F04D7/00; priming or boosting F04D9/00) - F04D 1/006: {double suction pumps} - F04D 29/167: {of a centrifugal flow wheel} - F04D: NON-POSITIVE-DISPLACEMENT PUMPS (engine fuel-injection pumps F02M; ion pumps H01J41/12; electrodynamic pumps H02K44/02) ## Abstract A double-flow centrifugal pump is disclosed, in which, using an impeller, a fluid can be suctioned from two axial sides from a negative pressure area and can be delivered in the radial direction into a positive pressure area. The negative pressure area is sealed off with respect to the positive pressure area by at least one stationary pump component, for example the pump housing and/or an insert part. According to the invention, sealing gaps are formed as axial gaps arranged axially between the impeller and the pump component and extending in the circumferential direction and in the radial direction, wherein the gap width(s) of said axial gaps is less than the radial spacing (a) of the impeller from all the components arranged with a radial spacing from the impeller. ## Claims ### Claim 1 A double-flow centrifugal pump for delivering a flow rate in a range from 500 m3/h to 4000 m3/h, the pump positioned in a vertical orientation, and having a pump housing and a dual-flow impeller rotationally fixedly arranged on a rotationally driven shaft, with which impeller a fluid can be suctioned drawn from two axial sides from a negative pressure area and delivered in the radial direction into a positive pressure area, wherein the negative pressure area is sealed off with respect to the positive pressure area by at least two axially spaced sealing gaps formed between the impeller and at least one stationary pump component, the at least one stationary pump component comprising at least one of the pump housing and a stationary insert, and wherein the shaft is mounted only on one side, and the sealing gaps comprise as axial gaps extending in the circumferential direction as well as in the radial direction and arranged axially between the impeller and the at least one stationary pump component, the gap width of which is less than the radial distance of the impeller to all components that are arranged at a radial distance to the impeller. ### Claim 2 (depends on 1) The centrifugal pump according to claim 1, wherein the gap width of the sealing gap is between 200 μm and 2000 μm. ### Claim 3 (depends on 1) The centrifugal pump according to claim 1, wherein the radial distance of the impeller to the at least one stationary pump component of the centrifugal pump with the impeller standing still is between 2 mm to 10 mm. ### Claim 4 (depends on 1) The centrifugal pump according to claim 1, wherein the sealing gaps are arranged between the front sides of the impeller and between the pump housing or the stationary insert. ### Claim 5 (depends on 1) The centrifugal pump according to claim 1, wherein the sealing gaps run exactly in the radial direction. ### Claim 6 (canceled) ### Claim 7 (depends on 1) The centrifugal pump according to claim 1, wherein the centrifugal pump is configured to deliver a volume flow in a range between approximately 800 m3/h and approximately 1500 m3/h. ### Claim 8 (canceled) ### Claim 9 (depends on 1) The centrifugal pump according to claim 1, wherein the two sealing gaps have a smaller radial distance from the shaft than radial gaps between the impeller and the at least one stationary pump component. ### Claim 10 (depends on 1) The centrifugal pump according to claim 1, wherein the impeller has a circular, cylindrical casing contour. ### Claim 11 (depends on 1) The centrifugal pump according to claim 1, wherein the centrifugal pump is configured to deliver a volume flow in a range between about 1500 m3/h and about 2300 m3/h at a maximum delivery level. ### Claim 12 (depends on 1) The centrifugal pump according to claim 1, wherein the centrifugal pump is configured to deliver a volume flow in a range between approximately 2300 m3/h and 3500 m3/h at a maximum delivery level. ### Claim 13 (depends on 1) The centrifugal pump according to claim 1, wherein the centrifugal pump is configured to deliver said volume flow at a maximum delivery level in a range between about 20 m and about 50 m. ### Claim 14 (depends on 13) The centrifugal pump according to claim 13, wherein the maximum delivery level is approximately 30 m. ### Claim 15 (depends on 1) The centrifugal pump according to claim 1, wherein the sealing gaps include a radial plane an angle of approximately 0° and 1°. ### Claim 16 (depends on 1) The centrifugal pump according to claim 1, wherein the sealing gaps have a radius of curvature of about 200 mm to 1000 mm. ### Claim 17 (depends on 1) The centrifugal pump according to claim 1, wherein the sealing gaps have a radius of curvature of about 300 mm to 700 mm.