CONDITION MONITORING OF PUMPS AND PUMP SYSTEM
(19)AUSTRALIAN PATENT OFFICE (54) Title CONDITION MONITORING OF PUMPS AND PUMP SYS I bM (51)6 International Patent Classification(s) F04D 015/00 F04B osi/oo (21) Application No: 2003254479(22) Application Date: 2003.07.21 (87) WIPONo: WO04/011810 (30) Priority Data (31) Number (32) Date 0217494.4 2002.07.29(33) Country GB (43) Publication Date : 2004.02.16 (43) Publication Journal Date : 2004.03.25 (71) Applicant(s) THE BOC GROUP PLC (72) Inventor(s) SCHOFIELD, Nigel, Paul; ABBASZADEH Siamak; SAVIDGE, Derek (H) Application NoAU2003254479 A1(19)AUSTRALIAN PATENT OFFICE (54) Title CONDITION MONITORING OF PUMPS AND PUMP SYS I bM (51)6 International Patent Classification(s) F04D 015/00 F04B osi/oo (21) Application No: 2003254479(22) Application Date: 2003.07.21 (87) WIPONo: WO04/011810 (30) Priority Data (31) Number (32) Date 0217494.4 2002.07.29(33) Country GB (43) Publication Date : 2004.02.16 (43) Publication Journal Date : 2004.03.25 (71) Applicant(s) THE BOC GROUP PLC (72) Inventor(s) SCHOFIELD, Nigel, Paul; ABBASZADEH Siamak; SAVIDGE, Derek A method of monitoring the condition of a pump (10) or at least one component of a system that includes a pump which component or components are not a part of the pump, includes the step of generating a predetermined test condition in the pump or system component or components. During a period in which such a test condition is present, signals indicative of the pump or system component or components are obtained. Wear in the pump bearings, the build-up of deposits in the pump or in pipework forming a part of the pump system can be detected or predicted and corrective action taken before the pump or system fails. By providing a method of monitoring pump or system condition in-situ, it is possible to reduce the likelihood of pump failure in use and the need to carry out over frequent servicing of the pump. A method of monitoring the condition of a pump, the method comprising the steps of generating a predetermined test condition in said pump and obtaining signals indicative of a condition of said pump during a period in which said test condition is present, characterised in that said step of generating a predetermined test condition comprises causing a reduction in clearance between parts of the pump and said signals are obtained during a period in which said reduction in clearance is present. A method as claimed in claim 1, wherein said step of generating a predetermined test condition comprises generating an abnormal load condition whereby said pump is subject to an increased stress as compared with normal operating stresses. A method as claimed in claim 2, wherein said pump has a rotor and a stator and the clearance that is reduced is a clearance between the rotor and the stator. A method as claimed in claim 3, wherein said clearance is reduced at least in part by selective control of rotational speed of said rotor. A method as claimed in claim 4, wherein said reduction in clearance is at least in part caused by the steps of causing a predetermined reduction in rotor rotation speed from a selected speed for a predetermined period of time and then causing a predetermined increase in rotor rotation speed above said selected speed for a predetermined period of time. A method as claimed in any preceding claim, wherein said pump is provided with a cooling system and said reduction in clearance is at least in part caused by controlling a rate of flow of coolant to cause a perturbation of temperature in said pump. A method as claimed in any preceding claim, wherein said reduction in clearance is at least in part caused by increasing a gas flow rate through said pump. A method as claimed in any one of the preceding claims, wherein said pump is driven by an electric motor and said signals provide an indication of the current supplied to said motor. A method as claimed in any one of the preceding claims, wherein the pump or apparatus with which the pump is associated is equipped to store said signals A method as claimed in any one of the preceding claims, wherein said signals are transmitted to a storage location via a LAN or the internet. A method as claimed in any one of the preceding claims, wherein said signals are analysed to assess the condition of the pump. A method as claimed in claim 11, wherein said analysing step comprises comparing said signals with signals obtained during at least one previous predetermined test condition of the pump. A method as claimed in claim 11 or 12, wherein said analysing step comprises comparing said signals with pre-programmed data. A method as claimed in claim 11, 12 or 13 wherein said analysing step comprises comparing said signals with signals obtained from at least one other pump of another system during at least one predetermined test condition of the or each other pump. A method as claimed in claim any one of claims 11 to 14, wherein said analysing step comprises inputting said signals into an algorithm to provide a prediction of pump condition. A method as claimed in any one of claims 11 to 15, wherein said analysing step comprises inputting said signals into an algorithm to provide a prediction of pump life until a predetermined condition of the pump will occur. A method as claimed in any one of claims 11 to 16, wherein signals indicative of a system component condition are obtained and said analysing step includes using said signals to predict a condition of the pump or system. A method as claimed in any one of claims 11 to 17, further comprising providing an audible indication of the result of said analysing step. A method as claimed in any one of claims 11 to 18, further comprising providing a visual indication of the result of said analysing step. A method as claimed in any one of claims 11 to 19, wherein said pump is automatically closed down if said analysing step indicates a predetermined condition of the pump. A method as claimed in any one of the preceding claims, wherein the pump or apparatus with which the pump is associated is able to determine whether the pump is in a condition that permits testing of the pump and to cause the implementation of the steps of any one of the preceding claims if said condition permits testing of the pump condition. A method as claimed in claim 21, wherein said determining step is performed at predetermined intervals. Apparatus comprising a pump, pump controller and at least one sensing device for sensing a pump operating parameter, said pump controller being able to control said pump so as to selectively generate a predetermined pump test condition and the or each said sensing device providing signals indicating values of said parameter when said test condition is generated, characterised in that the pump controller is configured to selectively generate the pump test condition by causing a reduction in clearance in parts of the pump and that said sensing device is configured to provide said signals during the reduction in said clearance. Apparatus as claimed in claim 23, wherein said at least one sensing device comprises a current sensing device for sensing current supplied to a motor that drives said pump. Apparatus as claimed in claim 23 or 24, wherein said at least one sensing device comprises a pressure sensing device for sensing a pressure in said apparatus. Apparatus as claimed in claim 23, 24 or 25, wherein said apparatus comprises a cooling system for said pump, said controller being operable to control said cooling system to generate a said predetermined test condition. Apparatus as claimed in any one of claims 23 to 26, wherein said controller is able to control pump speed to generate a said predetermined test condition. Apparatus as claimed in any one of claims 23 to 27, wherein said apparatus comprises a source of pressurised gas and said controller is able to cause a flow of gas from said source to generate a said predetermined test condition. Apparatus as claimed in any one of claims 23 to 28, wherein said controller comprises a computer connectable with said pump. Apparatus as claimed in claim 29, wherein said controller is connectable with the pump via a LAN or the internet.