GB2430034A - A condition monitoring device using acoustic emission sensors and data storage devices. - Google Patents

Abstract

A condition monitoring system, using at least one acoustic emission sensory device to indirectly and/or remotely monitor the health status of a piece of rotating equipment, and applications thereof as for example a mechanical seal or a bearing assembly. The acoustic emission sensory device can be placed in direct or indirect contact to counter rotating surfaces. The signal emitted by the acoustic emission sensory device can be amplified, filtered for background noise, computed, compared to reference values and stored on a data storage device.

Description

II

Acoustic Emission Condjtjn Monitoring System for Rotating guipment and ApDlicatlons of usettiereof

Technial Field

The present invention relates to items of rotating equipment, specifically members within in such equipment, which either interact between the rotating and stationary members and/or form or are adjacent to the counter sliding surface. By way of example only, said stationary and rotary interacting members may be roller / ball bearings or one or more seal faces in a mechanical seal assembly.

Background

Rotating equipment containing said counter sliding members, are common in virtually all types of industries. The counter sliding parts generally operate in a fluid film regime. Said fluid film is often a liquid or gas which can act as a cooling agent, and/or load carrying agent to help reduce heat build up and/or rotating equipment energy consumption, for example.

There is considerable text, on the various fluid film regimes theorised between the counter sliding members. A. Lebeck in the Principles and Design of Mechanical Face Seals, 1901, is one such author outlining the theories.

Said fluid film regimes are often defined by staged conditions Each stage defines the typical condition of the sliding surfaces and resulting properties thereof. Lebeck, for example, defines the three stages; Full film Lubrication, Mixed Lubrication and Boundary Lubrication. Other authors refer to these three stages as wet or thick, normal and dry or thin respectively.

Should the fluid film thickness and/or physical properties of the fluid film change, the counter rotaUng members may move away from their optimised running condition, hence move into a different fluid film lubrication stage An example of such a change in lubrication regime is the addition of water molecules into an oil lubricated bearing assembly. A further example is mechanical seal face rotation/distortion due to external influences such as pressure or temperature.

Condition monitoring is the science of detecting changes, in, for example, rotating equipment, before equipment seizure andlor shutdown occurs. Detecting fluid film changes, between counter rotating parts, is considered by most, as the most accurate and technicalry appropriate condition monitoring approach for rotating equipment. Until recently it has been considered to be extremely thfficult to determine what exactly is happening at the fluid film interface between two or more counter sliding/rotating surfaces.

The Acoustic Emission (AE) method has been investigated for its use in condition monitoring. AE relies on the emission of ultrasonic acoustic waves by a pair of surfaces when they are in sliding contact.

Until recently there have been many problems associated with using AE techniques to condition monitor equipment. These issues are outlined by Jarzyriski et al, US 6,36061O, and thus have prevented it's use.

Jarzynski US 6,360,610 attempts to overcome said issues by introducing a wave source directed at the counter rotating mechanical seal faces, He then monitors the returned wave, noting and relating the wave changes (input-output) to predetermined wave characteristics.

This dosed loop system involves input and output waves. Not only can the quality of the transmitted and return signals be effected by a Copyilghl 2005 AESSFAL plo, A.Roddis 03.05.05 number of operating vanables such as equipment vibration, and/or shaft speed, and/or temperature. Therefore the temperature and speed are also monitored within this closed loop system. The physical technical and commercial logistics of incorporating wave transmitting and receiving sensors into mechanical seals requires a large space to attach all these sensors, in which it makes this approach unworkable for the vast majority of industrial applications, specially where the temperature and speed are riot stable.

The experienced reader will note that in the case of condition monitoring a pair of methanical seal faces, the seal faces are often installed inside a radial space envelope, between the stationary housing and rotating shaft, of 5/16" (8mm). If the sensor itself is 6mm or 8mm in diameter, the limitations of use of such a device is self- apparent.

The present invention and/or applications of the invention, is exemplified by the following text, which, by way of example only, is directed to its use in mechanical seals. However, the experienced reader will note the many other applications which technology can be applied to, including roller and ball bearing assemblies, as described later.

A Mechanical seal comprises a "floating" component which is mounted axially movably around the rotary shaft of, for example, a pump and a "statics component which is axially fixed, typically being secured to a housing. The floating component has a flat annular end face, i.e. its seal face, directed towards a complementary seal face of the static component. The floating component is urged towards the static component to close the seal faces together to form a sliding face seal, usually by means of one or more spring members. In use, one of the floating and static components rotates; this component is therefore referred to as the rotary component. The other of the floating and static components does not rotate and is referred to as the stationary component Those seals whose floating component is rotary are described as rotary seals If the floating component is stationary, the seal is referred to as a stationary seal, If the sliding seal between the Rotary and Stationary components are assembled and pre-set prior to despatch from the Mechanical seal manufacturing premises, the industry terminology for this is cartridge sear. If the Rotary and Stationary components are despatched individually (unassembled) from the Mechanical seal manufacturing premises, the industry terminology for this is "component seals Mechanical seals are used in all types of industries to seal a variety of different process media and operating conditions. The general industry term which defines the area adjacent to the process media is inboard. The industry term which defines the area adjacent to the atmospheric side is uoutboardH Condition Monitoring is one of the key elements, which differentiates companies competing in the same industrial sectors.

Companies, which embrace and develop products and technologies, that help them improve their service levels to their customers, are more likely to grow or survive in a highly competitive world.

Condition Monitoring is the ability to predict the performance of the supplied product, given a complex situation.

A complex situation is one where there are many variables that can effect the performance of a product.

Such variables may be predictable, or as often found, they are unpredictable. In the mechanical seal industry, such unpredictable variables or events include process pressure spikes, high/low thermal process excursions, equipment seizure or support service failure.

Such unpredictable variables suggest that a product, Which has the Intelligence to be able to detect and interact with data from a complex situation, will be of great value to a customer or user of that product.

Further advantages may be realised if the product is used in a complex and highly sensitive application. A sensitive application is defined as one which, product failure, must be avoided. An example of such a sensitive application is given as a mechanical seal used to seal a reactor of a nuclear process. If the mechanical seal unpredictably fails, the resulting loss of production or damage to the environment could be incalculable.

The Acoustic Emission (AE) is a method of measuring the behaviour of materials deforming under stress, or in simpler terms the energy of vibration of a counter rotating or sliding surfaces. AE may be defined as a transient elastic wave generated by the rapid release of energy within a material. AE relies on the emission of ultrasonic acoustic waves by a pair of surfaces when they are in sliding contact.

Under differing film fluid regimes in between two contacting surfaces like mechanical seal faces, where the aspirates between the sliding surfaces contact each others, it transmits a wave with high frequency in which can be identified from any other type of waves within the environment. It has been surprising discovered that such transmitted data is on a far greater magnitude compared to other sources of equipment vibration, herewith referred to as noise. This AE was only approved to work on metallic parts and many works are done on different material type, while this is the first time that it has been developed within this patent to be able to monitor the contact in between non-metallic parts like mechanical seal faces.

Tests show that the sliding surface vibration energy of the counter rotating surfaces within a mechanical seal is around 10 fold greater than other equipment noise. This makes it easy to determine the difference between the two. This high level frequency wave can be directly measured from the body of the part, however this wave can also travel within a surrounding liquid and other solid parts within a certain length, in which it is succeeded to be measured from the gland of a mechanical seal within this patent.

Once this data is collected, it can be offered to a user in a variety of ways, of which the background to three typically employed generic forms, by way of example only, are described below.

Wireless technology including, but not limited too; Internet, Satellite, WAP (wireless application protocol) phones, LAN (local area network), WLAN (wireless local area network), field bus connector, WEP (wireless encryption protocol) and Blue Tooth.

Clearly hard wire technology can also be employed. The experienced reader will understand that this technology also allows the health monitor software to dial and send a message to a mobile cell phone, if required.

- Radio Frequency Identification (RFID) is a system, which allows a user to review product information through a tag and scan" system. RFID technology is used in conjunction with a data storage unit, typically a RFID storage chip. Said data storage unit contains data, which may be of use to the user, Such data may include product expiry date and/or product serial number. it is considered self explanatory that the present invention may also be applied with RFDC (Radio Frequency Direct Communication) as well as any other similar type of read/write data storage technology.

- Visual recognition via an LED, monitor, alarm and/or light system Jn addition to these three generic post AE collated data techniques, the present invention anticipates an intelligent system where the collected AE data is uses to activate a rectification solution to re- establish an idealised or preferred fluid film condition.

For the purpose of this application, products with multiple configuration options are termed as complex assemblies.

Summary of the Invention

Rotating equipment includes pumps, mixers, reactors agitators, basically any item of equipment, which pumps or mixes a product media All items of rotating equipment have counter sliding surfaces, which typically operate on a fluid film.

Mechanical seals, are one such example of an item of rotating equipment containing one or more sliding surfaces which are employed to prevent the sealed media from escaping.

It is common knowledge that the condition of the fluid film, between two counter sliding surfaces, is an accurate and reliable source to predict the operating life, and/or heat generation etc. of said surfaces.

The condition of the fluid film is a variable, which can change over the life of the rotating equipment. For example, elevated temperature excursions can cause the fluid film to vaporise thus reducing its lubrication properties. Likewise, elevated pressure excursions can distort the seal faces, leading to dry runninq or contact at one or more points across the seal face.

Manual tracking of the possible process variables, using conventional measuring techniques at plant level, for each mechanical seal is often an impossible task. This task is further complicated if the variables are constantly changing, and/or in the mechanical seal and/or support system variables are included in the calculation.

AdvantaQ of the Present Invention A condition monitoring system, which can detect changes in the fluid film regime of a counter sliding surface without having to transmit a signal directed at said counter sliding surface.

Said fluid film sensor(s) do not need to be physically positioned adjacent to the counter rotating surface, thus the application of the invention is not limited by the physical space limitations of the equipment.

A user can remotely monitor one or more counter sliding surfaces of the rotating equipment, remotely at plant level, preferably from a central position or alternatively using a remote or direct data gathering system.

The invention is described with the aid of the following drawings.

Figure 1, illustrates a typical rotating equipment assembly, such as a centrifugal pump, fitted with a single rotary cartridge mechanical seal of the invention.

Figure 2A corresponds to Figure 1 and shows an enlarged partial cross section of the single rotary mechanical seal of the invention.

Figure 2B corresponds to Figure 2A and shows an enlarged partial cross section of the mechanical seal sliding surfaces and fluid film.

Figure 2C corresponds to Figure 26 and shows the three typical fluid film stages.

Figure 2D corresponds to Figure 2A end shows an alternate ampRfication and data storage device of the invention.

Figure 3A, corresponds to Figure 1 and shows an enlarged partial cross section of a bearing chamber of the invention.

Figure 38, corresponds to Figure 3A and shows an enlarged partial cross section of a ball bearing, in a bearing race with a fluid film FIgure 4, shows a partial cross section of a double stationary seal of the invention.

Figure 5, illustrates a schematic of the condition monitoring system of the invention.

Figure 6, illustrates a schematic of a remote receiver unit of the invention.

Figure 7, illustrates the remote receiver unit of the invention.

Figure 6, corresponds to Figure 7, and shows a schematic of remote receiver with a supplementary power supply.

Figure 9, illustrates an alternate remote receiver unit of the invention, illustrating by way of example only, a supplementary power supply.

Figure 10, illustrates an alternate remote receiver unit of the invention, illustrating by way of example only, a detachable (C) rechargeable battery unit.

Figure 11 illustrates a flow chart for the data acquisition software of the invention.

From Figure 1 the mechanical seal assembly (1) of the invention is installed on a rotating piece of equipment (2). The purpose of the mechanical seal assembly (1) is to prevent process media (14) from the rotating equipment (2).

Figure 2 corresponds to Figure 1. From Figure-2, of the invention, the rotary and axially floating seal face (11) is spring biased towards a static stationary seal face (12). The rotary seal face (11) is allowed to slide on the static seal face (12). The interface between the rotary seal face (11) and stationary seal face (12) forms sealing area (13).

This sealing area (13) is the primary seal that prevents the process media (14) from escaping from the process chamber (15).

In addition to the sliding seal face (13), the process media (14) is sealed by a sleeve elastomer (16) in contact with the shaft (17) and sleeve (18). This has been termed the first secondary seating area.

The second secondary sealing area is formed between stationary seal face (12) and stationary gland plate (19) using elastomeric member (2O) The third secondary sealing area is formed between the rotary seal face (11) and the sleeve (18) using elastomeric member (21).

The fourth secondary sealing area is formed between the gland plate (19) and the process chamber (15) using gasket (3).

A back restriction bush 24 is to prevent a massive leakage to the atmospheric side of the seal.

The four secondary sealing devices (16, 3, 20 and 21) and the primary sding sealing interface (13) prevent the process media (14) from escaping from the process chamber (15).

An acoustic sensor (22) is preferably positioned and secured on the stationary member of the mechanical seal assembly (1), typically the seal gland plate (19). This arrangement of the invention offers many practical and commercial advantages for the supplying party, in that the corresponding mechanical seal components are not modified or compromised from those Which are supplied without the inv9ntion.

This in-direct contact is deemed a considerable inventive step of the present invention forming the first embodiment.

Furthermore, as the acoustic emission sensor (22) is secured on the external feature of the mechanical seal assembly (1) the physical equipment space restraints (2) and/or (15) and/or (17) do not compromise the scope of the inventions application.

Clearly, if deemed appropriate, the acoustic sensor (not shown) could be installed at the back of the stationary seal face (12) instead, or in addition top a sensor (22) on the gland plate (19). The first embodiment of the invention further covers the position of the AE sensor directly on one or more of the sliding members.

From Figure 2, the acoustic emission sensor (22) is permanently attached to the gland plate (19), preferably by adhesive. However it is understood that any other suitable means could be used, including mechanical attachment, chemical attachment and/or physical such as welding or brazing etc. Figure 2U corresponds to Figure 2A and shows an enlarged partial cross section of the mechanical seal sliding surface (13) and fluid film (23) which occupies the axial gap between the two counter sliding members (11) and (12).

Figure 2C corresponds to Figure 2B and shows the three typical fluid film stages, as defined and generally accepted within the mechanical seal industry.

Referring back to Figure 26, the shearing and agitation of the aspirates (24) within the fluid film (23), from the counter rotating of sealing faces (11) and (12), creates and transmits high level energy (25). Said high level energy emissions are gathered by the acoustic emission sensor (22) and stored, by chip (29), by way of example only, locally, adjacent to the sensor (22).

This is shown further by Figure 2D, where the acoustic emission sensor (22) could be connected to an amplifier (27) which In turn is connected to a micro controller (28) and chip (29). The energy thange from the sensor (22) is amplified by the amplifier (27) and a signal sent to the micro controller (28). The micro controller (28) poles the data by checking or comparing the signal information to a benchmark reading and then stamps with the date and time as unique identification number for the recorded sample. This ampIfication arid storage of the AE sensed data forms the 2' embodiment of the invention.

The time-logged information is then 5aved on the chip (29). Clearly a read and write chip (29) is employed so data can be saved and retrieved from the chip (29). It is considered self explanatory to the experienced reader that said chip (29) could be RFID or any wireless data storage device.

This system of the invention, essentially means that at periodic intervals, the energy of vibration from the sliding seal face (13) can be

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recorded, time logged and saved on a chip (29). This energy can be evaluated against a benchmark. Upper and lower energy emissions idealised limits can be established for different fluid film regimes / stages. Measured energy emissions can be compared to idealised seal sliding surface (13) emissions and a precise assessment of the seal face (13) conditions can be made by the user, thus referred as the third embodiment.

It is also possible to record only a part of the received data to reduce the storage space. This is done by the mean of defining a threshold, in which the values above this threshold are saved and the ones below it are Ignored or vice versa.

The third embodiment of the invention is particularly suited for use with non-metallic components, specifically seat face materials (11) and (12) made from Carbon, Ceramic and Silicon Carbon.

From Figure 2D, the chip (29) is preferably sited on the external surface, such as the gland plate (19), of the mechanical seal assembly (1). Since this chip (29) can preferably be remotely read, the user does not have to be near the mechanical seal (1) in order to monitor the information contained on the chip (29).

This condition monitoring system, of the invention and its application thereof, can therefore provide an indication of whether or not the seal (1) is performing well. This information can be used in a preventative maintenance program, to provide an early warning of future seal (1) failure. An experienced reader will relate to the benefits of the third embodiment.

Figure 3a4, corresponds to Figure 1 and shows an enlarged partial cross section of a bearing chamber of the invention (303) Contained within said bearing chamber (303) is at least one ball bearing (304) rotating on an inner most radial bearing race (305) and an outer most radial race (306). Said inner most race (305) is preferably in rotatable contact with the equipment shaft (307) and said outer most race (306) is preferably in rotatable contact with the equipment housing (308).

Said ball bearing (304) is the intermediate sliding member, between the rotating and stationary elements of the equipment.

Figure 3B, corresponds to Figure 3A and shows an enlarged partial cross section of a ball bearing (304), in an inner most (305) and outer most (306) bearIng race In an ideal lubrication regime, the ball bearing has a fluid film (309) between it and the two races (305) and (306). Similar tQ the pre-mentioned mechanical seal sliding surface, the fluid film helps lubricate, cool and carry the load transmitted from the rotating shaft (307) to the stationary housing (308).

It is not uncommon for the fluid film, within the bearing assembly, to be oil, due to its excellent lubrication properties. Often, such bearing assemblies are cited in demanding environments containing water vapour. There are many publications which show the dramatic negative effects of water contamination in a oil filled bearing assembly.

The reader will note that new composite ball bearings are being developed, by suppliers, using high grade ceramics and silicon carbide materials. Such non-metalflc components limit certain condition monitoring techniques, but not that of the present invention The fourth embodiment of the iflvention allows the fluid film regime of a bearing assembly, as found in rotating equipment, to be conditioned monitored via acoustic emission systems.

Figure 4, shows a partial cross section of a double stationary seal (401) of the invention, The present invention accommodates the iS condition monitoring of two or more pairs of sliding surfaces (402) and (403) in a number of ways. The first, and preferred approach is to differentiate the inboard and outboard seal face materials and/or their respective surface finishes of the counter sliding surfaces.

The contact in between the faces t inboard or outboard of the seal can be separately identified by the use of separate AE sensor, connected directly the one of the faces in this area, or within the gland, where Iwo parts of the gland are isolated from each other.

Figure 5, illustrates a schematic of the condition monitoring system of the invention.

From Figure 5, it will be noted that signals from any number of the aforementioned sensors (100), located in the mechanical seal (101), are taken into at least one micro-controller (102). The micro-controller (102) processes the data and stores it in the chip (103). Clearly data samples can be taken over the most appropriate time intervals.

The chip (103) is ideally located on the mechanical seal (101) As the user walks around the plant, he/she may then scan the mechanical seal (101) using a remote, hand held health monitor (104). This will be explained later with reference to Figure 6.

Alternatively, users in large plants can install local health monitor repeaters (105) around the plant. This remotely scans the respective chips (103). Each chip (103) has a unique wireless connectivity or reference code thereby the user is able to separate gathered information from more than one piece of equipment.

The local remote health monitor repeater (105) then transmits the information by wireless technology (106) to a network (107) and/cr internet server using health monitor software (108). 1k,

For the purpose of this application, wireless technology includes, but is not limited too; Internet, Satellite, WAP (wireless application protocol) phones, LAN (local area network), WLAN (wireless local area network), field bus connector, WEP (wireless encryption protocol) arid blue tooth. Clearly hard wire technology can also be employed. The experienced reader will understand that this technology also allows the health monitor software to dial and send a message to a mobile cell phone, if required.

Figure 6, illustrates a schematic of a remote receiver unit of the invention. The remote receiver (110) is employed by the user to revIew the health status on a particular rotating equipment application as the user attends site.

Figure 6, illustrates, by way of example only, a series of components situated inside a casing (11 1). The communication, in the example below, is termed RFID, however the experienced reader will note that it is not limited to such.

The RFID receiver (112) is connected to a RFID ansI I external antennae (113). The RFID receiver (112) receives the sensor data from the application, which is stored in the RFIO chip previously described. The RFID receiver (112) sends the data to a micro controller (114). The micro controller (114) sends the information to a VFD display (115) which, is connected to a suitable power supply, in this case a battery (116). The display (115) is also connected to an earth terminal (117).

The micro controLler (114) is preferably connected to one or more user control switches (118). Said switches (118) are connected to user control buttons (119) as shown in Figure 12. From Figure 11 said switches (118) are also connected to an earth terminal (119).

From Figure 6, the micro controller (114) is connected to a power switch (120) which, if activated connects the circuit to the power supply (116) therefore providing user operating power to the micm controller (114).

Furthermore, the micro controller (114) is connected to an external EEP ROM (electrically erasable programmable read only memory) data storage device (121), which in turn is connected to the power supply (116) and earth terminal (122). This allows the user to save collected data, then at a later date said stored data from the storage device (121) can be transferred through the 9 pin D-Type RS232 serial connector (123) to a computer or subsequent data processing device. Clearly, an alternate connector device (123) such as a 21 pin or 6 pin design, may be used where appropriate.

Preferably, a'though not essentially, the micro controller (114) is also connected to an LED (Light emitting diode) visual display unit (124), which in turn is connected to a power supply (116) and earth terminal (125). The LED display unit (124) is a user friendly display, which illustrates whether the process application and sensory devices are out of the pre-specified sensor control limits.

At least one LED display (124) unit is employed in the remote unit of the invention but preferably three LED displays are employed. Said LED displays are preferably coloured green" (126), orange" (127) and "red" (128). If the application sensor(s) are in control, the green LED displays(126), if the process sensors are moving towards the control limits, the orange LED displays (127) and if the process sensors are out of the control limits, the red LED displays (128), Figure 7, corresponds to Figure 6 and illustrates the remote receiver unit of the invention (110). The outer casing (111) covers the components and electrical circuit previously described with the aid of Figure 6.

Also, from Figure 7, a graphic illustration of the display (115), LED display (124), 0-Type RS232 connector (123), RFID antennae (113) and user buttons (119) may be seen.

Clearly, an experienced user will understand that there are many alternate graphic representations of the remote unit (110), which may be offered to a user. Said remote unit options may have a range of different functions and I or technical sophistication.

Figure 8, corresponds to Figure 6, but shows a schematic of remote receiver with a supplementary power supply.

The micro controller (130) is connected to a power switch (131) which, if activated connects the circuit to the power supply (132) therefore providing power to the micro controller (130). From Figure 12, the power switch (131) is connected to at least one transistor (133). The transistor (133) i5 connected to at least two power supplies, the first is a solar cell (134) and the second is a battery (135).

When the power switch (131) is activated, the transistor (133) preferably sources power supply from the solar cell (134). In applications where there is insufficient power generated by the solar cell (134), the transistor (133) sources power supply from the battery (135), until suth a time when the minimum power level is achieved by the solar cell (134). The transistor (133) then switches the power source to the solar cell (134) thereby elongating the finite baftery (135) life.

It is self explanatory to an experienced reader that a rechargeable battery (135) could be employed in such a design of the invention.

This thereby aflows the solar cell (134) to recharge the battery (135) when the battery (135) is not in use.

In a design, of the invention, which does not contain a solar cell (134), as shown in Figure 7, the rechargeable battery (135) could be charged by connecting the device to an AC/DC adapter or portable unit as found in most automobiles.

Figure 8 illustrates a large quantity of LED displays (136). Figure 9 shows that these can be positioned either side of the display (140) allowing the user to visually display the sansored detail wIth respect to the control limits (142) on the displayed screen.

Figure 9, corresponds to Figure 8 and illustrates an alternate remote receiver (148) unit of the invention. The outer casing (143) covers the components and electrical circuit previously described with the aid of Figure 8.

Also, from Figure 9, a graphic illustration of the display (140), LEO display (136), 0-Type R8232 connector (144), RFID antennae (145), keypad (146) and AC power connector (147) may be seen.

It is clear from Figure 9 that the keypad (146) containing both alpha and numerical option would allow the user to program the remote device (148), independent of a separate computer. This provides the user with added technical sophistication.

From Figure 10, an alternate graphic representation of the remote unit (150), may be seen, illustrating by way of example only, a detachable battery unit (151) Figure 11 illustrates a flow chart for the data acquisition software of the invention.

From Figure 11, the user logs on (160) to the application. If the user does not have an appropriate application password, he/she may apply (161) for one. Once the user password is submitted, the application reviews the user authorisation (162). Certain users may have read only authorisation and certain users may have read and wite authorisation. The user then obtains andlor enters the variables for the application into the software (163). Clearly such vartables could be retrieved from a database (164) if required.

Said variables are then transmitted to data collection hardware (166).

Clearly transmitted data is directed through a security review (185).

After the software has checked the data authenticity (165), then item attendant information is collected via RFID or any suitable data transmission device (167). Said data is continuously monitored (168) and could be saved to the database (164) as historical data.

If the user has inputted or retrieved Incorrect variable data, the user is directed back to the input area (183).

The software algorithm, of the invention, compares the authenticated input data against the data acquisition stream and/or history (169).

The output (170) is then shown as a process health status. The software of the invention may then suggest possible remedial actions (171), or allow the user to print (172) and/or send the data to an alternate application (173).

The output results are preferably logged in a database (164) for future use.

If remedial action (171) is taken, or if data is entered into the database (164), the application returns the user to the item attendant information collected point (167) The user may reiterate collection and storage sequences until such a time when the user wishes to move onto the next piece of equipment to be measured.

At such time, the appkcation sends the user to the variable entering point (163).

The intelligent aspects of the system, including remote access and remedial corrective action, either manually or automatically activated, forms the sixth embodiment of the invention.

It wifl be apparent to art experienced reader, that the design and application scope of the invention has considerable advantages in that the technology allows the remote condition monitoring of a given mechanical seal application so that the user can receive prior warning of pending problems.

It will be further noted that the de8ign of the invention can be adapted for intrinsically safe applications also. By way of example only, to achieve this the electronics could be designed to run below a certain power! amp level. Alternatively the electronics could be sealed in a media which insulates them. Such a media could be bitumen.

Clearly flameproof applications are dealt with in a similar manner to the above. The items which could create a spark, or melt I deteriorate under certain thermal conditions, can be sealed in a flameproof container.

The reader will therefore note that the design of the Invention, containing A sensoring devices, may be applied to any type of mechanical seal assembly whether designed as a Stationary, Rotary, Double, Single or Triple seal, component or cartridge with hydraulically balanced or unbalanced seal faces Some single andlor double mechanical seals have a three seal face design, incorporating an intermediate face, whtch runs between the rotary seat face and stationary seal face. Clearly the invention is applicable for such designs also.

Furtherniore, the design of the invention may be applied to complex assemblies operating in fluctuating variable operating conditions for standard or sensitive applications.

Clearly, some applications may necessitate very accurate sensory measurements. In such applications the sensors of the invention are calibrated and the readings verified, at least once, but preferably in periodic time intervals.

Furthermore, the experienced reader wilt understand that since the mechanical seal of the invention contains product assembly and/or serial identification data stored on the data storage chip, this information may be used for other purposes. Such purposes include inventory identification, while the product is on shelf, or product tracking should the product be used for a different application which it was not intended for.

Summary of Embodiments

1' embodiment is summarised as the preferable indirect contact of AE sensor, secured to the gland plate or stationary member of the rotating equipment, thereby allowing the technology to be employed in physically constrained applications, without modification of seat components.

2' embodiment is the amplification and storage of the AE emission data, preferably relatively local and adjacent to the emission source of the rotating equipment 3rd embodiment is the ability of the system to compare time logged AE emission data, to predefined benchmark data, such as fluid film stages, to allow the user to determine whether the process is moving out of control, into non-idealised conditions of operation. The 3Td embodiment further covers the remote access to the stored data, ideally at plant level, or via wireless telecommunications such as satellite, WAP, internet, RFID etc. 4 embodiment is the ability of the AE emission system to condition monitor rolling bearings in bearing chamber applications 5th embodiment is the ability of one AE emission sensor to monitor multiple counter-sliding members, preferably in dual seals.

6" embodiment is the ability of the system to be intelligent, thereby automatically changing the condition of a fluid film, by appropriate remedial actions1 when the system determines boundary conditions are approaching.

The 7"' embodiment is the noise filtration system, of the invention, allowing the AE emission sensors to focus on the object energy emissions rather than other sources.

Claims (1)

1. Claims: I A condition monitoring system comprising of at least one

   acoustic emission sensory device and at least one data storage device, said acoustic emission sensory device measures variable information and store said information on said storage device 2 A condition monitoring system comprising of at least one pair of counter-sliding surfaces on an item of rotating equipment, said counter- sliding surfaces emit energy which is sensed by an acoustic emission sensory device, said energy is preferably, although not essentially amplified and stored on a data storage device, said sensory device measure variable information with respect to a time log.

   3 A condition monitoring system in accordance with any preceding claims, where said sensor device is permanently fixed or non- permanently attached to a component of the couter-sliding assembly, said sensor device is connected to an amplifier and/or a micro controller and a data storage device.

   4 A condition monitoring system in accordance with any preceding claims, where said data storage device is accessed by a remote unit consisting of a display, and/or keypad and remote antennae or receiver.

   A mechanical seal arrangement in accordance with any preceding claims, which contains at least one acoustic emission sensory device, which sensors the energy emissions from at least one pair of counter-rotating mechanical seal faces, said sensor is in direct contact with one or more said counter rotating seal faces. as

   6 A mechanical seal arrangement in accordance with any preceding claims, which contains at least one acoustic emission sensory device located on the mechanical seal gland plate or rotating equipment stationary member/housing.

   A mechanical seal arrangement in accordance with any preceding claims, which contains at least one acoustic emission sensory, and at least two pairs of differentiated seal faces.

   8 A mechanical seal arrangement in accordance with any preceding claims, which contains at least one acoustic emission sensory, and at least two pairs of seal faces, one or more seal faces of the first pair has a substantially different counter-sliding surface finish co- efficient of friction, to one or more seal faces of the second pair.

   9 A bearing assembly in accordance with any preceding claims, which contains at least one acoustic emission sensory device located on the nonrotating member of the rotating equipment.

   10 A condition monitoring system for a bearing assembly, in an item of rotating equipment, in accordance with any preceding claims, which contains at least one acoustic emission sensory device and at least one roller and/or ball type rolling element between the counter rotating surfaces, said rolling element emits energy which is sensed by the acoustic emission sensory device, said energy is preferably, although not essentially amplified and stored on a data storage device, said sensory device measure variable information with respect to a time log.

   11 A condition monitoring system in accordance with any preceding claim, where said information 5tored is remotely accessed by wireless technology. ao

   12 A condition monitoring system in accordance with any preceding claim, where said information stored is remotely accessed by wireless technology including RFIDI WAP, WEP, WIAN, Blue Tooth, Internet, Phones, Satellite and all other wireless systems.

   13 A condition monitoring system in accordance with any preceding claim, where said information stored is remotely accessed by non- wireless technology.

   14 A condition monitoring system in accordance with any preceding claim, where said information stored is accessed by non-wireless technology including LAN, Cable, hard wiring, Field Bus Connector and all other nonwireless systems.

   15 A condition monitoring system in accordance with any preceding claim, whereby the collected data from the AE emission source is compared to predefined benchmark data.

   16 An intelligent system in accordance with any preceding claims, where said data is process by a software application with the sophistication to advise remedial process actions.

   17 A condition monitoring system in accordance with any preceding claim, which incorporates a background noise filtration system.

   18 A condition monitoring system in according to claim I and claim 2 and substantially as herein described.

   19 Applications of acoustic emission energy sensoring in rotating equipment, particularly, but not limited too, mechanical seal and bearing assembly counter sliding surfaces, as herein described.

   A condition monitoring system according to Figures 1 to 11