Method of operating a seal monitoring system and seal monitoring system for a seal

Abstract

The invention relates to a method of operating a seal monitoring system (10) in a seal (11) of a rotatable shaft (14), comprising a seal (11) provided with a flushing liquid system (32) between the rotatable shaft (14) and a stationary housing (22), a first liquid detector (40) configured to detect the presence of a flushing liquid in the flushing liquid system (32), the method comprising: - detecting a first flushing liquid presence state in the flushing liquid system by the first liquid detector (40), and a) in case the first flushing liquid presence state is positive, using a wireless data communication system (36) to transmit the first flushing liquid presence state for further processing with a first data transmission interval between transmissions, and b) in case the first flushing liquid presence state is negative, using the wireless data communication system (36) to transmit the first flushing liquid presence state for further processing with a second data transmission interval between transmissions which is shorter than the first transmission interval.

Description

Technical Field

[0001] The invention relates to a method for operating a seal monitoring system in a seal of a rotatable shaft. The invention also relates to a seal monitoring system for a seal connected to a rotatable shaft, comprising a flushing liquid system, the seal being arranged between the rotatable shaft and a seal housing. Background Art

[0002] The present invention relates to monitoring mechanical seals in pumps or similar fluid handling machines having a mechanical seal on their rotatable shaft. Mechanical seals are gaining increasing acceptance in various shaft sealing applications. They can be used in various pumps, mixers, and agitators. Mechanical seals have a relatively simple structure, are resistant to high temperatures, and are relatively easy to maintain and service. However, like all types of seals, their lifespan is difficult to predict. It is also quite impossible to visually monitor the condition of the seals. Failure of such seals can result in considerable damage and additional costs. Consequently, the prior art includes numerous documents discussing monitoring the condition of mechanical seals.

[0003] EP 3139072 A1 discloses an apparatus for monitoring one or more components of a propulsion system of a vessel. A plurality of sensors are arranged to a mechanical seal of a drive shaft, and information obtained by the sensors is sent to a controller configured to provide an estimated remaining life of the mechanical seal.

[0004] WO 2018210504 A1 discloses a mechanical seal having a rotating component and a non-rotating component. The rotating component comprises at least a rotating slip ring and a rotating slip ring carrier, and the non-rotating component comprises at least a non-rotating slip ring and a non-rotating slip ring carrier. The mechanical seal is provided with a circumferential groove in one of the rotating and non-rotating slip rings, and a sensor in communication with the mechanical seal.

[0005] US Patent No. 6,065,345 A discusses a method for monitoring the condition of a mechanical seal in a device equipped with a rotating component, particularly a pump having a rotating shaft for conveying a fluid. While the device is in operation, acoustic emissions from the seal are continuously measured at discrete times, and at least one statistical characteristic value is derived from the acoustic signal. The objective of this patent is to monitor the sliding condition of the seal. In other words, if the seal begins to dry out—that is, if flushing is ineffective for some reason—the acoustic emissions from the seal will change with the condition of the lubricating film.

[0006] US Pat. No. 6,360,610 B1 discusses a system and method particularly suitable for monitoring the interface of two liquid-lubricated mechanical seal surfaces. The system monitors the interface by generating ultrasonic shear waves using a wave source, directing the waves toward the interface, detecting the waves after they interact with the interface, and comparing the detected waves to a predetermined wave signature. Based on this comparison, an alarm can be triggered.

[0007] EP 1510698 B1 discloses a pump provided with a device for protecting the pump from dry running. The pump is provided with a sensor by which the filling level at the mechanical seal area is detected and if no liquid is detected, activation of the pump can be prevented.

[0008] It is also known to use a wireless monitoring system to monitor mechanical seals. As an example of this, it is referred to as publication MX 2011003615A, which discloses collecting lubrication information and equipment vibration information of a mechanical seal through a wireless data transmission system.

[0009] However, there is still a need to further improve the operational reliability of mechanical seals.

[0010] It is an object of the present invention to provide a method of operating a seal monitoring system in a mechanical seal of a rotatable shaft, wherein the performance is significantly improved compared to prior art solutions.

[0011] A further object of the present invention is to provide a seal monitoring system which is a significant improvement over prior art solutions. Summary of the Invention

[0012] The objects of the invention may be achieved substantially as disclosed in the independent claim and in the further claims, which describe further details of different embodiments of the invention.

[0013] According to the present invention, there is provided a method of operating a seal monitoring system in a seal of a rotatable shaft, comprising a seal provided with a flushing fluid system between the rotatable shaft and a stationary housing, and a first liquid detector configured to detect the presence of flushing fluid in the flushing fluid system, the method comprising:

[0014] detecting the presence of the first flushing liquid in the flushing liquid system by a first liquid detector, and

[0015] a) if the first flushing fluid presence status is positive, transmitting the first flushing fluid presence status for further processing using the wireless data communication system with a first data transmission interval between transmissions, and

[0016] b) If the first rinsing liquid presence status is negative, transmitting the first rinsing liquid presence status for further processing using the wireless data communication system at a second data transmission interval between transmissions that is shorter than the first transmission interval.

[0017] By means of the present invention, since the data transmission interval is changed based on the state of the flushing fluid and unnecessary energy consumption can be minimized, information on the state of the flushing fluid, and in particular possible failure of a seal in an apparatus provided with a rotatable shaft, can be obtained in real time and over a long period of time even at a remote or unmanned location.

[0018] According to one embodiment of the present invention, the first liquid detector intermittently detects the presence status of the liquid, and when the presence status of the first flushing liquid is positive, uses a first detection interval to detect the presence status of the first flushing liquid in the flushing liquid system, and when the presence status of the first flushing liquid is negative, uses a second detection interval shorter than the first detection interval to detect the presence status of the first flushing liquid in the flushing liquid system.

[0019] In this way, the seal monitoring system uses only a minimum amount of energy when interruptions are provided between the transmissions and / or when the intervals between the transmissions are varied based on the presence of flushing fluid, whereby its independence is at a high level.

[0020] According to one embodiment of the present invention, the first liquid detector continuously detects the presence of liquid.

[0021] According to one embodiment of the present invention, in the case where the first flushing fluid presence status is affirmative, the wireless data communication system is set to idle between data transmissions.

[0022] According to one embodiment of the present invention, when the first flushing liquid presence status is affirmative, the first data sending interval exceeds one hour.

[0023] According to one embodiment of the present invention, when the first flushing liquid existence state is affirmative, the first data sending interval is greater than 4 hours.

[0024] According to one embodiment of the present invention, when the first flushing liquid presence status is positive, the first data sending interval is infinite. In this case, only when the first flushing liquid presence status is negative again, the first flushing liquid presence status is sent for further processing.

[0025] According to one embodiment of the present invention, when the first flushing liquid presence status is negative, the second data sending interval is less than 60 seconds.

[0026] According to one embodiment of the present invention, the sealing monitoring system is provided with a vibration sensor unit, and the method includes detecting vibration information of the shaft of the equipment, and determining the rotation state of the shaft based on the vibration information, and when the first flushing liquid presence state is positive, using the first data sending interval between sending to send the vibration information for further processing, and when the first flushing liquid presence state is negative, using the second data sending interval between sending to send the vibration information for further processing.

[0027] According to one embodiment of the present invention, the sealing monitoring system is provided with a vibration sensor unit, and the method includes detecting vibration information of the shaft of the equipment, and determining the rotation state of the shaft based on the vibration information, and when the first flushing liquid presence state is positive, using the first data sending interval between sending to send the vibration information for further processing, and when the first flushing liquid presence state is negative, using the second data sending interval between sending to send the vibration information for further processing, and reducing the interval for detecting the vibration information of the shaft of the equipment.

[0028] According to one embodiment of the present invention, vibration information is used to determine whether the shaft is rotating. If the first flushing fluid presence status is negative, the vibration information is used to determine whether the shaft is rotating, and if the shaft is rotating, the first flushing fluid presence status is transmitted using a wireless data communication system at a second data transmission interval shorter than the first transmission interval between transmissions for further processing.

[0029] According to one embodiment of the present invention, when the presence of the first flushing fluid is positive, a wireless data communication system is used to transmit the presence of the first flushing fluid for further processing with a first data transmission interval between transmissions, detect the occurrence of transmission, and trigger an alarm signal if the occurrence of transmission cannot be positively confirmed. When the first data transmission interval is stored or available for use in a transceiver unit, the omission of transmissions within the interval can be used to detect problems in the transmission process. In this way, the charge of a battery providing power to the wireless data communication system can be actively monitored, for example.

[0030] According to one embodiment of the present invention, the sealing monitoring system is provided with a vibration sensor unit, and the method includes detecting the startup moment of the device and defining a first flushing liquid presence state at the startup moment of the device, and when the first flushing liquid presence state is negative, sending an exception message for further processing, the exception message including information that the seal is running dry.

[0031] According to one embodiment of the present invention, the flushing fluid system includes a node to which a first flushing fluid presence status is transmitted using a wireless data communication system, and from which the first flushing fluid presence status is transmitted using the wireless data communication system for further processing. More generally, all sensors of the seal monitoring system are arranged to communicate with the node, which transmits the communication data via the Internet for further processing.

[0032] The present invention also relates to a seal monitoring system for a seal in a device, comprising a rotatable shaft, a flushing liquid system, the seal being arranged between the rotatable shaft and a housing, wherein the seal monitoring system comprises a first liquid detector configured to detect the presence of flushing liquid in the flushing liquid system, a data processing device configured to receive data from the first liquid detector, and a wireless data communication system connected to the data processing device for data transmission, wherein the data processing device comprises:

[0033] - executable instructions for detecting the presence of a first flushing fluid in the flushing fluid system,

[0034] - executable instructions for determining a first flushing liquid presence status as positive when flushing liquid is detected in the flushing liquid system, or determining a first flushing liquid presence status as negative when flushing liquid is not detected in the flushing liquid system,

[0035] - executable instructions for transmitting a first flushing fluid presence status for further processing using a wireless data communication system at a first data transmission interval if the flushing fluid presence status is positive, and

[0036] - executable instructions for transmitting the first flushing fluid presence status for further processing using the wireless data communication system at a second data transmission interval between transmissions that is shorter than the first transmission interval if the flushing fluid presence status is negative.

[0037] According to one embodiment of the present invention, the first flushing fluid presence status, the second flushing fluid presence status and / or the vibration status are transmitted to a remote data server, which makes it possible to use the data for various purposes.

[0038] According to one embodiment, the first liquid detector is configured to intermittently detect the presence of the flushing liquid, and the data processing device includes executable instructions for detecting the presence of the first flushing liquid using a first detection interval when the presence status of the first flushing liquid is affirmative, and executable instructions for detecting the presence of the first flushing liquid using a second detection interval shorter than the first detection interval when the presence status of the first flushing liquid is negative.

[0039] According to an embodiment of the invention, the first liquid detector is configured to continuously detect the presence of flushing liquid.

[0040] According to one embodiment of the present invention, the data processing apparatus includes executable instructions for arranging the wireless data communication system to idle between transmissions.

[0041] According to one embodiment of the present invention, the data processing apparatus includes executable instructions for transmitting the first flushing fluid presence status for further processing using a wireless data communication system at a first data transmission interval exceeding one hour if the flushing fluid presence status is affirmative.

[0042] According to one embodiment of the present invention, the data processing device includes executable instructions for transmitting the first flushing fluid presence status at a first data transmission interval greater than 4 hours when the flushing fluid presence status is positive.

[0043] According to one embodiment of the present invention, the data processing apparatus comprises executable instructions for transmitting the first flushing liquid presence status at an infinite first data transmission interval if the flushing liquid presence status is affirmative.

[0044] According to one embodiment of the present invention, the data processing apparatus includes an executable instruction for setting the second data sending interval to be less than 60 seconds.

[0045] According to one embodiment of the present invention, the seal monitoring system includes a node configured to communicate with a gateway to the Internet, and the first liquid detector is configured to communicate with the node. Advantageously, the node is a standalone device disconnected from the mains power grid, and the node is provided with a dedicated power storage battery that provides power to operate any power consumer in the node for a period of more than 1 month.

[0046] According to one embodiment of the present invention, the seal monitoring system includes a second liquid detector configured to detect the presence of liquid outside the flushing liquid system, and the second liquid detector is configured to communicate with a node, and the node is configured to communicate with a gateway to the Internet and transmit data obtained by the first liquid detector and the second liquid detector to the gateway.

[0047] According to one embodiment of the present invention, the seal monitoring system comprises a second liquid detector configured to detect the presence of liquid outside the flushing liquid system, and the data processing device is configured to receive data from the second liquid detector, wherein the data processing device further comprises:

[0048] - executable instructions for detecting the presence of a second flushing fluid external to the flushing fluid system,

[0049] - executable instructions to determine a second flushing fluid presence status as positive when flushing fluid is detected to be present outside the flushing fluid system, or to determine a second flushing fluid presence status as negative when flushing fluid is not detected to be present outside the flushing fluid system, and

[0050] - executable instructions for transmitting the second flushing fluid presence status for further processing using the wireless data communication system at a second data transmission interval if the second flushing fluid presence status is affirmative.

[0051] A data processing device is a computer processor that incorporates the functionality of a central processing unit on one or more integrated circuits (ICs). A data processing device may be a clocked, register-based digital integrated circuit that accepts binary data as input, processes it according to instructions stored in its memory, and provides a result as output.

[0052] Various advantageous effects and functions can be achieved. For example, equipment provided with seals can be efficiently monitored in remote locations. The seal monitoring system according to the present invention also makes it possible to provide efficient monitoring of multiple equipment in a direct and economical manner even at remote locations.

[0053] The exemplary embodiments of the invention given in this patent application should not be interpreted as imposing limitations on the applicability of the appended claims. The verb "comprise" is used in this patent application as an open limitation that does not exclude the presence of unrecited features. Unless expressly stated otherwise, the features recited in the dependent claims are freely combinable with one another. The novel features considered as characteristic of the invention are set forth with particularity in the appended claims.

[0054] Liquid detectors are known to those skilled in the art as such. There are many known principles that can be used to detect the presence of liquids, based on the use of optical, ultrasonic, levitation, capacitance, radar or conductive or resistive properties based on the presence or absence of liquid. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] The present invention will now be described with reference to the accompanying exemplary schematic diagrams, in which:

[0056] Figure 1 A seal monitoring system for a mechanical seal according to one embodiment of the present invention is shown;

[0057] Figure 2 A seal monitoring system for a mechanical seal according to another embodiment of the present invention is shown;

[0058] Figure 3 A seal monitoring system for a mechanical seal according to another embodiment of the present invention is shown;

[0059] Figure 4 A flowchart illustrating a method according to one embodiment of the present invention; and

[0060] Figure 5A seal monitoring system for a mechanical seal according to yet another embodiment of the present invention is shown. DETAILED DESCRIPTION

[0061] Figure 1 The device 1 or its related parts is schematically depicted, wherein a shaft 14 is rotatably supported in a body 22 and a mechanical seal 11 is arranged to the rotatably supported shaft 14. The shaft and the device are operated by a motor 17 coupled to the shaft 14 so as to seal the inside of the device from the outside of the device. Figure 1 In the illustrated embodiment, the seal 18 includes a rotating portion 24 and a non-rotating portion 26 . Figure 1 The rotating part 24 in the embodiment includes a retaining ring, a rotating slip ring carrier and a rotating slip ring 28. The rotating slip ring 18 is attached to the axial end of the rotating slip ring carrier. The non-rotating component 26 includes a non-rotating slip ring carrier, a non-rotating slip ring 30 and a pressure ring. The non-rotating slip ring 30 is attached to the end of the non-rotating slip ring carrier. When used in a fluid machine, the slip rings 28 and 30 are in mechanical contact with each other. Figure 1 In addition to the components shown, the mechanical seal 11 may include an O-ring, a drive pin, a set screw, and a bolt, but these are not discussed in further detail because they are not relevant to explaining the present invention. The contact surface between the rotating slip ring 28 and the non-rotating slip ring 30 serves as the primary seal of the mechanical seal 18. The seal 11 is described here primarily for the purpose of understanding the seal monitoring system 10, and it can be constructed in a variety of ways.

[0062] The mechanical seal 11 of the device 1 is provided with a flushing liquid system 32. Figure 1 In the drawings, the flushing liquid system 32 is generally shown as part of a conduit leading to the seal chamber 20, indicating that flushing can be achieved in various ways known to those skilled in the art. In some cases, the flushing liquid can be, for example, a process liquid that equipment (such as a pump) is arranged to dispose of. The purpose of the flushing liquid system is to circulate fluid to or from the seal chamber 20 in order to maintain proper lubrication, pressure, temperature and solids management. The goal is to create an ideal working environment for the seal 11 so that wear and failure are minimized, thereby extending its service life. Any liquid that is available and suitable for the purpose can be used as a flushing liquid. The present invention is naturally also applicable to, for example, double-acting mechanical seals. The mechanical seal 18 is used to seal the shaft 14 of, for example, a fluid machine 16 (such as a centrifugal pump, agitator, mixer, etc.). The mechanical seal 18 is configured so that the interior of the fluid machine (in Figure 1 The mechanical seal is located in a seal chamber 20 which is provided within a specific seal housing or housing cover 22 of the fluid machine. The present invention is also applicable to other types of seals associated with rotatable shafts, such as gland packings.

[0063] The device 1 comprises a seal monitoring system 10 which is arranged in connection with a seal 11 of the device. The seal monitoring system 10 comprises a first liquid detector 40 which is arranged in connection with the flushing liquid system 32. Figure 1 In FIG, the seal 11 is a mechanical seal including a single-acting mechanical seal 18 shown schematically and exemplarily arranged between a rotatable shaft 14 and a stationary seal housing 22. The seal monitoring system 10 is configured and adapted to detect the operation and condition of the mechanical seal 11 including the flushing fluid system and the seal. The first liquid detector 40 is configured to detect the presence of flushing fluid in the flushing fluid system 32. Figure 1 , it is depicted that the first liquid detector 40 may be disposed in either or both of the seal chamber 20 itself and the conduit leading to the seal chamber 20. This should be understood so that the actual location of the first liquid detector may vary depending on the circumstances, as long as it is positioned so that the presence of flushing liquid adjacent the mechanical seal 18 can be reliably detected or determined. The flushing liquid may be a water-based solution, advantageously water, in which case the liquid detector is a water detector.

[0064] according to Figure 1 The seal monitoring system 10 of one embodiment includes a body or housing 12 that houses at least some of the components belonging to the seal monitoring system 10. The housing and its components may be referred to as nodes, and thus reference numeral 12 is also used to denote a node. The node may be provided with predetermined sensors, such as Figure 1 The node 12 of the seal monitoring system 10 includes a wireless data communication system 36, through which data generated by the data processing device 34 provided in the node 12 and / or the sensors connected to the node 12 can be sent for further processing, such as to a data storage device, a user console, a cloud service, etc. The data can be used for general monitoring of the operation of the device 1 or for sending process data such as alarms to a mobile device of an operator of the device 1. The node 12 is a stand-alone unit, which includes at least a first liquid detector 40 and a data processing device 34. The node 12 is removably and securely attached to the sealed housing 22 of the device 1. The seal monitoring system 10 includes a data processing device 34 or a system such as a microprocessor, which is configured to receive data from the first liquid detector 40 including a sensor. The data processing device 34 includes an executable computer program, that is, executable instructions, which, when executed by the data processing device, cause the seal monitoring system 10 to perform the method described in any of the accompanying method claims.

[0065] The data processing device 34 of the node 12 is configured to receive data from the first liquid detector 40 to determine the presence of flushing fluid. A wireless data communication system 36 is connected to the data processing device 34 in the node 12 for data transmission. The wireless data communication system 36 enables the seal monitoring system 10 to communicate wirelessly with auxiliary equipment, and in this way also provides communication to the Internet. According to a preferred embodiment of the present invention, the seal monitoring system 10 includes a dedicated electrical energy storage device 33, such as a battery or a rechargeable battery. The energy storage device 33 provides power for operating the components of the seal monitoring system 10 and is optionally connected to the seal monitoring system 10. The electrical energy storage device 33 has the capacity to provide energy for operating the seal monitoring system 10 for a period of several months without being connected to a main power source. Even though only some of the figures show the energy storage device 33, the energy storage device 33 is also provided in the seal monitoring system 10 shown in other figures. The data processing device 34 includes executable instructions to detect the presence of the first flushing fluid in the flushing fluid system 32, which can be executed using a first detection interval. Advantageously, the computer program includes executable instructions for determining a data transmission interval for node 12 to forward the first flushing fluid presence status for further processing. The first data transmission interval is based on the first flushing fluid presence status. According to the present invention, the computer program includes executable instructions for detecting the first flushing fluid presence status of flushing fluid system 32, and executable instructions for determining that the first flushing fluid presence status is positive when the presence of flushing fluid in flushing fluid system 32 is detected or negative when the presence of flushing fluid in flushing fluid system 32 is not detected, and further executable instructions for transmitting the first flushing fluid presence status for further processing using wireless data communication system 36 at a first data transmission interval if the flushing fluid presence status is positive, and executable instructions for transmitting the first flushing fluid presence status for further processing using wireless data communication system 36 at a second data transmission interval between transmissions that is shorter than the first transmission interval if the flushing fluid presence status is negative.

[0066] In this way, the sealing monitoring system 10 can be operated so that when the first flushing liquid presence status is positive, the first flushing liquid presence status is sent for further processing using the wireless data communication system 36 at a lower frequency than when the first flushing liquid presence status is negative, which in turn saves or reduces the energy consumption of the node 12 and increases the charging interval or change interval of the energy storage device 33.

[0067] In other words, the computer program includes executable instructions for determining the transmission interval based on the first rinsing fluid presence status, such that the transmission interval is shorter if the first rinsing fluid presence status is negative, i.e., if no rinsing fluid is detected in the rinsing fluid system 32. The node 12 is advantageously a standalone device, which is advantageously provided with a dedicated power source, such as a battery or accumulator 33. The node 12 being a standalone device is made possible by the energy storage device 33, such as a battery or accumulator.

[0068] According to one embodiment of the present invention, the executable instruction sets the second data transmission interval to be less than 60 seconds when being executed. In this way, when the first flushing liquid presence status is negative, the status is frequently updated.

[0069] To minimize energy consumption of the seal monitoring system 10, the data processing device advantageously includes executable instructions for idling the wireless data communication system 36 between transmissions. Thus, when the flushing fluid presence status is positive, status information is only transmitted infrequently, further reducing energy consumption of the seal monitoring system 10 and extending the useful service life of the energy storage device 33 (on a single charge, if rechargeable).

[0070] According to one aspect of the present invention, the data processing device includes executable instructions for transmitting the first flushing fluid presence status using the wireless data communication system 36 at a first data transmission interval greater than one hour for further processing if the flushing fluid presence status is positive.

[0071] According to another aspect of the present invention, the data processing device includes executable instructions for transmitting the first flushing fluid presence status at a first data transmission interval greater than 4 hours.

[0072] According to another aspect of the application, the data processing device comprises executable instructions to send the first flush liquid presence status in case the first data sending interval is infinite. In other words, according to this aspect, the computer program in the data processing device 34 comprises executable instructions to never send the first flush liquid presence status or to not send the first flush liquid presence status until the flush liquid presence status changes to negative in case the flush liquid presence status is positive. In this embodiment, the data sending is self-activated, so that the computer program in the data processing device 34 comprises executable instructions to detect the first flush liquid presence status in the flush liquid system by the first liquid detector and to start sending the first flush liquid presence status for further processing if the first flush liquid presence status changes to negative (no liquid detected status) and to keep sending using the wireless data communication system 36 with a data sending interval of less than 60 seconds. In this way, the information of the lack of flush liquid is obtained without excessive delay and at the same time the service period of the energy storage device 33 is obtained.

[0073] The first liquid detector 40 can be configured or constructed to intermittently detect the presence of flush liquid. In this case, the data processing device 34 of the node 12 comprises executable instructions to detect the first flush liquid presence status using a first detection interval in case the first flush liquid presence status is positive and executable instructions to detect the first flush liquid presence status using a second detection interval shorter than the first detection interval in case the first flush liquid presence status is negative. In other words, if based on the signal of the liquid detector there is no liquid in the flush liquid system 32, the presence of liquid is detected more often. The first detection interval is therefore employed when the first flush liquid presence status is positive.

[0074] The first liquid detector 40 of the seal monitoring system 10 according to one embodiment of the application is configured to continuously detect the presence of flush liquid.

[0075] Figure 2 One embodiment of the application is schematically shown, according to which, Figure 1 The seal monitoring system 10 as shown in Fig. 1 has an additional optional feature which brings additional functionality to the apparatus 1 and the seal monitoring system 10. Namely, the seal monitoring system 10 comprises a first liquid detector 40 as disclosed in Figure 1 Fig. 1 and an additional second liquid detector 41. The second liquid detector 41 is configured to detect the presence of liquid outside the flush liquid system 32. As shown in Figure 2 Fig. 1, the second liquid detector 41 is arranged in the housing 22 of the apparatus 1 in the vicinity of the opening 13 of the shaft 14. According to Figure 2In an embodiment, the data processing device 34 in the node 12 is configured to also receive data from the second liquid detector 41, so that the data processing device includes executable instructions for detecting the presence state of the second flushing liquid outside the flushing liquid system through the second liquid detector 41. The data processing device includes executable instructions for determining that the second flushing liquid presence state is positive when the presence of flushing liquid outside the flushing liquid system is detected, or determining that the second flushing liquid presence state is negative when the presence of flushing liquid outside the flushing liquid system is not detected, and executable instructions for using the wireless data communication system 36 to send the second flushing liquid presence state at a second data sending interval for further processing if the second flushing liquid presence state is positive. If the second flushing liquid presence state is positive, there is a leak in the seal, and the data sending interval is at least shorter than the first data sending interval. In Figure 2 In the embodiment, the second liquid detector 41 is mechanically connected (i.e. wired) to the first liquid detector 40 in the node 12 to perform data transmission and communication with the common data processing device 34 and the wireless data communication system 36. The second liquid detector 41 may also be provided with a wireless data communication system 36, such as Figure 3 As shown, data transmission communication with the node 12 is achieved wirelessly via the wireless data communication system 36 .

[0076] The seal monitoring system 10 according to the present invention can be used for any mechanical seal of a rotatable shaft and operates by implementing at least the following steps. First, a seal 11 provided with a flushing liquid system 32 is arranged between the rotatable shaft and the stationary housing 22. The mechanical seal 11 is provided with a first liquid detector 40, and the first liquid detector 40 is configured to detect the presence of flushing liquid in the flushing liquid system 32. Figure 4 , Figure 4 A flow chart of the method according to the invention with intermittently implemented liquid detection is shown, wherein after each start-up 100 of the apparatus 1, the seal monitoring system 10 is operated by a process controlled by the execution of a computer program in the data processing device 34. First, the presence of a first flushing liquid in the flushing liquid system 32 is detected 104 by the first liquid detector 40, and then in step 108 it is concluded whether the presence of the first flushing liquid is positive or negative, i.e. whether liquid is detected.

[0077] In the case where the first flushing liquid presence state is positive Y, in step 110, the first flushing liquid presence state is sent to further processing using the wireless data communication system 36 with the first data transmission interval. Now, since there is liquid, the situation is normal, and the first data transmission interval can be set or kept quite long, or in some cases, data transmission can be omitted completely until the first flushing liquid state is detected as negative. According to one embodiment of the present invention, the first data transmission interval is greater than one hour, advantageously even greater than 4 hours. In some cases, the first data transmission interval is infinite, which means that if the first flushing liquid presence state is positive, data transmission is stopped. This process significantly reduces the energy consumption of the equipment, because only liquid detection will only consume a minimum amount of energy. Next, control returns to step 104, so that the first flushing liquid presence state in the flushing liquid system 32 is detected again.

[0078] Optionally, in order to reduce the energy consumption of the seal monitoring system, according to one embodiment of the present invention, the wireless data communication system 36 may be set to idle between each data transmission.

[0079] If the first flushing fluid presence status is concluded to be negative N in step 108, i.e., no liquid is detected, then in step 112, the first flushing fluid presence status is immediately transmitted for further processing using the wireless data communication system 36. Advantageously, in step 112, the wireless data communication system 36 is configured to transmit the first flushing fluid presence status at a second data transmission interval that is shorter than the first data transmission interval, the second data transmission interval being advantageously less than 60 seconds.

[0080] Now back Figure 3 The mechanical seal may be provided with a second liquid detector 41 (eg, Figure 2 ), but the second liquid detector 41 also includes a wireless data communication system 36, through which data generated by the data processing device 34 of the first liquid detector 40 can be sent via the node 12 for further processing, such as to a data storage device, a user console, a cloud service, etc. The second liquid detector 41 also includes a dedicated electrical energy storage device 33, such as a battery or a rechargeable battery. The energy storage device 33 provides power for operating the second liquid detector 41. The energy storage device 33 has the capacity to provide energy for operating the second liquid detector 41 for a period of several months.

[0081] The data can be used for general monitoring of the operation of the apparatus 1 or for sending process data, such as alarms, to an operator's mobile device. The second liquid detector 41 is configured to detect the presence of flushing liquid outside the flushing liquid system. The presence of a second flushing liquid outside the flushing liquid system is detected by the second liquid detector 41. If the second flushing liquid presence status is positive, the second flushing liquid presence status is used for further processing. If both the first and second flushing liquid presence statuses are positive, it is known that the mechanical seal is leaking.

[0082] The second liquid detector 41 comprises a dedicated data processing device or system, such as a microprocessor 34 or the like, which is configured to control the operation of the second liquid detector 41 and its data communication with the node 12. The second liquid detector 41 is advantageously a stand-alone device, which is advantageously provided with a dedicated power source, such as a battery or an accumulator. Figure 3 In an embodiment of the present invention, the second liquid detector is operated such that a second flushing liquid presence status outside the flushing liquid system 32 is detected by the second liquid detector 40, and if the second flushing liquid presence status is negative, the second flushing liquid presence status is transmitted for further processing using the wireless data communication system 36 with a first data transmission interval between transmissions, and if the first flushing liquid presence status is positive, the second flushing liquid presence status is transmitted for further processing using the wireless data communication system 36 with a second data transmission interval between transmissions that is shorter than the first transmission interval. The second flushing liquid presence status is transmitted for further processing via the node 12.

[0083] Figure 5 An advantageous embodiment of the invention is schematically shown, with Figure 1 Compared to the seal monitoring system 10 shown, according to this embodiment, there are additional features and elements that bring additional functionality to the device 1 and the seal monitoring system 10. Figure 5The seal monitoring system 10 of the embodiment includes: a first liquid detector 40, which is configured to detect the presence of liquid within the flushing liquid system 32; an optional second liquid detector 41, which is configured to detect the presence of liquid outside the flushing liquid system 32; and an additional vibration sensor unit 43. The first and second liquid detectors include a dedicated data processing device or system 34, such as a microprocessor, which is configured to control the operation of the first liquid detector 40 and the second liquid detector 41, respectively, and their data communication. The vibration sensor unit 43 is configured to intermittently detect vibrations and detects vibrations using a first detection interval when the first flushing liquid presence status is positive, and detects vibrations using a second detection interval that is shorter than the first detection interval when the first flushing liquid presence status is negative. The detection interval for detecting vibrations does not need to be the same as the first or second interval for detecting the first or second flushing liquid presence status.

[0084] When the seal monitoring system 10 is provided with first and second liquid detectors 40, 41, the system can be operated such that when the liquid detection system generates a positive determination of both the first flushing liquid present state and the second flushing liquid present state, it can be inferred that, for example, a dry operation has caused a seal failure. This information can be used to trigger the sending of an alarm signal.

[0085] The vibration sensor unit 43 comprises, for example, one or more acceleration sensors configured to detect vibrations of the device 1 in one or more directions. Figure 5 As shown, a second liquid detector 41 is arranged near the opening 13 of the shaft 14 arranged in the housing 22 of the machine for detecting liquid that may leak through the seal 18. A vibration sensor unit 43 is firmly attached to the body 22 of the device 1 so that the vibration of the device 1 can be determined when the device is in operation.

[0086] The seal monitoring system 10 comprises a node 12, into which a vibration sensor unit 43 is arranged in this embodiment of the invention. The node 12 is also provided with a data processing device 34 having executable instructions for controlling the operation of the node 12 so that the method defined in the accompanying method claims can be put into practice. The first liquid detector 40 and the second liquid detector 41 are configured to communicate with the node 12 for wireless data transmission. The node 12 is configured to serve as a centralized data transmission link between the first liquid detector 40 and a gateway 50 to the Internet 100, and between the second liquid detector and the gateway 50 to the Internet 100, for connecting the seal monitoring system 10 to the Internet 100 in a centralized manner. The data processing device 34 of the node 12 includes executable instructions for relaying data from the first liquid detector 40 and the second liquid detector 41 to the Internet 100 and further relaying the data to a predetermined destination for further processing.

[0087] according to Figure 5 In an embodiment, the data processing device 34 of node 12 is configured to receive data from a first liquid detector 41 and optionally a second liquid detector 41, such that the data processing device includes executable instructions for detecting the presence of a first flushing liquid within the flushing liquid system via the first liquid detector 40. In addition to detecting the presence of the first flushing liquid, the seal monitoring system 10 is configured to read and process data from a vibration sensor unit 43. The vibration signal data is used to determine whether the device 1 is operating. This can be detected using, for example, a frequency or time domain vibration signal obtained using a fast Fourier transform (FFT). According to one embodiment of the present invention, the vibration signal data is analyzed to detect a timestamp of the startup moment of the device 1, and the presence of the first flushing liquid is detected at the startup moment of the device 1. In this way, it is possible to check and / or confirm that the flushing liquid system is operating at the startup moment of the device 1.

[0088] exist Figure 5 In the disclosed seal monitoring system 10, the first liquid detector 40 is operated so that the first flushing liquid presence status in the flushing liquid system 32 is detected by the first liquid detector 40. If the first flushing liquid presence status is positive, the first flushing liquid presence status is transmitted for further processing using the wireless data communication system 36 at a first data transmission interval between transmissions, and if the first flushing liquid presence status is negative, the first flushing liquid presence status is transmitted for further processing using the wireless data communication system 36 at a second data transmission interval that is shorter than the first transmission interval. The first flushing liquid presence status is transmitted via the node 12 for further processing.

[0089] Then, the second liquid detector 41 is operated so as to detect the presence of the second rinsing liquid outside the rinsing liquid system 32 by the second liquid detector 41. If the second rinsing liquid presence status is negative, the second rinsing liquid presence status is transmitted for further processing using the wireless data communication system 36 with a first data transmission interval between transmissions, and if the first rinsing liquid presence status is positive, the second rinsing liquid presence status is transmitted for further processing using the wireless data communication system 36 with a second data transmission interval between transmissions that is shorter than the first transmission interval. The second rinsing liquid presence status is also transmitted via the node 12 for further processing.

[0090] Advantageously, the transmission interval of data (including vibration information, the first rinsing liquid presence status, and / or the second rinsing liquid presence status) from node 12 to further processing is determined by the rinsing liquid presence status as follows: when the first rinsing liquid presence status is positive or the second rinsing liquid presence status is negative, the transmission interval for the data is longer, i.e., the first transmission interval is used; and when the first rinsing liquid presence status is negative or the second rinsing liquid presence status is positive, the transmission interval for the data is shorter, i.e., the second transmission interval is used.

[0091] Even though not shown in the figure, the data processing device and the wireless data communication system 36 can also be integrated into one data processing unit. Wireless transmission devices such as Bluetooth, Wi-Fi or general radio frequency transmission devices are only examples of a few optional devices, and there is no intention to limit the present invention to the listed alternatives.

[0092] Although the present invention has been described by way of example in connection with what are presently considered to be the most preferred embodiments, it should be understood that the invention is not limited to the disclosed embodiments, but is intended to cover various combinations or modifications of its features, as well as several other applications included within the scope of the invention as defined in the appended claims. Details mentioned in connection with any of the above embodiments may be used in connection with another embodiment when such a combination is technically feasible.

Claims

1. A method of operating a seal monitoring system (10) in a seal (11) of a rotatable shaft (14), comprising a seal (11) provided with a flushing fluid system (32) between the rotatable shaft (14) and a stationary housing (22), a first liquid detector (40) configured to detect the presence of flushing fluid in the flushing fluid system (32), the method comprising: - detecting the presence of the first flushing liquid in the flushing liquid system by means of a first liquid detector (40), and a) When the presence of the first flushing liquid is confirmed, transmitting the first flushing fluid presence status for further processing using a wireless data communication system (36) with a first data transmission interval between data transmissions, and b) When the first flushing liquid presence state is negative, using a wireless data communication system (36) to transmit the first flushing fluid presence status for further processing at a second data transmission interval between data transmissions that is shorter than the first transmission interval, The first liquid detector (40) is configured to intermittently detect the presence of the flushing liquid, and the method includes detecting the first flushing liquid presence state using a first detection interval when the first flushing liquid presence state is positive, and detecting the first flushing liquid presence state using a second detection interval shorter than the first detection interval when the first flushing liquid presence state is negative. The wireless data communication system (36) is set to idle between data transmissions.

2. The method of operating a seal monitoring system (10) according to claim 1, characterized in that In step a), the first data sending interval exceeds one hour.

3. The method of operating a seal monitoring system (10) according to claim 1, characterized in that In step b), the second data sending interval is less than 60 seconds.

4. The method according to any one of the preceding claims 1 to 3, characterized in that providing the seal with a second liquid detector (41) external to the seal housing, and configuring the second liquid detector (41) to detect the presence of flushing liquid external to the flushing liquid system, and The second flushing liquid presence status outside the flushing liquid system (32) is detected by a second liquid detector (41), and when the second flushing liquid presence status is positive, the second flushing liquid presence status is sent for further processing.

5. The method according to any one of the preceding claims 1 to 3, characterized in that The seal monitoring system (10) is provided with a vibration sensor unit (43), and the method includes detecting vibration information of a shaft of the device and determining the rotation state of the shaft (14) based on the vibration information, and In step a), the vibration information is transmitted for further processing using a first data transmission interval between data transmissions, and in step b), the vibration information is transmitted for further processing using a second data transmission interval between data transmissions.

6. The method according to claim 1, characterized in that The flushing fluid system (32) includes a node (12) to which a first flushing fluid presence status is transmitted using a wireless data communication system, and the first flushing fluid presence status is transmitted from the node (12) using a wireless data communication system for further processing.

7. A seal monitoring system (10) for a seal (11) in a device, comprising a rotatable shaft (14), a flushing fluid system (32), the seal (11) being arranged between the rotatable shaft (14) and a housing (22), wherein: The seal monitoring system (10) includes a first liquid detector (40) configured to detect the presence of flushing liquid in the flushing liquid system (32), a data processing device (34) configured to receive data from the first liquid detector (40), and a wireless data communication (36) system connected to the data processing device (34) for data transmission, and wherein, The data processing device (34) comprises: - executable instructions for detecting the presence of a first flushing fluid in the flushing fluid system (32), - executable instructions for determining a first flushing liquid presence status as positive when flushing liquid is detected in the flushing liquid system, or determining a first flushing liquid presence status as negative when flushing liquid is not detected in the flushing liquid system, Characterized in that the data processing device (34) further comprises: - using the wireless data communication system (36) to transmit the first flushing fluid presence status at a first data transmission interval for further processing when the flushing fluid presence status is positive, and - executable instructions for transmitting the first flushing liquid presence status for further processing using a wireless data communication system (36) at a second data transmission interval shorter than the first transmission interval between data transmissions if the flushing liquid presence status is negative, the first liquid detector (40) being configured to intermittently detect the presence of flushing liquid, and the data processing device (34) including executable instructions for detecting the first flushing liquid presence status using a first detection interval if the first flushing liquid presence status is positive, and executable instructions for detecting the first flushing liquid presence status using a second detection interval shorter than the first detection interval if the first flushing liquid presence status is negative, The data processing device (34) includes executable instructions for idling the wireless data communication system (36) between data transmissions.

8. The seal monitoring system according to claim 7, characterized in that The data processing device (34) includes executable instructions for transmitting the first flushing fluid presence status for further processing using a wireless data communication system (36) at a first data transmission interval exceeding one hour if the flushing fluid presence status is positive.

9. The seal monitoring system according to claim 7, characterized in that: The data processing device (34) includes an executable instruction for setting the second data transmission interval to be less than 60 seconds.

10. The seal monitoring system (10) according to claim 7, characterized in that The seal monitoring system (10) includes a node (12) configured to communicate with a gateway (50) to the Internet, and the first liquid detector (40) is configured to communicate with the node (12).

11. The seal monitoring system (10) according to claim 10, characterized in that The seal monitoring system (10) includes a second liquid detector (41) configured to detect the presence of liquid outside the flushing liquid system (32), and the second liquid detector (41) is configured to communicate with the node (12), and the node (12) is configured to communicate with a gateway (50) to the Internet and transmit data obtained by the first liquid detector (40) and the second liquid detector (41) to the gateway (50).

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