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WO2004076075A1 - Detection d'ecoulement dans des systemes d'application de liquide - Google Patents

Detection d'ecoulement dans des systemes d'application de liquide Download PDF

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Publication number
WO2004076075A1
WO2004076075A1 PCT/US2004/006024 US2004006024W WO2004076075A1 WO 2004076075 A1 WO2004076075 A1 WO 2004076075A1 US 2004006024 W US2004006024 W US 2004006024W WO 2004076075 A1 WO2004076075 A1 WO 2004076075A1
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WO
WIPO (PCT)
Prior art keywords
nozzle
signal
flow
liquid
sensor
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/US2004/006024
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English (en)
Inventor
James M. Khoury
Andrew E. Prutton
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Nordson Corp
Original Assignee
Nordson Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Nordson Corp filed Critical Nordson Corp
Publication of WO2004076075A1 publication Critical patent/WO2004076075A1/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
    • B05B12/00—Arrangements for controlling delivery; Arrangements for controlling the spray area
    • B05B12/08—Arrangements for controlling delivery; Arrangements for controlling the spray area responsive to condition of liquid or other fluent material to be discharged, of ambient medium or of target ; responsive to condition of spray devices or of supply means, e.g. pipes, pumps or their drive means
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
    • B05B15/00—Details of spraying plant or spraying apparatus not otherwise provided for; Accessories
    • B05B15/14—Arrangements for preventing or controlling structural damage to spraying apparatus or its outlets, e.g. for breaking at desired places; Arrangements for handling or replacing damaged parts
    • B05B15/18—Arrangements for preventing or controlling structural damage to spraying apparatus or its outlets, e.g. for breaking at desired places; Arrangements for handling or replacing damaged parts for improving resistance to wear, e.g. inserts or coatings; for indicating wear; for handling or replacing worn parts
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
    • B05B15/00—Details of spraying plant or spraying apparatus not otherwise provided for; Accessories
    • B05B15/50—Arrangements for cleaning; Arrangements for preventing deposits, drying-out or blockage; Arrangements for detecting improper discharge caused by the presence of foreign matter

Definitions

  • the invention relates generally to apparatus and methods for applying liquid and liquefiable material onto a surface. More particularly, the invention relates to detecting abnormal flow conditions including substantially no-flow conditions within the liquid application device.
  • a typical application device includes a nozzle assembly having an orifice through which the liquid material is ejected in a pattern.
  • a typical nozzle assembly may include a nozzle body or cap, a nozzle tip with the orifice therein, and a nut or other device that is used to attach the nozzle assembly to the gun body.
  • a valve mechanism is also commonly used within the nozzle assembly, with the valve mechanism being open and closed in response to a signal from an operator or controller.
  • a controller may issue a trigger signal that indicates whether the valve should be open or closed.
  • a nozzle may be of a multi-piece construction or an integral device. In many gun designs, the nozzle assembly is designed to atomize the liquid to improve the quality of the film or coating applied to an article. Electrostatic energy may also be used to electrostatically charge the liquid pattern. There are many different types of guns and nozzles and the present invention is not limited to any particular type or configuration or application technology, including but not limited to spraying, dispensing, electrostatic, non- electrostatic, air assisted and so on.
  • the invention contemplates in one aspect method and apparatus for detecting or monitoring liquid flow conditions in a liquid application device.
  • Such flow conditions may be normal or abnormal depending on the condition of the liquid application equipment.
  • An abnormal flow condition is broadly understood as any flow condition that is higher or lower than a selectable limit.
  • the detected flow condition is the presence or absence of desired flow through a nozzle assembly that is associated with the liquid application equipment such as, for example, a spray gun or dispensing gun.
  • an abnormal flow condition may be the complete absence or attenuation of flow through a totally or partially clogged nozzle assembly.
  • the invention will find application in other flow elements wherein liquid flow causes mechanical radiant energy that can be detected.
  • normal and abnormal flow conditions are detected by positioning a sensor external the nozzle assembly.
  • the external sensor detects mechanical radiant energy produced by liquid flow through the nozzle assembly, such as vibration transmitted through the nozzle assembly.
  • an accelerometer assembly is disposed in intimate contact on an outer surface of a nozzle assembly so as to detect vibration caused by atomization of liquid within the nozzle assembly. The absence of vibration energy is detected as an abnormal flow condition, thus indicating a clogged or worn nozzle that may be resulting in poor or unacceptable coatings.
  • a sensor circuit includes several optional functions that relate to detecting vibration energy produced by liquid flow in a nozzle assembly.
  • the sensor circuit may optionally be used to determine gun on delay, gun off delay, gun on duration, and flow/no flow or low flow conditions.
  • the sensor circuit may also optionally include a band pass filter to reduce noise effects from other vibration causing elements in the liquid application system, such as for example, pumps and other guns.
  • the sensor circuit may further optionally include a de-bounce function in which an abnormal flow alarm or indication is made after a predetermined number of abnormal flow conditions have been detected.
  • the sensor circuit may also optionally determine average signals from the sensor, and may select and store the last detected signal from the sensor just prior to the gun trigger signal turning off the spraying operation.
  • the invention further contemplates the methods embodied in the use of such apparatus as set forth above, as well as a method for detecting normal and abnormal flow conditions in a liquid application device, comprising the steps of producing a control signal that controls flow of material through the device, detecting mechanical radiant energy produced by flow of liquid through the device, the radiant energy being transmitted through the device, and determining normal and abnormal flow conditions based on the detected radiant energy as a function of the control signal, hi some applications, use of the control signal as part of the flow condition determining step may be optional.
  • FIG. 1 is a schematic representation of a material application system that incorporates the invention.
  • Fig. 2 is a spray nozzle with a sensor mounted exteriorly thereof, shown in longitudinal cross-section;
  • Fig. 3 is a functional block diagram of a conditioning circuit and an analytical circuit suitable for use with the present invention
  • Fig. 4 is a detailed schematic diagram of an exemplary conditioning circuit suitable for use with the present invention
  • Fig. 5 is an exemplary Bode plot for an exemplary band pass filter circuit suitable for use with the present invention
  • Fig. 6 is a scope trace of a typical sensor output signal after converting the signal from ac to RMS dc;
  • Fig. 7 is a timing diagram showing an exemplary data sampling technique suitable for use with the invention.
  • the present invention provides among other things as described herein methods and apparatus for detecting liquid flow through a device.
  • a liquid spraying device such as a spray gun
  • Such systems include but are not limited to electrostatic and non- electrostatic systems, air assisted atomization and pressure atomization systems, as well as liquid application systems that do not necessarily atomize the liquid, and liquid application systems that are manually operated or electronically controlled automatically.
  • liquid as used herein is intended to be interpreted in its broadest sense to include not only homogenous liquids but also any liquefiable material such as suspensions, slurries, epoxies and so.
  • liquid flow in a device such as a spray nozzle of a liquid spray gun to name one example, may be sufficiently turbulent to produce mechanical radiant energy that is transmitted as longitudinal pressure waves in a material medium. These longitudinal pressure waves cause vibrations in the spray nozzle.
  • mechanical radiant energy includes vibrations as one example and it is within the scope of this invention to sense such vibrations and relate them to a liquid flow condition.
  • this mechanical radiant energy could be manifested as sound waves which may be but need not be within an audible range of humans. Therefore, it is also within the scope of this invention to sense such sound waves with a sound wave sensing device and relate them with a liquid flow condition. Due to inherent ambient noise such as sound waves that transmit through air, however, the exemplary embodiments of the invention are directed to detecting such mechanical radiant energy transmitted through a material medium such as a gun body part (for example, a spray nozzle) as vibrations rather than as sound waves. Regardless of the form of the mechanical radiant energy sensed, the present invention is not limited in use to any particular liquid flow device such as a liquid spray nozzle. 2. DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION
  • a material application system 10 in accordance with an exemplary embodiment of the invention is illustrated in a simplified schematic form.
  • liquid application device 12 such as a liquid spray gun.
  • a suitable gun is a model A7A available from Nordson Corporation, Westlake, Ohio, however, any liquid application device may be used and need not be limited to spray and dispensing guns.
  • the application device 12 typically includes a nozzle assembly 14 having a nozzle tip 16 that defines an outlet or orifice 18 through which liquid material is ejected, sprayed or dispensed.
  • a sensor 20 that detects mechanical radiant energy resulting from fluid flow within the nozzle assembly 14 and produces a corresponding output signal 22.
  • the output signal 22 typically will be an AC electrical output signal, although other signal formats may be used such as optical, RF, TR and so on depending on the design of the selected sensor 20 and related circuitry.
  • a sensor 20 is disposed with respect to the application device 12 (in this case on the nozzle assembly 14) so as to be able to detect mechanical radiant energy caused by the turbulent flow of liquid within the nozzle assembly 14.
  • Such turbulence may arise from the liquid being under pressure as it is being forced out the orifice 18, as well as the composition of the liquid, and furthermore some devices 12 include turbulence plates to increase such turbulence.
  • the sensor 20 detects mechanical radiant energy, such as for example vibrations, transmitted through the nozzle assembly, and produces the output signal 22 in relation thereto.
  • the sensor 20 preferably although not necessarily is mounted on a surface of the nozzle assembly 14.
  • the sensor 20 may be positioned anywhere that it is able to detect the mechanical radiant energy of interest.
  • the sensor 20 can be disposed off of the nozzle 14 or the device 12 provided that there is adequate coupling of the mechanical energy to the sensor 20.
  • the sensor 20 in one embodiment is a thin film piezoelectric accelerometer, model ACH-01 available from Measurement Specialties Incorporated, Norristown, PA.
  • Such a device includes a housing that is mounted with a suitable adhesive to the surface of interest, such that the vibration sensitive element itself is not directly in contact with the mounting surface.
  • a significant advantage of the present invention is that it permits detection of flow conditions completely exterior of the flow device. This is a non-intrusive sensing technique that avoids if so desired any need to modify the liquid application device, or any portion of the internal flow path of the liquid being applied.
  • the exemplary embodiments illustrate the use of a vibration sensor 20, other mechanical radiant energy sensors may be used in the alternative.
  • One example would be a microphone that could be used to detect sound waves transmitted through air.
  • the vibration sensor 20 is preferred as there is usually substantial ambient noise that would need to be filtered out from the sensor signal in order to detect the signal component that related to the liquid flow.
  • noise cancelling techniques may be used as required.
  • the exemplary embodiments herein use time domain noise filtering.
  • frequency domain filtering For example, if there is a known source of noise in the sensor output within specific frequency ranges, suitable processing, particularly digital, may be used to filter such noise.
  • DSP digital signal processing
  • Another option would be to use differential noise cancellation in which a second sensor may be appropriately positioned relative to the primary sensor 20 so as to detect noise components that are present in the sensor 20 output. By subtracting the two sensor outputs from each other, the noise is substantially filtered leaving a stronger signal to noise ratio in the filtered sensor output.
  • DSP digital signal processing
  • the sensor 20 thus produces an output signal 22 that corresponds to the liquid flow characteristics inside the flow device 14 of interest, in this case a spray nozzle.
  • the presence of detected mechanical radiant energy corresponds to a normal flow condition if the output signal 22 meets predeterminable criteria, and the absence of such mechanical radiant energy would correspond to an abnormal flow condition such as might arise, for example, from a worn or clogged nozzle.
  • a conditioning circuit 24 may be used to carry out one or more functions such as a preamplifier to strengthen the sensor output signal, and a band pass filter function to reduce low frequency noise that may be present in the sensor 20 signal. Still further a line driver function may be used to allow the sensor signal to be coupled over a long cable distance to a processing circuit. Such coupling may be necessary, for example, to meet various fire safety regulations.
  • the output 110 of the conditioning circuit 24, or if appropriate the output of the sensor 20, may be input to an analytical sensor circuit 26.
  • the analytical circuit 26 may be used to carry out one or more functions for interpreting the sensor 20 output signal 22.
  • the analytical circuit 26 may be used to detect any one or more of the gun on delay time, gun off delay time, gun on duration time, actuation of the internal control valve of the nozzle assembly
  • the analytical circuit 26 may also perform a calibration function as will be described hereinafter.
  • Typical liquid application systems are controlled by means of a device controller 28.
  • This controller 28 may perform a wide variety of functions, one of which is to produce a flow control signal 30 that is sent to the application device 12, usually in the form of a trigger signal.
  • the trigger signal controls operation of a spray on/off valve in the device 12.
  • This is one example of a convenient signal that may be used by the analytical circuit 26, as represented by the additional signal line input thereto in Fig. 1.
  • a corresponding trigger signal may be generated in response to actuation of the gun trigger and supplied to the analytical circuit 26. It is important to note that use of the control signal 30 is not required in all embodiments of the invention.
  • circuits 24, 26 and 28 may be realized in a wide variety of ways well known to those skilled in the art.
  • the circuits may be digital, analog or a combination thereof. They may include programmable controllers such as microprocessor based systems as well as circuits built from discrete components, programmable logic controllers, state machines and so on.
  • the invention is not limited in any manner to the design and implementation of the various circuits described herein.
  • the circuits may be combined into a single circuit arrangement, or may be realized as separate circuits.
  • a liquid application device in the form of a spray gun head 40 and nozzle assembly 42 is shown.
  • reference numeral 42 corresponds to the same element as numeral 14 in Fig. 1
  • reference numeral 46 corresponds to the same element as numeral 16 in Fig. 1.
  • This spray gun head and nozzle functions may be but need not be substantially as described in the following United States Patents: 3,702,107 issued to Rood et al., the entire disclosure of which is fully incorporated herein by reference.
  • the gun head 40 is mounted on a gun body (not shown) which supplies liquid material to the head. Operation of the spray gun is not important to an understanding of the present invention and reference may be made to the referenced patents for additional detail.
  • liquid material under pressure enters the gun head 40, passes into a nozzle cap 44 and exits through a nozzle tip 46 having an orifice 18 therein.
  • a nut 48 is used to secure the nozzle cap 44 onto the gun head 40.
  • the present invention may be used with a wide variety of gun and nozzle designs, as well as with other fluid carrying devices. Due to the constricted flow through the orifice 18, a substantial turbulence is produced inside the nozzle cap 44 under normal flow conditions. This turbulence produces mechanical radiant energy that is transmitted through the structure of the nozzle cap 44 and also may transmit through the gun head 40. This mechanical energy, most notably in the form of vibrations, is further transmitted in and through the nut 48.
  • the senor 20 is mounted against the nut 48.
  • the sensor is realized in the form of a thin film piezoelectric accelerometer 50 that is embedded in an epoxy fill 52 within a housing 54.
  • the housing 54 is securely mounted on the nut 48 using a set screw or bolt 56.
  • the mounting of the sensor is done in a close coupled manner so as to provide sufficient mechanical acoustic coupling between the sensor 50 and the nut 48 so as to minimize attenuation of the mechanical radiant energy produced by the liquid.
  • Suitable alternative mounting arrangements will be readily apparent to those skilled in the art and are determined in large measure by the structure of the particular flow device being monitored.
  • liquid flow is controlled by opening and closing a valve that is realized in the form of a ball valve element 60 that engages a valve seat 62 to close the valve.
  • a valve stem 64 under the control of an actuator (not shown) pulls the ball 60 away from the seat to open the valve and permit flow through the nozzle.
  • the valve actuation may be controlled by the flow control signal 30 (Fig. 1) to the actuator.
  • the sensor output signal by itself contains enough information to determine flow conditions within the flow device 12. Therefore, the various circuits described herein, although preferred, are not required and are optional depending on a specific application.
  • the sensor 20 output signal 22 is input to a preamplifier circuit which may be conventional in design to provide gain.
  • a fixed gain circuit may be used when the invention will be used with similar fluid application devices.
  • the quality and signal to noise ratio of the sensor output 22 is a function of a number of factors including the pressure of the liquid, the characteristics of the liquid, the quality of the coupling between the sensor and the flow device, and so on. Consequently, in some applications it will be advantageous to utilize a variable gain preamplifier circuit so that the gain can be adjusted to provide the best signal to noise ratio of the conditioned signal.
  • the preamplifier is designed as a conventional circuit so as to boost the signal strength so that the conditioned signal can be transmitted down a long cable if needed for fire protection regulations.
  • the preamplifier 100 may be designed as a high input impedance amplifier to minimize the load on the sensor 20 and noise effects.
  • the conditioning circuit also provides bias current for sensor excitation (+V in Fig. 4).
  • the preamplifier output 102 is input to a band pass filter 104.
  • the band pass filter 104 may be conventional in design and based on the particular application for the invention. For example, for the exemplary embodiment herein we have discovered that liquid paint under normal flow and atomization conditions produces a strong vibration frequency at around 10 kHz.
  • the band pass filter in this example is designed to pass signals in that frequency range.
  • the band pass filter 104 may be designed to attenuate low frequency noise. For example, operation of the spray gun and surrounding equipment can inject low frequency vibration into the system.
  • the output 106 of the band pass filter 104 is input to a line driver 108.
  • the line driver 108 The line driver
  • the output 110 of the line driver 108 is input to the analytical circuit 26.
  • Fig. 4 provides an exemplary embodiment of the conditioning circuit 24.
  • Each of the functional blocks of Fig. 3 is identified by dashed boxes. Again, these circuit concepts are conventional and subject to many iterations and variations depending on the particular application system.
  • Fig. 5 is a Bode plot of amplitude versus frequency (logarithmic scale) of an exemplary band pass filter 104. Note that the frequency response is fairly flat in the region 104a from about 3 KHz to about 80 KHz, with an upper roll off around 100 KHz. Further note the attenuation in the region 104b from about 10 Hz to about 1 KHz. This attenuation removes noise present in the sensor output 22 that is not related to vibration from the liquid material flow condition.
  • the particular frequency response may be selected based on the overall system design, and in some cases the band pass filter, the preamplifier and/or the line driver circuit may be omitted.
  • the conditioning circuit 26 may be realized in many different forms and configurations.
  • the circuit is microprocessor based but such a design is not required.
  • the conditioning circuit 24, the analytical circuit 26 and the control circuit 28 may be combined into a single circuit, or incorporated into another control circuit, or may be separately provided in different sub- combinations.
  • a detailed schematic of the analytical circuit is not necessary to understand and practice the present invention since microprocessor based control systems are well known and readily available to execute the functions described herein.
  • the output 110 from the line driver 108 may first be input to an intrinsic safety barrier circuit 120 for applications requiring such protection.
  • the basic characteristics of the sensor 20 output signal is at this point still an ac signal 122.
  • This signal 122 is input to an AC to DC converter circuit 124 using a Root Mean Square (RMS) method which may be of conventional design well known to those skilled in the art.
  • the output 126 of the converter 124 is a DC signal with some noise riding on top of the DC.
  • Typical wave forms are illustrated in Fig. 6 for normal flow conditions.
  • trace A is the trigger signal (30) used to control flow of liquid through the nozzle.
  • Trace B is the sensor output 22 as conditioned and after conversion from AC to DC and scaling (output 129 of Fig. 3 is represented in an exemplary manner in Fig. 6).
  • Note that the waveform follows the general shape of the trigger signal except for time delays.
  • the rising edge Al of the trigger signal corresponds in this example to a gun on command, and the falling edge
  • A2 corresponds to a gun off command.
  • the sensor output trace B note that there is a leading pulse or spike Bl, which corresponds to the ball valve element being pulled away from the valve seat. This action causes vibrational noise either from the valve actuation itself or the initial flow of liquid or both possibly.
  • Bl leading pulse or spike Bl
  • the DC value of the sensor signal substantially increased due to detecting the mechanical radiant energy of the flowing liquid.
  • the DC signal level as at Cl and C2 is low.
  • gun on delay This is a well known phenomena and referred to commonly as gun on delay.
  • gun off time There is a delay from the trigger off time A2 and the time that flow stops B2, commonly known as gun off time.
  • the time period between Bl and B2 is generally known as gun on duration which corresponds to the actual time period that liquid is being sprayed or dispensed from the gun.
  • the sensor output 22 thus in and of itself contains enough information to determine gun on duration and flow condition characteristics.
  • a worn or clogged nozzle, for example, would be noted in that the signal strength between Bl and B2 would be detectably attenuated.
  • the output 126 of the converter circuit 124 may be input to an optional and conventional scaling amplifier 128 which is used, as required, to condition and scale the DC signal as appropriate so that it can be input to an analog to digital converter 130.
  • the A/D converter 130 is used to transform the time variant signal into a pure digital output signal 131 for analysis by the microprocessor 132.
  • the microprocessor 132 in this embodiment is programmed to obtain sample values of the sensor output signal, as conditioned by the conditioning circuit 24 and the converter circuit 124 and scaling amplifier 128.
  • the microprocessor 132 periodically samples the sensor signal amplitude as represented by the output of the A D converter 130. For example, every 100 milliseconds or so the microprocessor can be programmed to obtain samples.
  • the microprocessor 132 takes ten samples for example, ignores the highest and lowest values, and averages the remaining eight samples to provide an average sample value.
  • the microprocessor may obtain two or three or more valid averaged samples.
  • the microprocessor uses the last valid averaged sample that was obtained prior to the trigger signal "off command to determine whether flow conditions are normal or abnormal (note in Fig. 3 the trigger signal 30 is shown as an input to the microprocessor 132).
  • the trigger signal 30 is shown as an input to the microprocessor 132).
  • other or different samples may be used as required in a particular system. If the selected last averaged sample value is outside a predetermined range that is assigned for "normal" flow detected vibration, then the microprocessor has detected an abnormal flow condition.
  • the microprocessor 132 can immediately issue a fault indication 134 (such as lighting a lamp or an audible signal for example) when such an occurrence is detected.
  • a de- bounce feature may be incorporated by requiring a predetermined number or percentage of consecutive averaged samples to be outside the "normal" range before a fault indication 136 is effected such as an alarm, for example, which may be used to shut down the line to stop improper application of the liquid. Using this technique can eliminate transitory noise such as from the valve opening and from pump wink.
  • Selecting the range of values for the average samples may be done empirically and stored in the microprocessor memory.
  • the microprocessor can be programmed to execute a calibration operation. During calibration, a known good nozzle is used with a known good or normal flow condition and product coating. The microprocessor takes the average samples and stores these samples or their average values or their high and low readings for example. The samples can be taken for example during a sampling time when normal flow is occurring so as to not have transient effects reflected in the calibration values. These calibrated values can then be used as a comparison of average samples taken during liquid application cycles.
  • Fig. 7 illustrates the exemplary sampling feature of this embodiment. It should be noted that any sampling technique may be used but we have found this one is particularly useful with the exemplary spray gun lags.
  • the samples may be timed with the trigger signal 30. Average samples are taken during both the gun on time period and the gun off time period, particularly during calibration. As noted in the drawing, it is the last valid averaged sample (X and Y) that is used by the microprocessor to determine if the flow condition is "normal” or within a prescribed range of values for the sensor signal, or "abnormal" meaning outside the prescribed range of values. Note from Fig. 7 that calibration can be based on a selected number of spray cycles such as four.
  • the prescribed range of values may be determined during calibration or can be determined by a separate evaluation. For example, the range of values may be set to 50% and 100% of the averaged readings across a prescribed number of cycles during calibration with normal flow conditions, steady state flow and so on.
  • the exact limits will be determined for each particular system.
  • the requested gun on time signal 30 does not match the actual gun on time or true spray duration.
  • True spray duration is a key factor in dispensing liquid materials. It determines the actual amount that liquid is dispensed (flow rate X time).
  • the true gun on and off times often are not known in many applications.
  • the gun lags can be caused by air hose length, spring k factor, air pressure, material pressure and so on.
  • the present invention allows one to measure these times and display them for operator setup and/or present fault indications based on them.

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Abstract

L'invention concerne un procédé et un appareil permettant de détecter des conditions d'écoulement normales et anormales dans un dispositif d'écoulement de liquide tel qu'une buse de pulvérisation. Des conditions d'écoulement sont détectées au moyen d'un capteur disposé à l'extérieur du dispositif d'écoulement. Ce capteur, qui peut se présenter sous la forme d'un accéléromètre piézoélectrique, détecte l'énergie de rayonnement mécanique produite par l'écoulement de liquide. L'appareil selon l'invention comprend éventuellement différents circuits servant à effectuer diverses fonctions, par exemple à détecter des conditions d'écoulement normales et anormales, émettre des signaux d'alerte et d'avertissement ou à détecter un retard d'activation de pistolet, un retard de désactivation de pistolet, une durée d'activation de pistolet, des événements de soupape tels que l'ouverture ou la fermeture, etc. Cette invention concerne en outre une technique utilisant les derniers échantillons moyens valables pour améliorer le degré de précision, ainsi qu'une caractéristique d'antirebond. L'invention se rapporte par ailleurs à différentes techniques de filtrage du bruit.
PCT/US2004/006024 2003-02-27 2004-02-27 Detection d'ecoulement dans des systemes d'application de liquide Ceased WO2004076075A1 (fr)

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US45048103P 2003-02-27 2003-02-27
US60/450,481 2003-02-27
US45392603P 2003-03-12 2003-03-12
US60/453,926 2003-03-12

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Cited By (6)

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Publication number Priority date Publication date Assignee Title
EP2184603A1 (fr) 2008-11-06 2010-05-12 Logomat S.R.L. Dispositif de test et de commande pour atomiseurs
CN102494906A (zh) * 2011-11-14 2012-06-13 北京农业信息技术研究中心 一种风送喷雾测试装置
EP3441186A1 (fr) * 2017-08-08 2019-02-13 D.E.C.O. Nv Dispositif a jet d'eau avec capteur de débit et procédé pour le découpage au jet d'eau
CN109475893A (zh) * 2016-07-28 2019-03-15 里弗雷克特里知识产权两合公司 具有喷嘴单元的系统和喷射无机质团的方法
LU100936B1 (en) * 2018-09-26 2020-03-27 Univ Luxembourg Wear monitoring device and process for an abrasive waterjet cutting head
LU101065B1 (en) * 2018-12-21 2020-06-24 Univ Luxembourg Machining system and monitoring method

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US4734681A (en) * 1985-11-13 1988-03-29 Fuji Seiki Machine Works, Ltd. Sensor for detecting condition in slurry transport line of wet blasting apparatus
US4905897A (en) * 1988-06-17 1990-03-06 Ramon Barry Rogers Field sprayer nozzle pattern monitor
WO1992020456A1 (fr) * 1991-05-17 1992-11-26 Ingersoll-Rand Company Detecteur d'integrite pour ajutage de jet de fluide
US6230986B1 (en) * 1999-01-11 2001-05-15 Itw Surfaces And Finitions Spray head for paint and similar substances

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* Cited by examiner, † Cited by third party
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FR2529808A1 (fr) * 1982-07-08 1984-01-13 Renault Procede et dispositif de detection automatique de fonctionnement anormal d'un pistolet de peinture
US4734681A (en) * 1985-11-13 1988-03-29 Fuji Seiki Machine Works, Ltd. Sensor for detecting condition in slurry transport line of wet blasting apparatus
US4905897A (en) * 1988-06-17 1990-03-06 Ramon Barry Rogers Field sprayer nozzle pattern monitor
WO1992020456A1 (fr) * 1991-05-17 1992-11-26 Ingersoll-Rand Company Detecteur d'integrite pour ajutage de jet de fluide
US6230986B1 (en) * 1999-01-11 2001-05-15 Itw Surfaces And Finitions Spray head for paint and similar substances

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EP2184603A1 (fr) 2008-11-06 2010-05-12 Logomat S.R.L. Dispositif de test et de commande pour atomiseurs
CN102494906A (zh) * 2011-11-14 2012-06-13 北京农业信息技术研究中心 一种风送喷雾测试装置
CN109475893A (zh) * 2016-07-28 2019-03-15 里弗雷克特里知识产权两合公司 具有喷嘴单元的系统和喷射无机质团的方法
US11642685B2 (en) 2016-07-28 2023-05-09 Refractory Intellectual Property Gmbh & Co. Kg System with a spraying nozzle unit and method for spraying an inorganic mass
EP3441186A1 (fr) * 2017-08-08 2019-02-13 D.E.C.O. Nv Dispositif a jet d'eau avec capteur de débit et procédé pour le découpage au jet d'eau
LU100936B1 (en) * 2018-09-26 2020-03-27 Univ Luxembourg Wear monitoring device and process for an abrasive waterjet cutting head
WO2020064974A1 (fr) * 2018-09-26 2020-04-02 Université Du Luxembourg Système de coupe à jet d'eau abrasif, buse pour un tel système et procédé de surveillance pour un tel système de coupe à jet d'eau abrasif
LU101065B1 (en) * 2018-12-21 2020-06-24 Univ Luxembourg Machining system and monitoring method
WO2020128090A1 (fr) * 2018-12-21 2020-06-25 Université Du Luxembourg Système d'usinage et procédé de surveillance
US11801579B2 (en) 2018-12-21 2023-10-31 Université Du Luxembourg Machining system and monitoring method

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