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CN-116329189-A - Cleaning device for cleaning an outer part of a sensor

CN116329189ACN 116329189 ACN116329189 ACN 116329189ACN-116329189-A

Abstract

A cleaning device for cleaning an outer part of a sensor is described, having: a pump connected on the input side to a supply line formed as an air supply line; an accumulator which is connected to the pump on the output side and can be mounted or installed on the housing of the cleaning device and arranged on the sensor; and a discharge air duct equipped with a pressure control valve, connected to the accumulator and connected or connectable to at least one nozzle, which is aligned or alignable on said outer portion to be cleaned. The cleaning device is designed to perform a pressure surge cleaning operation in which air pumped by means of a pump is compressed in an accumulator and, when the pressure exerted by the compressed air enclosed in the accumulator exceeds the pressure value required to open a pressure control valve, the compressed air generated in the accumulator is injected in the form of pressure surge via a nozzle connected to a discharge air duct.

Inventors

  • MEIER HANS
  • VACA TORRES ALEJANDRO
  • BUCHFINK MARVIN

Assignees

  • ENDRESS HAUSER CONDUCTA GMBH CO KG

Dates

Publication Date
20230627
Application Date
20221214
Priority Date
20211215

Claims (16)

  1. 1. A cleaning device (1) for cleaning an outer portion (3) of a sensor (5), the outer portion (3) of the sensor (5) being in contact with a medium during a measurement mode for measuring a measurement variable of the medium, the cleaning device (1) comprising: a pump (19), which pump (19) is connected on the input side to a supply line (21) designed as an air supply line, An accumulator (27), the accumulator (27) being connected to the pump (19) on the output side and being arranged in a housing (25) of the cleaning device (1), the housing (25) being mounted or mountable on the sensor (5), and -a discharge air duct (31), said discharge air duct (31) being equipped with a pressure control valve (29) or a pressure control valve (29) designed as a check valve and being connected to said accumulator (27) and to or connectable to at least one nozzle (33), said nozzle (33) being aligned or alignable on said outer part (3) to be cleaned, wherein the cleaning devices (1) are designed to perform cleaning processes, each comprising at least one pressure impulse fluctuation cleaning in which air sucked in via the supply line (21) by means of the pump (19) is compressed in the accumulator (27), and at least a part of the compressed air generated in the accumulator (27) is injected in the form of pressure impulse fluctuations via the nozzle (33) connected to the discharge air duct (31) when the pressure exerted by the compressed air enclosed in the accumulator (27) exceeds the pressure value required to open the pressure control valve (29).
  2. 2. The cleaning device of claim 1, wherein: the pump (19) and the pressure accumulator (27) are arranged in the housing (25) of the cleaning device (1) and/or The cleaning device (1) is designed as a component of a measuring device comprising the sensor (5) and the cleaning device (1), or as a device which can be mounted on the sensor (5) and comprises at least one of the nozzles (33) and/or the exhaust air duct (31), the exhaust air duct (31) being connectable to any nozzle (33) which forms a component of the sensor (5).
  3. 3. The cleaning device (1) according to claim 1, comprising: at least one extension (87), the at least one extension (87) being integrally molded on the housing (25), the nozzle (33) or at least one of the nozzles (33) being arranged in the extension (87), or -two extensions (87), the two extensions (87) being integrally molded on opposite sides of the housing (25) of the cleaning device or on opposite sides of the housing (25) of the cleaning device when the cleaning device (1) is connected to the sensor (5), the two extensions (87) surrounding at least a part of the sensor (5) on the outside on opposite sides of the housing (25), wherein at least one of the nozzles (33) is arranged in at least one of the two extensions (87).
  4. 4. A cleaning device (1) according to claims 1 to 3, further comprising a wiper drive, an electric wiper drive or a pneumatic wiper drive, and comprising a wiper (35), by means of which wiper drive the wiper (35) is operable for performing wiping cleaning of the outer part (3).
  5. 5. Cleaning device (1) according to claim 4, the cleaning device (1) being designed such that each cleaning process comprises at least one pressure impulse fluctuation cleaning and ends with a wiper cleaning performed by means of the wiper (35).
  6. 6. A cleaning device (1) according to claims 4 to 5, wherein: the wiper drive comprises a piston (45) arranged in a piston housing (43), wherein a first chamber (51) and a second chamber (53) are located in the piston housing (43), the second chamber (53) being separated from the first chamber (51) by the piston (45), the piston (45) is connected to the shaft (39) of the wiper (35) via a mechanical transducer (55) such that a movement of the piston (45) from a first end position, in which the piston (45) abuts against a first stop (47), to a second end position, in which the piston (45) abuts against a second stop (49) opposite the first stop (47), causes a rotational movement of the wiper arm (41) corresponding to the movement from the start position to the end position, the first stop (47) delimiting the first chamber (51) on a side facing away from the second chamber (53), the second end position being such that the piston (45) abuts against the second stop (49) The pump (19) is connected to an inlet (61) of the piston housing (43), the inlet (61) opening into the first chamber (51) via a discharge line (23) connected to the pump (19) at the output side.
  7. 7. The cleaning device (1) according to claim 6, wherein the first chamber (51) forms the accumulator (27), and the cleaning device (1) is designed such that the pressure control valve (29) is opened by the pressure present in the first chamber (51) when the piston (45) moved by the pressure present in the first chamber (51) reaches the second end position.
  8. 8. A cleaning device (1) according to claims 6 to 7, wherein: the exhaust air duct (31) in the piston housing (43) opens into a cutout (62) that opens into the interior of the piston housing (43), or into a cutout (62) formed by a branching passage that extends through a portion of a bore of the piston housing (43) or around the interior of the piston housing (43), and the cutout (62) is arranged at a height within the piston housing (43) which is dimensioned such that a lower edge of the cutout (62) facing the second stop (49) abuts an upper side of the piston (45) facing an outer edge of the first chamber (51) when the piston (45) is in the second end position.
  9. 9. Cleaning device (1) according to claims 6 to 8, comprising a spring (63), a spring (63) designed as a compression spring in the second chamber (53), a spring designed as an extension spring in the first chamber (51), or a spring arranged outside the piston housing (43) and/or connected to a spindle (57) of the converter (55) or the wiper (35), wherein the spring (63) comprises at least one spring element, at least one spring element as a compression spring element, a clamping spring element, a helical spring element or a diaphragm designed as a spring element, or a plurality of coupled spring elements, and wherein the spring (63) is designed such that the spring (63) is tensioned by the piston (45) moving from the first end position to the second end position, and the piston (45) is moved back to the first end position by the spring force of the tensioned spring (63) when the pressure in the first chamber (51) drops due to pressure surge output via the pressure control valve (29).
  10. 10. The cleaning device (1) according to claims 6 to 9, comprising a gas supply regulator (73), the gas supply regulator (73) being designed to temporarily close and subsequently reopen the inlet (61) to the first chamber (51) during each pressure-surge cleaning performed with the cleaning device (1), or Comprising a gas supply regulator (73), the gas supply regulator (73) comprising a gate valve (75) and a return spring (85), wherein: the gate valve (75) is displaceably arranged in a recess (77) in a housing wall region of the piston housing (43), the inlet (61) passing through the housing wall region of the piston housing (43), the recess (77) having a closed end region and an open end region opposite the closed end region, the open end region being connected to an inner space of the piston housing (43) via an opening (81) or via an opening (81) formed by a part of a branch passage extending around an inner side of the piston housing (43), the opening (81) is arranged at a height within the piston housing (43) which height is dimensioned such that, when the piston (45) is in the second end position, a lower edge of the opening (81) facing the second stop (49) abuts an upper side of the piston (45) facing an outer edge of the first chamber (51), -the gate valve (75) is designed such that, when the piston (45) reaches the second end position, the gate valve (75) is pushed into a locking position closing the inlet (61) by the pressure present in the first chamber (51); The return spring (85) is designed and arranged in the recess (77) such that the return spring (85) is tensioned by the gate valve (75) being displaced to the locking position and the return spring (85) pushes the gate valve (75) into the passing position when the compression force exerted by the opening (81) on the gate valve (75) drops below the restoring force of the tensioned return spring (85), and the gate valve (75) comprises a passage channel (79), which passage channel (79) extends through the gate valve (75) and is aligned and arranged such that the passage channel (79) forms a channel arranged in the inlet (61) and connects the first chamber (51) to the discharge line (23) connected to the pump (19) at the output side when the gate valve (75) is in the passing position.
  11. 11. The cleaning device of claims 6 to 10, wherein: the second chamber (53) is designed as a closed chamber, or The second chamber (53) is designed as a ventilation and exhaust chamber, to which an exhaust air duct (67) is connected, which exhaust air duct (67) is equipped with an outlet valve (65) or an outlet valve (65) designed as a check valve, and when the pressure in the second chamber (53) exceeds a predetermined upper pressure limit, the second chamber (53) is exhausted via the exhaust air duct (67), and which exhaust air duct (67) is connected to the supply line (21) via an air supply duct (71), which air supply duct (71) is equipped with an inlet valve (69) or an inlet valve (69) designed as a check valve, and when the pressure in the second chamber (53) falls below a predetermined lower pressure limit, the second chamber (53) is ventilated via the air supply duct (71).
  12. 12. The cleaning device of claims 6 to 11, wherein: the converter (55) comprises a spindle (57), which spindle (57) extends through the piston (45) and is displaced by an axial movement of the piston (45) into a rotational movement about its longitudinal axis corresponding to the axial movement, and which spindle is connected at the end to the shaft (39) of the wiper (35) such that the rotational movement of the spindle (57) causes a wiper movement of the wiper arm (41) corresponding to the rotational movement, and/or The wiper drive comprises at least one anti-rotation lock (59), or at least one anti-rotation lock (59) formed as a fixed pin extending through an outer edge region of the piston (45), the at least one anti-rotation lock (59) preventing the piston (45) from rotating about its longitudinal axis.
  13. 13. Cleaning device (1) according to claims 6 to 12, comprising one or more nozzles (33) arranged along the wiper arm (41) and connected to the exhaust air duct (31), wherein the exhaust air duct (31): is connected to the nozzle (33) via a connection and/or via a connection line (89) extending outside the housing (25) of the cleaning device (1) and has a line (91) extending through the wiper arm (41) inside the wiper (35), or Is connectable to a conduit (91), which conduit (91) is connected to the nozzle (33) via a plurality of conduit portions connected to each other during each pressure surge cleaning and extends through the wiper arm (41) within the wiper (35), wherein the conduit portions comprise: a first line portion (93) which is connected to the line (91) extending through the wiper arm (41) and extends along the shaft (39) of the wiper (35) or through the shaft (39), which line portion extends into a rotating disc (95) in a direction extending parallel to the shaft (39), which rotating disc (95) is connected to the main shaft (57), wherein the rotating disc (95) in the piston housing (43) is arranged on the side of the second stop (49) facing away from the first chamber (51), a second pipe portion (97), the second pipe portion (97) being connected to the first pipe portion (93) and extending radially outwardly within the rotating disc (95) and being open at the outside of the rotating disc (95), and -a third pipe portion (99), which third pipe portion (99) is connected to the exhaust air pipe (31), which third pipe portion (99) at least partly passes through the housing wall of the piston housing (43) and opens into the interior of the piston housing (43) at a position opposite the mouth of the second pipe portion (97) at the level of the mouth of the second pipe portion (97) when the piston (45) rotating with the spindle (57) is in the second end position.
  14. 14. A cleaning device (1) according to claims 6-13, comprising one or more nozzles (33) arranged along the wiper arm (41), which one or more nozzles (33) are connected or connectable to the exhaust air duct (31), which nozzles are arranged on that side of the wiper arm (41) which points in the direction of the initial position when the wiper arm (41) is in the end position.
  15. 15. Method for cleaning an outer part (3) of a sensor (5), the outer part (3) of the sensor (5) being in contact with a medium during a measurement mode, the method being executable with a cleaning device according to claims 4 to 14, in which method at least one cleaning process is performed, wherein each cleaning process comprises at least one pressure-impingement-fluctuation cleaning and ends with a wiper cleaning.
  16. 16. Measuring device with a cleaning device (1) 0 according to claims 1 to 14 and a sensor (5), wherein the cleaning device (1) is permanently or detachably connected to the sensor (5) and/or the pump (19) is arranged in the housing (25) of the cleaning device (1).

Description

Cleaning device for cleaning an outer part of a sensor Technical Field The invention relates to a cleaning device for cleaning an outer part of a sensor which is in contact with a medium during a measurement mode for measuring a measurement variable of the medium, a measuring device comprising a cleaning device and a sensor, and a cleaning method which can be performed by means of the cleaning device. Background Sensors for measuring a measurement variable of a medium are used in various types of applications for measuring a plurality of different measurement variables. In order to be able to measure a measurement variable such as, for example, a chemical, physical or biological measurement variable of the medium, these sensors generally have an outer portion which is in contact with the medium during a measurement mode, via or through which the measurement is carried out. For example, sensors (such as optical sensors, photometers, and spectrometers) have an outer portion that includes a window that is generally transparent to electromagnetic radiation through which electromagnetic radiation for measuring a measurement variable passes. Examples of sensors are calorimetric sensors, turbidity sensors, sensors for measuring the spectral absorption coefficient of a medium, and sensors for measuring the concentration of an analyte contained in a medium, such as sensors for measuring nitrite, nitrate or ammonium content. Another example is a sensor such as a conductivity sensor, the outer part of which is in contact with the medium during measurement and is the electrode surface. In many applications, there is a problem in that the outer portion of the sensor exposed to the medium may become soiled over time. Contamination of the external parts often leads to impairment of the measurement properties (in particular the measurement accuracy) of these sensors. Depending on the medium and application, contamination of different types and compositions may occur. Thus, the outer part of the sensor used in the purification system may become soiled over time, for example by solids (such as sand or hair), fat, biofilm formed on the outer part and/or algae growing on the outer part. To solve this problem, various types of cleaning devices for cleaning the outer portion of the sensor are known in the art. One example is a cleaning device equipped with a wiper for performing wiper cleaning. Thus, for example, DE 10-2011-978 a1 describes a measuring device with a sensor, whose end-side outer part is cleaned by means of a wiper, which is designed as part of a peripheral accessory. However, a wiper equipped with a wiping lip or brush may cause the outer portion to be cleaned to scrape with abrasive contaminants such as sand. Abrasive contaminants can lead to a deterioration of the achievable measurement accuracy, especially in the case of optical sensors. In the case of fiber contamination, there is also the risk that the fibers will wind up the wiper and/or the mechanical parts that cause the wiper to oscillate. In some cases, this may lead to impaired wiper mobility. Another example is a cleaning device operated with compressed air. For example, DE 10 2009 045472A1 describes a measuring system which comprises a sensor which can be mounted together with a mounting tube in a position of use and whose outer region which is in contact with the medium is cleaned with compressed air. In this case, the compressed air is supplied to the external part via a supply line extending through the fitting tube. Cleaning devices that operate with compressed air are particularly suitable for applications where fibrous contaminants may be present and are much more suitable than cleaning systems that operate with wipers. However, cleaning devices that operate with compressed air require that the compressed air be available at the location of use of the sensor. Furthermore, it must be ensured that the compressive force exerted by the compressed air on the contaminants is sufficiently large to remove the contaminants adhering to the outer part of the sensor to be cleaned. Thus, a compressed air generator (e.g. a compressor) is required to generate compressed air, the compressed air generator has to be more powerful as a whole, and thus the larger the compressed air generator as a whole, and the longer the supply line through which the compressed air is supplied to the outer part of the sensor to be cleaned. For example, a long supply line is required in combination with a sensor designed as an immersion probe which is mounted in the use position by means of a sensor suspension anchored above the medium. In this case, the sensor suspension for immersing the sensor in the purification tank may have a length of, for example, several meters. In these applications, the supply line extending from the compressed air generator to the sensor must therefore also have a correspondingly long length. Depending on the location of use, additional measures may be