EP1302584B1

EP1302584B1 - Device for cleaning concentration meter

Info

Publication number: EP1302584B1
Application number: EP20020022099
Authority: EP
Inventors: Kenichiro Aiki; Takeru Yamamoto
Original assignee: Tsudakoma Industrial Co Ltd
Current assignee: Tsudakoma Corp
Priority date: 2001-10-05
Filing date: 2002-10-02
Publication date: 2008-03-19
Anticipated expiration: 2022-10-02
Also published as: JP2003113575A; DE60225646D1; CN1188689C; JP4338008B2; CN1632529A; DE60225646T2; EP1302584A3; CN1412542A; EP1302584A2

Description

The present invention relates to a cleaning device for cleaning the measuring surface of a contact concentration meter for a slasher.
A contact concentration meter for measuring the concentration of a size has a measuring surface to be immersed in the size. A contact optical concentration meter has a built-in prism having a measuring prism surface to be brought into contact with a size.
When measuring the concentration of a size with the optical concentration meter, the measuring prism surface is brought into contact with the size, and a light beam is projected on the measuring prism surface. The optical concentration meter measures the refractive index of the size based on the refractive characteristic at the prism surface opposite to the side of the size, and detects density of the size based on the refractive index. Since the concentration of the size is proportional to the density of the size, the former can be determined from the latter.
The components of the size flowing in the vicinity of the measuring surface of the optical concentration meter adhere to the measuring surface, and form a size layer of a concentration higher than the actual concentration of the flowing size. The concentration of the size layer formed on the measuring surface increases as the thickness of the size layer increases gradually. Consequently, the adverse effect of the high-concentration size layer adhering to the measuring surface of the concentration meter on the measuring performance of the concentration meter increases with time, and the concentration meter becomes unable to measure the concentration of the size accurately. Since the high-concentration size layer comes off the measuring surface when the thickness thereof increases beyond a limit, the measuring performance of the concentration meter becomes very unstable and, consequently, the proper management of the concentration of the size becomes difficult.
US 5 563 737 discloses an arrangement for cleaning an optical window in an instrument such as a refractometer according to the first part of claim 1.
Accordingly, it is an object of the present invention to prevent the impediment of the accurate measurement of the concentration of a size by the adhesion of components of the size to the measuring surface of a contact concentration meter for measuring the concentration of the size on a slasher.
The present invention jets a cleaning fluid through a cleaning nozzle disposed opposite to the measuring surface of a contact-type concentration meter for measuring the concentration of a size against the measuring surface to remove the size adhering to the measuring surface from the measuring surface.
According to the present invention, a cleaning device for cleaning a measuring surface of a contact concentration meter kept in contact with a size on a slasher includes a cleaning nozzle disposed opposite to the measuring surface of the contact concentration meter, wherein steam is jetted through the cleaning nozzle against the measuring surface of the contact concentration meter to clean the measuring surface.
Thus, a high-concentration size layer formed on the measuring surface by the deposition of the components of the size can be removed from the measuring surface by the jet of the cleaning fluid. Since the measuring surface is kept in direct contact with the size, the concentration meter is able to measure the concentration of the size accurately.
Further described is a cleaning device for cleaning a measuring surface of a contact concentration meter including a cleaning member disposed so as to be movable along the measuring surface of the contact concentration meter, wherein the cleaning member wipes the measuring surface of the contact concentration meter to clean the measuring surface.
Thus, the high-concentration size layer deposited on the measuring surface can be wiped off the cleaning surface with the cleaning member and the concentration meter is able to measure the concentration of the size accurately.
The contact concentration meter is an optical concentration meter, and the cleaning fluid is steam. Only concentrations of the size measured by the contact concentration meter while the cleaning device is not in operation are used as effective concentrations.
If the components of the size deposit of the measuring surface of the optical concentration meter, i.e., the contact concentration meter, and a high-concentration size layer is formed over the measuring surface, the optical concentration meter measures the concentration of the high-concentration size layer different from the true concentration of the size. Since the high-concentration size layer formed over the measuring surface of the optical concentration meter is removed by the cleaning device, actual concentration of the size can be accurately measured.
Since the cleaning fluid is a component of the size, the quality of the size is not changed significantly by the cleaning fluid jetted into the size, foreign matters are not introduced into the size, and there is no possibility that the warp yarns are contaminated with foreign matters
The cleaning fluid is steam, which are components of the size, or may be a combination of some of those. Preferably, the temperature of the cleaning fluid is high.
Since the steam as a cleaning fluid has a small specific weight, the change of the concentration of the size can be limited to the least unavoidable extent when steam is jetted into the size. Since steam dissolves in the size, bubbles are not formed on the surface of the size and the warp yarns are not irregularly sized due to the adhesion of bubbles thereto. Since steam generates heat of condensation when the same dissolves in the size, the size is heated and the infiltration of the size is enhanced.
Since only measurements provided by the contact concentration meter while the cleaning operation is interrupted is regarded as effective, measurements that are expected not to indicate the actual concentration of the size are eliminated, and the concentration of the size can be accurately measured. Generally, the size around the measuring surface becomes heterogeneous during the cleaning operation because the high-concentration size layer removed from the measuring surface is scattered in the vicinity of the measuring surface, and the concentration of the size around the measuring surface does not represent the concentration of the entire size. Since only the measurements provided by the contact concentration meter are regarded as effective, the faulty measurement of the concentration of the size can be avoided.
The above and other objects, features and advantages of the present invention will become more apparent from the following description taken in connection with the accompanying drawings, in which:

Fig. 1 is a schematic side elevation of a slasher;
Fig. 2 is a diagrammatic view of a size supply system included in the slasher, and a cleaning device for cleaning a concentration meter for measuring the concentration of a size;
Fig. 3 is a schematic, enlarged sectional view of a cleaning device in a first embodiment according to the present invention for cleaning a contact concentration meter;
Fig. 4 is a block diagram of the size supply system and a control system;
Fig. 5 is a schematic side elevation of the contact concentration meter shown in Fig. 3 as placed in a sizing tank; and
Fig. 6 is a schematic side elevation of a cleaning device for cleaning a contact concentration meter not forming part of the invention.

Referring to Fig. 1 showing a slasher 2 to which a cleaning device 1 of the present invention is applied, the slasher 2 is provided with a size tank 5 containing a size 4, size circulation tank 6, a pair of sizing rollers 7 and a pair of squeeze rollers 8. A warp 3 travels via a guide roller 9 to the pair of sizing rollers 7. The sizing rollers 7 immerse the warp 3 in the size 4 contained in the size tank 5. The warp 3 thus sized is squeezed by the pair of squeeze rollers 8. Warp yarns forming the warp 3 are thus impregnated with the size 4.
Then, the sized warp 3 travels into a drying unit 10. The warp 3 is divided into two groups of warp yarns. The two groups of warp yarns are dried by two preparatory drying units each including two drying cylinders 11 and a guide roller 12, the two groups of warp yarns are joined together in the warp 3 again, and then the warp 3 is dried by a finish drying unit including two drying cylinders 11 and a guide roller 13. The thus dried warp 3 is divided into an upper warp and a lower warp by a dividing rod 16, the warp 3 is guided by a guide roller 14 to a take-up beam 15, and is wound on the take-up beam 15.
Fig. 2 shows a cleaning device 1 of the present invention in combination with a size supply system for supplying and circulating the size 4. The size 4 is contained in a size supply tank 17 connected to a size circulation tank 6 by a supply pipe 18 provided with a solenoid valve 19. The solenoid valve 19 is opened to supply the size 4 from the size supply tank 17 to the size circulation tank 6. The solenoid valve 19 is controlled by a size controller 20 in an on-off control mode. The size controller 20 controls the solenoid valve 19 according to the level of the size 4 in the size circulation tank 6 measured by a float-type level meter 21. The size controller 20 opens the solenoid valve 19 when the level of the size 4 in the size circulation tank 6 drops below a lower limit level to supply the size 4 into the size circulation tank 6, and closes the solenoid valve 19 when the level of the size 4 in the size circulation tank 6 rises beyond an upper limit level to stop supplying the size 4 into the size circulation tank 6. An ultrasonic liquid level meter that sends out a ultrasonic wave toward the surface of the size 4 and measures time spent for the ultrasonic wave to return thereto may be used instead of the float-type level meter 21.
The size 4 contained in the size circulation tank 6 is supplied continuously into the sizing tank 5 through a circulation pipe 22 having one end connected to the bottom wall of the sizing tank 5 and the other end connected to the bottom wall of the size circulation tank 6. The circulation pipe 22 is provided with a circulation pump 23 for pumping the size 4 into the sizing tank 5, and a contact concentration meter 30. The size 4 contained in the sizing tank 5 overflows an overflow weir 24 and returns into the size circulation tank 6. The concentration of the size 4 is properly adjusted while the size 4 is circulated through the sizing tank 5 and the size circulation tank 6.
The cleaning device 1 of the present invention for cleaning the contact concentration meter 30 is provided with a cleaning nozzle 32 disposed opposite to the measuring surface 29 of the contact concentration meter 30. The contact concentration meter 30 is fixedly held on a concentration meter holder 33 with its measuring head 31 laid inside the concentration meter holder 33 so that the measuring surface 29 is in contact with the size 4. The cleaning nozzle 32 is disposed in and held on the concentration meter holder 33 opposite to the measuring surface 29 to jet a cleaning fluid across the flow of the size 4 in the concentration meter holder 33 against the measuring surface 29. The tip of the cleaning nozzle 32 is spaced a distance apart from the measuring surface 29 to enable the size 4 to flow through the concentration meter holder 33. The concentration meter holder 33 is placed in the circulation pipe 22 on the upstream side of the circulation pump 23.
High-pressure, high-temperature steam 34a, i.e., a cleaning fluid 34, is supplied from a steam source 35 through a steam supply pipe 36 provided with a solenoid valve 25 and a restrictor 27 to the cleaning nozzle 32. Steam 34a is jetted through the cleaning nozzle 32 against the measuring surface 29 to clean the measuring surface 29. The steam source 35, the steam supply pipe 36, the solenoid valve 25 and the restrictor 27 constitute a cleaning steam supply system 49. The cleaning fluid 34 is a component of the size 4. The cleaning fluid 34 s steam. The cleaning fluid, as a component of the size 4, does not change the quality of the size 4 significantly when mixed in the size 4. A branch pipe provided with a restrictor 26 is branched from the steam supply pipe 36, and branch pipes 37 respectively provided with restrictors 28 and 38 are branched from the branch pipe provided with the restrictor 26. The branch pipe 37 provided with the restrictor 28 is connected to a heating nozzle 39 placed in the sizing tank 5, and the branch pipe 37 provided with the restrictor 38 is connected to a heating nozzle 40 placed in the size circulation tank 6. The steam source 35, the steam supply pipe 36, the branch pipes 37, the restrictors 28 and 38, and the steam jetting nozzles 39 and 40 constitute a size heating system 41. The steam source 35 supplies high-temperature, high-pressure steam to both the size heating system 41 and the cleaning steam supply system 49.
Fig. 3 shows an essential part of the cleaning device 1 for cleaning the contact concentration meter 30. The contact concentration meter 30 is an optical concentration meter. The contact concentration meter 30 is held on the concentration meter holder 33 with its axis extended perpendicularly to the direction of flow of the size 4 in the concentration meter holder 33. The measuring surface 29 is in contact with the flowing size 4. The measuring surface 29 of the contact concentration meter 30 is the top surface of a prism 42 having the shape of a rectangular frustum. A light beam 44 emitted by a light source 43 included in the contact concentration meter 30 travels through the bottom surface of the prism 42 having a refractive index greater than that of the size 4 into the prism 42, is reflected in a total reflection mode by the side surfaces and the top surface, i.e., the measuring surface 29, of the prism 42, and falls on a light sensor 45. In some cases the light beam 44 travels through the prism 42 into the size 4.
When measuring the concentration of the size 4, a contact concentration meter (optical concentration meter) 30 projects the light beam 44 on the measuring surface 29, and travel through the size 4 so that the contact concentration meter 30 measures a critical incident angle of the light beam 44 and also measures the refractive index of the size 4 based on the critical incident angle and a known prism refractive index, then outputs the thus measured refractive index of the size 4 to a concentration determining device 46. As mentioned above, the concentration of the size 4 is proportional to the density of the same. The concentration determining device 46 determines a density on the basis of the refractive index given thereto, and calculates a concentration by using the density of the size 4.
Fig. 4 is a block diagram of the size supply system and the size controller 20 for controlling the solenoid valves 19, 25 and 26. While the slasher 2 is in operation, the level meter 21 measures the level of the size 4 in the size circulation tank 6. Upon the detection of the drop of the level of the size 4 to the lower limit level by the level meter 21, the size controller 20 opens the solenoid valve 19 to supply the size 4 contained in the size supply tank 17 into the size circulation tank 6. Upon the detection of the rise of the level of the size 4 in the size circulation tank 6 to the upper limit level by the level meter 21, the level meter 21 sends a signal to that effect to the size controller 20. Then, the size controller 20 closes the solenoid valve 19 to stop supplying the size 4 into the size circulation tank 6.
A timer 47 is connected to the size controller 20 for interactive signal exchange. The timer 47 is set for a cleaning time and a cleaning interval. While the slasher 2 is in operation, the measuring head 31 of the contact concentration meter (optical concentration meter) 30 is immersed in the size 4 such that the measuring surface 29 is wetted with the size 4 to measure the concentration of the size 4. Therefore, the components of the size 4 adhere to the measuring surface 29 and, eventually, the components adhering to the measuring surface 29 forms a high-concentration size layer on the measuring surface 29. The thickness of the high-concentration size layer increases with time.
The timer 47 gives a cleaning command signal continuously for a cleaning time to the size controller 20 at the cleaning interval. The cleaning interval (cleaning period) is determined taking into consideration the condition of the size 4 and the rate of adhesion of the components of the size 4 to the measuring surface 29. The cleaning time is determined such that the components of the size 4 adhering to the cleaning surface 29 can be completely removed in the cleaning time.
Upon the reception of the cleaning command signal, the size controller 20 opens the solenoid valve 25 and keeps the solenoid valve 25 open for the cleaning time. Then, steam 34a supplied by the steam source 35 flows through the steam supply pipe 36, the solenoid valve 25 and the restrictor 27 to the cleaning nozzle 32. Steam 34a is jetted through the cleaning nozzle 32 against the measuring surface 29 of the measuring head 31 for the cleaning time to clean the measuring surface 29. The cleaning operation is performed periodically at intervals determined taking into consideration the rate of adhesion of the components of the size 4 to the measuring surface 29.
As mentioned above, since the measuring surface 29 is wetted with the size 4, the components of the size 4 adhere to the measuring surface 29 and the components adhering to the measuring surface 29 forms a high-concentration size layer on the measuring surface 29. The high-concentration size layer is blown off the measuring surface 29 by high-pressure steam 34a jetted through the cleaning nozzle 32 of the cleaning device 1 against the measuring surface 29. Since the pressure of steam 34a is high, steam 34a is jetted at a high velocity through the cleaning nozzle 32 and hence the high-concentration size layer can be removed by jetting only a small amount of steam 34a.
Since the high-concentration size layer is removed from the measuring surface 29 of the contact concentration meter 30 by the cleaning operation and the measuring surface 29 is in direct contact with the size 4, the contact concentration meter 30 is able to measure the concentration of the size 4 accurately. The size controller 20 gives the concentration determining device 46 a measurement interruption signal indicating the interruption of concentration measurement, and the concentration determining device 46 omits data obtained while the cleaning device 1 is in operation. The size controller 20 performs a control operation for controlling the temperature of the size contained in the sizing tank 5 as well as control operations for controlling the supply of the size 4 and the cleaning of the measuring surface 29. A temperature sensor 48 placed in the sizing tank 5 measures the temperature of the size 4. The temperature sensor 48 sends an upper limit signal upon the measurement of a temperature equal to an upper limit temperature, and a lower limit signal upon the measurement of a temperature equal to a lower limit temperature to the size controller 20.
When the temperature of the size 4 measured by the temperature sensor 48 is not higher than the lower limit temperature, the size controller opens the solenoid valve 26 to supply steam 34a supplied by the steam source 35 through the supply pipes 37, the restrictors 28 and 38 to the steam jetting nozzles 39 and 40. Steam 34a is jetted through the steam jetting nozzles 39 and 40 into the sizing tank 5 and the size circulation tank 6 to heat the size 4 contained in the sizing tank 5 and the size circulation tank 6. When the temperature of the size 4 measured by the temperature sensor 48 is not lower than the upper limit temperature, the size controller 20 closes the solenoid valve 26 to stop jetting steam 34a through the steam jetting nozzles 39 and 40.
The temperature control operation maintains the size 4 at a temperature proper for sizing. Since steam 34a, i.e., the cleaning fluid 34, is a component of the size 4 and the temperature of steam 34a is high, steam 34a heats the size 4 and enhances the infiltration of the size 4 into the warp yarns of the warp 3. Since the cleaning fluid 34 is a component fluid of the size 4, the cleaning fluid 34 jetted into the size 4 does not change the quality of the size 4 and does not introduce foreign matters that will adhere to the warp yarns into the size 4. Possible cleaning fluids other than steam 34a and not forming part of the invention include water and the size. Preferably, those cleaning fluids are heated at high temperatures and are used individually or some of those cleaning fluids are used in combination.
Fig. 5 shows the cleaning nozzle 32 disposed in the sizing tank 5 for cleaning the contact concentration meter (optical concentration meter) 30 placed in the sizing tank 5. The contact concentration meter 30 is held on a wall of the sizing tank 5 with its measuring head 31 inclined upward toward the interior of the sizing tank 5. The measuring surface 29 of the measuring head 31 is in contact with the size 4 contained in the sizing tank 5. The cleaning device has a cleaning nozzle 32 held on the bottom wall of the sizing tank 5. A free end part of the cleaning nozzle 32 is bent such that the tip of the cleaning nozzle 32 is directed toward the measuring surface 29. The contact concentration meter (optical concentration meter) 30 and the cleaning nozzle 32 may be placed in the size circulation tank 6.
The cleaning operation of the cleaning devices shown in Figs. 2 and 5 may be performed in connection with the operation of the size heating system 41 for jetting steam 34a. The size controller 20 jets high-temperature, high-pressure steam 34a into the size 4 to heat the size 4 upon the detection of the drop of the temperature of the size 4 to the lower limit temperature by the temperature sensor 48 of the size heating system 41. At the same time, high-temperature steam 34a is jetted through the cleaning nozzle 32. When the cleaning operation is thus performed in connection with the size heating operation, the cleaning operation can be controlled by the size heating system 41 and, since the supply of steam 34 to the cleaning nozzle 32 and the heating nozzles 39 and 40 can be controlled by a single solenoid valve, the cost of the cleaning device can be reduced.
The cleaning operation may be performed in connection with a size supply operation for supplying the size 4 into the size circulation tank 6. The size controller 20 starts a size supply operation for supplying the size 4 into the size circulation tank 6 upon the detection of the drop of the level of the size 4 in the size circulation tank 6 to the lower limit level by the level meter 21. The cleaning operation for jetting the high-temperature, high-pressure steam 34a through the cleaning nozzle 32 is started every time the size supply operation is started. The period of the cleaning operation (time interval between the successive cleaning operations) can be properly adjusted by properly adjusting the distance between the upper and the lower level of the surface of the size 4. The cleaning operation is performed according to the consumption of the size, so that the cleaning operation can be performed at substantially predetermined intervals to remove the high-concentration size layer adhering to the measuring surface 29 before the high-concentration size layer affect the measurement of the concentration of the size 4.
Fig. 6 shows a cleaning device 1, not forming part of the present invention, for cleaning a contact concentration meter (optical concentration meter) 30 placed in the size circulation tank 6. The cleaning device 1 includes a hydraulic cylinder actuator 50 provided with an actuator rod 51 and attached to the inner surface of a side wall of the size circulation tank 6, and a cleaning member 52, such as a sponge block, attached to a free end part of the actuator rod 51. The cleaning member 52 is moved vertically by the actuator rod 51 of the hydraulic cylinder actuator 50 so as to wipe the measuring surface 29 of the measuring head 31.
While the cleaning device 1 is not in operation, the cleaning member 52 is held at a waiting position above the measuring surface 29 and is separated from the measuring surface 29. Thus, the cleaning member 52 does not obstruct contact between the size 4 and the measuring surface 29 and hence the concentration of the size 4 can be accurately measured. The hydraulic cylinder actuator 50 reciprocates the cleaning member 52 vertically several times along the measuring surface 29 to remove the high-concentration size layer adhering to the measuring surface 29. After the completion of the cleaning operation, the cleaning member 52 is returned to the waiting position.
The measuring surface 29 thus cleaned is able to be in direct contact with the size 4 and hence the contact concentration meter (optical concentration meter) 30 is able to measure the concentration of the size accurately. A rubber wiper, a thin, elastic steel plate, a fabric or a brush may be used instead of the sponge block as the cleaning member 52.
The contact concentration meter 30 does not need to measure the concentration of the size continuously; the contact concentration meter 30 may measure the concentration of the size periodically at predetermined intervals, and a signal indicating a measured concentration of the size may be given to the concentration determining device every time the concentration is measured. The cleaning operation may be performed immediately before the measurement of the concentration of the size instead of at a predetermined period (time interval).

Claims

A cleaning device (1) for cleaning a measuring surface (29) of a contact concentration meter (30) kept in contact with a size (4) on a slasher (20), said cleaning device (1) comprising a cleaning nozzle (32) disposed opposite to the measuring surface (29) of the contact concentration meter (30);
characterized in that steam (34a) is jetted through the cleaning nozzle (32) against the measuring surface (29) of the contact concentration meter (30) to clean the measuring surface (29)
The cleaning device (1) according to claim 1, wherein the contact concentration meter (30) is an optical concentration meter.
The cleaning device (1) according to any of claims 1 or 2, wherein only concentrations of the size measured by the contact concentration meter (30) while the cleaning device (1) is not in operation are used as effective concentrations.