DEVICE AND METHOD FOR DAMPENING A MATERIAL WEB

Abstract

A method for at least one of regulating and controlling at least one dampening device suitable for dampening a material web, the method comprising the steps of: providing that the dampening device includes a valve which includes at least one electromagnetic force transmitter, a reset force transmitter, a valve body, the dampening device further including a control unit and an application nozzle; and performing, by the dampening device, a cleaning cycle, the valve being a proportional valve, the proportional valve pulsing about a set target value, a deviation from the set target value occurring by way of a timing such that the deviation from the set target value results, the deviation being at least one of a positive deviation and a negative deviation.

Claims

1. A method for at least one of regulating and controlling at least one dampening device suitable for dampening a material web, the method comprising the steps of: providing that the dampening device includes a valve which includes at least one electromagnetic force transmitter, a reset force transmitter, a valve body, the dampening device further including a control unit and an application nozzle; and performing, by the dampening device, a cleaning cycle, the valve being a proportional valve, the proportional valve pulsing about a set target value, a deviation from the set target value occurring by way of a timing such that the deviation from the set target value results, the deviation being at least one of a positive deviation and a negative deviation.

2. The method according to claim 1, wherein the proportional valve is configured for being opened and closed at least partially and pulsating rapidly about the set target value, wherein the deviation from the set target value lasts less than 0.3 seconds, and the proportional valve is configured for pulsating repeatedly, wherein the material web is a paper web, a cardboard web, or a fibrous web.

3. The method according to claim 2, wherein the deviation from the set target value lasts less than 0.1 seconds.

4. The method according to claim 1, wherein the method includes providing at least two of the dampening device each of which is at least one of controlled and adjusted, wherein a respective one of the dampening device that pulsates in the cleaning cycle is arranged adjacent to at least one other of the dampening device which is configured for performing a pulsation in an opposite direction.

5. The method according to claim 4, wherein the method includes providing more than three of the dampening device.

6. The method according to claim 4, wherein the pulsation in the opposite direction exhibits only half an amplitude or a time duration of the deviation from the set target value.

7. The method according to claim 1, wherein at least one of the cleaning cycle and a pulsating is performed at a time (a) when the material web of reduced quality is being produced, or (b) when a machine for producing the material web is in a specific operating state.

8. The method according to claim 1, wherein when the proportional valve is pulsing the proportional value is performing a pulsation, wherein at least one of the cleaning cycle and the pulsation deviates only in one direction from the set target value, wherein at least one of the cleaning cycle and the pulsation can also be started when the proportional valve is fully closed or fully open.

9. A dampening device suitable for dampening a material web, the dampening device comprising: a valve including at least one electromagnetic force transmitter, a reset force transmitter, a valve body; a control unit; and an application nozzle, the valve being a proportional valve and having a control range, the valve being configured for enabling the control range to be set to a target value in at least 16 steps, the dampening device, by way of the control unit, being configured for performing at least one of a cleaning cycle and a pulsation such that the proportional valve pulses about the target value, a deviation from the target value occurring by way of a timing such that the deviation from the target value results, the deviation being at least one of a positive deviation and a negative deviation.

10. The dampening device according to claim 9, wherein the valve body of the proportional valve traverses a distance of less than 5 mm from closed to open, the valve being configured for enabling the control range to be set to a target value in at least 100 steps.

11. The dampening device according to claim 10, wherein the distance is less than 2 mm.

12. The dampening device according to claim 9, wherein the electromagnetic force transmitter is configured to fully open or fully close the proportional valve from any target value in a time of less than 0.3 seconds.

13. The dampening device according to claim 12, wherein the time is less than 0.1 seconds.

14. The dampening device according to claim 9, wherein the electromagnetic force transmitter is configured to adjust the proportional valve to any target value in a time of less than 0.3 seconds.

15. The dampening device according to claim 9, further comprising an application orifice, wherein the proportional valve is directly followed by the application nozzle or the application orifice, and no additional functional elements are used for pulsation damping.

16. The dampening device according to claim 9, wherein the reset force transmitter of the proportional valve includes a mechanical spring element, a magnetic force transmitter, an electromagnetic force transmitter, or a pneumatic force transmitter.

17. A method of using at least two dampening devices, the method comprising the steps of: providing that each of the at least two dampening devices is suitable for dampening a material web, each of the at least two dampening devices including respectively: a valve including at least one electromagnetic force transmitter, a reset force transmitter, a valve body; a control unit; and an application nozzle, the valve being a proportional valve and having a control range, the valve being configured for enabling the control range to be set to a target value in at least 16 steps, the dampening device, by way of the control unit, being configured for performing at least one of a cleaning cycle and a pulsation such that the proportional valve pulses about the target value, a deviation from the target value occurring by way of a timing such that the deviation from the target value results, the deviation being at least one of a positive deviation and a negative deviation; using each of the at least two dampening devices in a method for at least one of regulating and controlling the at least two dampening devices, the method comprising the steps of: performing, by the at least two dampening devices, the cleaning cycle, the proportional valve pulsing about the target value, the deviation from the target value occurring by way of the timing such that the deviation from the set target value results, the deviation being at least one of the positive deviation and the negative deviation, the at least two dampening devices being arranged over a width of the material web and being configured for applying a plurality of different moistening levels to a plurality of different zones.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0050] The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention will be better understood by reference to the following description of embodiments of the invention taken in conjunction with the accompanying drawings, wherein:

[0051] FIG. 1 is a schematic partial representation of a possible embodiment of a dampening device for moistening a material web in a sectional view;

[0052] FIG. 2 a schematic characteristics curve to explain the control range for the application volume in the method according to one claim of the invention; and

[0053] FIG. 3 a schematic partial representation of one possible embodiment of a method and a device of the invention.

[0054] Corresponding reference characters indicate corresponding parts throughout the several views. The exemplification set out herein illustrates at least one embodiment of the invention, and such exemplifications are not to be construed as limiting the scope of the invention in any manner.

DETAILED DESCRIPTION OF THE INVENTION

[0055] FIG. 1 shows a schematic partial representation of a possible embodiment of a dampening device 1. Dampening device 1 includes a proportional valve 2 with an electromagnetic force transmitter 3 and a reset force transmitter 4, which are capable of moving a valve body 10 within a control range 9. The valve body is controlled or regulated to the target value by control unit 5. The controlled volume flow of the application medium is then sprayed onto a material web 8 by way of an application nozzle 6 or application orifice 7, wherein the application nozzle is shaped having a tapering cross-section. Due to the high shear forces at application orifice 7, the emerging liquid is atomized into small droplets which allow uniform moistening of material web 8.

[0056] FIG. 2 shows a schematic partial representation to explain the control range for the application volume in the method according to the present invention. The control range is shown on the vertical axis as a percentage value of the valve opening or application volume. The horizontal axis relates to time [t]. A pulsation movement is shown with a cleaning cycle 12. Opposite pulsation 13 shows the inversely proportional opening of the adjacent valves, each of which in this application example deviate from target value 11 by only half the amplitude of cleaning cycle 12. Target value 11 in this example is shown as 50% of the possible valve opening or application amount.

[0057] FIG. 3 shows a schematic partial representation in a top view of a possible embodiment of a method of the present invention. Several application nozzles 6 with corresponding application orifices 7 are shown, which are arranged adjacent to one another across the width of material web 8. The sprayed-on application medium is shown schematically by dotted lines. The center nozzle is currently running through a cleaning cycle 12, while the two adjacent nozzles perform an opposite pulsation 13. In this way, material web 8 is dampened at a largely constant average rate. If cleaning cycle 12 and opposite pulsations 13 are conducted at a correspondingly rapid rate, the moisture in the paper can be more easily balanced locally and the quality of dampening remains accordingly acceptable. In the illustration, material web 8 runs perpendicular to the illustration along a Z-axis which is not shown. In this case, application nozzles 6 are each part of a dampening device 1, which includes a proportional valve 2 which is not shown. In the illustrated method, cleaning cycle 12 is conducted by a dampening device 1, with adjacent dampening devices 1 performing an opposite pulsation 13.

COMPONENT IDENTIFICATION LISTING

[0058] 1 Dampening device [0059] 2 proportional valve [0060] 3 electromagnetic force transmitter [0061] 4 resetting force transmitter [0062] 5 control unit [0063] 6 application nozzle [0064] 7 application orifice [0065] 8 material web [0066] 9 control range [0067] 10 valve body [0068] 11 target value [0069] 12 cleaning cycle [0070] 13 opposite pulsation

[0071] While this invention has been described with respect to at least one embodiment, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.