EP0731211B1 - Jet device - Google Patents

Description

The invention relates to a beam device for a machine for making a web, in particular a paper or cardboard web, according to claim 1, the use of a nozzle device for Delivery of a jet of liquid under pressure having pointed tailor, according to claim 7 and the use of a nozzle device to deliver a pressurized Liquid jet cleaning device, according to claim 8.

There are numerous in papermaking machines Conveyor belts, especially fabric belts, are used, which is contaminated in the course of operating the machine become; Meshes or pores of the ribbons for example of paper fibers, adhesives or Impact added. To function properly the conveyor belt, especially in the dryer section the paper making machine, to ensure the conveyor belt must be cleaned. A beam device that can be used for this, which is designed as a cleaning device known from DE 92 08 909 U1. In this publication the thought was expressed, across the direction of walking movable spray nozzles of the conveyor belt To be provided by spraying the conveyor belt Clean the liquid.

Tailors are also known, the one within a paper making machine a conveyor belt moving material web apply a beam to a strip of Material web, especially one as a ribbon designated threading strip, to separate the is passed through the paper making machine, to then thread the entire web of material.

It has been found that the space requirement within a paper machine by using Cleaning facilities and tip cutters very much is large and that in many cases a complicated one Structure results.

A nozzle device is known from EP 0 009 909 A1 to deliver a jet of liquid under pressure for cleaning a conveyor belt a paper machine. The nozzle device includes a switching device with whose help the pressure of the liquid jet is adjustable. A first pressure of the liquid jet is in a range of approximately 20 bar to 30 bar. By actuation the switching device, the pressure of the Liquid jet reduced to approximately 2 bar. With Help of the nozzle device and the interacting with it Switching device can be the conveyor belt cleaned with different intensity become.

It is an object of the invention to provide a beam device for a machine for producing a material web, especially a paper or cardboard web, to create the preferably a simple one Has structure and requires little space inside the machine.

A beam device is used to solve the problem proposed that mentioned in claim 1 Features. The beam device has one Nozzle device for dispensing a pressurized on the material web and / or on the material web leading conveyor belt directed liquid jet on. The beam device includes also a switching device with the help the pressure at which the liquid jet is applied to the Conveyor belt or the material web hits, is adjustable. When you press the Liquid jet is the jet device as Tip cutter to separate a strip from the material web and at a second print of the Liquid jet as a cleaning device for Can be used to clean the conveyor belt. With help the switching device can be ensured that the second pressure of the liquid jet so is small that the conveyor belt when cleaning suffered no harm.

An embodiment is particularly preferred the beam device, which is characterized by that the switching device to a supply facility acts through which the nozzle device is supplied with the liquid. The constructive Effort required to implement the described here Beam device is required can be with it to a minimum, so that on the one hand the additional space requirement and on the other hand the costs are minimal for the switching device.

Further configurations result from the others Dependent claims.

The object of the invention also relates to the use one a nozzle device for dispensing a jet of liquid under pressure having pointed tailor with the characteristics of claim 7 as a device for cleaning a Conveyor belt of a paper making machine. The subject matter of the invention therefore also relates the use of a cleaning device for cleaning the conveyor belt of a machine for manufacturing a material web with the characteristics of Claim 8. In both cases, a switching device provided by means of which the pressure is adjustable with which the liquid jet onto the conveyor belt or the material web hits.

Figur 1

eine Prinzipskizze eines Spitzenschneiders in Seitenansicht;

Figuren 2 bis 4

verschiedene mit dem Spitzenschneider gemäß Figur 1 herstellbare Schnittlinien, und

Figur 5

eine Prinzipskizze einer Reinigungsvorrichtung.

The invention is explained in more detail below with reference to the drawing. Show it:

Figure 1

a schematic diagram of a tip cutter in side view;

Figures 2 to 4

different cutting lines that can be produced with the tip cutter according to FIG. 1, and

Figure 5

a schematic diagram of a cleaning device.

As already indicated above, there are beam devices known with the help of a liquid jet on a conveyor belt or one of these guided material web can be directed. Such devices are called tip cutters or cleaning device. The figures 1 to 4 relate, for example, to a tip cutter, Figure 5 shows a cleaning device.

FIG. 1 shows a section of a machine 1 for making a web. In the following, purely can be assumed as an example that it is a paper making machine, which has a number of rollers around which the web to be produced, namely the paper web 3 with With the help of a conveyor belt, namely a dryer fabric 5 is led around. They are exemplary here two drying cylinders 7 and 9 indicated, the Central axes indicated on an imaginary line 11 are. Below this line 11 is another Roller, for example a web guide roller or a drying cylinder indicated.

Between the drying cylinders 7 and 9 is a Tip cutter 15 trained beam device arranged, which has a nozzle device 17, with the help of a liquid jet, not shown here on the surface of the paper web 3 is directed. The nozzle device 17 is on one transverse to the direction of conveyance indicated by an arrow the web 3 extending support beam 19 attached. By means of a suitable roller device 21 the nozzle device 17 is displaceable transversely to the web 3 stored. The support beam 19 is over a support arm 23 pivotally attached to a bearing 25. The pivotal movement is determined by a suitable one Drive device, for example a hydraulic or pneumatic cylinder device 27 includes, causes. In Figure 1 is with solid lines indicate the working position of the tip cutter 15 reproduced. With the help of dashed lines Lines is the withdrawn from which Track surface swung away rest position of the Tip cutter 15 shown.

The nozzle device 17 comprises a nozzle holder 29, the single nozzle not shown here has, with the help of liquid under high Pressure on the web 3 is directed. In the operation of the Tip cutter 15 leads the movably mounted Nozzle holder 29 opposite the nozzle device 17 a relative movement. In the area of impact of the Liquid jet on the web 3 results in a Cutting line through the superposition of the conveying movement the path 3 and the relative movement of the Nozzle carrier 29 opposite the nozzle device 17 not straight, but wavy. The speed of the web 3 respectively the dryer fabric 5 is also called the machine speed denotes v.

In the exemplary embodiment shown here indicated by an arrow curved in a circular arc, that the nozzle holder 29 opposite the nozzle device 17 a rotational movement by one Axis of rotation 31 performs so that one at a distance attached to the axis of rotation 31 on the nozzle holder 29 Single nozzle follows a circular path.

On the basis of Figures 2 to 4 are cutting lines shown, when using a tip cutter 15 with a rotating nozzle carrier 29 if provided with a single nozzle 33 is provided, which is indicated in Figure 2. Figure 2 shows the edge region of the web 3, which, like indicated by an arrow on the rotating Nozzle carrier 29 is passed. The liquid jet 35, which on the surface of the web 3 hits, leaves a cutting line, the closed Includes loops and about the shape of a Cycloid features. Is above the cutting line the transfer strip 37, which after a web break or when starting up the machine for manufacture a paper web threaded through the machine 1 becomes. Below the cutting line is the remaining web or residual paper web 39, which is reprocessed and for example in the basement. The Areas of paper lying within the closed loops 41 form waste that may uncontrolled with the dryer 5 through the machine passed through to produce a web becomes.

The rotational speed of the nozzle carrier 29 is therefore preferably the machine speed v adapted that the of the web 3 in Path s covered at least in the direction of the arrow is equal to twice the distance r between the individual nozzles 33 of the axis of rotation 31 multiplied by the mathematical number π (3.14159 ...) representing the ratio from circumference to diameter.

The section line S shown in Figure 2 shows an operating case in which the rotational speed of the nozzle carrier 29 is so small that the Path 3 covered distance s is less than twice the distance r of the individual nozzle 33 from the Axis of rotation 31 multiplied by π.

Figure 3 shows the limit case where the machine speed v is so large that during the time t covered by the path t of the path 3 is the same size as the double distance r multiplied with π.

It can be seen that the section line S approximately Form of a cycloid that has no closed Loops shows. The transfer strip 37 is thus separated from the residual paper web 39 without waste.

The limit speed given in this case can be determined from the equation v = 2 · r · n · π, where n denotes the speed of the nozzle carrier 29 becomes.

Is the distance r of the individual nozzle 33 to the axis of rotation 31 for example 25mm and is used for the speed of the nozzle holder 29 n = 2000 / min, see above turns out that the machine speed v must be approximately 314.16 m / min. An optimal one Separation between transfer strips 37 and Residual paper web 39 is reached when the machine speed v is larger than this defined limit speed, what for this numerical example shown is easily possible, especially with paper making machines that Machine speeds of more than 1600 meters / min to reach.

An optimal cutting line S is shown in FIG. 4.

From the above it is clear that the nozzle holder 29 compared to the nozzle device 17 also can perform an oscillating movement at which the single nozzle 33 opposite the web 3 one Performs a pendulum motion that is roughly on a line takes place, which is transverse to the direction of the web 3. It is also possible for the nozzle holder 29 a wobble movement relative to the nozzle device 17 executes in addition to that described Given an oscillatory movement a movement component is where the nozzle carrier alternates in the conveying direction and against the conveying direction of the Lane 3 moves.

It is essential in all cases that the back and forth Movement of the individual nozzle 33 or Nozzle carrier 29 so on the machine speed is agreed that the section line S is not a closed one Has loops, as shown by Figure 2 have been explained.

In Figure 1 it was shown that the tip cutter 15 a liquid jet onto an area the web releases between two rollers lies between the drying cylinder 9 and the Web guide roller 13. The liquid jet 35 penetrates the paper web 3 and passes through the drying sieve 5 through. Torn out of the paper web Fiber particles and particles are from the Liquid jet 35 carried through the dryer. The mechanical load on the dry sieve is reduced to a minimum because not always the same area of revolving, endless Dryer screen hit by the liquid jet becomes. This is ensured by the fact that Cutting line more or less wavy in the Transitional area between the transfer strip 37 and the residual paper web 39 runs.

To the mechanical load on the dryer fabric 5 to a minimum, while at the same time Ensuring optimal cutting performance of the Tip cutter 15, the liquid jet 35, provided that it is supported by the dryer 5 Lane 3 hits with a pressure of 100 bar to 800 bar, preferably from 200 bar to 500 bar. Especially with a pressure range from 200 bar to 500 bar has shown that there is a safe separation between transfer strip 37 and residual web 39 results and that damage to the dryer wire 5 can be practically excluded, at least, when the machine is running, i.e. the dryer is moving and when the nozzle holder rotates.

It differs from the representation in FIG. 1 also possible to arrange the tip cutter 15 so that it acts on the web 3 in an area in which this on a roller, be it on a Drying cylinder 7 or 9 or on a web guide roller 13 rests. Here the pressure, under the liquid jet 35 from the individual nozzle 33 emerges in a range from 100 bar to 2000 bar are, preferably a pressure of 500 bar to 1500 bar selected.

The tip cutter 15 is preferably designed such that that the pressure under which the liquid jet 35 emerges from the single nozzle 33, depending from the point of impact to lane 3 and adjustable depending on their basis weight is. This ensures that the Tip cutter 15 can be used universally.

Finally, it should be noted that through the wavy course of the section line S die Contamination of the dryer fabric 5 respectively the surface of the rollers 7, 9 or 13 to a minimum is reduced. In addition, the mechanical and eroding stress on those struck by the beam Parts significantly reduced. Through the relative movement of the nozzle carrier results in addition to the high one Cutting performance a favorable cleaning effect of the liquid jet.

Figure 5 shows an embodiment of a cleaning device 102 trained beam device, which for cleaning one in the following as Dryer screen 104 designated dryer fabric belt in Area of a roller 106 of a not shown Paper machine is arranged. The cleaning device 102 can be used for any conveyor belt Paper or board making machine used be, for example for sieve belts or Felt a sieve or one Press or dryer section of a paper machine. The following is purely exemplary of dryer fabric conveyors a paper machine. The Cleaning device 102 includes one below Rotorduse designated as cleaning nozzle 108 a rotatable nozzle head 110, the one not nozzle arrangement shown. This nozzle arrangement can end one or more tangentially outflow Driving nozzles for generating a rotational movement in the range of 2000 to 3000 revolutions per minute and one or more Cleaning nozzles that the dryer wire 104 with a Apply cleaning medium.

Furthermore, here is an example of a cylindrical one Suction cup 114 provided the cleaning nozzle 108 and surrounds the nozzle head 110. The inner the suction cup 114 is in flow with one Suction line 116 connected, and forms one the suction space 118 assigned to the cleaning nozzle 108. The suction cup can also be oval, wherein the nozzle head 110 is also arranged eccentrically can be.

The cleaning device 102 comprises an energy chain for media supply, of which only a high-pressure hose that can be connected to a high-pressure pump 120 to supply the cleaning nozzle 108 with liquid in a pressure range of 100 bar to 1000 bar, preferably from 100 bar to 400 bar, in particular from 150 bar to 300 bar and the Suction line 116 for removing spray water or water mist with dirt particles present in it from the suction chamber 118 is shown.

The device components described so far of the cleaning device 102 are on a traversing trolley 111 in a direction transverse to the running direction of the dryer wire 104 is displaceably arranged. The traversing carriage 111 sits on cross beams 112 and is from a traversing motor, not shown can be driven at a specifiable speed, the traversing speed is usually is in the range of 0.3 m / min.

As can be seen from FIG. 5, a Dryer screen 104 facing end portion 122 of the Suction cup 114 of the circular cylindrical circumferential shape the roller 106 adapted so that between the suction cup 114 and the drying wire 104 a certain one adjustable distance or gap is guaranteed, the along the edge 124 of the end portion 122 in is essentially constant.

The arrangement of the cleaning device in the area the roller 106 has the following advantage: the stitches of the transport screen 104 are by the deflection widened on the roller so that the cleaning medium particularly easy in the tissue formation of the transport sieve penetrate and contaminants can remove very effectively.

In operation of the cleaning device 102, the Cleaning nozzle 108 or the nozzle arrangement in the nozzle head 110 via the high pressure hose 120 with a cleaning medium, preferably with pressurized water. The Nozzle head 110 with the arrangement of individual nozzles is due to the recoil effect of the propellant nozzle set in rotation. This describes the Liquid jet one at a certain angle to the longitudinal axis 126 of the cleaning nozzle conical path 127. It therefore falls below at an angle on the drying wire 104 and loose so the contaminants from its surface.

It is also possible to use a nozzle head 110 or several pivoted, an oscillating movement to provide single nozzles the during the traversing movement of the nozzle head 110 a band-shaped area of the dryer fabric 104 paint over.

By overlaying the traversing movement and the rotational or swiveling movement the dirt particles in different directions from the liquid jet of the nozzle arrangement hit and can be easily replaced than when using a parallel to the central axis 126 extending nozzle. Due to the inclination of the Nozzle head 110 or the nozzle arrangement is also caused that on the dryer fabric liquid jet hitting the suction chamber 118 is reflected, so that the resultant Water mist with dirt particles bound in it and residual water via the suction line 116 can be dissipated. There is one suction effect indicated by the arrows respectively Flow. Around the suction cup 114 therefore there is no splashing water, a dirt or Water leakage can thus be largely avoided become.

It has proven to be particularly advantageous if the negative pressure in the suction chamber 118 and the suction line 116 using a compressed air injector is produced. Furthermore, it has proven to be beneficial proven when the negative pressure in the suction space 118 is changeable and thus to different operating conditions can be adjusted.

The cleaning nozzle 108 or the individual Nozzles in the nozzle head 110 are for a pressure range from 100 bar to 1000 bar, preferably from Designed from 100 bar to 400 bar and have a nozzle diameter from 0.1 to 0.8 mm, preferably from 0.2 mm to 0.4 mm. Have proven themselves Pressure values from 150 bar to 300 bar and nozzle diameter from 0.2 mm to 0.4 mm. As nozzle material are diamond or ruby, preferably sapphire or ceramic materials used.

The cleaning device 102 is preferably so arranged that the cleaning medium to an area of the transport screen 104, which is very close is arranged on the surface of the deflecting roller. This ensures that the transport sieve when hitting the cleaning medium only deformed very little so that the energy lost very much is low. The cleaning device can also in Area of the incoming nip N can be arranged. This allows the overpressure in the area of the incoming Nips N support the suction effect of the suction chamber, so that detached particles are particularly effective dissipated from the surface of the transport sieve be, with at most very little cleaning medium emerges from the suction chamber.

From the above it is clear that with help the cleaning device conveyor belt described here a paper machine very thoroughly be cleaned, that is, disruptive particles from the nozzle head very effectively from the conveyor belt surface ablated. By the high Pressure of the medium emerging from the nozzles the particles practically shut off from the belt surface. Because of the relatively small diameter of the openings in the nozzles remains the required The amount of water is relatively low, which also means Swirling of dirt can be limited. The for the energy required to build the high pressure can be reduced with certain impurities, namely when the dirt particles through a wide stream of liquid not in the Conveyor belt surface are pressed. In these Cases can be liquid with a low Print in large quantities on the belt surface applied to wash off dirt particles.

Finally, it is also possible to use the liquids on the conveyor belts or their contamination adjust, for example, if necessary also use volatile liquids, so that rewetting of the paper web is avoided.

From what has been said above, it is also clear that for cleaning the conveyor belt surface Direction of impact of the cleaning medium is decisive is. Also a change of direction of the cleaning flow is very beneficial for loosening dirt particles. This can be done with the help of oscillating Nozzles can be reached. It is important that this cleaning effect possibly also without traversing the cleaning device can be done. In In this case, several will be spread across the width of the cleaning transport track distributed cleaning or Nozzle heads arranged each provided with at least one or more individual nozzles are.

Finally, it is pointed out that the Cleaning effect by changing the distance between nozzle and conveyor belt surface, a change the pressure of the cleaning agent and / or a change in the nozzle cross-section varies and various types of soiling and conveyor belt surfaces can be adjusted.

The shown in Figures 1 to 4 and 5 Beam equipment is common that one here Switching device, not shown, is provided with the help of which the pressure can be adjusted with the medium emerging from the jet device on the conveyor belt or on the Material web hits. Because of the switch it is possible to use the beam device both as a tip cutter as well as a cleaning device use. The one for use as a tailor required pressure is - depending on the single nozzle used - 200 to 300 bar less than him required when used as a cleaning device is. To ensure that the beam device can be used in a wide range of applications is, the switching device can Cause a pressure difference of 100 bar to 600 bar.

It is possible to switch a supply line assign over the one or more Nozzles of the jet device a liquid is fed. The one in the supply line Pressure can be changed using the switching device varies and thus to the use of the beam device be fitted.

It is also conceivable that the beam device several Nozzles, at least two individual nozzles, with different Has diameters with the switching device interact. With the help of the switching device can - with constant supply pressure - the single nozzle with the smaller one A liquid is applied to the diameter, if the beam device as a tip cutter is used. Accordingly, the single nozzle with the larger diameter with the supply pressure be applied, if the beam device serves as a cleaning device if so the liquid jet with a lower one Pressure should hit the conveyor belt.

From the above it is clear that when used the switching device described here Tip cutter also as a cleaning device can be used and a cleaning device can be used as a tip cutter. It is therefore no longer required, different beam devices to provide on the one hand a material web to cut inside a paper machine and on the other hand cleaning a conveyor belt sure. The space requirement within the paper machine is significantly reduced. The manufacturing as well Reduce maintenance costs significantly.

From the description of Figures 1 to 5 moreover clearly that the beam device too can have different nozzles, on the one hand for screen cleaning and on the other hand for that Cutting a material web are used. there a separate pressure supply can also be provided be the cleaning and cutting nozzles assigned. The switching device must then be so be trained that they each have the appropriate Pressure supply for cleaning or Cutting nozzles activated so that the jet device once as a cleaning device and once as a cutting device is usable. A more compact structure results, however, if the switching device, as described above, the supply lines or is assigned to nozzles and if only a single pressure supply for all nozzles of the Beam device is provided. The number of Utilities and switching facilities ultimately depends on the construction of the paper making machine from. It can in some cases be beneficial if over the length of the papermaking machine several pressure supply devices are provided, each with a Switching device are combined.

Claims (9)

1. Jet device (15; 102) for a machine for producing a material web (3), especially a paper or board web, having a nozzle device (17; 108) to discharge a liquid jet that is under pressure and aimed at the material web (3) and/or a transport belt (5; 104) that guides the material web (3), and having a changeover device with the aid of which the pressure at which the liquid jet impinges on the transport belt (5; 104) or on the material web (3) can be adjusted, it being possible for the jet device (15; 102) to be used at a first pressure of the liquid jet as a tail cutter for separating a strip from the material web (3) and, at a second pressure of the liquid jet, as a cleaning device for cleaning the transport belt (5; 104).
2. Jet device according to Claim 1, characterized in that the changeover device acts on at least one supply line via which the nozzle device (17; 108) is supplied with the liquid.
3. Jet device according to Claim 1, characterized in that the nozzle device (17; 108) has at least two individual nozzles of different diameter, which act together with the changeover device.
4. Jet device according to one of the preceding claims, characterized in that the nozzle device (17; 108) has a rotatable nozzle head (29; 110).
5. Jet device according to one of the preceding claims, characterized in that the nozzle device (17; 108) used is a tail cutter (15) which is used to separate a strip from a material web (3) moved by the transport belt (5).
6. Jet device according to one of the preceding Claims 1 to 4, characterized in that the nozzle device (17; 108) used is a cleaning device (102), which is used to clean a transport belt (104) of a machine for producing a material web (3), especially a paper or board web.
7. Use of a tail cutter (15), which has a nozzle device (17) for discharging a liquid jet under pressure and is used to separate a strip from a material web (3) moved by a transport belt (5; 104), as a device for cleaning a transport belt (5; 104) in a papermaking machine, the pressure at which the liquid jet impinges on the transport belt (5; 104) being adjusted appropriately by means of a changeover device.
8. Use of a cleaning device (102) which has a nozzle device (108) for discharging a liquid jet under pressure, for cleaning a transport belt (5; 104) in a machine for producing a material web (3), especially a paper or board web, as a tail cutter, the pressure at which the liquid jet impinges on the material web (3) being adjusted appropriately by means of a changeover device.
9. Jet device according to one of Claims 1 to 6, characterized in that the changeover device effects a difference between the first pressure and the second pressure of the liquid jet of 100 bar to 600 bar, preferably of 200 bar to 300 bar.

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