CA2546444A1 - Equipment and method for cutting of web and for cleaning of fabric in a web-forming machine - Google Patents
Equipment and method for cutting of web and for cleaning of fabric in a web-forming machine Download PDFInfo
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- CA2546444A1 CA2546444A1 CA 2546444 CA2546444A CA2546444A1 CA 2546444 A1 CA2546444 A1 CA 2546444A1 CA 2546444 CA2546444 CA 2546444 CA 2546444 A CA2546444 A CA 2546444A CA 2546444 A1 CA2546444 A1 CA 2546444A1
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- web
- fabric
- equipment
- forming machine
- nozzle
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B26—HAND CUTTING TOOLS; CUTTING; SEVERING
- B26F—PERFORATING; PUNCHING; CUTTING-OUT; STAMPING-OUT; SEVERING BY MEANS OTHER THAN CUTTING
- B26F3/00—Severing by means other than cutting; Apparatus therefor
- B26F3/004—Severing by means other than cutting; Apparatus therefor by means of a fluid jet
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B26—HAND CUTTING TOOLS; CUTTING; SEVERING
- B26F—PERFORATING; PUNCHING; CUTTING-OUT; STAMPING-OUT; SEVERING BY MEANS OTHER THAN CUTTING
- B26F3/00—Severing by means other than cutting; Apparatus therefor
- B26F3/004—Severing by means other than cutting; Apparatus therefor by means of a fluid jet
- B26F3/008—Energy dissipating devices therefor, e.g. catchers; Supporting beds therefor
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- Life Sciences & Earth Sciences (AREA)
- Forests & Forestry (AREA)
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Treatment Of Fiber Materials (AREA)
- Paper (AREA)
- Nonwoven Fabrics (AREA)
Abstract
The invention concerns equipment for cutting a web and for cleaning a fabric in a web-forming machine. The web-forming machine comprises a fabric (13) for supporting and transporting a web (14) formed on the machine. The equipment also comprises a high-pressure unit (17) and nozzle equipment (19) connected to it for forming a high-pressure water jet (23'). Furthermore, the equipment comprises support elements (18) for making the nozzle equipment (19) move in the cross direction of the web-forming machine, and water collection devices (22). The nozzle equipment (19) comprises one or more needle nozzles (23) for cutting the web (14) and for cleaning the fabric (13) using a single water jet (23'). The invention also concerns a method for cutting a web and for cleaning a fabric in a web-forming machine.
Description
EQUIPMENT AND METHOD FOR CUTTING OF WEB AND FOR CLEANING OF
FABRIC IN A WEB-FORMING MACHINE
The present invention concerns equipment for cutting a web and for cleaning a fabric in a web-forming machine, where the web-forming machine comprises a fabric for supporting and transporting the web formed on the machine, and where the equipment comprises:
- a high-pressure unit and nozzle equipment connected to it for forming a high-pressure water jet, - support elements for making the nozzle equipment move in the cross direction of the web-forming machine, - water collection devices, which are located essentially at the location of the nozzle equipment but on the other side of the fabric from the nozzle equipment, which is located on the same side of the fabric as the web, for both cutting the web against an unsupported fabric and for cleaning the fabric.
The invention also concerns a method for cutting a web and for cleaning a fabric in a web-forming machine.
In a web-forming machine, the web is cut for example in order to trim the edges of the web or to separate a threading tail from the web. The web is still moist at the beginning of web formation, so that air jets can be used for cutting. However, as the web dries, its strength increases. Water cutting is hence used often, with the web cut against a fabric using a water jet. The fabric becomes dirty during cutting, which is why separate cleaning equipment needs to be used. In known solutions, the cleaning equipment is placed on the upper cycle of the fabric at a point where there is no web.
The known solutions contain several drawbacks. Separate cleaning equipment is expensive, and it needs to be placed in a difficult environment in the upper part of the hood of the web-forming machine. The suction roll located close to the cutting point also becomes clogged, which causes runnability problems. Moreover, separate equipment is needed for cutting and cleaning, which means that for example double high-pressure pumps and support beams are needed.
Many of the said drawbacks can be avoided by using equipment presented in Finnish patent application 20040791. In the said equipment, a single nozzle arm contains two sets of nozzles connected to a single pressure water source. The first nozzles cut the web and the second nozzles clean the fabric. Water collection chutes are also located at location of the water jets. This solution avoids double equipment, because the same pressure water source can be used for both cutting the web and for cleaning the fabric. Furthermore, only one support beam is needed.
The nozzles can also be placed at the lower part of the hood, which facilitates maintenance and reduces the need to protect the equipment. The collection chutes also remove cutting waste from the web-forming machine.
Despite the improvements achieved, the said equipment still contains some drawbacks. The equipment contains several nozzles which require maintenance.
Furthermore, double water pipes with their own valves are needed in the equipment for different purposes. Two collection chutes are also needed, which is a problem in view of the confined location. The collection chutes have an open structure, so that water can spread to the environment despite the collection chutes.
The object of the present invention is to accomplish new type of equipment for cutting a web and for cleaning a fabric in a web-forming machine, where the equipment is simpler and more efficient than before. The characteristic features of the equipment according to the invention will be more fully understood from the enclosed patent claim 1. Another object of the present invention is to accomplish a new type of method for cutting a web and for cleaning a fabric in a web-forming machine, where the method can be applied easily in conjunction with different types of machines. The characteristic features of the method according to the invention will be more fully understood from the enclosed patent claim 7. The equipment and method according to the invention can be used for efficiently cleaning problematic locations in particular. Despite this, the cutting of the web fulfils the requirements set. In the method according to the invention, the equipment is used in a new and surprising way. Furthermore, the structure of the equipment is simple and contains but few components despite versatile functions. It is also easy to control the equipment. Moreover, cutting waste and water can be removed precisely and efficiently using water collection devices according to the invention.
In the following, the invention is described in more detail with reference to the accompanying drawings describing some applications of the invention, where:
.,. ......",..... ".4."..-" ix _...,. ~,.
FABRIC IN A WEB-FORMING MACHINE
The present invention concerns equipment for cutting a web and for cleaning a fabric in a web-forming machine, where the web-forming machine comprises a fabric for supporting and transporting the web formed on the machine, and where the equipment comprises:
- a high-pressure unit and nozzle equipment connected to it for forming a high-pressure water jet, - support elements for making the nozzle equipment move in the cross direction of the web-forming machine, - water collection devices, which are located essentially at the location of the nozzle equipment but on the other side of the fabric from the nozzle equipment, which is located on the same side of the fabric as the web, for both cutting the web against an unsupported fabric and for cleaning the fabric.
The invention also concerns a method for cutting a web and for cleaning a fabric in a web-forming machine.
In a web-forming machine, the web is cut for example in order to trim the edges of the web or to separate a threading tail from the web. The web is still moist at the beginning of web formation, so that air jets can be used for cutting. However, as the web dries, its strength increases. Water cutting is hence used often, with the web cut against a fabric using a water jet. The fabric becomes dirty during cutting, which is why separate cleaning equipment needs to be used. In known solutions, the cleaning equipment is placed on the upper cycle of the fabric at a point where there is no web.
The known solutions contain several drawbacks. Separate cleaning equipment is expensive, and it needs to be placed in a difficult environment in the upper part of the hood of the web-forming machine. The suction roll located close to the cutting point also becomes clogged, which causes runnability problems. Moreover, separate equipment is needed for cutting and cleaning, which means that for example double high-pressure pumps and support beams are needed.
Many of the said drawbacks can be avoided by using equipment presented in Finnish patent application 20040791. In the said equipment, a single nozzle arm contains two sets of nozzles connected to a single pressure water source. The first nozzles cut the web and the second nozzles clean the fabric. Water collection chutes are also located at location of the water jets. This solution avoids double equipment, because the same pressure water source can be used for both cutting the web and for cleaning the fabric. Furthermore, only one support beam is needed.
The nozzles can also be placed at the lower part of the hood, which facilitates maintenance and reduces the need to protect the equipment. The collection chutes also remove cutting waste from the web-forming machine.
Despite the improvements achieved, the said equipment still contains some drawbacks. The equipment contains several nozzles which require maintenance.
Furthermore, double water pipes with their own valves are needed in the equipment for different purposes. Two collection chutes are also needed, which is a problem in view of the confined location. The collection chutes have an open structure, so that water can spread to the environment despite the collection chutes.
The object of the present invention is to accomplish new type of equipment for cutting a web and for cleaning a fabric in a web-forming machine, where the equipment is simpler and more efficient than before. The characteristic features of the equipment according to the invention will be more fully understood from the enclosed patent claim 1. Another object of the present invention is to accomplish a new type of method for cutting a web and for cleaning a fabric in a web-forming machine, where the method can be applied easily in conjunction with different types of machines. The characteristic features of the method according to the invention will be more fully understood from the enclosed patent claim 7. The equipment and method according to the invention can be used for efficiently cleaning problematic locations in particular. Despite this, the cutting of the web fulfils the requirements set. In the method according to the invention, the equipment is used in a new and surprising way. Furthermore, the structure of the equipment is simple and contains but few components despite versatile functions. It is also easy to control the equipment. Moreover, cutting waste and water can be removed precisely and efficiently using water collection devices according to the invention.
In the following, the invention is described in more detail with reference to the accompanying drawings describing some applications of the invention, where:
.,. ......",..... ".4."..-" ix _...,. ~,.
FIG. 1 shows the principle of the equipment according to the invention on the dryer section of a web-forming machine;
FIG. 2 shows the equipment according to the invention seen from the side;
FIG. 3 shows a part of the equipment according to the invention seen from the machine direction;
FIG. 4a shows the principle of a function of the equipment according to the invention in the cleaning of a fabric;
FIG. 4b shows the principle of an alternative function of the equipment according to the invention in the cleaning of a fabric;
FIG. 4c shows the principle of another alternative function of the equipment according to the invention in the cleaning of a fabric.
FIG. 1 presents the principle of the equipment according to the invention in a web-forming machine. Paper and board machines are the most common web-forming machines. In FIG. 1, the dryer section comprises seven consecutive cylinder groups and 10', each with several drying cylinders 11 and vacuum rolls 12.
Furthermore, each cylinder group 10 and 10' comprises a dryer fabric as the fabric 13, with the fabric 13 running as an endless loop via drying cylinders 11 and vacuum rolls 12.
The fabric supports and transports the web formed on the web-forming machine.
For example when starting tail threading, the web is run down into the pulper before the dryer section. After successful tail threading, the web is spread to full width and run down to another pulper 16. When tail threading is continued, the tail is cut from the web using equipment located in the last cylinder group. The equipment can also be used for trim cutting the edge of the web.
On the dryer section, most fabrics are also provided with equipment for cleaning the fabric. Fabric washers of known type supply washing water to the fabric, and the washing water is then removed with the material that has come off the fabric.
However, the last cylinder group is an exception here, because the equipment is intended for cutting the web and for cleaning the fabric in the web-forming machine.
The overhead fabric washer is hence not needed in the last cylinder group 10' (FIG.
1 ). The basic components of the equipment include a high-pressure unit 17, the principle of which is presented in FIG. 1. In practice, the high-pressure unit comprises a high-pressure pump, which is connected to nozzle equipment for ",. .. ._........ . .1.,..,"~,. ., _, ..,...a..
FIG. 2 shows the equipment according to the invention seen from the side;
FIG. 3 shows a part of the equipment according to the invention seen from the machine direction;
FIG. 4a shows the principle of a function of the equipment according to the invention in the cleaning of a fabric;
FIG. 4b shows the principle of an alternative function of the equipment according to the invention in the cleaning of a fabric;
FIG. 4c shows the principle of another alternative function of the equipment according to the invention in the cleaning of a fabric.
FIG. 1 presents the principle of the equipment according to the invention in a web-forming machine. Paper and board machines are the most common web-forming machines. In FIG. 1, the dryer section comprises seven consecutive cylinder groups and 10', each with several drying cylinders 11 and vacuum rolls 12.
Furthermore, each cylinder group 10 and 10' comprises a dryer fabric as the fabric 13, with the fabric 13 running as an endless loop via drying cylinders 11 and vacuum rolls 12.
The fabric supports and transports the web formed on the web-forming machine.
For example when starting tail threading, the web is run down into the pulper before the dryer section. After successful tail threading, the web is spread to full width and run down to another pulper 16. When tail threading is continued, the tail is cut from the web using equipment located in the last cylinder group. The equipment can also be used for trim cutting the edge of the web.
On the dryer section, most fabrics are also provided with equipment for cleaning the fabric. Fabric washers of known type supply washing water to the fabric, and the washing water is then removed with the material that has come off the fabric.
However, the last cylinder group is an exception here, because the equipment is intended for cutting the web and for cleaning the fabric in the web-forming machine.
The overhead fabric washer is hence not needed in the last cylinder group 10' (FIG.
1 ). The basic components of the equipment include a high-pressure unit 17, the principle of which is presented in FIG. 1. In practice, the high-pressure unit comprises a high-pressure pump, which is connected to nozzle equipment for ",. .. ._........ . .1.,..,"~,. ., _, ..,...a..
forming a high-pressure water jet. The structure of the equipment is presented in more detail in conjunction with FIGS 2 and 3.
The equipment also comprises support elements 18 for making the nozzle equipment 19 move in the cross direction of the web-forming machine. Here, the support elements 18 comprise a support beam 20, onto which a carriage 21 with its nozzle equipment 19 is supported by means of guideways (FIG. 2). The support beam also comprises elements for moving the carriage at the desired speed and connections for supplying high-pressure water from the high-pressure unit to the nozzle equipment. Furthermore, the equipment comprises water collection devices 22, which are located essentially at the location of the nozzle equipment 19, but on a different side of the fabric 13 from the nozzle equipment 19. The structure of the water collection devices will be described in more detail below. In practice, the nozzle equipment 19 is located on the same side of the fabric 13 as the web 14. The web 14 is hence cut against an unsupported fabric 13. In other words, the water jet 23' can penetrate the fabric. The nozzle equipment 19 also cleans the fabric 13.
Unlike in known solutions, the nozzle equipment 19 according to the invention comprises one or more needle nozzles 23 in order to cut the web 14 and to clean the fabric 13 using a single water jet 23'. In other words, the fabric is cleaned using the same water jet that cuts the web, without changing the pressure or other settings of the equipment. The structure of the equipment is hence simple and its operation and control are uncomplicated. Due to the location of the equipment, cutting and cleaning are separate functions which exclude one another. In practice, cleaning is only possible when there is no web on the fabric. Such a situation occurs for example during a web break. At least part of the width of the fabric can also be cleaned during tail threading.
In conjunction with the cleaning of the fabric, the needle nozzles are in practice located essentially at a point in the cross direction of the web-forming machine which corresponds to the location of the water jet during the cutting of the web. In other words, the water jet cleans the fabric in the cross direction of the web-forming machine essentially at a point where the web is cut. This is in particular the case in conjunction with edge trimming, where a narrow area of the fabric becomes especially dirty. The cutting point may change occasionally, in which case the ..."....~~ ...~...~.~ ~..,w.~,.",.."..a.*.,".....",.,i~
cleaning point is also changed. Problems caused by the fouling of the fabric can hence be avoided. The preferred nozzle size of the needle nozzle is 0.05 - 0.4 mm.
Correspondingly, the pressure applied is 60 - 800 bar, preferably 200 - 400 bar. This provides a sufficiently efficient water jet for both cutting and cleaning.
Because a single nozzle and pressure is used, the size and shape of the water jet is always almost identical irrespective of whether the water jet is used for cutting or cleaning.
However, the needle nozzle is positioned and directed in accordance with the primary purpose of the water jet, i.e. cutting.
FIG. 2 shows a support beam 20 and a carriage 21 fitted on it. The carriage 21 comprises a nozzle arm 24, on which the nozzle equipment 19 is located. FIG. 2 also shows the water jet 23', which penetrates the fabric 13. On the opposite side of the fabric, there are water collection devices 22, which are only composed of a single collection chute 25. According to the invention, the collection chute 25 has a cross-sectional shape of a letter C, and the collection chute 25 is placed so that it opens towards the water jet 23'. The water can hence be collected in a controlled manner without the creation of adverse mist. Furthermore, the ends of the collection chute 25, which is located in the cross-direction of the web-forming machine, are lower in elevation than the middle point of the collection chute 25 (FIGS 4a -c).
Water hence runs by gravity to the ends of the collection chute 25, from where the water is taken further to waste water treatment. Moreover, at least part of the length of the collection chute 25 is provided with washing showers, which are shown in FIG. 2. The washing showers 26 can be arranged by means of a washing pipe 27 placed at the upper edge of the collection chute 25, with the washing pipe 27 having suitable holes 28 for washing water (FIG. 3). Here, the washing pipe extends over the entire length of the collection chute. Correspondingly, the collection chute extends over the entire width of the web-forming machine. FIG. 3 also shows a first connection 29 for supplying washing water into the washing pipe 27 and a second connection 30 for discharging washing water from the collection chute 25. The collection chute 25 is supported by its ends by means of a support structure 35 and at the middle to an existing suction box 31. In new web-forming machines, the collection chute can be integrated as part of the suction box or other nearby structure.
..", .. . ..,...,., ... . " 4.. ,.-1a.-... "~ .,~..
For reasons of clarity, FIG. 3 shows the carriage 21 detached. The nozzle arm fastened to the carriage 21 contains nozzle equipment 19, which comprises here one high-pressure needle nozzle 23. There is also a disc 32 around the needle nozzle 23 in order to avoid damage if the fabric hits the nozzle equipment.
Due to the novel way of operation, only a single pressure water line 33 is needed by the equipment. The travel direction of the carriage 21 is indicated by the two-head arrow in FIG. 3.
In addition to the equipment, the present invention concerns a method for cutting a web and for cleaning a fabric in a web-forming machine. In the method, a high-pressure water jet is formed, and the water jet is moved in the cross direction of the web-forming machine. The web is cut with the water jet, and the fabric is also cleaned with the water jet. At the same time, water is collected on the opposite side of the fabric essentially at the location of the water jet. According to the invention, the water jet is formed by means of one or more needle nozzles. In addition to cutting the web, the fabric is cleaned with the same single water jet. In practice, the fabric is cleaned with the water jet when the fabric has no web, for example during a web break. A separate break washer is hence not needed.
During a web break, the fabric can be cleaned across its entire width. Due to the narrow water jet, there is in practice enough time to clean only a part of the fabric especially during short breaks. In these cases, the principle described above is applied, i.e. an area where the web has been cut earlier is cleaned. The efficient but narrow water jet can hence be directed correctly. In the third function, the fabric is cleaned simultaneously at two locations, preferably independently of each other. For this purpose, the nozzle equipment 19 includes at least two needle nozzles 23 installed in two separate nozzle units 34, which are functionally separate from each other (FIGS 4a - c). The web can hence be cut or the fabric can be cleaned at two locations simultaneously. A sufficient cleaning efficiency is achieved in particular.
FIGS 4a - c present various cleaning methods. In FIG. 4a, a single nozzle unit cleans the fabric 13 essentially across its entire width. In FIG. 4b, the fabric 13 is only cleaned over a narrow area at which the web has been cut earlier. FIG. 4c shows the use of two independent nozzle units 34 for cleaning. The left-hand side nozzle unit 34 cleans the left side of the fabric 13 while the right-hand side nozzle """ .,."".., "w",."~".~ ,",", unit 34 cleans a narrow area on the right-hand side edge of the fabric 13. In practice, the functions can be combined and varied as necessary.
In the cleaning of the fabric in particular, the needle nozzle is moved in the cross direction of the web-forming machine at a speed according to the invention, which is 0.3 - 3 per mil of the travel speed of the fabric. For example, if the carriage is moved one millimeter per second during a web break of 15 minutes, a cleaned area of almost one meter in width is achieved when the travel speed of the fabric is 1,800 meters per minute. By moving the carriage just a little faster than this and especially by using two independent nozzle units, the entire width of the fabric can be cleaned even during a short break. The equipment is preferably placed so that cleaning is started automatically during breaks.
The equipment according to the invention can be placed easily in conjunction with the fabric. The control of the equipment is also easy despite versatile functions.
Unnecessary equipment and components can be avoided when using the method, and sufficient cleaning efficiency is still achieved. Furthermore, water consumption is reduced, and water can be removed from the web-forming machine in a controlled manner.
The equipment also comprises support elements 18 for making the nozzle equipment 19 move in the cross direction of the web-forming machine. Here, the support elements 18 comprise a support beam 20, onto which a carriage 21 with its nozzle equipment 19 is supported by means of guideways (FIG. 2). The support beam also comprises elements for moving the carriage at the desired speed and connections for supplying high-pressure water from the high-pressure unit to the nozzle equipment. Furthermore, the equipment comprises water collection devices 22, which are located essentially at the location of the nozzle equipment 19, but on a different side of the fabric 13 from the nozzle equipment 19. The structure of the water collection devices will be described in more detail below. In practice, the nozzle equipment 19 is located on the same side of the fabric 13 as the web 14. The web 14 is hence cut against an unsupported fabric 13. In other words, the water jet 23' can penetrate the fabric. The nozzle equipment 19 also cleans the fabric 13.
Unlike in known solutions, the nozzle equipment 19 according to the invention comprises one or more needle nozzles 23 in order to cut the web 14 and to clean the fabric 13 using a single water jet 23'. In other words, the fabric is cleaned using the same water jet that cuts the web, without changing the pressure or other settings of the equipment. The structure of the equipment is hence simple and its operation and control are uncomplicated. Due to the location of the equipment, cutting and cleaning are separate functions which exclude one another. In practice, cleaning is only possible when there is no web on the fabric. Such a situation occurs for example during a web break. At least part of the width of the fabric can also be cleaned during tail threading.
In conjunction with the cleaning of the fabric, the needle nozzles are in practice located essentially at a point in the cross direction of the web-forming machine which corresponds to the location of the water jet during the cutting of the web. In other words, the water jet cleans the fabric in the cross direction of the web-forming machine essentially at a point where the web is cut. This is in particular the case in conjunction with edge trimming, where a narrow area of the fabric becomes especially dirty. The cutting point may change occasionally, in which case the ..."....~~ ...~...~.~ ~..,w.~,.",.."..a.*.,".....",.,i~
cleaning point is also changed. Problems caused by the fouling of the fabric can hence be avoided. The preferred nozzle size of the needle nozzle is 0.05 - 0.4 mm.
Correspondingly, the pressure applied is 60 - 800 bar, preferably 200 - 400 bar. This provides a sufficiently efficient water jet for both cutting and cleaning.
Because a single nozzle and pressure is used, the size and shape of the water jet is always almost identical irrespective of whether the water jet is used for cutting or cleaning.
However, the needle nozzle is positioned and directed in accordance with the primary purpose of the water jet, i.e. cutting.
FIG. 2 shows a support beam 20 and a carriage 21 fitted on it. The carriage 21 comprises a nozzle arm 24, on which the nozzle equipment 19 is located. FIG. 2 also shows the water jet 23', which penetrates the fabric 13. On the opposite side of the fabric, there are water collection devices 22, which are only composed of a single collection chute 25. According to the invention, the collection chute 25 has a cross-sectional shape of a letter C, and the collection chute 25 is placed so that it opens towards the water jet 23'. The water can hence be collected in a controlled manner without the creation of adverse mist. Furthermore, the ends of the collection chute 25, which is located in the cross-direction of the web-forming machine, are lower in elevation than the middle point of the collection chute 25 (FIGS 4a -c).
Water hence runs by gravity to the ends of the collection chute 25, from where the water is taken further to waste water treatment. Moreover, at least part of the length of the collection chute 25 is provided with washing showers, which are shown in FIG. 2. The washing showers 26 can be arranged by means of a washing pipe 27 placed at the upper edge of the collection chute 25, with the washing pipe 27 having suitable holes 28 for washing water (FIG. 3). Here, the washing pipe extends over the entire length of the collection chute. Correspondingly, the collection chute extends over the entire width of the web-forming machine. FIG. 3 also shows a first connection 29 for supplying washing water into the washing pipe 27 and a second connection 30 for discharging washing water from the collection chute 25. The collection chute 25 is supported by its ends by means of a support structure 35 and at the middle to an existing suction box 31. In new web-forming machines, the collection chute can be integrated as part of the suction box or other nearby structure.
..", .. . ..,...,., ... . " 4.. ,.-1a.-... "~ .,~..
For reasons of clarity, FIG. 3 shows the carriage 21 detached. The nozzle arm fastened to the carriage 21 contains nozzle equipment 19, which comprises here one high-pressure needle nozzle 23. There is also a disc 32 around the needle nozzle 23 in order to avoid damage if the fabric hits the nozzle equipment.
Due to the novel way of operation, only a single pressure water line 33 is needed by the equipment. The travel direction of the carriage 21 is indicated by the two-head arrow in FIG. 3.
In addition to the equipment, the present invention concerns a method for cutting a web and for cleaning a fabric in a web-forming machine. In the method, a high-pressure water jet is formed, and the water jet is moved in the cross direction of the web-forming machine. The web is cut with the water jet, and the fabric is also cleaned with the water jet. At the same time, water is collected on the opposite side of the fabric essentially at the location of the water jet. According to the invention, the water jet is formed by means of one or more needle nozzles. In addition to cutting the web, the fabric is cleaned with the same single water jet. In practice, the fabric is cleaned with the water jet when the fabric has no web, for example during a web break. A separate break washer is hence not needed.
During a web break, the fabric can be cleaned across its entire width. Due to the narrow water jet, there is in practice enough time to clean only a part of the fabric especially during short breaks. In these cases, the principle described above is applied, i.e. an area where the web has been cut earlier is cleaned. The efficient but narrow water jet can hence be directed correctly. In the third function, the fabric is cleaned simultaneously at two locations, preferably independently of each other. For this purpose, the nozzle equipment 19 includes at least two needle nozzles 23 installed in two separate nozzle units 34, which are functionally separate from each other (FIGS 4a - c). The web can hence be cut or the fabric can be cleaned at two locations simultaneously. A sufficient cleaning efficiency is achieved in particular.
FIGS 4a - c present various cleaning methods. In FIG. 4a, a single nozzle unit cleans the fabric 13 essentially across its entire width. In FIG. 4b, the fabric 13 is only cleaned over a narrow area at which the web has been cut earlier. FIG. 4c shows the use of two independent nozzle units 34 for cleaning. The left-hand side nozzle unit 34 cleans the left side of the fabric 13 while the right-hand side nozzle """ .,."".., "w",."~".~ ,",", unit 34 cleans a narrow area on the right-hand side edge of the fabric 13. In practice, the functions can be combined and varied as necessary.
In the cleaning of the fabric in particular, the needle nozzle is moved in the cross direction of the web-forming machine at a speed according to the invention, which is 0.3 - 3 per mil of the travel speed of the fabric. For example, if the carriage is moved one millimeter per second during a web break of 15 minutes, a cleaned area of almost one meter in width is achieved when the travel speed of the fabric is 1,800 meters per minute. By moving the carriage just a little faster than this and especially by using two independent nozzle units, the entire width of the fabric can be cleaned even during a short break. The equipment is preferably placed so that cleaning is started automatically during breaks.
The equipment according to the invention can be placed easily in conjunction with the fabric. The control of the equipment is also easy despite versatile functions.
Unnecessary equipment and components can be avoided when using the method, and sufficient cleaning efficiency is still achieved. Furthermore, water consumption is reduced, and water can be removed from the web-forming machine in a controlled manner.
Claims (12)
1.Equipment for cutting a web and for cleaning a fabric in a web-forming machine, where the web-forming machine comprises a fabric (13) for supporting and transporting the web (14) formed on the machine, and where the equipment comprises:
- a high-pressure unit (17) and nozzle equipment (19) connected to it for forming a high-pressure water jet (23'), - support elements (18) for making the nozzle equipment (19) move in the cross direction of the web-forming machine, - water collection devices (22), which are located essentially at the location of the nozzle equipment (19) but on the other side of the fabric (13) from the nozzle equipment (19), which is located on the same side of the fabric (13) as the web (14), for both cutting the web (14) against an unsupported fabric (13) and for cleaning the fabric (13).
characterized in that the nozzle equipment (19) comprises one or more needle nozzles (23) for cutting the web (14) and for cleaning the fabric (13) using a single water jet (23').
- a high-pressure unit (17) and nozzle equipment (19) connected to it for forming a high-pressure water jet (23'), - support elements (18) for making the nozzle equipment (19) move in the cross direction of the web-forming machine, - water collection devices (22), which are located essentially at the location of the nozzle equipment (19) but on the other side of the fabric (13) from the nozzle equipment (19), which is located on the same side of the fabric (13) as the web (14), for both cutting the web (14) against an unsupported fabric (13) and for cleaning the fabric (13).
characterized in that the nozzle equipment (19) comprises one or more needle nozzles (23) for cutting the web (14) and for cleaning the fabric (13) using a single water jet (23').
2.Equipment according to claim 1, characterized in that in conjunction with the cleaning the fabric (13), the needle nozzles (23) are located essentially at a point in the cross direction of the web-forming machine which corresponds to the location of the water jet (23') during the cutting of the web (14).
3.Equipment according to claim 1 or 2, characterized in that the nozzle size of the needle nozzle (23) is 0.05 - 0.4 mm.
4.Equipment according to any claim 1 - 3, characterized in that the nozzle equipment (19) comprises at least two needle nozzles (23) installed in two separate nozzle units (34), which are functionally separate from each other, for cutting the web or for cleaning the fabric at two different locations simultaneously.
5.Equipment according to any claim 1 - 4, characterized in that the water collection devices (22) comprise one collection chute (25), which has a cross-sectional shape of a letter C, and where the collection chute (25) opens towards the water jet (23').
6.Equipment according to claim 5, characterized in that the ends of the collection chute (25), which is located in the cross-direction of the web-forming machine, are lower in elevation than the middle point of the collection chute (25), or at least washing showers (26) are provided along some of the length of the collection chute (25).
7.Method for cutting a web and for cleaning a fabric in a web-forming machine, where the web-forming machine comprises a fabric (13) for supporting and transporting the web (14) formed on the machine, and where the method is used for forming a high-pressure water jet (23'), which is moved in the cross direction of the web-forming machine, and the web (14) is cut with the water jet (23') against an unsupported fabric (13) on the same side of the fabric (13) as the web (14), and at the same time water is collected from the opposite side of the fabric (13) essentially at the location of the water jet (23'), characterized in that the water jet (23') is formed with one or more needle nozzles (23), and in addition to the cutting of the web (14), the fabric (13) is cleaned using the same water jet (23').
8.Method according to claim 7, characterized in that the fabric (13) is cleaned with the water jet (23'), when the fabric (13) is without a web (14).
9.Method according to claim 7 or 8, characterized in that the fabric (13) is cleaned with the water jet (23') essentially at a point in the cross direction of the web-forming machine where the web (14) is cut.
10.Method according to any claim 7 - 9, characterized in that the fabric (13) is cleaned simultaneously at two locations, preferably independently of each other.
11.Method according to any of the claims 7 - 10, characterized in that the needle nozzle (23) is moved in the cross direction of the web-forming machine at a speed which is 0.3 - 3 per mil of the travel speed of the fabric (13).
12.Method according to any of the claims 7 - 11, characterized in that the needle nozzle (23) is located in conjunction with the last cylinder group (10') of the cylinder groups (10) included in the web-forming machine.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FI20055443 | 2005-08-23 | ||
| FI20055443A FI20055443A (en) | 2005-08-23 | 2005-08-23 | Apparatus Test and Method for Cutting the Web and Reopening the Tissue in a Web Forming Machine |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2546444A1 true CA2546444A1 (en) | 2007-02-23 |
Family
ID=34896342
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2546444 Abandoned CA2546444A1 (en) | 2005-08-23 | 2006-05-12 | Equipment and method for cutting of web and for cleaning of fabric in a web-forming machine |
Country Status (3)
| Country | Link |
|---|---|
| CA (1) | CA2546444A1 (en) |
| DE (1) | DE102006028265A1 (en) |
| FI (1) | FI20055443A (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101804601B (en) * | 2010-04-21 | 2011-11-02 | 重庆大学 | High-pressure water jet cutting and positioning device |
-
2005
- 2005-08-23 FI FI20055443A patent/FI20055443A/en not_active IP Right Cessation
-
2006
- 2006-05-12 CA CA 2546444 patent/CA2546444A1/en not_active Abandoned
- 2006-06-20 DE DE200610028265 patent/DE102006028265A1/en not_active Withdrawn
Also Published As
| Publication number | Publication date |
|---|---|
| DE102006028265A1 (en) | 2007-03-01 |
| FI20055443A0 (en) | 2005-08-23 |
| FI20055443A (en) | 2007-02-24 |
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| Date | Code | Title | Description |
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| FZDE | Dead |