Patent Publication Number: US-2020298153-A1

Title: System and related methods for fabrication of wire based screen filters

Description:
FIELD OF THE DISCLOSURE 
     The present disclosure relates to a screen filter fabrication machine for fabricating wire based screen filters for separating solid matter from fluid streams. More particularly, the present disclosure is directed to a screen filter fabrication machine having a control system configured to monitor one or more parameters and implement one or more process control adjustments to affect a more uniform slot width between wires. 
     BACKGROUND OF THE DISCLOSURE 
     Screens fabricated from welded wires have been utilized for a variety of purposes since early in the 20th century. One of the most popular uses has been as a liquid separation instrument or filter to remove solids from liquids or as a gas separation instrument for removing solids or suspended liquids from gases. Representative liquids can include fresh or salt water as well as various aqueous and non-aqueous liquid process streams found in a variety of industries. More recently, wire-based screens have even been utilized as architectural components so as to provide unique aesthetic appearances to the exterior of buildings and other public structures. Regardless of the particular use, the fabrication techniques are similar for screens in each of these applications. 
     In the context of solid/liquid separation, one frequent application for wire-based screen filters is as part of a water intake system. These water intake systems typically use an inlet pipe adapted to transport water from a position submerged in a body of water to the end-user adjacent to the body of water. An inlet pipe is submerged in the body of water and the end of the inlet pipe is typically coupled to an intake filter assembly configured to inhibit waterborne debris and aquatic life, of a certain size, from entering the inlet pipe. Water intake systems are typically used to provide water to end-users such as manufacturing plants, cities, irrigation systems, and power generation facilities located adjacent to a body of water such as a river, lake, or salt water bodies. The end user may employ this type of system as an alternative to drilling a well or buying water from a municipality. Additionally, use of these systems may be determined by the location of the end-user, for example remote locations where water from a municipal source and/or electrical power to operate pumps is not readily available. These water collection systems have the ability to adapt to various conditions and deliver water efficiently and economically. 
     In many water intake systems, the inlet pipe will include an intake filter assembly that incorporates a wire-based screen to prevent particulate matter from entering the water intake system. Due to their robust strength, the wire-based screen allows the intake filter assembly to be repeatably cleaned, backwashed and or flushed so as to extend the life of the intake filter assembly. As such, costs associated with plugging, replacement and disposal common to other types of intake filters, such as conventional bag, cartridge, ceramic, hollow fiber, and membrane filters, can be avoided. These same advantages extend to the use of wire-based screens in industrial processes, which can lead to increase process uptime and lower production costs. 
     While the current state of the art in wire-based screens provides a number for many processing advantages, it would be advantageous to further improve upon the manufacturing techniques so as to improve screen consistency and reduce production waste. In particular, it would be advantageous to develop techniques that provide for the manufacturing of wire-based screens having reduced variability during construction such that variability in gap width between adjacent wires is reduced. 
     SUMMARY OF THE INVENTION 
     Embodiments of the present disclosure provide a screen filter fabrication machine configured to fabricate a screen filter with a higher level of consistency in gap width, such that the filter can be used to target and/or remove particulate matter having above a desired particulate size that is greater than the gap opening. One representative embodiment of the present disclosure provides a screen filter fabrication machine including a frame, a tooling head configured to rotate relative to the frame and retain a plurality of support rods, a wire feed wheel operably coupled to the frame and configured to dispense wire, and a control system configured to monitor one or more parameters concerning the slot width, and implement one or more process control adjustments configured to enable the winding of the wire around the plurality of support rods in such a manner that at least 99.7% of a measured slot width during screen filter fabrication falls within three standard deviations of a mean slot width measured during screen filter fabrication. 
     The above summary is not intended to describe each illustrated embodiment or every implementation of the subject matter hereof. The figures and the detailed description that follow more particularly exemplify various embodiments. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
       Subject matter hereof may be more completely understood in consideration of the following detailed description of various embodiments in connection with the accompanying figures, in which: 
         FIG. 1  is a perspective, end view depicting a screen filter in accordance with an embodiment of the disclosure. 
         FIG. 2  is an end view depicting the screen filter of  FIG. 1 . 
         FIG. 3  is a partial, cross-sectional view depicting a screen filter in accordance with an embodiment of the disclosure. 
         FIG. 4A  is a partial, profile view depicting a spiral wrapping of wire in the form of a cylindrical body in accordance with an embodiment of the disclosure. 
         FIG. 4B  is a partial, perspective view depicting a spiral wrapping of wire in the form of a cylindrical body in accordance with an embodiment of the disclosure. 
         FIG. 5  is a schematic view depicting a screen filter fabrication machine in accordance with an embodiment of the disclosure. 
         FIG. 6  is a schematic view depicting an alternative embodiment of a screen filter fabrication machine in accordance with the disclosure. 
         FIG. 7  is a process flow diagram for actively monitoring and controlling a slot width of a screen filter during fabrication in accordance with an embodiment of the disclosure. 
         FIG. 8  is a schematic for a fabrication machine performing the process of  FIG. 7  in accordance with an embodiment of the disclosure. 
         FIG. 9  is a bell curve illustrating a normal distribution of a monitored slot width along a length of cylindrical body of a screen filter in accordance with an embodiment of the disclosure. 
     
    
    
     While various embodiments are amenable to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawings and will be described in detail. It should be understood, however, that the intention is not to limit the claimed inventions to the particular embodiments described. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the subject matter as defined by the claims. 
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to  FIGS. 1 and 2 , a screen filter  100  is depicted in accordance with an embodiment of the disclosure. In one embodiment, the screen filter  100  can be fabricated to assume a cylindrical body  101 . Alternatively, the screen filter  100  can be fabricated so as to assume a flat screen, whereby two or more flat screens can be operably coupled to assume other geometric configurations. Screen filter  100  is generally fabricated from suitable metallic materials and alloys including, for example, stainless steel, titanium, copper-nickel alloys, and the like. Material selection can be dependent on compatibility characteristics with a fluid to be filtered or based upon other process variables. Other nonmetallic materials including, for example, PVC, that have properties enabling fabrication with similar geometries having similar gap widths and precision can also be used in potential embodiments of the disclosure. 
     In one embodiment, the screen filter  100  can include a plurality of support rods  102 . The support rods  102  can be evenly spaced and arranged in parallel relation to a longitudinal axis  104  of the screen filter  100 . As best depicted in  FIG. 2 , each support rod  102  can include an interior surface  106  and an exterior surface  108 , so as to define a support rod height  140  there between. A continuous length of wire  110  can be wound about the support rods  102 , such that the wire  110  can be affixed to the exterior surface  108  at each point of contact  112 . As the wire is continually wound and spiraled about the support rods  102 , the cylindrical body  101  is generally defined for the screen filter  100 . 
     Referring to  FIG. 3 , a section view of a screen filter  100  is depicted in accordance with an embodiment of the disclosure. In one embodiment, the wire  110  has a triangular cross section  120 , commonly referred to in the industry as Vee-Wire®. While wire  110  having a triangular cross section  120  is preferred, the use of other conventional wire profiles known in the art is also contemplated. As depicted, the wire  110  can have a first vertex  122  affixed to the support rod  102  at the point of contact  112 . The first vertex  122  can be operably coupled to the support rod  102  using a suitable technique, such as electrical resistance welding, ultrasonic bonding or other fusing/attachment methods known in the art. As the weld is completed at each point of contact  112 , a penetration depth  123  is defined in the wire  110  and/or support rod  102 . 
     Opposite to the first vertex  122 , is an exposed wire surface  124  having a wire width  114  defined between a second vertex  126  and a third vertex  128 . The second vertex  126  and the third vertex  128  can each define a corner radius  130 . A pair of relief surfaces  132   a ,  132   b  can extend between the first vertex  122  and the second and third vertices  126 ,  128  respectively. A wire height  136  can be defined between the first vertex  122  and the exposed wire surface  124 . When the wire  110  is operably coupled to the support rod  102 , and overall screen height  138  is generally defined between the interior surface  106  and the exposed wire surface  124 . The screen height  138  is generally equivalent to the sum of the wire height  136  and the support rod height  140 , minus the penetration depth  123 . The spiral wrapping and welding of the wire  110  about the support rods  102  results in a repeating pattern of adjacent wires  110   a ,  110   b.    
     Referring to  FIGS. 4A-B , for improved clarity, a portion of the spiral wrapping of wire  110  in the form of a cylindrical body  101  is depicted without the support rods. In forming the cylindrical body  101 , the wire  110  can be wound around the support rods  102  at a given pitch  116 , so as to define a slot having a measurable slot width  118 . As best depicted in  FIG. 3 , the slot width  118  can be defined between the opposing corner radii  130  of adjacent wires  110   a ,  110   b , whereas the pitch can defined between the same corner radii  130  of adjacent wires  110   a ,  110   b.    
     In some embodiments, it may be desirable to “reverse” the attachment of the wire  110  to the support rod  102 , such that the exposed wire surface  124  is affixed to the support rod  102  such that the slot width  118  is defined proximate to the support rod  102  and is inwardly facing toward a center of the cylindrical body  101 . Additionally, depending upon the overall size of the screen filter  100 , for example, the desired diameter and/or length of the cylindrical body  101 , the wire  110  can comprise two more lengths or spools of wire  110  that have been joined together, such that the spiral winding of the wire  110  about the support rods  102  is continuous. In some embodiments, the cylindrical body  101  can be cut, sheared or otherwise reformed into a flat screen or into other alternative screen shapes. In addition, the screen filter  100  can include additional attachment or framing elements such as, for example, rings, fittings, bards, and other like devices to aid in mounting the screen filter  100  and the desired application. 
     In some embodiments, the pitch  116  and/or penetration depth  123  of the wire  110  can be varied during fabrication to achieve a more uniform slot width  118 . For example, in one embodiment, one or more quality control measurements can be taken during the fabrication process, and used to provide feedback in the control and positioning of adjacent wires  110   a ,  110   b , and/or the attachment of the wire  110  to the support rod  102 , so as to reduce the maximum deviation along the slot width  118  within a cylindrical body  101 . Accordingly, the screen filter  100  of the present disclosure is generally fabricated such that the slot width  118  is uniform and consistently defined between each of the adjacent wires  110   a ,  110   b  along a length of the cylindrical body  101 . In some embodiments, consistency in the measurable slot width  118  can be such that the screen filter  100  can reliably be used to remove particulate matter having a particulate size of 10 μm or less. 
     In some embodiments, it may be desirable to vary a “tilt” of the wire  110  relative to the support rods  102 . In these situations, the exposed wire surface  124  between adjacent wraps of the wire  110  will not reside in the same plane intentionally, nor will they be parallel to plane of the support rods  102 . In some instances, the exposed wire surface  124  between adjacent wraps of wire  110  will reside in a parallel orientation. It will be understood that depending upon the specific design of screen filter  100 , the “tilt” of the wire  110  may be intentionally varied throughout the construction of a single screen filter  100 . 
     Referring to  FIG. 5 , a screen filter fabrication machine  200 , configured to fabricate screen filters  100 , is depicted in accordance with an embodiment of the disclosure. The screen filter fabrication machine  200  can include a frame  202  and a tooling head  204  configured to hold a plurality of supporting rods  102  and rotate relative to the frame  202  as the wire  110  is wound around the supporting rods  102  during the fabrication process. In one embodiment, rotation of the tooling head  204  can be powered by a motor  206 , either directly or via a mechanical gear assembly  208 . The tooling head  202  can be supported at an end opposite by a tailstock bearing assembly  210 . 
     The plurality of supporting rods  102  can be operably coupled to the tooling head  204  via a pull ring  214 , such that the pull ring  214  is configured to pull the supporting rods  102  through the screen filter fabrication machine  200 , as the wire  110  is wound around the supporting rods  102 . Prior to being wound with wire  110 , the plurality of supporting rods  102  can be supported by a rod holder  216 . A wire feed wheel  218  can be positioned in proximity to the tooling head  204 , and can be configured to dispense wire  110  as it is wound around the supporting rods  102 . A wire feed guide  220  can further aid in positioning the wire  110  relative to the supporting rods  102  during fabrication. In some embodiments, the tension of wire  110  can be controlled via the wire feed wheel  218 , as it is wound around the supporting rods  102 , so as to affect the proper penetration depth  123  of the wire  110  relative to the supporting rods  102 . 
     In some embodiments, an electrical current generated by an electrical current source  222  can be applied to the wire  110 , while the plurality of supporting rods  102  can be in electrical communication with an electrical ground. Accordingly, in some embodiments, the electrical current applied to wire  110  can cause the wire  110  to bond to one of the plurality of supporting rods  102  when the wire  110  and the supporting rod  102  make contact, thereby causing the wire  110  to fuse or to be welded to the supporting rod  102 . In some embodiments, only the supporting rod  102  closest to the wire feed guide  222  can be grounded, so as to establish a clear path of least resistance. In some embodiments, the electrical current can be alternated on and off, such that electrical current is only applied when needed. In some embodiments, the magnitude of electrical current can be controlled by the electrical current source  222 , so as to affect the proper penetration depth  123  of the wire  110  relative to the supporting rods  102 . 
     In some embodiments, the tooling head  204  can be configured to move laterally along the axis of rotation relative to the frame  202 , so as to provide the proper pitch  116  between adjacent wires  110   a ,  110   b  as the wire  110  is wound around the supporting rods  102 . In one embodiment, a rotary screw  212  is employed to affect the lateral movement; however, the use of other mechanisms known in the art to affect lateral movement is also contemplated. In one embodiment, the lateral movement of the tooling head  204  relative to the frame  202  can be controlled, so as to achieve the desired slot width  118  between adjacent wires  110   a ,  110   b . Additionally, in one embodiment, the rotation of the tooling head  204  relative to the frame  202  can be controlled, so as to achieve the desired penetration depth  123  of the wire  110  relative to the supporting rods  102  and/or the desired slot width  118  between adjacent wires  110   a ,  110   b  during the fabrication process. 
     Referring to  FIG. 6 , in an alternative embodiment of a screen filter fabrication machine  200 ′, rather than laterally shifting the tooling head  202  relative to the frame  202 , the wire feed wheel  218  and wire feed guide  220  can be configured to shift laterally relative to the frame  202 . In this embodiment, at least one of the rotation of the tooling head  204 , the magnitude of electrical current via the electrical current source  222 , the tension of wire  110  via the wire feed wheel  218 , and the lateral position of the wire feed wheel  218  and wire feed guide  220  can be controlled, so as to achieve the desired penetration depth  123  of the wire  110  relative to the supporting rods  102  and/or the desired slot width  118  between adjacent wires  110   a ,  110   b  during the fabrication process. 
     Referring again to  FIG. 5 , in one embodiment, the screen filter fabrication machine, can include a control system  224 , having a display  226 , a computer  228  operably coupled to and in communication with one or more sensors configured to monitor one or more parameters concerning the slot width, and a storage unit  230  configured to store information or data gathered by the one or more sensors. Computer  228  generally comprises a suitable processor and operating system while storage unit  230  includes memory appropriate for interfacing with the computer processor. 
     Referring to  FIG. 7 , a process  300  for actively monitoring and controlling the slot width  118  during the fabrication of a screen filter  100  is depicted in accordance with an embodiment of the disclosure. At  302 , the screen filter fabrication machine  200  is initialized. Fabrication machine  200  is loaded with the appropriate number of supporting rods  102  and wire  110  for fabrication of a screen filter  100 . At  304 , the fabrication machine  200  begins fabricating the screen filter  100 , by rotating the tooling head  204  to affect winding of the wire  110  around the plurality of supporting rods  102 . 
     At  306 , during fabrication, one or more parameters concerning the quality of the screen filter  100 , or components thereof, are sensed or monitored. In one embodiment, the parameters concerning the quality of the screen filter  100  include at least one of the (1) wire width  114 , (2) pitch  116 , (3) slot width  118 , (4) rate of advance (e.g., lateral shift of the tooling head  202  and/or wire feed wheel  218  relative to the frame  202 ), (5) magnitude of the weld energy (e.g., electrical current supplied via the electrical current source  222 ), (6) weld pressure (e.g., tension in the wire  110  affected by the wire feed wheel  218  and/or the rotation of the tooling head  204  relative to the frame  202 ), (7) linear position of the tooling head  204  and/or wire feed wheel  218  relative to the frame  202 , (8) rotary position of the tooling head  204  relative to the frame  202 , (9) wire position (e.g., the position of the wire feed wheel  218  relative to the tooling head  204 ), and (10) other parameters as needed. At  308 , one or more of the measured parameters can be displayed. In one embodiment, the one or more parameters can be monitored continuously. In another embodiment, the frequency that the one or more parameters are monitored can be based on statistical data, or previous measurements from the monitoring of the one or more parameters. At  310 , the one or more sensed to parameters is recorded. 
     At  312 , it is queried as to whether the fabrication process is complete. If the fabrication process has not been completed, at  314 , it is queried as to whether the slot width  118  is of the appropriate size and/or whether the wire surface  124  of adjacent wires  110   a ,  110   b  are in alignment. If it is determined that the slot width  118  is not the appropriate size and/or the wire surface  124  of adjacent wires  110   a ,  110   b  are not in alignment, at  316 , one or more process control adjustments is made to the fabrication machine  200 . In one embodiment, the process control adjustments include at least one of the: (1) pitch  216 , (2) magnitude of the weld energy (e.g., electrical current supplied via the electrical current source  222 ), (3) weld pressure (e.g., tension in the wire  110  affected by the wire feed wheel  218  and/or the rotation of the tooling head  204  relative to the frame  202 ), (4) linear position of the tooling head  204  and/or wire feed wheel  218  relative to the frame  202 , (5) rate of advance (e.g., the rate of lateral shifting of the tooling head  204  and/or wire feed wheel  218  relative to the frame  202 ), (6) rotary position of the tooling head  204  relative to the frame  202 , (7) rate of rotation (e.g., the rate of the rotation of the tooling head  204  relative to the frame  202 , (9) wire position (e.g., the position of the wire feed wheel  218  relative to the tooling head  202 ), and (10) other process control adjustments as needed. Following a process control adjustments, at  306 , one or more parameters concerning the quality of the screen filter  100 , or components thereof, is again sensed or monitored, and the process continues. 
     Alternatively, if at  314 , it is determined that the slot width  118  is the appropriate size and/or the wire surface  124  of adjacent wires  110   a ,  110   b  are in alignment, at  318 , no process control adjustments are made, and the process advances to  306  for the sensing of one or more parameters concerning the quality of the screen filter  100 . 
     If at  312 , it is determined that the fabrication process is completed, at  320 , fabrication of the screen filter  100  is shut down. At  322 , sensed parameters and/or other data collected during operation  306  can be optionally stored in a memory. At  324 , optionally, the sensed parameters and/or other data collected during operation  306  can be utilized to generate a report. 
     It should be understood that the individual steps used in the methods of the present teachings may be performed in any order and/or simultaneously, as long as the teaching remains operable. Furthermore, it should be understood that the apparatus and methods of the present teachings can include any number, or all, of the described embodiments, as long as the teaching remains operable. 
     Referring to  FIG. 8 , a schematic of the fabrication machine  200  performing process  300  is depicted in accordance with an embodiment of the disclosure. During the process  300 , the fabrication machine  200  utilizes the feedback loop defined by process  300  to sense one or more parameters concerning the quality of the screen filter  100 , to affect a control of at least one of rotation of the tooling head  204 , the magnitude of electrical current via the electrical current source  222 , the tension of wire  110  via the wire feed wheel  218 , and/or the lateral position of the tooling head  204  and/or the wire feed wheel  218  and wire feed guide  220 , so as to achieve the desired penetration depth  123  of the wire  110  relative to the supporting rods  102  and/or the desired slot width  118  between adjacent wires  110   a ,  110   b.    
     Accordingly, in one example embodiment, the wire width  114  of wire  110  could be measured by the fabrication machine  200  as it is dispensed from the wire feed wheel  218 . If the wire width  114  is determined to be smaller than the mean wire width  114 , one or more process control adjustments can be made. For example, the linear position of the tooling head  204  and/or wire feed wheel  218  relative to the frame  202  can be adjusted to compensate for the smaller wire width  114  to achieve the appropriate slot width  118 , and the magnitude of the weld energy (e.g., electrical current supplied via the electrical current source  222 ) can be adjusted to achieve the appropriate penetration depth  123 . Other process control adjustments can be made as desired/needed to affect the desired characteristics of the screen filter  100  during fabrication. 
     In one embodiment, if the sensed wire width  114  is within a first predefined range, a first set of process control adjustments can be made. If the sensed wire width  114  is outside of the first predefined range, but within a second predefined range, a second set of process control adjustments, which can include the first set of process control adjustments plus additional process control adjustments, can be made. If the sensed wire width  114  is outside of the second predefined range, an operator of the fabrication machine  200  can be alerted via the display measurements, and the process  300  can be halted until appropriate corrections can be made. 
     Referring to  FIG. 9 , a bell curve illustrating a normal distribution of the monitored slot width  118  along a length of the cylindrical body  101  of a screen filter  100  is depicted in accordance with an embodiment of the disclosure. As illustrated, 68% of the slot width  118 , as measured circumferentially around the cylindrical body  101 , is within one standard deviation of the mean slot width  118 , 95.5% of the measured slot width  118  is within two standard deviations of the mean slot width  118 , and 99.7% of the measured slot width  118  is within three standard deviations of the mean slot width  118 . Accordingly, in some embodiments, the consistency in the measured slot width  118  is such that the screen filter  100  can reliably be used to remove the desired particulate matter. 
     In one embodiment, data collected during operation  322  can be analyzed by the fabrication machine  200 , and through a process of continually modifying different process control adjustments, for example by a Design of Experiments (DOE) process, the fabrication machine  200  can optimize characteristics of the fabricated screen filter  100 . 
     Various embodiments of systems, devices, and methods have been described herein. These embodiments are given only by way of example and are not intended to limit the scope of the claimed inventions. It should be appreciated, moreover, that the various features of the embodiments that have been described may be combined in various ways to produce numerous additional embodiments. Moreover, while various materials, dimensions, shapes, configurations and locations, etc. have been described for use with disclosed embodiments, others besides those disclosed may be utilized without exceeding the scope of the claimed inventions. 
     Persons of ordinary skill in the relevant arts will recognize that the subject matter hereof may comprise fewer features than illustrated in any individual embodiment described above. The embodiments described herein are not meant to be an exhaustive presentation of the ways in which the various features of the subject matter hereof may be combined. Accordingly, the embodiments are not mutually exclusive combinations of features; rather, the various embodiments can comprise a combination of different individual features selected from different individual embodiments, as understood by persons of ordinary skill in the art. Moreover, elements described with respect to one embodiment can be implemented in other embodiments even when not described in such embodiments unless otherwise noted. 
     Although a dependent claim may refer in the claims to a specific combination with one or more other claims, other embodiments can also include a combination of the dependent claim with the subject matter of each other dependent claim or a combination of one or more features with other dependent or independent claims. Such combinations are proposed herein unless it is stated that a specific combination is not intended. 
     Any incorporation by reference of documents above is limited such that no subject matter is incorporated that is contrary to the explicit disclosure herein. Any incorporation by reference of documents above is further limited such that no claims included in the documents are incorporated by reference herein. Any incorporation by reference of documents above is yet further limited such that any definitions provided in the documents are not incorporated by reference herein unless expressly included herein.