Abstract:
A shower header type spray device has a motorized cleaning brush on a rotary shaft mounted therein for cleaning inlet apertures of its spray nozzles. The brush shaft is supported to impart axial movement when it is rotated, and has a sealing valve attached thereon such that when the brush is rotated by the motor in a cleaning operation the valve is opened to allow discharge of liquid with debris brushed off the nozzle inlets. The motor is activated for a cleaning operation from either a local controller or a centralized controller that controls multiple spray devices.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application is a divisional of co-pending U.S. application Ser. No. 10/735,365, filed on Dec. 12, 2003, and claims the priority on U.S. Provisional Application 60/433,663, filed Dec. 16, 2002. 
     
    
     FIELD OF THE INVENTION  
       [0002]     The present invention relates generally to liquid spraying systems, and more particularly to shower header-type spray devices which are particularly adapted for spraying cleaning or washing fluid onto processing rollers in pulp and paper mills.  
       BACKGROUND OF THE INVENTION  
       [0003]     Shower header-type spray devices commonly are used for periodically cleaning processing rollers in pulp and paper mills. Such spray devices include an elongated header having a plurality of laterally spaced, downwardly directed liquid spray nozzles which are adapted for directing a curtain of water or other cleaning fluid onto a processing roller during periodic or other required cleaning cycles. Since a single processing machine can include a multiplicity of such header-type shower spraying systems, significant cleaning fluid is used. To conserve cleaning fluid, it is common to collect the cleaning fluid during the course of a cleaning cycle, filter out the debris and contaminants from the fluid during a recycling process, and to reuse the cleaning fluid. Nevertheless, some solid particles and matter can pass through the filtering system which over time can plug or impede liquid flow through one or more of the nozzles of the header.  
         [0004]     It is known for shower headers to include an elongated cleaning brush which can be rotated to cause the brush bristles to move across and clean the inlet apertures of the spray nozzles in the header. Heretofore, each time one or more of the spray nozzles becomes clogged, or during the regular cleaning cycles, it is necessary for an operator to go to the individual header and manually turn the cleaning brush of the header. Due to the multiplicity of such headers, which can be ten or more per machine, such cleaning process can be time consuming and tedious, requiring significant shut down in operation of the machine. It also necessitates that the operator go to each shower header, which can create a safety hazard to the operator due to wet and slippery surroundings.  
       OBJECTS AND SUMMARY OF THE INVENTION  
       [0005]     It is an object of the present invention to provide a shower header type spray device in which the spray nozzles thereof are adapted for easier and more efficient cleaning. A related object is to provide such a show header-type spray device adapted to substantially minimize costly labor in connection with periodic or other required cleaning of the spray nozzles of the spray device.  
         [0006]     Another object is to provide a shower header spray device as characterized above which can be more safely operated. In this regard, a related object is to provide such a shower header spray device that eliminates the necessity for an operator to go to or be in the vicinity of the spray device during nozzle cleaning operations.  
         [0007]     A further object is to provide a shower header spray device of the foregoing type which can be automatically operated during clean out operations.  
         [0008]     Still another object is to provide a spraying system that comprises a plurality of shower header spray devices of the foregoing type, the cleaning cycles of which can be controlled from a central control station.  
         [0009]     Yet a further object is to provide a shower header brush drive which is adapted for easy retrofitting assembly on existing shower headers in the field.  
         [0010]     Other objects and advantages of the invention will become apparent upon reading the following detailed description and upon reference to the drawings, in which: 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]      FIG. 1  is a diagrammatic depiction of an illustrative spraying system comprising a plurality of shower header-type spray devices in accordance with the invention;  
         [0012]      FIG. 2  is a longitudinal, vertical section of one of the illustrated shower header spray devices with a liquid control valve thereof in a closed spraying condition;  
         [0013]      FIG. 3  is a longitudinal, vertical section, similar to  FIG. 2 , showing the liquid control valve in an open nozzle cleaning position;  
         [0014]      FIG. 4  is an enlarged vertical section taken in the plane of line  4 - 4  in  FIG. 2 ;  
         [0015]      FIG. 5  is an enlarged perspective of the cleaning brush drive for the illustrated shower header spray device;  
         [0016]      FIG. 6  is a side elevational view of the cleaning brush drive with a cover thereof removed;  
         [0017]      FIG. 7  is a front view of a local operation controller that controls the motor to carry out a cleaning operation; and  
         [0018]      FIG. 8  is a front view of the local operation controller with a front panel opened to reveal components inside the controller. 
     
    
       [0019]     While the invention is susceptible of various modifications and alternative constructions, a certain illustrative embodiment thereof has been shown in the drawings and will be described below in detail. It should be understood, however, that there is no intention to limit the invention to the specific form disclosed, but on the contrary, the intention is to cover all modifications, alternative constructions, and equivalents falling within the spirit and scope of the invention.  
       DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0020]     Referring now more particularly to the drawings, there is shown an illustrative washing system  10  which has particular utility in pulp and paper processing and like. The illustrative spraying system  10  which includes a plurality of shower header-type spray devices  11  in accordance with the invention, each of which is adapted for spraying a cleaning fluid onto a respective roller  21  ( FIG. 2 ) of a pulp or paper-processing machine. While the illustrated spraying system  10  is described in connection with the direction of cleaning fluid in pulp or processing machines, it will be understood that the spraying system, including the individual header-type spray devices thereof, can be used for other liquid or spraying uses.  
         [0021]     Each illustrated shower header-type spray device  11 , as depicted in  FIG. 2 , includes an elongated generally tubular-configured header  14  supported in cantilever relation from a support frame  15 . Each header  14  has an upstream end connected to a pressurized liquid supply  16 , a drain pipe  18  communicating with a downstream end of the header  14 , in this case extending in radial downward relation to the header  14 , and a plurality of spray nozzles  20  mounted at uniformly spaced intervals laterally along the header  14 . The spray nozzles  20  may be of a known type, such as fan spray nozzles commercially available from Spraying Systems Co., assignee of the present application. Such nozzles are effective for discharging a respective fan spray pattern in partially overlapping relation for uniform liquid distribution onto a processing roller  21  or the like disposed below the header  14 . The spray device  14  in this case includes a valve member  28 , which is positionable against a valve seat  29  at the downstream end of the header  14  for sealing the downstream end of the header during a liquid spraying operation. Hence, pressurized liquid introduced into the inlet end of the header  14  is directed through the header and discharges through the plurality of spray nozzles  20 .  
         [0022]     As indicated above, shower header spray devices of the foregoing type have particular utility in cleaning pulp and paper particles from the rollers of processing machines in pulp and paper mills. To conserve washing fluid, it is customary to collect and recycle the cleaning fluids used during roller cleaning operations. Nevertheless, some particulate matter can be recirculated with the cleaning fluid, which over time can clog one or more of the spray nozzles, or otherwise necessitate periodic cleaning of the spray nozzles of the header. Heretofore, it has been necessary to manually effect cleaning of the spray nozzles of each spray header individually. Because of the multiplicity of processing rollers in each machine, this can be a tedious and time-consuming procedure that can significantly interrupt operation and efficiency of the machine.  
         [0023]     In accordance with the invention, each shower header spray device has a remotely controlled nozzle cleaning apparatus that can be selectively or automatically operated for cleaning the spray nozzles of the headers, without necessity for an operator to manually effect the cleaning process or even be in the vicinity of the header. In the illustrated embodiment, each header  14  has a respective cleaning brush  30  housed within the header which includes a rotatable shaft  31  having a plurality of brush segments  32   a ,  32   b  each comprising radial cleaning bristles. The brush shaft  31  is supported at opposite ends in appropriate bearings  34  for rotational and axial movement with respect to the header  14 .  
         [0024]     The brush segments  32   a ,  32   b  preferably are oriented in diametrically opposed relation to the shaft  31  such that as an incident to rotation of the shaft  31 , the brush segments  32   a ,  32   b  successively clean respective numbers of the laterally spaced spray nozzles  20 . In the illustrative embodiment, the brush segment  32   a  is operable for cleaning three laterally spaced spray nozzles  20  adjacent an upstream end of the header  14 , while the brush segment  32   b  is operable for cleaning the three laterally spaced spray nozzles  20  adjacent a downstream end of the header  14 .  
         [0025]     For imparting simultaneous axial movement of the brush shaft  31  as an incident to rotation thereof, a downstream end of the brush shaft  31  has a threaded pinion  36  which is disposed within a nut  38  fixed within a downstream housing section  39  of the header  14 . Hence, as an incident to the rotation of the shaft  31  in one direction, the pinion  36  moves axially to the left in the nut  38 , causing the brush segments  32   a ,  32   b  to move with a combination rotary and axial movement in sweeping fashion across the inlet ends of the nozzles  20  such that the bristles move any debris or solid material that is encumbering or clogging the passage of cleaning fluid to the nozzles. The valve member  28  in this case is mounted on a downstream end of the shaft  31 , such that such rotation of the shaft, which advances the brush  30  in a downstream direction, simultaneously moves the valve member  28  to an open position away from the valve seat  29 , allowing pressurized liquid from the supply liquid to carry removed debris through the header  14  and out the discharge drain  18 . Rotational movement of the shaft in an opposite direction causes the brush segments  32   a ,  32   b  to rotate and axially move in an opposite sweeping fashion across the nozzles  20  until the valve member  28  is seated with the valve seat  29 , closing the header  14  from the drain  18 , thereby enabling the header to resume a spraying.  
         [0026]     In carrying out the invention, for permitting remote and/or automatic rotation of the cleaning brush  30  during cleaning operations, a drive motor  40  is mounted on the support frame  15  and is operatively connected to the cleaning brush shaft for effecting rotation of the cleaning brush. The support frame  15  in this case comprises a pair of laterally spaced plates  41 ,  42  connected by connecting columns and bolts  44 . The header  14  is mounted in outwardly extending relation to one plate  41  while the drive motor  40  is bolted to the opposite from plate  42 . The motor  40  in this case has an output shaft which carries a drive pinion  48 , which is engageable with a relatively larger diameter drive gear  49  mounted on an upstream end of the brush shaft  31  for enhanced drive torque. The pinion and drive gears  48 ,  49  are sufficiently wide in the axial direction so as to permit limited longitudinal movement of the gear  49  relative to the pinion with the brush shaft  31  as an incident to the brush shaft being rotatably driven.  
         [0027]     In further keeping with the invention, the control of the movements of the drive motor  40  during a cleaning operation and the control of the sequence of steps in the operation are computerized to provide process automation. In a preferred embodiment, the motor  40  is a “smart” motor in the sense that the control electronics  50  ( FIG. 1 ), which includes a microprocessor  51 , for controlling the movements of the motor is located inside the housing of the motor. Suitable motors of such design are available, for example, from Oden Control AB in Sweden. The microprocessor in the motor  40  is programmed for pre-defined rotational directions, open and close positions, acceleration speed, rational speed and torque, etc.  
         [0028]     To control the operation of the motor to carry out the cleaning operation, external control signals are transmitted to the motor. In a preferred embodiment, each motor  40  has a local operation controller  52  mounted adjacent to it. As shown in  FIG. 7 , the housing  54  of the local operation controller  52  has two buttons  56  and  58  that an operator uses for initiating a cleaning operation to clean the spray device connected to the motor  40 . The button  56  on the top is a push-pull type “power-on” button for powering the controller  52  and the motor  40 . Power is supplied to the controller  52 , which in turn connects the power to the motor  40 , when the operator pulls the button  56  out to an “on” position. The button  56  also serves as an emergency-stop button that the operator can push down to cut the power and terminate the operation. The lower button  58  is a “Start” button of an illuminated type. The automated cleaning operation is triggered when the operator presses the Start button  58  after the controller  52  and the motor  40  are powered up. The button  58  also serves as a “ready” indicator, as its light is turned on when the cleaning operation is completed and the spray device is ready for use.  
         [0029]     The local operation controller  52  interacts with the control circuit of the motor  40  to carry out the cleaning operation. As shown in  FIG. 8 , the controller  52  includes a power supply  60  and a programmable logic circuit (PLC)  62  that contains the control logic (i.e., computer-executable instructions) for the cleaning operation. The PLC  62  is connected to the motor  40  via a printed circuit (PC) connector board  64  and a cable  66 . The cable  66  includes conductors for carrying power to the motor, input and out signal lines, and communication lines according to the RS232 standard between the PLC  62  and the motor control circuit  50 .  
         [0030]     To start a cleaning operation, the operator presses the Start button  58  on the housing of the controller  52  to send a start signal to the PLC  62 . Alternatively, a start signal may be generated and sent to the PLC by another controller, such as a central operation controller as will be described in greater detail below. In response to the start signal, the control program in the PLC  62  sends a command to the motor  40  to move to the full-open position. Responding to this command, the control circuit in the motor  40  moves the motor to drive the brush shaft  31  for several revolutions repeatedly, such as three revolutions in one direction, which causes the brush segments to move over the inlet of the spray nozzles in sweeping fashion from the combined rotational and axial movement of the brush shaft, simultaneously moving the sealing member  28  away from the valve seat  29 . As soon as the seal at the valve seat is opened, liquid pressure drops below the pressure required to direct liquid through the nozzles  20  so the liquid is diverted through the drain  18 , flushing any debris that is cleaned from the nozzles  20  out the drain  18 .  
         [0031]     After waiting for a programmed time-out period to allow the spray device to be adequately flushed, the PLC  62  sends another control command to the motor  40  to move back to the closed position. In response, the motor  40  reverses its rotational direction, causing the brush shaft  31  to rotate in an opposite direction for a similar number of revolutions, sweeping the nozzles  20  in the opposite direction, until the valve member  28  is reseated on the seat  29 . After another time-out period, the PLC  62  generates a “ready” signal by turning on an output line connected to the light of the Start button  58  to illuminate the button to indicate that the cleaning process is completed.  
         [0032]     To enable a greater level of automation and operational flexibility, in an alternative embodiment the local operation controllers  52  of the drive motors  40  are connected to a central operation controller  70 , as illustrated in  FIG. 1 . The central operation controller  70  controls the power on/off states of the local controllers  52  and generates start signals to the respective local controllers to start the cleaning operations of the corresponding spray devices  11 . When the cleaning operation of a spray device  11  is completed, the local controller  52  of that device transmits a ready signal to the central controller  70 . Using a central controller allows the cleaning operations to be controlled remotely. It removes the need for the operator to be physically on the floor of the spray devices, thereby providing greater operational safety and convenience. It also provides greater control flexibility, as the central controller  70  can be programmed to carry out cleaning operations of the individual spraying devices according to a desired schedule.  
         [0033]     It will be understood by one skilled in the art that the cleaning brush drive of the present invention may be adapted for convenient retrofitting of shower header-type spray devices in the field. The large reduction gear  49  can be mounted on the downstream end of the brush shaft  31 , and the drive motor  40  mounted on the header frame or valve housing, without significant rework. It will be seen that the drive motor is sufficiently small that it can be mounted on the header without interfering in the walkway along the machine. Again, the drive motors may be operated from respective individual controls, or from a central controller.