Patent Publication Number: US-7713359-B2

Title: Device for interior flushing of tanks or containers

Description:
FIELD OF THE INVENTION 
   The present invention relates to a device for interior flushing of spaces in tanks or containers, wherein at least one pipe is provided for the supply of flushing liquid to the space, wherein a rotatable part of the pipe has at least one flushing nozzle for discharging jets of flushing liquid and wherein a driving or operating device is provided to rotate said rotatable part of the pipe about a geometric rotation axis and the flushing nozzle about another geometric rotation axis. 
   BACKGROUND OF THE INVENTION 
   Devices for interior flushing of ship&#39;s tanks or similar are previously known from the publication EP 0 892 685. At the device according to this publication, one motor is used to rotate the rotatable part of a pipe for the supply of flushing liquid and another motor for rotating the flushing nozzle. Using two motors however, for rotating the rotatable part and the flushing nozzle, is an expensive and energy consuming solution which is sensitive to shutdowns. 
   SUMMARY OF THE INVENTION 
   The object of the present invention has therefore been to provide a substantial simplification and improvement of prior art. This is arrived at by providing the device defined above with the characterizing features of subsequent claim  1 . 
   By providing a reversible driving device through a double switch device operating either the flushing-liquid pipe or the flushing nozzle, a cheap, energy saving and reliable arrangement is obtained for operating the flushing device. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention will be further described below with reference to the accompanying drawings, in which: 
       FIG. 1  is a side view of a device according to the invention; 
       FIG. 2  is an enlarged view of a part of the device of  FIG. 1 ; 
       FIG. 3  is a plan view of a part of the device of  FIG. 1 ; 
       FIG. 4  is a section through a part of the device of  FIG. 1 ; 
       FIG. 5  illustrates a first alternative embodiment of a part of the device of  FIG. 1 ; and 
       FIG. 6  illustrates a second alternative embodiment of a part of the device of  FIG. 1 . 
   

   DESCRIPTION OF EXAMPLE EMBODIMENTS 
   The device  1  illustrated in the drawings is adapted for flushing spaces  2  in containers  3 , the upper side  4  of which has an opening  5 . The container  3  may be a ship&#39;s tank, whereby the upper side  4  may be the deck of the ship, but the container  3  can also be of another type and it can be transportable or stationary. 
   The flushing device  1  comprises at the embodiment according to the figures a supply conduit  6  for feeding flushing liquid  7  to a flushing-liquid pipe  8  and at least one flushing nozzle  9  mounted thereon and provided to discharge jets  10  of flushing liquid for interior flushing of the space  2 . 
   The supply conduit  6  has a vertically directed member  11  and a horizontally directed member  12  connected thereto. The flushing liquid  7  is brought to flow through the horizontally directed member  12  by means of a pump device (not shown) or similar to the vertically directed member  11  and through that member into the flushing-liquid pipe  8 . The horizontal member  12  may include a control valve  13  for regulating the inflow of flushing liquid  7  to the flushing-liquid pipe  8 . Lower parts of the vertically directed member  11  of the supply conduit  6  has a flange  14  which is attached to a larger flange  15  by means of bolts  16 . The larger flange  15  is in turn attached to said upper side  4  by means of bolts  17 . 
   At the top, the flushing-liquid pipe  8  is rotatably mounted in the vertically directed member  11  of the supply conduit  6  and extends through the opening  5  down into the space  2 . The flange  15  may have a downwardly directed bearing cage  18  with a bearing  19  which is located in the space  2  and in which the flushing-liquid pipe  8  is rotatably mounted. 
   On an upper part of the vertically directed member  11  of the supply conduit  6  there is provided a housing  21  for a driving or operating device  22  and a switch device  23 . The driving device  22  is provided to rotate, through the switch device  23 , the flushing-liquid pipe  8  about a geometric rotation axis R 1 A which in the present embodiment is vertically or substantially vertically directed, and to impart to the flushing nozzle  9  a movement about another geometric rotation axis R 2 A which in the present embodiment is horizontal or substantially horizontal. 
   The driving device  22  is provided to rotate in opposite rotary directions R 1  or R 2  by switching the rotary direction thereof. The switch device  23  is provided to transmit, when the driving device  22  is driven or operated to rotate in the rotary direction R 1  (e.g. clockwise), the rotary movement of the driving device  22  to the flushing-liquid pipe  8  for rotation thereof, but not to the flushing nozzle  9 . The switch device  23  is further provided to transmit, when the rotary movement of the driving device  22  is reversed such that it is driven in the opposite rotary direction R 2  (e.g. counter clockwise), said opposite rotary movement of the driving device  22  to the flushing nozzle  9  for rotation thereof, but not to the flushing-liquid pipe  8 . 
   The driving device  22  is operated preferably not by the flow of flushing liquid in the supply conduit  6  but by other energy. Thus, the driving device  22  may be an electrically, pneumatically or hydraulically driven or operated motor, whereby an electrically operated motor is the most suitable. The driving device  22  may be a servo-motor and it may operate with a rotation speed of 500-1000 rpm and bring the flushing-liquid pipe  8  to rotate, through the switch device  23 , with 0.5-1 rpm. 
   The switch device  23  has, in the embodiment shown, two driving gears  24 ,  25  and each gear includes a pair of transmission elements  26 ,  27 . A movement transfer means  28  is provided to transmit the rotary movements of the driving device  22  to the transmission element pairs  26 ,  27  of the two driving gears  24 ,  25  through two movement transfer and clearance devices  29 ,  30 . A transmission element pair  26 ,  27  in each driving gear  24 ,  25  is associated with each movement transfer and clearance device  29 ,  30  and one of said devices  29  is provided to transmit the movement of the movement transfer means  28  to the transmission element pair  26  of one of the driving gears  24 , while the other movement transfer and clearance device  30  is provided to simultaneously permit clearance such that the movement of the movement transfer means  28  is not at the same time transmitted to the transmission element pair  27  of the other driving gear  25 . The other movement transfer and clearance device  30  is provided to transmit the movement of the movement transfer means  28  to the transmission element pair  27  of said other driving gear  25 , while said one or first movement transfer and clearance device  29  is provided to simultaneously permit clearance such that the movement of the movement transfer means  28  is not at the same time transmitted to the transmission element pair  26  of said one driving gear  24 . 
   Each driving gear  24  and  25  respectively, is preferably a worm gear having a transmission element preferably in the form of a worm  31  and  32  respectively, which both are driven by the driving device  22  through the movement transfer means  28 , and a transmission element, preferably in the form of a gear wheel  33  and  34  respectively, cooperating with each worm  31  and  32  respectively. Each worm  31  and  32  respectively, is non-rotatably mounted on a drive shaft  35  and  36  respectively, which each includes a movement transfer and clearance device  29  and  30  respectively, such that the movement transfer means  28  cooperates with each worm gear through a movement transfer and clearance device  29  and  30  respectively. The gear wheel  33  of the driving gear  24 , i.e. of the pair of transmission elements  26 , brings the flushing-liquid pipe  8  to rotate by being connected thereto through a connecting member  37 , preferably in the form of a pipe, which extends through the vertically directed member  11  of the supply conduit  6  and which down below is attached to upper parts of the flushing-liquid pipe  8  for rotation of said pipe  8  about a geometric centre line CL relative to which the gear wheel  33 , the connecting member  37  and the flushing-liquid pipe  8  preferably are centered. 
   The driving gears  24 ,  25  in the form of worm gears may be of an irreversible type, meaning that they can rotate in one direction only. 
   The gear wheel  34  of the driving gear  25 , i.e. of the transmission element pair  27 , cooperates with a device  38  for transferring the rotary movements of the gear wheel  34  into reciprocating motions. This device  38  drives or operates in turn an elongated member  39 , preferably in the form of a rod, which is brought to move with reciprocating motions and which through a turning device (not shown) imparts oscillating movements to the flushing nozzle  9 . 
   The device  38  for transferring the rotary movements of the gear wheel  34  into reciprocating motions, may be constructed in different ways. At the embodiment of  FIG. 1 , this device  38  includes a carrier  40  which is centered with the centre line CL and which is driven by the gear wheel  34  to rotate about said centre line and about a threaded rod  41  or similar. Said rod  41  is also centered with the centre line CL and it is journalled to move in reciprocating motions relative to said centre line CL but not to rotate thereabout. The rod  41  has two threads  42 ,  43  with different thread directions and these threads  42 ,  43  transform into each other at thread transitions at the end portions of the threads  42 ,  43  and transform into each other such that the carrier  40  during continuous rotation in one direction can engage or mesh with one of the threads  42  and  43  and through said thread transitions pass over into engagement with the other thread  43  or  42  for imparting reciprocating motions continuously to the threaded rod  41  and thereby, movements to the flushing nozzle  9 . 
   The threaded rod  41  may cooperate with the flushing nozzle  9  through a coupling rod  44  or similar which extends in a direction downwards through the tubular connecting member  37  and the flushing nozzle  8  and which preferably is centered with the centre line CL. 
   The movement transfer means  28  can be an endless means, e.g. an endless belt or chain. This endless means runs over a rotating disk  45  on an output shaft of the driving device  22  and over two disks  46 ,  47  which through the movement transfer and clearance devices  29 ,  30  are located on the driving shafts  35 ,  36  of the worms  31 ,  32 . A gear wheel is an alternative to an endless means. 
   A control device  48  cooperates with the driving device  22  through a line  49  and is adapted to control the driving device  22  to rotate in either of the rotary directions, i.e. in one or the opposite rotary direction R 1  or R 2 . This means that the control device  48  controls the driving device  22  to rotate either the flushing-liquid pipe  8  or the flushing nozzle  9 . The control device  48  can be brought to control the driving device  22  in accordance with certain control programs which are chosen in view of the look of the space  2 . Such a control program can e.g. control the driving device  22  to rotate the flushing-liquid pipe  8  in one or several revolutions with the flushing nozzle  9  set for flushing a certain level of the space  2 . When this flushing is finished, the control program can control the driving device  22  to instead rotate the flushing-liquid pipe  8  to set it for flushing an adjacent level of the space  2 , and then, the control program controls the driving device  22  to once again rotate the flushing-liquid pipe  8  for flushing said latter level and so on. 
     FIG. 5  schematically illustrates a first alternative to the device described above for transferring a rotary movement into a reciprocating motion. At this first alternative, a pulley  51  (here replacing the gear wheel  34 ), a belt  52  and a connecting rod  53  is used. The belt  52  is provided to transmit the rotary movement of the worm  32  to the pulley  51  such that said pulley rotates in the rotary direction R 3 . The connecting rod  53  cooperates, with an upper end, with the pulley  51  and, with a lower end, with the coupling rod  44 , such that when the pulley  51  rotates in the rotary direction R 3 , up- and downward motions are imparted to the connecting rod  53 , which are transmitted to the coupling rod  44 . Thus, a rotary movement is here transferred into a reciprocating motion R 4  through a connecting rod movement. 
     FIG. 6  schematically illustrates a second alternative to the device described above for transferring a rotary movement into a reciprocating motion. At this second alternative, a cam disk  54 , an arm  55  and a roller  56  which is rotatably mounted on said arm, is used. The cam disk  54  is brought to rotate along with the tubular connecting member  37 . The cam of the cam disk  54  is inclined relative to the longitudinal direction of the coupling rod  44 , one end of the arm  55  cooperates with the machine and its other end with the coupling rod  44 . Since the roller  56  runs on the inclined cam of the cam disk  54 , it will impart to the arm  55 , and thereby to the coupling rod  44 , up- and downwardly reciprocating motions R 5 . Thus, a rotary movement is here through a cam movement transferred into a reciprocating motion R 5 . 
   The invention is not limited to the embodiment described above and illustrated in the drawings, but may with regard to its construction and function vary within the scope of the subsequent claims. Thus, the driving or operating device  22 , the switch device  23  and the transfer device  38  may e.g. be constructed otherwise than described. The control valve  13  may cooperate with a control device  50  which preferably is remote-controlled and which can control the control valve  13  to let pass larger or smaller amounts or volumes of flushing liquid per time unit. The control device  50  may e.g. temporarily interrupt the flow of flushing liquid through the supply conduit  6  if e.g. the flushing nozzle  9  has flushed a part of the space  2  and one wishes to redirect the nozzle towards another part of the space  2  without flushing during this redirection.