Alignment device and method for aligning a shower bar nozzle flange

#The invention relates to the field of shower bar nozzle flanges used for instance in a drum washer for washing pulp. More particularly, the invention relates to an alignment device and a method for aligning such a shower bar nozzle flange relative a permeable outer surface of a drum roll.

#During production of pulp, the pulp is usually washed at least once to remove chemicals from preceding process steps from the pulp. Such washing may be performed using a drum washer where a pulp mat formed on a permeable outer surface of the drum is washed by spraying or otherwise distributing wash liquid thereon.

#A type of device for spraying wash liquid is known as shower bars or pipes being elongated and extending along the outer surface of the drum. Such shower bars are provided with nozzles through which wash liquid flows out from the interior of the shower bar towards the drum.

#Above discussed and other aspects of the present invention will now be described in more detail using the appended drawings, which show presently preferred embodiments of the invention, wherein:

#FIG. 1 shows a cross section view of a shower bar provided with a nozzle flange having its flange end tangentially aligned with an outer surface of a drum washer roll;

#FIG. 2 shows a cross section view of a first embodiment of an alignment device according to the first aspect of the invention when used to align a nozzle flange end tangentially relative an outer surface as shown in FIG. 1;

#FIG. 1 shows a cross section view of an elongated hollow shower bar 6 having nozzle outlets (where only one nozzle outlet 5 is visible in the shown cross-section. A shower bar nozzle flange 2 is attached to the nozzle outlet 5, which nozzle flange is partly parabolically curved in the sense that it comprises a curved portion extending from the nozzle outlet 5 in the shower bar to a plane portion at the nozzle flange end 7 being about 0.5 inches long. The nozzle flange is to be aligned tangentially with the outer cylindrical surface 3 of the drum 4 so that the water flow runs as a uniform stream flooding the pulp mat. The flange is tangentially aligned in the sense that the plane portion at the flange end 7 is tangentially aligned with the outer cylindrical surface 3 as indicated by the dotted line in FIG. 1. The outer cylindrical surface 3 is permeable (normally formed as a face wire mesh) such that liquid can penetrate through a pulp mat disposed on the permeable surface 3 and be drawn in through the permeable surface by means of vacuum in the interior of the drum 4. In order to achieve optimum performance, the manufacturer of the nozzle flange typically specifies a predetermined optimum distance between the nozzle flange end and the outer cylindrical surface. This predetermined distance is typically 12-14 inches and is indicated by L in FIG. 1.

#FIG. 2 shows a cross section view of a first embodiment of an alignment device according to the first aspect of the invention when used to align a nozzle flange end tangentially relative an outer surface as shown in FIG. 1. FIG. 2 also illustrate a first embodiment of a system according to the second aspect of the invention. The alignment device 1 comprises a body element 8, an attachment device 9 and a contact element 11. The body element 8 has a length adapted to the above mentioned desired predetermined distance L between the nozzle flange end 7 and the outer cylindrical surface 3. The attachment device 9 is arranged at a first end 10 of the body element for releasably connecting the body element to the nozzle flange end to extend tangentially therefrom. The contact element is arranged at a second opposite end 12 of the body element forming a portion thereof. The contact element 11 abuts against the outer cylindrical surface 3.

#The attachment device 9 comprises a clamping device 13 having a clamping bar 14 arranged to act clampingly against the above-mentioned plane portion of the nozzle flange (at its end 7) by means of a spring 15. The clamping bar 14 is pivotably connected to the body element 8 around a pivot axis 14′. The body element comprises a substantially plane body portion 18 which forms a tangential extension of the nozzle flange end in the sense that it is parallel with the plane portion at the nozzle flange end 7. The body portion 18 extends in the lengthwise direction beneath the clamping bar 14 past the pivot axis 14′ such that the plane portion of the nozzle flange (at its end 7) is clamped between the body portion 18 and the clamping bar 14. The attachment device is furthermore provided with a straight guiding rib 18′ being attached to the body portion 18 and extending in a transverse direction of the alignment device. The nozzle flange end 7 is positioned in abutment with the guiding rib 18′ acting as a stop to make sure that the body portion 18 is in abutment with the plane portion of the nozzle flange to align tangentially therewith.