METHOD AND APPARATUS FOR CLEANING CYLINDRICAL COMPONENTS WHICH ARE TRANSVERSELY ROTATED IN A DRUM DURING LIQUID TREATMENT

Abstract: In accordance with a method and in an apparatus (1) for cleaning long tubes (21) the cleaning process is effected during transverse advancement of the tubes by means of a drum-shaped, rotatable conveyor (12) from an inlet positioned at one lengthwise side wall (6) of the apparatus (1) to an outlet positioned on the opposite lengthwise side wall (7) via a cleaning zone (25) containing a flushing unit (27) arranged to flush a cleaning fluid (11) at a high pressure and in a large flow about and through the tubes (21).

Description: METHOD AND APPARATUS FOR CLEANING CYLINDRICAL COMPONENTS WHICH ARE TRANSVERSELY ROTATED IN A DRUM DURING LIQUID TREAΩENT The subject invention concerns a method and an apparatus for cleaning elongate objects, such as tubes, preferably metal tubes. Following manufacture and severing of tubes to the desired lengths, 2 - 6 meters, for instance, the tubes must be cleaned before use to remove dirt, such as oil an grease. Generally, the tubes are immerged into hot cleaning baths or apparatuses known as trichloroethylene apparatuses. These methods are inconvenient, time- consuming and do not produce the desired result, particularly as regards removal of chips, grindings and so called rolling dust. Trichloroethylene apparatuses cause other problems as well, especially to the environment, and are becoming obsolete. In other cases goods of elongate shape are cleaned lengthwise, in tunnel cleaners. From the point of view of washing efficiency such cleaners are satisfactory but the require considerable floor space and their capacity is comparatively low. This cleaning method does not either lend itself to internal cleaning of the tubes. Mechanical cutting of the elongate objects normally precedes the cleaning thereof. The rapid development of automatic cutting machines in later years has increased the demands for cleaning installations having higher capacities than those afforded by the methods outlined above. The purpose of the invention is to suggest a method and an apparatus allowing efficient, rapid and space- saving cleaning of elongate objects as described above. With respect to the method according to which the elongate objects are introduced into a cleaning apparatus are cleaned by a cleaning liquid contained in said apparatus and are subsequently removed from the apparatus this purpose is achieved by advancing the elongate object transversely inside the cleaning apparatus while flushing them internally and externally with the cleaning liquid. With respect to the cleaning apparatus having an inlet for introducing the dirty elongate objects there¬ into, a container holding the liquid for cleaning the elongate objects, and an outlet for removal of the elongate objects after cleaning thereof, the same purpose is achieved by means of a conveyor advancing the elongate objects transversely from the inlet situated on one of the lengthwise side walls of the apparatus to the outlet at the opposite lengthwise side wall thereof, and a cleaning zone including a flushing unit which flushes the cleaning liquid at a high pressure and in a large flow about and through the elongate objects during at least a part of their advancement from the apparatus inlet to the outlet. The invention will be described in closer detail in the following with reference to the accompanying drawing figures illustrating a presently preferred embodiment of the cleaning apparatus and wherein, Fig. 1 illustrates the apparatus schematically in a perspective view obliquely from above, certain parts having been cut away in order to illustrate components behind, Fig. 2 is a longitudinal sectional view through the apparatus in Fig. 1, Fig. 3 is a transverse sectional view through a part of the apparatus along line III-III of Fig. 2, and Fig. 4 likewise is a transverse sectional view through the apparatus, in this case along line IV-IV of Fig. 2. The cleaning apparatus illustrated in the drawings and designated generally by reference 1, is an elongate frame construction erected from frame profile members 2 and covering sheet-metal plates 3 not described herein in detail, and comprising a bottom 4, a top wall 5, front and rear side walls 6 and 7 and end walls 8. The interior of the apparatus 1 contains a preferabl heat-insulated container 9 holding a cleaning fluid 11 which reaches up to a level 10, said cleaning fluid containing water and a detergent, such as 2% of a neutral detergent comprising corrosion inhibiting agents. A conveyor, designated as a whole by numeral refer¬ ence 12, is placed inside the container 9 so as to be housed entirely above the cleaning fluid level 10 vertically. In accordance with the embodiment illustrated, the conveyor 12 is a drum 13 rotatably mounted inside the container 9, the drum ends 14, 15 being rotatably suppor¬ ted by support rollers 16. In a manner to be described in closer detail in the following, the drum is arranged to rotate continuously or intermittently about a centre shaf 17 having a slight inclination with respect to the horizontal plane. The shaft is driven by a drive motor 18, which via a gear 19 on the motor output shaft drives a drive wheel 20 which is fixedly secured to the drum 13. The purpose of the drum 13 is to move the elongate objects 21, such as tubes, preferably metal tubes to be washed, transversely from an inlet 22 disposed on the front side wall 6 of the apparatus 1 for introduction int the apparatus of the dirtly elongate objects 21, to an outlet 23 situated on the opposite rear side wall 7 of th apparatus for removal of the washed elongate objects. In order to thus advance the objects, the drum 13 is provided with pockets 23 arrranged, during the drum rotation, to receive in succession elongate objects 21 transversely from the inlet and thereafter to carry the objects past a cleaning zone 25 and further onto the outlet 23 for delivery of the cleaned objects so said outlet for further handling. The pockets 24 preferably ar equally distributed over the entire periphery 26 of the drum and preferably they extend over substantially the entire length of the drum, from one end 14 thereof, to th opposite end 15. As appears from the drawing figures, said cleaning zone 25 is positioned within the upper half of the drum 13 and comprises a flushing unit, generally designated by reference 27. The unit is arranged to emit a large flow of cleaning fluid 11 at a high pressure around and through the elongate objects 21, i.e. on the internal and the external faces thereof, over at least a part of the path of advancement of the objects from the inlet 22 to the outlet 23, more precisely in the part thereof correspond- ing to the cleaning zone 25. In accordance with the embodiment illustrated the flushing unit 27 is in the form of a distributor box 28 having an inlet which via a supply pipe 30 is connected to the pressure side of a pump 31, such as a vertically oriented centrifugal pump, the suction side of which is connected to the container 9 below the cleaning fluid level 10 via a suction pipe. In accordance with the embodiment illustrated, the distributor box 28 is formed with four outlets 33 in which flushing nozzles 34 are mounted. In the cleaning zone 25, the distributor box 28 is positioned in the area of the higher-level end 14 of the drum 13 and the flushing nozzles 23 are set to effect their flushing action in the lengthwise direction of the pockets 24 and thus in the lengthwise direction of the elongate objects 21, ensuring that the objects are well flushed on all sides, internally as well as externally, as mentioned previously. The pockets 24 on the periphery 26 of the drum 12 open outwardly and are delimited laterally by follower means 35 of preferably stainless steel which are mounted on the drum jacket face 26 so as to extend obliquely outwards, so that the follower means 35 present a configuration similar to that of vanes or lamellae. In the area of the cleaning zone 25 the pockets 24 are, however, covered by a covering member 36 which in accordance with the embodiment illustrated preferably is shaped as a screen 37 of a liquid-tight, pliable material, such as a durable cloth of rubber, or a weave of plastics or similar material, which extends across mainly the upper half of the drum 13. By means of conventional tightening means 38, not shown, the pliable screen 37 may be pre-stressed to a pre¬ determined tension in such a manner that the side thereof facing the drum yieldingly and tightly abuts against the free outer ends 39 of the follower means 35 as is most clearly apparent from Fig. 3. Owing to the covering member 36 described above, the pockets 24 in the cleaning zone 25 are closed outwards, except at the sides, allowing cleaning fluid 11, during the flushing of the elongate objects 21, to flow through the closed pockets from the flushing nozzles 34 at the higher-level end 14 of the drum to the outlet 40 posi¬ tioned at the lower-level end'15 thereof and further down into the container 9 via a collector board 41 inclining in the same direction as the drum 14, and a filter 42, for cleaning and re-circulation. In order to maximize the cleaning effect on the elongate objects 21 one or several of the flushing nozzles 34, positioned in the beginning of the cleaning zone as seen in the direction of rotation A of the drum, emit a larger flow of cleaning liquid than the subsequent flushing nozzles in order to fill the pockets 24 - which are closed in the cleaning zone - with flushing cleaning fluid 11 as rapidly as possible. To prevent the elongate objects 21 that are posi- tioned in the pockets 24 in the cleaning zone from being forced out through the outlets 40 at the lower-level end 15 of the drum 30 when affected by the powerful cleaning fluid flow, the outlets 40 preferably are covered by a grid 43. Thus, the cleaning fluid 11 leaves the pockets 24 via the grid-covered outlets 40 at a high pressure and in a considerably flow. In order to guide the cleaning fluid towards the collector plate 41 while at the same time avoiding unnecessary splashing in the area of the upper part of the drum 13, a curved splash guard 44 is provided in the area of the upper drum part and said outlet 40, said splash guard 44 being secured to the inner face of one of the end walls 8 of the cleaning apparatus 1 so as to extend a certain distance in over and around the drum 13. Downstreams of the cleaning zone 25 proper, i.e. to the right of the flushing unit 27 in accordance with Figs. 3 and 4, a rinsing device, not shown, may be provided if desired, in order to rinse the elongate objects after cleaning thereof in the cleaning zone 25, and/or a dryer mechanism, not shown either, may be provided to dry the elongate objects 21 internally or externally before they leave the cleaning apparatus 1 via the outlet 23 therein. The cleaning liquid 11 in the container 9 is heated ' to approximately 80° C by means of a heater, not shown, in the container 9, and in order to remove the condensation and the moisture generated during the cleaning a suction hood 45 is arranged on the top wall 5 of the apparatus 1, a hose, a tube or the like 46 connecting the suction hood 45 to an evacuation fan or the like, not shown. The invention is not limited to the embodiment desribed in the aforegoing and illustrated in the drawings but may be modified in a variety of ways within the claimed scope of protection.

Claims: C L A I M S. 1. A method of cleaning elongate objects, such as tubes, according to which method the elongate objects ar introduced into a cleaning apparatus, are cleaned with a cleaning fluid in said apparatus and after cleaning they are removed from the apparatus, c h a r a c t e r i z e in that the elongate objects are advanced transversely inside the cleaning apparatus while being flushed internally and externally by the cleaning fluid. 2. An apparatus for cleaning elongate objects (21) such as tubes, said apparatus (1) having an inlet (22) for introduction of the dirty elongate objects (21), a container (9) holding the liquid (11) for cleaning the elongate objects (21), and an outlet (23) for removal of the elongate objects, after cleaning thereof, c h a r ¬ a c t e r i z e d by a conveyor (12) arranged to advance the elongate objects (21) transversely from the inlet (23) positioned on one of the lengthwise side wall (6) of the apparatus (1) to the outlet (23) on the opposite side wall (7) thereof, and a cleaning zone (25) including a flushing unit (27) which flushes the cleanin liquid (11) at a high pressure and in a large flow about and through the elongate objects (21) during at least a part of the advancement thereof from the inlet (22) to t outlet (23). 3. An apparatus as claimed in claim 2, c h a r ¬ a c t e r i z e d in that the conveyor (12) is a drum (13) which is rotatably mounted inside the container (9) and which is formed with pockets (23) for reception in succession of the elongate objects (21) transversely during the rotation of the drum from the inlet (22) and subsequent displacement of the elongate objects past the cleaning zone (25) and from there to the outlet (23) so to deliver the washed objects to said outlet. 4. An apparatus as claimed in claim 3, c h a r ¬ a c t e r i z e d in that the drum (13) is arranged to rotate continuously or intermittently about a centre shaft (17) extending at a slight angle to the horizontal plane, in that the pockets (24) are distributed around the circumference (26) of the drum (13) and extend along essentially the entire length thereof, and in that the cleaning zone (25) is located within the upper half of the drum (13). 5. An apparatus as claimed in any one of claims 2-4, c h a r a c t e r i z e d in that the flushing unit (27) is formed with flushing nozzles (34) which are set so as to flush the elongate objects (21) lengthwise, internally as well as externally. 6. An apparatus as claimed in claim 5, c h a r ¬ a c t e r i z e d in that the flushing unit (27) is in the form of a distributor box (28) having an inlet (29) which is connected to the pressure side of a pump (31), the suction side of which is connected to the container (9) below the level (10) of the cleaning fluid therein, and in that the flushing nozzles (34) are mounted in outlets (33) in the distributing box (28). 7. An apparatus as claimed in claim 6, c h a r ¬ a c t e r i z e d in that the distributor box (28) is arranged in the area of the higher-level end (14) of the drum and in that the flushing nozzles (34) flush in the lengthwise direction of the pockets (24) and thus in that of the elongate objects (21). 8. An apparatus as claimed in any one of claims 5-7, c h a r a c t e r i z e d in that one or several of the flushing nozzles (34) positioned at the starting end of the cleaning zone (25) as seen in the direction of rotation (A) of the drum (13) emit a larger flow of cleaning fluid than do the subsequent nozzles in order to successively fill the pockets (24) with flushing cleaning fluid (11) as rapidly as possible. 9. An apparatus as claimed in any one of claims 3-8 c h a r a c t e r i z e d in that the pockets (24) are open outwards and are delimited laterally by follower members (35) arranged on the circumference (26) of the drum (13) and directed obliquely outwards, and in that in the area of the cleaning zone (25) the pockets (24) are covered outwardly by a covering means (36), closing the pockets (24) in the cleaning zone outwards and laterally and allowing the cleaning fluid (11), while flushing the elongate objects (21), to flow through the closed pockets from the flushing nozzles (34) at the higher-level end (14) of the drum (13) to outlets (40) positioned at the lower-level end (15) thereof and further down into the container (9) to be cleaned and re-circulated. 10. An apparatus as claimed in claim 9, c h a r ¬ a c t e r i z e d in that the covering means (36) is formed from a screen (37) of a-water-tight and pliable material which is arranged so as to extend across essentially the upper half of the drum (13), said screen (37) abutting yieldingly and tightly against the -outer free ends (39) of the follower members (35) under the influence of a predetermined pre-stress force.

Inventors: LITHANDER ERIK, LITHANDER, ERIK
Applicants: NIAGARA MACHINERY AB
Application year: 1993
Main classification: B08B3
IPC codes: B08B3, B08B9, B21C43, B65G49, C23G3