US 3103030 A
Description (OCR text may contain errors)
Sept. 10, 1963 R. cs. SANDS 3,103,030
EXTRACTING APPARATUS Filed June 24. 1960 2 SheetsSheet 1 F/GB.
' Inventor ROBERT G, SANDS A ttorneys Sept. 10, 1963 R. G. SANDS EXTRACTING APPARATUS Filed June 24. 1960 2 Sheets-Sheet 2 ONKO llmlll 11ml Inventor ROBERT G. SANDS BYMMM A tlorneys United States Patent 3,103,030 EXTRACTING APPARATUS Robert George Sands, Orpington, England, assignor to Carrier-Ross Engineering Company Limited, London,
England, a company of Great Britain Filed June 24, 1960, Ser. No. 38,518
Claims priority, application Great Britain June 25, 1959 1 Claim. (Cl. 15--306) This invention relates to extracting apparatus and in particular to apparatus for concentrating a sucking force on a zone of a drier roll intended for drying a continuous Web of material by direct contact with the roll.
It is a main object of the present invention to provide extracting apparatus in which a constant depression is maintained at the entrance of nozzles disposed side by side.
Accordingly, the present invention comprises a series of interchangeable nozzles of varying cross-section mounted on a suction (duct in communication therewith whereby on selecting nozzles of suitable cross-section a uniform sucking force is applied at the mouths of the nozzles.
Preferably the suction duct comprises a linear series of throats to each of which is attached a ferrule of tapering cross-section which is secured in position in the throat by being clamped between the throat and the nozzle and which progressively spreads in an outward direction from the ferrule and terminates in a narrow slot.
In order that the invention may be more clearly understood, an embodiment thereof will now'be described by way of example, with reference to the accompanying diagrammatic drawings, in which:
FIGURE 1 shows a section through a suction duct with nozzles according to the invention mounted relative to a doctor blade arranged to scrape a roll surface,
FIGURE 2 shows in elevation and to an enlarged scale a preferred manner of connecting a nozzle to the suction duct,
FIGURE 3 is a sectional elevation of line IIIIII of FIGURE 2, and
FIGURE 4 is a view in the direction of arrow A in FIGURE 1, indicating the graduated taper of ferrules for the nozzles.
In the drawings, like reference numerals designate the same or similar parts.
Referring to the drawings, FIGURE 1 illustrates the crest portion of a roll -1 over which a suction duct 2, the axis of which is parallel to the axis of the roll. The suction duct 2 is provided with a linear series of throats, 3, FIGURE 4 to each of which is attached, as hereinafter described, a nozzle 4, the duct 2 being connected to an exhausting system by a connecting duct 21, and the mouths of the nozzles 4 being [disposed side-by-side in relation to the surface of the roll 1 along the roll, such that the exhaust system produces at the nozzles the desired suction force over a zone running lengthwise of the roll, that is, parallel to the generatrices of the roll, and extending for the length of the roll. The suction duct 2 may be closed at one end and connected at the other end to a main duct of an exhausting system by the connection duct 21, but each end of the duct 2 may be provided with a flexible connection to the main duct.
The duct 2 where it is connected to a main duct of an exhausting system is supported at one end by the connection duct 21 being carried in a bearing block 22, and is carried or supported within a circular air tight housing such that the duct 2 is capable of rotation about its axis. At the other end the :duct is sealed by a blanlc disc 5 provided with a projecting spindle or trunnion 6 centrally disposed. This spindle is carried in a bearing (not shown) mounted on the machine frame, and to its extremity is attached a worm wheel 7 driven by a worm 8. The worm and worm wheel serve the dual purpose of retaining the nozzles 4 in close proximity to a doctor blade 9 and providing a means of manual adjustment of the duct 2 as required to compensate for the wear of the doctor blade 9 or to swing the nozzles 4' clear of the doctor blade 9 to enable this to be removed from contact with the cylinder 1 for access to the blade 9.
The doctor blade 9 is mounted in known manner on a doctor back or support 10* of circular section, which is mounted relative to the roll so that it can be rotated to lift the doctor blade 9 away from the roll 1. To this end the doctor back 10 is provided with a spindle (11 at each end carried in fixed bearings (not shown) attached to the machine frame, the assembly thus being rotatable about the centre lines of the spindles.
The nozzles 4 and the doctor blade 9 are operatively associated in such a way that as the roll rotates in the direction of the arrow 12, the suction force applied to the roll assures that the latter is continually cleaned by collecting the debris as it is detached by the doctor blade 9 from the roll.
As illustrated in FIGURES 2 and 3, each throat 3 is threaded to a respective neck 13 formed on the duct 2 and is flanged on its lower part as indicated at 14 to support a clamping ring '15 which is in threaded engagement with the head 16 of the nozzle walls 17. Clamped between the flange 14 of the throat 3 and the head 16 of the nozzle is flange 18 of a ferrule 19.
Accordingly, by rotating the ring 15 the nozzle is released and the ferrule can be removed and exchanged for another ferrule, whereon the nozzle will be replaced and the ring reversely rotated to clamp the substituted ferrule in position. r
The ferrule 19 has a tapering inner wall 20 and the taper of the inner wall determines the pneumatic depression in the respective throat and nozzle. By grading the internal taper '20 of the ferrules along the suction duct, as indicated diagrammatically in FIGURE 4, a constant air velocity along the length of the roll is achieved for the air entering the series of nozzles. Thus, the combined assembly of nozzles and suction duct can be adjusted to perform the required duty on the roll surface at the time of installation and the arrangement deters unauthorised interference with the setting of the nozzles. At the same time the manner of connecting the elements of the nozzle structure is such that a rigid construction is obtained, thereby preventing inadvertent slacking of the arrangement due to vibration or other cause.
From the foregoing it will be appreciated that a rigid nozzle structure is obtained in which the velocity of air entering the slots is uniform along the length of the zone to which suction is applied when the nozzle ferrules are appropriately graded to maintain a constant depression in the throats and the nozzle mouths.
By employing a means for immediately removing the debris from the vicinity in which it is detached from the roll, there is no opportunity for the debris to contaminate the web being dried on the roll or to become airborne and eventuallysettle on dilferent parts of the machine, which may result in faulty lubrication and indeed constitute a potential fire hazard.
Extracting apparatus for concentrating a uniform sucking force on a zone of a drier roll intended for drying a continuous web of material by direct contact with the roll, to collect debris detached from a zone of the roll, comprising a suction duct of uniform cross section for mounting lengthwise of the roll, means for applying"'suction to the duct, a linear series of equispaced throats of circular cross section in said duct, a series of identical suction nozzles respectively attached to said throats, each .nozzle progressively spreading from a circular cross section outlet and terminating in a narrow slot-shaped inlet which slot-shaped inlets are disposed si'cle-by-side parallel to a geneatrix of the roll, and a series of'interchangeable ferrules of conical internal cross section' each connecting one said nozzle to its associated throat in' that duct, an end of each ferrule terminating adjacent a nozzle outlet and having an internal circular cross section equal to that of the nozzle outlet, and the internal conical taper of the ferrules being progressively decreased along the duct from the connectionv of vthev duct to said suction means so that on the application of suction to the duct, air entering all the nozzle inlets has the same velocity and a constant depression is produced over said zone of the roll,
References Cited in the file of this patent UNITED STATES PATENTS 1,143,052 Kerr June 15, 1915 1,196,437 Doyle Aug. 29, 1916 1,196,438 Doyle et a1. Aug. 29-, 1916 1,298,471 Dodge Mar. 25, 1919 2,413,937 Zadernach et al'. Ian. 7, 1947 2,810,607 Hruby Oct. 22, 1957 I FOREIGN PATENTS 811,499 France Apr. 15, 1937