EP0413671A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Suction roll
Assignee: Valmet Technologies Oy
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Filing: 1990-08-16
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Granted: —
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Expires: 2010-08-16
Abstract
Abstract The invention relates to a suction roll (10) comprising a turbulence suppression apparatus (16) located at least in the vicinity of the end of a suction pipe (15) of the suction roll. The turbulence suppression apparatus comprises at least one plate element, whose surface (E) is essentially in the direction of the radius (R) of the roll (10′). The turbulence suppression apparatus (16) is fitted relative to the end of the suction-pipe (15) in such a way that the turbulence of air sucked in the suction phase is prevented and that the underpressure is thus maintained in the desired, approximately constant value on the inner surface of the roll shell along the entire roll width and the quantity of suction air in the desired, approximately constant value through the perforation (14) of the roll shell.
Inventors
- 👤 Antti Kuhasalo
- 👤 Olavi Viitanen
- 👤 Heikki Ilvespää
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-29 16:34
CPC Classifications
D; D21; D21F; D21F3/00; D21F3/02; D21F3/10
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
261 words
A suction roll (19) comprising a roll shell (11) rotated on journals (12a and 12b) and which roll shell (11) comprises a perforation (14), wherein several holes (14a) are led through the roll shell (11), whereby the suction is directed to the internal space (C) of the roll shell (11) and air is sucked through the perforation (14) to press the paper web toward the outer surface of the roll shell, and which suction roll (10) comprises an internal space (C) of the roll shell (11), to which underpressure is directed directly from a suction pipe (15), the interior (C) of the suction roll (10) having essentially no suction box or a corresponding device arrangement, by means of which the suction is directed only to the holding-down sector, characterized in that the suction roll (10) comprises a turbulence suppression apparatus (16) located at least in the vicinity of the end of the suction pipe (15) of the suction roll, the apparatus comprising at least one plate element, whose surface (E) is essentially in the direction of the radius (R) of the roll (10′), and which turbulence suppression apparatus (16) is fitted relative to the end of the suction-pipe (15) in such a way that the turbulence of air sucked in the suction phase is prevented and that the under-pressure is thus maintained in the desired, approximately constant value on the inner surface of the roll shell along the entire roll width and the quantity of suction air in the desired, approximately constant value through the perforation (14) of the roll shell.
Claim 2
Dependent Claim
261 words
A suction roll (19) comprising a roll shell (11) rotated on journals (12a and 12b) and which roll shell (11) comprises a perforation (14), wherein several holes (14a) are led through the roll shell (11), whereby the suction is directed to the internal space (C) of the roll shell (11) and air is sucked through the perforation (14) to press the paper web toward the outer surface of the roll shell, and which suction roll (10) comprises an internal space (C) of the roll shell (11), to which underpressure is directed directly from a suction pipe (15), the interior (C) of the suction roll (10) having essentially no suction box or a corresponding device arrangement, by means of which the suction is directed only to the holding-down sector, characterized in that the suction roll (10) comprises a turbulence suppression apparatus (16) located at least in the vicinity of the end of the suction pipe (15) of the suction roll, the apparatus comprising at least one plate element, whose surface (E) is essentially in the direction of the radius (R) of the roll (10′), and which turbulence suppression apparatus (16) is fitted relative to the end of the suction-pipe (15) in such a way that the turbulence of air sucked in the suction phase is prevented and that the under-pressure is thus maintained in the desired, approximately constant value on the inner surface of the roll shell along the entire roll width and the quantity of suction air in the desired, approximately constant value through the perforation (14) of the roll shell.
Claim 3
Dependent Claim
110 words
A suction roll according to claim 1, characterized in that the suction roll comprises at least one plate element (21), which is fitted to the end on the side of the suction pipe (15) of the suction roll and whose surface (E) is by its level essentially located in the direction of the radius (R) of the roll (10) and essentially so that the air sucked through the perforation (14) of the roll, when it begins to flow tangentially in the direction of the circumference of the roll shell, contacts essentially perpendicularly the surface (E) of the plate (21) of the turbulence suppression apparatus (16), whereby turbulence is effectively prevented.
Claim 4
Dependent Claim
63 words
A suction roll according to claim 1, characterized in that the turbulence suppression apparatus (16) is comprised of two plate elements (17a,17b), which are fitted approximately radially so that they are connected by a third plate element (17c), whose construction essentially corresponds to a U-profile, the air flow being led inside the profile through its ends and further to the suction pipe (15).
Claim 5
Dependent Claim
55 words
A suction roll according to claim 3, characterized in that the U-profile construction comprises a plate element (18), which is fitted essentially centrally on the rotational axis (X) and in such a way that the plate level of the plate element (18) is located essentially radially relative to the rotational axis (X) of the roll.
Claim 6
Dependent Claim
122 words
A suction roll according to claim 1, characterized in that the suction roll comprises at least one radial plate element (20), whose plate level is located in the direction of the radius (R) of the roll (10) and to which plate element (20) is connected a circular plate (19), whose plate level (T) is located in the direction of the level of the radius (R) of the suction roll, and which plate element (19) is fitted relative to the inner surface (11′) of the suction roll in such a way that a sufficient gap remains for supplying air from between the upper part of the plate element (19) and the inner surface (11′) of the roll shell to the suction pipe (15).
Claim 7
Dependent Claim
90 words
A suction roll according to claim 1, characterized in that the perforation (14) comprises a groove (14b) or a recess connected with a hole (14a) extending through the roll shell, whereby the ratio of the total cross-sectional flow area (A₀) of the holes to the total cross-sectional flow area of the perforated grooves or recesses is within the range of 1:10 - 1:150 and most preferably within the range of 1:50 - 1:110 and that the air flow through the perforation (14) is within the range of 500-1500 m³/m h.
References Cited (Backward Citations)
No citation records indexed.
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