Valmet Paper Machinery Inc.

Valmet-karlstad Ab

Kmw Aktiebolag

Harry Ingemar Myren

Tord Gustav Gustavsson

Lars-Erik Roland Onnerlov

Anders Tommy Linden

Karl T Silja

A paper machine for manufacturing a web of soft crepe paper comprises a wet end (1) having at least one forming wire (4) for forming and supporting a web (7), and a drying section (2) with a through drying machine (13), a drying cylinder (17) and a perforated belt (19) running around a through-blow cylinder of the through drying machine and a transfer roll (21) at the drying cylinder, the web running through the through drying machine being exposed to drying air after its transfer from the forming wire. The belt (19) and the web (7) move from the through drying machine (13) to the drying cylinder (17) in a run that is free from mechanical means which would compress the web, whereby in said run the surface of the web which is exposed to the drying air faces away from the belt and remains free from contact with such means up to the drying cylinder.

Paper machine for manufacturing a web of soft crepe paper

An apparatus for removing dust released, for instance, during the production of a soft crepe paper web which is creped off a Yankee cylinder and spread laterally. The apparatus comprises a dust suction box consisting of a housing with an inner suction chamber, said housing having a first inlet in the form of a suction gap, a main part and first and second parts which define said suction gap between them. According to the invention the main part is in the form of part of a cylinder to provide a corresponding curved inner side in the suction chamber, and the suction gap comprises an outer gradual throttling and an inner gradual enlargement, said throttling and enlargement merging at a transition where said throttling is maximal. The first inlet forming part preferably comprises a flat surface that defines its side of said enlargement whereas the second part forming the inlet comprises both a curved surface having a predetermined radius and such an arc length that it defines the whole of its side of the throttling and an initial part of the enlargement, and also an inner, flat surface extending at a tangent from the curved surface and forming an acute angle .alpha. with a tangent to the curved surface at said transition.

Dust removal apparatus

A creping doctor (2) for creping a soft paper web (3) off a yankee cylinder (1) is described which comprises a supporting beam (4) disposed close to the envelope surface of the yankee cylinder (1) and provided with an internal space, the internal space being divided into a first longitudinal suction chamber (24) and a second longitudinal suction chamber (25). The creping doctor also produces a subatmospheric pressure in the suction chambers (24, 25); a first suction connection (18, 19, 21) connecting the first suction chamber (24) of the supporting beam (4) to an external dust-generating space (7) located between the doctor blade (6) and the soft paper web (3) creped off; and a second suction connection (40, 42, 43) connecting the second suction chamber (25) of the supporting beam (4) with an internal dust-generating space (8) located between the doctor blade (6) and the envelope surface of the yankee cylinder (1). According to the invention the creping doctor is provided with blowing means (50, 51, 58) for intermittent cleaning of the suction connections (18, 19, 21; 40, 42, 43) and suction chambers (24, 25) from dust deposited therein during operation.

Creping doctor with two suction chambers in the support beam

In a tissue paper machine, the dust that is released when the web is creped off the Yankee dryer (3) constitutes a major work environment problem. To provide an improved extraction of the dust and thereby improve the work environment for the operating personnel involved, a dust extractor (25') having an internal space (39') and a web stabilizing, imperforate plane (37') is mounted immediately adjacent to an intended path of travel for the creped web (1) so that the web during its transportation will place itself in a fixed position close to the imperforate plane (37'), and, at least an essential part of an entrained boundary layer of dust containing air is eliminated through suction only, to the internal space (39'). The suction is carried out at the rear and/or front edge of the extractor (25), and suitably both on the overside and underside of the web (1). Dust that does not become entrained in the boundary layers will be sucked away by at least one dust suction box (55) having a sloping suction box cover (57), and mounted under the web (1) and spaced therefrom at doctor beam (11). Preferably, an air stream, which is of sufficient force to carry the dust and caused by the suction, is made rise towards the web (1) between the dust suction box (55) and a dust extractor (27) mounted downstream of the latter.

Method and apparatus for extracting dust that is released when creping

A method and apparatus for delivering a multilayer stock jet to a forming surface in a papermaking machine with a multilayer headbox having a slice chamber formed by side walls and top and bottom walls terminating in lip members defining a slice opening and at least one relatively rigid stock separating partition fixed at its upstream end and attached to the side walls at points downstream of and at a distance from said upstream end and dividing the slice chamber into separate slice channels through which separate papermaking stocks are fed by separate pumps and discharged through the slice opening to the forming surface, in which ultrasound distance measuring devices are used to detect any deviation of the partition from a straight line connecting the points of its attachment to the side walls of the slice chamber and at least one of the stock feeding pumps is controlled in response to any detected deviation to reduce the deviation to a negligible value.

Growing community of inventors

Karlstad, Sweden

Harry Ingemar Myren