FRAME CONSTRUCTION OF THE PRESS SECTION IN A PAPER MACHINE

Abstract: The invention relates to the frame construction of the press sec­ tion of a paper machine. The press section comprises a roll com­ bination (1, 2, 3, 4, 5), the rolls of which form one or a plura­ lity of nips (N1, N2, N3), members for guiding the paper web through the press section and members for guiding one or a plura­ lity of felts (6, 7) into contact with the press section. The frame construction comprises a front frame (8), a rear frame (9) and an intermediate frame (10) connecting these two from above the press section. The connections (11, 12) of the intermediate frame (10) both to the front frame and to the rear frame are disposed to be releasable in order to remove the intermediate frame from above the roll combination, the removal being disposed to be performed essentially horizontally.

Description: The invention relates to the frame construction of the press sec­ tion in a paper machine, the press section comprising a roll com­ bination, the rolls of which form one or a plurality of nips, members for guiding the paper web through the press section and members for guiding one or a plurality of felts or the equivalent into contact with the press section, the frame construction com­ prising a front frame, a rear frame and an intermediate frame con­ necting these two from above the press section. Constructions of this type are used to some extent nowadays. Beloit Corporation has proposed the so-called "FLIP-TOP"-frame construction. In this construction, a two-piece intermediate frame is disposed above the press section of the paper machine to con­ nect the front and rear frames of the press section. During the operation of the press section, the ends of the intermediate fra­ me are fixed both to the front and the rear frame. Either of the­ se attachments can be detached and the detached portion of the intermediate frame can be pivoted into the centre of the interme­ diate frame, around the transverse articulated shaft of the paper machine. The partial opening of the intermediate frame has the purpose of facilitating the felt exchange on the press section. The "FLIP-TOP"-frame construction does not essentially improve other functions relating in particular to the service or operability of the press section. Valmet Oy has proposed several frame constructions of the press section. The so-called SYM-PRESS press section is known, in which horizontal beams providing a solid connection of the front and real frames of the press section are disposed above the press rolls in a compact press section, both on the service and the driving side of the paper machine. This kind or solution is dif­ ficult in particular with regard to the services of the press section, since, being stationary above the press section, the beams hamper and delay the service operations. The further deve­ lopment of this frame construction has resulted in the solutions described in the Finnish patent applications 844693 and 854959 of Valmet Oy. These publications disclose intermediate frame const­ ructions, in which a one-piece intermediate frame is pivotally articulated to the rear frame of the press section and disposed to be detachably fixed to the front frame (FI-844693), or alternati­ vely, the intermediate frame consists of two pieces, the pieces being articulated into the front frame on the one hand and into the rear frame on the other hand (FI-854959). The free ends of the pieces of the intermediate frame are disposed to be fixed to the fixed intermediate part of the intermediate frame (FI-854959). The intermediate frames described above are pivotable around their articulating points in the vertical plane partly away from above the roll arrangement of the press section especially in view of service operations. It is difficult to make this type of con­ structions sufficiently solid and thus vibrationless. The constructor of the press section of a modern paper machine has to fulfill two opposite requirements. On the one hand, the frame construction of the press section - the front frame, the rear frame and the intermediate frame connecting these two - should form a sufficiently rigid construction, which, during the operation of the press section, ensures a trouble-free operation of the press section. However, on the other hand, the compact press section, the machine elements of which - press rolls, press fabrics and members for guiding the web - are very close to each other in the operating position, should, in view of the necessary repeated services of the paper machine, have a construction that allows to perform the service operations in a reasonable time. This means that the press section should be capable of being ope­ ned to a necessary extent relatively easily and the above machine elements should be easily available in such an opened position. The object of the present invention is to provide a press section that fulfills the requirements described above. The press section carried out according to the invention is rigid in the operating position and on the other hand it allows the machine elements in the press section to be easily and rapidly serviced. In order to achieve this purpose, the press section according to the invention is essentially characterized in that the connec­ tions of the intermediate frame both to the front frame and to the rear frame are disposed to be releasable in order to remove the intermediate frame from above the press section and in that the removal is disposed to be carried out essentially horizontal­ ly. In this case, the front and rear frames of the press section are firmly connected to each other by the intermediate frame in the direction of the machine during operation. Thus, a rigid frame assembly is formed. During service operations, the intermediate frame is horizontally detachable and displacable in order to ac­ celerate the felt exchange, the roll exchange and other service operations. The invention is illustrated in the following description with reference to the enclosed drawing, which presents the press sec­ tion and its frame construction as a schematic lateral view. The frame construction of the press section represented in the drawing comprises the roll combination 1, 2, 3, 4 and 5. The rolls form the three nips N1, N2 and N3. The press section further comprises members for guiding the paper web through the press section and members for guiding one or a plurality of felts 6, 7 into contact with the press section. The frame construction com­ prises the front frame 8, the rear frame 9 and the intermediate frame 10 connecting these two from above the press section. Since the actual structural makeup of the press section does not enter into the scope of the invention, it will not be described in de­ tail here. It is merely noted that in the frame construction ac­ cording to the invention all prior known press section solutions are applicable with regard to the roll combination and the other machine elements. The intermedediate frame 10 comprises one or a plurality of beams 10 disposed in the longitudinal direction of the paper machine. The intermediate frame can be disposed on both sides of the paper machine. The beams can form one integral assembly or they can be disposed separately. At both ends of the intermediate frame 10 members 11a, 12a, are provided, which are disposed to cooperate to provide an interlocking with the countermembers 11b in the front frame 8 on the one hand, and with the countermembers 12b in the rear frame 9 on the other hand. This type of interlocking members can be constructed according to principles that are clear to a person skilled in the art, and consequently their detailed construction will not be described here. Owing to the joints 11 and 12 formed by the members 11a, 11b; 12a, 12b, a rigid assembly of the frame construction is achieved in the operating position. The intermediate frame 10 is removable from above the roll combi­ nation 1 to 5. The removal is disposed to be effected essentially horizontally. In the described embodiment this displacement is performed in the longitudinal direction of the paper machine. For this purposes support means 17 are disposed in the removal direc­ tion of the intermediate frame, in the described embodiment on the level of the rear frame 9 essentially on the same height level as the intermediate frame 10, onto which support means the interme­ diate frame 10 is transferred when removed from the roll combina­ tion. Moreover, on the removal side of the intermediate frame 10, in the described embodiment in the rear frame 9, transfer means 18 connected with the intermediate frame 10 are disposed, by means of which the intermediate frame is transferred from the roll combi­ nation into contact with the support means 17 and vice versa. The construction presented in the applicant's parallel patent application "Press section" also appears from the embodiment il­ lustrated in the drawing. The two rolls 3 and 5 included in the press section are both fixed to separate auxiliary frames 13, 14. The auxiliary frames 13, 14 are supported onto the shafts 19 and 20, which are fixed to the front frame 8 (shaft 19) and to the rear frame 9 (shaft 20). The ends of the auxiliary frames 13, 14 opposite with regard to the above points of attachment are fixed to the intermediate frame 10 by the fixing members 15, 16.

Claims: 1. Frame construction of the press section in a paper machine, the press section comprising a roll combination (1,2,3,4,5) the rolls of which form one or a plurality of nips (N1, N2, N3), members for guiding the paper web through the press section and members for guiding one or a plurlity of felts (6,7) into contact with the press section, the frame construction comprising a front frame (8), a rear frame (9) and an intermediate frame (10) connecting these two from above the press section, characterized in that the connections (11, 12) of the intermediate frame (10) both to the front frame and to the rear frame are disposed to be detach­ able in order to remove the intermediate frame from above the roll combination and in that the removal is disposed to be carried out essentially horizontally. 2. Frame construction of the press section according to claim 1 characterized in that the auxiliary frame (10) comprises at least one beam disposed in the longitudinal direction of the pa­ per machine, which is disposed on the side of the paper machine, and which comprises members (11a, 12a) disposed to cooperate in order to provide an interlocking between the countermembers (11b) in the front frame (8) on the one hand, and the countermembers (12b) in the rear frame (9) on the other hand. 3. Frame construction of the press section according to claims 1 and 2, characterized in that the auxiliary frame (10) is disposed to be displacable in the longitudinal direction of the paper machine in order to remove the intermediate frame (10) from above the roll combination. 4. Frame construction of the press section according to claims 1-3, characterized in that in the removal direction of the intermediate frame (10), support means (17) of the intermediate frame are disposed in the frame of the press section in order to support the intermediate frame (10) while this is removed from above the roll combination. 5. Frame construction of the press section according to claims 3 and 4, characterized in that transfer means (18) connected with the intermediate frame (10) are disposed on the removal side of the intermediate frame (10), by which transfer means the interme­ diate frame is displaced from above the roll combination onto the support means (17) and vice versa. 6. Frame construction of the press section according to claim 1, characterized in that the intermediate frame (10) consists of one piece. 7. Frame construction of the press section according to claim 4, characterized in that the support means (17) are placed in the rear frame (9).

Inventors: RANTALA, MAURI, SNELLMAN, YRJOE, Snellman, Yrjö
Applicants: OY TAMPELLA AB
Application year: 1988
Main classification: D21F3
IPC codes: D21F13