TECHNICAL FIELD

The invention relates to a paper or board machine.

The arrangement according to the invention relates to a passage space between the drive side and the tending side of a paper or board machine.

In one advantageous embodiment of the invention, the passage space is also formed into an automation space, thus enabling it to be used for placement of machine control system components or other equivalent components. In this connection, the machine control system comprises all systems associated with the control of the machine, such as systems of machine control, process control, quality control, measurement, and monitoring.

BACKGROUND ART

In the state-of-the-art paper or board machines, maintenance and operating staff cannot walk safely in the operating situation of the machine between the drive side and the tending side of the machine at the wet end of the machine (forming and press sections). Cramped spaces, high moisture content and splashes, as well as moving parts, such as rolls and felts, at the wet end constitute a great risk situation for the maintenance and operating staff walking on open service bridges across the machine. For this reason, the maintenance and operating staff may need to go around the paper or board machine when the machine is running in order to get safely from the tending side of the machine to the drive side of the machine and vice versa.

In the state-of-the-art paper or board machines the process control units and input/output units associated with the machine control system are generally placed in a closed electrical compartment outside the parts of the machine.

The locating of electrical control devices particularly at the wet end of a paper or board machine is problematic. The reliability of operation, accessibility and maintainability of sensitive electronic devices become a problem in the cramped spaces and stringent environmental conditions of the wet end. For this reason, a closed electrical compartment has been used which is located separately from the machine parts of the wet end and in which control units and input/output units can be protected more easily from moisture, temperature variations and other load from the environment. Cables connected to each device to be controlled are passed from this closed electrical compartment to the assembly groups of the paper or board machine (a headbox, a wire section, a press section, a dryer section, coating units and finishing machines). Therefore, the distance to the object to be controlled becomes long.

The cabling work between the closed electrical compartment and the control devices in the assembly groups of the machine is done on the installation site of the paper or board machine. The installation work includes construction of cable routes, drawing of main cables and device cables, connecting of cable ends and testing of cable connections. The above-mentioned cable installation and connecting work is done after the mechanical installation of the machine and it considerably prolongs the timetable of installation of the paper or board machine.

FI patent 106477 discloses one integrated machine control system in which process control units and/or input/output units of the machine control system are placed in connection with an assembly group of a paper or board machine in a control cabinet located on the tending or drive side of the machine.

FI patent 106478 discloses one integrated machine control module including process control units and/or input/output units of a machine control system. These units are placed in an internal cabinet located in connection with an assembly group of a paper or board machine in a control cabinet placed on the tending or drive side of the machine.

SUMMARY OF INVENTION

The arrangement according to the invention is mainly characterized by what is stated in the characterising part of claim 1.

By arranging in a paper or board machine a passage space which extends from the tending side of the machine to the drive side of the machine and which is closed in machine direction, a safe passageway protected against ambient conditions is achieved between the tending side and the drive side of the machine at the wet end of the machine.

When said passage space is additionally formed into an automation space, a protected automation space for process control units and input/output units as well as for other equivalent devices is obtained close to the actuating means to be controlled. The cabling between the input/output units and the actuating means to be controlled is shortened in this arrangement to a significant extent. Shorter cables also reduce the amount of work needed for installation. Hence, it is also possible to shorten the total time taken by paper or board machine installation or to reduce the timetable limitations arising from work orders. This kind of combined protected passage and automation space can be equipped and tested in advance at the paper machine factory, which means that only the installation of the cabling between the input/output units and the actuating means to be controlled remains for the start-up installation of the machine. Cabling is additionally needed for the voltage supply and for the bus connection between a part of the centralised system and the closed automation space.

In the closed automation space it is also possible to install, when needed, control units for hydraulic or pneumatic actuators, or other equivalent units.

The protected automation space can be air-conditioned and, when needed, cooled such that temperature and humidity conditions suitable for electronic components prevail there. In addition, ventilation can be provided with filtering to filter out the impurities present in the air surrounding the automation space. It is possible to prevent the vibrations transmitted from the frame of the paper or board machine to the frame of the automation space from propagating to the electronic components, for example, by attaching the cabinets containing the electronic components by means of vibration dampers to the automation space. The operating staff can carry out safely necessary monitoring and maintenance operations in this kind of protected automation space while the machine is running.

BRIEF DESCRIPTION OF FIGURES

In the following, the invention will be described in detail with reference to the exemplifying embodiments shown in the figures of the appended drawing, to the details of which embodiments the invention is not meant to be limited.

Figure 1 is a schematic view of a press section of a paper machine showing a passage space in accordance with the invention.

Figure 2 is a schematic cross-sectional view of the passage space in accordance with the invention.

Figure 3 is a schematic longitudinal sectional view of the passage space in accordance with the invention.

Figure 4 shows, in block diagram form, one machine control system of a paper machine.

Figure 5 shows, in block diagram form, another machine control system of a paper machine.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Fig. 1 schematically shows a press section of a paper machine and two closed passage spaces 10OA, IOOB extending from the tending side HP of the machine to the drive side KP of the machine.

Fig. 2 is a cross-sectional view of the passage space 100 shown in Fig. 1 and Fig. 3 is a longitudinal sectional view of the passage space 100 shown in Fig. 1. The passage space 100 comprises a floor surface 101, a ceiling surface 102, a first side wall 103, and a second side wall 104. The upright trapezoidal shape of the second side wall 104 is mainly determined by the space available at the site of installation. Boxes 200A...200F are attached to the second side wall 104 of the passage space 100, and automation devices can be placed in said boxes. The height h of the passage space 100 is such that there is room for the operating staff to walk straight in it. The width 1 of the passage space in machine direction is in turn such that a sufficient free working space remains for the operating staff between the boxes 200 A...200F and the rear wall 103. The above-mentioned criteria can be met, for example, by a passage space whose height h is about 2.2 m and whose width 1 in machine direction is about 1.4 m. It is advantageous to dimension the outside measurements of the passage space 100 such that the passage space 100 can be accommodated in a normal size transport container, whose free interior space has a height of about 2.4 m, a width of about 2.3 m and a length of about 12 m.

The passage space 100 comprises, at its both ends, support beams 110, 111, by means of which the passage space is attached to the frame structures of the tending side HP and the drive side KP, respectively. At both ends of the passage space 100 there is an entrance space having a door 105, 106 opening in machine direction. Through this door 105, 106 there is access to a service platform extending from the tending side HP of the machine to the drive side KP of the machine, and from this platform it is possible to perform maintenance operations on a roll located in front of said service platform. This entrance space is open to the tending side HP and, correspondingly, to the drive side KP, and a door 107 leads from it to a closed portion of the passage space. The closed portion of the passage space 100 is thus closed by a door at its both ends.

In the structures of the passage space 100, for example, in its ceiling structures it is also possible to place tubes 300 extending from the tending side HP of the machine to the drive side KP of the machine, which tubes can be hydraulic or pneumatic tubes or tubes for protecting cables. The hydraulic or pneumatic devices of the drive side KP can be connected by means of these tubes 300 to the devices or input/output means of the tending side HP.

When the passage space 100 is attached by means of the support beams 110, 111 provided at both ends of the passage space to the frame structures of the machine, the passage space also forms part of the frame structure of the machine.

The passage space 100 forms one container during transport and it can be provided already at the paper machine factory with necessary devices, cables, tubes, etc. The prefabrication degree of the passage space 100 can thus be made high. The passage space offers good protection for people and devices in the passage space in case of damage of a machine component or a fabric.

The passage space 100 can also be formed, for example, inside a cantilever beam. In a situation where the passage space need not carry the loads of the frame, the

walls of the passage space can be made, for example, of a composite material. If higher strength is required, it is possible to use steel in the walls and to dimension the structure to carry the load like a cross bream. The inner surface of the walls can also be insulated electrically, when needed, in particular under devices that require electrical insulation. The inner and/or outer surface of the passage space 100 can also be heat and/or sound insulated. The outer and/or inner surface of the passage space 100 can also be coated with a suitable material to better withstand the ambient conditions. The outer and/or inner surface of the passage space or some part of them can also be provided with heating to prevent condensation, hi the walls of the passage space it is also possible to arrange monitoring openings provided with glass or equivalent transparent material, through which openings the operating staff is able to monitor the process while the machine is running.

In the embodiments shown in the preceding figures, the passage space is closed by means of the doors 107 at the ends of the passage space 100, but in some cases the doors 107 can also be replaced with air curtains. The passage space 100 is closed in any case in the machine direction between the tending side HP and the drive side KP.

In the embodiments shown in the preceding figures there are entrance spaces at both ends of the passage space. It may also be contemplated that there is an entrance space only at either end or that there are no entrance spaces at all. From the entrance spaces it is also possible to easily arrange an entry to a service platform situated adjacent to the passage space and extending from the tending side to the drive side.

The preceding figures show one advantageous shape of the passage space suitable for a certain press section, but the invention is naturally not limited to this kind of shape. In principle, the cross-sectional shape of the passage space can be any shape, such as a polygon, a rectangle, a circle, an ellipse, or a combination of these, etc. The location of the passage space in the machine and the devices

around the location, such as felts and rolls, set limitations on the shape of the passage space.

It is also advantageous to form the passage spaces 10OA, IOOB into automation spaces, placing in them the process control units PCS and the input/output units I/O of each assembly group of the machine control system. In the passage spaces 10OA, IOOB it is also possible to place hydraulic, pneumatic, lubricating, vibration control and electronic components associated with the machine control system, as well as frequency converters, PLC devices, operation panels, PC devices and amplifiers. The devices placed in the passage space 100 are used for controlling and/or measuring and/or monitoring, for example, electric, hydraulic or pneumatic actuating means, such as control valves, limit switches, pressure transmitters, temperature transmitters, vibration sensors, position sensors, etc.

Fig. 4 shows one machine control system of a paper or board machine in block diagram form. The machine control system includes process control units PCS and input/output units I/O as well as a data communication bus C connecting the process units PCS. There is a cable connection Ll... Ln from the input/output units I/O to assembly groups U ₁ ... U _n of the paper machine. The cabling Ll... Ln can comprise tens or hundreds of conductor pairs, in which a digital and/or analog signal passes. The control cabling Ll ... Ln is a bidirectional cabling, in which control signals are transmitted from an input/output unit I/O to a device to be controlled and monitoring signals are transmitted from the device to be controlled to the input/output unit I/O. The assembly groups U ₁ ... U _n of the paper machine include, for example, a headbox, a wire, a press, a dryer section, coating units and finishing machines. The machine control system controls actuating means located in these, for example, valves or pneumatically operated members. The controllable actuating means located in each assembly group Ui... U _n are denoted with reference numerals D ₁ i...Di _m ; ...; D _n i...D _n m- The connection between the process control units PCS and the input/output units LO is provided by a data communication bus C The process control units PCS may include programmable

logics and/or computers. In the state-of-the-art arrangements, the process control units PCS and the input/output units I/O of the machine control system are placed in a separate closed space outside the machine (area A indicated by a broken line). In the preferred embodiment of the invention, at least one input/output unit I/O located in the area A is placed in the passage space 100. It is advantageous to place in the passage space 100 all the automation devices located in the area A and associated with the machine assembly groups located in the vicinity of said passage space 100.

Fig. 5 shows, in block diagram form, one variant of the machine control system of a paper or board machine illustrated in Fig. 4. In this state-of-the-art arrangement, the process control units PCS and the input/output units I/O are placed in protected spaces (broken line areas Bi...B _n ) located in connection with assembly groups U ₁ ... U _n of the paper machine. A data communication bus C, which forms a connection between the process control units PCS and the other parts of the machine control unit, is passed to the process control units PCS in the protected space Bi...B _n located in connection with each assembly group U ₁₁₁₁ U _n . The connection between the process control units PCS and the input/output units I/O is provided by a data communication bus C The process control units PCS placed in each assembly group Ui... U _n also communicate with one another through the data communication bus C. Said protected spaces can be boxes placed on the side of the assembly groups, for example, on the tending side. In the preferred embodiment of the invention, all the automation devices of the areas B _{111 1} B _n associated with the assembly groups in the vicinity of said passage space 100 are placed in the passage space 100.

The various details of the invention may vary within the inventive idea defined by the claims set forth below and differ from those given above by way of example only.