FI98741C - Track drying and control method and apparatus - Google Patents

Description

98741 1ί6)

METHOD AND APPARATUS FOR DRY DRYING AND CONTROL

The present invention relates to a method and an apparatus for simultaneously drying and inverting a surface-treated paper, board or textile web. The method is also suitable for printing machines.

When coating both sides of the paper simultaneously, supporting the web and changing the direction of travel becomes a problem as the coating tends to adhere to the rollers. The same problem also arises in one-sided paving when turning the track to the pavement side. Recently, reversing devices based on the air mattress and coanda effect have become more common after double-sided coating. Figure 1 shows a typical track flow after a double-sided coating device, where 1 is a turning device and 2 is an infrared dryer. Typically, the turning angle (α) is 5 ° .... 230 °.

After the inverter, the coating is dried with an infrared and / or fluidized bed dryer until the paper is touch dry. Cylinder drying can then be used. However, long clearances cause driveability problems. The long absorption time is also not good for the migration of binders.

Similarly, in printing presses, color adhesion to the rollers is a problem.

According to the present invention, the elements of the heat radiator are arranged inside a drying and turning device of the web (paper, cardboard or textile web), whereby two process devices are connected. This creates a method and a device in which the free traction can be shortened and the drying process starts faster.

/ The invention will now be described with reference to Figures 2 and 3, to which, however, the invention is not intended to be exclusively limited.

», 98741

Track drying and control method and device in which the radiator is heated with gas.

The paper, board or textile web is made to follow the radius of curvature of the dryer (Fig. 2) by air blowing (11): air is blown between the web and the dryer damper (12), causing the vacuum (w) in this space to follow the curvature of the device. The radius of curvature, the amount of blowing air and the bearing area of the damper are dimensioned in the same way as in the turning device according to the track speed, basis weight and driving tension.

Blowing air prevents the track from touching the device.

The radiator elements (13) are placed between the dampers guiding the path. The radiators use known infrastructure technology. Gas infrastructure manufacturers normally use a radiator about 200 mm long and 140 mm wide. The cross-sectional area of the combustion air duct (15) required in paper machine applications is about 0.02 m2 per row of radiators. The inlet (16) and exhaust air ducts (17) supporting the track are typically about 0.03 m2 per row of radiators. Ignition in the gas fracture is ensured by covering the radiator with a plate (14) or by pulling it further away from the track during ignition.

The air flow (11) can also be directed perpendicular to the path (w), whereby no coanda effect occurs. In this case, the air blowing keeps the track away from the dryer and the desired distance of the track from the dryer is determined by the track tension.

Electrically heated track drying and turning method and device, * In the electrically heated paper, board or textile web drying and turning method (Fig. 3), the radiator surface can be a radiator glass (21). However, the use of glass as a support surface is not necessary, but the radiator can be placed in the same way as in a gas frother (Fig. 2, part 13). the radiator

Claims (9)

1. The drying and guiding operation of the web, in which the coated paper, cardboard or textile web is phase to follow the pivotal shape of the dryer (Figure 2) with the aid of the coanda phenomenon caused by the air bubble (11), which is known in the art: The air is biases between the web of the dryer and the dryer (12) or the protective glass of the dryer (21, figure 3), either in the direction of the web or towards the path of the web. In individual transverse directions common to the web in perpendicularly directed blowers that streamline drying, it can be ensured that the web does not touch the dryer. The process is characterized in that, at the same time, it is dried with known straining drying and turned with the aid of air-blown paper, cardboard or textile web. Method according to claim 1, characterized in that the path direction of the web can be changed 5 ... 230 degrees. The method according to any of claims 1-2, characterized in that the radiator (figure, part 13) is heated with gas. 4. A method according to any one of claims 1-2, characterized in that the source of energy needed for the dryer is electricity. 5. A method according to any one of claims 1-2, characterized in that on the opposite side of the web a corresponding radiator, counter reflector or support fan can be found. 6. The web drying and control device, where coated paper, cardboard or textile web is fastened to follow the pivotal shape of the dryer (Figure 2) by means of the coanda phenomenon caused by the air blower (11), which is known in the art. The air is biased between the track plate of the web and the dryer (12) or the protective glass of the dryer (21, figure 3), either in the direction of the web or in the direction of the web. In individual transverse directions common to the web in perpendicular blowers that make the drying more efficient, it can be ensured that the web does not touches wipers. 6 (6) 98741 Apparatus is characterized in that in the same device it is both dried by straining and reverses the path direction of the web. n Device according to claim 6, characterized in that the radiator's energy source is gas or electricity. 8. A device according to claim 6, characterized in that gas is a source of energy and that the ignition of the gas is secured by covering the radiator with discs or by pulling the radiator further from the web. Device according to any of claims 6-8, which reverses the path direction of the path 5 ... 230 degrees.