JPH0317971Y2 - - Google Patents

Description

[Detailed description of the invention] This invention is a printing machine such as a rotogravure printing machine or an offset rotary printing machine, or a coating machine such as a coating machine or a laminator, for printing or coating on a continuous strip of paper, film, etc. The present invention relates to a hot air nozzle used in a drying device for drying or heat-treating the air after drying.

Conventionally, this type of drying equipment has generally been of the nozzle jet type, which blows hot air at high speed at right angles to the object to be dried, in order to quickly dry the moving strip (hereinafter referred to as the object to be dried). As shown in FIG. 1, this type of drying apparatus has a large number of hot air nozzles 2, which are slit nozzles, arranged in a space surrounded by a drying hood along the direction in which the material to be dried 1 is transported. Note that 3 in the figure is a guide roller. In this drying apparatus, hot air blown from a hot air nozzle 2 hits the surface of the object 1 to be dried, then divides into left and right sides and flows along the surface of the object 1 to be dried. Therefore,
Hot air emitted from a nozzle near the inlet/outlet section 4 (only the outlet section is shown in the figure) of the object to be dried flows along the surface of the object to be dried, and leaks out from the inlet/outlet section 4 to the outside. In order to prevent such hot air leakage, the second
As shown in the figure, a suction part 5 is provided in the vicinity of the entrance/exit part 4, or as shown in FIG. things are known. However, the device equipped with the suction section 5 shown in FIG. 2 sucks the air flowing out along the surface of the material to be dried from above, and therefore cannot prevent the outflow unless it sucks in more air than necessary. On the other hand, the one using the inclined slit nozzle 6 shown in FIG. Because it is sprayed, it has the disadvantage that the heat transfer performance of hot air is significantly lower than that of spraying at right angles, to less than half that.

The present invention solves these drawbacks and creates a new system that can prevent air from flowing out at the entrance and exit without requiring a suction section to exhaust air or using an inclined nozzle to reduce heat transfer performance. The purpose is to provide a hot air nozzle with a structure.

The hot air nozzle of the present invention includes a slit nozzle that blows hot air toward the object to be dried at an angle in a direction away from the inlet/outlet section, and a slit nozzle that is provided on the opposite side of the inlet/outlet section of the slit nozzle to spot the hot air onto the object to be dried. It is characterized by being constructed with a perforated plate nozzle that sprays the air in a straight line and at right angles.

Hereinafter, embodiments of the present invention shown in FIG. 4 and subsequent figures will be described. In FIG. 4, an entrance/exit portion 4 for the material to be dried 1 into the space surrounded by the drying hood of the drying device.
The hot air nozzle 7 of the present invention is provided near the outlet (in the drawing, it is the outlet, but it may be the inlet). As shown enlarged in FIGS. 5 and 6, this hot air nozzle 7 includes a slit nozzle 8 that blows hot air onto the material to be dried 1 at an angle away from the inlet/outlet part 4, and an inlet/outlet part 4 of the slit nozzle 8. and a perforated plate nozzle 9 provided on the opposite side (the right side in FIG. 5). The perforated plate nozzle 9 has a large number of hot air blowing holes 10, and these holes 1
The arrangement is such that hot air blown from zero is blown at right angles to the object 1 to be dried in a spot shape. This perforated plate nozzle 9 blows hot air directly under each hot air blowing hole 10 at high speed to create a large number of areas each having a small area but with a large heat transfer coefficient. The average heat transfer coefficient can be improved. In order for the perforated plate nozzle 9 to exhibit good performance, it is preferable that the hole diameter of each hot air blowing hole 10 be 3 to 6 mm, the hole interval to be 15 to 45 mm, and the hot air blowing speed from the hole to be 20 mm.
It is preferable to set it as 50 m/s.

The hot air nozzle 7 of the present invention having the above configuration can blow a part of the hot air obliquely onto the object 1 to be dried using the slit nozzle 8, and can prevent the wind from flowing out along the object 1 to be dried. The remaining hot air is blown at right angles to the material to be dried 1 through the perforated plate nozzle 9.
This has an excellent effect in that the average heat transfer coefficient can be improved, and the heat transfer performance can be improved far more than in the case where the entire amount of hot air is blown obliquely from the nozzle 6 as shown in FIG.

The embodiment shown in FIG. 4 is the hot air nozzle 7 of the present invention.
was used in a drying device equipped with a large number of slit nozzles 2 along the direction of transport of the material to be dried, but the hot air nozzle 7 can be used in various types of hot air drying devices, for example, as shown in FIG. It can also be used in a drying apparatus in which perforated plate nozzles 11 and exhaust channels 12 are arranged alternately along the direction of transport of the material to be dried 1. This perforated plate nozzle 11 has almost the same dimensions as the perforated plate nozzle 9 of the hot air nozzle 7 of the present invention.
A nozzle that has hot air blowing holes spaced apart and can exhibit better heat transfer performance than conventional slit nozzles by blowing out hot air at a higher speed than these hot air blowing holes, for example at 20 to 50 m/s, and colliding with the material to be dried. It is. When the perforated plate nozzle 11 and the hot air nozzle 7 of the present invention are used together, not only can the heat transfer performance be improved, but also the hot air blowing speed from each perforated plate nozzle can be made uniform and easily adjusted to the desired speed. There are advantages.

[Brief explanation of the drawing]

1 to 3 are schematic side sectional views showing a part of a conventional drying device, FIG. 4 is a schematic side sectional view showing a part of a drying device equipped with a hot air nozzle 7 of the present invention, and FIG. 6 is a bottom view of the hot air nozzle 7, and FIG. 7 is a schematic side sectional view showing another example of a drying device equipped with the hot air nozzle 7 of the present invention. be. 1... Material to be dried, 4... Inlet/outlet section, 7... Hot air nozzle, 8... Slit nozzle, 9... Perforated plate nozzle.

Claims (1)

[Scope of utility model registration request] In a hot air nozzle provided near the entrance/exit of an object to be dried to a space surrounded by a drying hood of a hot air drying device of a printing machine or a coating machine, the hot air nozzle 7 directs hot air to the object 1 to be dried at the entrance/exit section. 4, and a perforated plate nozzle 9 provided on the opposite side of the inlet/outlet portion of the slit nozzle 8 and blowing hot air spot-likely and at right angles onto the material to be dried. A hot air nozzle characterized by: