JPH08460B2 - Printing paper dryer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention relates to a printing paper printed with a high temperature drying printing ink,
The present invention relates to a dryer for drying printing paper printed with a low-temperature drying printing ink with hot air.

<Prior Art> A dryer for printing paper printed with high-temperature dry printing ink is provided with a drying chamber through which the strip-shaped printing paper sent from the high-speed offset printing machine passes, and a large number of nozzles for blowing hot air are provided in the drying chamber. It is provided across the printing paper path.

A hot-air circulation path is provided to heat the hot air blown from the nozzle to dry the printing paper through a heating device and a blower and supply the hot air again to the nozzle. A purifying passage is provided for purifying a part of the hot air in the hot air circulation passage through a purifying device equipped with a heating device and an oxidation catalyst and a blower, and discharging it to the atmosphere. A recirculation passage is provided for recirculating a portion of the purified high-temperature air in the purification passage to the hot air circulation passage through the on-off valve.

When the dryer is operated, first, in the purifying path, the purifying device is operated by ignition of the heating device, and the blower is operated to bring the printing paper into the state where the cleaning is immediately performed when the drying is started.

Next, while starting to feed the printing paper inserted in the printing paper passage of the printing chamber, in the hot air circulation passage, the blower is operated without igniting the heating device to circulate the wind and a part of the circulating wind. Is discharged to the atmosphere through the purifying passage, expelling the air staying in the hot air circulation passage, and opening the on-off valve of the return passage,
Purification of the purification path Part of the hot air is returned to the hot air circulation path.

In the hot air circulation path, after the staying air is expelled, the heating device is ignited, the hot air is circulated, and the printing paper being fed is dried by the hot air for drying blown out from the nozzle.

When the printing paper printed with the high temperature dry printing ink is dried, the temperature of the hot air for drying is adjusted within the range of 180 to 280 ° C in consideration of the feeding speed of the printing paper and the like.

<Problems to be Solved by the Invention> Recently, a printing ink that is dried at a low temperature of 100 ° C. or lower has been developed. When the printing paper printed with the low temperature drying printing ink is dried, the temperature of the hot air for drying must be adjusted within the range of 100 to 180 ° C.

Therefore, in order to dry the printing paper printed with the low temperature dry printing ink and the printing paper printed with the high temperature dry printing ink, the dryer can adjust the temperature of the hot air for drying in a wide range of 100 to 280 ° C. Must.

However, the conventional dryer is exclusively for high-temperature drying printing ink, and it is extremely difficult to adjust the temperature of the hot air for drying to a low temperature of about 100 to 180 ° C.

Therefore, since the hot air for drying cannot be adjusted to a low temperature for low-temperature dry printing ink, the printing paper printed with the low-temperature dry printing ink cannot be dried.

An object of the present invention is to solve the above conventional problems.

<Focus for solving the problem> In the dryer for printed paper, the heating device of the purification passage is always operating, and attention is paid to the high-temperature air flowing through the purification passage. I have an idea.

The hot air in the hot air circulation path is heated by the hot air in the purification path.

During high temperature drying, activate the heating device in the hot air circulation path,
The hot air in the hot air circulation path is heated by the heating device in the hot air circulation path and the high temperature air in the purification path, and the hot air for drying is heated to a high temperature of about 180 to 280 ° C for high temperature dry printing ink.

During low temperature drying, the heating device of the hot air circulation path is not operated, and the hot air of the hot air circulation path is heated only by the high temperature air of the purification path, and the drying hot air is 100 to 180 for low temperature dry printing ink.
Reduce the temperature to around ℃.

<Means for Solving the Problems> In the present invention, a nozzle for blowing hot air for drying the printing paper is provided in a drying chamber through which the printing paper passes, and the hot air for drying the printing paper is heated through a heating device and a blower. , A hot air circulation path to supply again to the nozzle, and a purification path that purifies a portion of the hot air that has dried the printing paper through a heating device and an oxidation catalyst and a blower and releases it to the atmosphere In this machine, the heat receiving passage of the heat exchanger is interposed in the hot air circulation passage, and the heat radiation passage of the above heat exchanger is interposed in the passage of the purification high temperature air in the purification passage, and the printing paper printed with high temperature dry printing ink is dried. During high temperature drying, the purifying passage heating device and hot air circulating passage heating device are activated, and the printing paper printed with low-temperature drying printing ink is dried.At low temperature drying, the purifying passage heating device is activated to heat the hot air circulating passage. Configuration that does not operate the device A dryer of the printing paper, characterized in that it has.

<Operation> In the present invention, since the heat receiving passage and the heat radiating passage of the heat exchanger are respectively interposed in the passages of the purified hot air in the hot air circulation passage and the purification passage, the hot air in the hot air circulation furnace is heated by the hot air in the purification passage. Heated by.

Drying the printing paper printed with high-temperature dry printing ink During high-temperature drying, the heating device in the purification passage and the heating device in the hot air circulation passage are activated, so the hot air in the hot air circulation passage heats the high temperature air in the purification passage and the hot air circulation passage. It is heated by the device and the hot air for drying becomes hot.

Drying the printing paper printed with low-temperature dry printing ink During low-temperature drying, the heating device in the purification passage is activated and the heating device in the hot air circulation passage is not operated, so the hot air in the hot air circulation passage is heated only by the high temperature air in the purification passage. The hot air for drying becomes low temperature.

<Effects of the Invention> In the present invention, the hot air for drying has a high temperature during high temperature drying and has a low temperature during low temperature drying. Therefore, the hot air for drying is suitable for drying printing paper printed with a high temperature drying printing ink. It is possible to adjust not only the temperature, but also the temperature suitable for drying the printing paper printed with the low temperature drying printing ink.

Therefore, not only the printing paper printed with the high temperature dry printing ink but also the printing paper printed with the low temperature dry printing ink can be dried.

<Example> The printing paper dryer of the present example is provided with a box-shaped drying chamber 1 on the printing paper delivery side of a high-speed offset printing machine (not shown), and as shown in the drawing, it is provided below the front end wall of the drying chamber 1. A horizontally long rectangular inlet 2 is provided, and a horizontally long rectangular outlet 3 is provided at the lower portion of the rear end wall of the drying chamber 1, so that the strip-shaped printing paper P passes through the lower portion of the drying chamber 1 from the inlet 2 to the outlet 3. The printing paper passage 4 is formed.

As shown in the figure, a large number of nozzles 5 are provided in a zigzag pattern in the lower part of the drying chamber 1 with the printing paper passage 4 sandwiched therebetween, and each nozzle 5 is opened toward the printing paper passage 4 so that each nozzle 5 The hot air supplied to the common hot air inlet 6 is blown out from each nozzle 5 toward the printing paper passage 4.

As shown in the drawing, at the position above the nozzle 5 in the drying chamber 1, one end of a duct 8 with a filter 7 interposed is opened into the drying chamber 1 and the other end of the duct 8 receives heat from a heat exchanger 9. It is connected to the inlet of the passage and the outlet of the heat receiving passage of the heat exchanger 9 is connected to the duct 10
Connect to the suction port of the blower 11, connect the discharge port of the blower 11 to the inlet of the heating device 14 with the duct 13 with the air volume adjusting valve 12 interposed, and connect the outlet of the heating device 14 with the duct 15 to each nozzle 5 in common. Is connected to the hot air inlet 6.

That is, the hot air blown out from each nozzle 5 to dry the printing paper P in the printing paper passage 4 and the heat receiving passage of the heat exchanger 9 and the blower.
A hot air circulation path is configured to be heated through 11 and the heating device 14 and supplied again to each nozzle 5.

In addition, as shown in the drawing, a duct 18 having a filter 16 and an air volume adjusting valve 17 is provided at a position above the nozzle 5 in the drying chamber 1.
One end of the fan is opened in the drying chamber 1, the other end of the duct 18 is connected to the suction port of the blower 19, and the discharge port of the blower 19 is the duct.
Connect to the inlet of the heating device 22 of the purification device 21 at 20, heating device
The oxidation catalyst 23 of the purification device 21 connected to the outlet of 22 is connected to the duct 24.
Is connected to the inlet of the heat dissipation passage of the heat exchanger 9, and the outlet of the heat dissipation passage of the heat exchanger 9 is connected to the duct through the air volume adjusting valve 25.
The duct 26 is connected to one end thereof, and the other end of the duct 26 is open to the atmosphere outside the drying chamber 1.

That is, a part of the hot air that has blown out from each nozzle 5 and dried the printing paper P in the printing paper passage 4 is passed through the fan 19, the purification device 21 including the heating device 22 and the oxidation catalyst 23, and the heat radiation passage of the heat exchanger 9. After that, it constitutes a purification channel that releases it to the purified atmosphere.

Further, as shown in the drawing, an opening / closing valve 28 is provided at a position above the nozzle 5 in the drying chamber 1 in a duct 27 branched from the duct 24 between the purification device 21 of the purification passage and the heat radiation passage of the heat exchanger 9. Then, when the end of the duct 27 is opened into the drying chamber 1 and the feeding of the printing paper P in the printing paper passage 4 is started, the opening / closing valve 28 is opened and a part of the purified high temperature air in the purification passage is dried. A recirculation path for recirculating into the chamber 1 is configured.

As shown in the drawing, an air flow rate adjusting valve 30 is interposed in a duct 29 branching from a position upstream of the opening / closing valve 28 of the duct 27 of the return passage, and the end of the duct 29 is opened to the atmosphere outside the drying chamber 1. ,
It constitutes a temperature control path.

When the printing paper dryer of this example is operated, the strip-shaped printing paper P sent from the high-speed offset printing machine is sequentially inserted into the inlet 2, the printing paper passage 4 and the outlet 3 of the drying chamber 1 and the purification passage. At, the purifying device 21 is operated by the ignition of the heating device 22, and the blower 19 is also operated.

Then, the air in the drying chamber 1 is filtered by the filter 16 and the air volume adjusting valve 1.
7. Blower 19 and heating device 22 of purification device 21 and oxidation catalyst 23
Becomes high temperature, passes through the heat dissipation passage of the heat exchanger 9, heats the heat exchanger 9, and is discharged to the atmosphere through the air flow rate adjusting valve 25. When the printing paper P starts to be dried, it is immediately purified. It is ready to be done.

Next, while the feeding of the printing paper P inserted into the printing paper passage 4 of the drying chamber 1 is started, the blower 11 is operated without igniting the heating device 14 in the hot air circulation passage.

Then, the air in the drying chamber 1 is filtered by the filter 7 and the heat exchanger 9
Through the heat receiving passage, the blower 11, the air volume adjusting valve 12 and the heating device 14 which is not ignited, and flows into each nozzle 5 from the hot air inlet 6.
From each nozzle 5, the printing paper passage 4 of the drying chamber 1 is blown toward the printing paper P being fed and circulates in the hot air circulation passage.

That is, the air circulating in the hot air circulation path expels the air accumulated in the hot air circulation path to perform pre-purge.

During the prepurge, the air circulating in the hot air circulation passage is heated by passing through the heat receiving passage of the heat exchanger 9 heated by the hot air in the purification passage, and the temperature rises.

Further, when the feeding of the printing paper P is started, the return path opening / closing valve 28
Is opened, and a part of the high-temperature air in the purification passage is recirculated into the drying chamber 1.

After the stagnant air in the hot air circulation path is expelled, the heating device 14 of the hot air circulation furnace is ignited, the air circulating in the hot air circulation path is heated by the heating device 14, and the hot air blown out from each nozzle 5 is further heated.

Then, the hot air blown out from the nozzle 5 further rises in temperature,
The temperature reaches 150 ° C in about one minute after the feeding of the printing paper P is started. That is,
The temperature of the hot air is very fast.

In the case of high temperature drying in which the printing paper P printed with the high temperature dry printing ink is dried at a high temperature, ignition of the heating device 14 in the hot air circulation path is continued, and the hot air circulating in the hot air circulation path is heated by the heating device 14 and the heat exchanger. That is, the hot air blown from each nozzle 5 is heated to the desired temperature within the range of 180 to 280 ° C. for high temperature drying.

The hot air temperature during high temperature drying is adjusted by adjusting the amount of heat generated by the heating device 14 in the hot air circulation path.

In the case of low-temperature drying in which the printing paper P printed with the low-temperature drying printing ink is dried at a low temperature, the hot air circulation passage heating device 14 is extinguished, and the hot air circulating in the hot air circulation passage is heated by the heat exchanger 9 or the high temperature air in the purification passage. The heated hot air is blown out from each nozzle 5 to a desired temperature within a range of about 100 to 180 ° C. for low temperature drying, for example, about 140 ° C.

The temperature of the hot air during low-temperature drying is adjusted by the air flow rate adjusting valve 30 in the temperature adjusting path that discharges part of the hot air in the return path to the atmosphere.
Adjust by opening.

In the dryer of this example, the hot air for drying blown out from the nozzle 5 has a temperature suitable for drying the printing paper printed with the high temperature drying printing ink in the case of high temperature drying, and has a low temperature in the case of low temperature drying. Since the temperature is suitable for drying the printing paper printed with the dry printing ink, not only the printing paper printed with the high temperature drying printing ink but also the printing paper printed with the low temperature drying printing ink can be dried.

[Brief description of drawings]

The drawing is a schematic view of a dryer for printed paper according to an embodiment of the present invention. 1: Drying room, 5: Nozzle 9: Heat exchanger, 11: Blower 14: Heating device, 19: Blower 21: Purification device, 22: Heating device 23: Oxidation catalyst, P: Printing paper

Claims (1)

[Claims] 1. A drying chamber through which the printing paper passes is provided with a nozzle for blowing hot air for drying the printing paper, and the hot air for drying the printing paper is heated through a heating device and a blower and is again supplied to the nozzle. In a dryer that has a path to purify a portion of the hot air that has dried the printing paper through a heating device and an oxidation catalyst and a blower to release it to the atmosphere, the hot air circulation path The heat exchange passage of the exchanger is interposed, the heat dissipation passage of the above heat exchanger is interposed in the passage of high temperature air for purification of the purification passage, and the cleaning passage is heated during high temperature drying to dry the printing paper printed with high temperature dry printing ink. The device and the heating device of the hot air circulation path are activated, and the heating device of the purification air path is activated and the heating device of the hot air circulation path is not activated during low temperature drying in which the printing paper printed with low-temperature dry printing ink is dried. Printing characterized by Of the dryer.