JP4579698B2 - Temperature control device for printing paper drying equipment - Google Patents

Description

  The present invention relates to a technique for controlling hot air temperature in an apparatus that dries printing paper with hot air.

  In the web printing line, the belt-shaped printing paper is printed by passing through a high-speed offset printer, heated in hot air of a drying device, heated, and the printing ink is dried and cooled by passing through a cooling device. The

  The drying device has a drying chamber between the printing press and the cooling device. The drying chamber has a box shape and is provided with a horizontally long inlet at the front end wall and a horizontally long outlet at the rear end wall, and forms a printing paper path in the front-rear direction from the inlet to the outlet. The drying chamber elongated in the front-rear direction divides the inlet and outlet into a plurality of areas. For example, it is divided into a first zone on the inlet side and a second zone on the outlet side.

  In the first area, nozzles for blowing hot air toward the printing paper path are provided above and below the printing paper path. Moreover, the hot air supply path which heats air and supplies it to a nozzle is provided. The hot air supply path opens the suction port of the blower into the area, connects the discharge port of the blower to the inlet of the heating device, and connects the outlet of the heating device to the nozzle. The heating device is a burner device that burns fluid fuel. This apparatus adjusts the flow rate of the fuel supplied to the burner to increase or decrease the thermal power, and adjust the temperature of the hot air supplied to the nozzle. Similarly to the first area, the second area is also provided with a nozzle and a hot air supply path. A temperature control device is provided for controlling the hot air temperature in the first zone and the second zone.

  The first section on the inlet side is provided with a thermocouple for detecting the temperature of hot air supplied from the hot air supply path to the nozzle, and a contact-type temperature sensor. The temperature control device increases or decreases the flow rate of the fuel supplied to the heating device in the first zone, that is, the hot air temperature in the first zone, so that the hot air temperature detected by the contact temperature sensor becomes a preset value.

  The second area on the outlet side is provided with an infrared detection sensor and a non-contact type temperature sensor for detecting the paper surface temperature of the running printing paper in a non-contact manner outside the outlet of the drying chamber. The temperature control device increases or decreases the flow rate of the fuel supplied to the heating device in the second zone and the hot air temperature in the second zone so that the paper surface temperature detected by the non-contact temperature sensor becomes a preset value.

  The setting value of the hot air temperature in the first zone and the setting value of the paper surface temperature of the printing paper coming out from the outlet of the drying chamber are determined by the operator based on the ink amount of the printing paper, the paper quality, the dwell time in the drying chamber, and the like.

JP 2004-330560 A

  The printing quality of printing paper is affected by the paper surface temperature and hot air temperature during hot air drying that evaporates the solvent of the printing ink adhering to the printing paper.

  However, in the printing paper drying apparatus as described above, when the paper surface temperature of the printing paper that has come out from the outlet of the drying chamber fluctuates for some reason, the hot air in the second section, that is, the downstream end section on the outlet side of the drying chamber. The temperature rises and falls according to the paper surface temperature of the printing paper, but the hot air temperature in the first zone on the inlet side of the drying chamber, that is, the upstream zone on the upstream side of the downstream end zone remains at a preset constant value, and printing Does not rise or fall according to the paper surface temperature.

  Even if the paper surface temperature of the printing paper fluctuates, if the hot air temperature in the upstream section of the drying chamber remains at a constant value, the printing paper will be overheated or insufficiently heated while passing through the upstream section. Print quality deteriorates. Not optimal.

  Therefore, a non-contact type temperature sensor that detects the paper surface temperature of the running printing paper in a non-contact manner is disposed in the upstream area of the drying chamber, and the upstream region is determined according to the paper surface temperature detected by the non-contact temperature sensor. It is conceivable to control the hot air temperature. However, the upstream area of the drying chamber is hot. There is no practical non-contact temperature sensor that can be used in the high temperature atmosphere of the drying room.

1) The drying chamber forms a printing paper path from the inlet to the outlet, and divides the area between the inlet and the outlet into a plurality of areas. Each area has a nozzle and a hot air supply path for blowing hot air toward the printing paper path. In the drying device where the hot air temperature can be adjusted, the strip-shaped printing paper runs through the printing paper path and sequentially passes through each area, and each area receives hot air,
In the downstream end area on the outlet side of the drying chamber, a non-contact type temperature sensor that detects the paper surface temperature of the running printing paper is provided outside the outlet of the drying chamber, and the surface temperature detected by this non-contact type temperature sensor is the paper surface. A device for controlling the temperature of the hot air in the downstream end area is provided so that the temperature is set, and a contact-type temperature sensor for detecting the hot air temperature in the downstream end area is provided.
The upstream section upstream of the downstream end section of the drying chamber is provided with an upstream section contact temperature sensor that detects the hot air temperature in the upstream section, and the upstream section contact temperature sensor detects the upstream section contact temperature sensor. A device was installed to control the hot air temperature in the upstream area so that the difference between the hot air temperature and the hot air temperature in the downstream edge area detected by the contact-type temperature sensor in the downstream edge area becomes the set value of the hot air temperature difference. A temperature control device characterized by.

2) In the above device,
The drying chamber is characterized by dividing the space between the inlet and outlet into a first zone on the inlet side and a second zone on the outlet side, with the second zone being the downstream end zone and the first zone being the upstream zone. And

3) In the above device,
The hot air temperature in the downstream end area is higher than the set value of the paper surface temperature of the printing paper,
The hot air temperature in the upstream area is higher than the hot air temperature in the downstream end area.

  The hot air temperature in the downstream end area is controlled so that the paper surface temperature of the printing paper coming out from the outlet of the drying chamber becomes the set value of the paper surface temperature. The hot air temperature in the upstream area is controlled so that the difference from the hot air temperature in the downstream end area becomes a set value of the hot air temperature difference. Therefore, the hot air temperature in the upstream area is controlled according to the paper surface temperature of the printing paper that has exited from the outlet of the drying chamber.

  When the paper surface temperature of the printing paper coming out from the outlet of the drying chamber deviates downward or upward from the set value of the paper surface temperature, the hot air temperature in the downstream end region increases or decreases, and the hot air temperature in the upstream region also increases or decreases. The printed paper is less likely to overheat or underheat while passing through the upstream section. Print quality is unlikely to deteriorate.

  In the printing line, a high-speed offset printing machine, a drying device, and a cooling device are sequentially arranged. In a high-speed offset printing machine, a strip-shaped paper is drawn out from a web, and the paper is printed through a printing roller. The strip-shaped printing paper delivered from the printing machine passes through the drying device at high speed and is heated with hot air, and the printing ink adhering to the paper surface is dried. The printing paper heated by the drying device passes through the cooling device and is cooled.

  The drying device is provided with a drying chamber 1 between the printing press and the cooling device. As shown in FIG. 1, the drying chamber 1 has a box shape, and is provided with a horizontally-long rectangular inlet 2 on the front end wall and a horizontally-long rectangular outlet 3 on the rear end wall, and extends in the front-rear direction from the inlet 2 to the outlet 3. A printing paper path 4 is formed. The strip-shaped printing paper a sequentially passes through the inlet 2, the printing paper passage 4, and the outlet 3 of the drying chamber 1.

  The drying chamber 1 having a rectangular parallelepiped shape elongated in the front-rear direction equally divides the space between the inlet 2 and the outlet 3 into two areas. The drying chamber 1 is divided into a first zone 5 on the inlet 2 side and a second zone 6 on the outlet 3 side. The second area 6 on the outlet 3 side is a downstream end area of the drying chamber 1. The first area 5 on the inlet 2 side is an upstream area adjacent to the upstream side of the downstream end area 6.

  In the first area 5, first nozzles 7 that blow hot air toward the printing paper path 4 are provided above and below the printing paper path 4. Further, first hot air supply paths 8 and 9 for supplying air to the first nozzle 7 by heating the air are provided. The first hot air supply paths 8 and 9 open the suction port of the first blower 8 into the first section 5, connect the discharge port of the first blower 8 to the inlet of the first heating device 9, and the first heating device Nine outlets are connected to the upper and lower first nozzles 7.

  The 1st heating apparatus 9 is a burner apparatus which burns the fluid fuel of gaseous fuel or liquid fuel. The burner is connected to the fuel supply path. The first supply flow control valve 10 is interposed in the fuel supply path. The first flow control valve 10 adjusts the fuel supply flow rate to increase or decrease the burner thermal power. The temperature of the hot air supplied to the first nozzle 7 is adjusted by increasing or decreasing the heating power. The hot air temperature can be adjusted. A first thermocouple and a first contact temperature sensor 11 for detecting the temperature of hot air supplied from the first heating device 9 to the first nozzle 7 are provided.

  The second zone 6 also has the same second nozzle 12, second blower 13 and second heating device as the first hot air supply path comprising the first nozzle 7, first blower 8 and first heating device 9 in the first zone 5. 14 is provided with a second hot air supply path. The second heating device 14 is a burner device similar to the first heating device 9. A second flow rate control valve 15 is interposed in the fuel supply path of the burner. The hot air temperature can be adjusted. A second thermocouple and a second contact type temperature sensor 16 for detecting the temperature of hot air supplied from the second heating device 14 to the second nozzle 12 are provided.

  Outside the outlet 3 of the drying chamber 1, a non-contact type temperature sensor 17 that detects the surface temperature of the running printing paper a in a non-contact manner is provided. The non-contact type temperature sensor 17 is an infrared detection sensor that detects the infrared light emitted from the paper surface of the printing paper a and measures the paper surface temperature of the printing paper a.

  Temperature control devices 18 and 19 for controlling the hot air temperature in the first zone 5 and the hot air temperature in the second zone 6 are provided. The temperature control devices 18 and 19 connect the output end of the setting unit 18 to the input end of the control unit 19. The control unit 19 connects the output terminals of the non-contact temperature sensor 17, the first contact temperature sensor 11, and the second contact temperature sensor 16 to the input terminals. The control unit 19 has a first output end connected to the first flow control valve 10 and a second output end connected to the second flow control valve 15.

  When operating the drying device, the blower 8 and the heating device 9 in the first hot air supply path and the blower 13 and the heating device 14 in the second hot air supply path are operated. When the printing line is activated, the printing paper a passing through the drying device travels through the printing paper passage 4 of the drying chamber 1 and sequentially passes through the inlet 2, the first zone 5, the second zone 6 and the outlet 3.

  When the printing paper a passes through the first area 5, hot air from the first hot air supply passages 8 and 9 is blown from the upper and lower first nozzles 7 to the upper surface and the lower surface, and when passing through the second area 6, Hot air from the second hot air supply passages 13 and 14 is blown onto the lower surface from the upper and lower second nozzles 12. The printing ink adhering to the upper and lower surfaces of the printing paper a is heated with hot air, and the solvent is evaporated and dried. Further, as shown in FIG. 2, the paper surface temperature of the printing paper a is about room temperature when passing through the entrance 2, rapidly increases when passing through the first section 5, and becomes high when passing through the second section 6 and when passing through the exit 3. High temperature is almost maintained.

  Before the operation of the drying device, the paper surface temperature t of the printing paper “a” immediately after coming out from the outlet 3 is set in the setting unit 18 of the temperature controller. The paper surface temperature t is the temperature at the paper surface position measured by the non-contact temperature sensor 17.

  Further, a difference ΔT between the hot air temperature T in the second section 6 and the hot air temperature T + ΔT in the first section 5 is set. The hot air temperature in the second zone 6 is the temperature of the hot air supplied from the second hot air supply passages 13 and 14 to the second nozzle 12, that is, the temperature measured by the second contact temperature sensor 16. The hot air temperature in the first zone 5 is the temperature of the hot air supplied from the first hot air supply paths 8 and 9 to the first nozzle 7 and the temperature measured by the first contact temperature sensor 11.

  The setting value t of the paper surface temperature of the printing paper a and the setting value ΔT of the hot air temperature difference between the second zone 6 and the first zone 5 are determined by the operator according to the ink amount of the printing paper a, the quality of the paper, the residence time of the drying chamber, etc. Determine based on. When the paper surface temperature of the printing paper a immediately after exiting from the outlet 3 is about 120 ° C., the hot air temperature in the second section 6 is about 180 ° C., and the hot air temperature in the first section 5 is about 200 ° C., When the print quality is optimal, the setting value t of the paper surface temperature of the printing paper a is “120 ° C.”, and the setting value ΔT of the hot air temperature difference between the second zone 6 and the first zone 5 is “+ 20 ° C.” Set.

  During the operation of the drying device, the controller 19 of the temperature control device uses the second flow control valve 15 to set the second heating device so that the paper surface temperature measured by the non-contact temperature sensor 17 becomes the paper surface temperature set value t. 14 is adjusted to control the hot air temperature T in the second zone 6. For example, when the set value t of the paper surface temperature is about 120 ° C., the hot air temperature T in the second section 6 is about 180 ° C.

  In addition, the control unit 19 sets the hot air temperature measured by the first contact temperature sensor 11 to be higher by the set value ΔT of the hot air temperature difference than the hot air temperature T measured by the second contact temperature sensor 16. The fuel supply flow rate of the first heating device 9 is adjusted by the 1 flow rate control valve 10 to control the hot air temperature in the first section 5. For example, when the set value t of the paper surface temperature is about 120 ° C. and the set value ΔT of the hot air temperature difference is about + 20 ° C., the hot air temperature T + ΔT of the first section 5 is about 200 ° C.

  When the paper surface temperature measured by the non-contact temperature sensor 17 deviates downward from the paper surface temperature set value t for some reason, the second flow control valve 15 increases the fuel supply flow rate of the second heating device 14. The hot air temperature T in the second zone 6 rises. The paper surface temperature of the printing paper a passing through the second area 6 and the outlet 3 increases. The paper surface temperature measured by the non-contact type temperature sensor 17 rises and returns to the set value t of the paper surface temperature.

  Conversely, when the temperature measured by the non-contact temperature sensor 17 deviates upward from the set value t of the paper surface temperature, the second flow rate control valve 15 decreases the fuel supply flow rate of the second heating device 14 and the second zone 6 The hot air temperature T decreases. As for the printing paper a passing through the second area 6 and the outlet 3, the paper surface temperature decreases. The measured temperature of the non-contact temperature sensor 17 decreases and returns to the set value t of the paper surface temperature.

  When the hot air temperature T in the second area 6 and the hot air temperature T measured by the second contact temperature sensor 16 rise, the hot air temperature T, the hot air temperature in the first area 5, and the measured temperature of the first contact temperature sensor 11 Is deviated downward from the set value ΔT of the hot air temperature difference. Then, the 1st flow control valve 10 increases the fuel supply flow rate of the 1st heating device 9, and the hot air temperature of the 1st section 5 rises. The difference between the hot air temperature in the first zone 5 and the hot air temperature measured by the first contact temperature sensor 11 is the difference between the hot air temperature T in the second zone 6 and the measured temperature T of the second contact temperature sensor 16. Return to the set value ΔT.

  Conversely, when the hot air temperature T in the second section 6 and the measurement temperature T of the second contact type temperature sensor 16 are lowered, the hot air temperature T, the hot air temperature in the first section 5 and the measurement of the first contact type temperature sensor 11 are measured. The difference from the temperature deviates upward from the set value ΔT of the hot air temperature difference. Then, the 1st flow control valve 10 reduces the fuel supply flow rate of the 1st heating device 9, and the hot air temperature of the 1st section 5 falls. The difference between the hot air temperature in the first zone 5 and the measured temperature of the first contact type temperature sensor 11 is the difference between the hot air temperature T in the second zone 6 and the measured temperature T of the second contact type temperature sensor 16. Return to ΔT.

  That is, when the paper surface temperature of the printing paper a immediately after exiting from the outlet 3 deviates downward or upward from the set value t of the paper surface temperature, the hot air temperature T in the second area 6 and the downstream end area 6 increases or decreases, The hot air temperature in the first zone 5 and the upstream zone 5 also rises or falls. The hot air temperature in the first zone 5 and the upstream zone 5 and the hot air temperature in the second zone 6 and the downstream end zone 6 are controlled according to the paper surface temperature of the printing paper a just after exiting from the outlet 3. The printing paper a is unlikely to be insufficiently heated or excessively heated while passing through the first zone 5, the upstream zone 5 and the second zone 6, and the downstream end zone 6.

[Modification]
In the above embodiment, the drying chamber 1 is divided into the first zone 5 on the inlet 2 side and the second zone 6 on the outlet 3 side, and the second zone 6 on the outlet 3 side is the downstream end zone. The first zone 5 on the second side is the upstream zone, but is divided into a first zone on the inlet 2 side, a second zone in the middle, and a third zone on the outlet 3 side, and the third zone on the outlet 3 side. Is the downstream end zone and the intermediate second zone or the first zone on the inlet 2 side is the upstream zone.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic longitudinal side view of a printing paper drying apparatus provided with a temperature control device according to an embodiment of the present invention. The diagram which shows the hot air temperature and printing paper surface temperature in the drying apparatus.

Explanation of symbols

a belt-shaped printing paper 1 drying chamber 2 of drying apparatus 3 inlet of drying chamber 3 outlet 4 of drying chamber 4 printing paper passage 5 of drying chamber first zone upstream side of drying chamber 6 upstream zone 6 of the drying chamber outlet side 2 zone, downstream end zone 7 1st nozzle 8, 9 1st hot air supply path 8 1st blower 9 1st heating device 10 1st flow control valve 11 1st thermocouple, 1st contact type temperature sensor 12 2nd nozzle 13 , 14 Second hot air supply path 13 Second blower 14 Second heating device 15 Second flow control valve 16 Second thermocouple, second contact type temperature sensor 17 Non-contact type temperature sensor, infrared detection sensors 18, 19 Temperature control device 18 Temperature control device setting unit 19 Temperature control device control unit t Setting value ΔT of the paper surface temperature of the printing paper coming out from the outlet of the drying chamber Setting value T of the hot air temperature difference between the first zone and the second zone T Hot air temperature, measured temperature T + ΔT of the second contact type temperature sensor Hot air temperature in one area, temperature measured by the first contact temperature sensor

Claims (3)

The drying chamber forms a printing paper path from the inlet to the outlet, and divides the area between the inlet and the outlet into a plurality of areas, each of which has a nozzle and a hot air supply path for blowing hot air toward the printing paper path. In the drying device where the strip-shaped printing paper runs through the printing paper path and sequentially passes through each zone, and hot air hits each zone,
In the downstream end area on the outlet side of the drying chamber, a non-contact type temperature sensor that detects the paper surface temperature of the running printing paper is provided outside the outlet of the drying chamber, and the surface temperature detected by this non-contact type temperature sensor is the paper surface. A device for controlling the temperature of the hot air in the downstream end area is provided so that the temperature is set, and a contact-type temperature sensor for detecting the hot air temperature in the downstream end area is provided.
The upstream section upstream of the downstream end section of the drying chamber is provided with an upstream section contact temperature sensor that detects the hot air temperature in the upstream section, and the upstream section contact temperature sensor detects the upstream section contact temperature sensor. A device was installed to control the hot air temperature in the upstream area so that the difference between the hot air temperature and the hot air temperature in the downstream area detected by the contact-type temperature sensor in the downstream area becomes the set value of the hot air temperature difference. A temperature control device characterized by.   The drying chamber is characterized by dividing the space between the inlet and outlet into a first zone on the inlet side and a second zone on the outlet side, the second zone being the downstream end zone and the first zone being the upstream zone. The temperature control device according to claim 1. The hot air temperature in the downstream end area is higher than the set value of the paper surface temperature of the printing paper,
The temperature control device according to claim 1 or 2, wherein the hot air temperature in the upstream area is higher than the hot air temperature in the downstream area.

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