JP2920485B2 - Drying equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a drying apparatus for drying paper coated with an aqueous coating agent with hot air.

[0002]

2. Description of the Related Art Conventionally, a drying apparatus for drying a web made of a sheet of paper coated with a water-based coating agent with hot air, as shown in FIG. Direction), and a plurality of drying chambers 1, 1, 1 arranged in the same direction, and air circulation devices 2, 2, 2 provided for each drying chamber 1. Each drying chamber 1 is formed of a box-shaped casing 3 through which the sheet transport path R penetrates, and nozzles 4 and 4 are provided in the chamber 1a. Each nozzle 4 is provided with an ejection port for ejecting heated air toward the sheet conveying path R. Nozzle 4
May be provided only on one side facing the coating surface of the web W passing through the sheet conveyance path R, in addition to being provided on both the upper and lower sides of the sheet conveyance path R.

The air circulating device 2 is incorporated in the drying chamber 1 or provided outside the drying chamber 1 separately from the drying chamber 1. When the air circulation device 2 is provided separately from the drying chamber 1, the air circulation device 2 is joined to the drying chamber 1 by a duct. The air circulation device 2 includes a circulation fan 6 that blows air to the nozzles 4 and 4 via the supply path 5, a heater 7 that heats the air to be blown to a desired temperature, and a jet from the nozzles 4 and 4 into the drying chamber 1a. After the drying operation after contacting with the web W,
, A suction path 9 that guides fresh air to the circulation fan 6, and an exhaust path 10 that is branched from the reflux path 8 and extends. Each of the supply path 5, the intake path 9 and the exhaust path 10 is provided with a damper 11 for adjusting the amount of air. The exhaust passage 10 of each air circulation device 2 is joined to an exhaust fan 13 via a collective passage 12.

[0004] In order to increase the drying capacity in each drying chamber 1, it is only necessary to increase the wind speed, increase the temperature, and further reduce the relative humidity of the drying air ejected from the nozzles 4 and 4. The speed of the drying air is adjusted by adjusting the opening of the damper 11 provided in the supply path 5. The temperature of the drying air is adjusted by adjusting the temperature of the heater 7. Further, the relative humidity of the drying air is adjusted by adjusting the opening of the damper 11 provided in the intake passage 9 and the damper 11 provided in the exhaust passage 10.

[0005] When the coating agent is applied to the web W, the ear ends which are not coated with the coating agent are formed on the left and right sides of the web W running forward (in the direction of arrow F). The coating agent is prevented from flowing out of the section, and the guide rolls and the like provided between the coating device and the drying device are not stained with the coating agent. However, the web W is in the drying room 1,
Since the drying air is blown out under uniform conditions over the entire area in the left-right width direction while passing through 1, 1, the ear end where the coating agent is not applied may be overdried and curled. . The curl of the ear end causes a problem that the ear end is wrinkled.

To solve this problem, the relative humidity of the drying air ejected from the nozzles 4 and 4 of the drying chamber 1 located on the discharge side C is set to be high, so that the coated portion of the web W can be removed. There is a measure to suppress overdrying of the ear end without extremely reducing the drying ability. Then, in this measure, heat cylinders 15, 15 are provided on the outlet side of the drying chamber 1,
The web W is wound around the heat cylinders 15, 15 so that the final moisture control of the web W is performed. Setting the relative humidity of the drying air ejected from the nozzles 4 and 4 of the drying chamber 1 located on the carry-out side C to a high value depends on the type of the web and the coating conditions of the coating agent. In some cases, an effect of preventing fine wrinkles from being produced is exerted.

[0007]

By the way, each drying room 1
, The drying chambers 1 and 1 located on the loading side A and the middle B near the constant-rate drying area, and the drying chamber 1 located on the delivery side C and serving as the decreasing-rate drying area. Many. Therefore, in the drying chamber 1 located on the carry-out side C, the rise in the relative humidity of the drying air becomes very slow, and it takes a long time from the start of the drying operation to reach the optimum relative humidity. As a result, the conventional drying apparatus has a problem that the drying conditions are not stable for a long time from the start of the drying operation, and the yield is reduced.

[0008] The present onset Ming, in a short time from drying operation starts, it is possible to increase until the optimal humidity the relative humidity of the drying air in the unloading drying chamber, for drying in transportable delivery side drying chamber An object of the present invention is to provide a drying device capable of automatically adjusting the relative humidity of air.

[0009]

SUMMARY OF THE INVENTION The means for solving the problem] is e Bei a plurality of drying chambers arranged along the traveling direction of the sheet conveying path, and an air circulation device provided in each drying chamber, shea over preparative The exhaust path of the air circulation device provided in the loading-side drying chamber located on the loading side of the transport path is joined to the intake path of the air circulation device provided in the delivery-side drying chamber located on the loading side from the loading-side drying chamber. the drying device to use a drying operation after air entry side drying chamber as fresh air out side drying chamber, an exhaust passage of the air circulation device before Symbol unloading drying chamber, abandoned leads in addition to the drying chamber passage And a return path joined to the intake path of the air circulation device of the carry-in side drying chamber, and a flow rate adjusting damper for adjusting a distribution ratio to the discard path and the return path is provided at the branch point, and the carry-out side drying is performed. Measurement to measure the humidity of the supply path of the room air circulation device The provided a drying device, characterized in that the difference between the measured value and the set value of the measuring device is provided with adjustment operating member for operating the該風amount adjusting damper so as to zero.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a drying apparatus according to the present invention will be described based on an embodiment shown in FIG. The drying apparatus according to the present embodiment is provided with a plurality of drying chambers 1, 1, 1 arranged in the traveling direction (arrow F direction) of the sheet conveying path R, as in the conventional case, and for each drying chamber 1. Air circulation device 2,
2 and 2. The improvement of the drying apparatus in the present embodiment is that the exhaust passages 10 and 10 of the air circulation devices 2 and 2 provided in the loading-side drying chambers 1 and 1 located on the loading sides A and B serving as constant-rate drying areas are assembled. The collecting path 15 is joined to the intake path 9 of the air circulation device 2 provided in the unloading side drying chamber 1 located on the unloading side C serving as the rate-decreasing drying area. After that, the air is used as fresh air in the discharge-side drying chamber 1. The air after the drying operation is air that has been jetted from the nozzle 4 and has come into contact with the web W and is guided from the inside of the drying chamber 1a to the return path 8.

The exhaust path 9 of the air circulation device of the discharge-side drying chamber 1 located on the discharge side C is provided with an exhaust fan 16 in the middle thereof, and a disposal path 17 and a return path 1 communicating with other than the drying chamber.
8 and branching. At this branch point, an air volume adjusting damper 21 for adjusting the distribution ratio of air to the waste path 17 and the return path 18 is provided. The return passage 18 is connected to the intake passages 9, 9 of the air circulation devices 2, 2 of the carry-in side drying chambers 1, 1 located on the carry-in side A, B, and the intake fan 1.
By joining the fresh air introduction passage 20 through 9
Air having a desired relative humidity can be supplied to the intake passages 9 and 9.

The air volume adjusting damper 21 is automatically operated by an automatic adjusting device 23. The automatic adjustment device 23 includes a measuring device 24 that measures the humidity in the supply path 5 of the air circulation device 2 in the discharge-side drying chamber 1 located on the discharge side C.
And an adjustment operation tool 25 for operating the air volume adjustment damper 21 so that the difference between the measured value of the measuring device 24 and the set value becomes zero. The drying device can stabilize the humidity of the supply path 5 on the unloading side C to an optimum value by including the automatic adjusting device 23.

The air volume adjusting damper 21 is provided in each drying chamber 1.
Under the operating conditions in which the amount of dry moisture per hour is known in advance, program control or manual operation can be performed without using the automatic adjustment device 23.

The air circulating devices 2 and 2 provided in the drying chambers 1 and 1 on the loading sides A and B of the sheet transport path serving as a constant-rate drying area have a large amount of dry moisture per hour. Immediately after the start of the operation, the humidity of the air rapidly rises after the drying operation flowing through the return passages 8,8. The high-humidity air flowing through the return passages 8, 8 after the drying operation is discharged to the exhaust passages 10, 10 and the
The air is supplied to the intake path 9 of the air circulation device 2 provided in the discharge side drying chamber 1 located on the discharge side C via the discharge side 5. Therefore, the air circulation device 2 provided in the discharge side drying chamber 1 located on the discharge side C reaches the optimum relative humidity within a short time after the start of the drying operation. As a result, the drying apparatus in the present embodiment jets hot air for drying at the optimum humidity onto the web W from the nozzles 4, 4, 4 of all the drying chambers 1, 1, 1 within a short time after the start of the drying operation. It is possible to improve the yield.

The drying apparatus according to the present embodiment comprises a loading-side drying chamber 1, 1 located at the loading side A, B which is a constant-rate drying area.
The exhaust passages 10 and 10 of the air circulation devices 2 and 2 are connected to the intake passage 9 of the air circulation device 2 provided in the unloading side drying chamber 1 located on the unloading side C, which is a reduced-rate drying area. But,
Since the drying speed fluctuates depending on the physical properties of the coating agent and the amount of coating, etc., the constant-rate drying area is the loading-side drying chamber 1 located on the loading side A, and the constant-rate drying area is unloading on the delivery sides B and C. It may be the side drying room 1,1. In this case, although not shown, the exhaust path 10 of the air circulation device 2 provided in the carry-in side drying chamber 1 located on the carry-in side A, which is a constant-rate dry area, is connected to the carry-out side B, which serves as a reduced-rate dry area. What is necessary is just to join to the intake path 9 of the air circulation apparatus 2 and 2 provided in the discharge side drying chambers 1 and 1 located in C.

In short, in order to raise the relative humidity of the drying air in the discharge-side drying chamber located in the constant-rate drying area to the optimum humidity within a short time after the start of the drying operation, it is necessary to set the relative humidity in the constant-rate drying area. If the exhaust path of the air circulating device provided in the drying chamber of one or more chambers is joined to the intake path of the air circulating device provided in the drying chamber of one or more chambers located in the decreasing rate drying area. Good.

[0017]

As described in detail above, the drying apparatus according to the present invention
Has the following excellent effects.DryStart dry operation
Stabilize the drying conditions of the entire drying chamber in a short time.
Therefore, the yield can be improved.
DrySince the relative humidity of the drying air can be automatically adjusted,
Drying conditions can be constantly stabilized, and various drying conditions
In this case, the yield can be significantly improved.

[Brief description of the drawings]

FIG. 1 is an overall view schematically showing an embodiment of a drying apparatus according to the present invention.

FIG. 2 is an overall view schematically showing a conventional drying apparatus.

[Explanation of symbols]

 R ... Sheet conveying path 1 ... Drying chamber 2 ... Air circulation device 9 ... Intake path 5 ... Supply path 10 ... Exhaust path 21 ... Air volume adjustment damper 24 ... Measuring instrument 25 ... Adjustment operation tool

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁶ , DB name) B26B 21/04 B26B 13/10 B26B 21/00 B26B 25/22

Claims (1)

(57) [Claims] And 1. A plurality arrayed along the traveling direction of the sheet conveying path drying chamber and an air circulation device provided for each drying chamber <br/> Bei example, the loading-side sheet over preparative conveying path The exhaust path of the air circulation device provided in the carry-in side drying chamber is joined to the intake path of the air circulation device provided in the carry-out side drying chamber located on the carry-out side from the carry-in side drying chamber. After the drying operation, the drying device is designed to use the air as fresh air in the drying room on the discharge side .
And the exhaust path of the air circulation device in the discharge side drying chamber is
Discard path leading to other than the drying room and air in the drying room on the loading side.
Branch into a return path that joins the intake path of the circulation device,
Airflow control to adjust distribution rate for road and return path
A damper is provided at the branch point, and the air circulation
A measuring device for measuring the humidity of the supply path of the ring device is provided.
So that the difference between the measured value of the heater and the set value becomes zero.
It is characterized by the provision of an adjusting operation tool for operating the knot damper.
Drying equipment.