JP2553869B2 - Air supply / exhaust device for dryer - Google Patents

Description

Detailed Description of the Invention [Industrial applications]

TECHNICAL FIELD The present invention relates to an air supply / exhaust device for a drying chamber, and relates to an improvement for preventing fluctuations in indoor static pressure in the drying chamber.

[Prior art]

In the production of magnetic tapes and the like, there is a step of passing a material to be dried, which is obtained by applying or impregnating a coating liquid on a base material such as a sheet-shaped film, into a drying chamber to dry it. Generally, the drying room 1
As shown in FIG. 4, the outer wall 2 is formed of a heat insulating plate,
Nozzle 4, which is formed in 1a and injects a drying gas toward the material to be dried 7, on either the upper side or the lower side of the material to be dried passage 3.
There are some 4 ... arranged on the pitch as appropriate. Each nozzle 4 has a gas ejection port formed of a slit or a porous member, and is connected to a branch duct 5a or 5b of a drying gas supply duct 5. An exhaust duct 8 for discharging the reflux gas generated in the room 1a due to drying to the outside is connected to an appropriate position of the outer wall portion 2 of the drying room 1, and an inspection door 6 is provided as necessary. . A supply / exhaust device for supplying a drying gas to the thus configured drying chamber 1 and discharging a part of the reflux gas as an exhaust gas to the outside is configured as shown in FIG. A drying gas circulating device 10 for circulating a drying gas in the drying chamber 1 is connected to the drying chamber 1 and has a damper 13 in place.
A suction duct 15 provided with, a fresh gas supply duct 11 having a damper 14 in place, and a circulation fan 12 having the suction duct 15 connected to the suction port, and the drying gas supply connected to the discharge port of the circulation fan 12. It comprises a duct 5, a heat exchanger 16 and a high-performance filter 17 provided in the drying gas supply duct 5. The suction duct 15 is generally formed by branching the exhaust duct 8 (see FIG. 4) connected to the drying chamber 1. An exhaust device 20 for discharging a part of the reflux gas of the drying chamber 1 to the outside as an exhaust gas includes the exhaust duct 8, an exhaust fan 21 connecting the exhaust duct 8 to a suction port, and a damper 22 in a proper place. Exhaust duct for connection 23
And a gas concentration detector 24 for detecting the concentration of the solvent gas contained in the exhaust gas passing through the exhaust duct 8, and the opening degree of the damper 22 is automatically controlled based on the detection signal a of the gas concentration detector 24. It comprises an exhaust gas amount controller 25. Exhaust system
The reason why the opening degree of the damper 22 is automatically controlled in 20 is that it is necessary to ensure safety so that the concentration of the solvent gas in the drying chamber 1 does not always exceed the dangerous concentration. The adjustment of the drying gas circulation device 10 is performed by the exhaust device 20.
After manually adjusting the opening degree of the damper 14 of the fresh gas supply duct 11 based on the amount of exhaust gas of the nozzles 4, the nozzles 4, 4 housed in the drying chamber 1 by manually adjusting the damper 13 of the suction duct 15 ...
Adjust the gas ejection speed of.

[Problems to be Solved by the Invention]

By the way, the drying chamber 1 needs to be controlled so that the static pressure in the chamber 1a becomes a predetermined pressure. That is, in the case where the material to be dried 7 is coated or impregnated with a coating liquid containing a solvent having an explosion risk or toxicity, the solvent gas should not leak from the drying chamber 1 to the installation chamber in which the drying chamber 1 is installed. Moreover, it is necessary to control the negative pressure so that the static pressure in the drying chamber 1a is lower than the static pressure in the installation chamber. On the contrary, in the case of drying a photographic film or a magnetic tape which needs to maintain high cleanliness of gas circulating in the room 1a of the drying room 1, the air in the installation room with low cleanliness is the room of the drying room 1. It is necessary to control the positive pressure so that the static pressure in the drying chamber 1a is higher than the static pressure in the installation chamber so as not to enter the 1a. However, the conventional drying chamber supply / discharge device uses the damper 14 of the drying gas circulation device 10 based on the exhaust gas amount of the exhaust device 20.
After adjusting the amount of fresh gas by manually adjusting the opening of, the damper 13 of the suction duct 15 is manually adjusted and the drying chamber 1
Since the gas ejection speeds of the nozzles 4, 4 stored in the are adjusted, the following problems occur. (A) Since the opening of the damper 14 provided in the drying gas circulation device 10 is adjusted based on the exhaust gas amount of the exhaust device 20, the indoor static pressure of the drying chamber 1 is temporarily adjusted before adjusting the opening of the damper 14. This will cause a situation in which the predetermined negative pressure control or positive pressure control for the drying chamber 1 cannot be ensured. The above situation is remarkable especially in the drying chambers arranged in the initial drying area and the constant-rate drying area where the amount of exhaust gas discharged to the outside is 10% or more of the circulating gas amount circulating in the drying chamber. . (B) Suction duct provided in the drying gas circulation device 10
Since the damper 15 of 15 is adjusted last,
During the period from the adjustment of the opening degree of 14 to the adjustment of the opening degree of the damper 13, the gas ejection speed of the nozzles 4, 4, ... Temporarily fluctuates, resulting in fluctuation of the drying capacity. Fluctuations in the drying capacity cause fluctuations in the amount of exhaust gas, impairing the control stability of the entire air supply / exhaust system. In view of the above problems, an object of the present invention is to provide an air supply / exhaust device capable of supplying / exhausting air to / from the drying chamber without changing the indoor static pressure of the drying chamber and the gas ejection speed of the nozzle.

[Means for solving problems]

The gist of the present invention is to provide a drying chamber containing a nozzle for ejecting a drying gas and a circulation fan for sucking the reflux gas generated in the chamber of the drying chamber and mixing the reflux gas with fresh gas to supply the nozzle to the nozzle. A dryer gas supply / exhaust device comprising: a drying gas circulation device provided; and an exhaust device having an exhaust fan that discharges a part of the reflux gas to the outside as exhaust gas. A gas concentration detector for detecting the concentration of the solvent gas contained in the gas, a fresh gas amount controller for automatically controlling the amount of the fresh gas in response to a signal from the gas concentration detector, and the nozzle are supplied to the nozzle. The exhaust device includes a pressure detector that detects the pressure of the drying gas, and a fan rotation speed controller that automatically controls the rotation speed of the fan rotor of the circulation fan according to a signal from the pressure detector. A static pressure detection device for detecting the static pressure in the room is to have an exhaust gas amount controller for automatically controlling the amount of the exhaust gas in accordance with a signal the static pressure detecting device.

[Work]

If the solvent gas concentration in the reflux gas changes due to fluctuations in the speed of conveyance of the material to be dried passing through the drying chamber, the gas concentration detector detects the change in solvent gas concentration and sends a signal to the fresh gas amount controller. Emit. Upon receiving this signal, the fresh gas amount controller automatically controls the amount of fresh gas supplied to the drying gas circulation device and sets the solvent gas concentration in the drying gas supplied to the nozzle to the set gas concentration. When the static pressure in the drying chamber starts to change as the amount of fresh gas supplied to the drying gas circulation device changes, the static pressure detector provided in the exhaust device immediately detects this change, Sends a signal to the exhaust gas amount controller. The exhaust gas amount controller receiving this signal automatically controls the exhaust gas amount so that the exhaust gas amount corresponds to the fresh gas amount, and maintains the static pressure in the drying chamber at the set pressure.
A pressure detector provided in the drying gas circulation device immediately detects a sign of a change in the nozzle supply gas pressure caused by the fluctuation of the fresh gas, and issues a signal to the fan speed controller. Upon receiving this signal, the fan rotation speed controller automatically controls the fan rotor rotation speed of the circulation fan, sets the gas pressure supplied to the nozzle to the set pressure state, and maintains the drying capacity at a constant capacity.

[Explanation of the embodiment]

Hereinafter, an air supply / exhaust device for a dryer according to the present invention (hereinafter, referred to as “device of the present invention”) will be described based on an embodiment shown in the drawings. (First Embodiment) FIG. 1 shows a first embodiment of the device of the present invention.
The main improvement point of the present embodiment is that the drying gas circulation device 30 is provided with a gas concentration detector 31, a fresh gas amount controller 32, a pressure detector 33 and a fan speed controller 34, and the exhaust device 40 has a static pressure. That is, the detector 41 and the exhaust gas amount controller 42 are provided. Gas concentration detector provided in the drying gas circulation device 30
Reference numeral 31 is for detecting the concentration of the solvent gas contained in the reflux gas in the room 1a of the drying chamber 1, and sampling of the reflux gas is performed by the exhaust duct 8, the drying chamber 1a or the suction duct 15
It is done at. The gas concentration detector 31 outputs a signal b corresponding to the deviation value between the detected gas concentration value and the set gas concentration value.
Is output to the fresh gas amount controller 32. Fresh gas amount controller 32
The damper 14 further controls the opening of the damper 13 if necessary, and the circulation fan from the fresh gas supply duct 11 is used.
The amount of fresh gas supplied to 12 is automatically controlled based on the signal b, and the solvent gas concentration in the drying gas supplied to the nozzles 4, 4, ... Is set as a set value. Pressure detector 33
Are for detecting the pressure of the drying gas supplied to the nozzles 4, 4, ... And the pressure detection port 33a is opened at an appropriate place such as the branch duct 5a or the inside of the nozzle 4. Pressure detector 33
Outputs a signal c corresponding to the deviation value between the detected pressure value and the set pressure value to the fan rotation speed controller 34. The fan rotation speed controller 34 automatically controls the fan rotor rotation speed by controlling the rotation speed of the motor 35 for driving the circulation fan 12 based on the signal c by an appropriate control method such as an inverter control, and the nozzle 4 The drying gas pressure supplied to the nozzles 4, 4 ... Is set to a set pressure value, and the drying gas wind speed ejected from the nozzles 4, 4 ... Is set as the set value. The exhaust device 40
The static pressure detector 41 included in the drying chamber 1 detects the static pressure in the drying chamber 1a, and the pressure detecting port 41a is provided in the drying chamber 1a.
It is opened in place. The static pressure detector 41 outputs a signal d corresponding to the deviation value between the detected pressure value and the set pressure value to the exhaust gas amount controller 42. The exhaust gas amount controller 42 sends this signal d
Based on the above, the rotation speed of the motor 43 for driving the exhaust fan 21 is controlled by an appropriate control method such as an inverter control or, although not shown, the damper 22 provided in the connecting exhaust duct 23 (see FIG. 3). The amount of exhaust gas is automatically controlled by, for example, controlling the opening degree of), so that the static pressure in the drying chamber 1a becomes a set value. The drying chambers 1 ', 1'arranged in the latter half of the constant rate drying zone and in the decreasing rate drying zone have a small amount of dry solvent per hour. Therefore,
The change in the solvent gas concentration in the reflux gas in the drying chambers 1'and 1'is smaller than the change in the solvent gas concentration in the reflux gas in the drying chamber 1 arranged in the constant rate drying area. Therefore, the drying gas circulation device 50 arranged in the drying chambers 1 ', 1'is provided with one circulation fan 12 in each drying chamber 1', and an independent drying gas circulation is provided for each drying chamber 1 '. The circuit is provided with the paths A, A, and the circulation paths A, A are configured to be controlled by one gas concentration detector 31 and two fresh gas amount controllers 32, 32. A fresh gas supply device 51 for supplying fresh gas to the drying gas circulation devices 30 and 50 includes an outside air intake device 53 having a filter 52 and a supply fan 54 in which the outside air intake device 53 is connected to a suction port.
And a supply duct 55 connected to the outlet of the supply fan 53
And a damper 58 and a heat exchanger 56 provided in the supply duct 55.
And a high performance filter 57, a supply pressure detector 59 for detecting the pressure on the downstream side of the high performance filter 57, and a supply pressure detector
In response to the signal h of 59, the supply pressure controller 60 controls the discharge pressure of the supply fan 54 by controlling the rotation speed of the motor 61 of the supply fan 54. In the pretreatment chamber 65 arranged on the inlet side of the drying chamber 1, a fresh gas supply device 66 and an exhaust device 67 are connected so that the static pressure in the chamber 65a becomes a desired pressure. The fresh gas supply device 66 includes an outside air intake device 73 having a filter 72, a supply fan 74 connecting the outside air intake device 73 to a suction port, and a supply fan.
Supply duct 75 connected to the discharge port of 74 and supply duct 75
A damper 78 and a high-performance filter 77, a supply pressure detector 79 that detects the pressure on the downstream side of the high-performance filter 77, and a supply fan that receives a signal i from the supply pressure detector 79.
Supply fan 74 by controlling the number of rotations of motor 81 of 74
And a supply pressure controller 80 for controlling the discharge pressure of. The exhaust device 67 includes a connection duct 85 that connects the chamber 65a of the pretreatment chamber 65 and the collective exhaust duct 45, a damper 86 provided in the connection duct 85, and a static pressure detecting the static pressure inside the pretreatment chamber 65. It is composed of a pressure detector 87 and an exhaust gas amount controller 88 for controlling the opening degree of the damper 86. The static pressure detector 87 outputs a signal e corresponding to the deviation value between the detected pressure value and the set pressure value to the exhaust gas amount controller 88. The exhaust gas amount controller 88 sends this signal e
The amount of exhaust gas is automatically controlled based on the above, so that the static pressure in the pretreatment chamber 65a becomes a set value. A forced exhaust device 90 is arranged at the end of the collective exhaust duct 45. The forced exhaust device 90 is a forced exhaust fan 91.
And a pressure detector 92 for detecting the pressure in the vicinity of the end of the collective exhaust duct 45, and a collective exhaust gas amount controller 93. The pressure detector 92 outputs a signal g corresponding to the deviation value between the detected pressure value and the set pressure value to the collective exhaust gas amount controller 93. Based on this signal g, the collective exhaust gas amount controller 93 controls the rotation speed of the motor 94 that drives the forced exhaust fan 91 by an appropriate control method such as an inverter control or a damper 95.
The amount of exhaust gas is automatically controlled by controlling the opening degree of (not shown), and the pressure in the collective exhaust duct 45 is maintained at the set pressure. In the figure, 47 is a differential pressure indicator and 48 is a pressure gauge. (Second Embodiment) FIG. 2 shows a second embodiment of the device of the present invention.
The sheet coating / drying apparatus 100 is an unwinding chamber that houses the unwinding device 101.
102, a coating room 104 accommodating a coating machine 103 and the like, and a pretreatment device 1
A pre-treatment chamber 65 accommodating 05, a drying chamber 1, 1, 1, a post-treatment chamber 106 accommodating a cooling roll and the like, and a winding chamber 108 accommodating a winder 107. Unwinding room 102, coating room 104, pretreatment room 6
5. In each of the post-treatment chamber 106 and the winding chamber 108, a supply / discharge device 109 composed of the fresh gas supply device 66 and the exhaust device 67 is arranged for each set, and negative pressure control or positive pressure control is performed. Each of the drying chambers 1 is provided with a supply / exhaust device 110 composed of the drying gas circulation device 30 and the exhaust device 40 for each set, and negative pressure control or positive pressure control is performed. Since the sheet coating / drying apparatus 100 has the supply / discharge devices 109, 109, ... It can be changed as appropriate to optimize the gas flow to.

【The invention's effect】

As described in detail above, the device of the present invention has the following excellent effects. Since the solvent gas concentration of the reflux gas generated in the drying chamber is automatically controlled by the amount of fresh gas supplied to the drying gas circulation device, the concentration of solvent gas in the reflux gas is always stable at the set value, and the amount of fresh gas can be controlled. Since the static pressure fluctuation in the drying chamber that accompanies it is controlled by the amount of exhaust gas, the static pressure in the drying chamber is always stabilized at the set value. As a result, the device of the present invention can always ensure the predetermined negative pressure control or positive pressure control in the drying chamber even if the drying conditions change. Since the pressure detector and fan speed controller provided in the drying gas circulation device automatically control the pressure of the drying gas supplied to the nozzle to the set value, drying is always performed at the set wind speed from the nozzle. The working gas is ejected. As a result, the device of the present invention can stably maintain the drying capacity at a constant capacity, minimize the fluctuation of the amount of exhaust gas discharged from the exhaust device, and improve the stability of the entire control system of the air supply / exhaust device. Improve.

[Brief description of drawings]

1 and 2 show an embodiment of the device of the present invention. FIG. 1 is a schematic view showing the first embodiment, and FIG.
FIG. 4 is a schematic diagram showing an embodiment, FIG. 3 is a schematic diagram showing a supply / exhaust device of a conventional dryer, and FIGS. 4 (A) and 4 (B) are diagrams showing a conventional dryer. FIG. 4A is a front sectional view, and FIG. 1 ... Drying chamber, 4 ... Nozzle 12 ... Circulation fan, 21 ... Exhaust fan 30 (60) ... Drying gas circulation device 31 ... Gas concentration detector, 32 ... Fresh gas amount controller 33 ... … Pressure detector, 34… Fan speed controller 41… Static pressure detector, 42… Exhaust gas amount controller

Claims (2)

(57) [Claims] 1. A drying chamber containing a nozzle for ejecting a drying gas, and a circulation fan for sucking a reflux gas generated in the drying chamber and mixing a fresh gas with the reflux gas to supply the reflux gas to the nozzle. In the air supply / exhaust device of the dryer, the drying gas circulating device includes an exhaust device having an exhaust fan that discharges a part of the reflux gas to the outside as an exhaust gas. Gas concentration detector for detecting the concentration of solvent gas contained in, a fresh gas amount controller for automatically controlling the amount of the fresh gas according to a signal from the gas concentration detector, and a drying device supplied to the nozzle. A pressure detector for detecting the pressure of the working gas, and a fan rotation speed controller for automatically controlling the fan rotor rotation speed of the circulation fan according to the signal of the pressure detector, and the exhaust device is provided with Room A static pressure detection device for detecting the static pressure,
An exhaust gas amount controller for automatically controlling the amount of the exhaust gas according to a signal from the static pressure detector. 2. The air supply / exhaust device for a dryer according to claim 1, wherein the exhaust gas amount controller controls a fan rotor rotation speed of the exhaust fan.