JP3930801B2 - Continuous drying method and continuous drying apparatus - Google Patents

Description

【００４４】
比較例１
実施例１と同様の乾燥装置及び塗布乾燥条件で従来の操業条件で乾燥ボックスのガス濃度及び、被乾燥物の地合を両立する給排気条件を設定した結果を表２に示した。
【００４５】
【表２】

【００４６】
比較例１に比較して実施例１は排気量が少なく、溶媒処理装置にかかる負荷を減少することができた。また、実施例１における被乾燥物の地合、乾燥仕上は良好であったが、比較例１における被乾燥物の地合、乾燥仕上は若干のよどみ斑が見られた。
【００４７】
【発明の効果】
本発明の連続乾燥方法においては、最も溶媒蒸発量の多い乾燥ボックスに系外から気体を供給すると共に、該乾燥ボックスから、該気体の導入量よりも過剰な量の排気ガスを系外へ排気し、且つ該乾燥ボックスへ流入する気体の一部を連結するトンネルを通じ隣接する乾燥ボックスを通過させてから系外へ排出する連続乾燥方法であって、該乾燥ボックスから排出される排気ガスの量よりも少ないが、該乾燥ボックスの被乾燥物の排出口より流入する気体量と合計すれば、乾燥ボックスから排出される排気ガスの量よりも多い気体を供給し、且つ該供給した気体及び該乾燥物の排出口より流入する気体量の一部を連結するトンネルを通じ隣接する乾燥ボックスを通過させてから、系外に排出するので、給排気量を最も多く必要とする乾燥ボックスと、少量の給排気量しか必要としない乾燥ボックスの間における、給気量と排気量のバランスを容易に調整することができ、被乾燥物の仕上がりを良好なものとし、溶媒処理の経済性を確保することができる。
【００４８】
本発明の連続乾燥装置を用いると、前記連続乾燥方法を好適に実施することができる。
【図面の簡単な説明】
【図１】本発明の連続乾燥装置の一例を示す概略図である。
【符号の説明】
１ 連続乾燥装置
２ 気体導入装置
３ 排出装置
４ 温風ノズル
５ 乾燥ボックス
６ トンネル
７ 被乾燥物
８ 供給口
９ 排出口
１０ ブロワー
１１ ブロアー
１２ 伝熱装置
１３ 吸気ダンパー
１４ 送気ダンパー
１５ 循環ダンパー
１８ 排気ダンパー
１９ ブロワー[0001]
BACKGROUND OF THE INVENTION
The present invention relates to drying of a liquid film coated on a continuous web or the like, and more particularly to a continuous drying apparatus used for drying solvent coating and a method of using the same.
[0002]
[Prior art]
Conventionally, in a continuous dryer, a plurality of independent boxes have been used so that drying characteristics can be flexibly changed along a drying path. For example, US Pat. No. 5,060,396 (Patent Document 1) discloses a box-type cylinder dryer for removing a solvent from a moving support. In this dryer, the plurality of drying boxes are substantially separated and configured to operate at different temperatures and pressures. As described above, when separated into a plurality of drying boxes, the concentration of the solvent vapor is gradually reduced as the process proceeds, so that the residual solvent concentration of the final object to be dried can be kept low. However, Patent Document 1 does not describe a means for adjusting the concentration of gas discharged from the drying box and the supply / exhaust amount.
[0003]
In such a continuous dryer composed of a plurality of drying boxes, the connection between the drying box and the drying box is often connected by a tunnel having sufficient airtightness to block the air flow from the outside of the system. In particular, in the case of a continuous dryer that must prevent foreign matter that has entered from outside the system from adhering to the object to be dried, the connection between the drying box and the drying box should be connected by a tunnel with sufficient airtightness. Therefore, it is indispensable to block the air flow from outside the system.
[0004]
When drying a liquid film applied to a continuous web or the like using such a continuous dryer, conventionally, there is a problem that the liquid film applied to the web is disturbed and the formation of the coated film deteriorates. Could not prevent. In other words, in continuous dryers in which multiple drying boxes are connected by an airtight tunnel, the drying temperature and drying air speed of each drying box are set independently, so that a differential pressure is generated between the drying boxes. This differential pressure did not prevent the phenomenon of gas flow through the tunnel between adjacent dryer boxes. The flow of gas between the dryer boxes disturbs the liquid film applied to the web and causes a problem of deteriorating the formation of the coated film. In response to this problem, Japanese Patent Publication No. 2001-506178 (Patent Document 2) discloses that the deterioration of the coating condition is avoided by introducing a drying zone having no physical separation means. However, Patent Document 2 does not describe any means for adjusting the supply / exhaust amount focusing on economical solvent treatment.
[0005]
Further, when the solvent-based coated product is dried with a continuous dryer, the solvent gas discharged from each drying box is processed by the solvent processing apparatus and then discharged to the atmosphere from the viewpoint of environmental conservation. In general, the solvent processing apparatus has an upper limit of the gas flow rate that can be processed. Therefore, in order to process a certain amount of solvent, it is economical that the concentration of the solvent discharged from the drying box is as high as possible, and the environmental load is small. . On the other hand, in order to finish the material to be dried in a desired dry state (residual solvent), it is desirable that the solvent concentration of the gas exposed during drying is as low as possible. Moreover, in order to avoid explosion, the gas concentration in the drying box must be controlled to a concentration sufficiently lower than the lower limit concentration of the solvent.
[0006]
As explained above, in order to achieve both economic efficiency and environmental load reduction in the treatment of the solvent gas discharged from the continuous drying apparatus, and the drying finish and ensuring safety, the concentration of the solvent gas must be controlled with high accuracy. is required. Furthermore, in order to accurately control the concentration of the solvent gas, it is important to adjust the amount of air supplied from the outside of the system and the amount of exhaust to the outside of the system according to the amount of solvent evaporated in each drying box. Specifically, a large amount of solvent evaporates in the first half drying box of the continuous dryer, and almost no solvent evaporates in the latter drying box. It is necessary to appropriately distribute the supply / exhaust amount according to the difference between the drying boxes. However, in a continuous drying apparatus composed of a plurality of connected drying boxes, a pressure difference occurs between the above-mentioned drying boxes, so it is difficult to accurately adjust the supply / exhaust amount of each drying box. In particular, since the solvent hardly evaporates in the latter half of the dryer, the supply / exhaust amount required by the drying box is a very small value, so that accurate control is difficult.
[0007]
In particular, when the outside air is supplied by one general air supply device, the total amount of the outside air supplied to the entire continuous drying device is restricted, and thus it is difficult to appropriately distribute it to a plurality of drying boxes. That is, it is difficult to distribute the limited amount in a desired balance between a drying box that requires a large amount of air supply and a drying box that requires only a small amount.
[0008]
[Patent Document 1]
US Pat. No. 5,060,396
[Patent Document 2]
JP-T-2001-506178
[0009]
[Problems to be solved by the invention]
The present invention overcomes the drawbacks of the prior art, adjusts the supply / exhaust amount of each drying box of a continuous dryer with a simple configuration, and ensures the drying finish and the economics of solvent treatment, and It is an object to provide a drying method.
[0010]
[Means for Solving the Problems]
According to the present invention, the following inventions are provided.
[1] A plurality of drying boxes having at least means for introducing gas from outside the system, means for discharging gas inside the system to the outside of the system, and heat transfer means, a tunnel connecting these drying boxes, Using a continuous drying device having at least a supply port for introducing dried material into the continuous drying device and a discharge port for discharging the material to be dried, the material to be dried is introduced into the device from the supply port, and a plurality of drying boxes Gas is supplied from outside the system to the drying box with the largest amount of solvent evaporation, and the exhaust gas is in an excess amount from the amount of introduced gas. A continuous drying method in which the gas is discharged out of the system after passing through an adjacent drying box through a tunnel connecting a part of the gas flowing into the drying box. The amount of exhaust gas is less than the amount of exhaust gas discharged from the drying box, but the total amount of gas flowing in from the discharge port of the object to be dried of the drying box supplies more gas than the amount of exhaust gas discharged from the drying box, and A continuous drying method characterized by passing through a drying box adjacent to each other through a tunnel connecting a part of the gas supplied and the amount of gas flowing in from the discharge port of the dried product, and then discharging the system out of the system.
[2] The gas flowing in from the drying box adjacent to the drying box having the largest solvent evaporation amount includes a part of the gas supplied to the drying box having a discharge port for the object to be dried. The continuous drying method according to [1].
[3] The continuous drying method according to [1], wherein the velocity of the gas passing through the tunnel connecting the drying boxes is 3 m / s or less.
[4] The continuous drying method according to [1], wherein the exhaust gas is processed by a solvent combustion apparatus.
[5] A device for introducing gas from outside the system, a device for discharging gas inside the system to the outside of the system, a plurality of drying boxes having at least hot air nozzles, a tunnel connecting these drying boxes, In the continuous drying apparatus having at least a supply port for introducing the dried product into the continuous drying apparatus and a discharge port for discharging the material to be dried, the apparatus for introducing gas from outside the system includes at least a blower, a damper, and these A continuous drying apparatus having a duct connecting the two.
[6] The continuous drying apparatus according to [5] for a web having a coated surface, wherein the opening area on the web coating back surface side of the tunnel is larger than the opening area on the web coating surface side of the tunnel. A continuous drying device that is also wide.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be described below with reference to FIG.
First, the continuous drying apparatus of this invention is demonstrated. As shown in FIG. 1, the continuous drying device 1 used in the present invention includes at least a device 2 for introducing gas from outside the system, a device 3 for discharging gas inside the system to the outside, and a heat transfer device 12. It has at least a plurality of drying boxes 5, a tunnel 6 connecting these drying boxes 5, a supply port 8 for introducing the material to be dried 7 into the continuous drying device, and a discharge port 9 for discharging the material to be dried.
[0012]
The continuous drying apparatus 1 of the present invention has a plurality of drying boxes 5. Usually, the number of drying boxes is preferably 2 to 10, and more preferably 3 to 8. The apparatus 1 shown in FIG. 1 has five drying boxes 5a, 5b, 5c, 5d, and 5e, but the present invention is not limited to the five drying boxes 5. Although there is no restriction | limiting in the magnitude | size of the drying box 5, length 500-20000mm, width 500-5000mm, and height 500-6000mm are preferable, length 1500-1000mm, width 1000-3000mm, and height 1000-4000mm are more preferable. Although there is no restriction | limiting also in the material which comprises the drying box 5, Usually, structural carbon steel, stainless steel, and aluminum are used.
[0013]
In the continuous drying apparatus 1, a gas (usually air) is introduced from the outside of the apparatus 1 into each drying box 5 by the blower 10 in the apparatus 1, and a gas is introduced from outside the system (hereinafter also simply referred to as a gas introduction apparatus). ) Gas is supplied to each drying box 5 through 2.
[0014]
The gas introduction device 2 preferably has at least a blower, a damper, and a duct connecting them, and at least a blower 11, a heat transfer device 12, an intake damper 13, an air supply damper 14, and a duct connecting them. More preferably, 21 is included. Specifically, the gas sent from the blower 10 is introduced into the heat transfer device 12 through the duct 21 after the intake air amount is adjusted by the intake damper 13, and the gas is heated by the heat transfer device 12, and then the gas Is more preferably sent to the drying box 5 through the blower 11 and the damper 14.
[0015]
If the intake damper 13 is provided, the gas passage resistance can be changed by adjusting the opening degree of the intake damper 13, so that the amount of gas supplied from the blower 10 can be adjusted appropriately.
[0016]
If the heat transfer device 12 is provided in a device for introducing gas from outside the system, that is, between the intake damper 13 and the drying box 5, the temperature of the gas supplied from the blower 10 can be adjusted. The drying state of the object to be dried can be controlled by changing the amount of heat transferred from the warm air nozzle 4 to the object to be dried.
[0017]
When the air supply damper 14 is provided, it is possible to change the gas flow rate to the hot air nozzle 4 by changing the flow resistance of the gas supplied from the blower 11, and from the gas to the object to be dried. The amount of heat given by convection heat transfer and the mass transfer coefficient for dissipating components evaporated from the object to be dried can be changed to control the drying state of the object to be dried. Further, by changing the gas flow rate, when the coating film of the object to be dried may be disturbed by the gas, it can be an adjusting means for avoiding the phenomenon.
[0018]
The gas introducing device 2 of the present invention has a blower 11, a heat transfer device 12, an intake damper 13, an air supply damper 14, and a duct 21 connecting them, as shown in FIG. More preferably, the drying box 5 has a circulation duct 16 that connects the duct 12 between the intake damper 13 and the heat transfer device 12, and the circulation damper 15 is provided in the middle of the circulation duct 16. When configured in this way, the damper 15 can adjust the flow rate of the gas passing through the duct 16, so that the amount of gas circulating to the heat transfer device 12 can be changed again via the duct 16. it can. As described above, the flow rate supplied to the hot air nozzle 4 is substantially adjusted by the capabilities of the air supply damper 14 and the blow 11, but the circulation flow rate and the blower 10 are maintained while maintaining the same flow rate. It is possible to adjust the amount of gas taken in from the intake air and supplied from the intake damper 13. Thereby, it is possible to adjust the concentration of the evaporation solvent in the drying box 5.
[0019]
In the continuous drying device 1, it is preferable that each drying box 5 has the gas introduction device 2 at the top and bottom thereof so that the gas can be introduced into the drying box 5 from above and below. It is preferable that at least the drying boxes 5a, 5b, and 5c having a high solvent concentration have the gas introduction device 2 above and below them. If comprised in this way, the gas introduce | transduced from the gas introduction apparatus 2 will be supplied to the upper and lower surfaces of to-be-dried material from each warm air nozzle 4, and the calorie | heat amount given to to-be-dried material will be large compared with one side. Efficient drying. Furthermore, when the object to be dried has a coating film on a long web, depending on the properties of the coating film, in order to obtain the desired drying quality, warm air is applied to the surface on which the coating film is provided. In some cases, it may be supplied, or in some cases, the desired dry quality cannot be obtained. In such a case, if the gas introducing devices are provided above and below, the drying conditions required as appropriate can be set by the same drying device, and the versatility of the device is improved.
[0020]
A device 3 that discharges gas in the system to the outside of the system (hereinafter also simply referred to as a discharge device) 3 is usually performed by sucking exhaust gas by a blower 19 through an exhaust damper 18. One blower 19 is usually sufficient as the entire continuous drying apparatus 1 and is connected to the blower 19 via the exhaust damper 18 for each drying box 5.
[0021]
Although there is no restriction | limiting in the system of the hot air nozzle 4, Usually, a jet nozzle system is preferable.
[0022]
Each drying box 5 is preferably provided with means for holding the object to be dried and transporting it smoothly. In particular, when the object to be dried 7 is long, it is preferable to provide means for holding the object to be dried and transporting it smoothly so that the object to be dried 7 does not hang down. The means includes a roll support type and a floating type. As shown in FIG. 1, the roll support type is a means for providing a rotating roll 20 and supporting and transporting an object 7 to be dried thereon. The floating type is a means for supporting and transporting the object 7 to be dried by the gas supplied from the lower surface side alone or from the hot air nozzle on the upper surface side. In the present invention, means in which these are combined is also preferable. However, the present invention is not limited to these.
[0023]
As shown in FIG. 1, the gas introducing device 2 of the present invention is provided with a blower 10, a blower 11, and a blower 19 in order to supply, discharge, and circulate gas to the drying box 5. In adjusting these intake / exhaust capacities, it is desirable to have a mechanism capable of controlling the shaft rotational speed. The method for controlling the shaft rotational speed is not particularly limited, but a configuration in which the motor is inverter-controlled is desirable. By doing so, it becomes possible to adjust the supply / exhaust amount in combination with the setting of each damper.
[0024]
In the continuous drying apparatus 1 of the present invention, the drying boxes 5 are connected to each other through a tunnel 6, and the material to be dried 7 moves from the drying box 5 to the drying box 5 through the tunnel 6. The tunnel 6 preferably has sufficient airtightness in order to block the airflow from the outside of the system and efficiently dry the material 7 to be dried.
[0025]
The continuous drying device 1 of the present invention has a supply port 8 for introducing the material 7 to be dried into the continuous drying device 1 and a discharge port 9 for discharging the material to be dried. As shown in FIG. 1, the material to be dried 7 is continuously supplied into the apparatus 1 from the supply port 8, dried, and then discharged from the discharge port 9.
[0026]
Although there is no restriction | limiting in the magnitude | size of the supply port 8, and it determines suitably according to the magnitude | size of a to-be-dried object, Usually, it is 5 to 500 mm in length and 500 to 5000 mm in width. The supply port 8 needs to have a sufficient opening so that the material to be dried 7 can be introduced into the drying device without coming into contact with the members of the drying box 5, but the solvent vapor in the drying box is exposed to the outside air. In order not to leak, it is desirable that the opening of the supply port 8 is narrow. Among these restrictions, in particular, when the object to be dried 7 is long, the opening of the supply port 8 is appropriately set in consideration of the flutter caused by the conveyance.
[0027]
Although there is no restriction | limiting in the magnitude | size of the discharge port 9, and it determines suitably according to the magnitude | size of a to-be-dried object, Usually, it is 5 to 500 mm in length and 500 to 5000 mm in width. The discharge port 9 needs to have a sufficient opening so that the material to be dried 7 can be discharged from the drying device without coming into contact with the members of the drying box 5, but the solvent vapor in the drying box is discharged to the outside air. In order to prevent leakage, it is desirable that the opening of the discharge port 9 is narrow. Among these restrictions, particularly when the object to be dried 7 is long, the opening of the discharge port 9 is appropriately set in consideration of the fluttering caused by the conveyance of the object to be dried.
[0028]
The continuous drying apparatus of the present invention is suitably used for drying a liquid film coated on a continuous web or the like, particularly for drying a solvent coating and for drying a heat-sensitive recording material. However, the present invention is not limited to this.
[0029]
When drying a web or the like having a coating surface using the continuous drying apparatus 1 of the present invention, the opening area on the web coating back surface side of the tunnel constituting the apparatus 1 is the opening area on the web coating surface side of the tunnel. It is preferable that the width is wider. There may be a pressure difference between the drying boxes connected by the tunnel, in which case the gas flows through the connected tunnels, and the liquid film provided on the web surface when the gas flow rate increases. May affect the dry quality, especially the texture and spots. In such a case, by configuring the tunnel to be wider than the opening area on the web coating surface side of the tunnel, even if the gas flow rate flowing through the tunnel is the same, the flow rate flowing to the liquid film side decreases. Therefore, the influence on formation, spots, etc. can be reduced.
[0030]
In addition, the web which has a coating surface in this invention means what provided the liquid film on base materials, such as a film and paper. The continuous drying apparatus 1 of the present invention is suitable for a web having a liquid film thickness of about 1 μm to 500 μm. In particular, it is suitable for drying a heat-sensitive recording material, a heat-sensitive recording material capable of repetitive recording, and a photosensitive material.
[0031]
Next, the continuous drying method of the present invention will be described. In the following description, the case of the continuous drying apparatus 1 of the aspect shown in FIG. 1 provided with five drying boxes will be described. However, this invention is not limited to the continuous drying apparatus 1 of the aspect shown in FIG.
[0032]
In the method of the present invention, the above-described continuous drying apparatus 1 is preferably used. That is, in the method of the present invention, a plurality of drying boxes having at least a means for introducing gas from outside the system, a means for discharging gas inside the system to the outside of the system, and a heat transfer means are connected to these drying boxes. A continuous drying apparatus having at least a tunnel to be dried, a supply port for introducing the material to be dried into the continuous drying device, and a discharge port for discharging the material to be dried is used.
[0033]
In the present invention, the material to be dried is introduced into the apparatus from the supply port, and passes through a plurality of drying boxes and then discharged from the discharge port. While supplying the gas, the exhaust box exhausts an amount of exhaust gas that is excessive from the amount of the gas introduced into the system (hereinafter also simply referred to as excess exhaust gas amount) and flows into the dry box. After passing through the adjacent drying box through a tunnel connecting part of the gas, it is discharged out of the system. In the present invention, the drying box 5b is usually the drying box with the largest amount of solvent evaporation. The gas introduction device 2 is operated to supply the gas from outside the device 1 to the drying box 5b. At the same time, the gas discharge device is operated to exhaust a quantity of exhaust gas that exceeds the amount of gas introduced into the drying box 5b to the outside of the system. Specifically, the excess exhaust gas amount is preferably 10 to 100% excess, more preferably 10 to 50% excess, and more preferably 10 to 30% excess with respect to the introduced gas amount. Further preferred. At the same time, the gas passes through the adjacent drying box 5b through the tunnel 6b connecting a part of the gas flowing into the drying box 5c, and is then discharged out of the system.
However, the present invention does not limit the drying box with the largest solvent evaporation amount to the drying box 5b, and the drying box 5b has the largest solvent evaporation amount in the case of the continuous drying apparatus of the embodiment shown in FIG. Thus, the drying box with the largest amount of solvent evaporation can vary depending on the number of drying boxes, the conveyance speed of the object to be dried, and the like.
[0034]
In the present invention, after passing through the adjacent drying box 5b and then discharging out of the system, specifically, the gas introduced into the drying boxes 5c, 5d, and 5e, and a part of the solvent gas generated there are used. It is introduced into the drying box 5b through the connecting tunnel 6b and discharged. 5-50% of the amount of gas discharged | emitted from the drying box 5b is desirable, as for the quantity which distribute | circulates the tunnel 6b to connect, it is more preferable that it is 5-20%, and 5-10% is further more preferable. When the object to be dried is dried in this way, the air supply amount between the drying box 5b that requires the largest amount of air supply / exhaust and the drying boxes 5c, 5d, and 5e that require only a small amount of air supply / exhaust. And the displacement of the exhaust gas can be adjusted to prevent a differential pressure from being generated between the drying boxes 5. As a result, the liquid film applied to the web is not disturbed, and the formation of the coated film is not deteriorated, so that the finish of the material to be dried is improved and the economics of the solvent treatment is ensured. be able to.
[0035]
In the present invention, the amount of gas supplied from outside the system to the drying box with the largest solvent evaporation amount is smaller than the amount of exhaust gas discharged from the drying box (excess exhaust gas amount). It is preferable to supply a larger amount of gas than the amount of exhaust gas discharged from the drying box if the total amount of gas flowing in from the discharge port of the dried material is added. Specifically, the amount of gas supplied from the outside of the device 1 by operating the gas introduction device 2 to the drying box 5b is smaller than the excess exhaust gas amount, but the amount covered by the drying boxes 5c, 5d, and 5e. If the total amount of gas flowing in from the dry matter discharge port 9 is The amount of gas that is larger than the amount of exhaust gas discharged from the drying box. More preferably, 5 to 10% less gas is supplied than the amount of exhaust gas discharged from the drying box. That is, in order to prevent the exhaust gas from flowing out of the drying apparatus 1 to the system, particularly to the work site, the supply air amount and the exhaust gas in consideration of the amount of gas flowing into the drying apparatus 1 from the discharge port 9 of the object to be dried It is preferable to balance the amounts. In this way, air supply / exhaust between the drying box 5b that requires the largest amount of air supply and exhaust (amount of air supply / exhaust) and the drying boxes 5c, 5d, and 5e that require only a small amount of air supply / exhaust. The amount balance can be more easily adjusted to reduce the differential pressure between the drying boxes. As a result, the finish of the material to be dried 7 can be made better, and the economics of the solvent treatment can be further ensured.
[0036]
In the present invention, the gas flowing from the drying box 5c adjacent to the drying box 5b having the largest amount of solvent evaporation includes a part of the gas supplied to the drying box 5e having the discharge port 9 for the object 7 to be dried. Is preferred. Specifically, it is connected to the drying box 5b. Of the exhaust damper 18 The damper is opened and at least one of the exhaust dampers 18 connected to the drying boxes 5c, 5d, 5e is adjusted in the closing direction. Further, the intake damper 13 connected to the drying box 5b is closed, and at least one of the intake dampers 13 connected to the drying boxes 5c, 5d, and 5e is adjusted in the opening direction.
[0037]
In this way, it is possible to improve the balance of the supply / exhaust amount in consideration of the amount of gas flowing in from the discharge port 9 of the object to be dried, the drying box 5b that requires the most supply / exhaust amount, and a small amount Since the balance of the supply / exhaust amount between the drying boxes 5c and 5d, 5e, which only requires the supply / exhaust amount, can be more easily adjusted, and the differential pressure between the drying boxes can be further reduced, the object to be dried The finish of 7 is further improved, and the economics of solvent treatment can be further ensured.
[0038]
In the present invention, the velocity of the gas passing through the tunnel connecting the drying box 5 is preferably 3 m / s or less, and more preferably 1 m / s or less. When continuous drying is performed under such conditions, the finish of the coating film can be improved, and the economics of solvent treatment and the reduction of environmental burden can be achieved.
[0039]
In the present invention, there is no limitation on the method for introducing the material to be dried 7 into the continuous drying apparatus 1 and the method for discharging it to the outside of the system. However, as shown in FIG. In this case, it is preferable that the material to be dried 7 is introduced into the apparatus 1 while being rewound and discharged while being wound in a roll shape.
[0040]
【Example】
Examples of the present invention will be described below. However, the present invention is not limited to this.
[0041]
Example 1
85 g / m of a coating liquid (solvent ratio MEK / toluene = 50% / 50%) mainly composed of a resin having a solid content of 20% on a 175 μm PET film having a substrate width of 1070 mm ² The coating was applied, introduced into the continuous dryer of the embodiment shown in FIG. 1, and dried. The temperature of the drying box was all 90 ° C.
[0042]
Table 1 shows the results of setting the supply / exhaust conditions that achieve both the gas concentration in the drying box and the formation of the object to be dried from the drying conditions in the object to be dried and the drying box.
[0043]
[Table 1]

[0044]
Comparative Example 1
Table 2 shows the results of setting the supply / exhaust conditions that achieve both the gas concentration of the drying box and the formation of the object to be dried under the conventional operating conditions using the same drying apparatus and coating drying conditions as in Example 1.
[0045]
[Table 2]

[0046]
Compared to Comparative Example 1, Example 1 had a small displacement and was able to reduce the load on the solvent treatment apparatus. Moreover, although the formation and dry finish of the to-be-dried material in Example 1 were favorable, the stagnation spots of the to-be-dried material in Comparative Example 1 were found to be slightly stagnation.
[0047]
【The invention's effect】
In the continuous drying method of the present invention, Gas is supplied from the outside of the system to the drying box with the largest solvent evaporation amount, and an excess amount of exhaust gas is exhausted from the drying box to the outside of the system and flows into the drying box. A continuous drying method in which a gas is passed through an adjacent drying box through a tunnel connecting a part of the gas and then discharged out of the system, and the amount is less than the amount of exhaust gas discharged from the drying box. If the total amount of gas flowing in from the discharge port of the material to be dried is supplied, a gas larger than the amount of exhaust gas discharged from the drying box is supplied, and the supplied gas and the gas flowing in from the discharge port of the dry material Pass through the adjacent drying box through a tunnel connecting a part of the volume, and then discharge it outside the system. Therefore, it is possible to easily adjust the balance between the air supply amount and the exhaust amount between the drying box that requires the largest amount of supply and exhaust air and the drying box that requires only a small amount of air supply and exhaust. It is possible to improve the finish of the solvent and to ensure the economics of the solvent treatment.
[0048]
If the continuous drying apparatus of this invention is used, the said continuous drying method can be implemented suitably.
[Brief description of the drawings]
FIG. 1 is a schematic view showing an example of a continuous drying apparatus of the present invention.
[Explanation of symbols]
1 Continuous dryer
2 Gas introduction device
3 Discharge device
4 Hot air nozzle
5 Drying box
6 Tunnel
7 To be dried
8 Supply port
9 Discharge port
10 Blower
11 Blower
12 Heat transfer device
13 Intake damper
14 Air damper
15 Circulation damper
18 Exhaust damper
19 Blower

Claims (6)

A plurality of drying boxes having at least a means for introducing gas from outside the system, a means for discharging gas inside the system to the outside of the system, and a heat transfer means, a tunnel connecting these drying boxes, and an object to be dried Using a continuous drying device having at least a supply port for introducing into the continuous drying device and a discharge port for discharging the material to be dried, the material to be dried is introduced into the device from the supply port and passed through a plurality of drying boxes. Then, gas is supplied from outside the system to the drying box with the largest amount of solvent evaporation, and an excessive amount of exhaust gas is introduced from the drying box to the outside of the system. A continuous drying method in which the gas is discharged to the outside after passing through an adjacent drying box through a tunnel connecting a part of the gas flowing into the drying box .
A gas that is smaller than the amount of exhaust gas discharged from the drying box, but is larger than the amount of exhaust gas discharged from the drying box if the total amount of gas flowing in from the discharge port of the object to be dried of the drying box And passing through an adjacent drying box through a tunnel connecting a part of the gas supplied and the gas flowing in from the discharge port of the dried product, and then discharging out of the system . Continuous drying method. The gas flowing in from the drying box adjacent to the drying box having the largest solvent evaporation amount includes a part of the gas supplied to the drying box having a discharge port for the object to be dried. The continuous drying method described. The continuous drying method according to claim 1, wherein the velocity of the gas passing through the tunnel connecting the drying boxes is 3 m / s or less . The continuous drying method according to claim 1, wherein the exhaust gas is processed by a solvent combustion apparatus . A device for introducing gas from outside the system, a device for discharging gas inside the system to the outside of the system, a plurality of drying boxes having at least a hot air nozzle, a tunnel connecting these drying boxes, and an object to be dried In the continuous drying apparatus having at least a supply port for introducing into the continuous drying apparatus and a discharge port for discharging an object to be dried, the apparatus for introducing gas from outside the system includes at least a blower, a damper, and a duct connecting them. A continuous drying apparatus comprising: The continuous drying device according to claim 5 for a web having a coated surface, wherein an opening area on the web coating back surface side of the tunnel is wider than an opening area on the web coating surface side of the tunnel. Features a continuous drying device.

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