JPS62138675A - Suction drying method utilizing heat transfer by radiation - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION "Industrial Application Field" The present invention is directed to the use of far-infrared radiant heaters, infrared lamps, The present invention relates to a suction drying method using radiant heat transfer using a radiant heat transfer plate such as a microwave.

"Prior Art" Conventionally, a cheese microwave drying method is known in which cheese (twill yarn) is vacuum-dried in a vacuum chamber using microwaves in such a radiant heat transfer plate. In addition, the present applicant has already proposed a pressure difference type dehydrator in Utility Application No. 1983-000856, the gist of which is that processed materials such as textiles (fabric) are processed through a nonwoven fabric roll in a chamber within a substantially vacuum region.
Furthermore, it is known that infrared radiant heaters for radiant heat transfer plates and infrared lamps are used as heat sources for drying various things.

"Problems to be Solved by the Invention" By the way, efficient drying is achieved by directly irradiating the electromagnetic waves emitted from these radiant heat exchanger plates onto the processed material. However, when the water vapor evaporated from the processed material is diffused around the processed material and a water vapor film is generated, a large proportion of electromagnetic waves, such as far infrared rays (radiant heat transfer), are absorbed by the vapor film, causing an effect on the processed material. Efficient drying is not possible due to a decrease in the amount of radiant heat transfer. In addition, the relative humidity within the water vapor film is extremely high, especially near the surface of the material to be treated, which approaches 100%, making it impossible to obtain a gradient of water vapor partial pressure and reducing the evaporation rate, resulting in efficient drying as described above. There were problems such as the inability to

"Means for Solving the Problems" In view of the above, the present invention actively reduces the water vapor film generated near the surface of the object by the water vapor generated from the surface of the object during the heating process with the radiant heat transfer plate. The gist is that in the process of the processed material passing at a predetermined speed through a nearly closed drying chamber equipped with a radiant heat transfer plate,
When the water vapor evaporated from the processed material is diffused around the processed material and a water vapor film is generated, this water vapor film is actively removed to the outside of the drying chamber through means such as exhaust or blowing. If a water vapor film is generated in the process of moving the material forward, it is removed in the same manner as described above, etc., and the generation and removal of the water vapor film is repeated as appropriate in the process of moving the material forward. Or, depending on the case, it is a suction drying method using radiant heat transfer in which the above-mentioned removal is performed only once.

"Function" Next, to explain the present invention in detail, in the process of the processed material passing at a predetermined speed through a substantially closed type drying chamber provided with a radiant heat transfer plate, radiation is radiated onto the surface of the processed material. The heat transfer plate is directly irradiated with electromagnetic waves such as radiant heat transfer, and as it is heated, water vapor evaporates and diffuses from the surface and is sequentially dried.This evaporation and diffusion of water vapor causes the transfer of the processed material. As time passes, it accumulates and eventually forms a water vapor film. When water vapor is generated in this manner, most of the amount of radiant heat transfer is absorbed by this vapor film, and the amount of radiant heat transfer acting on the object to be treated is reduced. Therefore, in order to avoid such a situation, this water vapor film is actively removed to the outside of the drying chamber through means such as exhaust or blowing.

As a result, the area around the object to be treated is returned to its initial state, and the evaporation and diffusion of water vapor from the surface of the object is promoted.

Then, when a water vapor film is generated in the same manner as described above, it is actively removed through the above-mentioned means.Such operations are repeated in the drying chamber, and in some cases, the material to be treated can be dried in just one operation. processing.

``Embodiment'' The drawing schematically shows an embodiment of the present invention. First, to explain the first invention in detail, a substantially closed drying chamber 1 includes a far-infrared radiation heater, an infrared lamp, and a microwave. Radiant heat transfer plates 2 and 3 that radiate heat, etc. are arranged, and the processed material 4 is passed between the radiant heat transfer plates 2 and 3 at a predetermined speed, and the radiant heat transfer plates 2 and 3 emit radiation onto the surface of the material 4. When heated by direct irradiation with radiation heat transfer 5, the surface of the processed material 4 is directly heated, and the contained moisture becomes water vapor 6 and is evaporated and diffused from the surface, resulting in the state shown in Fig. 2 (a). Become. This water vapor 6
In this case, since the relative humidity in the drying chamber 1 is low, most of the drying material is actively evaporated and diffused and does not remain around the processed material 4. However, as the water vapor 6 diffuses and the relative humidity inside the drying chamber 1 increases, the evaporation and diffusion decreases, and as time passes, it gradually accumulates.
)~(・→), and finally the relative humidity rises to the maximum as shown in the same figure (=) and a water vapor film 7 is generated.When the water vapor film 7 is generated in this way, this water vapor film In step 7, most of the heat from the radiant heat transfer 5 is absorbed and the amount of radiant heat transferred acting on the processed material 4 is reduced, so this water vapor film 7 is actively removed to the outside of the drying chamber 1 via the exhaust means 8. , the surroundings of the object to be processed 4 are returned to the initial state as shown in the same figure (E). By doing so, the relative humidity on the surface and surroundings of the object to be processed 4 decreases, the evaporation rate increases, and the latent heat of evaporation increases. y) A temperature gradient is formed between the processed material 4 whose surface temperature has decreased and the radiant heat transfer plates 2 and 3, and the propagation efficiency of the amount of heat is improved, and the heat is actively evaporated and diffused again. state. After that, as in the case described above, a water vapor film 7 is generated as shown in (-') via (-') in the same figure, so this water vapor film 7 is similarly removed via the exhaust means 8. The state shown in FIG. 4(E') is reached, in which the processed material 4 is actively removed and the surroundings of the processed material 4 are returned to the initial state.

Such operations are repeated one after another, and in some cases, the processed material 4 is dried by only one operation, and then introduced from the drying chamber 1 to the outside. As the exhaust means 8, exhaust nozzles 8a are used on both sides of the processed material 4, and the drying chamber 1 is connected to the exhaust nozzles 8a.
The ideal structure is to connect the hose 8b led outside.

Next, to explain the second invention in detail, a substantially closed type drying chamber 1
All radiant heat exchanger plates 2 and 3 are arranged inside the radiant heat exchanger plate 2.
When the object 4 to be processed is passed through the object 4 at a predetermined speed during 3, and the surface of the object 4 is directly irradiated with the radiant heat 5 radiated from the radiant heat transfer plate 2 to heat it, the surface of the object 4 to be processed is directly heated. The state shown in FIG. 6 (D) is reached in which the contained moisture becomes water vapor 6 and is evaporated and diffused from the surface. In this case, since the relative humidity in the drying chamber 1 is low, most of this water vapor 6 actively evaporates and diffuses and does not stay around the object 4 to be treated. However, as water vapor 6 diffuses and the relative humidity inside the drying chamber 1 increases, evaporation and diffusion decrease, and as time passes, the water vapor gradually accumulates.
~(nu), and finally, as shown in (l) of the same figure, the relative humidity rises to the maximum and water vapor @7 is generated.

When the water vapor film 7 is generated in this way, most of the heat of the radiant heat transfer 5 is absorbed by this water vapor film 7, and the processed material 4
Since the amount of radiant heat transfer acting on the water vapor film 7 decreases,
is diffused into the drying chamber 1 through the blowing means 10, and at the same time, the water vapor 6 diffused through the exhaust means 11 provided in the drying chamber 1 is actively pumped out of the drying chamber 1 together with the air inside the drying chamber 1. After removal, the periphery of the object 4 to be treated is returned to its initial state as shown in FIG. 4(E). Things to be processed from words like that 4
The surface and surrounding relative humidity of the processed material 4 and the radiant heat exchanger plate 2 are reduced, the evaporation rate increases, and the surface temperature of the processed material 4 and the radiant heat exchanger plate 2 is reduced due to the air blowing by the blowing means 10 and the latent heat of evaporation.
A temperature gradient is formed between the temperature and the temperature of 3°C, the efficiency of heat transfer improves, and the state shown in the figure (h') is reached where the heat is actively evaporated and diffused again. After that, the same figure (υ′) as in the previous case
Since a water vapor film 7 is generated as shown in (R') through ~(NU'), this water vapor film 7 is similarly actively removed through diffusion by the blowing means 10 and suction by the exhaust means 11. As a result, the surface temperature of the object 4 to be treated is lowered and the surrounding area is returned to the initial state as shown in FIG. Such operations are repeated one after another, and in some cases, the processed material 4 is dried by only one operation and then guided to the outside from the drying chamber 1. The blowing means 10 and the exhaust means 11 are as follows:
As in the example shown in FIG. 3, the blow-off nozzle 10a connected to the hose 10b is used as the blow-off means 10, and the exhaust nozzle lla installed opposite to this blow-off nozzle 10a is used as the exhaust means 11, or as shown in FIGS. As in the example, it is preferable that the blow-off nozzle 10a connected to the hose 10b is used as the blow-off means 10 (same as in FIG. 3), and the exhaust nozzle 11b provided on the outer wall of the drying chamber 1 is used as the exhaust means 11. Furthermore, as in the example shown in FIG.
It is thought that if this is provided, wobbling of the processed material 4 will be eliminated.

"Effects of the Invention" As detailed above, the present invention is a method for removing the water vapor film generated on the surface of the object during heating with a radiant heat exchanger plate through means such as exhaust or blowing. Most of the radiant heat transfer is directly irradiated onto the processed material, resulting in a marked improvement in drying efficiency. Furthermore, the relative humidity on and around the surface of the workpiece can be lowered to increase the gradient of water vapor partial pressure, thereby increasing the evaporation rate and speeding up the drying of the workpiece. Furthermore, since the material is suctioned and exhausted through means such as evacuation or blowing, the temperature of the material to be treated is lower than that immediately before suction, but the temperature of the radiant heat exchanger plate does not change much.

Therefore, a large temperature difference occurs between the two, resulting in a large amount of radiant heat transfer (p1), and as a result, the drying rate increases.

[Brief explanation of drawings]

The drawing schematically shows one embodiment of the present invention.
The figure is a front view of the first invention, Figure 2 is a diagram showing the movement of water vapor, Figure 3 is a front view of the main part of the second invention, and Figures 4 and 5 are other examples of the second invention. FIG. 6 is a front view showing the movement of water vapor in the second invention.

Claims (2)

[Claims] (1) In the process in which water-permeable processed materials such as woven fabrics, knitted fabrics, non-woven fabrics, and other water-permeable films pass through a substantially closed-type drying chamber equipped with a radiant heat transfer plate at a predetermined speed, this processed material When more evaporated water vapor is diffused around the material to be treated and a water vapor film is generated, this water vapor film is actively removed to the outside of the drying chamber via the exhaust means, and in the process of moving the material forward. When a water vapor film is generated in the same manner as described above, it is removed in the same manner as described above, and the generation and removal of the water vapor film is appropriately repeated in the process of moving the material to be treated forward. Suction drying method used. (2) In the process in which water-permeable processed materials such as woven fabrics, knitted fabrics, non-woven fabrics, and other water-permeable films pass through a substantially closed-type drying chamber equipped with a radiant heat transfer plate, this processed material is When the more evaporated water vapor is diffused around the object to be treated and a water vapor film is generated, this water vapor film is diffused into the drying chamber through the blowing means and turned into water vapor, and the diffused water vapor is passed through the exhaust means. If a water vapor film is generated as described above in the process of moving the treated material forward, it is diffused and removed in the same way as described above. A suction drying method using radiant heat transfer, characterized in that the generation and diffusion removal of the water vapor film are repeated as appropriate during the process of drying.