JP6230966B2 - Humidity control plate - Google Patents

Description

  The present invention relates to a humidity control plate capable of controlling the humidity inside a power / communication equipment storage box in which a distribution board and an operation panel are stored. More specifically, the present invention relates to a humidity control plate capable of controlling the humidity inside the storage box for power and communication equipment by utilizing the humidity control function of silica gel and preventing condensation.

  In the storage box for power / communication equipment in which the distribution board and operation panel are stored, electrical equipment, electronic components, and the like are stored. When power is supplied, the temperature in the storage box is relatively high and the relative humidity is kept relatively low. However, when the supply of power is stopped, the temperature in the storage box rapidly decreases, and the relative humidity in the storage box increases rapidly. As a result, condensation may occur in the electrical equipment and electronic components in the storage box, and the insulation may cause defective insulation and electrical leakage in the electrical equipment and electronic components due to the condensation. In particular, this tendency is remarkable in storage boxes installed outdoors where the temperature changes drastically.

  Conventionally, a temperature / humidity sensor and a space heater have been incorporated inside the storage box, and measures have been taken to prevent condensation by sensing and controlling the temperature drop (humidity rise) inside the storage box. According to such a method, condensation can be reliably prevented, but there is a problem of power consumption and the like, which is not preferable. As a method that does not use a space heater, a method has been attempted in which a desiccant is placed inside the storage box to absorb excess moisture inside the storage box and prevent condensation, but the desiccant is a material that has only a moisture absorption effect. When the moisture content in the desiccant reaches a saturated state, the moisture absorption capacity is lost, and it is necessary to frequently replace the desiccant.

  In order to solve the above-mentioned problem, as disclosed in Patent Document 1, “a box body, a rubber molded body for humidity adjustment comprising a rubber composition containing non-vulcanized rubber and 40 to 90% by weight of a water-absorbing polymer; And a humidity-adjusted box (Patent Document 1: Claim 1), wherein the humidity-adjusting rubber molded body is disposed inside the box body. That is, a humidity control member made of a rubber composition containing non-vulcanized rubber and 40 to 90% by weight of a water-absorbing polymer is disposed inside a power / communication equipment storage box in which a distribution board or operation panel is stored. Is disclosed.

JP 2003-134618 A

  In the “box whose temperature is adjusted inside (Patent Document 1: title of invention)” according to Patent Document 1, non-vulcanized rubber is used as a base material for dispersing the water-absorbing polymer. Rubber (which is almost the same with non-vulcanized rubber) may be oxidized and deteriorated by ozone, etc., the molecule may be cut by heat (high temperature), and chemical changes may occur due to ultraviolet rays, etc., resulting in deterioration of the rubber and cracks on the rubber surface. Are known. In particular, rubber materials having a double bond in the main chain are said to be susceptible to deterioration such as cracks.

  The humidity control plate according to the present invention is a humidity control plate installed inside a power / communication equipment storage box in which a distribution board or operation panel is stored, and the power / communication equipment storage box is installed outdoors. Yes. Accordingly, rubber molecules are aging (deteriorating) due to heat (high temperature) cutting of rubber molecules and chemical changes due to ultraviolet rays. To make matters worse, a high-voltage current flows inside the power / communication equipment storage box in which the distribution board and operation panel are stored, and the vicinity of the high-voltage current is a place where the ozone concentration is high. That is, ozone generation due to high-voltage current is inevitable, and rubber oxidation due to ozone is inevitable. Therefore, use outdoors is disadvantageous in that the unvulcanized rubber itself tends to age (deteriorate) and lacks durability.

  On the other hand, silica gel is used as a desiccant because it has a porous structure (pore structure) and a large surface area. Silica gel includes A-type silica gel, B-type silica gel, and C-type silica gel. Type A silica gel is used as a desiccant because it absorbs moisture even at low humidity and does not release moisture unless heated. B-type silica gel has a diatomaceous earth property that adsorbs much moisture at high humidity but releases moisture at low humidity, and is mainly used as a humidity control agent. That is, not only the adsorption but also the low moisture can be gradually released. C-type silica gel does not absorb and release much water, and is mainly used for adsorption / desorption of polymer compounds such as proteins and as a catalyst carrier.

  Applicants considered that the above-mentioned characteristics of silica gel can be applied to humidity control plates installed in the storage boxes for power and communication equipment in which distribution boards and operation panels are stored. It led to the invention. An object of the present invention is to provide a humidity control plate that can control the humidity inside the storage box for power and communication equipment by utilizing the humidity control function of silica gel, prevent condensation, and has excellent durability. It is in.

In order to solve the above problem, the invention described in claim 1 of the present application is a humidity control plate in which silica gel as a main component is set with a binder, which is installed inside a storage box for power and communication equipment, The weight ratio of A-type silica gel, B-type silica gel, and C-type silica gel contained in the humidity control plate is 0.1% to 0.5% by weight of A-type silica gel, and 99.0% to 99.8% of B-type silica gel. Wt%, C-type silica gel weight 0.1 wt% to 0.5 wt%, and the binder is a humidity control plate made of hydroxypropylcellulose .

In the present specification, A type silica gel means silica gel having an average pore radius of 20 to 40 mm and a specific surface area of 650 to 750 m ² / g, and B type silica gel means that the average pore radius is 50 to 70 mm. A silica gel having a surface area of 400 to 500 m ² / g and a C-type silica gel are silica gel having an average pore radius of 80 to 120 mm and a specific surface area of 300 to 400 m ² / g.

  The invention described in claim 2 of the present application is the humidity control plate according to the invention described in claim 1, wherein the humidity control plate is formed with a plurality of concave grooves.

  The invention described in claim 3 of the present application is the humidity control plate according to claim 1 or 2, wherein a humidity indicator is provided on the humidity control plate.

  The invention described in claim 4 of the present application is the material according to any one of claims 1 to 3, wherein the surface of the humidity control plate is coated with a photocatalytic substance and / or adsorbs a harmful substance. It is characterized by being a humidity control plate coated with.

  The invention according to claim 1 of the present invention uses a silica gel (A-type silica gel, B-type silica gel, and C-type silica gel) as a main component for starch paste, gum arabic glue, hydroxypropyl cellulose, and various building materials. And a humidity control plate having a humidity control function hardened with a binder such as a resin agent, cement or gypsum.

  By installing the humidity control plate according to the present invention inside the storage box for power / communication equipment, even if the supply of power is stopped and the temperature in the storage box rapidly decreases, the relative humidity in the storage box No longer rises rapidly. As a result, it is possible to eliminate the occurrence of dew condensation on the electrical equipment and electronic components in the storage box and the occurrence of poor insulation and electrical leakage in the electrical equipment and electronic components due to the dew condensation. Moreover, the power consumption can be reduced to zero by installing it as an alternative to the space heater.

  The invention according to claim 2 of the present application is a humidity control plate in which a plurality of concave grooves are formed, and the surface area of the humidity control plate itself is increased. It has become possible to increase the moisture absorption ability and moisture release ability.

  The invention according to claim 3 of the present application is a humidity control plate provided with a humidity indicator, and the degree of moisture absorption / release can be visualized (so-called visualization).

  The invention according to claim 4 of the present application is a humidity control plate in which the surface of the humidity control plate is coated with a photocatalytic substance and / or a substance that adsorbs a harmful substance, and the self-cleaning function is provided on the surface of the humidity control plate. And a function of adsorbing and removing harmful substances can be added.

It is a whole perspective view of a humidity control plate. It is the figure which showed the use condition of the humidity control plate. It is a figure showing the weight change by moisture absorption / release of a humidity control plate.

<Structure and manufacturing method of humidity control plate>
Hereinafter, the humidity control plate 10 for a distribution board and a distribution board storage box according to the present invention will be described in detail with reference to FIGS. FIG. 1 is an overall perspective view for explaining the structure of the humidity control plate 10. In this embodiment, the humidity control plate 10 has a rectangular plate shape with a length of 500 mm, a width of 300 mm, and a thickness of 10 mm. Further, as can be seen from the cross-sectional view, four rows of concave grooves 20 are provided on the front side (the side that can be seen when installed in the distribution board and distribution board storage box). Further, a humidity indicator 30 is installed near the lower right side of the front side of the humidity control plate 10 (the side that can be seen when installed in the distribution board or distribution board storage box). Although not shown, the surface of the humidity control plate 10 may be coated with a photocatalytic substance or a substance that adsorbs a harmful substance (shell powder such as pearl oyster or clam).

  The humidity control plate 10 according to the present invention comprises various silica gels (A type, B type, C type) in a predetermined weight ratio (A type silica gel 0.1 wt% to 0.5 wt%, B type silica gel 99.0 wt%). % To 99.8% by weight, C-type silica gel weight 0.1% to 0.5% by weight), and a binder is further added (20 parts by weight of binder to 100 parts by weight of silica gel). To do. As the binder, starch glue, gum arabic glue, hydroxypropyl cellulose, or the like is used. In addition to these, paste materials and resin agents used for manufacturing various building materials, hydraulic materials such as cement and plaster, and the like can also be used. Among the binders, hydroxypropylcellulose is most suitable for the finished humidity control plate 10, which is difficult to break and can be easily cut by cutting with a cutter or the like. In addition to the binder, a coloring agent, an antibacterial agent, a deodorizing agent, and the like can also be added.

  As a molding method of the humidity control plate 10 for the distribution board and the distribution board storage box, cast molding using a mold, press molding, extrusion molding for extruding a kneaded product of the molding material from the die, and the like can be employed. Further, the binder containing the molding material can be molded by heating and melting. Among these, from the viewpoint of mass productivity, it can be said that extrusion molding is the most efficient. The molded body of the humidity control plate 10 is manufactured through a drying process for removing excess water after the molding and a curing process for promoting the curing of the molded body. Furthermore, it can also be set as a sintered body by baking a molded object at high temperature.

<How to use humidity control plate>
FIG. 2 is a diagram illustrating a usage state of the humidity control plate 10. As shown in FIG. 2, the humidity control plate 10 is attached to the inner wall of the door of the electric / electronic device storage box body. The number of humidity control plates 10 disposed in the electric / electronic device storage box body is not particularly limited, and only one plate may be disposed in accordance with the external environment such as the climate depending on the installation location of the electronic device storage box body. Well, there may be multiple sheets. The planar shape of the humidity control plate 10 is usually rectangular. However, the planar shape of the humidity control plate 10 is not particularly limited, and the humidity control plate 10 may be cut and processed as appropriate for convenience. And circular shape, elliptical shape, or elliptical shape etc. may be sufficient.

  The conditions under which condensation occurs in the electrical / electronic device storage box are determined by the outdoor environment in which the storage box is placed, the specification of the storage box, and the like. As outdoor environmental factors, temperature, humidity, and rainfall can be considered. Specifications that are considered to affect the conditions in which condensation occurs in the storage box itself include the installation condition of the door packing, the sealing state of the cable hole, and the degree of opening relative to the volume of the storage box. The humidity control plate 10 according to the present invention can prevent dew condensation by installing the required humidity control plate 10 in the electrical / electronic device storage box in accordance with the environmental factors described above.

<Hygroscopic and moisture release mechanism of humidity control plate according to the present invention>
Generally, the types of silica gel are roughly classified into A type silica gel, B type silica gel, and C type silica gel. Of property differences, A-type silica gel having an average pore radius of the specific surface area 20~40Å 650~750m ² / g, an average pore radius of specific surface area 50~70Å is 400~500m ² / g B type Silica gel is classified into C-type silica gel having an average pore radius of 80 to 120 mm and a specific surface area of 300 to 400 m ² / g.

  There are two types of adsorption action of silica gel, surface adsorption and capillary condensation, both of which are reversible. In surface adsorption, adsorbate such as water is chemically adsorbed on the surface of silica gel by van der Waals force or hydrogen bond, and a large number of hydroxyl groups on the surface of silica gel play a major role. On the other hand, in capillary condensation, moisture and the like are physically adsorbed to the pores by capillary action. Silica gel is adsorbed mainly by surface adsorption when the relative humidity is low, and is said to be performed by capillary condensation as the humidity increases.

  The present invention is a humidity control plate 10 used inside a storage box for power / communication equipment in which a distribution board or operation panel is stored, and the ideal function required is to quickly absorb moisture at high humidity. Moisture absorption inside the humidity control plate 10, lower the relative humidity to a level where condensation does not occur, and when the inside of the storage box for power / communication equipment becomes low humidity, water is not kept inside the humidity control plate 10, Is to release the moisture to the outside of the humidity control plate 10 to restore the moisture absorption capability of the humidity control plate 10 itself.

  The graph of FIG. 3 shows that at 25 ° C., 0 hour (starting time) to 24 hours in a relative humidity RH 95% environment (high humidity environment), and then 24 to 48 hours in a relative humidity RH 50% environment (low humidity environment). The humidity control plate 10 according to the present invention is allowed to stand and the change in weight is measured. Looking at the experimental results, it can be seen that when the A-type silica gel content in the humidity control plate 10 is high, the moisture absorption amount increases, but the ability to release moisture almost disappears (see curve a in FIG. 3). On the other hand, when the C-type silica gel content in the humidity control plate 10 is increased, the moisture absorption amount decreases, but when placed in a low-humidity environment, there is a tendency that the moisture is completely released without time (FIG. 3). Curve e). The B-type silica gel exhibits characteristics intermediate between those of the A-type silica gel and the C-type silica gel, and has a moisture absorption / release curve characteristic closer to the ideal than the A-type silica gel alone and the C-type silica gel alone (curve d in FIG. 3). ) Is a function required for the humidity control plate 10 used inside the storage box for power / communications equipment (at high humidity, moisture is absorbed into the humidity control plate 10 earlier, and the relative humidity is reduced to a humidity at which condensation does not occur. It is understood that the amount of moisture absorption at 0h to 4h is insufficient.

  From the experimental results shown in FIG. 3, the weight ratio of A-type silica gel: B-type silica gel: C-type silica gel suitable for the humidity control plate 10 for distribution boards and distribution board storage boxes is A-type silica gel: B-type silica gel: C. It can be said that the type silica gel is preferably 0.1 to 0.5% by weight: 99.0 to 99.8% by weight: 0.1 to 0.5% by weight. In particular, in the case of A type silica gel: B type silica gel: C type silica gel = 0.5 wt%: 99.0 wt%: 0.5 wt% (curve c in FIG. 3), the moisture absorption is from the viewpoint of preventing condensation. When it is sufficient and the moisture absorption rate is fast (ie, the rise of the moisture absorption curve is large) and condensation is likely to occur due to a rapid temperature change, A type silica gel with higher hygroscopicity than B type silica gel is contained (although it is a small amount). Therefore, it absorbs almost instantaneously (the amount of moisture absorption at 0h to 4h is larger than that of B-type silica gel alone), and the amount of moisture release is also almost completely absorbed (48 h in curve c in FIG. 3). It can be said that it can withstand repeated use. That is, in order to use the humidity control plate according to the present invention as the humidity control plate 10 for a distribution board and a distribution board storage box, an appropriate silica gel ratio contained in the humidity control plate 10 (A type silica gel: B type silica gel: C-type silica gel) can have a high humidity control function as a humidity control plate used inside the storage box for power and communication equipment.

  That is, as can be seen from the experimental results, in order to ensure the function to be used inside the power / communication equipment storage box in which the distribution board and operation panel are stored, humidity control containing only B-type silica gel The plate cannot be said to be sufficiently satisfactory in terms of moisture absorption ability and moisture release ability. In the present invention, the humidity control plate 10 having a blend ratio capable of complementing the defects of the humidity control plate 10 containing B type silica gel alone is developed by incorporating the characteristics of the A type silica gel and the C type silica gel into the B type silica gel. did.

<Effect of humidity control plate>
By installing the humidity control plate 10 according to the present invention inside the power / communication device storage box, even if the supply of power is stopped and the temperature in the storage box rapidly decreases, the relative humidity in the storage box Humidity has not increased rapidly. As a result, it is possible to eliminate the occurrence of dew condensation on the electrical equipment and electronic components in the storage box and the occurrence of poor insulation and electrical leakage in the electrical equipment and electronic components due to the dew condensation.

  Moreover, since it is the humidity control plate 10 in which the several ditch | groove 20 is formed, and the surface area of the humidity control plate 10 itself is large, the moisture absorption capability inside the storage box for electric power / communication equipment is correspondingly increased. It became possible to raise. Furthermore, it is the humidity control plate 10 in which the humidity indicator 30 is installed, and the degree of moisture absorption / release can be visualized (so-called visualization). From the standpoint of maintenance-free, the humidity control plate 10 is a humidity control plate 10 in which the surface of the humidity control plate 10 is coated with the photocatalytic substance 40 and / or the substance 50 that adsorbs harmful substances. The photocatalytic substance is easily adsorbed and fixed in the C-type silica gel. Therefore, the self-cleaning function and the harmful substance adsorption / removal function are added to the humidity control plate 10. Can now.

<Change example of humidity control plate for distribution board and distribution board storage box>
The configuration of the humidity control plate 10 according to the present invention is not limited to the aspect of the above embodiment, and includes the configuration of the groove 20, the humidity indicator 30, the photocatalytic substance 40, the substance 50 that adsorbs harmful substances, and the like. The present invention can be changed as appropriate without departing from the spirit of the present invention.

  Below, the Example of the humidity control plate 10 for a distribution board and a distribution board storage box which concerns on this invention is described. First, silica gel (A-type silica gel, B-type silica gel, C-type silica gel) is blended (each blended in Examples 1 to 10). Furthermore, 20% by weight of hydroxypropylcellulose as a binder is added to the total weight of the silica gel, and water is mixed by adding 10 to 20 times (weight ratio), preferably about 15 times the solid content of the above various materials. Then, a slurry is formed, and the resulting slurry is extruded to produce a humidity control plate green plate. The green plate is pressure-dehydrated and then cured and cured. The humidity control plate is evaluated at 25 ° C. in a humidity RH 95% environment for 0-24 hours and in a relative humidity RH 50% environment for 24 hours to 48 hours to evaluate moisture absorption / release characteristics each time. The change in the weight of the humidity control plate was measured. The implementation results are summarized in Table 1.

  Since the humidity control plate according to the present invention exhibits excellent effects as described above, it can be suitably used in the field of humidity control plates for distribution boards and switchboard storage boxes.

10. ・ Humidity control plate 20. ・ Dove groove 30 ・ ・ Humidity indicator 40 ・ ・ Photocatalytic substance 50 ・ ・ A substance that adsorbs harmful substances

Claims (4)

It is a humidity control plate that is installed inside a storage box for electric power and communication equipment, in which silica gel, the main component, is hardened with a binder,
The weight ratio of A-type silica gel, B-type silica gel, and C-type silica gel contained in the humidity control plate was 0.1% to 0.5% by weight of A-type silica gel, and 99.0% to 99.% by weight of B-type silica gel. 8 wt%, C-type silica gel weight 0.1 wt% to 0.5 wt%,
The humidity control plate, wherein the binder is hydroxypropylcellulose .   The humidity control plate according to claim 1, wherein a plurality of concave grooves are formed in the humidity control plate.   The humidity control plate according to claim 1, wherein a humidity indicator is installed on the humidity control plate.   The humidity control plate according to any one of claims 1 to 3, wherein a surface of the humidity control plate is coated with a photocatalytic substance and / or a substance that adsorbs a harmful substance.

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