JPS6050736B2 - double glazed windows - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Double-glazed windows are arranged in 1 Window Performance, Design and Installation J by Beckett and GOdfrey, published by Van Nostrand Reinhold, New York, 1974JF. has been used from time to time.

A double-glazed window consists of two parallel panes spaced apart to allow air space;
having a perimeter of space enclosed between the panes by a moderately flexible sealant extending along their perimeter, the perimeter holding the panes apart; , and forming a generally right parallelepiped space between the two panes. Polybutene resins and polyfide resins are common as sealants in double-glazed window construction. used in The purpose of double-glazed windows is thermal and soundproofing.

Beckett and Gottsfrey describe the water contained in the air space between two window panes, which occurs when the temperature of the air space falls below its dew point. It describes the problem of vapor condensation, and for J-windows, condensation occurs on the surface of the glass, on the formwork facing the room, and in the case of double-glazed windows, in the space between the two panes of glass. It also happens within. Whenever condensation occurs, a tricky problem arises. That is, visibility is now impaired and paint and window moldings deteriorate. It is written as yo. They also describe placing dehydrating and desiccant agents, such as silica gel, in the space to adsorb moisture from the trapped air and reduce condensation. Double glazed windows (usually termed sealed insulated glass) are windows that are placed in the space between two panes and in close proximity to a sealing resin that holds both of these panes apart. It has an elongated solid adsorbent that is installed in the same direction.

The solid adsorbent is usually held in a generally rectangular aluminum tube, perforated or not completely sealed, so that the sealed air comes into contact with the adsorbent, and the adsorbent is hermetically sealed in an insulating glass tube. Installed along all or part of the interior perimeter. Years of experience has shown that water vapor condensation is not just a condensation problem that occurs when using double-glazed windows, but also that over time organic sealants decompose and condense on the inner surface of the window glass. The problem is the generation of condensable vapors such as hydrocarbons or organic sulfides.

It is recent practice to use synthetic zeolites (sometimes referred to as molecular sieves), silica gel, activated alumina, or mixtures of synthetic zeolites and a second adsorbent such as silica gel as adsorbents to reduce condensation. The use of a second adsorbent to supplement the large pore molecular sieve adsorbent is based on the following observational results: water vapor is rapidly absorbed by the molecular sieve. All molecular sieves that have been used allow nitrogen and oxygen molecules to enter the pores of the adsorbent along with water vapor molecules. The use of molecular sieve zeolites with this property poses a problem that does not seem to have been previously recognized, but if Problems have arisen that have been ignored or for which no answers have been proposed until now.

As a result of recent concerns about energy issues, the use of double-glazed windows has increased significantly beyond its current use, primarily in glass-encased high-rise buildings, and has expanded widely in homes and apartments. There is an emerging trend of usage.

Double glazed windows must be designed to provide maximum efficiency and longevity, as their use is certainly increasing greatly, and they are equipped with adsorbents that adsorb not only water vapor but also nitrogen and oxygen. Problems that arise during use can no longer be ignored.

The problem is as follows.

In the northern part of the temperate region, the temperature of the air trapped between the two panes of a double-glazed window can easily reach 43.4°C (110°F) or higher during hot summer days and days, and during cold winter nights. The temperature can drop below -17.8°C (0°F). At low temperatures in this range, currently used molecular sieve zeolites adsorb not only water vapor but also large amounts of oxygen and nitrogen. At high temperatures, the adsorbed oxygen and nitrogen tend to be released from the adsorbent and return to the gas space trapped between the two panes. Due to the adsorption-deposition cycle that occurs with temperature changes such as day-night changes and seasonal changes,
Significant changes occur in the pressure of the air trapped between the panes. The pressure of trapped air typically varies by more than 6% simply as a result of oxygen and nitrogen adsorption or desorption. This change in pressure is of course increased by temperature effects. For example, increasing the temperature not only desorbs nitrogen and oxygen from the currently used molecular sieve zeolites, but also increases the temperature itself, trapping nitrogen and oxygen between two relatively hard panes. The pressure of the trapped gas increases. Conversely, when the temperature decreases, the adsorption of nitrogen and oxygen increases, the pressure of the gas trapped between the two window glasses decreases, and as the temperature itself decreases, the trapped gas increases even more. pressure decreases. This continuous variation in pressure distorts the view through the double-glazed window to some extent, and furthermore, the glass itself moves back and forth, causing damage to the two resin-formed panes. The seal between them tends to weaken, and the best! Eventually, a passageway will be formed between the outside air and the trapped air through the sealing resin, allowing more or less outside air to enter and exit the confined space, resulting in the loss of the outside air over time. The capacity of the adsorbent to absorb additional water vapor and air introduced through the air inflow and outflow is exhausted. According to the invention, the adsorbent placed along the periphery of the space enclosed by the two panes of a double-glazed window is a mixture of two adsorbents. One of the adsorbents is a molecular sieve zeolite that strongly adsorbs water vapor, allowing water vapor molecules to enter the pore space of the adsorbent, but preventing nitrogen and oxygen molecules from entering that space. It is the diameter of the hole. One particular adsorbent that meets this requirement is manufactured by Union Carbide Corporation and W.R. Grace & Co.
) is a commercially available tate-type molecular sieve. This material has an average pore diameter of about 3 angstroms, strongly and reliably adsorbs water vapor, and does not adsorb either oxygen or nitrogen. The chemical composition of this particular molecular sieve is the formula: K9Na3
(AlO2l.

(SiO2)1. -XH2O. The water content of the composition will vary according to the degree of drying or activation of the zeolite, but should not exceed about 1.5% by weight of the total composition at the desired activated state. Other adsorbents suitable for this application are obtained by starting with a sodium zeolite having an average pore diameter of about 4 angstroms and replacing a substantial portion of the sodium with potassium. The resulting potassium or partially potassium sieve has a reduced pore diameter that allows the ingress of water vapor molecules but excludes the ingress of nitrogen and oxygen molecules. The second component of the adsorbent is silica gel or activated alumina having an average diameter capable of adsorbing benzene vapor.

Such silica gels or activated aluminas are used to seal the perimeter of double-glazed windows, and the polysulfide or polyolefin resins that cause staining or staining of the inner surface of the window panes slowly decompose, resulting in the sealing of the two panes. installed in the air space to adsorb hydrocarbon and/or organic sulfide vapors released into the space confined between the glass, if these vapors are not rapidly removed from the space. be. Activated carbon also works effectively as a second adsorbent, but because of its special color, care must be taken to keep it out of the periphery of the interior space of a double-glazed window. If desired, a mixture of two or more of silica gel, activated alumina and activated carbon can be used as the second adsorbent. Molecular sieve zeolite, currently commonly known in the art as Type A molecular sieve zeolite, is described in U.S. Pat.
It is described in No. 2243. A type zeolite is 11A
an inner central hollow part of diameter i.e. Cage
) is a flat-headed cuboctahedron. The hollow portion enters through a much smaller diameter annular opening, the diameter of which is determined by the particular cation it contains. For example, Buddha-type molecular sieve zeolite type: Nal2 [
(AlO2)1. (SiO2)1. ]XH2O. When fully hydrated, X is 27, the sieve is activated and adsorption capacity is developed by heating and driving out water until the water content of the total composition falls below 1.5% by weight. do. The French sheave has an opening approximately 4A in diameter.
When a substantial proportion of the sodium content of the French sieve is replaced by potassium, its orifice diameter is reduced to about 3A. For example, a Tate-type molecular sieve is formed by replacing the sodium in a French-type sieve with potassium;
Its formula is K9Na3[(AlO2)12(SiO2)1
. ]・XH2O. ? The type molecular sieve has an opening with a diameter of 3. Other molecular sieves, such as the hollow type, 10X type, and 13X type, have larger openings. The diameter of the opening directly determines which molecules enter the hollow part of the zeolite through the opening and are adsorbed.

It is expected that a molecular sieve with an opening of 4A will allow the entry of molecules with a kinetic diameter smaller than 4A and exclude molecules with a kinetic diameter larger than 4A from entering the hollow section. Ru. The problem of entry and exclusion, however, is not always so simple. Breck and Smith are 1 Scientific
A] 11erican), in the January issue of 195, 1
Molecules larger than 3.5 angstroms in diameter are (3.5
A-type sheep with an opening diameter of angstroms)
Although we can penetrate crystals, it's not always that simple in reality. We know, for example, that an ethane molecule with a diameter of 4 angstroms can pass through an aperture of 3.5 angstroms at normal temperatures, but with a diameter of 4.
It was found that a 9 angstrom propane molecule cannot pass through. This is clear enough if we remember that atoms do not have solid bodies. Those atoms are just like pulsating rubber balls. The pulsations of both the aperture atoms and the incoming molecules combine to form an effective diameter of the aperture that is significantly larger than the free diameter of 3.5 Angstroms. Furthermore, the kinetic energy of the entering molecules allows them to enter through the opening. We have generally found that molecules up to 0.5 angstroms wider than the free diameter of the opening can easily pass through the opening at normal temperatures. Larger molecules have increasing difficulty entering the crystal, ie, molecules 1 angstrom larger cannot enter at all. It says something. The materials cited above are difficult to form into molecular sieve zeolites that, in terms of opening diameter and molecular dynamic diameter, allow the entry of certain molecules but exclude others. Show that. To find out whether a molecular sieve with a given aperture diameter will allow the entrance of molecules that have a kinetic diameter larger than the aperture and which is not more than 1 angstrom larger than the aperture. It is necessary to conduct a simple test in which the molecular sieve acts on substances that are expected to be excluded, and to determine whether they are allowed to enter or are excluded. The tower-shaped molecular sieve allows water molecules to enter and adsorb them, and excludes oxygen and nitrogen molecules.

The minimum kinetic diameter of water molecules is reported to be 256 A, and the minimum kinetic diameters of oxygen and nitrogen are 3.46 and 3.
．． It is reported to be 64A. Molecular sieves prepared by substituting some of the sodium in French sieves with potassium replace less than half of their sodium to determine whether the molecular sieves allow or exclude the ingress of nitrogen and oxygen. Perform a simple test. The adsorbent used in double-glazed windows to control the condensation of water vapor and hydrocarbons or organic sulfides on the inner surface of the window glass is a tate-type molecular sieve zeolite with a pore diameter large enough to adsorb benzene molecules. silica gel adsorbent.

These adsorbent mixtures must contain at least about 15% by weight of packed molecular sieve zeolite and at least about 25% by weight of silica gel or activated alumina.

Both adsorbents are in the form of small particles of 10 to 30 mesh. This size is not critical, however, sizes in this range are convenient for filling porous aluminum tubes installed along the interior perimeter of double glazed windows. The amount of adsorbent mixture that is theoretically required to control water vapor condensation and hydrocarbon condensation is quite small; .44 x 152.40 cm (3 x 5 feet)
Somewhat less than 7 da for double glazed windows.

Therefore, the sealing of the two panes of a double-glazed window is slightly incomplete, which can hardly prevent water vapor from the outside air from entering the interior space, and during the curing of the resin, carbonization Because hydrogen or organic sulfides are rapidly released, it is necessary to remove these vapors rapidly, and because customers require long-life warranties for double-glazed windows, the surrounding interior spaces must be The amount of adsorbent placed along the window is about 0.01 to 1.3 cm per 16.38 c71 (11 n3) of air trapped between two panes.
The quantity must be in the range 0y. Higher amounts can be used if desired, but there is usually no benefit in doing so. Preference is given to using a mixture of granular molecular sieve zeolite and granular silica gel, activated alumina or activated carbon.

On the other hand, the prevention of pressure fluctuations caused by the adsorption and desorption of nitrogen and oxygen, and at the same time the effective reduction of condensation, can be achieved by filling certain rectangular aluminum tubes with molecular sieve zeolite and using other is filled with a second adsorbent, then a zeolite-filled tube is placed along one or more peripheral sides of the confined space between the two panes, and the tube is filled with a second adsorbent. This is achieved by installing the pipes along the remaining perimeter sides. Furthermore, the filling of a rectangular aluminum tube is not only carried out by injecting particulate adsorbent into the tube, but also, if desired, with a rod-shaped mold of a size that allows the adsorbent to be slid into the aluminum tube. Most double-glazed windows manufactured today combine polyolefin or polysulfide resins with adsorbent-filled aluminum tubes to maintain the spacing between the two panes and Sealing the surfaces of the spaces trapped between these panes.

Claims (1)

[Scope of Claims] 1. Two parallel panes spaced apart to occupy a right-angled parallelepiped space, the two panes being sealed to confine an air space. in a double-glazed window having a periphery of , and further comprising a molecular sieve zeolite adsorbent disposed along all or part of the inner periphery of said trapped air space. A double-glazed window characterized in that a molecular sieve zeolite is used as an adsorbent, with pore openings such as to allow the entry of oxygen and nitrogen into the pore spaces, but exclude the entry of oxygen and nitrogen into the pore spaces. 2 having two parallel window panes spaced apart to take up a right-angled parallelepiped air space, the two panes being sealed with a flexible resin to close the air space; In a double glazed window having a periphery and further comprising an adsorbent disposed along all or part of the periphery of the confined air space to prevent condensation forming on the inner surface of the pane, A granular molecular sieve zeolite with an average pore diameter that allows the ingress of water molecules but prevents the ingress of nitrogen and oxygen, and an average pore diameter that has a strong affinity for hydrocarbons and allows the ingress of benzene molecules. using as adsorbent a mixture with a particulate non-zeolite adsorbent having Double-glazed windows characterized by the substantial elimination of pressure changes in the space. 3. In the double-glazed window according to claim 2, the molecular sieve zeolite is a type 3A molecular sieve zeolite, and the non-zeolite adsorbent having a strong affinity for hydrocarbons is silica gel. ,
A double-glazed window characterized in that it is made of activated alumina, activated carbon or a mixture thereof. . 4. The double-glazed window according to claim 2, wherein the adsorbent mixture consists of 15 to 75% by weight of granular molecular sieve zeolite, the remainder being granular silica gel, granular activated alumina, or a mixture thereof. and the particle size of both adsorbents is about 10 to 3
A double-glazed window characterized in that it is in the range of 0 mesh. 5 A window with two parallel window glasses spaced apart to occupy a right-angled parallelepiped air space, and sealed with a flexible resin to confine the air space.
a periphery of the pane, and an adsorbent is disposed along all or part of the circumference of the confined air space to prevent condensation from forming on the inner surface of the pane. A molecular sieve zeolite with an average pore diameter that allows the ingress of water molecules but prevents the ingress of nitrogen and oxygen is used as the adsorbent disposed along a portion of the periphery in a double-glazed window. , and the adsorbent disposed along the remainder of the periphery is a non-zeolitic adsorbent that has a strong affinity for hydrocarbons and has an average pore diameter that allows the ingress of benzene molecules. A double-glazed window characterized by: