JP2013534303A - Improvements to solar collector collector tubes. - Google Patents

Abstract

  The present invention is improved with a getter system (10) comprising one or more getter materials in the form of pills (11, 11 ′, 11 ″...) Received in a single line in a suitable holder. Related to solar collector tubes.

Description

  The present invention relates to improvements to solar collector tubes.

  Solar collectors are becoming an increasingly important alternative energy source. In these devices, and more specifically in the solar collector tubes, the presence of hydrogen increases heat conduction from the central tubular body through which the heat removal fluid flows to the outside of the collector tube, and therefore its efficiency. The presence of hydrogen is harmful. Since the fluid flowing through the central tubular body tends to decompose at high temperatures and produce hydrogen, the problem with the presence of hydrogen is a particularly relevant problem in this case.

  Even in the new generation of collectors that utilize different fluid types to remove heat at higher temperatures, more hydrogen gas is released from the metal portion of the collector at such higher temperatures, so Problems related to existence and the resulting degradation of device characteristics are particularly problematic.

  There are additional problems associated with high internal temperatures in the heat collection tube that make the getter material unfavorable operating conditions with respect to hydrogen capacity, which is inversely proportional to the operating temperature.

  For this reason, several technical means as disclosed in Patent Document 1 have been developed. In Patent Document 1, a getter material is arranged in a heat collecting tube, and in order to efficiently accommodate the getter material, Describes a configuration that takes shape, the purpose of which is to shield the getter material from solar radiation and the part of the collector that reaches the highest temperature.

  This type of configuration usually has some disadvantages because a standard, i.e., 10 mm diameter, pill-shaped getter material consisting of compressed powder is utilized, which is sufficient in the heat collection tube. In order to introduce a quantity of getter material to ensure proper device operation over 20-30 years, all sleds imply that it will contain two pill lines, usually in each collector tube Accommodates two sleds.

  This causes two problems of different nature, on the one hand, the problem of greater difficulty in loading getter material in the form of two getter pill lines adjacent to each other, on the other hand, contacting each other, The problem is that the number of contact points of the pill that comes into contact with the sledge wall increases.

  These contact points selectively create areas that are fragile, resulting in a powder. The generation of powder and subsequent desorption from the pill is a phenomenon that should be minimized as much as possible even when the powder is confined by a suitable confined metal mesh. These detached powders cause problems not only in terms of aesthetics but also in terms of function (for example, the transparency of the surface exposed to radiation is degraded, resulting in a decrease in the thermal efficiency of the heat collection tube).

US Pat. No. 6,832,608 U.S. Pat. No. 3,320,901 U.S. Pat. No. 4,306,887 British Patent No. 2077487 US Pat. No. 5,961,750 International Publication No. 2007/148362 International Publication No. 2007/099575 International Publication No. 2010/105945

  The object of the present invention is to mitigate the severity of this phenomenon.

  The object of the present invention is to mitigate the severity of this phenomenon, and in its first aspect, the present invention comprises a solar heat collecting system comprising a getter system comprising a mechanical support and a pill of compressed powder of getter material. In the collector tube, the mechanical support comprises a holder consisting of a bottom and two lateral shoulders, the getter powder pill has a diameter of 15 mm or more, the diameter / height ratio consists of 2-5, The pills are characterized in that they are received in the holder at the bottom of the holder in a single line.

  The previously referenced holder of the getter system can also be referred to as a U-shaped sled, and for the purposes of the present invention, the two terms have equivalent meanings.

  The invention is described below with the help of the following drawings.

1 is a side view of a first embodiment of a getter system to be used in a heat collection tube according to the present invention. FIG. 1 is a plan view of a first embodiment of a getter system to be used in a heat collecting tube according to the present invention. FIG. FIG. 6 is a side view of an alternative embodiment of a getter system to be used in a heat collection tube according to the present invention. FIG. 6 is a plan view of an alternative embodiment of a getter system to be used in a heat collection tube according to the present invention. FIG. 3 shows some possible embodiments for an elastic element to be used in a mechanical support. FIG. 4 is a plan view of a getter system to be used in a heat collecting tube that incorporates one of the elastic elements shown in FIG. 3. FIG. 6 is a cross-sectional view of another embodiment of a getter system to be used in a heat collection tube.

  In the drawings, the dimensions and ratios of the elements are not limited, but are particularly accurate when referring to the dimensions of the metal mesh openings, and have been changed to make the illustration of the invention easier to understand. In addition, some optional elements such as, for example, an optional heat shield, or a securing means for the holder / sledge are not shown because they are not essential to understanding the present invention.

  According to the present invention, the operation of loading the getter material pill into its housing holder is greatly simplified.

  It should be understood that increasing the surface area of the getter material pill degrades the properties compared to a pill with a small surface area. Nevertheless, this degradation is compensated by the above-mentioned advantages that are specifically associated with the technical field, namely solar collector tubes.

  In fact, if the pill surface increases at the same height, it becomes fragile and difficult to handle as a result, while increasing the height will adversely affect the pumping speed and cause an increase in pill internals. There is a problem of encountering gaseous impurities when reaching the region. Therefore, those skilled in the art have not adopted such a solution due to the adverse effects expected when adopting a pill with an increased diameter. It should also be emphasized that the getter pills to be used in the present invention are obtained by appropriately compressing the powder of the getter material, so that they do not contain a binder. For example, it affected the capacity of the material, meaning the amount of hydrogen adsorbed by each pill. This is a fundamental aspect that affects pill structure resistance and related constraints for successful use in solar collector applications.

  Considering the reverse phenomenon described above, the optimum ratio of pill diameter to its height is 2-5, and for exactly the same reason, problems begin to appear for pills with diameters greater than 35 mm.

  The pill diameter is preferably 18 mm to 25 mm, and the ratio of the diameter to the height is preferably 3 to 4. By operating with a pill loaded holder with such dimensional characteristics, by using only one holder / sled, a sufficient amount of getter material that can guarantee a device life of 20-30 years It can be inserted into the heat collecting tube. On the other hand, the currently utilized configuration assumes the use of two different holders for each heat collection tube, and not only the holder but also the element that completes the mechanical support, ie the confined metal mesh In addition to the structural costs of including spacers and appropriate heat shields, there are problems associated with positioning and securing.

  Also, the holder preferably has a width that is 1 to 3 mm wider than the pill diameter, which allows the pill to adapt to some extent within the holder, resulting in a pill structure as a result of hydrogen sorption by the getter material. Solve the technical problems associated with swelling.

  Further preferred embodiments that envisage the use of a wire mesh as the upper closure system for the holder, such as element 14 in FIG. 1B, with respect to the height of the holder, meaning the height of the elements that make up the side shoulders. Then, the height of the side shoulder is 0.5 mm to 1 mm lower than the pill height. This ensures that the net itself also acts as a deterrent element for the getter material pill, limiting its reciprocation, and the possibility that the pill will break as a result of collisions, thereby increasing powder production. To do.

  As in the case of element 23 shown in FIG. 2A, the shoulder height is 1 mm to 3 mm higher than the pill height for exactly the same reason, and for the above technical effect, if part of the upper closure system is rigid. It is preferable.

  In a further preferred embodiment, the holder also includes one or more elastic elements that are in direct contact with the one or more getter material pills.

  The main function of these elastic elements is to apply an appropriate compressive force to the pills so that the pills press against each other. This effect is due to the compression exerted by the elastic element causing the pill to move within the holder, even when the getter pill is larger than the size of the getter pill, its most useful representation being contained within the sled. prevent.

  If the pressure value is excessive, the pill structure will be destroyed instead of preventing the pill from moving in the holder, so the applied pressure value is an important parameter. Strictly speaking, it depends on the application field and is specifically related. The determination of such values is further made difficult by the fact that it takes into account the expansion of the pill as a result of hydrogen sorption by the getter material and the increased pill structure vulnerability as a result of hydrogen sorption. The inventor has found that the compressive force applied by the elastic means should be between 50N and 150N. This value was examined and measured in a newly introduced getter system and therefore when the getter material pill can be considered "new", i.e., it has adsorbed only a minimal amount of hydrogen.

  Furthermore, in order to avoid having selective powder production spots, the elastic elements should be free of angular corners in the contact area with the getter material pill, so that these elastic elements are not in contact with such In place, it should give a flat or rounded surface. Such a feature is hereinafter referred to as “dispersed contact”.

  As for the getter material, a material showing a good hydrogen sorption capacity is preferable even when used at a high temperature.

  Therefore, preferred getter materials useful for the present invention include Patent Document 2 (Zr—Al alloy), Patent Document 3 (Zr—Fe alloy), Patent Document 4 (Zr—V—Fe alloy), and Patent Document 5 (Zr). -Co-rare earth alloys). For example, the use of yttrium alloys is also known, particularly for hydrogen sorption at high temperatures, as described in US Pat. Nos. 6,099,575 and 2010/105945. While the above getter alloys are preferred materials for use with the present invention, any hydrogen getter material can be utilized with the disclosed inventive concepts. Furthermore, it can be envisaged to use pills formed with several different getter materials, or the holder can be loaded with different types of pills.

  1A and 1B show a first embodiment for a getter system 10 for a solar collector tube, where the pills 11, 11 ', 11 "... of the getter material are of the holder. Aligned on the flat bottom 12, there is a confining wire mesh 14 and is fixed to the holder, for example by electric welding.

  In the configuration shown in FIG. 1, there is also an optional element 15, which acts as a stopper and operates mechanically when the pill is loaded into the holder. FIG. 1A shows only one of such elements 15 near one of the holder ends, but the second end also has a second locking element as shown in FIG. 1B. There can be 15 ′.

  The wire mesh can be fixed to the holder in various ways, for example it can be fixed on the holder lateral shoulder 13, 13 'or it can be wrapped on the outer surface of the holder and fixed at the flat bottom 12. be able to. In this second case, according to a preferred fixing configuration, the edges of the mesh 14 are slightly overlapped and then a single electric weld is performed to fix the mesh 14 to the holder.

  As shown in FIGS. 1A and 1B, the wire mesh is arranged not to cover the entire length of the holder in order to avoid interfering with the feasible means needed to secure the holder in the heat collecting tube. So that the end can be left open.

  2A and 2B show an alternative embodiment, where the getter system 20 includes getter material pills 21, 21 ′, 21 ″... Disposed at the bottom of the holder structure, the structure being It is closed by a cover 23 including an opening, and a metal mesh 22 is disposed in the opening.

  Thereafter, although not shown, the cover 23 is fixed to the holder bottom by an appropriate fixing means such as a clew, for example.

  In FIG. 2A there are also several tabs 24 that are folded to serve as stoppers for the getter material pills 21, 21 ′, 21 ″.

  This configuration allows for the production of a closed holder structure with a semi-finished holder cover on which a metal mesh is secured, thus simplifying the assembly of the getter system used in the present invention. Have advantages.

  Also in the second embodiment, in a preferred implementation, the width of the holder is slightly wider relative to the pill diameter and its side shoulder height is slightly lower than the pill height. Also, in this case, it is assumed that a preferable dimension is to use a holder having a width that is 1 mm to 3 mm wider than the pill diameter and a side shoulder height that is 0.5 mm to 1 mm lower than the pill height. In this embodiment, the pill stopper 24 also serves the purpose of applying a slight longitudinal pressure on the pill line, thereby restricting the pill from moving laterally.

  As far as the properties of the wire mesh used in the system according to the invention, such as the wire mesh represented in FIGS. 1A, 1B, 2A and 2B described above, is concerned, the mesh has a size of 10 μm to 500 μm. Holes, more generally gaps. The wire mesh opening is preferably composed of 20 μm to 50 μm. If the opening is not circular or generally circular, the above size refers to its maximum width.

  An example of a possible embodiment for an elastic element to be used in a holder is shown in FIG. Each element 31, 32, 33 and 34 shown has portions 311, 312, 321, 322, 331, 332, 341, 342 that will be in contact with the getter pills, which are flat, Alternatively, it is rounded and suitable for achieving dispersed contact with the getter pill surface.

  FIG. 4 shows a plan view of a holder 40 including an elastic element 41 of one such elastic element. In FIG. 4, getter material pills 42, 42 '. . . Only one cover element of the holder is represented. Referring generally to the holder of the getter system of the present invention, generally speaking, the cover and bottom of the holder are each directed outwardly (cover) or directed to the inner part of the tube within the heat collection tube. Identify the parts of the getter system (bottom). Therefore, the cover and bottom refer to the geometrical arrangement and do not refer to the way in which the getter system is assembled, for example, in the embodiment shown in FIG. 4, the getter pill is on the part that is to become the cover. Be placed.

  An alternative embodiment of the getter system envisions the use of a modified perforated cover, which instead of providing a flat surface, a series of one or more indentations that coincide with the getter pills in the net. In order to achieve a distributed contact interface between the cover and the getter pill, such depressions are also rounded or provide a flat contact surface.

  A cross-section 50 of this configuration is schematically represented in FIG. 5, in which a pill made of compressed getter material 51 is placed on a flat holder bottom 52 and indented in a mesh 54 that is part of a perforated cover 55. 53 and 53 'are restrained in the vertical direction.

  Such a configuration also has the advantage of deterring pills with respect to vertical displacement.

  Further preferred embodiments envisage the use of both a recessed perforated cover and an elastic element to suppress pill displacement in all directions, but they can also be employed alone.

  As mentioned above, according to the present invention, the phenomena that result in the decomposition of the pill structure and hence the production of powder are minimized. Nevertheless, such a phenomenon always exists and has the property of gradually worsening over time as a result of the pill becoming fragile after hydrogen sorption, so it is particularly important to confine the powder effectively. It is preferred to provide a holder having a knitted mesh or net.

DESCRIPTION OF SYMBOLS 10 Getter system 11 Getter material pill 11 'Getter material pill 11 "Getter material pill 12 Bottom 13 Side shoulder 13' Side shoulder 14 Wire mesh 15 Element 15 'Locking element 20 Getter system 21 Getter material pill 21' Getter material Pill 21 "getter material pill 22 metal mesh 23 cover 24 tab 31 elastic element 32 elastic element 33 elastic element 34 elastic element 311 part 312 part 321 part 322 part 331 part 332 part 341 part 342 part 40 holder 41 elastic element 42 getter material pill 42 'getter material pill 50 cross section 51 getter material 52 holder bottom 53 indentation 53' indentation 54 net 55 perforated cover

[Document name] Description [Title of invention] Improvement of solar collector tube [Technical field]
[0001]
The present invention relates to improvements to solar collector tubes.
[Background]
[0002]
Solar collectors are becoming an increasingly important alternative energy source. In these devices, and more specifically in the solar collector tubes, the presence of hydrogen increases heat conduction from the central tubular body through which the heat removal fluid flows to the outside of the collector tube, and therefore its efficiency. The presence of hydrogen is harmful. Since the fluid flowing through the central tubular body tends to decompose at high temperatures and produce hydrogen, the problem with the presence of hydrogen is a particularly relevant problem in this case.
[0003]
Even in the new generation of collectors that utilize different fluid types to remove heat at higher temperatures, more hydrogen gas is released from the metal portion of the collector at such higher temperatures, so Problems related to existence and the resulting degradation of device characteristics are particularly problematic.
[0004]
There are additional problems associated with high internal temperatures in the heat collection tube that make the getter material unfavorable operating conditions with respect to hydrogen capacity, which is inversely proportional to the operating temperature.
[0005]
For this reason, several technical means as disclosed in Patent Document 1 have been developed. In Patent Document 1, a getter material is arranged in a heat collecting tube, and in order to efficiently accommodate the getter material, Describes a configuration that takes shape, the purpose of which is to shield the getter material from solar radiation and the part of the collector that reaches the highest temperature.
[0006]
This type of configuration usually has some disadvantages because a standard, i.e., 10 mm diameter, pill-shaped getter material consisting of compressed powder is utilized, which is sufficient in the heat collection tube. In order to introduce a quantity of getter material to ensure proper device operation over 20-30 years, all sleds imply that it will contain two pill lines, usually in each collector tube Accommodates two sleds.
[0007]
This causes two problems of different nature, on the one hand, the problem of greater difficulty in loading getter material in the form of two getter pill lines adjacent to each other, on the other hand, contacting each other, The problem is that the number of contact points of the pill that comes into contact with the sledge wall increases.
[0008]
These contact points selectively create areas that are fragile, resulting in a powder. The generation of powder and subsequent desorption from the pill is a phenomenon that should be minimized as much as possible even when the powder is confined by a suitable confined metal mesh. These detached powders cause problems not only in terms of aesthetics but also in terms of function (for example, the transparency of the surface exposed to radiation is degraded, resulting in a decrease in the thermal efficiency of the heat collection tube).
[Prior art documents]
[Patent Literature]
[0009]
[Patent Document 1] US Pat. No. 6,832,608 [Patent Document 2] US Pat. No. 3,320,901 [Patent Document 3] US Pat. No. 4,306,887 [Patent Document 4] British Patent No. 2077487 [Patent Document 5] US Pat. No. 5,961,750 [Patent Document 6] International Publication No. 2007/148362 [Patent Document 7] International Publication No. 2007/099575 [Patent Document 8] International Publication No. 2010/105945
[Patent Document 9] US Pat. No. 3,225,910
[Patent Document 10] US Patent Application Publication No. 2008/0272333
[Patent Document 11] US Patent Application Publication No. 2004/0056343 Summary of the Invention
[Problems to be solved by the invention]
[Means for Solving the Problems]
[0010]
The object of the present invention is to mitigate the severity of this phenomenon, and in its first aspect, the present invention comprises a solar heat collecting system comprising a getter system comprising a mechanical support and a pill of compressed powder of getter material. In the collector tube, the mechanical support comprises a holder consisting of a bottom and two lateral shoulders, the getter powder pill has a diameter of 15 mm or more, the diameter / height ratio consists of 2-5, The pills are characterized in that they are received in the holder at the bottom of the holder in a single line.
[0011]
Patent document 9 discloses an example of getter pills arranged in a single line, but that patent does not provide any size range for the pills, which may not contact each other, Used to maintain the vacuum in the tube.
[0012]
The previously referenced holder of the getter system can also be referred to as a U-shaped sled, and for the purposes of the present invention, the two terms have equivalent meanings.
[0013]
The invention is described below with the help of the following drawings.
[Brief description of the drawings]
[0014]
FIG. 1A is a side view of a first embodiment of a getter system to be used in a heat collection tube according to the present invention.
FIG. 1B is a plan view of a first embodiment of a getter system to be used in a heat collection tube according to the present invention.
FIG. 2A is a side view of an alternate embodiment of a getter system to be used in a heat collection tube according to the present invention.
2B is a plan view of an alternative embodiment of a getter system to be used in a heat collection tube according to the present invention. FIG.
FIG. 3 shows some possible embodiments for an elastic element to be used in a mechanical support.
4 is a plan view of a getter system to be used in a heat collecting tube that incorporates one of the elastic elements shown in FIG.
FIG. 5 is a cross-sectional view of another embodiment of a getter system to be used in a heat collection tube.
BEST MODE FOR CARRYING OUT THE INVENTION
[0015]
In the drawings, the dimensions and ratios of the elements are not limited, but are particularly accurate when referring to the dimensions of the metal mesh openings, and have been changed to make the illustration of the invention easier to understand. In addition, some optional elements such as, for example, an optional heat shield, or a securing means for the holder / sledge are not shown because they are not essential to understanding the present invention.
[0016]
According to the present invention, the operation of loading the getter material pill into its housing holder is greatly simplified.
[0017]
It should be understood that increasing the surface area of the getter material pill degrades the properties compared to a pill with a small surface area. Nevertheless, this degradation is compensated by the above-mentioned advantages that are specifically associated with the technical field, namely solar collector tubes.
[0018]
In fact, if the pill surface increases at the same height, it becomes fragile and difficult to handle as a result, while increasing the height will adversely affect the pumping speed and cause an increase in pill internals. There is a problem of encountering gaseous impurities when reaching the region. Therefore, those skilled in the art have not adopted such a solution due to the adverse effects expected when adopting a pill with an increased diameter. It should also be emphasized that the getter pills to be used in the present invention are obtained by appropriately compressing the powder of the getter material, so that they do not contain a binder. For example, it affected the capacity of the material, meaning the amount of hydrogen adsorbed by each pill. This is a fundamental aspect that affects pill structure resistance and related constraints for successful use in solar collector applications.
[0019]
Considering the reverse phenomenon described above, the optimum ratio of pill diameter to its height is 2-5, and for exactly the same reason, problems begin to appear for pills with diameters greater than 35 mm.
[0020]
Patent Document 10 discloses getter pills having a much wider range of diameter / height ratios, the ratios vary from 0.4 to 60, the diameter is as small as 2 mm, and the minimum pill height in this application. Is 3 mm, the height is as low as 0.5 mm, and these pills may contain a binder to increase their strength.
[0021]
U.S. Patent No. 6,057,031 discloses a single example of a getter pill having a diameter of about 20 mm and a diameter / height ratio of about 2.5, however, the pill is 5% by weight to manufacture, Requires 25% inorganic binder.
[0022]
Such pills are not suitable to meet the requirements of solar collectors, and the presence of the binder adversely affects its hydrogen sorption capacity .
[0023]
The pill diameter is preferably 18 mm to 25 mm, and the ratio of the diameter to the height is preferably 3 to 4. By operating with a pill loaded holder with such dimensional characteristics, by using only one holder / sled, a sufficient amount of getter material that can guarantee a device life of 20-30 years It can be inserted into the heat collecting tube. On the other hand, the currently utilized configuration assumes the use of two different holders for each heat collection tube, and not only the holder but also the element that completes the mechanical support, ie the confined metal mesh In addition to the structural costs of including spacers and appropriate heat shields, there are problems associated with positioning and securing.
[0024]
Also, the holder preferably has a width that is 1 to 3 mm wider than the pill diameter, which allows the pill to adapt to some extent within the holder, resulting in a pill structure as a result of hydrogen sorption by the getter material. Solve the technical problems associated with swelling.
[0025]
Further preferred embodiments that envisage the use of a wire mesh as the upper closure system for the holder, such as element 14 in FIG. 1B, with respect to the height of the holder, meaning the height of the elements that make up the side shoulders. Then, the height of the side shoulder is 0.5 mm to 1 mm lower than the pill height. This ensures that the net itself also acts as a deterrent element for the getter material pill, limiting its reciprocation, and the possibility that the pill will break as a result of collisions, thereby increasing powder production. To do.
[0026]
As in the case of element 23 shown in FIG. 2A, the shoulder height is 1 mm to 3 mm higher than the pill height for exactly the same reason, and for the above technical effect, if part of the upper closure system is rigid. It is preferable.
[0027]
In a further preferred embodiment, the holder also includes one or more elastic elements that are in direct contact with the one or more getter material pills.
[0028]
The main function of these elastic elements is to apply an appropriate compressive force to the pills so that the pills press against each other. This effect is due to the compression exerted by the elastic element causing the pill to move within the holder, even when the getter pill is larger than the size of the getter pill, its most useful representation being contained within the sled. prevent.
[0029]
If the pressure value is excessive, the pill structure will be destroyed instead of preventing the pill from moving in the holder, so the applied pressure value is an important parameter. Strictly speaking, it depends on the application field and is specifically related. The determination of such values is further made difficult by the fact that it takes into account the expansion of the pill as a result of hydrogen sorption by the getter material and the increased pill structure vulnerability as a result of hydrogen sorption. The inventor has found that the compressive force applied by the elastic means should be between 50N and 150N. This value was examined and measured in a newly introduced getter system and therefore when the getter material pill can be considered "new", i.e., it has adsorbed only a minimal amount of hydrogen.
[0030]
Furthermore, in order to avoid having selective powder production spots, the elastic elements should be free of angular corners in the contact area with the getter material pill, so that these elastic elements are not in contact with such In place, it should give a flat or rounded surface. Such a feature is hereinafter referred to as “dispersed contact”.
[0031]
As for the getter material, a material showing a good hydrogen sorption capacity is preferable even when used at a high temperature.
[0032]
Therefore, preferred getter materials useful for the present invention include Patent Document 2 (Zr—Al alloy), Patent Document 3 (Zr—Fe alloy), Patent Document 4 (Zr—V—Fe alloy), and Patent Document 5 (Zr). -Co-rare earth alloys). For example, the use of yttrium alloys is also known, particularly for hydrogen sorption at high temperatures, as described in US Pat. Nos. 6,099,575 and 2010/105945. While the above getter alloys are preferred materials for use with the present invention, any hydrogen getter material can be utilized with the disclosed inventive concepts. Furthermore, it can be envisaged to use pills formed with several different getter materials, or the holder can be loaded with different types of pills.
[0033]
1A and 1B show a first embodiment for a getter system 10 for a solar collector tube, where the pills 11, 11 ', 11 "... of the getter material are of the holder. Aligned on the flat bottom 12, there is a confining wire mesh 14 and is fixed to the holder, for example by electric welding.
[0034]
In the configuration shown in FIG. 1, there is also an optional element 15, which acts as a stopper and operates mechanically when the pill is loaded into the holder. FIG. 1A shows only one of such elements 15 near one of the holder ends, but the second end also has a second locking element as shown in FIG. 1B. There can be 15 ′.
[0035]
The wire mesh can be fixed to the holder in various ways, for example it can be fixed on the holder lateral shoulder 13, 13 'or it can be wrapped on the outer surface of the holder and fixed at the flat bottom 12. be able to. In this second case, according to a preferred fixing configuration, the edges of the mesh 14 are slightly overlapped and then a single electric weld is performed to fix the mesh 14 to the holder.
[0036]
As shown in FIGS. 1A and 1B, the wire mesh is arranged not to cover the entire length of the holder in order to avoid interfering with the feasible means needed to secure the holder in the heat collecting tube. So that the end can be left open.
[0037]
2A and 2B show an alternative embodiment, where the getter system 20 includes getter material pills 21, 21 ′, 21 ″... Disposed at the bottom of the holder structure, the structure being It is closed by a cover 23 including an opening, and a metal mesh 22 is disposed in the opening.
[0038]
Thereafter, although not shown, the cover 23 is fixed to the holder bottom by an appropriate fixing means such as a clew, for example.
[0039]
In FIG. 2A there are also several tabs 24 that are folded to serve as stoppers for the getter material pills 21, 21 ′, 21 ″.
[0040]
This configuration allows for the production of a closed holder structure with a semi-finished holder cover on which a metal mesh is secured, thus simplifying the assembly of the getter system used in the present invention. Have advantages.
[0041]
Also in the second embodiment, in a preferred implementation, the width of the holder is slightly wider relative to the pill diameter and its side shoulder height is slightly lower than the pill height. Also, in this case, it is assumed that a preferable dimension is to use a holder having a width that is 1 mm to 3 mm wider than the pill diameter and a side shoulder height that is 0.5 mm to 1 mm lower than the pill height. In this embodiment, the pill stopper 24 also serves the purpose of applying a slight longitudinal pressure on the pill line, thereby restricting the pill from moving laterally.
[0042]
As far as the properties of the wire mesh used in the system according to the invention, such as the wire mesh represented in FIGS. Holes, more generally gaps. The wire mesh opening is preferably composed of 20 μm to 50 μm. If the opening is not circular or generally circular, the above size refers to its maximum width.
[0043]
An example of a possible embodiment for an elastic element to be used in a holder is shown in FIG. Each element 31, 32, 33 and 34 shown has portions 311, 312, 321, 322, 331, 332, 341, 342 that will be in contact with the getter pills, which are flat, Alternatively, it is rounded and suitable for achieving dispersed contact with the getter pill surface.
[0044]
FIG. 4 shows a plan view of a holder 40 including an elastic element 41 of one such elastic element. In FIG. 4, getter material pills 42, 42 '. . . Only one cover element of the holder is represented. Referring generally to the holder of the getter system of the present invention, generally speaking, the cover and bottom of the holder are each directed outwardly (cover) or directed to the inner part of the tube within the heat collection tube. Identify the parts of the getter system (bottom). Therefore, the cover and bottom refer to the geometrical arrangement and do not refer to the way in which the getter system is assembled, for example, in the embodiment shown in FIG. 4, the getter pill is on the part that is to become the cover. Be placed.
[0045]
An alternative embodiment of the getter system envisions the use of a modified perforated cover, which instead of providing a flat surface, a series of one or more indentations that coincide with the getter pills in the net. In order to achieve a distributed contact interface between the cover and the getter pill, such depressions are also rounded or provide a flat contact surface.
[0046]
A cross-section 50 of this configuration is schematically represented in FIG. 5, in which a pill made of compressed getter material 51 is placed on a flat holder bottom 52 and indented in a mesh 54 that is part of a perforated cover 55. 53 and 53 'are restrained in the vertical direction.
[0047]
Such a configuration also has the advantage of deterring pills with respect to vertical displacement.
[0048]
Further preferred embodiments envisage the use of both a recessed perforated cover and an elastic element to suppress pill displacement in all directions, but they can also be employed alone.
[0049]
As mentioned above, according to the present invention, the phenomena that result in the decomposition of the pill structure and hence the production of powder are minimized. Nevertheless, such a phenomenon always exists and has the property of gradually worsening over time as a result of the pill becoming fragile after hydrogen sorption, so it is particularly important to confine the powder effectively. It is preferred to provide a holder having a knitted mesh or net.
[Explanation of symbols]
[0050]
DESCRIPTION OF SYMBOLS 10 Getter system 11 Getter material pill 11 'Getter material pill 11 "Getter material pill 12 Bottom 13 Side shoulder 13' Side shoulder 14 Wire mesh 15 Element 15 'Locking element 20 Getter system 21 Getter material pill 21' Getter material Pill 21 "getter material pill 22 metal mesh 23 cover 24 tab 31 elastic element 32 elastic element 33 elastic element 34 elastic element 311 part 312 part 321 part 322 part 331 part 332 part 341 part 342 part 40 holder 41 elastic element 42 getter material pill 42 'Getter material pill 50 Cross section 51 Getter material 52 Holder bottom 53 Recess 53' Recess 54 Net 55 Perforated cover

Claims (17)

  A solar collector collector tube containing a getter system (10; 20) comprising a mechanical support and pills (11, 21, 51) made of compressed powder of getter material, the mechanical support being Including a holder consisting of a bottom (12) and two lateral shoulders (13, 13 '), the getter powder pill (11, 21) having a diameter of 15 mm or more and a diameter / height ratio of 2-5 And a solar collector tube containing a getter system, characterized in that it is housed in the holder at the bottom (12) in a single line.   The heat collecting tube according to claim 1, wherein the diameter of the getter powder pill (11, 21, 51) is 35 mm or less.   The heat collecting tube according to claim 2, wherein the diameter is 18 mm to 25 mm.   The heat collecting tube according to claim 1, wherein the diameter / height ratio is 3 to 4.   The holder further comprises one or more elastic elements (31, 32, 33, 34) in contact with one or more of the getter powder pills (11, 21, 51), the elastic elements comprising: 2. A heat collecting tube according to claim 1, characterized in that it provides a flat or rounded part (311, 312; 321, 322; 331, 332; 341, 342) for contact with the getter powder pill. .   The heat collecting tube according to claim 5, wherein the elastic element (31, 32, 33, 34) applies a compressive force of 50 N to 150 N on a new getter pill.   The heat collection tube according to any one of claims 1 to 6, wherein the holder is partially wrapped by a wire mesh.   The heat collecting tube according to claim 7, wherein the wire mesh has an opening having a diameter of 10 μm to 500 μm.   The heat collecting tube according to claim 8, wherein the diameter is 20 μm to 50 μm.   The heat collecting tube according to any one of claims 7 to 9, wherein the wire mesh is fixed on the side shoulder (13, 13 ') of the holder.   The heat collecting tube according to any one of claims 7 to 9, wherein the wire mesh is fixed to the outside of the bottom (12) of the holder.   The heat collecting tube according to any one of claims 7 to 9, characterized in that the wire mesh (14) partially overlaps and is fixed to the outside of the bottom (12) of the holder in the overlapping region. .   The holder has a width wider than a diameter of the getter powder pill (11, 21, 51), and a difference between the width of the holder and the diameter is 1 mm to 3 mm. The heat collecting tube according to any one of 1 to 12.   The height of the side shoulder (13, 13 ′) of the holder is less than the height of the getter powder pill (11, 21, 51), and the height of the side shoulder (13, 13 ′) 14. The heat collecting tube according to claim 1, wherein the difference between the height of the getter powder pills (11, 21, 51) is between 0.5 mm and 1 mm.   The holder is closed by a perforated cover (23) having a wire mesh (22) in the opening of the cover, and the height of the side shoulders (13, 13 ') is 1 to 3 mm higher than the getter powder pill. The heat collecting tube according to any one of claims 1 to 6, wherein the heat collecting tube is provided.   The heat collecting tube according to claim 15, wherein the wire mesh has an opening having a diameter of 10 μm to 500 μm.   16. The perforated cover (55) provides one or more indentations (53, 53 ') to achieve distributed contact with the getter powder pill (11, 21, 51). The heat collecting tube as described.

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