THERMAL DERIVATIVE OF AN AIRFLOW

Abstract

Existing devices, which divert an airflow when said airflow reaches a predetermined temperature, use expensive materials and automation such as, for example, stainless materials (steel, anodized aluminum, synthetic materials), electronic temperature sensors, and mechanisms for opening and closing air ducts. The device (the object of the invention) diverts (1) an airflow (3) based on its temperature and solves this cost problem by primarily using hollow concrete blocks (2) or hollow clay bricks as components, the costs of which are greatly reduced because concrete blocks and bricks are very commonly used materials in masonry. Figure for the Abstract: [Fig. 2]

Description

Title of the invention: THERMAL DERIVATIVE OF AN AIR FLOW Technical field of the invention

[0001] The invention relates to a mechanical device that allows an airflow to be diverted in one direction or another depending on its temperature. Technical background

[0002] A thermal bimetallic strip is composed of two superimposed and bonded metal strips with different coefficients of thermal expansion. As a result, a temperature variation causes a difference in the expansion of each of the two strips, causing a curvature of the bimetallic strip that is proportional to this temperature variation. This curvature is used in many fields, particularly electrical ones, to create or break contact between two conductors, thereby creating or stopping the flow of an electric current when the current intensity, responsible for overheating, becomes too high. The variation in curvature of a thermal bimetallic strip is also used to decrease or increase the flow rate of a hot air stream in order to regulate the temperature of an air duct (CN210979907 (U) — 2020-07-10).A thermal bimetallic strip is robust, reliable, and relatively inexpensive; these are strong arguments for using it instead of more sophisticated devices based on electronic thermal sensors or electromechanical automation. However, when a thermal bimetallic strip needs to be used in large numbers, for example, to divert a large number of airflows either to a first duct or to a second duct, depending on the airflow temperature, then the cost of the materials used to enable this functionality represents a significant factor in the overall project cost. Generally, the materials used for ducts are metallic or synthetic, and they must withstand significant temperature variations as well as weathering. Presentation of the invention

[0003] The object of the invention is to describe a device comprising an air inlet, a first air outlet, a second air outlet and a thermal bimetallic strip capable of deforming under the influence of the temperature of the incoming air, so that the incoming air is directed towards the first outlet or towards the second outlet, depending on the temperature of the incoming air which will be higher or lower than a chosen value; said device then has the particularity of being less expensive than existing devices and being just as robust. Summary of the invention

[0004] In its basic version, the device (1) of this invention is capable of diverting an airflow (3) when said airflow (3) reaches a chosen temperature T0; said diverting device (1) comprises:

[0005] - a bypass chamber (2) comprising at least three openings A, B and C, Opening A is traversed by said incoming airflow (3) which enters the bypass chamber (2), opening B is traversed by said incoming airflow (3) which exits the bypass chamber (2) when its temperature is greater than T0, opening C is traversed by said incoming airflow (3) which exits the bypass chamber (2) when its temperature is less than T0,

[0006] - a thermal bimetallic strip (4) positioned inside said bypass chamber (2), said bimetallic strip (4) is in contact with the incoming airflow (3) and is capable of bending under the effect of a temperature variation of the incoming air (3); said thermal bimetallic strip (4) is capable, by means of its deformation, either of closing the opening B to allow the incoming airflow (3) to exit through the opening C; or of closing the opening C to allow the incoming airflow (3) to exit through the opening B.

[0007] said bypass device (1) is characterized in that said bypass chamber (2) is part of one of the cavities of a hollow block, or hollow brick, commonly used in masonry and in which block, or hollow brick, the openings A, B and C have been drilled.

[0008] The concrete block is one of the most widely used building materials in masonry, due in particular to its good value for money and ease of installation. The concrete block is a hollow material with a porous structure, shaped like a parallelepiped, used for the construction of walls and buildings. It forms the framework of structures. The dimensions of a standard concrete block are approximately 20 cm long, 50 cm wide, and 25 cm high. The thickness of the concrete block varies depending on its intended use. The bypass chamber (2) that is the subject of the invention preferably requires two closely spaced parallel faces because each of the openings B and C is made on opposite faces of the concrete block, which must be able to be sealed by the surface of the thermal bimetallic strip when it bends under the effect of heat.The surface of the thermal bimetallic strip can only bend by one to two centimeters when its length is around 20 cm; this is why it is advantageous to choose a concrete block whose internal cavities have parallel surfaces spaced only one to two centimeters apart. There are several main types of concrete blocks.

[0009] Hollow concrete block: The hollow concrete block is the most common type of concrete block. It is used to build simple walls. Its distinguishing feature is its honeycomb structure and hollow ends, which facilitate jointing. Hollow concrete blocks can be cut to one-third or two-thirds of their length for use.

[0010] Corner block: also called a "column block," the corner block is hollow but also has a hole, square or round, and flat ends. It is perforated to receive the vertical reinforcement of a wall, composed of steel strands, which serves to stiffen the structure. The corner block can be cut to one-third of its length.

[0011] The lintel block: this block is hollowed in the shape of a "U" to be able to receive a lintel or the horizontal tie beam of a building.

[0012] Jamb block: this type of block is used for making corners or frames of window or door openings.

[0013] The solid (or perforated) concrete block: this is a heavy and dense concrete block, particularly intended for the construction of building foundations and basements. The solid concrete block provides great strength to constructions.

[0014] The interlocking concrete block: the interlocking block is an "H"-shaped concrete block used to construct retaining walls. Equipped with cavities, the concrete is poured directly into the block.

[0015] The "planelle" concrete block: this small, thin concrete block is intended to be placed at the intersections of floors and masonry to conceal the floor edges and tie beams. This is the one chosen as the primary choice for creating the aforementioned bypass device (1) because some models have internal cavities that are only about fifteen millimeters wide.

[0016] Concrete blocks are an inexpensive material. Composed primarily of natural materials, concrete blocks are 100% recyclable. When bonded together with mortar (a mixture of cement, sand, and water), concrete blocks allow for the rapid and easy construction of buildings. Ordinary concrete blocks are made of cement, gravel, sand, and crushed stone. Other concrete blocks also incorporate insulating materials such as expanded clay, shale, or pumice stone, while yet another type of concrete block is made of silica sand, plaster, aluminum powder, or lime.

[0017] Another option is to choose a hollow brick instead of a hollow concrete block. The hollow brick is made of clay soil and is rectangular in shape. However, the dimensions of the internal cavities are less suitable for manufacturing the bypass device (1) than those of the "planelle" concrete blocks. Indeed, the "planelle" concrete blocks have four or five identical cavities that can be used as bypass chambers (2a, 2b, 2c, 2d, 2e); thus, with a single "planelle" type concrete block (D) and by positioning a thermal bimetallic strip (4a, 4b, 4c, 4d, 4e) in each of the chambers and by making the openings A1, A2, A3, A4; A5... Bl, B2, B3, B4, B5... and Cl, C2, C3, C4, C5... it is easy to manufacture four or five devices (1) capable of diverting an airflow (3) when this said airflow (3) reaches a chosen temperature T0.

[0018] In all cases, the diversion of the incoming airflow (3) through opening A and the outgoing airflow towards outlet B or outlet C occurs at a temperature respectively higher or lower than the chosen T0, but with an approximation that can be 5 to 10°C depending on the technology of the thermal bimetallic strip itself and its hysteresis; the value of T0 can then take the following values: 30°C, 40°C, 50°C, 60°C, 70°C, 80°C, 90°C, 100°C, 110°C. The curvature of said bimetallic strip (4) depends on its thermomechanical characteristics, including in particular: its length, its thickness, and the choice of the different materials that constitute each of its two strips.

[0019] In a particular embodiment, the device (1), capable of diverting an airflow (3) when said airflow (3) reaches a chosen temperature T0, is coupled to a device for heating the ambient air before its introduction into said device (1). The opening (A) is traversed, for example, by an incoming airflow (3) that has been previously heated by means of solar energy, such as by means of vacuum solar tubes exposed to solar radiation; the fluctuation of the solar intensity consequently causes a fluctuation in the temperature of the airflow (3) entering said diverting chamber (2). Said device (1) is then capable of diverting the solar-heated airflow either to outlet B or to outlet C, depending on the chosen temperature T0.It is then possible to heat a dwelling or part of it, only when a minimum amount of solar energy is available; this increases the performance and energy balance of the heating system.

[0020] In an improved embodiment, said hollow block (D) is composed of two hollow blocks ([Fig.3]: PI, P2), preferably of the "planelle" type, placed one on top of the other on edge, so as to double the volume of each cavity by positioning each of the cavities of one of the blocks opposite the corresponding cavities of the other block, said blocks being able to be replaced by hollow bricks. This arrangement allows the height of the bypass chambers (2a, 2b, 2c, 2d, 2e) to be increased and thus allows the length of the bimetallic strips (4a, 4b, 4c, 4d, 4e) to be increased, which will increase the curvature at the time of temperature rise, which will facilitate and improve the opening and closing of the openings (B1,B2,B3,B4,B5) and (C1,C2,C3,C4,C5). Detailed description of the invention

[0021] The invention is now described in more detail with reference to the three attached figures:

[0022] Figures 1 and 2 are schematic diagrams in cross-section of the device (1) and [Fig.3] is a schematic diagram of the device (1) when it uses a block (D) of the "planelle" type for its manufacture.

[0023] [Fig. 1] shows in cross-section a device (1) according to the invention which is capable of diverting an airflow (3) entering through the opening (A) and directing it (5) towards the opening (C) or directing it (6) towards the opening (B). The device (1) comprises a diverting chamber (2) which includes at least three openings (A, B, and C). The opening (A) is the one that receives the incoming airflow (3), which can be diverted either towards the opening (C) or towards the opening (B). A thermal bimetallic strip (4) is capable of deforming, and more specifically of bending along its length, in a manner substantially proportional to its temperature. At a predefined temperature (T0), or at a lower temperature, the bimetallic strip (4) is substantially flat and closes the opening (B) so that the incoming airflow (3) exits through the opening (C).

[0024] [Fig.2] shows the device (1) when the temperature of the incoming airflow (3) is su greater than the reference (T0). In this case, the bimetallic strip (4), in contact with the incoming air (3), heats up and expands, forming an arc that progressively opens the opening (B) and progressively closes the opening (C). The hot air (6) then exits through the opening (B).

[0025] [Fig.3] represents a concrete block (D) which is composed of two concrete blocks of type " The planelle ([Fig. 3]: P1 and P2) are placed edge-on on top of each other, forming five independent and identical cavities ([Fig. 3]: 2a, 2b, 2c, 2d, 2e) which serve as bypass chambers. In each of these chambers, three openings have been drilled ([Fig. 3]: A1...A5, B1...B5 and C1...C5) and five identical bimetallic strips ([Fig. 3]: 4a, 4b, 4c, 4d, 4e) are attached so that each cavity ([Fig. 3]: 2a, 2b, 2c, 2d, 2e) is capable of diverting an incoming airflow ([Fig. 3]: 3a, 3b, 3c, 3d, 3e): either towards the corresponding outlet ([Fig. 3]: B1, B2, B3, B4, B5) or towards the outlet ([Fig.3] : Cl, C2, C3, C4, C5) corresponding, as a function of the reference temperature (T0) (which is a characteristic of said thermal bimetallic strips 4a, 4b 4c, 4d, 4e and the corresponding temperature T1, T2, T3, T4, T5 of each of the incoming airflows 3a, 3b, 3c, 3d 3e. Ultimately a single block ([Fig.3] : D) according to the invention (possibly formed of two "planelle" type blocks) is capable of individually directing five independent airflows according to their respective temperature, without electronic sensor, without remote control valve, without electrical connection; and at a very low cost which amounts to that of one or two blocks commonly used in masonry, five low-priced thermal bimetallic strips, and the cost which was required to drill about fifteen holes in said block ([Fig.3] : D). . Examples

[0026] An example of an embodiment of a device using this technique is schematically illustrated in [Fig. 3] and comprises a concrete block ([Fig. 3]: D) composed of two hollow concrete blocks of the "planelle" type ([Fig. 3]: P1 and P2) which are placed one on top of the other to form five watertight bypass chambers ([Fig.3]: 2a, 2b, ... 2e). Then, five circular openings ([Fig.3]: A1, A2, ... A5) were cut into one face of the upper concrete block ([Fig.3]: PI); these five openings communicate with each of the bypass chambers ([Fig.3]: 2a, 2b, ... 2e). Five pairs of openings positioned opposite each other ([Fig.3]: (B1, C1) (B2, C2) ... (B5, C5)) were cut into the two faces of the lower concrete block ([Fig.3]: P2); these five pairs of openings communicate with each of the bypass chambers ([Fig.3]: 2a, ... 2e). A rectangular thermal bimetallic strip ([Fig.3]: 4a, 4b, ... 4e) is fixed in each of the bypass chambers ([Fig.3]: 2a, 2b, ... 2e) in a vertical position so that, at ambient temperature, said bimetallic strips block the openings ([Fig.3]: B1, B2, ... B5). But during the curvature of the bimetallic strips which increases under the effect of the temperature of the air flows ([Fig.3]: 3a, 3b, ... 3e) entering through the openings ([Fig.3]: A1....A5); the openings ([Fig.3]: B1...B5) open slightly while the openings ([Fig.3]: C1...C5) close.

[0027] Each hollow concrete block ([Fig. 3]: P1 and P2) is 50 cm long externally, 20 cm high, and 5 cm thick. The walls of the blocks are 16 mm thick, and the interior of the bypass chambers is 18 mm wide and 35 cm high. The openings at the top ([Fig. 3]: A1...A5) are 62 mm in diameter, allowing one end of the 57 mm diameter cylindrical vacuum solar tubes (not shown) to enter the bypass chambers ([Fig. 3]: 2a...2e) to circulate air heated by solar radiation. The pairs of openings at the bottom are 32 mm in diameter. The thermal bimetallic strips are 5 cm wide, 0.8 mm thick, and 17 cm long. The bimetallic strips are positioned between the pairs of openings at the bottom ([Fig.3] : (B1,C1) ...(B5,C5)) so that the center of the bimetallic strips is at the same height (opposite) as the center of the pairs of openings at the bottom.

[0028] Vacuum solar tubes (not shown) supply air to the bypass chambers. The air temperature in the solar tubes depends on the amount of sunlight and the airflow rate. It can vary from ambient temperature up to 150°C. The thermal bimetallic strips begin to bend at a temperature of approximately 40°C, and the air that was passing through the openings ([Fig. 3]: C1...C5) then begins to gradually pass through the openings ([Fig. 3]: B1...B5). At around 60°C, the bimetallic strips are sufficiently bent to obstruct the openings ([Fig. 3]: C1...C5) and to allow air to pass through the openings ([Fig. 3]: B1...B5). The hot air that passes through all these openings ([Fig.3]: B1...B5) is then recovered in a pipe (not shown) and directed to a specific application such as, for example, an atmospheric water generator. ADVANTAGES OF THE INVENTION

[0029] Ultimately, this invention, which aims to minimize the cost of "airflow diverter-type devices based on their temperature", primarily uses Hollow concrete blocks (already widely used in masonry) are used as the material for constructing the bypass chambers. This significantly reduces the cost of devices based on this invention, especially when a large number of such devices are required for large-scale solar heating programs.

Claims

Demands

1. - Device (1) capable of diverting an airflow (3) when said airflow (3) reaches a chosen temperature (TO); said diverting device (1) comprises: - a diverting chamber (2) which includes at least three openings (A, B and C); the opening (A) is traversed by said incoming airflow (3) which enters the bypass chamber (2), the opening (B) is traversed by said incoming airflow (3) which exits the bypass chamber (2) when its temperature is greater than (TO), the opening (C) is traversed by said incoming airflow (3) which exits the bypass chamber (2) when its temperature is less than (TO), - a thermal bimetallic strip (4) positioned inside said bypass chamber (2), said thermal bimetallic strip (4) is in contact with the incoming airflow (3) and is capable of bending under the effect of a temperature variation of the incoming air (3);said thermal bimetallic strip (4) is capable, by means of its deformation, either of closing the opening (B) to allow the incoming airflow (3) to exit through the opening (C); or of closing the opening (C) to allow the incoming airflow (3) to exit through the opening (B), said device (1) is characterized in that said bypass chamber (2) is part of one of the cavities of a hollow block (Figure 3: D), or of a hollow brick, commonly used in masonry and in which block or which brick have been pierced the said openings (A, B and C);

2. - Device (1) capable of diverting an airflow (3) when said airflow (3) reaches a chosen temperature (TO), according to the preceding claim 1, characterized in that said hollow block (Figure 3: D) comprises four or five cavities used as diverting chambers (Figure 3: 2a, 2b, 2c, 2d, 2e); each of the diverting chambers (Figure 3: 2a, 2b, 2c, 2d, 2e) comprises a thermal bimetallic strip (Figure 3: 4a, 4b, 4c, 4d, 4e) and three openings (Figure 3: (Al, A2, A3, A4, A5), (Bl, B2, B3, B4, B5) and (Cl, C2, C3, C4, C5)).

3. - Device (1) capable of diverting an airflow (3) when said airflow (3) reaches a temperature (TO) chosen according to one of the preceding claims, characterized in that the diversion of the airflow entering (3) through the opening (A) and exiting towards the outlet (B) or towards the outlet (C) takes place at a chosen temperature (TO) which is approximate and is at choice: 30°C, 40°C, 50°C, 60°C, 70°C, 80°C, 90°C, 100°C, 110°C; this airflow diversion is achieved by means of the deformation of said thermal bimetallic strip (4) and its thermomechanical characteristics including in particular: its length, its thickness and the choice of the different materials constituting each of its two strips.

4. - Device (1) capable of diverting an airflow (3) when said airflow (3) reaches a temperature (TO) chosen according to one of the preceding claims, characterized in that the opening (A) is traversed by an incoming airflow (3) which has been previously heated by means of solar energy, such as for example by means of vacuum solar tubes (not illustrated) exposed to solar radiation; the fluctuation of the solar intensity causing a fluctuation in the temperature of the airflow (3) which enters said diverting chamber (2).

5. - Device (1) capable of diverting an airflow (3) when said airflow (3) reaches a chosen temperature (TO), according to one of the preceding claims, characterized in that said hollow block (Figure 3: D) is composed of two hollow blocks (Figure 3: PI and P2) placed one on top of the other by their edges, so as to double the volume of each cavity by positioning each of the cavities of one of the blocks (Figure 3: PI) opposite the corresponding cavities of the other block (Figure 3: P2), said blocks (Figure 3: (PI, P2)) being able to be replaced by hollow bricks.

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