DE8805225U1 - Thermally controllable shut-off device in pipelines for gaseous flow media - Google Patents

Description

PATENT ENGINEER* ^: "· '· '· '**>· *..*\." Dipl.-Landw. P. Thielmann·!.· *..'*.."

ßuropean }2atent dLitotmy, 7

Am Eschanbero 14 - Tel. CO64613 2733 D-356O B I &Egr; DENKOPF / LAHN

03 IZ Rathgeber

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APPLICANT

Friedrich Rathgeber KG, Industriestrasse , ,, D-6349 Mittenaar 2, Austria

TITLE

Thermally controllable shut-off device in pipelines for gaseous flow media

DESCRIPTION

The invention relates to a thermally controllable shut-off device in pipelines for gaseous flow media, in particular in air conditioning and heating systems, exhaust air and flue gas pipes, wherein a movable flap or several movable, interacting flap wings are arranged as a shut-off device in a pipe section.

Such shut-off devices are already in use in various designs for various purposes and are therefore generally known. Depending on the area of application, there are devices that close a pipeline when the medium flowing through it cools down and those that close the pipeline when the flow medium suddenly heats up.

In heating systems with discontinuously operating oil or gas burners, for example, a shut-off device is used in the exhaust pipe behind or above the stove, which opens the exhaust pipe before the burner is ignited and closes it again after the burner is switched off. This prevents unnecessary heat from flowing out through the open exhaust pipe and being lost during combustion breaks.

For example, designs of shut-off devices are known for this purpose, in which a shut-off flap, the outline of which corresponds to the cross-section of the exhaust pipe, is arranged in the exhaust pipe on a flap shaft that is rotatably mounted in the pipe wall perpendicular to the pipe axis. An electric motor or magnet controlled in conjunction with the burner acts on the flap shaft.

Such shut-off devices are structurally complex and therefore relatively expensive. Designs in which the shut-off flap is operated by an electric motor depend for their operational reliability on the electric motor, which is subject to a certain amount of wear and tear, and are therefore not completely operational.

Thermally controlled exhaust flaps are also known, especially for gas heating systems, in which the shut-off device is formed by several flaps made of bimetal sheet metal cuts that are fastened to a pipe section arranged in the exhaust pipe. Such shut-off devices are required by official regulations if several gas heating systems are connected to a chimney. This is to prevent exhaust gases from entering the system.

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Heating devices that are not in operation can enter the rooms in question. The shut-off devices must not have any joints, shafts or bearings. These shut-off devices have the advantage that they are very simple in their construction and reliable in operation.

But they also have disadvantages: Apart from the fact that the flap wings made of bimetal sheet metal are expensive components, they have the disadvantage that they react relatively slowly. When the gas flame is ignited, the exhaust pipe should be opened as quickly as possible. To prevent a blockage in the exhaust pipe until the shut-off device is opened, the exhaust pipe must not be completely closed during the combustion breaks. At the same time, design measures must be taken to ensure that the flap wings are washed by the hot exhaust gases as quickly and intensively as possible. To achieve this, they are provided with slot-shaped openings.

These features therefore have a negative impact on the effectiveness in practical use on the one hand and on the price of such shut-off devices on the other.

The invention is therefore based on the task of improving a shut-off device with the features mentioned in the preamble of claim 1 and at the beginning of the description so that the disadvantages described are eliminated. The actuating element should carry out the closing or opening movements of the shut-off flap or flap wings as quickly as possible. It should be reliable in operation, but also simple in construction and inexpensive to manufacture.

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The stated object is achieved according to the invention in that at least one memory metal coil held at a fixed point is provided as the actuating element for the shut-off flap or flap wing, to which a controllable heat source is assigned or which is arranged in the media flow of the pipeline, the movable end of which is non-positively connected to the shut-off flap or the flap wing and which, when contracted as a result of heating, actuates the shut-off flap or the flap wing against the effect of at least one return spring.

Further details of the invention as well as alternative solutions are set out in claims 2 to 11.

_t « The invention is described below with reference to a

drawing showing several embodiments

explained in more detail. They show:

Fig. 1 A shut-off device in the exhaust pipe of a burner furnace, closing during burner breaks, in a perspective view;

Fig. 2 a) axial section through another embodiment of a shut-off device for gas heating devices that closes during burner breaks, with the "closed" position shown in solid lines and the "open" position shown in dashed lines; Fig. 3 a view of the same shut-off device from

view A according to Fig. 2;

Fig. 4 a shut-off device in a pipe which closes when heated in perspective

Representation with partial cross-section;

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Fig. 5 an axial section through another embodiment

Example of a shut-off device that closes when heated, with the "open" position shown in solid lines and the "closed" position shown in dashed lines;

Fig. 6 a view of the same shut-off device

from the Sicnt B gern4 FIg* 5.

In the embodiments explained here, a memory metal 1-^ coil is used, which
low temperature without significant resistance
can be stretched out within this low temperature range without springback effect in stretched form
Remains, but within seconds against considerable
Resistance contracts when it is reduced to a |

certain temperature and remains in the contracted form until its temperature is again

falls below the specified value. I

The embodiment shown in Fig. 1 is a shut -off device in the exhaust pipe of an oil burner. |

In a square pipe section 1, in itself j

In a known manner _, a shut-off flap 2 is attached to a flap shaft 3 running perpendicularly to the pipe axis and is rotatably mounted with the shaft in the pipe wall. |

At one end of the valve shaft 3 protruding from the top or side of the pipe section 1 ^k there is a
Double crank 4 in the form of a disc, which
two opposite crank pins 5, 6. The movable end of a
Memory metal coil 8, while the other
Crank pin 6 one at another fixed point 9

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held return spring iO in the form of a spiral tension spring attack *

In the immediate vicinity of the memory metal coil 8, in the area of its end held at the fixed point 7, there is a heat source controlled as a function of the electrical burner control, which in this case is an electrical resistor 11* which is arranged on a control panel 13 fastened to the pipe section 1 and surrounded by a removable housing 12. A transformer is also provided on the control panel 13, the primary side of which is connected to the electrical control of the burner via a power line 15. The resistor 11 is connected to the secondary side of the transformer 13 with a fuse 16 in between.

When the burner ignition process is initiated, the resistor 11 receives current and heats up. Under the effect of the heat radiated by the resistor 11, the memory metal coil 8 contracts and thereby turns the locking flap 2 in the direction of the pipe axis, i.e. into the "open" position, against the effect of the return spring 10 via the double crank 4.

As soon as the burner is switched off and the power supply to the resistor 11 is interrupted, the memory metal coil S cools down. It now stretches again under the action of the return spring 10, whereby the locking flap 2 is also turned by the return spring via the crank pin 6 transversely to the pipe axis and thus into the "closed" position, in which it remains until the next burner ignition. This prevents warm air from escaping from the furnace through the exhaust pipe.

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The example shown in Fig. 2 and 3 is a much simpler shut-off device in terms of its construction, particularly for ias heating systems. The shut-off device is formed by two interacting flap wings 22 made of spring sheet metal. These are fastened in a wing-like manner together with their base edge 22a to a web 23 arranged in the middle of a pipe section 1 transversely to the pipe section and parallel to the pipe axis so that they lie against one another in the "open" position in the direction of the pipe axis.

The flap wings 22 are each curved outwards starting from their base edge 22ä and cut so that their outer edge 22b rests against the inner wall of the pipe section 1 in the "closed" position.

The two flap wings 22 are connected to one another by a memory metal coil 8, the ends of which engage in the outer edge area of a flap wing. The flap wings 22 each have a recess 24, 25 in the middle edge area in the form of a radially extending wide slot which extends close to the outer edge 22b of the flap wing 22.

A holding arm 26, 27 protruding from the plane of the flap wing 22 on its concave side is arranged on the outer edge of each of the recesses 24, 25. The ends of a memory metal1 coil 8 running within the recesses 24, 25 across the connecting web 23 of the flap wings 22 are attached to their ends.

As soon as the hot exhaust gases from the newly ignited gas burner reach the memory metal coil 8, it contracts within seconds and opens

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so that the flap wings 22 move against their own spring force towards the "closed" position. After the gas flame has gone out, the memory metal coil 8 cools down and stretches under the spring force of the flap wings 22 without significant resistance, so that they can spring back into the "closed" position.

The embodiment shown in Fig. 4 is a shut-off device suitable for ventilation pipes - for example in cooker hoods - which must close immediately in the event of a sudden increase in temperature in the pipe, e.g. in the event of a fire. In a pipe section 1, as in the embodiment according to Fig. 1, a shut-off flap Z is fastened in a conventional manner to a flap shaft 3 running perpendicular to the pipe axis and is rotatably mounted with this in the pipe wall. However, in this case a memory metal coil 8 is held at a fixed point 37 on the inner wall of the pipe section 1 at some distance from the flap shaft 3. Its movable end engages directly on the shut-off flap 2 to the side of the flap shaft. On the side opposite the point of action of the memory metal coil 8, a return spring iO in the form of a spiral tension spring is tensioned between the locking flap 2 and another locking point 39 on the inner wall of the pipe section 1. If the temperature within the

Pipeline is below a certain limit, eg 85 ⁰ G, the return spring 10 holds the shut-off flap 2 with the Memorymetal1 coil 8 stretched parallel or approximately parallel to the pipe axis in the "open" position. ■ As soon as the temperature in the pipe exceeds the predetermined limit of eg 85 ⁰ C, for example due to fire, the Memorymetal1 coil 8 contracts and pulls the shut-off flap 2 into the "open" position.

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In a matter of seconds, against the action of the return spring across the pipe axis in the "closed" position. This prevents a fire from spreading through the exhaust pipe.

Another embodiment of a shut-off device that closes when the temperature in the pipeline increases is shown in Fig. 5 and 6. In this case, flap wings 42 made of spring sheet are fastened in a square pipe section 1 with their base edge 42a to one of the four flat inner surfaces of the pipe section 1 in such a way that in the "open" position they rest against the inner wall of the pipe section 1 and can be bent against their own spring force towards the pipe axis. They are cut in such a way that all flap wings 42 together in the "closed" position, in which they are bent towards the pipe axis, form a shut-off device in the form of a polygonal dome, the axis of which lies on the pipe axis or in the immediate vicinity of it. Each flap wing 42 forms a dome segment in the "closed" position and a return spring in the form of a leaf spring resting on the inner wall of the pipe section 1 in the "open" position.

Each flap wing 42 is connected in the area of its tip to the movable end of a memory metal coil 8 held at a fixed point in the pipe section 1. The fixed point 47 is located in the pipe axis on a web 43 crossing the pipe axis, which is fastened in the pipe wall in the base plane of the flap wings 42. The movable end of the memory metal coil 8 is connected in a force-tight manner to each flap wing 42 by a connecting wire 48 engaging in the area of the wing tip.

When the temperature in the pipeline rises above a certain value, the pressure at lower temperatures contracts.

Temperature stretched memory metal coil 8 in the direction of the pipe axis to its fixed point 47. The flap wings 42, each connected by the connecting wire 48 to the movable end of the memory metal coil 8, are bent with their tips towards the pipe axis so that they form a shut-off device in the form of a square dome. As soon as the memory metal coil 8 has cooled down again to below the certain value, it stretches towards the wing tips under the effect of the flap wings, which now act as return springs. The flap wings can again rest against the pipe wall due to their own spring effect and open the passage.

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Claims (4)

PATENT ENGINEER/; ·.· *·.:.. '."'.'."'. Dlpl.-Landw. P. Thielmann.·-. '■>·' *-.* ' "·..'*·..'&bgr;&agr;&tgr;&ogr;&rgr;&egr;&agr;&eegr; patent c/6ttotnen Ajn Eschenbaro 1* - Tel. CO6-4613 2733 D-356O BI &Egr; DEN KOPF / LAH N 03 12 Rathgeber Friedrich Rathgeber KG PROTECTION CLAIMS 1. Thermally controllable shut-off device in pipelines for gaseous flow media, in particular in air conditioning and heating systems, exhaust air and flue gas pipes, whereby a movable shut-off flap or several movable, interacting flap wings are arranged as an actuating element in a pipe section, &kgr; characterized by J that the actuating element of the shut-off valve (2) is fczw. Flap wings at least one at a fixed point (7) is provided which is assigned a controllable heat source or which is arranged in the media flow of the pipeline (1), the movable end of which is connected to the shut-off flap (2) or the flap wings in a force-locking manner and which, upon contraction f due to heating, closes the shut-off flap (2) or the Flap wing actuated against the action of at least one return spring (10). 2. Shut-off device according to claim 1, characterized by the following features. i i * Ht **tt t * 4 Ii IUi &bull; 4 4 · * t·# 1 < < t« *t*4l t * * t trt« "&igr; a) In a pipe section (1), a shut-off flap (2) is fastened in a manner known per se to a flap shaft (3) running perpendicular to the pipe axis and is rotatably mounted with the latter in the pipe wall; b) a double crank (4) is attached to an end of the flap shaft (3) protruding from the side or top of the pipe section (1), which has two opposing crank pins (5, ö), with the movable end of a memory metal coil (8) held at a fixed point (7) engaging one crank pin (5), while the free end of a return spring (10) also held at a fixed point (9) engaging the other crank pin (6); c) in the immediate vicinity of the memory metal1 coil (8) an externally controllable heat source is arranged in the area of its end held at the fixed point (7). 3. Shut-off device according to claims 1 and 2, characterized by the following features: a) The externally controllable heat source is an electrical resistance (11) arranged on a control panel (13) fixed to the pipe section (1) and surrounded by a removable housing (12); b) a transformer (14) is also arranged on the control panel (13), the primary side of which is connected via a power line (15) to a device that controls the power supply; c) the resistor (11) is connected to the secondary side of the transformer (13) with a fuse (16) in between and SO ilii Il ill« tt * Hi placed on the control panel (13)» that it is in
in the immediate vicinity of the Memorymetaii spiral (8)
in the area of its fixed point (7) also placed on the control panel (13)
final section" 4. Shut-off device according to claims 1 to 3, S thereby qek ^p nnzoichnet. '& that in the heat generated by the resistor (11) | contracted memory metal coil (8) the locking | flap (2) "open" and at kaiter^stretched | Memorymetai1 helix (8) is "closed". | 5. Shut-off device according to claim 1*, wherein in itself | known manner in the pipe section (1) a | Shut-off valve (2) at a position perpendicular to the pipe axis p extending flap shaft (3) and with | this is rotatably mounted in the pipe wall, J characterized by the following | g e &eegr; d e Features: I ä) The memory metal coil (8) is attached to a | Inner wall of the pipe section (1) in some | Distance from the flap shaft (3) arranged | Fixed point (37) with its movable j end laterally from the valve shaft (3) at the Locking flap (2) engages; J b) on the side opposite the memory metal coil (8) | The locking flap side is between the | Locking flap (2) and a fixed point (39) on _the inner wall of the pipe section (1)
Locking flap (2) with extended memory metal coil (8) in "closed" position
Return spring (3) tensioned. tt M Ht it at > · · · f · · » « < t 6< Shut-off device according to claim 1, wherein the shut-off device consists of at least two flap valves (22)*. characterized in that the flap wings consist of spring sheet, whereby they are each fixed immovably in a pipe section (1) with a base edge and their frgion surfaces simultaneously form the shut-off device and return springs acting against at least one memory metal coil (8). 1. Shut-off device according to claim 6, characterized by the following features: a) Two flap flaps (22) are fastened together with their base edge (22a) to a web (23) arranged in the middle of the pipe section (1) transversely to the pipe axis and parallel to the pipe axis in such a way that in the "open" position they lie one against the other in the middle of the pipe section (1) in the direction of the pipe axis; b) the flap wings (22) are each curved outwards starting from their base edge (22a) and cut in such a way that their outer edge (22b) lies tightly against the inner wall of the pipe section (1) in the "closed" position; c) each of the two flap wings (22) is frictionally connected in the area of its outer edge (22b) to a movable end of a memory metal coil (8) held at its other end within the pipe section (1). 8. Shut-off device according to claims 6 and 7, characterized by the following features: ff* 4 fl **· ff« 4 · &bull; 446 4*4 · · 4 4 *· * * 4 t 4 4t «4 4 4 44· 4 4 4 4 a 4 4 * 4 4 4*4 t * 4 4 &diams; « · &bull; Hl »· 4 4 4 A4 44 a) The flap wings (22) each have a recess (24 ₄ 25) in the central edge region in the form of a radially extending wide slot which extends close to the outer edge (22b) of the flap wing (22), wherein a retaining arm (26, 27) protruding from the plane of the flap wing (22) on its concave side is arranged on the outer edge of the recess (24, 25); b) the two ends of a memory metal coil (8) running within the recesses (24, 25) across the connecting web (23) of the flap wings (22) are attached to the holding arms (26, 27). 9. Shut-off device according to claims 6 and 7, characterized in that one end of at least one memory metal coil (8) is fixed to a web (23) crossing the pipe axis at some distance from the free edges (22b) of the flap wings (22), the other, movable end of which is connected to at least one of the flap wings (22). 10. Shut-off device according to claim 6, characterized by the following features: ä) At least three flap wings (42) made of spring sheet metal are each immovably attached by at least one straight section of their base edge (42a) to a part of a pipe section (1) that is flat at least in this area; b) each flap wing (42) is cut in such a way that all flap wings together in the "closed" position form a shut-off device in the form of a 14 f· φ «44 4 4 4 4 4 4 « < 441 · * « » &bull; 4 4 1 44· 44 44 * 4 444 4441444 41 4 4 44 44 4 4111 «tilt* 14 4 M Il form a polygonal dome whose axis is at or on the tube axis" c) each flap leaf (42) forms a dome segment in the "closed" position and a return spring in the form of a leaf spring in the "open" position, which rests against the inner wall of the pipe section (1) and is connected in the area of its tip to the movable end of a memory metal coil (8) held at a fixed point (47) in the pipe section (1). Shut-off device according to claim 10, characterized in that in the pipe section (1) in the axial direction on the side of the movable ends of the flap wings (42) a web (43) or similar fixed point device is arranged which crosses the pipe axis and to which a (»Semorymetal 1) spiral (8) is fastened in the region of the pipe axis, the movable end of which is connected in a force-fitting manner to each flap wing (42) by a wire (48) or similar connecting element engaging in the region of the wing tip.