Device for keeping a roof free of snow

Abstract

Device for keeping a roof (4) free of snow by blowing a gaseous medium along the roof (4) by means of a pipe system (5) laid along a roof surface (4) with openings (17), wherein the pipe system (5) has several straight pipe sections (8) which a) are spaced from the roof surface (4) by means of fixing (i) by means of fastening clamps (18) with a base (20) on the underside, or (ii) by means of elongated elements which overlap the roof surface (4) from one side to the opposite side, or (iii) by means of tension wires or cables, coupled with spacers loosely standing on the roof, and which b) have lateral discharge openings (17) on the outer surface, which are arranged in areas of the pipe or pipe sheath where the normal to the sheath surface is approximately parallel to the roof surface (4).- plane, which, however, are slightly displaced towards the roof surface (4), and which furthermore c) run parallel to each other, in particular transverse to a roof slope, i.e. at a constant level, and d) which are fed via a throttle and / or control valve from a pressure vessel, which in turn is charged by a compressor up to a certain pressure level, characterized in that e) the lateral discharge openings (17) have an elliptical or slot-shaped cross-section, so that the fanning out of the jet direction in a lateral, i.e.the horizontal direction is greater than the vertical fanning of the jet direction, wherein the longer main axis of a discharge opening (17) runs in the longitudinal direction of the relevant pipe section (8), i.e. approximately parallel to the roof surface (4), while the shorter main axis, on the other hand, runs transversely to the relevant pipe section (8), i.e. approximately vertically, and wherein f) the even pipe sections (8) are fed in alternating sequence from their right end (11) or from their left end (12), wherein the first, third, fifth, etc. pipe section (8) is coupled to a connecting pipe (15), the intervening even-numbered pipe sections (8), i.e. the second, fourth, sixth, etc., are coupled to another connecting pipe (16), while the opposite pipe ends are closed, so that the shape of two interlocking combs results.

Description

The invention relates to a device for keeping a roof free of snow by blowing a gaseous medium along the roof by means of a pipe system laid along a roof surface with openings, wherein the pipe system has several straight pipe sections which a) are spaced from the roof surface by means of fixation (i) by means of mounting clamps with a base on the underside, or (ii) by means of elongated elements which overlap the roof surface in question from one side to the opposite side, or (iii) by means of tension wires or cables, coupled with spacers loosely resting on the roof, and which b) have lateral discharge openings on the outer surface which are arranged in areas of the pipe or pipe shell where the normal to the outer surface is approximately parallel to the roof surface.-plane, which, however, are slightly shifted towards the roof surface, and which furthermore c) run parallel to each other, in particular perpendicular to a roof slope, i.e. at a constant level, and d) which are fed via a throttle and / or control valve from a pressure vessel, which in turn is charged by a compressor up to a certain pressure level. Long, cold winters can pose a serious problem, especially for flat roofs, as snow accumulates on them. If there isn't an occasional warmer period with thawing to melt the snow, the snow load becomes increasingly heavy throughout the winter and can eventually cause the roof to collapse. This not only endangers the goods and equipment inside the building, but also puts human lives at risk. To avoid this, the building owner would have to access the roof at regular intervals and clear it of snow and ice. However, this is also not entirely without risk, because flat roofs are usually not secured by railings or similar devices, and a person can easily lose their balance on the slippery surface. Furthermore, even simply walking on a roof and the associated additional weight can lead to a local overload. JP S57-33658 A discloses a device for keeping a roof free of snow. Parallel pipes are laid on the roof, with lateral outlets for heated air arranged in the pipe casing. This air is intended to thaw and melt any existing snow accumulation on the roof, or even prevent it from forming altogether. While the outlets are slightly inclined towards the roof surface, they have approximately circular cross-sections, so that a significant portion of the outgoing air is always blown in other directions instead of onto the roof. Furthermore, all pipes are connected to a compressed air source at the front of the house, meaning that the roof on the side facing away from the compressed air source is defrosted less effectively. A similar arrangement can be found in JP S62 - 112 859 A. This also addresses the task of keeping a roof free of snow and proposes a device with several pipes laid on the roof. Their inlets are connected via a manifold along the gable wall of the house to a blower installed near the ridge. Consequently, the roof is de-iced unevenly. Furthermore, the outlet openings are nozzle-shaped, producing a very narrow jet of air. JP S63-134764A also shows a device for clearing snow from a roof using hot air. On a house with a gable roof, two main pipes are laid parallel to the ridge, next to it, and connected to a blower inside the house at one gable end. Shortly after, branch pipes extend from these two main pipes on the side facing away from the ridge. These branch pipes run down the corresponding half of the roof to the eaves, where they are capped. Hot air escapes through longitudinal slots on the sides of these branch pipes and melts any snow that may be present. The JP H10 - 266 628 A addresses the problem of de-icing a domed roof, where a pipe system is installed above the roof to allow air near the roof to de-ice. Due to the domed shape of the roof, however, there are no straight pipe sections; all pipe sections are curved, e.g., circular. Furthermore, the air is introduced on one side of the domed roof, so the melting effect on the opposite side of the roof is rather minimal. The disadvantages of the aforementioned prior art result in the problem initiating the invention: to find a way to keep a roof free of snow as evenly as possible without requiring a person to enter the roof and thereby put themselves in danger. The solution to this problem in a device of this type is achieved by: e) the lateral discharge openings having an elliptical or slot-shaped cross-section, so that the lateral, i.e., horizontal, dispersion of the jet direction is greater than the vertical dispersion of the jet direction, in that the longer principal axis of a discharge opening runs in the longitudinal direction of the relevant pipe section, i.e., approximately parallel to the roof surface, while the shorter principal axis, on the other hand, runs transversely to the relevant pipe section, i.e., approximately vertically, and wherein f) the even pipe sections are fed in alternating sequence from their right end and from their left end, in that the first, third, fifth, etc. pipe section is coupled with a connecting pipe, and the intervening even-numbered pipe sections, i.e., the second, fourth, sixth, etc., are connected by a connecting pipe., however, with a different connecting pipe, while the opposite pipe ends are closed, resulting in the shape of two interlocking combs. Ideally, this gas creates such a strong air current that the snowflakes falling from the sky are unable to settle or adhere to the roof. Instead, the snowflakes are kept in motion or swirled around and blown off the roof. If the cross-section of an opening is comparatively small in relation to the inner cross-section of the pipe in question, e.g. less than 20%, preferably less than 10%, in particular less than 5%, then the flow resistance in the pipe is low, and the pressure generated, e.g., by a compressor, propagates almost unchanged to the openings, so that a maximum discharge pressure prevails there. Provided the pressure in the piping system is not too high, e.g., only a few atmospheres of overpressure, a preferably gas-tight hose can be used as the piping. Alternatively, and / or in addition, the piping system can also have one or more pipe sections. These are more robust and therefore suitable for higher pressures. The pipe or conduit system has one or more straight sections. These straight pipe or conduit sections can be arranged approximately parallel to each other, so that a roof surface, often rectangular, can be supplied with a continuous gas flow by several pipe runs arranged at regular intervals. Preferably, these straight, parallel pipe sections run perpendicular to any existing roof slope, i.e., at a roughly constant level. This allows the gas flows or the flow pattern to be oriented downslope, so that the effect of the gas or air flow is amplified by the force of gravity acting on the sloping roof, ultimately blowing the snowflakes towards the roof edge. The distance between two adjacent, straight, parallel pipe or conduit sections depends on the energy of the gas flow exiting the openings, and thus on the gas pressure in the piping system and the cross-section of the openings. This is because each pipe is responsible for generating an airflow capable of carrying snowflakes to the next pipe. For this purpose, the distance should be less than 2 m, preferably less than 1.5 m, and particularly less than 1 m. By connecting two adjacent, straight, parallel pipe or conduit sections with at least one other pipe or conduit section, all pipe sections can communicate with each other, so that only a single supply line to a compressor is required. It is possible to connect several pipe sections in parallel in terms of flow characteristics, so that approximately the same pressure prevails within all the pipe sections in question. This can be achieved, for example, by connecting the adjacent ends of all parallel, straight pipe sections. The opposite pipe ends can then be sealed, similar to the structure of a comb. Alternatively, it would also be possible to interlock two such comb-like systems, so that only the ends of the next-but-one pipe sections, i.e.,The pipe sections are connected to each other every other pipe section, and the pipe sections in between are connected to each other at their opposite ends. This means that the continuously decreasing flow rate along the pipes in such a comb-like pipe system is roughly compensated for or supplemented by the decreasing flow rate in the opposite direction of the other comb-like pipe system. Finally, it is also conceivable to arrange the pipe system as a single, unbranched conduit with a meandering course. However, this is only recommended for smaller roofs, because otherwise entire roof areas might be supplied with only a comparatively low gas or flow pressure. A connecting section between two adjacent, straight, parallel pipe or conduit sections preferably follows a course that is oriented perpendicular or oblique to these sections. Particularly in the case of a meandering course, it is also possible for the connecting sections between each pair of adjacent, straight, parallel pipe or conduit sections to follow a curved course. The exhaust openings are preferably positioned along straight sections of pipe or conduit. The most important thing is to create an airflow that covers all areas of the roof surface. Openings on lateral connecting pipes are usually unnecessary for this purpose. To ensure a relatively homogeneous flow pattern, the discharge openings should be arranged approximately equidistantly along a section of pipe or conduit. The invention recommends that the discharge openings be arranged at intervals of less than 1.2 m, preferably at intervals of less than 1.0 m, and particularly at intervals of less than 0.8 m. For safety reasons, even intervals of less than 0.6 m or less than 0.5 m, or even less than 0.4 m, e.g., only 0.3 m or less, may be provided. The discharge openings should be located in areas of the pipe or conduit casing where the normal to the casing surface runs approximately parallel to the roof surface or plane, for example, inclined at angles of less than ±30° to the roof surface or plane, preferably at angles of less than ±25° to the roof surface or plane, and particularly at angles of less than ±20° to the roof surface or plane. This ensures that the jet direction optimally follows the roof surface and is thus maintained over relatively long distances. By arranging all the discharge openings of a pipe or conduit section on the same side of the pipe / conduit, a uniform, highly homogeneous flow pattern can be created. A further development of the invention serves the same purpose by arranging the discharge openings of adjacent pipe or conduit sections on the same side of the pipe / conduit, so that the openings of one section face the other, while those of the other face away from the first. In this way, the snowflakes are, so to speak, passed from one pipe to the next until they reach an edge of the roof surface and can then float to the ground. The openings have an elliptical or slit-shaped cross-section. The invention prefers a fanning of the beam direction in a lateral or approximately horizontal direction, i.e., approximately in the plane of the relevant pipe section, to an exit angle of, for example, 60°, while the vertical fanning of the beam direction can be comparatively small, for example, at an exit angle of only about 30°. For stability reasons, the pipes or conduits are fixed at regular intervals. This can be done, for example, using fasteners, particularly eyelets or clamps, which are fixed to the roof surface. For this purpose, the eyelets can each have a base with a flat contact surface, which is provided with mounting holes for fastening screws that are inserted and then screwed into a roof truss or a concrete roof. On the other hand, it can also be desirable to avoid damaging a roof surface, for example, if the roof is covered with roofing felt and thus sealed watertight. In such cases, pipes or cables can be fixed to elongated elements that run along the roof surface. These could be, for example, metal profiles that span the roof surface from one side to the opposite side, or tension wires or cables, for example, made of metal, especially steel, that are stretched approximately parallel to the roof surface, possibly combined with spacers that rest loosely on the roof to dampen vibrations of the tensioned cables. The pipe system is connected to a device that supplies the gaseous medium under increased pressure. This allows the pressure to be kept constant as needed, so that even during prolonged snowfall, the system according to the invention does not reach its limits. A compressor coupled to the inlet side of the pipe system is best suited for this purpose. On the other hand, the device for feeding in the gaseous medium has a pressure vessel, so that on the one hand the compressor does not have to run permanently and therefore electricity can be saved, and on the other hand the blowing effect of the system according to the invention does not diminish in the event of a temporary power failure. Finally, it is consistent with the teaching of the invention that the gaseous medium is air. This medium is available in unlimited quantities. It is not consumed in the process according to the invention, but rather released back into the environment. Further features, properties, advantages, and effects based on the invention will become apparent from the following description of a preferred embodiment of the invention and from the accompanying drawings. These show: Fig. 1 a schematic, perspective view of a building with a flat roof and a system according to the invention installed thereon for keeping this roof free of snow; Fig. 2 detail II from Fig. 1 in a larger view; and Fig. 3 a section through Fig. 2 along line III-III. Fig. 1 shows a building 1 in the form of a flat building, e.g. a shopping center, with four exterior walls 2, an entrance 3 and a flat roof 4. A pipe system 5 according to the invention is installed on the roof 4. This system is connected via an inlet pipe 6, which leads into the interior of the building, to a supply unit 7 located there, for example in an adjacent room. This supply unit 7 comprises a pressure vessel and a compressor. The compressor compresses room air, exhaust air and / or ambient air and thereby charges the pressure vessel up to a certain pressure level. From there, the compressed air is gradually released into the pipe system 5 via a throttle and / or control valve. The pipe system 5 comprises several straight, parallel pipe sections 8, of which only three are shown in Fig. 1. In reality, however, larger roofs usually have many more such parallel pipe sections, e.g. ten or more. If the roof 4 has a slope, the invention recommends that the straight pipe sections 8 run transversely to the roof slope, i.e., at a constant level, parallel to two roof edges 9, 10 of a rectangular roof surface. Preferably, these are the two longer roof edges 9, 10 and / or the two horizontally running edges, namely an upper roof edge 9 and a lower roof edge 10. The pipe sections 8 are fed alternately from their right end 11 and left end 12, respectively. For this purpose, a connecting pipe 15, 16 runs along each of the two remaining roof edges 13, 14. Each connecting pipe 15, 16 communicates on one side with the inlet pipe 6 and on the other side with a series of straight pipe sections 8. The arrangement can be such that the odd-numbered pipe sections 8 (i.e., the first, third, fifth, etc., viewed from a roof edge 9) are coupled to one connecting pipe 15, e.g., the one on the right in Fig. 1, while the even-numbered pipe sections 8 in between (i.e., the second, fourth, sixth, etc.) are coupled to the other connecting pipe 16, e.g., the one on the left in Fig. 1. The opposite ends of each pipe section 8 are preferably closed. The compressed air supplied to the straight pipe sections 8 via the inlet pipe 6 and the connecting pipes 15, 16 exits from there through openings 17 on the casing side. The openings 17 preferably all have the same cross-section, e.g. an elliptical shape, wherein the longer main axis of the ellipse runs in the longitudinal direction of a pipe section 8, i.e. approximately parallel to the roof surface 4, while the shorter main axis runs transversely to the pipe section 8 in question or approximately vertically. Preferably, all openings 17 are located approximately laterally on the pipe sections 8, in particular only on a single side, preferably on the side facing the lower roof edge 10. As can be seen in Fig. 3, the openings 17 are slightly offset from the horizontal towards the roof surface 4, so that the exiting air jet is inclined at a shallow angle to the roof surface 4, e.g., at a tangential angle of less than 30°. The airflow thus conforms to the roof surface 4, a fact further enhanced by the fact that the pipes 8, and therefore also the openings 17, are only a short distance from the roof surface 4, e.g., only 15 cm or less, in particular about 10 cm or less. The air outlet openings 17 are arranged equidistantly along the pipe sections 8. Since the distance between adjacent openings 17 is very small, e.g., only 30 cm or less, the sum of all airflows creates a flow pattern that is relatively homogeneous and directed from the higher roof edge 9 to the lower 10. This airflow transports descending snowflakes over the roof 4 to the illuminated roof edge 10. Snowflakes that have already fallen are stirred up again and then also carried away. The pipes 8 are preferably lightweight plastic pipes. Since the air exiting from one side exerts a lateral force on the pipes 8 due to the recoil principle, they must be secured. This is achieved using mounting clamps 18, each with an eyelet 19 that encompasses a pipe section 8 and has a base 20 on the underside. This base may have mounting holes through which fastening screws can be inserted to fix the pipe system 5 to the roof surface 4. These mounting clamps can be spaced further apart than the openings 17, for example, at intervals of 50 cm or 60 cm. If, for example, after a prolonged power outage, a more or less heavy layer of snow and / or ice has already formed on the roof 4, the compressed air can also be preheated before blowing out the snow and / or ice so that the layer of snow and / or ice is thawed. To determine when this measure is necessary, a video camera 21 or the like can be arranged on the roof 4, which is coupled to a monitor inside the building 1 for image display, so that the roof 4 can be observed and / or monitored from the inside.

Claims

Device for keeping a roof (4) free of snow by blowing a gaseous medium along the roof (4) by means of a pipe system (5) laid along a roof surface (4) with openings (17), wherein the pipe system (5) has several straight pipe sections (8) which a) are spaced from the roof surface (4) by means of fixing (i) by means of fastening clamps (18) with a base (20) on the underside, or (ii) by means of elongated elements which overlap the roof surface (4) from one side to the opposite side, or (iii) by means of tension wires or cables, coupled with spacers loosely standing on the roof, and which b) have lateral discharge openings (17) on the outer surface, which are arranged in areas of the pipe or pipe sheath where the normal to the sheath surface is approximately parallel to the roof surface (4).- plane, which, however, are slightly displaced towards the roof surface (4), and which furthermore c) run parallel to each other, in particular perpendicular to a roof slope, i.e. at a constant level, and d) which are fed via a throttle and / or control valve from a pressure vessel, which in turn is charged by a compressor up to a certain pressure level, characterized in that e) the lateral discharge openings (17) have an elliptical or slotted cross-section, so that the fanning out of the jet direction in a lateral, i.e.the horizontal direction is greater than the vertical fanning of the jet direction, wherein the longer main axis of a discharge opening (17) runs in the longitudinal direction of the relevant pipe section (8), i.e. approximately parallel to the roof surface (4), while the shorter main axis, on the other hand, runs transversely to the relevant pipe section (8), i.e. approximately vertically, and wherein f) the even pipe sections (8) are fed in alternating sequence from their right end (11) or from their left end (12), wherein the first, third, fifth, etc. pipe section (8) is coupled to a connecting pipe (15), the intervening even-numbered pipe sections (8), i.e. the second, fourth, sixth, etc., are coupled to another connecting pipe (16), while the opposite pipe ends are closed, so that the shape of two interlocking combs results. Device according to claim 1, characterized in that the distance between two adjacent, straight, mutually parallel pipe or conduit sections (8) is less than 2 m, preferably less than 1.5 m, in particular less than 1 m. Device according to one of the preceding claims, characterized in that the discharge openings (17) are arranged approximately equidistantly along a pipe or conduit section (8). Device according to one of the preceding claims, characterized in that the discharge openings (17) are arranged at intervals of less than 1.2 m each, preferably at intervals of less than 1.0 m each, in particular at intervals of less than 0.8 m each. Device according to one of the preceding claims, characterized in that the discharge openings (17) are arranged in areas of the pipe or conduit sheath (8) which are inclined at angles of less than ±30° to the roof surface (4) or plane, preferably inclined at angles of less than +25° to the roof surface (4) or plane, in particular inclined at angles of less than ±20° to the roof surface (4) or plane. Device according to one of the preceding claims, characterized in that the discharge openings (17) of a pipe or conduit section (8) are arranged on the same side of the pipe / conduit (8). Device according to one of the preceding claims, characterized in that the discharge openings (17) of adjacent pipe or conduit sections (8) are each arranged on the same side of the pipe / conduit (8), so that the openings (17) of one section (8) face the other, but those of the other face away from the former. Device according to one of the preceding claims, characterized in that the pipes or lines (8) are fixed at regular intervals. Device according to one of the preceding claims, characterized in that the gaseous medium is air.

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