WO2010009963A1 - Safety screen - Google Patents

Abstract

The invention relates to a safety screen (100), which comprises a fence mesh or screen structure fastened between stationary fastening points (10, 15) and at least one sensor element (11, 12, 13, 14), wherein at least one tubular element (20, 30) is present, through which a fluid can flow and which extends between the stationary fastening points (10, 15) as part of the fence mesh or the screen structure. At least one pressure sensor element (11, 13) and/or one flow sensor element (12, 14), which is to be connected to an alarm transmitter device, are arranged on the tubular element (20, 30) and/or on a further fluid line connected to the tubular element (20, 30). The safety screen can be used as a collector for a heat pump system if a heat transfer fluid flows through the tubular element.

Description

 security bars

The invention relates to a security grid, comprising a Zaungeflecht spanned between fixed attachment points or a stationary grid structure and at least one sensor element.

For the purposes of the invention, a safety grid is understood to mean parts of enclosures such as fences and gates, but also protective elements in front of wall openings and even inside walls of safety surface elements.

Safety fences or safety grids are used to detect attempts to pass through and to supply a signal to an alarm device. For example, wire mesh fences are known in which sensor cables pass through one or more wires. If these sensor cables are severed when the fence mesh is cut, then an alarm signal can be generated via a closed-circuit current monitor. These safety fences have proven themselves but can be manipulated in such a way that both sides of an intended access wall the signal wires are exposed and connected via a cable loop.

The object of the invention is therefore to provide a security grille, which is better protected against manipulation.

The term "safety grille" summarizes in the context of the present invention foreclosure and fencing elements of all kinds such as fences and gates, whether they are made of solid structures or made of flexible.

This object is achieved in that at least one tube member is provided, which is flowed through by a fluid and which extends as part of Zaungeflechts or the grid structure between the stationary attachment points, wherein at the tube member or a connected to the tubular member fluid line at least one pressure - And / or a flow-sensor element is arranged, which is connected to an alarm device.

Whenever a tube element integrated into the fence mesh or the grid structure is severed, leakage inevitably occurs, which manifests itself as a pressure drop as well as a change in flow behavior. Both a pressure sensor element in the conduit and a flow sensor element are each capable of fulfilling the alarm function.

Preferred is a combination of both sensors. As a result, the sensitivity of the alarm device can be set lower, so that false alarms can be reduced. Since there are preferably a plurality of tube elements connected to a meandering tube, multiple clamping of the tube element could result in the pressure being maintained, the pressure sensor thus signaling no drop, and a piece located between the stop points could be removed. In this case, however, the missing flow would be registered by the flow sensor element and an alarm would be triggered.

If a piece were separated out of the tube element and rapidly replaced by a bypass tube, then only a weak short-term drop in flow with high sensitivity of the alarm device would be registered. A pressure change would occur nevertheless and could be recorded accordingly.

For the distribution and alignment of the tube elements different variants are conceivable. In a simplest embodiment, the tubes extend in the longitudinal direction of the fence between the attachment points. A feed line is arranged in a first fence post, a return line in an adjacent fence post. To close the circuit then a line would have to be laid in particular underground.

If several parallel tube elements are connected in meandering form, the result of the loop formation is the possibility of integrating flow and return in a fence post. From there, two fence panels can then be controlled on both sides of the fence post, so that the number of fence posts, which is to be provided with supply and return lines, is reduced. If the parallel sections of the meandering tube extend horizontally, there is the advantage that a venting point can be arranged in the uppermost strand.

The tubes can also be combined in a vertical form to a fence mesh. But then a bleed valve must be placed on each bend at the top.

According to a further alternative, the tube elements are arranged as in a wire netting. The wire mesh has the advantage that it can be easily manufactured and is very space-saving transportable. The Zaungeflecht can be prefabricated for the entire intended fence height and then needs to be pulled apart only at the installation.

It is also possible to form a Zaungeflecht from corkscrew-shaped spirals at the installation and then produce fluid connections in the field of fence posts.

For thin tube elements with a small opening cross section, a flow with a liquid is preferred, in particular a brine or a mixture of antifreeze and water, so that a flow through the tube elements is ensured even at low temperatures.

Thicker tube elements, as can be used for example in welded Zaungittern, can also be acted upon with compressed air. The safety grid formed according to the invention can be used in a simple way to monitor itself. If leakage occurs due to damaged corrosion, etc., this will generally occur creeping, that is to say, the pressure gradient with a low gradient can be detected as a technical fault via a downstream alarm device, whereas an abrupt drop in pressure with a large gradient will result in serious damage , in particular a violent severing of at least one tubular element, indicates.

The individual pipe elements should preferably extend over the entire fence field. The distances between parallel guided tube elements should be less than 25cm in order to avoid bending apart to an opening width that could allow a person to step through.

It is also advantageous to feed the sensor cable into individual tube elements. The flow is not affected by this. In the case of severing, another sensor signal is obtained by the quiescent current-monitored sensor cable. In addition, the retracted cable can also serve to connect remote pressure or flow sensors with a central alarm device, so that no exposed lines must be used for it.

Surprisingly, the improvement of the monitoring of the fence element results in an unusual possibility of use, as it is filled with the fluid-filled tubular elements, even at the fencing have a considerable length only a medium-sized plot of a family house, a heat exchanger is available, which is suitable for operating a heat pump. From the air or - in the case of a safety grille, which extends into the ground and / or in a foundation - heat absorbed into the soil can be transferred to the guided in the tube element fluid and then brought by means of a heat pump to a higher temperature level.

At a height of the safety grid of 2 meters, which is usually required for the safety against overcrossing, at least 11 parallel tube elements would thus be required at the maximum distances specified below. In the case of a medium-sized plot of a single-family dwelling of, for example, 20 m by 25 m edge length, this results in a circumference of 90 m and thus almost 1000 m length of pipes through which liquid flows, if all the fence gauges are filled with fluid. This great length favors the possible use in a heat pump system.

It is particularly advantageous to lay the flow-through tube elements into the soil, as this will create a shelter for the actual purpose of the safety grid to protect a property against unauthorized access.

On the other hand, the embedding of subsections into the soil with the additional possible use in the context of a heat pump has the advantage that for winter operation of the heat pump is a sufficient collector surface in the ground is given, where the temperature is relatively constant in winter and even at frost above the air temperature can lie. With additional use of the safety grille in the context of a heat pump system, it is advantageous to be able to control the guided in the ground as the free-standing sections of the tube elements via separate supply and return lines.

If the areas above and below the ground level are switched together on a case-by-case basis, any energy surplus that can occur, especially in summer, can be compensated by cooling down a fluid in the ground that is too hot in the tube elements.

In order to create greater heat storage capacities and at the same time to increase the security against undermining, one embodiment provides that the flow-through tubular elements extend into a foundation running continuously between the attachment points. Only the greater mass and heat capacity of the massive building material, e.g. of concrete, makes it possible to create large heat buffers that are equally useful for preheating and cooling.

Advantageous are latent heat accumulators which contain "phase change materials" (PCM), whereby the heat of fusion or solution of a substance is utilized during the phase transition, the heat introduced leads to the melting of the PCM, in a later initiated crystallization heat of crystallization is released the fluid flow can be reheated.

Security-critical buildings such as prisons have security grilles at the window openings. Partly walls are also internally reinforced to an outbreak to prevent. Successful outbreaks of prisoners, however, are usually due to the fact that the breakthroughs are prepared by low material removal over a long period of time, which remains undetected. For this purpose, as another object of the invention to detect breakthrough attempts in an early stage.

This object is also achieved by a security grille according to the invention, because even a small leak in the tube element leads to the delivery of a signal, even if the damage is not yet so far reaching that a breakthrough is possible. The tube loops can enclose massive steel bars, so that an attack on the massive structures is impossible without having previously triggered an alarm signal.

If the fluid dyed with dyes, as you are known, for example, from Geldkoffern, and the fluid is promoted under increased pressure in the tube loop, so it inevitably comes with manipulations that the fluid squirts out and marks the offender, or at least its immediate environment ,

In a security grid according to the invention, which is integrated, for example, in the wall of a prison cell, the inner tube loop must also be severed in order to achieve a breakthrough. It is therefore not possible to undermine a wall disc undetected from the inside and then break out with a sudden break through the remaining structure. The fluid-filled tubes can be used as an additional effect in terms of climate technology and used for space heating or cooling.

The invention will be explained in more detail with reference to the drawing. The figures show in detail:

Fig. 1, 2a-2c security grille in various embodiments, each in a schematic side view;

FIGS. 3a-3d are diagrams with measured values of sensor elements plotted against time;

Fig. 4 is a trained as a chain link fence security grid in a schematic side view; and

5 shows two linked fields of a further embodiment of a security grid in a schematic side view.

FIG. 1 shows a security grille 100 designed as a security bridle, which comprises two fence posts 10, 15, which are anchored in foundations 41 in the ground 42. The fence posts 10, 15 are hollow inside and take forward and return lines 21, 22, 31, 32 and pressure sensors 11, 13 and flow sensors 12, 14 on.

Between the fence posts 10 extend in a horizontal orientation a plurality of tube elements. Neighboring tube elements are connected in pairs in such a way that over the entire height of the part of the fence field lying above the earth level 43 only a single, meander-shaped tube loop 20 results. The same applies to the area of a fence field, which is buried in the ground, to create a Untergrabschutz the safety gate 100. Here a meandering tube loop 30 is formed.

A vent valve 16 is disposed at the top of the fence post at a highest point of the tubular member.

To reinforce the tube loops 20, 30 are each crossed by vertical Füllstäben 23, 33 and connected thereto, z. B. welded.

Due to the meandering in the right fence post 15 only the fasteners take place and the vertical connecting parts are added. All connections are collected on the left fence post 10 led to a junction box, where the supply and return lines 21, 22, 31, 32 can be coupled to other modules, such as a circulating pump.

The sensor elements 11, 12, 13, 14 are connected within the fence post 10 with the lines and can be coupled via electrical connections, not shown, with an evaluation or alarm unit.

Figures 2a to 2c show safety fences 210, 220 and 220 ', which are constructed very similar to the embodiment of Figure 1. Only the arrangement of the tube elements and / or the foundation formation are different. Therefore, no sensor elements and the like are shown in these figures. The sensor arrangement in the forward and / or reverse and the operation of the safety grid is as in the embodiment described with reference to FIG. In Fig. 2a, a safety grid 210 is shown, in which between two fence posts 215 parallel, horizontal Füllstäbe 219 extend. A meandering tube loop 211 is formed by a plurality of horizontal tubes connected end-to-end via short connectors so as to provide a fluid conduit extending from a flow connection point 213 on the left fence post 215 to a reflux connection point 214 on the right fence post. At the fence posts 215, a direct connection to adjacent security fences can be made so that a chained tube loop results. The fence posts 215 are fixed in point foundations 214 in the soil 1. The fence panel, in particular the tube loop 211, extends to the ground level 2.

In FIG. 2b, in a safety grid 210 ', a tube loop 211' is again formed from a multiplicity of parallel tubes which are alternately connected to one another in pairs. In this embodiment, the tube loop 211 'extends below ground level 2 into a solid concrete foundation 214' that extends below the guard rail 210 'as a tambour protection.

2c, a latent heat accumulator 216 "is incorporated within the foundation 214" as modified from the embodiment of Fig. 2b. The tube loop 211 "extends with the lower portions of its tubular elements through the top of the foundation 214" in the latent heat storage 216 ". FIG. 4 shows, in a highly schematic view, a safety grid 300, which is designed as a mesh wire fence mesh 320. In the left fence post 310, a flow line 311 and a return line 312 are formed, from each of which emanate a plurality of hollow, tubular mesh wires. In the fence post adjacent mesh wires are connected, so that there is a reversal of the horizontal flow direction. The fluid flow finally ends in a return line 12 '.

5 shows a safety grid 300, in which a plurality of parallel tube elements 311 are arranged between an upper and lower manifold 312, 313, whose mouths are respectively connected to the manifolds. If one of the tube elements 311 connected in parallel is severed, fluid can continue to flow through the adjacent tube elements. Nevertheless, a pressure drop can be registered as an alarm signal.

The combination of pressure and flow sensors or multiple pressure sensor elements or multiple flow sensor elements can provide increased safety for the detection of breakthrough attempts while at the same time reducing the false alarm rate.

Different scenarios will be explained with reference to the curves of pressure and volume flow over time shown schematically in FIGS. 3a to 3d. The values po and V ₀ correspond to the operating setpoint values of pressure and volume flow. The lines above and below each indicate the tolerance band of permissible deviations which are not yet considered alarm criteria. 3a shows a diagram in which the continuous line shows the pressure over time and the dashed line shows the volume flow over time. The flow sensor 12 for detecting the volume flow is arranged in the return line 22 of the tube loop 20, the pressure sensor 11 in the flow 21. If the tube loop 20 at the time ti completely cut, there is a sudden pressure drop, and also the flow rate expires rapidly, as in Fig. 3a shown.

FIG. 3b shows the measured value course in a breakthrough experiment in which a rod has been disconnected from the tube loop 20 at the time ti. Due to the usually existing pressure control in the delivery circuit, where, for example, the pump is controlled pressure-dependent, it comes even in normal operation to pressure fluctuations, which are characterized by the small pressure drops left and right in the diagram of FIG. 3b.

Fig. 3c shows the drop of the pressure as well as the volume flow with a very low gradient. This measured value course is characteristic for a gradual loss of fluid as a result of technical leaks, corrosion, etc. A determination of the gradient can be used to distinguish breakthrough tests and technical faults.

When clamping at two remote locations according to the scenario of Fig. 3d is achieved that the pumping circuit is interrupted, but the fluid does not flow out. This makes itself felt in possibly still running feed pump in a slight pressure increase at the time ti, then the pressure levels off due to the pump control but then at normal operating level po again, so that by the evaluation of the pressure sensor 11 of the breakthrough attempt could only be detected if the tolerance interval for pressure fluctuations would be made narrow, but an increased false alarm frequency would have to be accepted.

Therefore, the additional evaluation of the flow sensor 12 is advantageous, because even in the case of a double blockade of the tube loop 20, the flow dries up and drops below an alarm threshold F _1st

FIG. 3d is based on the following scenario:

Experienced offenders could put a bypass cable through the cut-out tubes to bypass the cut-out section. Even with clever action but at the moment of severing the tube elements at least a slight pressure drop can be registered, even if the bypass line is clamped very quickly. The same applies to the flow rate. The alarm signal is generated here by an AND operation if both measured values simultaneously fall below a first threshold pi or F ₁ . The two threshold values pi and F ₁ are still within the range of permitted fluctuations. However, the occurrence of such fluctuations is then defined as an alarm criterion in particularly tamper-evident security fences, when the two peaks are at a certain time interval from each other. Calculated or empirically can be concluded from the position of the pressure sensor and the flow sensor to each other on the approximate location of the point of interruption, so that conclusions are to be drawn, whether in the fence field itself lies or in the range of the feed pump. A technically induced failure of the feed pump, for example, would only lead to a pressure drop in the flow and then also with a time delay to a drop in the volume flow in the return and forms in accordance with "intelligent" programming no alarm criterion.

The location information of the damaged area can be forwarded to camera control systems known per se, which can then direct the image to the damaged area. Thus, an alarm center receives not only the information that a breakthrough attempt is made, but also where this takes place, so that by means of which targeted measures can be taken.

3e shows the measured values of two pressure sensors, of which the measured value of the upper line has been recorded by a pressure sensor 11 in the supply line 21 and the lower value by a pressure sensor in the return line. Shown is a situation similar to Fig. 3b, where a multiple clamping of the tube member ensures that no liquid leaks. When disconnecting a slight increase in pressure is observed in the flow, because the feed pump works against the obstacle until it shuts off automatically and the pressure switch blocks the flow line. In return, however, the pressure gradually decreases, because no fluid flows through the clamped flow. The gradient of the pressure drop in the return depends on how the further cycle is designed, whether, for example, check valves are present or whether a centrifugal or diaphragm pump is used. Here, too, an alarm criterion can be defined by linking the two measured values, if at both pressure transducers simultaneously the illustrated characteristic changes take place.

If, in addition to the double pressure transducers, the previously described flow sensor is present and evaluated, further alarm criteria can be defined and possible false alarms can be prevented.

It is advantageous to record characteristic pressure-time or volume-flow time profiles in the established safety grid and to define therefrom the threshold values as well as time intervals, which can be incorporated into a database. An evaluation unit can then use the comparison data to check the measured values continuously detected during monitoring operation for the presence of alarm or fault criteria.

Claims

Claims: A security grid (100; 100 '; 210; 210'; 210 "; 300) comprising an intermediate fixed attachment point (10, 15, 10 ', 15', 215) attached fence mesh or a grid structure and at least one sensor element (11, 12, 13, 14), characterized by at least one tubular element (20, 30; 20 '; 211; 211'; 211 "; 311) through which a fluid can flow and which forms part of the fence mesh or the grid structure between the fixed attachment points (10, 15; 215 ', 211 "), and / or one connected to the tubular element (20, 30; 20'; 211; 211 '); 211"; 211 "; 211 ", 311), at least one pressure sensor element (11, 13) and / or a flow-through sensor element (12, 14) is arranged, which is to be connected to an alarm device. 2. Security grille (100) according to claim 1, characterized in that parallel guided tube elements at the boundary edges of the fence mesh or the grid structure to a meandering tube (20, 30) are connected. 3. Security grille (100, 100 ') according to claim 1 or 2, characterized in that the attachment points are designed as fence posts (10, 15; 10', 15 '), wherein on one of the fence posts (10, 15; 15 ') are each a connection for at least one flow line (21, 31, 21') and for a return line (22, 32, 22 ') are arranged. 4. Safety grid (100, 210 ', 210' ') according to one of claims 1 to 3, characterized in that the flow-through tube elements (211', 211 ") extend into the soil or a tube element (30) in the ground ( 1) is arranged. 5. Safety grille (210 ', 210' ') according to one of claims 1 to 4, characterized in that the flow-through tubular elements (211', 211 ") extend into a foundation (214 ', 214") running continuously under the safety grid , 6. Security grid (210 ") according to claim 5, characterized in that the foundation (214") at least one latent heat storage (216 "), which is thermally conductively connected to the tubular element (211"). 7. Safety grid according to one of claims 1 to 6, characterized in that the at least one tubular element, which is traversed by a fluid, is embedded in a wall plate or disposed between two wall plates. 8. Safety grid (100) according to one of claims 1 to 8, characterized in that the meandering connected tubes of the tubular element (20, 30) are arranged horizontally. 9. Safety grid (210, 210 ', 210' ') according to one of claims 1 to 8, characterized in that the meandering connected tubes of the tube element (211, 211', 211 ") are arranged vertically. 10. Safety grid (210, 210 ', 210' ') according to one of claims 1 to 8, characterized in that the meandering connected tubes of the tubular element (211, 211', 211 ") are arranged horizontally. 11. Safety grid according to one of claims 1 to 10, characterized in that extending at least one signal wire through a tube member therethrough. 12. Safety grid according to one of claims 1 to 11, characterized in that the tube element is flowed through with a water-antifreeze mixture or with a brine. 13. Safety grid (300) according to one of claims 1 to 12, characterized in that parallel guided tube elements (311) are connected at opposite boundary edges of Zaungeflechts each to a manifold (312). 14. Use of the safety grid according to one of the preceding claims as a collector for a heat pump system, wherein the tube element is flowed through by a heat transfer fluid. 15. Use according to claim 13, characterized in that the tube element is flowed through with a water-antifreeze mixture or with a brine.