DE202012006361U1 - Safety device for an exhaust air system - Google Patents

Abstract

A safety device for an exhaust air system - comprising a first module (10) having at least one sensor and sensor-responsive means for generating an enabling signal, - a second module (20) having switching means similar to that of the first one Module (10) responsive release signal responsive and the electrical power supply of the exhaust system switches, characterized in that - the activation signal generated by the first module (10) is a series of signals at predetermined regular time intervals and - the second module (20) comprises a circuit which disconnects the exhaust air system in a first time period, when the activation signal is absent, wherein the first time period is longer than the intervals of the signals of the activation signal.

Description

The invention relates to a safety device for an exhaust air system, by means of which it is ensured that in the interior of a building by the exhaust air system, no excessive negative pressure is created by the example, the deduction of a fireplace is hindered. The safety device includes a first module having at least one sensor and sensor-responsive means for generating an enabling signal, and a second module having switching means responsive to the enabling signal generated by the first module and the electrical power supply of the exhaust system on.

Out DE 103 16 571 is such a safety device for an exhaust air system is known in which by means of a differential pressure detecting device, the pressure difference inside and outside a building is determined and the fan power of an exhaust air system is controlled in dependence on the detected differential pressure. The fan of the exhaust air system is switched off when the internal pressure falls below the external pressure below a threshold value of 4 Pa. A similar security device is off EP 1 382 914 In this case, the first module with the pressure sensors for air pressure measurement is wirelessly connected to the second module, which contains the evaluation device.

Out DE 102 28 131 a safety plug-in device for an exhaust air system is known in which the electrical connection to the exhaust system is interrupted when control signals from a Zuluftsystem, z. As a window, indicate that this is not open.

Out DE 102 04 264 is a fuse monitoring of fireplaces is known, which measures the air pressure inside the fireplace and in the installation room, forms the difference of the air pressure values and operates the fireplace, a safety device or an alarm when exceeding a limit value.

Out WO 2007/134829 a switching device for extractor hoods is known, which is switchable by means of a deflecting flap between an exhaust air operation and a recirculation mode. The exhaust air operation is only possible if sufficient ventilation in the form of an open window is available.

These known safety devices are closed systems that are not expandable and can not be adapted to the particular situation.

The invention has for its object to provide a safety device of the type mentioned, which is universally applicable. This object is achieved by a safety device having the features of claim 1.

The first module has as a sensor, for example, a pressure sensor, a differential pressure sensor, a reed sensor or a temperature sensor. The signal from the sensor is processed in the first module, and it is used to determine whether the exhaust air system can be safely operated. If the processing leads to the result that the exhaust air system can be operated safely, then in the first module the enabling signal is generated. The release signal thus indicates that the exhaust air system can be safely operated.

The enabling signal is a series of individual signals with a predetermined repetition frequency. The individual signals are identical and can be repeated, for example, every 10 seconds. The enable signal is thus independent of the type of sensor used in the first module.

The second module has a switching device, which preferably responds to the enable signal generated by the first module in such a way that it switches the electrical power supply of the exhaust air system or at least the fan motor when the unlock signal is obtained and that the exhaust air system or its Fan motor de-energized within a first period of time, when the enable signal is absent. This first time span is longer than the time intervals of the individual signals of the enable signal and is preferably 30 s.

In many cases, the sensor is a differential pressure sensor, which determines the difference between the external pressure and the internal pressure. In rooms with open fire pits, the internal pressure in the room may be a maximum of 4 Pa below the external pressure according to the building regulations (firing regulations). If the internal pressure is lower, no exhaust air system, for example an extractor hood, may be used in this room. This is to avoid that is sucked from the exhaust system flue gas from the fireplace in the room.

In a preferred embodiment, the signal of the differential pressure sensor is already evaluated in the first module and thereby compared with the threshold value. As a result, the enable signal contains only the information as to whether the difference between the external pressure and the internal pressure is above or below the threshold value. The enable signal is therefore only a yes / no signal. It does not reflect the value of the pressure or differential pressure.

As a result, the system can easily be extended to include additional sensors for the Example show the operation of the fireplace or contain the information whether a window is open or closed. Viewed from the second module, all these further modules behave in the same way, namely they send an enabling signal in the form of a chain of individual signals at predetermined regular intervals, when the exhaust air system can be safely operated. If the first module contains a differential pressure sensor, the enable signal is sent when the differential pressure is below the threshold. In contrast, if the first module has a magnetic contact in the form of a reed sensor, the enable signal is sent when the reed sensor indicates that the window is open. These two forms of the first module are alternatively used in practice. In addition, the third module can be used with the temperature sensor that sends the enabling signal when the temperature sensor indicates a temperature of, for example, below 40 ° C, which is equivalent to the fact that the fireplace is not in operation.

In particular, if the first module has a differential pressure sensor, the generation of the enable signal is not immediately canceled when the differential pressure above 4 Pa, but the enable signal is then still for a second period of time, for example 130 s generated. This is intended to ensure that the release signal is not terminated, for example, by the opening of a door or a gust of wind. Only if after the second period, z. B. after 130 s, the differential pressure is still above 4 Pa, the enable signal is no longer generated.

The signal transmission from the first module to the second module can take place via a cable or wirelessly.

Further preferred embodiments are the subject of the dependent claims.

An embodiment of the invention will be explained in more detail with reference to the drawing. Show it:

1 schematically the individual components of a safety device for a ventilation system with wireless signal transmission, and

2 the individual components a safety device with wired signal transmission.

In the 1 shown safety device for an exhaust system 22 has a first module 10 on, in which two differential pressure sensors 12 are included. For safety reasons, the differential pressure sensor 12 executed twice. Every differential pressure sensor 12 has a first entrance 13 and a second entrance 14 , The first module 10 is usually mounted in the room from which the exhaust system sucks the air. The first entrance 13 then flows into the immediate vicinity of the first module 20 while the second entrance 14 each via a hose 15 opens out into the exterior of the building. At the two differential pressure sensors 12 Therefore, both the internal pressure of the room in which the exhaust air system, for example the extractor hood, is located, as well as the external pressure of the building in question.

According to the firing ordinance, the differential pressure must not exceed 4 Pa. The measured differential pressure is therefore determined by means of one in the first module 10 comparison circuit compared with a threshold of 4 Pa. As long as the internal pressure applied via the first input is not more than 4 Pa below that at the second input 14 adjacent external pressure of the building, sends the first module 10 via an integrated transmitter an enabling signal to a second module 20 that supplies the power to the ventilator of the exhaust system 22 switches freely. The enable signal is a series of short individual signals at intervals of 10 seconds.

The second module 20 contains a receiver for that of the first module 10 emitted release signal. About connections 24 , a potential-free contact, the control of the exhaust air system takes place. As long as the first module 10 sends the enable signal, one switches in the second module 20 provided switching device to the fan motor of the exhaust air system 22 leading line free so that the fan motor is running. This switching device of the second module 20 will also release the line for a first 30 second period after the second module 20 the last single signal of the activation signal from the first module 10 had received. If there is no release signal from the second module for longer than the first time period of 30 seconds 20 received, the switching device switches the line to the fan motor de-energized, so that the exhaust air system 22 no more air sucks. The control of the exhaust air system 22 This is done in response to the enable signal from the first module 10 to the second module 20 is sent.

To compensate for short-term pressure fluctuations, for example by opening a door or as a result of gusts of wind, the release signal from the first module 10 sent for a second time period of about 130 seconds after the internal pressure is more than 4 Pa below the outside pressure. Overall, the fan continues to run for at least 160 seconds after the differential pressure has risen above 4 Pa.

If the safety device serves to ensure a sufficient draft of a fireplace, then as the third module 30 a temperature sensor module can be used which has a temperature sensor 32 and contains a transmitter. The temperature sensor 32 For example, it can be mounted on the flue pipe of the fireplace and control the transmitter so that it sends the enable signal to the second module 20 sends when the temperature sensor 32 on the flue pipe measures a temperature of less than 40 ° C. The third module 30 generated release signal also consists of a chain of individual signals at intervals of 10 seconds.

Through the third module 30 is achieved that the exhaust system 22 regardless of a difference in internal and external pressure works when the fireplace is not in operation.

The first module 10 can instead of the differential pressure sensor 12 also a position sensor, z. B. a reed sensor 16 , which determines if a window in the room of the exhaust system is open. The transmitter of the first module is from the reed sensor 16 controlled so that it sends the enabling signal, if and as long as using the reed sensor 16 it is determined that the window is open. This ensures that the exhaust system 22 always working with the window open, regardless of the detected differential pressure. For a safe operation of the fireplace is always possible with sufficiently open window, regardless of the detected differential pressure.

At the in 2 the safety device shown, the transmission of the enable signal from the first module takes place 10 to the second module 20 over a cable 18 , The first module 10 So has a cable transmitter and the second module 20 a cable receiver. The second module 20 has a floating signal input 26 to which the release signal of the first module 10 is transmitted. The first module 10 works with either a differential pressure sensor or a magnetic switch (reed sensor) to generate the enable signal.

LIST OF REFERENCE NUMBERS

10

first module

12

Differential pressure sensor

13

first entrance

14

second entrance

15

tube

16

Reed sensor

18

electric wire

20

second module

22

exhaust system

24

connections

26

signal input

30

third module

32

Temperature Sensor

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 10316571 [0002]
• EP 1382914 [0002]
• DE 10228131 [0003]
• DE 10204264 [0004]
• WO 2007/134829 [0005]

Claims (8)

Safety device for an exhaust air system - with a first module ( 10 ) having at least one sensor and a sensor-responsive device for generating a release signal, - with a second module ( 20 ), which has a switching device which is connected to that of the first module ( 10 ) activates and activates the electrical power supply of the exhaust air system, characterized in that - that of the first module ( 10 ) is a series of signals at predetermined regular time intervals and - that the second module ( 20 ) has a circuit which de-energizes the exhaust system within a first period of time when the enable signal is absent, wherein the first time period is longer than the intervals of the signals of the enable signal. Safety device according to claim 1, wherein the sensor is a pressure sensor ( 12 ) for generating a pressure signal, the first module ( 10 ) has a comparison device for comparing the pressure signal with a threshold value and the enable signal is generated in dependence on the comparison. Safety device according to claim 2, wherein the first module ( 10 ) two pressure sensors ( 12 ) and the pressure signal indicates the difference in the pressure values that are output by the pressure sensors ( 12 ) be determined. Safety device according to claim 1, wherein the sensor is a position sensor which provides a signal when a window of the space is opened from which sucks the exhaust air system. Safety device according to one of the preceding claims, wherein the predetermined regular intervals of the signal series of the enable signal amount to about 10 seconds and the first time period after which the switching device deenergizes the exhaust air system is about 30 seconds. Safety device according to one of claims 1 to 3 or 5, wherein the first module ( 10 ) within a second period of time after the pressure value has exceeded the threshold, generates the enable signal. The security device of claim 6, wherein the second period of time is about 130 seconds. Safety device according to one of the preceding claims, wherein a third module ( 30 ) is provided, which measures the temperature within a fireplace or the flue pipe of a fireplace, this temperature is compared with a threshold and also by means of a transmitting device, the enabling signal to the second module as long as the measured temperature is below the threshold.

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