EP1205711A2

EP1205711A2 - Device for an emergency forced draught, to mount on heaters and similar apparatus

Info

Publication number: EP1205711A2
Application number: EP01126928A
Authority: EP
Inventors: Vanni Dal Zotto
Original assignee: Italvas SpA
Current assignee: Italvas SpA
Priority date: 2000-11-10
Filing date: 2001-11-13
Publication date: 2002-05-15
Also published as: ITVI20000246A1; IT1315543B1; EP1205711A3

Abstract

Concerns a device for an emergency forced draught, to mount on combustion heaters or other similar apparatuses, when it is necessary to evacuate combustion fumes in emergency conditions, such as a sudden lack of electrical energy, for which reason it is necessary to ensure, for a certain period of time, a normal operation of the apparatus itself. Such a device is characterised in that it is mounted onto the extractor inserted in the piping for the combustion exhaust fumes so that, in the case of a sudden lack in electrical energy, said extractor, being still operating, makes the air circulate in the fire-box, allowing the fuel inside to burn until it has run out and allowing the fumes to be evacuated in a normal manner through the chimney.

Description

The finding regards a forced draught device for mounting onto combustion heaters or above other apparatuses in which it is necessary to evacuate exhaust fumes in the case of an emergency.
Current combustion heaters, in particular those which use wood pellets as a fuel, are usually mounted with extractors and ventilators which promote the circulation of primary and secondary air and ensure the evacuation of the exhaust fumes.
Therefore, it is easy to imagine how, in the case of a sudden lack of electrical energy, the operation of the heater is defective; in particular, the fumes are no longer drawn out of the combustion chamber. These fumes, through the slits on the body of the heater, which, in normal operating conditions have the function of circulating the air, spread in the room creating discomfort and danger for the people in the heated room.
A purpose of the present finding is that of realising a device which, in the case of a sudden lack in electrical energy, ensures, for a certain additional period of time, a normal operation of the heater.
Specifically, the device according to the finding is mounted onto the extractor inserted in the exhaust piping for the combustion fumes so that, in the case of a sudden lack in electrical energy, said extractor, being still operating, makes the air circulate in the fire-box, allowing the fuel contained inside to burn until it has run out and allowing the fumes to be evacuated in a normal manner through the chimney.
Substantially, the device according to the finding is placed in contact with the rotating shaft of the fumes extractor and through an electromechanical transmission makes said shaft rotate, also when there is a lack of electrical energy supplied by the grid.
Constructively, the device according to the finding is essentially made up of two low-voltage electrical motors.
A first electrical motor, through a mechanical regulator, consisting, for example, of a cam and of a spring which work against each other, makes a bracket rock, upon such a bracket being applied a second electric motor, equipped with a rotational motion transmission member, such as a pulley which is alternatively placed away from or in contact with the rotating shaft of the extractor, according to the two operating conditions of the heater: normal and emergency;
in particular the entire group is mounted onto a single base plate.
The device is completed with a sensor, such as a limit switch, activated by the rocking of the bracket, with a reserve battery and also with an electronic control circuit.
In conditions of the normal operation of the heater and thus with the device according to the finding in rest state, the two motors remain switched off and the cam mounted on the first motor, overcoming the resistant of the spring, keeps the bracket tilted in such a way that the second motor's pulley is taken away from the rotor of the extractor, which operates normally being fed from the power grid.
In operation, when, for various reasons, the feed of electrical energy from the grid is interrupted, the reserve battery activates, which feeds the two aforementioned motors: the first motor makes the cam angularly rotate, which disengages the bracket which, pulled by the spring, angularly rotates on its pin, so as to take the second motor's rotating pulley into contact with the shaft of the extractor which has stopped, making it rotate once again.
The angular movement of the bracket is detected by a sensor, such as a limit switch, which opens the power supply circuit of the first motor stopping it, so as to prevent the cam from moving back into contact with the same bracket.
When the supply from the power grid returns, the first motor, once again fed by the reserve battery, goes back into operation and, through the rotation of the cam, takes the bracket back to its initial position, corresponding to the disattachment position of the second motor's pulley from the extractor's shaft.
After this the reserve battery is disactivated and the entire device, inactive, remains in rest state until the next accidental interruption of the supply from the power grid.
The finding shall now be better described with reference to a particular embodiment thereof, given purely as a nonlimiting illustrative example, with the help of the attached drawings, where:

fig. 1 (Tav. I) represents a perspective view of a heater to which the device according to the finding is attached;
fig. 2 represents a perspective view of the device according to the finding;
figures 3A-3B and 4A-4B (Tav. II) represent front and rear views of the device according to the finding in rest and emergency state, respectively.
figures 5A-5B and 6A-6B (Tav. III) represent orthogonal views, front and plan, respectively of the device according to the finding, in rest and emergency state, respectively.

As can be seen in fig. 1, the device 1 according to the finding is applied onto the exhaust fume extractor 2 of a heater 3.
As can be seen better in fig. 2, the device 1, placed adjacent to the flywheel 4 of the extractor's shaft, consists of an electric motor 5, equipped with a cam 6, of an electric motor 7 equipped with a pulley 8, of a bracket 9, rocking about a pin 10 and pulled by a counterspring 11 and of a limit switch 12; the whole thing is supported by a plate 13 which is anchored, through the screws 14, to the fixed structure.
In operation, as can be seen is the succession of "A" figures, in the device 1 according to the finding, when it is in the rest state, i.e. not intervening, the two motors 5 and 7 are shut off and the cam 6, overcoming the resistant of the spring 11, keeps the bracket 9 rotated so that the pulley 9 is disattached from the surface 15 of the flywheel 4.
Then, as can be seen in the succession of "B" figures, when the supply of electrical energy from the grid is interrupted, the reserve battery, not represented, activates, which feeds the two motors 5 and 7.
The motor 5 makes the cam 6 angularly rotate, which disengages the bracket 9 which, pulled by the spring 11, angularly rotates on its pin 10, so as to bring the rotating pulley 8 of the motor 7 into contact with the surface 15 of the flywheel 4 of the extractor, which has stopped, making it rotate once again.
The angular movement of the bracket 9 is detected by the limit switch 12, which opens the power supply circuit of the motor 5 bringing it to a halt and thus prevents the cam from moving back into contact with the bracket itself.
When the electrical supply from the power grid returns the motor 5, once again fed from the reserve battery, goes back into operation and, through the rotation of the cam 6, takes the bracket 9 back to the initial position, corresponding to the disattachment position of the pulley 8 of the motor 7 from the surface 15 of the flywheel 4.
After this, the reserve battery is disactivated and the entire device, rendered inactive, remains in the rest state until the next accidental interruption of the electrical energy from the grid, as represented in the "A" figures.
Obviously, different embodiments from the one illustrated are possible, depending upon the components used, without departing from the scope of protection of the claims, defined hereafter.

Claims

DEVICE FOR AN EMERGENCY FORCED DRAUGHT, TO MOUNT ON HEATERS AND SIMILAR APPARATUSES, when it is necessary to evacuate the combustion fumes in emergency conditions, such as a sudden lack of electrical energy, for which reason it is necessary to ensure, for a certain period of time, a normal operation of the apparatus itself.
said device characterised in that
it is mounted onto the extractor inserted in the piping for the combustion exhaust fumes so that, in the case of a sudden lack in electrical energy, said extractor, being still operating, makes the air circulate in the fire-box, allowing the fuel inside to burn until it has run out and allowing the fumes to be evacuated in a normal manner through the chimney.
DEVICE FOR AN EMERGENCY FORCED DRAUGHT, according to claim 1, characterised in that it is placed in contact with the rotating shaft of the fumes extractor so that, through an electromechanical transmission, it makes said shaft rotate, also when there is no electricity supply from the grid.
DEVICE FOR AN EMERGENCY FORCED DRAUGHT, according to claims 1 and 2, characterised in that it comprises two low-voltage electric motors, a first motor, through a mechanical regulator, making a bracket rock, upon which a second electric motor is applied, equipped with a rotary motion transmission member, said member being alternatively placed away from or in contact with the extractor's rotating shaft, according to the two operating conditions of the heater: normal and emergency, respectively.
DEVICE FOR AN EMERGENCY FORCED DRAUGHT, according to claims from 1 to 3, characterised in that it is controlled through a sensor, activated by the rocking movement of the aforementioned bracket.
DEVICE FOR AN EMERGENCY FORCED DRAUGHT, according to claims from 1 to 4, characterised in that it is fed by a reserve battery.
DEVICE FOR AN EMERGENCY FORCED DRAUGHT, according to one or more of the previous claims, applied adjacent to the flywheel (4) of the exhaust fume extractor (2) of a heater (3),
characterised in that it comprises an electric motor (5), equipped with a cam (6), as well as an electric motor (7), equipped with a pulley (8)and a further bracket (9), rocking about a pin (10) and pulled by a counterspring (11) and, finally, a limit switch (12), the whole thing being supported by a plate (13).
DEVICE FOR AN EMERGENCY FORCED DRAUGHT, according to one or more of the previous claims, characterised in that, when it is in rest state, i.e. not intervening, the two motors (5, 7) are shut off and the cam (6), overcoming the pull of the spring (11), keeps the bracket (9) rotated so that the pulley (8) is disattached from the surface (15) of the flywheel (4).
DEVICE FOR AN EMERGENCY FORCED DRAUGHT, according to one or more of the previous claims, characterised in that, when the electricity supply from the grid is interrupted, a reserve battery kicks in, which feeds the two motors (5, 7), the motor (5) making the cam (6) angularly rotate, which disengages the bracket (9) which, pulled by the spring (11), angularly rotates on its pin (10), so as to bring the rotating pulley (8) of the motor (7) into contact with the surface (15) of the flywheel (4) of the extractor, making it rotate once again.
DEVICE FOR AN EMERGENCY FORCED DRAUGHT, according to claim 8, characterised in that the angular displacement of the bracket (9) is detected by the limit switch (12), which opens the power supply circuit of the motor (5), bringing it to a halt.
DEVICE FOR AN EMERGENCY FORCED DRAUGHT, according to claims 8 and 9, characterised in that, when the electrical energy supply from the grid returns, the motor (5), once again fed from the reserve battery, goes back into operation and, through the rotation of the cam (6), brings the bracket (9) back to the initial position, corresponding to the disattachment position of the pulley (8) of the motor (7) from the surface (15) of the flywheel (4).