Patent Application
20120210998
Applicant claims priority under 35 U.S.C. §119 of Italian application No. MI2011A000156 filed Feb. 4, 2011 the disclosure of which is incorporated by reference.
The present invention relates to a liquid hydrocarbon or bioethanol heating appliance.
More in particular, the present invention relates to a heating appliance shaped as a fireplace for household environments and in general but not exclusively, for interiors, apt to be variably positioned in various zones of the rooms as it does not require the connection to a flue for conveying the combustion gases outwards.
Heating appliances of this kind, wherein the combustion of bioethanol or of an optional similar fuel such as kerosene occurs at the air-vapour mixture state of the same fuel, have long been known; since the combustion of a minimum amount of bioethanol produces very low levels of toxic gases, such appliances may be easily used in closed rooms and without flues for a given number of hours, although aerating the room is recommended. In addition to the heating effect, the same appliances also represent furnishing elements with ornamental features of a various nature. For safety purposes, with special reference to the fire hazard of the fuel contained within the appliance tank, as well as with reference to the accidental overturning of the entire structure that is not secured to the floor, the known subject heating appliances have been provided with devices apt to prevent the entire amount of fuel equal to the tank capacity to be arranged within the burner.
A first embodiment of bioethanol appliances, in fact, provided for the entire amount of fuel required for the expected operating hours to be arranged within the burner, so that the flame burnt by combustion of the mixture of air-vapour, the latter floating on the whole flammable liquid. In this case, a collision or the violent movement of the fireplace as well as the accidental overturning thereof, caused the fuel overflow with the very likely risk of a fire. Subsequent embodiments of bioethanol appliances or fireplaces led to separate the tank from the burner; in the latter, the amount of fuel is small whereas the tank located away from the burner contains most of the flammable liquid.
The feeding is carried out by pressure difference between closed tank and atmospheric pressure; in particular, when the combustion decreases the liquid level within the burner bringing it below the feeding hole, some air bubbles enter into the tank, altering the pressure balance, until the liquid flows from the tank into the burner and restores the original level.
However, also this solution does not offer full safety guarantees against the occurrence of possible fires, since the tank liquid always communicates with the combustion chamber; since the liquid level within the tank is very high compared to the burner, in the event of a failure of the levelling system the liquid present into the tank may spill out of the combustion chamber and propagate onto the floor. This may happen, for example, due to a transfer of air into the tank, with considerably serious consequences.
A further drawback of the known subject heating appliances wherein tank and burner are separate relates to the loading of fuel into the tank.
A first solution provides for a removable tank, which however exhibits the drawback of a possible damage of the coupling components the same tank is provided with during the movement that takes place during the fuel loading step.
The same tank may be damaged during such operation, with the risk of progressively leaking the liquid once placed and left unattended.
According to another known solution, the tank is attached to the heating appliance. In this case, the filling is often difficult and the tank placement is anything but optimal since it is close to the burner. Moreover, fixed tanks are provided with a gravity filling hole, with the consequence that the hazardous spilling of the liquid fuel in the filling step is highly likely.
A further drawback found in the known subject heating appliances relates to the fuel dispensing to the burner; such dispensing, in fact, is usually based on pressure balances and conduit sizes that may easily alter under certain conditions, such as for example if the appliance is moved or arranged on a surface that is not perfectly flat.
A bioethanol heating fireplace is known from Fr 2 927 149, wherein the fuel tank is arranged away from the burner zone for safety reasons; therefore, close to the flame there is a minimum amount of fuel, fed by a pump. However, this solution exhibits several drawbacks, for example related to the fact that the fuel within the tank heats and develops flammable vapours that could propagate despite the provision of a siphon device, especially suitable for the liquid. Moreover, this solution does not provide for safety systems apt to prevent accidental spilling of the fuel in the event of collisions and/or sudden movements. The risk resulting from a possible failure of the level detectors should also be contemplated, as it may lead the pump to feed the entire fuel of the tank into the combustion chamber. This would cause the hazardous overflow of a considerable part of the fuel outside, considering that the volume of the latter is significantly larger than the capacity of the combustion chamber.
A similar bioethanol heating appliance is also known from Fr 2 931 538, which exhibits the same considerable drawback related to the possible failure of the fuel level detectors.
Another drawback, also found in the solution of the above French patent as well, relates to the fuel filling system; even in the presence of a gate apt to lock the operation of the pump that fills the burner with fuel, there are no means that prevent the fuel from being directly poured into the burner when the appliance is switched off. This implies considerable hazards since the burner and the surroundings thereof may still be very hot even though the appliance has previously been switched off.
The object of the present invention is to obviate the drawbacks mentioned hereinabove.
More in particular, the object of the present invention is to provide a liquid hydrocarbon or bioethanol heating appliance wherein the flammable liquid present into the tank is suitably and constantly isolated from the combustion chamber, except during the feeding steps when the appliance is actually switched on.
A further object of the invention is to provide an appliance as defined above wherein the fuel tank filling is carried out easily and under totally safe conditions.
A further object of the invention is to provide a bioethanol heating appliance wherein the operation of direct filling of the fuel into the tank is prevented when the appliance is switched off.
Last but not least, an object of the invention is to provide a heating appliance wherein the dispensing of the fuel required for feeding the burner takes place with very high accuracy and safe from hazards of any kind.
A further object of the invention is to provide the users with a heating appliance apt to ensure a high level of resistance and reliability over time, also such as to be easily and inexpensively constructed.
These and yet other objects are achieved by the liquid hydrocarbon or bioethanol heating appliance of the present invention according to the main claim.
The construction and functional features of the heating appliance of the present invention shall be better understood from the following drawing tables showing a preferred and non-limiting embodiment thereof, and wherein:
With initial reference to
Said structure is defined by two opposite side bands 12 with vertical development, connected to each other at the top by a crosswise panel 14 and delimiting a base 16 at the bottom which incorporates the combustion chamber, the fuel tank and the functional components that shall be described hereinafter.
The area delimited by bands 12, by the crosswise panel 14 and by base 16 is partly screened, on opposite front and back fronts, by respective sheets 18 of a transparent material such as glass, crystal or the like.
The exposed top front of base 16 is centrally provided with an opening 20, preferably having a rectangular shape, wherein the longer sides extend parallel to the front and back edges of the same base; opening 20 defines the combustion chamber mouth wherefrom the flame develops and which may be closed by one or more separators, described hereinafter.
As schematically shown in
Opening 20 may be screened by means of opposite separators 32, the larger or smaller opening whereof causes a corresponding heating effect. Separators 32 are kept closed, that is, in a reciprocal approach that screens the combustion chamber 24, by helical springs 34, whereas they are activated to open up or reciprocally separate by means of an electrical motor 36, for example of the magnetic stepping type, cooperating with a rod 37 coupled to racks 39. During the appliance operation, that is, with flame on, the electrical motor 36 is always tensioned to keep separators 32 open; otherwise, the helical springs 34 compress up to automatically return packet-wise and close separators 32 causing the switching off of flame “F” by choking, that is, lack of combustible.
In order to keep a low but sufficient and constant level of fuel within the combustion chamber 24, to minimise the hazards resulting from an accidental spilling, it is contemplated that valve 30 automatically opens and closes upon reaching predefined minimum and maximum levels of the same fuel within said chamber. The level detection is for example carried out by one or more probes 38 preferably arranged into the safety valve 28, or by a magnet detector or by one or more metal electrodes seated within the combustion chamber 24, as per page 7; the consequent activation of valve 30, which allows the liquid passage from tank 22 to the combustion chamber 24 for restoring the level established within the same chamber is advantageously managed by an electronic control unit 40 supplied by a rechargeable battery. Besides the advantage of keeping a low fuel level within the combustion chamber 24, this solution allows keeping valve 30 mainly closed; in fact, it opens up for a few seconds only, required to restore the contemplated liquid level within the combustion chamber 24, causing both a considerable reduction of the battery energy consumption and a significant increase in the overall safety, as it keeps tank 22 normally separated from said combustion chamber 24.
In a first embodiment solution, the fuel that drains from tank 22 to the combustion chamber 24 crosses a solenoid valve 42 associated to a level adjustment device 44 provided with a float 46. Said device 44 consists of a metal body comprising a conduit 48 which connects it on the one side to tank 22 and on the other side to the burner or combustion chamber 24; device 44 defines a measurement chamber 50 with vertical development, wherein float 46 is arranged. A rod 54 is vertically attached to float 46, made of a material having suitable chemical resistance features, and it moves integrally with the same float. Through such rod, which protrudes at the top from the level adjustment device 44, it is possible to show to the outside the indication of the minimum and maximum fuel levels desired within the combustion chamber 24. Such levels, moreover, are preferably subject to preventive calibration upon the manufacture or testing of appliance 10. Electronic level detectors of the known type (not shown) are installed on the top side of the measurement chamber 50, connected with the electronic control unit 40 that detects the minimum and maximum level signals of rod 54 connected to float 46. Also in this embodiment, the solenoid valve 42 is normally closed and this prevents the fuel passage between tank 22 and the combustion chamber 24. The solenoid valve 42 thus deactivated in advance also eliminates useless electrical energy wastes. Moreover, the fuel level within the combustion chamber 24 is always reduced to the minimum, with the consequence that no hazardous combustions may occur, not even in the event of overturning of appliance 10. In fact, the electronic control unit 40 receives the minimum level signal from the electronic detectors located within the measurement chamber 50 and accordingly sends a pulse to the solenoid valve 42 which temporarily opens up and lets the fuel drains from tank 22 to the measurement chamber 50 of device 44 and thereby to the combustion chamber 24. Conversely, when the predetermined maximum liquid level is reached within chamber 50, a new pulse is sent by the electronic control unit 40 to the solenoid valve 42, which instantly closes and interrupts the fuel passage.
In a second and alternative construction solution, the fuel that drains from tank 22 to the combustion chamber 24 crosses the solenoid valve 42 associated to a conduit. In the bottom portion of the combustion chamber 24 there are installed one or more metal level electrodes 90 of the known type, connected with the electronic control unit 40 which detects the minimum and maximum level signals. Such levels, moreover, are preferably subject to preventive calibration upon the manufacture or testing of appliance 10. Said metal detectors act as fuel level sensors based on the known physical principle of the electrical conductivity variation in the presence of elements having different values of the same: in particular, the voltage value detected by the electronic control unit 40 at the metal electrodes differs according to whether said electrode is in dry condition or wetted by the fuel. When the electronic control unit 40 receives the minimum level signal from the electronic detectors arranged within the combustion chamber 24, that is, when the minimum electrode or electrodes are not wetted by the fuel, it accordingly sends a pulse to the solenoid valve 42 which temporarily opens up and lets the fuel drain from tank 22 to the combustion chamber 24. Conversely, when the predetermined maximum level of liquid in the combustion chamber 24 is reached, that is, when the maximum electrode or electrodes are wetted by the fuel, a new pulse is sent by the electronic control unit 40 to the solenoid valve 42, which instantly closes up and interrupts the fuel passage. Also in this embodiment, the solenoid valve 42 is normally closed and this prevents the fuel passage between tank 22 and the combustion chamber 24. The solenoid valve 42 thus deactivated in advance also eliminates useless electrical energy wastes. Moreover, the fuel level present within the combustion chamber 24 is always reduced to the minimum, with the consequence that no hazardous combustions may occur, not even in the event of overturning of appliance 10.
According to a further advantageous feature of the invention, the filling of tank 22 is carried out by a quick coupling valve consisting of two complementary male and female parts, for example of the type known on the market as PLC series by Colder Products Company. A valve of this type allows coupling and uncoupling with the concurrent immediate opening/closing of the male and female elements without the need for flow intercepting taps. The two male-female elements, indicated with reference numerals 56 and 58 in
A float 52 arranged within tank 22 is advantageously provided for causing the automatic closing of the feeding conduit 62 once the predetermined filling level into tank 22 has been reached. Said tank is provided with a venting valve 64 that facilitates the topping up operation. For safety purposes, it is envisaged that the loading or top up of tank 22 are only possible when the appliance is switched off and to this end, a microswitch of the known type is arranged at a door 66 that closes the inlet of conduit 62 and screens component 58 of said valve. Said microswitch is connected with the electronic control unit 40 which, receiving the electrical signal for opening door 66, causes the closing of separators 32, deactivating motor 36, thereby interrupting the combustion.
As an alternative or in addition, a tilting wall 23 interacting with a similar microswitch connected with said control unit may be provided for the same purpose on the access front of the filling valve.
The venting valve 64 also has the function of preventing the occurrence of overpressures within tank 22 resulting, for example, from high room temperatures. Moreover, said valve prevents the accidental leaking of fuel in the event of tilting or overturning of tank 22.
According to a further advantageous feature of the invention, the combustion chamber or burner 24 is made of a metal structure with multiple sectors connected to each other, which in particular define a top zone wherein the combustion takes place and a bottom zone wherein the combustible liquid is collected in the event of accidental overturning of the heating appliance.
In particular, as is seen in
In the event of accidental and even partial overturning, the signal sent by the inclination sensor also determines the immediate interruption of the fuel feeding of tank 22 to the level adjustment device 44 that feeds the combustion chamber 44. It is advantageously envisaged that the maximum fuel amount present within tank 22 is such as to be distributed and be contained within the combustion chamber 24, levelling according to the principle of communicating vessels in the event of a failure of the dispensing system, thus preventing any outward leaks. Moreover, for operating safety purposes, the heating appliance of the present invention may be provided with a CO2 detector interacting with the control unit 40 and with a timer apt to automatically switch off the same appliance when a given number of operating hours is reached. Moreover, the appliance may be provided with a container for diffusing fragrances in the environment, arranged adjacent the combustion chamber or in other suitable position.
The heating appliance of the present invention is advantageously made in the shape of a fireplace, as shown in
The heating appliance of the present invention ensures optimal safety levels since the tank fuel is constantly isolated from the combustion chamber and the periodical filling of the same tank is carried out in an easy, ergonomic manner and for higher safety, with blown out flame only.
Under this condition of non operating appliance, moreover, it is in any case impossible to directly pour the fuel into the burner since separators 32 are closed, to the advantage of safety.
The fuel dispensing into the burner, moreover, takes place with extreme accuracy and away from spilling or other types of hazards; even in the event of an accidental overturning of the appliance, the fuel does not come out of the burner or the tank as it is collected within the safety chamber.
A further advantage is the possibility of customising the appliance from the aesthetic point of view, thanks to the interchangeability of the side bands 12 and of the top panel 14. The same appliance may further be provided with wheels that facilitate the movement thereof. Although the invention has been described hereinbefore with particular reference to an embodiment thereof made by way of a non-limiting example, several changes and variations shall clearly appear to a man skilled in the art in the light of the above description. The present invention, therefore, is intended to include any changes and variations thereof falling within the spirit and the scope of protection of the following claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| MI2011A000156 | Feb 2011 | IT | national |
