EP2144001B1

EP2144001B1 - Method for cleaning the brazier of a heating apparatus

Info

Publication number: EP2144001B1
Application number: EP20090425188
Authority: EP
Inventors: Sigismondo Canzian
Original assignee: CS THERMOS Srl
Current assignee: CS THERMOS Srl
Priority date: 2008-07-11
Filing date: 2009-05-15
Publication date: 2014-09-17
Anticipated expiration: 2029-05-15
Also published as: EP2144001A1; PT2144001E; ITVI20080167A1; IT1391045B1; ES2524070T3

Description

The present invention refers to, in general, a method for cleaning the brazier of heating apparatus, such as stoves or boilers.
More in particular, the invention relates to a method for cleaning the brazier of a heating apparatus according to claim 1.
In illustrative and preferred, but not limitative, embodiments of the invention, the use of biomass of any kind, such as, in particular, seeds of maize, barley, soya bean, etc., mixed with wood and/or pellet, allows to categorically cut down fuel supply costs, since the availability of these seeds is considerably higher and cheap, compared to logs wood and/or pellet.
Currently, heating apparatus are more and more popular which burn simultaneously at least two different types of solid fuel and use biomasses in general and, in particular, wood pellet mixed with other types of pressed solid fuel, such as seeds of maize, barley, soya bean, etc.
The load of the solid fuel usually occurs through a top mixing tank and one or more inner rooms, provided with tray or basket removable from the outside, by the user, for the ash collection, are further provided, laterally and/or below the brazier.
In preferred embodiments, a container is usually used, placed at a collection room located below the brazier, whose bottom presents a plurality of openings or holes, properly sized and made in order to facilitate the combustion within the brazier.
Moreover, even if minimally, from these openings the unburnt products come out, which, thus, can deposit within the container below accessible from the outside for the extraction and periodic emptying.
However, the use of a bottom surface, even if having holes and/or openings, of the collection and pouring off container leads to an inevitable accumulation of ash and other unburnt products at the inner surfaces of such openings, with the consequent clogging, with the passing of time, of portions or the whole bottom surface, which no longer allows the escape of the unburnt products from the brazier and their pouring off into the lower removable collection container.
Such a drawback is worsened by the fact that the types of pressed solid fuel such as seeds of maize, barley, soya bean, pumpkins, etc. are more difficult to ignite and produce more residual unburnt products, during combustion, compared to wood logs and/or pellet.
It follows that the partially unburnt material present in the brazier, as it accumulates, may determine the partial or total closure of the stove pipe which conveys outside the exhaust fumes, causing a potential serious danger to the user, as the air recirculation is no longer guaranteed within the room where the stove is installed.
In order to favour the passage of the unburnt material to the removable collection container, braziers having a removable bottom may also be used, which, once moved, determines the partial or total opening of the lower surface of the brazier.
However, even if, in this case, the passage of the unburnt products towards the removable collection container is facilitated, this solution increases the overall dimensions and does not guarantee a sufficient heat efficiency for an effective combustion and an adequate environment heating; indeed, a partial or full opening of the bottom of the brazier may determine the extinguishing of the flame inside the brazier, with the consequence that, in order to keep the combustion, it is necessary the use of an additional resistance, which must be turned in when the bottom of the brazier is moved.
EP 822374 describes a method for cleaning a drum-shaped brazier with rotating radial arms.
Purpose of the present invention is, therefore, to overcome the drawbacks mentioned above and, in particular, to provide a method for cleaning the brazier of heating apparatus, which allows to achieve a complete cleaning of the collection container of the accumulated unburnt material, obtaining, at the same time, the maximum heat efficiency with minimal energy expenditure and maximum user's safety.
Another purpose of the present invention is to provide a method for cleaning the brazier of heating apparatus, which presents an extreme use versatility and allows a great saving of combustive material, compared with the types of the traditional apparatus.
Other purpose of the invention is to provide a method for cleaning the brazier of heating apparatus, which avoids the need for periodic maintenances of the apparatus, by a user, and, in particular, avoids the need for a manual cleaning of the bottom of the brazier, in order to remove the residues of unburnt material which cause the occlusion thereof.
Further purpose of the invention is to provide a method for cleaning the brazier of heating apparatus, which ensures high reliability of operation, allowing, at the same time, compliance of the operating modes and electrical safety in general.
A last but not least purpose of the invention is to provide a method for cleaning the brazier of heating apparatus which is easy and economic to be produced, without the use of particularly expensive components and/or complex technologies.
Other technical features of detail are given in the subsequent claims.
In advantageous manner, the cleaning method is applicable to any type of brazier and/or boiler body and allows to keep the brazier clean for long, making the maintenance extremely quick and little frequent, compared to the traditional structures.
The management of the whole operation is entrusted to a dedicated electronic board that allows to adjust both the flow and the dosage of the solid fuels used and the moving of the brazier, in order to remove the unburnt part of fuel mixture from the inner walls of the brazier itself.
Further features and advantages of the present invention will become clear from the description that follows, relating to a preferred and illustrative, but not limiting, embodiment of the device for cleaning the brazier of heating apparatus, according to the present invention, and from the appended drawings, in which:

figure 1 is a schematic side view of a heating apparatus which uses the method for cleaning the brazier according to the present invention;
figure 2 is a schematic front view of the heating apparatus shown in figure 1 ;
figure 3 is a schematic partial section of the heating apparatus of figures 1 and 2, where the fuel load device and the combustion boiler are highlighted;
figure 4 is a front view of the boiler body of the heating apparatus of figures 1 and 2, in which the brazier and the cleaning device are highlighted;
figures 5, 6, 7 and 8 represent as many front views of the brazier in the various operating conditions.

It is stressed right now that, although the following description and the attached figures refer to a heating apparatus, such as a stove or a boiler, using two different types of solid fuel (in particular, it is described a mixture of wood pellets and other types of pressed solid fuels, more difficult to ignite or producing more waste than wood pellet, such as oily seeds of maize, soya bean, barley, pumpkin, cereals, etc. and/or biomasses of any kind), the innovative concept described in the present invention can be easily extended to any heating apparatus (stove or boiler) which uses various types of solid fuel and/or mixtures of two or more solid fuels.
With reference to the figures mentioned, an outer containment envelope of a solid fuel heating apparatus, according to the invention, is indicated with 10, which presents a series of side walls 11, a top cover 12, which defines a compartment 13 for the insertion of the solid fuel and from which a pipe portion 18 communicating with the chimney protrudes, a base 14 and a front wall 15, on which a lower boiler body 16 is made, where the combustion of the solid material takes place, associated with a lower container 17 for the collection of ash and residues produced by the combustion of the solid materials used.
According to the invention, two different types of solid fuels are inserted into the heating apparatus, through respective conduits 19, 20, which communicate with a mixing and measuring tank 26, before being conveyed to the combustion chamber 22.
The mixture of solid fuel thus produced is then introduced into the brazier 21 (where the combustion occurs) of the combustion chamber 22, obtained in the boiler body 16, by means of an Archimedean screw 23.
The brazier 21 may also advantageously be connected with the accumulation tank of the solid fuel through a flexible fitting pipe, thereby creating a thermal bridge between the combustion chamber 22 and the tank in order to prevent overheating of the latter.
In order that ignition occurs (performed by means of at least one electrical resistance) and combustion of solid fuel is kept within the brazier 21 of the combustion chamber 22, primary air is also blown, taken from the outside, through a conduct 24 made at the back of the heating apparatus, while the tangential fan 25 is used to force secondary air into the brazier 21 and thus remove the combustion products.
The tangential fan 25 is placed upstream of the brazier 21 in case the heating apparatus consists of a boiler, while is placed downstream of the brazier 21 or at the final part of fumes path, before the exhaust fitting, in case the heating apparatus consists of a stove.
The air heated by the brazier 21 flows upward and comes out into the environment, while the combustion fumes are conveyed inside the output pipe 18.
In particular, the flame of the brazier 21 for boiler spreads horizontally, while that one applied to the stove works firstly horizontally and then vertically, being sucked from the top by the fumes extraction fan.
The brazier 21 is made in the shape of a basket and presents a central axis 27, moved by an electric motor (not shown in the figures), with which are typically connected four arms 28, radially arranged and equally spaced apart each other, which extend from the central axis 27 until the surface level of the inner side walls of the brazier 21.
The brazier 21 is then moved, by means of the aforesaid electric motor, to rotate on itself, around the horizontal axis 27, so as to move, in turn, the unburnt part of the solid fuel, which enters into the brazier 21 through the opening 29, placed in communication with the supply conduct 30 attached to the mixing and measuring device 26.
According to the invention, the horizontal axis 27 and therefore the arms 28 are cyclically moved, thanks to the commands given by an electronic control board, in such a way that in the different rest positions none of the arms 28 is positioned frontally to the opening 29, in order to avoid to hamper the flow of the solid fuel (as schematically shown in figures 5, 6, 7, 8).
In this way, the unburnt part of the solid fuel is moved constantly, so that the same cannot in any way solidify on the inner wall of the brazier 21, but is forced to burn completely or to exit from the lower part of the brazier 21, falling in the container 17, in the form of ash.
Mixing and measuring of the different types of solid fuel, as well as the rotation operation of the brazier 21 for defined angles and prefixed times, are assigned to a dedicated electronic programmable board, which manages the fuel quantity and rotation timing, depending on the types and mixtures of solid fuel used.
In practice, according to the invention, it is used a brazier 21, applicable to various types of boiler body 16, which presents the ability to stay clean for long; therefore, the necessary maintenance is very quick and little frequent compared to the known technologies.
As mentioned, this allows to use at least two types of solid fuel, mixed one with each other, including the pressed solid fuels, such as oily seeds, maize seeds, pumpkin and cereals seeds in general, which are notoriously cheaper than wood and wood pellet, but are more difficult to ignite and produce more residues in the brazier.
The particular configuration of the described brazier 21 facilitates, in addition, the uniform and controlled heating of the combustion chamber 22 and, at the same time, high efficiency of the heating apparatus, which may use, similarly, wood, wood sawdust, pellet, biomasses in general, such seeds of maize, soya bean, pumpkin, cereals and/or other oily seeds, and mixtures of such materials.
From the description made the characteristics of the method for cleaning the brazier of heating apparatus, which is the object of the present invention, as well as the resulting benefits, are clear.
In particular, they are represented by the following aspects:

the solid fuel is forced to fall into a brazier;
the stove is equipped with an electronic board, which performs the function of adjusting the speed of the motors of extraction of the combustion products and the interval times for cleaning the brazier;
the brazier, rotating around itself, allows the fuel to regularly burn, avoiding scales on the surface of the brazier, even in presence of poor quality pellet;
the brazier presents a revolving horizontal axis;
ability to burn any type of pellet;
less accumulation of residues derived from the combustion, as compared to the known art;
increase of the operation autonomy of the apparatus, since the brazier is self-cleaning and, therefore, it must not be frequently cleaned;
possibility of replacing the entire brazier at the end customer, thus reducing maintenance times on site;
connection between brazier and tank through a flexible fitting, thereby creating a thermal bridge between the combustion chamber and the tank, in order to prevent overheating of the latter.

Claims

Method for cleaning the brazier (21) of a heating apparatus (10), said apparatus (10) being fed with different types of solid fuels which are measured out and mixed within an accumulation tank (26) before being conducted within the brazier (21) of a combustion chamber (22) of said heating apparatus, wherein said brazier (21) is shaped as a drum and has at least one horizontal axis (27) and a plurality of arms (28), radially arranged and equally spaced apart each other, which are connected to said horizontal axis (27) and extend from said horizontal axis (27) until a surface level of the inner side walls of said brazier (21), characterized in that said horizontal axis (27) and said arms (28) are cyclically moved for predetermined time intervals, thanks to the command given by an electronic board, in such a way that in the different rest positions, none of the arms (28) is positioned frontally to an opening (29) in order to avoid to hamper the flow of the solid fuel, wherein said opening (29) communicates with a supply conduct (30) attached to said accumulation tank (26).
Method as claimed in claim 1, characterised in that said solid fuels are forced to completely burn or to fall, in the form of ash, inside a collection container (17), which is located below the brazier (21).
Method as claimed in claim 1, characterised in that two different types of solid fuels are inserted in respective conduits (19, 20) of the heating apparatus (10), said conduits (19, 20) joining in said accumulation tank (26) and said solid fuels being further sent to said brazier (21) of the combustion chamber (22) by means of a conveyance Archimedean screw (23).
Method as claimed in claim 1, characterised in that said central axis (27) of the brazier (21) is moved by an electric motor.