Patent Application
20170254530
This application claims priority to Australian Patent Application No. 2016900778, filed on 2 Mar. 2016, wherein the specification and contents of which is hereby incorporated herein by reference in its entirety.
Field of the Invention
Embodiments of the invention generally relate to a baffle plate for use in a solid fuel heater. In particular, the invention relates to a battle plate having a plurality of air inlets disposed on a front surface that are in communication with a secondary air source so as to more efficiently and effectively combust the emissions from the combustion of material in a primary combustion zone in a heater.
Description of the Related Art
When wood, or other similar organic matter, burns in a slow combustion wood heater, it goes through several stages of combustion. During the pyrolysis stage as the cellulose matter changes to charcoal there is a lot of gases released otherwise known as smoke. To produce a low emission wood heater, these gases need to be burnt off so as to reduce the amount of smoke or un-combusted gaseous material from leaving the wood heater so as to reduce the heaters emissions.
Current wood heaters in the market have various methods of introducing oxygen into the gaseous combustion zone above the burning logs, otherwise known as secondary air. This is generally via a burn tube which is a 25-30 mm diameter tube extending from one side of the firebox to the other with a row of small holes introducing oxygen into the firebox. Primary air is often brought in at the front of the heater, down the glass and into the base of the fire.
Alternatively, or additionally depending on the model heater, additional oxygen is introduced via a row of holes in the rear of the firebox directly into the main combustion zone of the heater. In yet other examples, a catalytic converter is included into the baffle system with the aim of capturing and combating un-combusted products.
For combustion of the un-burnt gases to occur, the temperature must be 600-650° C. and additional oxygen should be introduced into the combustion chamber as this is typically an oxygen poor environment with most of it being used in the main combustion zone.
If the oxygen is not preheated sufficiently, as it enters the firebox it will lower the temperature and the gases will not ignite for complete combustion, resulting in the gases escaping through the flue thus increasing the heaters emissions.
It is an object of one or more embodiments of the invention to overcome, or at least substantially ameliorate, the disadvantages and shortcomings of the prior art.
Other objects and advantages of one or more embodiments of the invention will become apparent from the following description, taking in connection with the accompanying drawings, wherein, by way of illustration and example, at least one embodiment of the present invention is disclosed.
According to the present invention, although this should not be seen as limiting the invention in any way, in at least one embodiment there is provided a baffle plate for use in a solid fuel combustion appliance, the baffle plate having a main body section, the main body section having a front face and a back face, at least one curved secondary air outlet chambers having a plurality of secondary air outlet openings thereon and at least one secondary air inlet chamber fluidly connected to the at least one curved secondary air outlet chamber to provide air to the at least one curved secondary air outlet chamber.
In one or more embodiments, there are at least two curved secondary air outlet chambers.
In one or more embodiments, the at least two curved secondary air outlet chambers are substantially parallel with respect to each other.
In one or more embodiments, the curved secondary air outlet chambers are convex shaped.
In one or more embodiments, the curved secondary air outlet chambers have a convex face.
In one or more embodiments, the convex face is an outer face of the curved secondary air outlet chambers
In one or more embodiments, the plurality of secondary air outlet openings are located on a crest of the curved secondary air outlet chamber.
In one or more embodiments, the main body includes at least one secondary air inlet chamber.
In one or more embodiments, the secondary air inlet chamber is fluidly connected to at least one secondary air source.
In one or more embodiments, the at least one secondary air source is outside of the solid fuel combustion chamber.
In one or more embodiments, the secondary air inlet chamber is positioned on the back face of the main body section of the baffle plate.
In one or more embodiments, the curved secondary air outlet chambers are dome shaped.
In one or more embodiments, the curved secondary air outlet chambers are dimple shaped.
In one or more embodiments, the back face of the main body section has at least one opening thereon to allow fluid communication between the secondary air outlet chamber of the secondary air inlet chamber.
In one or more embodiments, a side face of the main body section has at least one opening thereon to allow fluid communication the secondary air inlet chamber between the secondary air outlet chamber of the secondary air inlet chamber.
In one or more embodiments of the invention there is a solid fuel combustion appliance having a baffle plate, the baffle plate having a main body section, the main body section having a front face and a back face, at least one curved secondary air outlet chambers having a plurality of secondary air outlet openings thereon and at least one secondary air inlet chamber fluidly connected to at least one curved secondary air outlet chamber to provide air to at least one curved secondary air outlet chamber.
The above and other aspects, features and advantages of the invention will be more apparent from the following more particular description thereof, presented in conjunction with the following drawings wherein:
The baffle plate (10) has a main body section (15) with a front face (17) and a rear face (20). A front section (25) is in an angled relationship with the main body section (15) and extends substantially along the width of the front end of the baffle plate (10). At the rear end (30) of the baffle plate (10) is a back section (35), both the front section (25) and back section (35) may be formed integrally from a single plate of material suitable for use in a combustion appliance having a combustion chamber or alternatively they may be joined to the main body section (15) by way of welding or other suitable technique.
The back plate (35) has a number of fixing points (40) to allow the back plate (35) to be secured to a combustion appliance in the appropriate manner known to those skilled in this field.
Positioned on the front face (17) of the main body section (15) are curved secondary air outlet chambers (42) and (44) with side panels (43a) and (43b), each of which has secondary air outlet openings (45a) positioned thereon. On the secondary air outlet chamber (42), the secondary air outlet openings (45a) are arranged in a straight line travelling substantially parallel with the longitudinal edges (47) and (48) of the secondary air outlet chamber (42).
The number of secondary air outlet openings thereon the curved secondary air outlet chambers may be variable depending upon specific requirements such as the overall size of the solid fuel combustion appliance and the size of the baffle plate (10).
On the front section (25) there is a plurality of secondary outlet openings (45c).
The baffle plate (10) further includes a secondary air inlet chamber (50) having a secondary air inlet opening (52) positioned on a rear end (54). An upwardly projecting flange (56) has an opening (58) to allow the option of further securing the baffle plate (10) to the solid fuel combustion chamber within which it resides.
The secondary air inlet chamber (50) is in fluid communication with a secondary air source that is external to the solid fuel combustion chamber so that at least the majority of the air entering into the secondary air inlet chamber (50) has a high level of oxygen compared to an interior of the solid fuel combustion chamber. The secondary air outlet chambers (42) and (44) are in direct communication with the secondary air inlet chamber (50) such that air entering into the inlet chamber (50) may then exit out through the openings (45a, 45b) on the outlet chambers (42) and (44) respectively.
In
In addition, the secondary air outlet openings (45) on the front section (25) may also be in fluid communication with the secondary air inlet chamber (50) to provide an additional input of air from the chamber (50) into the solid fuel combustion chamber. It is also considered within the scope of the present invention that the secondary air outlet holes may be connected to a separate secondary air inlet chamber if required, for example when additional airflow is required into the appliance.
The secondary air outlet chambers (42) and (44) are substantially convex in shape having a crest (46) located approximately equidistance from the parallel edges (47) and (48). The positioning of the row of secondary air outlet openings may be located closer to one edge than another, depending upon the final convex shape of the secondary air outlet chamber (42/44). The convex shape of the secondary air outlet chambers (42/44) may be substantially shaped like an aero foil or dome shaped or dimpled.
In use, the baffle plate (10) is positioned in the interior (100) of a solid fuel combustion appliance (110). The solid fuel (112) is ignited and creates a primary combustion zone (115). When the door (120) of the appliance (110) is closed outside air may enter by way of a top primary air control opening or inlet (125). The primary air entering via the top primary air control opening (125) is cooler than the air inside the combustion appliance and falls towards the bottom of the combustion chamber.
As the material (112) combusts, the resultant hot gases are lighter and travel upwards towards the baffle plate (10), which in turn is heated by the hot gases and the radiant heat from the primary combustion zone. The rising gases (140) travel upwards and over the secondary air outlet chambers (42/44) and as they pass over the secondary air openings (45) we have noted that this results in an increase of the velocity of the flow causing a decrease in pressure in the region adjacent to the secondary air openings (45) thus drawing in the secondary air from within the secondary air outlet chambers (42/44) through the openings (45). This is shown in
The shape and orientation of the secondary air outlet chambers (42) and (44) create a strong laminar airflow that until now has not been observed and the fresh secondary air (135) being brought in is then combusted which creates a secondary combustion zone (150). The laminar flow (130) along the front face (17) of the baffle plate (10) creates a substantial draw of secondary air and the newly created secondary combustion zone (150) provides an efficient means of combusting those as yet un-burnt gases/material from the primary combustion zone (115). In addition, flames may be visible in the secondary combustion zone (150) which add substantially to the visual effect overall from the combustion appliance.
The result of creating this efficient secondary combustion zone (150) is however that any un-burnt gases from the primary combustion zone are effectively and efficiently combusted in the secondary combustion zone (150) which therefore results in dramatic reduction of emissions from the combustion appliance compared to using a standard baffle system. The position and design of the secondary air outlet chambers that results in a laminar flow (130) over the front face (17) of the baffle plate (10) provides a strong draw of second air into the combustion chamber that until now has not been observed, at least not without the use of externally powered fans that force air into the appliance.
Although the invention has been herein shown and described in what is conceived to be the most practical and preferred embodiment, it is recognized that departures may be made within the scope of the invention, which is not to be limited to the details described herein but it is to be accorded the full scope of the appended claims so as to embrace any and all equivalent devices and apparatus.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2016900778 | Mar 2016 | AU | national |
