Fuel burner with air-deflecting object and method therefor

There is provided an improved fuel burner of the type having an air blower and blast tube. The improvement involves placement of an air-deflecting object inside the housing of the air blower or in the blast tube. In one embodiment, the object has a V-shaped cross section, and is attached to a gently tapered cylinder; the object can be held in place by inserting it through a hole of appropriate dimension in the air blower or blast tube, and tapping on the exposed end of the tapered cylinder until the latter is engaged in the hole. There is also provided a method of improving a fuel burner by mounting a air-deflecting object of the type described in the air blower housing or in the blast tube.

BACKGROUND OF THE INVENTION 
The present invention relates to heating devices of the type employing a 
blower to force air into a combustion chamber, where oxygen in the air 
reacts chemically with a fuel, such as oil or gas, to cause burning of the 
fuel. Oil burners used in space heating applications are conventionally of 
this type. In particular, the present invention relates to an improved 
design of fuel burner and a method and device for improving the 
performance of conventional designs of such a fuel burner. 
Fuel burners are used, for example, both in furnaces and in boilers. 
Convection, steam, and other methods are used to accomplish transfer of 
heat resulting from combustion sustained through operation of these 
devices. In practice, fuel burners are often designed to cause the air to 
enter the combustion chamber co-extensively with the fuel to be burned. 
When the fuel is oil, the oil is generally atomized or vaporized and 
thereafter caused to mix physically with the air and to flow into the 
combustion chamber with it. This air-fuel mixture then burns by reacting 
chemically in the combustion chamber. 
Various methods of improving the performance of fuel burners are known in 
the prior art. Some of these methods, pertinent to the invention described 
herein, operate by enhancing, in the furnace's combustion chamber, the 
extent of turbulence in the flow of the air-fuel mixture. Such additional 
turbulence has been created by the insertion into the combustion chamber 
of objects having surfaces specially shaped so as to tend to break up any 
smooth flow of the air-fuel mixture in the combustion chamber. Such 
additional turbulence has also been created in the prior art by employing 
an object to modify the flow of the air-fuel mixture at the point where it 
first enters the combustion chamber. 
In U.S. Pat. No. 3,918,885, issued for an invention of B. O. M. Palm et 
al., there is disclosed an apparatus and method for reducing the dynamic 
pressure of air that has been blown by the blower at the burner head of an 
oil-burning appliance. The invention utilizes a series of baffles to form 
a labyrinthine path for the air to flow between the output of the blower 
and the burner head. Certain other embodiments are disclosed that involve 
use of small turbines and slotted members, through which the air is 
required to pass. Generally, the labyrinthine structure is confined to the 
blast tube, and requires a plurality of baffles. Where baffles are not 
used, more complicated structures are employed. These structures are not 
readily conducive to modification of existing oil burners, and may depend 
on different physical principles for their successful operation. Nowhere 
does the patent refer to the use of a single protrusion for improving the 
performance of fuel burners, and nowhere does the patent disclose the use 
of an air-deflecting object in the blower housing itself. 
SUMMARY OF THE INVENTION 
It is a primary object of the present invention to provide an improved 
design of fuel burners and a method for improving the performance of 
conventional designs of fuel burners. 
It is a further object of this invention to provide increased fuel 
efficiency in fuel burners. 
Another object of this invention is to provide fuel burners utilizing a 
higher flame temperature and greater heat output, for a given rate of fuel 
consumption, than provided by conventional fuel burners. 
It is a further object of this invention to provide a device for insertion 
in a conventional fuel burner to improve the performance thereof. 
It is a further object of this invention to cause fuel to burn more 
completely than it would with conventional burners, and thereby also (i) 
to reduce the tendency of deposits to form in the combustion chambers of 
heating devices using fuel burners and (ii) to reduce the rate at which 
heat transfer in such heating devices is impeded by the formation of 
deposits. 
It is also an object of this invention to reduce the amount of 
environmental pollution caused by the operation of fuel burners in 
providing a specified amount of heat output. 
Furthermore, it is an object of the present invention to achieve the 
foregoing objects by modifying the nature of the air flow, compared with 
the air flow existing in a conventional fuel burner, beginning at a point 
prior to that at which the air enters the combustion chamber. 
In accordance with the invention, there is provided a fuel burner of the 
type having an air blower in a housing that is in communication with a 
blast tube. In this type of fuel burner, the air blower gives rise to an 
air flow in the blower housing and thereafter through the blast tube. The 
improvement in this fuel burner is provided by an object for deflecting a 
portion of the air flow and a means for mounting the object either in the 
blower housing or in the blast tube. 
In a preferred embodiment of the invention, the object has a generally 
V-shaped cross section, and is attached to a tapered cylinder. The object 
is mounted in a hole in the blower housing or in the blast tube; it is 
inserted through the hole so that the tapered cylinder engages against the 
perimeter of the hole. In another preferred embodiment of the invention, 
there is provided a device having an object with a V-shaped cross-section 
as aforementioned; also as aforementioned the object is attached to a 
tapered cylinder. The device can be used as previously described, and in 
accordance with a preferred embodiment of the method, to improve the 
performance of a fuel burner.

DESCRIPTION OF SPECIFIC EMBODIMENTS 
Referring now to the specific embodiments of the invention shown in the 
drawings by way of example only, FIG. 1 and FIG. 2 show two side views of 
a preferred embodiment of a device constructed in accordance with the 
present invention. In FIG. 2 the device is somewhat rotated about its 
longitudinal axis in comparison to FIG. 1. The device includes two 
prolongated spans 11 that lie in different planes. These spans have a 
common edge 21. The spans form the "object" end 15 of the device. In 
practice, the prolongated spans need not be wholly flat, and, furthermore, 
the non-common edges of the spans may be serrated. They are reinforced at 
this end of the device by strut 13, which is triangular shaped and runs 
between the spans. 
Still in reference to FIGS. 1 and 2, it can be seen that these spans are 
attached to a tapered cylinder 12. The cylinder is covered with recesses 
16, which occur in groups around the circumference of the cylinder. The 
right-hand end of the cylinder 14 is designated as the "head" of the 
device. 
In FIG. 3, which is an end view through plane 3--3 of FIG. 1, it can be 
seen that the prolongated spans 11 intersect to form a V-shaped 
cross-section. Also apparent is the strut 13 running between the spans. 
The spans intersect at the vertex 21 of the V-shape, which is also the 
common edge 21 of the spans shown in FIG. 2. The slight taper of the 
cylinder 12 makes it just visible in this figure. 
FIG. 4 is a view through plane 4--4 of FIG. 1. Thus the head 14 of FIG. 1 
is shown in direct view in FIG. 4. The head is fitted with an arrow 41. 
FIG. 5 is a cross-sectional view of the device shown in FIG. 2 taken 
through the plane of 5--5. This plane has been chosen to show the 
appearance of the device in cross-section at a point where there appears a 
group of four recesses 16. The recesses are formed so that there remains a 
plus-shaped structure 51 in this portion of the cylinder so as to insure 
its strength even in the presence of the recesses. 
FIG. 6 is a perspective view of the device of FIG. 1. Shown are the head 14 
and object end 15, the prolongated spans 11, their common edge 21, and 
reinforcing strut 13. Also shown are the tapered cylinder 12 and the 
recesses 16. 
In FIG. 7 is shown a portion of a fuel burner utilizing the invention. The 
invention is applicable to a fuel burner of the type having a blower, 
shown in part here as item 71, located in a housing 72, which is in 
communication with a blast tube 73. The blast tube interfaces with the 
wall 78 of a combustion chamber. In order to construct a fuel burner in 
accordance with the invention, and in order to improve a fuel burner in 
accordance with the invention, the object is placed in the air flow path 
of the fuel burner. In this preferred embodiment, a hole is formed in the 
wall of the lower housing 72, and there is inserted into the hole the 
device of FIGS. 1 through 6. The orientation of the device is important, 
although some beneficial effects have been observed regardless of its 
orientation. Preferably, however, the device is oriented so that air 
initially flows into the crotch of the V-shape formed by the intersection 
of the two prolongated spans. The air flow is indicated by arrows 76. To 
assist in determining the proper orientation of the device, it is provided 
with the arrow 75. In a preferred embodiment of the device this arrow 
points generally in the direction of the vertex of the intersection of the 
planes in which lie the prolongated spans. Thus the device is properly 
oriented when the arrow 75 points in the direction of the air flow, which 
can be determined by observation of the blower. Preferably, the device 74 
is placed at a point in the blower housing just prior to where the air 
leaves such housing and enters into the blast tube. In some instances, 
however, there is insufficient clearance between the outer portion of the 
blower 71 and the housing 72 to permit mounting of the device 74 in its 
preferred location. Under these circumstances, the device can be mounted 
in the blast tube. Such a location for the device is shown by the dashed 
outline of the device as item 77. 
FIG. 8 shows in further detail the operation of the device in a schematized 
cross-section. The blower 71 causes air, represented by arrows 76, to move 
through the lower housing and blast tube. Air in the vicinity of the 
device is deflected. Shown in cross-section are the prolongated spans 11, 
the reinforcing strut 13, and the tapered cylinder 12. It is believed that 
the presence of the prolongated spans causes a peculiarly efficacious 
turbulence to appear in the wake of the device. This turbulence is 
indicated by the curved arrows. In tests, installation of a device in 
accordance with the invention has been found to increase the temperature 
of the gases in the flu stack by approximately 130 degrees Farenheit in 
ordinary household furnaces, corresponding approximately to an increase of 
390 degrees Farenheit in combustion chamber temperature. Simultaneously 
there was determined to be a decrease in percentage of smoke, indicating 
that more complete combustion occurs when my invention is employed than 
when it is not. 
FIG. 9 shows a more complete view of the portion of the oil burner shown in 
FIG. 7. Location of the device 74 in FIG. 7 corresponds to the location of 
the device 94 in FIG. 9 in the blower housing 72. Similarly the 
alternative location shown for the device 77 in FIG. 7 corresponds to the 
alternative location for the device 97 shown in FIG. 9. Also shown in FIG. 
9 are the oil inlet pipe 91 and the nozzle 92 through which the oil 
emerges into the output of the blast tube. The oil-gas mixture emerges 
from the blast tube to the combustion chamber, a wall 78 of which is 
shown. On the emergence from the blast tube the ignited mixture forms a 
flame cone 93. Also shown are the blower, 71 and the blown air (as arrows) 
emerging from the blower. 
FIG. 10 shows another design of fuel burner. In this design of fuel burner 
a transformer 101 is placed at the top of the position where the blower 
housing is joined to the blast tube. Placement of the device in the 
usually preferred location cannot be effected with this particular design, 
since there is an undue risk that the device may run afoul of wiring to 
the transformer or that other complications may ensue. Moreover, the 
presence of the fuel line 91 also can interfere with placement of the 
device. Accordingly the device, shown as 102 in the figure, can be placed 
as shown. Also shown in the figure are combustion chamber wall 78, nozzle 
92, and blower housing 72, which items correspond to those described in 
reference to FIG. 9. 
Preferably, the device is able to withstand the relatively high 
temperatures present in the vicinity of the combustion chamber. Moreover, 
the device should be sufficiently rigid to withstand the pressures of air 
flow against the prolongated spans, also to withstand the tapping of the 
device into the hole that has been formed for it. These qualities may 
suggest that the device can be usefully constructed of a suitable metallic 
substance. While such substance may work, I have found that some 
resiliance in the material can be useful, inter alia, to assist in keeping 
the tapered cylinder thereof snuggly nested in the hole that has been 
drilled for it. Accordingly, I have found that choice of a suitable 
plastic such as polyphenylene sulfide, is an excellent material for this 
purpose, combining high melting point, durability, and some resiliance. 
Although the invention has been shown and described with particular 
reference to specific embodiments thereof in the interest of complete 
definiteness, it will be understood that it may be embodied in a variety 
of forms, diverse from those specifically shown and described, without 
departing from the spirit and scope of the invention as defined by the 
following claims.