US 3857671 A
A relatively inexpensive, effective orchard heater capable of being used without significantly causing atmospheric pollution can be constructed utilizing an elongated stack, the upper end of which is open and the bottom end of which is closed, with a cover provided with a centrally located opening. A carburetor plate is located so as to extend across the interior of the stack between the ends of the stack and is located so as to be spaced from the interior of the stack. First air holes are located in the stack between the carburetor plate and the upper end of the stack and second air holes are located in the stack away from its lower end beneath the carburetor plate. The openings and the holes are dimensioned with reference to the amount of fuel to be used in the heater so as to permit partial combustion of the fuel beneath the carburetor plate. Such partial combustion causes heating of the stack and of this plate which tends to vaporize the unburned fuel beneath the carburetor plate around it so as to draw in air through the air holes to a sufficient extent so that a flame is created above the upper end of the stack.
Description (OCR text may contain errors)
United States Patent [191 Sun City, Ariz. 853551  Filed: Feb. 8, 1973  Appl. No; 330,512
 US. Cl 431/352, 126/595, 431/347  Int. Cl. F23d 15/02  Field of Search 126/595; 431/351, 347, 431/350-353, 348
 References Cited UNlTED STATES PATENTS 2,220,603 11/1940 Hirtz et a1 431/350 2,518,689 8/1950 Hoger 431/342 3,364,968 1/1968 Mutchler 431/347 3,409,000 11/1968 Brader et a1. 126/595 3,626,924 12/ 1971 Sheppard 126/595 3,737,281 6/1973 Guth 431/352 Primary Examiner-Carroll B. Dority, Jr. Assistant Examiner-Larry 1. Schwartz Attorney, Agent, or Firm-Edward D. OBrian Cox Dec. 31, 1974 1 ORCHARD HEATER  ABSTRACT Inventor: Willis 13827 N 108th -i- A relatively inexpensive, effective orchard heater capable of being used without significantly causing atmospheric pollution can be constructed utilizing an elongated stack, the upper end of which is open and the bottom end of which is closed, with a cover provided with a centrally located opening. A carburetor plate is located so as to extend across the interior of the stack between the ends of the stack and is located so as to be spaced from the interior of the stack. First air holes are located in the stack between the carburetor plate and the upper end of the stack and second air holes are located in the stack away from its lower end beneath the carburetor plate. The openings and the holes are dimensioned with reference to the amount of fuel to be used in the heater so as to permit partial combustion of the fuel beneaththe carburetor plate. Such partial combustion causes heating of the stack and of this plate which tends to vaporize the unburned fuel beneath the carburetor plate around it so as to draw in air through the air holes to a sufficient extent so that a flame is created above the upper end of the stack.
4 Claims, 4 Drawing Figures ORCHARD HEATER BACKGROUND OF THE INVENTION The invention set forth in this specification pertains to orchard heaters. Such heaters are primarily utilized in preventing frost damage to various types of orchards in'the event of inclement weather. They are, however, utilized in other heating applications than in heating orchards.
In the past a great many different types of orchard heaters have been proposed and used. It is not considered that an understanding of the invention set forth in this specification requires a detailed analysis of any of these prior structures. It is considered that a need for improvement in the field of orchard structures is demonstrated by economic considerations and by the increasing demand for orchard heaters which can be used without causing significant atmospheric pollution.
The matter of the economics pertaining to the use of orchard heaters is somewhat complex. The initial cost of such heaters can frequently be very significant because many such heaters are used on large ranches or orchards. The lower the initial cost of an orchard heater the greater the economic desirability of such a heater to a user. This is not however the whole story. To be acceptable it is considered that an orchard heater must be capableof being used so as to accomplish orchard and similar heating with a comparatively minimum of fuel. This, of course, relates to the cost of operating an orchard heater.
The second factor of atmospheric pollution is becoming of increasing significance. At one time practically all agricultural heaters were referred to as smudge pots because of the atmospheric pollution resulting from the use of these heaters. As society becomes increasingly cognizant of the detrimental character of atmospheric pollution the use of prior heater structures tending to cause such pollution is being increasingly restricted. It is believed that in time the use of any orchard heaters which will cause or tend to cause any significant atmospheric pollution will be prohibited.
SUMMARY OF THE INVENTION An objective of the present invention is to provide new and improved orchard heaters. More specifically various objectives of the invention are to provide orchard heaters; which may be easily and conveniently be constructed at a comparatively nominal cost; which can be operated economically with little or no difficulty; which, when operated, are very effective for their intended purpose; and which when operated cause little or no significant atmospheric pollution.
In accordance with this invention these and various related objectives as will be apparent from a detailed consideration of the remainder of this specification are achieved by providing an orchard heater which includes: an elongated stack having an upper and a lower end. a cover provided with a centrally located opening located at the bottom of this stack, leg means for supporting this stack. vertically, a support located beneath the opening in the cover, a fuel nozzle located on the support so as to be capable of directing unburned fuel through the opening of the cover without such fuel contacting or impinging upon the cover, a carburetor plate located across the interior of the stack between the ends of the stack so as to be spaced from the interior of the stack, first air holes located in the stack between the carburetor plate and the upper end of the stack and second air holes located in the stack away from the lower end of the stack and beneath the carburetor plate.
An orchard heater in accordance with this invention is constructed so that the opening noted and the second air holes are proportioned with reference to the fuel to be used with the orchard heater so that as the heater is operated there will be partial combustion of this fuel in the stack beneath the carburetor plate. Such partial combustion will serve to heat the stack and then carburetor plate so that both will tend to radiate the heat resulting from such partial combustion. Heat from the carburetor plate and the stack will be radiated to the unburned fuel beneath the carburetor plate as the heater is operated so as to tend to cause vaporization of this fuel so that it may be more efficiently burned. Fuel heated in this manner and the other gasses beneath the carburetor plate in the stack will pass around the carburetor plate in a wall-like flow pattern past the first air holes so as to be mixed with air drawn in through these air holes in such a manner that a flame will be created above the upper end of the stack.
BRIEF DESCRIPTION OF THE DRAWING Further details of the present invention are best explained with reference to the accompanying drawing in which: I
FIG. l is a side-elevational view of a presently preferred embodiment or form of a orchard heater in accordance with this invention;
FIG. 2 is a cross-sectional view taken at line 2-2 of FIG. 1;
FIG. 3 is a partial cross-sectional view taken at line 3--3 of FIG. 2, and
FIG. 4 is an enlarged, fragmentary cross-sectional view corresponding to part of FIG. 2.
It is to be realized that the orchard heater illustrated in the drawing is a specific structure utilizing the essentially intangible concepts of the present invention verbally set forth in the appended claims. Those skilled in the art of agricultural or orchard heaters will be able to utilize these concepts in various somewhat differently appearing and differently constructed heaters through the use or exercise of routine skill in the field of this type of heater.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT In the drawing there is shown an orchard heater 10 in accordance with the present invention which includes an elongated, hollow, metal stack 12 having an upper end 14 and a lower end 16. Preferably this stack 12 is of a conical shape as shown in the drawing since a conical shape as illustrated apparently is advantageous in achieving effective operation of this heater 10. It will be apparent that the upper end 14 is of larger diameter than the lower end 16 and that this upper end 14 is not covered. The lower end 16 is, however, covered by a flanged cover 18 having'with a centrally located circular air and fuel opening 20.
A series of bolts 22 extends through the cover 18 so as to secure angled legs 24 to this cover 18. Preferably I both the cover 18 and the legs 24 include matching dimples 26 so that only a single bolt 22 is required to secure each leg 24 in place. A support bracket 28 is secured by one of the bolts 22 to one of the legs 24 so that an end 30 of this bracket 28 is located so as to be spaced from the hole 20 beneath and parallel to the cover 18. The bracket 28 preferably also includes dimples 26 as previously indicated so that it may be se-' curely held in place against movement by a single one of the bolts 22.
This end 30 is provided with a centrally located aperture 32 which is'aligned with the axis of the stack 12. A conventionalfuel nozzle 34 designed to spray a coneshaped spray of finely divided liquid fuel is mounted in the aperture 32 in any convenient conventional manner. Preferably the nozzle 34 is mounted by being press fitted within the aperture 32. During the use of the heater this nozzle 34 is connected to a fuel source or supply in a conventional manner through a hose 36.
The location of the nozzle 34 with respect to the hole is considered quite important to the present invention. This nozzle 34 should be located with respect to the hole 20 so that the cone of sprayed fuel emitted from itwill pass into the interior of the stack 12 without contacting or impinging upon the cover 18 at the pe riphery of the hole 20. if such fuel should hit against the cover -18 there will be a fuel loss andthere is danger of a degree of atmospheric pollution.
On the other hand, the nozzle 34 should be locate so that the spray of fuel from it comes as close to the edge of the hole 20 as reasonably possible without there being danger of any of the fuel hitting against the cover 18. When the nozzle 34 is located in this manner the spray of fuel from the nozzle 34 will be spaced from the periphery of the hole 20 a short distance so that what may be regarded as primary'air will be drawn in to the interior of the stack 12 as fuel is sprayed into this stack 12 so as to create a combustible mixture within the bottom of this stack 12.
Such a combustible fuel-air mixture may be ignited in a variety of ways. Thus it can be ignited through the use of a hand-held flame. It is preferred to ignite such a mixture in the heater 10 as initial fuel is supplied to this heater 10 through the use of a conventional electrically operated ignitor 38 mounted in a conventional manner on the upper surface of the cover 18 adjacent to and spaced from the hole 20. Such an ignitor 38 is heated electrically to a temperature which is adequate in order to cause initial combustion of a fuel-air mixture within the heater 10 as the operation of this heater 10 is started. After the initial combustion takes place, the heat of the combustion will normally be adequate to sustain further combustion within the heater 10.
An important facet of the present invention is the manner in which such combustion is sustained and regulated as the heater 10 is operated. By virtue of the fact that the dimensions of the hole 20 around a spray of fuel from the nozzle 34 are limited, the primary air emitted through this hole 20 will not be adequate to sustain complete combustion of a significant proportion of the fuel used. In the heater 10 what may be referred to as second air holes 40 are located equidistant from one another in planes transverse to the axis of the stack 12 above or away from the cover 18 and below a circular, imperforated carburetor plate 42 positioned transverse to the axis of the stack 12.
This plate 42 preferably is held in place by extending legs or flanges'44on its fitting within a peripheral groove 46 in the stack 12 so that it is located with its outer edge 48 uniformly spaced from the interior of the stack 12. The plate 42 can, however, be mounted in other equivalent manners. The location of the plate 42 between the upper and lower'ends 14 and 16 of the stack 12 is preferably chosen with reference to the number of second air holes 40 and to the dimensions of the hole 20 and to the fuel to be used so that as the heater 10 is operated only partial combustion will occur beneath this plate 42.
It is considered the effective results require the combustion of from about 30 to about 50 percent by weight of the fuel used within the space of the carburetor plate 42 and the cover 18. Preferably the amount of fuel burned within this space is about 40 percent by weight of the total fuel used. Since the combustion which takes place within this space is not an instantaneous thing the plate 42 should be located far enough .up in the stack 12 so as to achieve an amount of combustion as indicated. It is considered that this requirement dictates that the plates should be at least halfway up the height of the stack 12 and that preferable results are achieved when this plate 42 is approximately two-thirds of the way up the length of the stack 12 as shown. The plate 42 should not, however, extend further than about three-fourths the way of the stack 12 for the heater 10 to function effectively.
The second air holes 40 are preferably located so that the lowest of these holes are at least 40% of the distance up the stack 12 from the cover 18 to the plate 42. Preferably these holes 40 are spaced substantially as shown. When the holes 40 are located as indicated there is substantially no danger of flame being emitted from them during the combustion within the space from the cover 18 to the plate 42 as the heater 10 is operated. Further, as this heater 10 is operated what may be referred to as secondary air is drawn into the stack 12 through the holes 40 and mixed by the movement of gas in the stack 12 so as to support the combustion occurring beneath the plate 42.
Such combustion produces a significant amount of heat and serves to heat up both the lower part of the stack 12 and the carburetor plate 42. The heat taken up by the stack 12 will be radiated externally of this stack to a significant degree. Some of this heat taken up by the plate 42 will be radiated back into the interior of the stack 12 in the space beneath the plate 42 so as to tend to heat the fuel and the gasses within this space beyond a temperature necessary to support combustion. As a consequence of this, the unburned fuel within the space beneath the plate 42 will tend to become heated prior to its combustion so as to be thoroughly vaporized and will thus be placed in a form more specifically a vapor form-in which it can be 7 readily burned.
As the partial combustion occurs beneath the plate 42 in the stack 12 there will be a degree of turbulance in the mixture of fuel, air and products of combustion beneath this plate 42 which will tend to further place the unconsumed fuel in a form in which it can effectively be burned-The mixture indicated will escape from beneath this plate 42 around its outer edge 48 so as to tend to flow upwardly in the shape of a wall-like nearly cylindrical, slightly conical flow path. As this mixture flows in this direction it will flow past what may be referred to as first air holes 50 which are located equidistant from one another in planes traverse to the axis of the heater 10 above this plate 42.
The flow in this manner will draw into the moving mass of material what may be referred to as tertiary air.
come mixed with this tertiary air. The size and spacing of the holes 50 is preferably determined so that the amount of such tertiary air will be adequate so that substantially all fuel used is consumed by combustion taking place above the plate 42. The principal part of such combustion will take place in a large flame extending outwardly from the upper end 14. Ambient air around this flame will, of course, enter into the combustion which takes place in this flame. This flame will also radiate heat to the surrounding area and also will serve to heat the ambient air.
It is not to be assumed from this statement that heat is only radiated by the flame created. In the heater the entire stack 12 serves toradiate heat in a surrounding area. It is considered that the conical shape of this stack 12 is materially beneficial in that this conical shape enables the heater 10 to more effectively radiate heat than if the stack 12 was of a cylindrical configuration. It is considered also that the conical shape effectively accommodates the increase in gas volume cre ated by the formation of cumbustion products as the heater 10 is operated. This operation effectively involves the formation of a first wet flame beneath the carburetor plate 42 and the formation of a second flame above this carburetor plate in which there is efficient combustion.
As the result of the action achieved, heaters constructed as indicated in the preceding discussion have been and are being utilized in the heating orchards. it is considered significant that laboratory tests using these heaters with diesel fuel have revealed the presence in the gasses given off from them of no unburned hydrocarbon. lt is believed, however, that in spite of their efficiency that the gasses given off by these heaters must contain at least some trace quantities of hydrocarbons. It is considered that this is an indication that these heaters can be effectively and economically operated without significant atmospheric pollution. I claim:
1. An orchard heater which includes:
an elongated stack having the shape of a frustrum of a cone, said stack having an uncovered upper end and a lower end, said upper end being of longer diameter than said lower end, a cover having a centrally located opening covering the lower end of said stack,
leg means for supporting said stack vertically a support located beneath said opening in said cover,
a fuel nozzle located on said support so as to be capable of directing a spray of unburned fuel through said opening without such fuel contacting said cover,
the size of said opening being sufficiently small so that the air entering said stack through said opening during the operation of said heater is insufficient to sustain complete combustion of the fuel emitted from said nozzle,
an imperforate carburetor plate located across the interior of said stack between said ends of said stack, said carburetor plate having an outer edge uniformly spaced from the interior of said stack,
first air holes located in said stack between said carburetor plate and said upper end of said stack,
a plurality of second air holes located in said stack beneath said carburetor plate, said second air holes being spaced from said cover,
said carburetor plate being the only obstruction lo-' cated within theinterior of said stack and being located between said ends of said stack so that partial combustion of fuel supplied through said nozzle will occur beneath said carburetor plate causing said stack and said carburetor plate to be heated, such heating resulting in the heating of fuel and air within said stack beneath said carburetor plate,
said carburetor plate serving to distribute a mixture of air, unburned fuel and combustion products so that said mixture flows around the periphery of said carburetor plate and then upwardly and outwardly from said upper end of said stack past said first air holes so as to burn in a flame extending from said upper end of said stack, and
the air necessary to support combustion of the fuel burned in said heater entering said heater through said opening and said first and said second air holes.
2. An orchard heater as claimed in claim 1 wherein:
said carburetor plate and said second air holes are located and the dimensions of said second air holes and said opening are determined with reference to the fuel to be supplied to said heater so that from about 30 to about 50% of the fuel supplied to said heater will be consumed in the space between said cover and said carburetor.
3. An orchard heater as claimed in claim 1 wherein:
said carburetor'plate is located from about one-half to about three-fourths of the distance from said cover to said upper end.
4. An orchard heater as claimed in claim 1 wherein:
said carburetor plate and said second air holes are located and the dimensions of said second air holes and said opening are determined with reference to the fuel to be supplied to said heater so that from about 30 to about 50 percent of the fuel supplied to said heater will be consumed in the space between said cover and said carburetor, and
said carburetor plate is located from about one-half to about three-fourths of the distance from said cover to said upper end.