US2186156A - Combustion apparatus - Google Patents

Description

Jan. 9, 1940.- 5, gra 2,186,156

COMBUSTION APPARATUS.

Filed April 14, 1939 3 Sheets-Sheet l I N VE NTOR. 557V l ALJEAN @MZMZJM ATTORNEY.

1940- B. VALJEAN COMBUSTIQN APPARATUS Filed April 14, 1939 :5 Shets-Sheei', 2

-' INVENTOR.

557V V4LJF/4/V Fwd/41,4

ATTORNEY.

Jan. 9, 1940. B. VALJEAN I v 2,186,156

COMBUSTION APPARATUS Filed April 14, 1939 5 Sheets-Sheet I5 I r v V Q V I I 7 I H H I Q Q o o 4 %o o o- INVENTQR 55 N 144/. JEAN ATTORNEY.

Patented Jan. 9, 1940 PATENT OFFICE COMBUSTION APPARATUS Ben Valjean, Lansing, Mich, assignor to Motor Wheel Corporation, Lansing, Mich, a corporation of Michigan Application April 14, 1539, Serial No. 267,811 15 Claims. (01. 158-91) This invention relates to vaporizing pot type burners of the type illustrated in my prior Patent No. 2,073,270, and the present invention is an improvement upon the invention disclosed in my said prior patent.

The present application is a continuation in part of and substitute for my co-pending applications Serial No. 127,601 filed February 25, 1937 for Combustion apparatus, and Serial No. 231,670

filed September 26, 1938 for Combustion apparatus.

structurally, the present improvement consists in providing an inclined or biased baffle in place of the horizontal baflle disclosed in my prior 1 Patent No. 2,073,270. The advantage obtained by the present improvement over the advantages of my prior patent is a clean and stable fire throughout both the low and intermediate operating stages as compared with the clean fire obtained by my prior patented structure either at the lowermost or at the intermediate operating stage, but not at both.

The present invention will best be understood in connection with a review of the entire develop- 35 ment of which it forms a part. My original invention resides in the discovery that one of the reasons why a clean fire could not be obtained in the lower operating stages of pot type burners was because the premixing action of the burner 30 at those stages was adversely affected by eddy currents. This difliculty was overcome without adversely affecting the operation of the burner by the use of a baflie positioned as disclosed in my prior patent.

.85 However, it was found that a single horizontal baffle was not sufficient to obtain a clean fire at both the low and the intermediate operating stages. Following that discovery, I proposed to use two bafiles instead of one, located in such a 40 position as to eliminate eddy currents at both the intermediate and the lower operating stages. This development is disclosed in my copending application Serial No. 70,300. However, upon using two baflles I found that the capacity of the 4!!- burner was somewhat reduced, which I believe was because the two bafiles interfered with the reflection of heat at the higher operating stages to such an extent as to interfere with the vaporization of liquid fuel, and thereby reduce the 50 capacity of the burner. Thus, a clean fire throughout both the lower and intermediate stages could not be obtained through the use of two horizontal bafiles without some sacrifice of the overall capacity of the burner. While this ob- 55 jection is not so great as to completely destroy the benefit of the use of two bailles, the advantages of the two bailles are somewhat offset by reason of this fact.

The present invention is the result of my efforts to attain the benefits of the use of two baflles, namely, a clean fire throughout both the lower and intermediate operating stages, without thedisadvantages of the use of two baflles, namely, a reduction in the capacity of the burner. This is accomplished in accordance with the 10 present invention by the use of an inclined or biased baflle having its lower edge in the position which would be occupied by the lower of two baflles, and its upper edge in the position which would be occupied by the upper 01' two battles, in a burner utilizing two baflles. I have discovered that such a biased baflie accomplishes almost as I advantageous results as the use of two horizontal baflles, while maintaining the samecapacity of the burner as is obtained when a single bailie is 0 used.

It is important, however, to avoid any direct impingement of air against the biased baflle, otherwise much of the advantages of the use of a baflie will be destroyed by the maintenance of combustion at the point of such impingement, even at the high fire stage of operation. This is likely to cause smoke and the deposit of carbon in the region of the impingement. V

In the drawings: 9

Figure 1 is a sectional view of a combustion device of the space heating type including a burner embodying the present invention;

Figure 2 is an enlarged sectional view of the burner shown in Figure 1;

Figure 3 is a top view of the burner, partly in section, taken on the line 33'of Figure 2;

Figure 4 is an elevational view of a blank forming one-half of the burner wall;

Figure 5 is an elevational view of a blank form ing the other half of the burner wall;

Figure 6 is an enlarged sectional view of substantially the same burner as shown in the preceding figures, equipped with a slightly modified form of baflle; and

Figure 7 is a top view of the burner shown in Figure 6, partly in section, taken on the line 1--'| of Figure 6.

The space heater illustrated in Figure 1 includes an outer casing l0, forming an upper combustion chamber II and a lower air chamber l2.

A burner 13 is located in the air chamber l2. The combustion chamber II is provided with a door 14, a top l5, and a flue outlet It. The flue outlet I6 is connected to a chimney II by a pipe l8. Pipe I8 is provided with a conventional form of draft regulator shown at II.

The burner IS, the details of which will be described presently, is mounted in the casing ID by means of what may be termed a jack screw 20. Screw 20 is threadedly mounted in the intersecting portions of the detachable legs 2|, of which there are preferably}. Legs 2| are secured to an intumed flange 22 at the bottom of the casing In by means of bolts 23. The legs 2| do not close the bottom of air chamber l2 so that this chamber is open to the atmosphere. Casing I 0 and burner II are formed with cooperating shoulders lfla and I 3a respectively. Burner shoulder l3a is held against the casing shoulder Illa by suitable adjustment of the screw 20. A seal, preferably asbestos, is positioned between the shoulders Illa and Na to prevent the passage of air between the burner and the casing at this point.

Oil is supplied to burner I: from a source not shown through the 011 line 24 with which is associated a manually operable regulating valve, i1- lustrated diagrammatically at 24a. Any conventional form of automatic valve may be substituted for the manually operated valve 24a.

Burner l3 includes a thin sheet metal side section 25, a heavier metal bottom wall 26 permanently secured to the lower edge of the side section, and a heavy metal top wall 21 removably secured within the upper edge of the side section. A sectional anti-explosion ring 22 is shown mounted upon top wall 21.

The anti-explosion ring 28 is so named because it prevents complete extinguishment of the fire in the combustion chamber II, and as a result explosions are prevented. The anti-explosion ring 28 is arranged with respect to the openings 35 whereby at least some of the air entering therethrough impinges against the ring; and to efiectively prevent contact therewith of any great quantity of fuel vapors. Thus, there is always maintained adjacent the inner periphery of the anti-explosion ring a mixture of air and fuel vapors containing a sumcient quantity of air to support combustion. So long as fire is maintained in the apparatus the possibility of an explosion because of the generation of an excess of fuel vapors is effectively eliminated.

Top wall 21 and the anti-explosion ring 28 are preferably formed of cast metal. Top wall 21 is provided with a large central opening 21a. The

anti-explosion ring 28 is also formed with a central opening 28a, somewhat larger than opening 21a.

The sheet metal side section 25 is of generally cylindrical form, being here shown as of substantially uniformly increasing diameter from its lower edge to its upper edge. So far as the present invention is concerned, the side section may be either tapered as shown, a true cylinder, or of oval cross section. Accordingly, the words generally cylindrical are here used in the broader sense as including all of these varying forms.

Adjacent the upper extremity the side section 25 is provided with a radially inwardly extending rib 29 and the outwardly extending rib or shoulder 130.. Top wall 21 is mounted upon the radially inwardly extending rib 29. The sectional anti-explosion ring 28 is in turn mounted upon the top wall 21. The anti-explosion ring 28 includes the depending legs or vanes 30 which space the anti-explosion ring from thetop wall 21. At its upper edge the side section 25 is indented radiallyinwardly, as indicated at II, to lock the anti-explosion ring in place.

The bottom wall 25 is of pan-like formation, in cluding the cylindrical side portion 28a, which togetherwith side section 25 forms the side wall of the burner. 'The bottom is secured to the side section 25 by telescoping the cylindrical side 25 within the upper edge of the bottom section 26a. It is secured in this position by any suitable securing method, as by welding.

The bottom wall is provided with a fuel reservoir in the form of a sump 32 adjacent one side thereof. This sump is of limited circumferential and radial extent and constitutes a vaporizing zone. It is desirable but not essential as the oil will normally extend over only a limited area of the bottom wall before it is vaporized. This limited area is embraced within the term "vaporizing zone. An oil inlet opening 33 is formed in the side 26a. of bottom wall 26 immediately over the sum 32. Oil inlet opening 33 is suitably threaded to receive the threaded extremity of oil supply pipe '24.

The side section 25 is provided with a series of what may be termed primary air inlet openings 34 between its lower edge and the radially inwardly extending rib 29. These openings are of substantially but not exactly uniform size and are spaced substantially uniformly about a major portion of the side section 25. As shown, there are six vertically spaced horizontal rows. The lower row includes 26 openings of approximately .1 inch diameter. The second, third, fourth and fifth rows, counting from the bottom, would each designated by xs in the drawings, no openings have been provided. These openings have been omitted for a reason which will be explained presently. The top or sixth row of primary air inlet openings includes 26 openings of approximately .09 inch diameter. The diameter of the lower edge, of th side wall is approximately 10% inches. The diameter at the top of the burner is approximately 11 inches, and the overall height of the side section 25 is approximately 7% inches.

The side section 25 of the burner is composed of two halves, shown prior to bending, in Figures 4 and 5. The two blanks are perforated as shown by the small circles on each blank. The as indicate the spots where the openings would be if they were equally spaced in each row, but have been omitted as stated above. The two halves are bent into substantially semi-circular form and the ends joined by welding. The end C-D of the blank shown in Figure 4 is joined to the end C'D' of the blank shown in Figure 5. The ends AB and A'-B' are also joined together.

From the foregoing dimensions it will be seen that the openings 34 are not of exactly uniform size and spacing, although approximately so. These openings are referred to as being of uniform size and spacing for want of a better means of describing the size and spacing thereof. The only requisite in connection with the size and spacing of these openings is that they be of such character as to permit localization of the zone of combustion at various heights, within the burner, depending upon the volume of oil admitted to the burner. This requirement will be describ in further detail in comiection with the operation of the burner.

A series of additional air inlet openings 35 which may be referred to as secondary air inlet openings, are formed in the radially outwardly extending rib 13a. There are 52 of these openings arranged in a horizontal row, and they are of approximately .11 inch in diameter. The openings 35 are adapted to admit air into the burner between the top wall 21 and the anti-explosion ring 28, and to direct the same toward .the anti-explosion ring.

A generally disk-like partition or baflie 36 is positioned within t e burner 13 in an inclined position. The lower edge of the partition is located above the lowermost row of openings 34 and above the oil inlet opening 33. The upper edge of the partition 36 is located in the vicinity of the uppermost openings 34, preferably just under the next to the highest row of openings. As here shown the partition is arranged so that approximately one-third of the air inlet openings 34 are below the partition and two-thirds of these'openings are above. This division of the openings 34 is considered desirable to obtain the best characteristics at both low and intermediate fire, but may be varied within reasonable limits without destroying the advantage of the present invention.

As previously mentioned, the uniformity of spacing of openings 34 has been destroyed by the omissionof openings at the points marked X. These points are those which, if provided with openings 34, the air entering therethrough would impinge directly against the baflle. It is important that this should not occur in order to avoid production of a luminous flame at points of impingement with resulting formation and deposit of carbon particles.

' The partition 36 is provided at its lower end with an integral projection 36b, and the side section 25 has a recess 25a formed therein directly above the fuel inlet opening 33 into which the projection 36b is inserted. At'the upper end of the partition 36 is a foot 360 which extends upwardly from the upper edge of the partition 36 to the under side of the top wall 21. In this manner the partition is firmly held within the burner so that even if the burner is inverted the partition 36 cannot be displaced. The partition is also provided with a single relatively large opening 36a at its center. The opening is preferably somewhat smaller than the openings 21a in top wall 21. It is also preferably arranged in substantial but not necessarily exact alignment with opening 21a in top wall 21.

.In Figures 6 and '1 there is shown a burner 31 of the same general construction and proportions as the burner 13 with the exceptions hereinafter noted. The bottom wall 38 of burner 31 has a cylindrical side portion 38a which is disposed inside of the perforated side section 39. Side wall section 39 is provided with primary air inlet openings 40 arranged substantially the same as openings 34 in burner l3. 3

A generally disk-like partition 4| is positioned within the burner 31 in an inclined position. The lower edge of the partition is located below the lowermost row of openings 40 and above the oil inlet opening 42. The upper edge of the partition 4| is located in the vicinity of the'uppermost openings 40, preferably just under the next to the highest row of openings. The partition is arranged so that approximately one-third of the air inlet openings 40 are below the partition and l arouse two-thirds of these openings are above. This division of the openings 40 is considered desirable for best "results.

The partition is provided with cooperating notches or recesses adjacent its lower edge adapted to engage the upper edge of the side portion 38a of the bottom 38 to locate the partition within the burner. The partition is also provided with a single relatively large opening 41a which is spaced from the edge of the partition but is located nearer the lower edge than the upper edge. This opening is preferably somewhat smaller than the opening 42a in top wall 42. It is also preferably arranged in substantial but not necessarily exact alignment with opening 42a in top wall 42.

The present invention resides in the combination with the burner of the bias partition. In order to appreciate the function ofthe partition within the burner, it is necessary to describe the includesall burners which operate on the principle of vaporizing oil in a pot, premixing air with the oil vapors thus formed, and burning the premixture of oil and air vapor in a region remote from the surface of the liquid oil. Such burners are exemplified by the present inventors prior Patents Nos. 1,512,869 and 2,073,270.

In the burner of Figures 1 to 5, oil is delivered to the sump 32 from the oil inlet opening 33 and is initially ignited at that point by any suitable form of ignition, either automatic, or by actually introducing a lighted taper. As soon as the oil has been ignited, the heat'from the resulting flame begins to vaporize the liquid oil. The vapors thus formed cannot, of course, be burned without admixing air therewith. So long as but.

a limited quantity of oil vapors are generated, combusiton takes place below the partition 36, the necessary air being supplied from the openings 34 which are located below the partition 36. However, when the rate of vaporization of oil has reached a I point where the volume of vapors generated exceeds that which forms a visibly combustible mixture with the air available from the air inlet openings 34 below the partition 36, visible combustion then occurs exclusively above the partition 36. When that does occur, then all of the air introduced through the air inlet openings below the partitions 36 is being utilized for premixing with the oil vapors before combustion occurs.

,After combustion has been localized above the partition 36, a further increase in the rate of vaporization of the oil (increasing the flow of oil) will cause the zone of combustion to move up in the burner above the top wall 21. The number and size of the secondary air inlet openings 35 and their arrangement with respect to the antiexplosion ring 26 are such that the lower limit of the zone of combustion will never pass above the anti-explosion ring 28. I

During the lower and intermediate stages of operation, i. e., when combustion is located wholly or partially below the partition 36, that partition effectively excludes eddy currents from the lower portion of the burner, thus producing a stable operation of the burner at both the lower and intermediate operating stages. In the higher operating stages, i. e., when combustion is located above partition 36 and partially or Wholly below top wall 21, the top wall effectively excludes eddy currents from the upper portion of the burner. thus producing a stable operation of the burner in its higher operating stages.

In this manner, opportunity is afforded for the natural premixing of air with the oil vapors without interference from eddy currents or the like, before the vapors are burned during substantially all of the operating stages of the burner. By operating stages, it is intended to exclude the lighting stage or the pilot stage when the burner operates automatically, at which stages the initial combustion occurs immediately over the surface of the oil. The ignition stage is of very short duration.

It will, of course, be understood that combustion may be localized at various heights within the burner l3 by regulating the volume of oil admitted to the burner. This is an inherent and distinctive characteristic of all vaporizing pot type burners. Thus, as previously mentioned, when combustion is localized in the upper part of the burner, the air inlet openings 34 in the lower part of the burner serve to introduce air for premixing in advance of combustion.

The operation of burner 31 is substantially the same as the operation of burner I 3 just described. The only difference is that burner 31 will produce a slightly lower clean fire than will burner I 3. However, this advantage of burner 31 is somewhat offset by the fact that there is a tendency under certain adverse draft conditions for the lowest fire in burner 31 to be accidentally extinguished. The low fire in burner I3 is not subject to such extinguishment. Except for the differences just mentioned, burners l3 and 31 operate in the same manner.

The term primary air inlet openings as used in the claims refers to those openings which at.

certain stages of operation of the burner introduce air for pro-mixing and at other stages of operation introduce air directly to the zone of combustion. These openings are exemplified by the openings 34 of this application.

The term secondary air inlet openings as used in the claims refers to those openings which serve only to introduce air above or directly into the zone of combustion and do not introduce air for pre-mixing with oil vapors in advance of combustion. These openings are exemplified by the openings 35 of this application.

The scope of the invention is indicated in the appended claims.

I claim:

1. Combustion apparatus of the vaporizing pot type comprising a burner provided with a plurality of spaced apart primary air inlet openings, a bottom wall for the burner, fuel supply means for delivering a quantity of liquid fuel to a section of the burner bottom wall constituting a vaporizing zone, said vaporizing zone being located below and adjacent certain of said primary air inlet openings, and bailie means positioned within the burner in an inclined position with the lower edge thereof disposed adjacent the bottom of the burner in vertical alignment with the vaporizing zone, the upper edge of the bailie means being substantially removed from the bottom of the burner, said baille means being constructed and arranged to provide for restricted communication between the lower and upper portions of the burner.

2. Combustion apparatus of the vaporizing pot type comprising a burner having a side wall provided with a plurality of spaced apart primary air inlet openings, fuel supply means for delivering a regulatable quantity of liquid fuel to the burner, said fuel supply means including a. fuel inlet opening formed in a wall of the burner below the lowermost primary air inlet openings, and a partition disposed within the burner in an inclined position, the lower edge of the partition being positioned between the fuel inlet opening and the adjacent lowermost primary air inlet openings, said partition being constructed and arranged to provide for restricted communication between the lower and upper portions of the burner.

3. Combustion apparatus of the vaporizing pot type comprising a burner having a side wall provided with a plurality of spaced apart primary air inlet openings, the burner including a bottom wall formed to provide a vaporizing zone of limited area adjacent one side of the burner, fuel supply means for delivering a regulatable quantity of fuel to the vaporizing zone, and an inclined partition disposed within the burner with a plurality of said primary air inlet openings therebelow and a majority of said primary air inlet openings thereabove, the lower edge of the partition being disposedadjacent the bottom of the burner and immediately above the vaporizing zone, the upper edge of the partition being substantially removed from the bottom of the burner, the partition being constructed and arranged to provide for restricted communication between the lower and upper portions of the burner.

4. Combustion apparatus of the vaporizing pot type comprising a burner having a top wall with an outlet opening therein and a side wall provided with a plurality of vertically spaced horizontal rows of primary air inlet openings, means associated with said burner for causing air to fiow through said primary air inlet openings into the burner and out of the'top thereof, fuel supply means for delivering a regulatable quantity of liquid fuel to the bottom of the burner, and a centrally apertured partition disposed within the burner with a portion thereof located below the lowermost primary air inlet openings, said partition being constructed and arranged with respect to the primary air inlet openings so that the air admitted through at least some of the lowermost primary air inlet openings passes beneath the body of said partition and upwardly through the central aperture therein.

5. A mechanism for burning liquid fuel which includes a chamber and means for admitting a liquid fuel to the bottom thereof, a wall for said chamber provided with a plurality of primary'air apertures positioned at a plurality of heights above the level of the liquid fuel, said chamber being further provided adjacent its upper edge with secondary air inlet means, and an apertured bafile positioned in said chamber and including a portion located at a level below the lowest of said primary air apertures and a portion extend ing to a level above the lowest of said primary air apertures, whereby a portion of the lowest primary air apertures are located above said baflle and a portion below.

6. Combustion apparatus comprising a burner of the vaporizing pot type having a bottom wall and a side wall, the side wall being provided with a plurality of primary air inlet apertures at various levels, fuel supply means for delivering. liquid fuel to the burner in regulatable quantities, and bafile means arranged within the burner in an inclined position with its upper edge located near the uppermost primary air inlet apertures and its lower edge located near the lowermost pri mary air inlet apertures, said bame means being formed toprovide for restricted communication between the upper and lower parts of the burner p t.

7. Combustion apparatus as defined in claim 6, wherein the primary air inlet apertures and the baflie means are so constructed and arranged as to substantially avoid any direct impingement of the primary air against the baflie means.

8. Combustion apparatus as defined in claim 6, wherein the means for delivering liquid fuel to the burner includes a fuel inlet opening formed in a wall of the burner near the junction of the side wall and the bottom wall, and wherein the battle means is arranged with its lower edge above and adjacent said fuel inlet opening.

9. Combustion apparatus as defined in claim 6, wherein the baflie means consists of a centrally apertured disk having its periphery arranged in close proximity to the side wall of the burner pot.

10. Combustion apparatus as defined in claim 6, wherein the bailie means in its entirety is arranged with at least some of the air inlet openings located above it and at least some of the air inlet openings located below it.

11. Combustion apparatus comprising a burner of the vaporizing pot type having a bottom I wall and a side wall, the side wall being provided with a plurality of primary air inlet apertures arranged in vertically spaced horizontal rows, fuel supply means for delivering liquid fuel to the burner in regulatable quantities, and baflie means arranged within the burner with its median plane intersecting a plurality of the rows of primary air inlet apertures, said baflie means being formed to provide for restricted communication between the lower and upper parts of the burner pot.

12. Combustion apparatus as defined in claim 11, wherein the bafile means and the primary air inlet apertures are so constructed and arranged as to substantially avoid any direct impingement of the primary air against the baffle means.

13. Combustion apparatus as defined in claim 11, wherein the baiile means consists of a centrally apertured disk having its periphery arranged in close proximity to the side wall of the burner.

14. Combustion apparatus as defined in claim 11, wherein the means for delivering liquid fuel to the burner includes a-fuel inlet opening formed in a wall of the burner near the junction of the side wall and the bottom wall, and wherein the baffle means is arranged with its lower edge above and adjacent" said fuel inlet opening.

15. Combustion apparatus as defined in claim 11, wherein the baffle means in its entirety is arranged with at least one row of primary air inlet openings located above it and with at least one row of primary air inlet openings located below it.

BEN VALJEAN.

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