US1754405A - Combined coal and gas furnace - Google Patents

Description

April 15, 1930. L, SHARP 1,754,405

COMBINED COAL AND GAS FURNACE Filed April 19, 1929 2 SheetsSheet 1 ll i 25 1 2 8 i 4m 25 z/ J 7 2 EI/fl 19 7 /a 4 j: {a 619i 4-0 35 lll gwvcantoc loaid 6. 4247 11.

dummy April 15, 1930.

' 2 Sheets-Sheet 2 Filed April 19, 1929 6 z a, W. a 1 z 5 ll j INH 3 w 6 7 I i 5 5 m 1 W Patented Apr. 15, 1930 UNITED STATES LOUIS n. SHARP, on

PATENT OFFICE DENVER, COLORADO comnmnn cont AND ens summon Application filed April 19,

residences is becoming very general andin many places the ordinary coal furnace isemployed by merely substituting a gas burner for the grate. Such converted furnaces are not entirely satisfactory because if the furnace is properly designed for burning coal, it will not operate as efficiently with gas as itwould if it were designed with particular reference to this type of fuel. It is well known that when coal is employed for fuel, there is a gradual accumulation of soot and dust within the flues through whichthe gases of combustion pass and the furnace has to be designed in such a way that a large amountof this material can be collected without interfering seriously with the draft and operation of the furnace. The fact that coal produces a soot deposit as above mentioned, makes it necessary to have the flue passages shorter and straighter than they would have to be if a fuel Were used that did not produce such deposits. When gas is employed, there is very little, if any, soot or other material deposited on the inside of the furnace and it is therefore possible to have longer and more 5 tortuous flue passages and by this means the a 1929. Serial No. 356,382.

whereby adjustments can be made in the areas of the flue passages, so as to make the furnace suitable for either type of fuel.

a It is another object of this invention to produce a furnace that shall have an exceptional- ,0

1y large radiation surface in comparison with its size so that the heat produced by the fuel will be as completely as possible transferred to the surrounding a1r.

It is a still further object of this invention to produce a furnace which shall be so designed and constructed, that it will have ample space for the hot air to pass through the interior of the furnace shell and which will direct the passage of the air in such a way 0 that all of the air will come in contact with the heated surfaces of the furnace so as to secure an efiicient and complete transfer of heat fromthe furnace to the air.

The above and other objects which may appear as the description proceeds are attained by means of a construction and an arrange ment of parts that will be described in detail, reference for this purpose being had to the accompanying drawings in which the pre- 7 ferred embodiment thereof has been illustrated, and in which:

Fig. 1 is a vertical section through the furnace.

Fig. 2 is a transverse section taken on line 2--2, Fig. 1;

Fig. 3 is a section taken on line 3 3, Figs. 1 and 4, and shows the two radiator sections;

Fig. 4 is a section taken on line 4-4, Fig. 3,

parts of the radiator section being broken 30' away;

Fig. 5 is a section similar to that shown in Fig. 1, but showingthe gas burner removed and replaced by a water pan for moistening the air; and

Fig. 6 is a section taken on line 6-6, Fig. 5.

In the drawings reference numeral 1 represents the ash pan section of the furnace on which the combustion section is supported. This combustion section has a cylindrical 90 portion 2 which forms the wall of the fire pot and whose upper edge is outwardly flared so as to provide an inclined flange 3 whose outer edge terminates in an upwardly extending roove 4, for the reception of the wall memher 5, which is made in the form of a ring. The upper end of section 5 is provided with a roove 6 in which the lower edge of the raiator section 7 rests. This radiator section has an inwardly curved upper end portion 8 which terminates in a downwardly extending circular wall 9. A crown plate or dome 10 is supported by the upper ends of the tubes 11. These tubes have their lower ends connected with the upwardly extending tubular nipples 12 and have their upper ends connected with similar downwardly extending nipples 13, which are formed integral with the dome. The central part of the dome is preferably concave on its upper surface and convex on its lower surface, but may be straight or upwardly curved. The dome member is provided with a downwardly inclined flange 14 whose outer edge terminates a short distance from the inner surface of wall 7. This flange is provided with a plurality of spaced notches 15 and supports a ring-like member 16, which is also provided with a plurality of notches corresponding in number and position with the notches 15. When the ring is rotated, it can be moved into such a position that the solid portions overlap the notches 15, or into such a position that the notches 15 are entirely uncovered. The upper surface of flange 14 is provided with a lug 17 that'serves as a stop and which limits the rotary movement of member 16. A handle 18 is secured to the ring 16 and serves as a convenient means for rotating the ring. A clean-out opening 19 is provided in the radiator section 7 directly in front of handle 18 so that a proper tool may be in sorted into this opening for rotating the ring. The object and function of this ring will be more clearly explained as the description proceeds. The curved part 8 of the radiator section 7 is provided with two diametrically spaced upwardly projecting circular nipples 20 with which the nipples 21 that are secured to the lower surface of the radiator section 22 cooperate for holding the latter section in place and for connecting its interior with the interior of radiator section 7. The upper surface of the annular radiating section is provided with two upwardly extending circular nipples 23 which are adapted to receive the downwardly extending nipples 24 of the flue radiator 25. One end of this flue radiator is provided with a hinged door 26 and the other end is connected with the flue 27 "which extends to the Smokestack or chimney.

The annular radiator section 22 is provided with two diametrically located partitions 28 which divides the interior thereof into two separate compartments in the manner indithe manner shown in Fig. 0.

cated quite clearly in Fig. 4. The flue gases enter this radiator section through openings 29 and after passing half ways around the section leave through the openings 30, from which they pass into the flue radiator 25. Clean-out openings 31 are provided at opposite sides of the radiator section.

This furnace is provided with a recess which has been designated by A and which is located directly beneath the door 32 of the combustion chamber and above the wall 33 of the ash chamber. When the furnace is used with coal, this recess serves as a chamher in which the water pan 34 is located in If the furnace is to be used with as fuel, the pan 34 is removed and replaced by a gas burner which has been shown in Fig. 1 and which has been designated by reference numeral 35. The wall 2 of the fire pot is provided with an opening 36 of the proper size to receive the inner end of the gas burner. \Vhen the gas burner is removed, or when the furnace is used with coal as fuel, a plate 37 is put in place in the opening 36 in the manner shown in Figs. 5 and 6. When the furnace is used with gas the water pan 34 is moved to the location shown in Fig. 1 so that it will not interfere with the operation of the furnace. The furnace is provided with a grate 38 which can be in place even when the furnace is operated by means of gas and therefore the change from gas to coal, or from coalto gas, can be readily made. When the furnace is used with gas as fuel, the ring 16 is rotated into such a position that it covers the openings 15 and there is then left a narrow annu-- lar space between the inner surface of the wall 7 and the outer edge of ring 14 through which the gases must pass. This throws the heated gases outwardly against the outer surface of the radiator section and brings them into close contact therewith, so that a good heat exchange takes place. WVhen gas is used for fuel there is, as above explained, very little if any soot deposited in the flue chambers, but whencoal is used a lot of soot is formed and deposited. When coal is employed, the annular space about the outside of rim 14 soon becomes filled so as to destroy the draft and it is therefore necessary when changing from gas fuel to coal to move the ring 16 to such a'position that the notches in this ring register with the openings 15 and by this means larger openings are produced through which the gases of combustion pass and this prevents the clogging due to the accumulation of soot. In order to keep the space about ring 14 clean. I have provided ring 16 with a plurality of downwardly extending lugs 39 that project over edge of the flange and serve to wipe the soot away fro-m these edges when the ring is rotated.

When the furnace is in operation, the heated air passes from wit-hin'the shell 40 to the the outside of the combustion chamber and around and about the radiator sections and absorb the heat from the latter. Owing to the big area of the air'passages, the furnace has a free circulation of air and at the same time brings the air into such close contact with the walls of the furnace that it will quickly attain a high temperature.

In the above description gas has been men tioned as the fuel that can be employed in the place of coal, but it is evident, however, that oil may be used as well as gas.

Having described the invention what I claim as new is: V

1. A furnace having a fire pot, formed in part by a cylindrical member (5) and a dome member (10), said dome member having its outer edge in close proximity to but spaced from the inside of thecylindrical member whereby an annular passage is formed for the passage of flue gases, said dome member having its outer edge provided with openings and means for varying the effective area of said openings.

2. A furnace having a fire pot, formed in part by a cylindrical member (5) and a dome member (10), said dome member having its outer edge in close proximity to but spaced from the inside of the cylindrical member whereby an annular passage is formed for the passage of flue gases, said dome member having its outer edge provided with openings and means for varying the effective area of said openings, said means comprising a ring provided with openings adapted to register with the openings in the dome member when in one position and with solid portions adapt ed to form closures for the openings when the ring is in another position.

3. A furnace having a fire pot, formed in part by a cylindrical member (5) and a dome member (10), said dome member having its outer edge in close proximity to but spaced from the inside of the cylindrical member whereby an annular passage is formed for the passage of flue gases, and means for removing accumulations of soot from said passage.

4:. A furnace having a fire pot, formed in part by a cylindrical member (5) and a dome member (10), said dome member having its outer edge in close proximity to but spaced from the inside of the cylindrical member whereby an annular passageis formed for the passage of flue gases, and means for removing accumulations of soot from said passage, said means comprising a ring adapted to rest on the upper surface of the dome adjacent the edge thereof and a plurality of lugs secured to the ring, said lugs projecting downwardly into the passage whereby when the ring is rotated about its center, the lugs will clean the passage. i r a 5. A furnace having a fire pot formed from a cylindrical member (2) whose upper end terminates in an outwardly extending flange (3), said flange having a plurality of spaced openings, a dome member having openings corresponding in number and position with the openings in the flange, tubular members extending from the upper surface of the flange to the under surface of the dome, said tubular members being in axial alignment with the openings, a cylindrical member (5) supported on the flange and extending above the dome, the upper end of this member being curved inwardly and thence downwardly, and having its edge resting on the upper surface of the dome, the diameter of the dome being slightly less than the inside diameter of the cylindrical member, but larger than the inside diameter of the downwardly extending upper portion whereby an annular chamher is formed that is in communication with the fire pot throughthe passage about the outer edge of the dome, an annular hollow radiator section supported from the upper curved end of the ring-like member and connected with the interior of the latter and a flue section connected with the interior of the annular radiator section.

6. A furnace having a fire pot formed from a cylindrical member (2) whose upper end is flared outwardly so as to form a flange (3), an ash receptacle section located underneath the cylindrical member and eccentric with respect thereto, the lower end of the cylindrical member having an opening, a gas burner resting on the uppersurface of the ash receptacle, the end of the burner extending inwardly into the openingga radiator section located above the fire pot, means for deflecting flue gases outwardly against the inner surfaces of the radiator section, and means for varying the effectiveness of the deflecting means.

7. A furnace having a fire pot formed in part by a cylindrical member (2), whose up per end is flared outwardly so as to form a flange (3), a cylindrical wall member resting on the upper surface of the flange, the upper end of said wall member being inwardly and downwardly curved, a dome member located above the upper surface of the flange with its upper surface inv contact with the lower end of the downwardly extending end of the upper part of the cylindrical member, a plurality of tubular supports extending from the flange to the dome and serving as supports for the latter, the diameter of the dome being greater than the diameter of the downwardly extending portion of the cylindrical wall member and somewhat less than the inside diameter of the cylindrical wall member whereby an annular passage is formed between the combustion chamber below the dome and the compartment above the dome, the edge of the dome having a plurality of radially spaced openings, and a ring supported on the dome and movable with respect thereto, said ring having openings adapted to register with the openings in the dome when in one position and solid portions adapted to close the openings When in another position.

In testimony whereof I aifix my signature.

LOUIS E. SHARP.

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