US3460895A

US3460895A - Device for gasifying and combusting light petroleum by utilizing air under pressure

Info

Publication number: US3460895A
Application number: US672228A
Authority: US
Inventors: Keizo Yamaguchi
Original assignee: Individual
Current assignee: Individual
Priority date: 1967-10-02
Filing date: 1967-10-02
Publication date: 1969-08-12
Anticipated expiration: 1986-08-12

Description

Aug. 12, 1969 KEIZO YAMAGUCHI DEVICE FOR GASIFYING AND COMBUSTING LIGHT PETROLEUM BY UTILIZING AIR UNDER PRESSURE Filed on. 2; 1967 HEIZO YAMAGUCHI.

uvvluroi BY a; W. uxhi'o United States Patent US. Cl. 431-116 2 Claims ABSTRACT OF THE DISCLOSURE This specification discloses a device for gasifying and cracking light petroleum, especially kerosene or light oil and directly combusting the cracked oil. The device comprises a blast type gas burner utilizing air under pressure ejected through a nozzle to introduce combustion flame. The blast type burner includes a fuel oil cracking portion for circulating combustion gas self-produced from the fuel oil so as to crack the fuel oil by means of said combustion flame and like reactions. The blast type burner also includes a burner body for introducing-the oil gas thereinto from said cracking portion, a Venturi tube therein for mixing said introduced cracked oil gas with air under pressure ejected through a nozzle Within one end of said Venturi tube, and a tire bridge spaced above the Venturi tube for reversing the direction of the combustible mixture gas flow from said Venturi tube. Thus the liquid oil is gasified and subjected to thermal cracking and like reactions to form cracked gas, and said self-produced combustion flame is circulated in the device to enable the thermally cracked gas to be more directly combusted. Furthermore, a part of the flame and the uncombusted gas, Which has passed through gaps between the supporting blades of the fire bridge into a secondary chamber of the burner, is efficiently and economically combusted in the secondary combustion chamber with the aid of secondary air introduced therein.

This invention relates to a burner, and more particularly to a device for gasifying, cracking and combusting light petroleum by utilizing air under pressure.

In burners for combusting liquid fuel, there have heretofore been two systems, one of which is the system in which liquid is sprayed mechanically or by contacting it with gas and further mixed With air to be burnt, and the other is the system in Which liquid is gasified and mixed with primary air Within the burner and then burnt While secondary air is further being supplied. The present invention is concerned With the latter system, of Which there are three types, a first of Which uses a Wick, a second is of nozzle ejection type, and a third is of pot Although the burner of the type which uses a Wick is very convenient to handle, Whereas it is disadvantageous in that it requires greater dimensions of the device if it is desired to combust a great deal of fuel and that it necessitates various additional designs to achieve complete combustion of the fuel.

Patented Aug. 12, 1969 In the burner of nozzle ejection type, fuel is completely gasified with the aid of external heat and pressure for combustion and therefore complete combustion can be effected with more case than in said type using a Wick, Whereas this nozzle ejection type is cumbersome in igniting operation. Moreover, this type requires addition of a means for continually gasifying fuel With external heat in order to maintain the combustion of the fuel in a steady state. This tends to cause a drawback that carbon is attached to the interior of the nozzle of the burner. Additionally, the burner of nozzle type not only requires a proportionally greater size if a greater quantity of combustion is desired, but also is more subject to failure Which means greater troubles for repairing.

The burner of the last-named type, namely, the pot type, is adapted to combust a great amount of fuel and is used with a means for discharging combustion exhaust gas outdoors, and this type is easy to handle and suitable for heating purpose. However, incomplete combustion is unavoidable with a result that carbon is deposited in the burner to necessitate cumbersome cleaning. Accordingly, if such type is used for the cooking purpose, the combustion chamber must be completely sealed and the heating must be indirectly effected to a great inconvenience.

It is therefore the primary object of the present invention to provide a burner device which eliminates the aforementioned drawbacks in the existing various types of burners for combusting liquid fuel, and in Which safe and economical oil such as light petroleum, especially such as kerosene or light oil, can be gasified with the aid of air under pressure and subjecting to reactions such as thermal cracking and the like While such gasified and cracked gases can be directly burnt Without being separated, whereby complete combustion can be attained from a minimum amount of oil and with the same degree of efliciency as when city gas or liquefied petroleum gas is used.

The burner according to the present invention is a device for gasifying and cracking light petroleum, especially kerosene or light oil and directly combusting the cracked oil, Which comprises a blast type gas burner utilizing air under pressure ejected through a nozzle to introduce combustion flame, said blast type gas burner including a fuel oil cracking portion for circulating combustion flame self-produced from the fuel oil combusted near the fuel oil filling port of the device so as to crack the fuel oil by means of said combustion cracking and like reactions, a burner body disposed Within said fuel oil cracking portion for introducing the oil gas thereinto from said cracking portion, a Venturi tube extending upwardly from said burner body for mixing said introduced cracked oil gas with air under pressure ejected through a nozzle projected into said burner body, and a fire bridge disposed above said Venturi tube for reversing the direction of the combustion flame flow from said Venturi tube, Whereby the liquid oil is gasified and subjected to thermal cracking and like reactions to form cracked flame, said self-produced combustion gas is circulated in the device to enable the thermally cracked gas to be directly combusted.

In order that the present invention may be clearly understood, the principle of the invention will be described. Light petroleum is thermally cracked at temperatures from 500 to 750 C. to become cracked gas while depositing carbon. At this time, if the pressure is too low, such reaction is eifected too severely. However, when the reaction is carried out in a stream of carbon dioxide and steam, thermal cracking and reduction of carbon dioxide take place concurrently and thereby there is produced carbon oxide rich cracked gas without carbon deposited. Thus the produced gas is a combustible gas composed of CH ,C ,H ,C H CO and so on. The rise of temperature to the necessary level for causing such thermal cracking can be obtained by exposing the top of the combustion flame to the fuel oil vapor near the filling port of light petroleum oil in the device, and at the same time carbon dioxide and steam are obtained as combustion products. The inventor considered that such self-produced combustion flame could be used to cause flame cracking to be created. On the other hand, the produced combustible gas is low in pressure, and therefore, for the purpose of its combustion, the most usual practice would be to employ a blast type gas burner in which small amount of air under pressure is ejected through a nozzle.

The blast type gas burner comprises a nozzle through which air under pressure is ejected, and a Venturi tube for sucking fuel cracked gas thereinto and mixing the gas with said air under pressure (primary air the amount of which is limited to about 50% of the theoretical volume for a complete combustion) to produce combustible mixture of gases. The combustion gas may be sucked into the Venturi tube by ejecting the air under pressure through the nozzle. In this respect, the blast type gas burner is opposite to the ordinary Bunsen type gas burner in which air is introduced into the Venturi tube by ejecting pressurized gas through the nozzle. In the blast type gas burner the amount of gas (in this case, air under pressure) ejected through the nozzle is much greater than the amount of gas (in this case, fuel gas) ejected through the nozzle of the Bunsen burner. Therefore, the sucking force is greater for the same ejection pressure in the former type than in the latter type, which means that the sucking force is much superior in the blast type burner if the construction is identical between the two types of burner. Thus the blast type burner can be designed so that a considerable amount of product 'of combustion flame is sucked together with fuel cracked gas. This sucking force provides the force to circulate the combustion flame.

A fire bridge is disposed above the Venturi tube in the blast type gas burner. The combustible mixture of gases discharged from the Venturi tube is combusted and the combustion gas is caused tostrike against the fire bridge and reverse its direction. The combusted gas mixtureis ready to be combusted to form fiame near the blades of the fire bridge. Then part of the combustion gas is sucked into gas sucking portions in the burner, which is the so-called combustion flame circulation. If the stream of the circulating combustion flame is exposed to fuel oil vapor (fuel oil has already been evaporated into gaseous state because of the high temperature near the filling port when it passes therethrough), there occur reactions such as thermal cracking to produce cracked gas. During the reaction, no carbon is produced, because in the flame has been already combusted completely and only CO is present in the reaction zone. The cracked gas together with the product of the combustion flame is sucked into the Venturi tube where these gases are mixed with primary air to form combustible mixture of gases, which is discharged from the Venturi tube to produce flame. Part of the combustion flame and the uncombusted gas is circulated in the burner while the other part of it goes outside the fire bridge to complete the combustion with secondary air.

If a number of metal blades are provided as support 4 means for the fire bridge to establish the stability of the flame, the primary combustion will continue smoothly. The metal blades must be properly spaced from each other so as not to prevent the flames from passing therethrough.

In this way light petroleum is turned into cracked gas by the combustion flame self-produced therefrom. The use of the blast type burner for combustion ensures as eflicient combustion of the oil as that of gas fuel such as city gas or liquefied petroleum gas. The pressure of air in use may sufliciently be 15 mm. aq. or higher as a result of experiments, and may preferably range from 40 mm. to mm. aq.

The invention will now be described more fully by way of example with reference to the accompanying drawings, in which:

FIG. 1 is a vertical sectional view showing the device embodying the present invention and taken along line IIII of FIG. 2; and

FIG. 2 is a horizontal sectional view taken along line I-I' of FIG. 1.

Referring now to FIGS. 1 and 2, a fuel oil supply pipe 1 is connected from a fuel oil supply source such as tank (not shown) through a circular outer wall 13 of the burner to a cylindrical portion 10 for gasifying fuel oil. A pressurized air conduit 2 having a pressurized air ejecting nozzle 3 at one end thereof is connected to a burner body or gas sucking portion 5 disposed concentrically within said fuel oil cracking portion 10, the other end of said air conduit 2 being connected to a blower 11 driven by blower driving motor 12.. A plurality of spaced gas sucking apertures 4 are formed along the lower periphery of the gas burner body 5, so that cracked oil in the fuel oil cracking portion 10 is introduced into the burner body 5. A somewhat tapered Venturi tube of combustible gas mixture forming portion 6 is upwardly extended from said burner body 5 so as to mix primary air ejected through the nozzle 3 with the gas introduced from the fuel oil cracking portion 10 through its sucking apertures 4 to form combustible gas mixture. Above the Venturi tube 6 is provided a fire bridge 8 which is supported by a number of upwardly inwardly inclined radial metal supports or blades 9. These metal supports or blades 9 serve to stabilize the flames formed by combustion of the gas discharged from the Venturi tube 6. The fire bridge 8 acts such that the combustion gas upwardly discharged from the Venturi tube 6 strikes against it and thereby the flow of combustible gas is reflected or reversed in downward direction, and the combustible gas is primarily combusted within the blades to produce flame Part of the reversed flame flow passes downwardly through a space 15 defined by the fire bridge 8 and metal blades 9 and circulates into the fuel oil cracking portion 10. The remaining part of the gas passes through the gaps formed by the spaced metal blades 9 into a second space 16 defined by the outer burner wall 13. In the lower portion of the burner which is defined by the outer wall 13 and fuel oil cracking portion 10, there is formed a secondary air passage 17 having secondary air outlets 7, which permits secondary air to pass therethrough so as to be mixed with the gas in said space 16 and combusted thereby to complete the combustion. The numeral 18 denotes a burner bed.

In operation, fuel oil such as light petroleum or especially kerosene or light oil is supplied from the fuel oil supply source through a flow rate adjust means and the oil supply pipe 1 into the oil cracking portion 10. Concurrently therewith, air under pressure or primary air is blown from the blower 11 through the conduit 2 and ejected through the nozzle 3 at the end of the conduit 2, whereby the pressure in the burner body 5 is reduced. The fuel oil supplied into the cracking portion 10 is cracked by the combustion flame, ignited by conventional electrodes (not shown), circulating therein and also brought into gaseous state by thermal cracking, and thus the cracked oil together with the product of the circulating combustion flame is sucked through the sucking apertures 4 in the burner body 5 which has already had its interior pressure decreased as described above. The gases introduced into the burner body 5 are brought into the Venturi tube 6 by the primary air ejected through the nozzle 3 and the gases and the primary air are mixed together in the Venturi tube to form combustible gas mixture, which in turn is discharged from the tube for combustion. The discharged combustion gas strikes against the fire bridge 8 to reverse its direction of flow downwardly. Part of the reverse gas flow is primarily combusted near the blades, and passes through the space to circulate into the cracking portion 10. The remaining part of the reversed gas flow passes through the gaps between the spaced metal blades 9 into the space 16, where secondary combustion is effected with the secondary air passing thereinto from the secondary air passage 17 through the secondary air outlets 7. Thus a complete combustion is efliciently achieved.

Combustion keeps on through repetition of the above operation. During the initial ignition, evaporation combustion is continued for several minutes until the fuel oil is cracked. The flow rate of air from the blower 11 may be adjusted in accordance with the flow rate of the fuel oil.

As discussed above, the present invention enables safe and economic fuel oil such as light petroleum, especially kerosene or light oil to be cracked and combusted as completely as city gas or liquefied petroleum gas, with a resultant high heat efiiciency. Moreover, the present invention provides a burner device which is much less complicated in construction than the conventional gas generators and which is safe and highly effective to use without the necessity of separating the gases and without any thermal loss due to the gas production.

While the invention has been described and shown with respect to a particular embodiment thereof for the purpose of illustration, it should be understood that the scope of the invention is not restricted only by the appended claims.

What is claimed is:

1. A gas burner device for gasifying and cracking light petroleum such as kerosene and other light oil, and directly and completely combusting the gasified-cracked oil, said burner device comprising in combination:

(a) a first relatively large cross-sectional, open ended housing member disposed vertically on a burner base to substantially encompass and help form a combined gasifying and comustion area;

(b) a second tubular member of much less crosssectional area forming a gasifying-cracking chamber concentrically spaced from and within said first housing, and having a closed bottom wall and an open upper end;

(c) transverse means having air passageways therethrough interconnecting said first and second tubular members;

(d) a third tubular member of still less cross-sectional area forming a burner body disposed upright and concentrically within said second tubular member, said burner body having an apertured lower periphery for introduction therethrough of cracked oil gas from the surrounding cracking chamber into the burner body;

(e) a Venturi tube superposed on and extending upward from the upper end of said burner body for mixing said gas with incoming air under pressure;

(f) fuel and air inlet pipes connected, respectively, with the gasifying-cracking chamber and with the burner body for introduction of the respective mediums;

g) said air inlet pipe disposed to axially direct primary air under pressure into the Venturi tube;

(h) a fire bridge comprising a transversely disposed plate member of a diameter not exceeding that of said second tubular member supported in spaced related above the Venturi tube by predetermined circumferentially spaced support members, and

(i) said fire bridge serving to reverse the direction of the flame and unburned combustion gas ejecting thereagainst from the Venturi tube, thereby subjecting the gasified oil to thermal cracking to form cracked gas, and said gas and air mixture and flame circulating and passing between said bridge support members interm'uring further with secondary air drawn in by the Venturi action through said air passageways in the means of paragraph (c) and thence circulating outwardly of the around the fire bridge and its support members in an upper portion of the first tubular housing member whereby it is efficiently, economically and completely burned.

2. A gas burner device including means for gasifying and cracking light petroleum, especially kerosense or other light oil, and directly and completely combusting the gasified-cracked oil, said burner device comprising in combination:

(a) a blast type gas burner including an outer peripheral, open-topped housing wall adapted to set upon a burner bed or base and vertically enclosing a composite gasifying and combustion area;

(b) a vertically disposed, generally cylindrical shaped inner housing forming a gasifying-cracking chamber substantially centered radially inward of said outer housing and having a closed bottom wall and an open top, said inner housing being supported intermediate the lower and upper ends of said outer housing by means of a perforated, transversely disposed plate interconnecting the upper portion of said inner housing and an intermediate portion of said outer housing wall;

(c) said gasifying-cracking chamber and transverse plate of paragraph (b) serving to divide said burner into a lower secondary air passage or chamber and an upper primary chamber having first and second combustion areas;

(d) an upright hollow tubular burner body supported centrally on the bottom wall of said inner housing, and having a plurality of apertures in the lower peripheral portion constituting inlets for introducing cracked oil gas into the burner body;

(e) a Venturi tube section disposed unitarily with and on the upper end of said cylindrical, burner body, for mixing said oil gas with primary air under pressure therein, said Venturi tube projecting above said transversely disposed perforated plate;

(f) a fuel oil inlet pipe whose outer end is adapted to be connected with an external source of fuel oil, said pipe extending into the burner through said outer housing wall and terminating in the lower portion within said inner housing gasifying-cracking chamber, but outwardly of said burner body disposed therein;

(g) an air inlet pipe having its inner end provided with a nozzle disposed within said burner body and directed into the Venturi tube section therea'bove, and having its outer end connected with means exterior of said burner for providing a primary source of pressurized air into said burner body and directed through said Venturi tube;

(h) a fire bridge spaced above said Venturi tube, said fire bridge comprising a transversely disposed, downwardly concave plate member supported by a plurality of support blades or members disposed circumferentially around said Venturi pipe in predetermined spaced relation to form the first combustion area of the upper chamber, and

(i) said fire bridge serving to reverse the direction of the flame and unburned combustion gas ejecting thereagainst from the Venturi tube, thereby subject References Cited ing the gasified oil to thermal cracking to form UNITED STATES PATENTS cracked gas, and said gas and air mixture and flame circulating and passing between said bridge support g z members intermixing further with secondary air 5 2195617 4/1940 s g fi 431 116 drawn in by the Venturi action through said per- 2275678 73/1942 Mason X forated transverse plate and thence circulating into 3:361:18? 1/1968 EIIIL;

the second combustion area outwardly of the fire bridge and its support membersin the upper priv mary chamber, whereby it is further efficiently, eco- 10 nomically and'completely burned. 431 335 CHARLES J. MYHRE, Primary Examiner US. Cl. X.R.