Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23D—BURNERS
  • F23D11/00—Burners using a direct spraying action of liquid droplets or vaporised liquid into the combustion space
  • F23D11/36—Details, e.g. burner cooling means, noise reduction means
  • F23D11/38—Nozzles; Cleaning devices therefor

Definitions

• This invention relates generally to burner nozzles which can be adjusted to alter the direction of flow of fluid passing through the nozzle and specifically is. an improved adjustable burner nozzle which enables more rapid heat dissipation from the nozzle.
• the improved nozzle features an infinitely adjustable angle resulting in improved temperature distribution.
• Burners are used extensively in industrial and other applications to produce heat in a furnace or other such apparatus. Generally fuel and oxidant flow through the burner body, either separately or as a mixture, and are injected, through a nozzle, into a furnace zone wherein they combust to produce heat. Often the nozzle employed is an adjustable nozzle which can be adjusted to alter the direction of flow of the fluid so as to change the direction or shape of the resulting flame.
• an adjustable burner nozzle comprises a threaded piece with an angled passage through it.
• the threaded piece is screwed into a burner passage at the discharge end of the burner.
• the angled passage changes its flow direction.
• Such threaded pieces may also be removed for cleaning or replacement, or to change the angle of the fluid flow with respect to the burner face. In the latter case the threaded piece is removed and replaced with another threaded piece having a passage through it at the desired angle.
• Temperatures at the burner face where the nozzle is located are quite high, generally exceeding 2500 ⁇ F, and much of this heat is radiated to the burner face and the nozzle. It is imperative that the nozzle be effectively cooled because the greater the temperature at which the nozzle is operated, the shorter the effective life of the nozzle. Furthermore, high heat is especially deleterious for an adjustable nozzle because the high heat may cause the threaded area to scale or otherwise seize thus rendering the nozzle, non-adjustable and unremovable. The problem is exacerbated by the fact that cooling water cannot be piped as close to an adjustable nozzle as it can be to a ixed nozzle because the cooling water passage must not interfere with the threaded seat.
• a particular problem with the conventionally employed adjustable nozzle is that the contact between the threaded nozzle piece and the threaded seat is necessarily not good unless the nozzle is fully screwed into the seat and set there with relatively high or tight tension. However this situation occurs only at one nozzle setting. All other nozzle settings around the 360 degree arc must be at loose tension. This is troublesome because the loose tension and resulting poor contact between the threaded nozzle and the threaded seat results in an impediment to heat transfer, i.e. heat dissipation from the nozzle to the burner body and to the cooling fluid.
• An adjustable burner nozzle having improved heat transfer comprising:
• a spherical piece having a smooth spherical surface and having a nozzle passage completely therethrough, moveably seated within said burner passage and in full surface contact with said smooth concave portion; and (c) means to secure said spherical piece In full surface contact with said smooth concave portion.
• full surface contact means the positioning of two mated surfaces together in mated relation with enough space between the surfaces to.allow relatively unhindered movement of one surface relative to the other, i.e. the space between the mated surfaces does not appreciably exceed the minimum space required for relatively unhindered movement.
• Figure 1 is an axial cross-sectional representation of one . referred embodiment of the adjustable burner nozzle of this invention.
• Figure 2 is a view of the Figure 1 embodiment as viewed from the furnace zone.
• Burner passage 2 which communicates with burner discharge end 3 so as to discharge fluid passing through burner passage 2 into furnace zone 4.
• Burner passage 2 is also connected to a source of fluid such as by manifold 5.
• the fluid for passage through burner passage 2 may be oxidant such as air, enriched air, or oxygen, or it may be fuel such as natural gas or coke oven gas, or it may be a mixture of fuel and oxidant.
• Burner passage 2 is generally cylindrical although it may be of any effective geometry.
• burner passage 2 Recessed from burner discharge end 3, the walls of burner passage 2 form smooth concave portion 6 which is shaped to matingly receive a spherical object.
• the cross-sectional area of burner passage 2 increases upstream of concave portion 6 such as is shown by portion 7 of burner passage 2.
• This enlarged portion 7 is advantageously employed to increase the range of positions to which the nozzle may be adjusted and thus increase the flexibility and utility of the invention.
• spherical piece 8 having a smooth spherical surface.
• spherical piece 8 is a complete sphere.
• Sphere 8 is not fixed in position but rather is free to move in all rotational directions.
• Sphere 8 is seated in full surface contact with smooth, concave surface portion 6.
• Sphere 8 and the other burner parts are generally made of copper or copper-nickel alloys. Copper is the preferred material of construction.
• nozzle passage 9 which is generally of circular or oval cross-section but which may have any effective geometry. In practice, a cross-sectional area of
• nozzle passage 9 has been usefully employed.
• the length of the nozzle passage must significantly exceed its cross-sectional widest diameter.
• the nozzle passage length is at least three times greater than the nozzle passage diameter at its widest point when the nozzle passage has a constant cross-section through the spherical piece.
• Nozzle passage 9 may also be converging or diverging.
• FIG. 1 illustrates locking ring 10 which is a preferred such securing means.
• locking ring 10 is shaped to mate with sphere 8 and is also mated by means of a thread to burner head 1. Locking ring 10 is screwed into place by placing wrench face pins into wrench receivers 11 and turning until sphere 8 is secured in surface contact with concave portion 6.
• the benefits of this invention are attained by the high contact area between sphere 8 and burner head 1 which is cooled during combustion operation, generally by flow of cooling water. Because this contact area remains high and constant irrespective of the position of sphere 8, heat is transfered at a relatively high rate from the nozzle to the coolant. Thus the nozzle is operated at a temperature lower than that at which conventional adjustable burner nozzles may be operated. This increases the working life of the nozzle and markedly reduces the chance that the nozzle may seize in place.
• fuel, oxidant or a mixture thereof passes through burner passage 2 and through nozzle passage 9.
• the orientation of nozzle passage 9 determines the angle and direction at which the fluid is injected into furnace zone 4.
• the heat radiated to sphere 8 is conducted through the entire mated area of the spherical surface and concave surface 6 from sphere 8 to burner head 1.
• the burner head is in turn cooled generally by flow of cooling water through it.
• Another benefit of this invention is the ability to change not only the direction of the fluid flow, but also the angle of the fluid flow relative to the burner face, without need to change the nozzle.
• Conventional adjustable burner nozzles have a fixed angle of injection, for example 30 degrees. In order to inject fluid into the furnace zone at 15 degrees, one had to remove the 30 degree nozzle and replace it with the 15 degree nozzle. However, with the nozzle of this invention one merely rotates sphere 8 to the desired angle, such as by moving sphere 8 to move nozzle passage 9 along axis line A-A in Figure 2. Directional changes are made by moving sphere 8 so that nozzle passage 9 moves in a circular manner as observed from the vantage point of furnace zone 4.
• spherical piece 8 is as a complete sphere as is illustrated in the drawings. However, it can be appreciated that spherical piece 8 need not have a completely spherical surface. A spherical surface is required only so far as is necessary to mate in full surface contact with concave portion 6 and to rotate in such a way as to achieve the desired adjustability.
• EXAMPLE 1 The most severe heat dissipation conditions for a burner nozzle exist when the furnace is at an elevated temperature but there is no flow of fuel or oxidant through the burner. These conditions exist when the furnace zone has reached the desired temperature and no more heat is needed, or when the furnace is shut down. In these situations the temperature in the furnace zone remains high and considerable heat is radiated to the burner nozzle, but there is no flow of fluid through the nozzle to remove heat.
• the burner nozzle of this invention and, for comparative purposes, a conventional adjustable burner nozzle were tested for heat dissipation under such severe no-flow conditions.
• Two oxidant passages were each outfitted with an adjustable burner nozzle of this invention of a design substantially similar to that shown in the drawings.
• the six other oxidant passages were outfitted with conventional adjustable burner nozzles having a threaded seat.
• the furnace was brought to a temperature ' of 2320°F and held constant with a water in temperature of 57°F.
• the water out temperature with a water flowrate of 2.0 gallons per minute was 73°F when a steady state temperature was achieved in each of the eight burner nozzles.
• the steady state temperature of the two burner nozzles of this invention was 320 ⁇ F while the steady state temperature of the conventional burner nozzles was 420 ⁇ F.
• the burner nozzles of this invention under comparable severe conditions operated at a temperature 100°F less, or 24 percent less, than the temperature at which conventional adjustable burner nozzles operated.

Landscapes

• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Nozzles For Spraying Of Liquid Fuel (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=24732426

Family Applications (1)

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• 1985
  • 1985-12-11 EP EP19860900455 patent/EP0204825A1/en not_active Withdrawn
  • 1985-12-11 WO PCT/US1985/002421 patent/WO1986003573A1/en not_active Application Discontinuation
  • 1985-12-11 ES ES1985296368U patent/ES296368Y/es not_active Expired
  • 1985-12-11 JP JP50024685A patent/JPS62501439A/ja active Pending
  • 1985-12-11 BR BR8507116A patent/BR8507116A/pt unknown

Non-Patent Citations (1)

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