KR20230156106A - Fluid burner head and use of fluid burner head - Google Patents

Abstract

A fluid burner head (9) for a fluid combustion unit (1) and use of the fluid burner head (9) in a fluid combustion unit (1) are provided. The fluid burner head 9 includes a body 11, which includes a hollow tube 13 for transporting the fluid to be burned into the combustion chamber 5 and an upper end 25 of the tube 13 that is at least partially closed. Includes cap (15). The wall 17 of the tube 13 includes a plurality of rows 29 of holes 27, which rows 29 extend around the longitudinal central axis C of the fluid burner head 9. The hole 27 allows the fluid to be burned to flow from the inside 49 to the outside 51 of the tube 13. The fluid burner head (9) is characterized in that it further comprises an annular first projection (39) extending around the longitudinal central axis (C) of the fluid burner head (9). The first protrusion 39 is located above the uppermost row 29a of the holes 27 of the tube 13, obliquely upward from the outer surface 43 of the body 11, and towards the longitudinal center of the fluid burner head 9. It protrudes at an angle α with respect to the axis (C), with 0 < α < 90 degrees.

Description

Fluid burner head and use of fluid burner head

The present invention relates to a fluid burner head for a fluid combustion unit and its design. The invention also relates to the use of such a fluid burner head in a fluid combustion unit for burning boil-off gases from fuel tanks on board a ship.

In various situations, combustion of a fluid, such as a gas or a mixture of gas and liquid, may be desired. For example, gas combustion units are typically installed on board LNG carriers, ie tank ships arranged to transport liquefied natural gas (LNG). LNG, which has a vaporization temperature of -160°C at atmospheric pressure, is stored in the tank. Even if these tanks are insulated, some evaporation of the LNG will inevitably occur, forming so-called boil-off gas. These evaporative gases increase the pressure within the tank and must be vented from the tank for safety reasons. The boil-off gas removed from the tank can be re-liquefied, returned to the tank, used as fuel on an LNG carrier, or combusted by a gas combustion unit.

A gas combustion unit may typically include a gas burner head extending into a combustion chamber. The gas to be burned is supplied to the combustion chamber through the gas burner head and is ignited and burned in the combustion chamber. Known gas burner heads comprise a perforated tube whose end is closed with a cap. Gases are transported through a tube, through a perforation in the tube, into a combustion chamber, where combustion occurs in a flame. When the gas pressure is relatively high, the gas will be supplied at high speed through the perforation, resulting in a flame being generated at some distance from the gas burner head. Additionally, the gas flow inside the tube will cool the gas burner head. As a result, the temperature of the gas burner head will remain low enough to prevent damage. However, when the gas pressure is relatively low, the gas will be supplied at low speed through the perforation, resulting in a flame occurring close to the gas burner head. Additionally, cooling of the gas burner head due to gas flow inside the tube will be reduced. This can cause the gas burner head to become very hot and damaged, typically in the area close to the closed end of the tube.

The object of the present invention is to provide a fluid burner head and the use of the fluid burner head that at least partially solves the above problems. The basic concept of the invention is to provide a fluid burner head with means for forcing the fluid to be burned and the resulting combustion flame further away from the fluid burner head. Fluid burner heads and the use of fluid burner heads to achieve the above objectives are defined in the appended claims and discussed below.

A fluid burner head for a fluid combustion unit according to the invention includes a body. The body includes a hollow tube or pipe for conveying the fluid to be burned into the combustion chamber, and a cap that at least partially closes the upper end of the tube. The tube further includes a lower end for receiving fluid within the tube, i.e., inside the tube. The wall of the tube includes a plurality of rows of holes, which extend around the longitudinal central axis of the fluid burner head. The holes allow the fluid to be burned to flow from the inside of the tube to the outside, i.e. through the wall of the tube. The fluid burner head is characterized in that it further comprises an annular first protrusion or protrusion extending about the longitudinal central axis of the fluid burner head. The first protrusion protrudes above the uppermost row of holes in the tube obliquely from the outer surface of the body in a direction away from the lower end of the tube, i.e. upward, at an angle α with respect to the longitudinal central axis of the fluid burner head, 0 < α < It's 90 degrees. The top row of holes is the row of holes located closest to the cap.

The first protrusion may include opposing first and second edges. The first and second edges may be annular and extend along one another. The first protrusion may engage the body directly or indirectly along a first edge and the second edge may be free.

In this specification, the terms “combust” and “burn” and variations thereof are used and are intended to have the same meaning.

The fluid may be a gas or a mixture of gas and liquid. As an example, the fluid may be boil-off gas from an LNG tank, such as methane or a mixture of methane and nitrogen.

The tube may include a cylindrically formed mesh.

The tube may be a perforated tube and the opening may be a perforation in the tube.

The tube may be elongated, may have any suitable wall thickness, and may have any suitable cross-section such as circular, oval, or polygonal.

The tube may be made of any suitable material such as metal, such as carbon steel, stainless steel or aluminum.

The longitudinal central axis of the fluid burner head may coincide with the longitudinal central axis of the tube.

A plurality of columns refers to two or more columns in this specification.

The holes, openings, openings or perforations in the tube may or may not all be of the same size and/or shape, and may have any suitable size and shape, such as circular, oval or polygonal. Additionally, the holes may or may not be equally spaced.

“Annular” need not mean a circular longitudinal extension, but can mean any closed longitudinal extension, such as an elliptical or polygonal extension.

In this specification, “top”, “top”, “bottom”, “bottom”, “top”, “bottom”, etc. refer to the fluid burner head when the fluid burner head is oriented in its normal use state. Additionally, “top/bottom” means disposed furthest/closest to the surface or ground on which the fluid combustion unit including the fluid burner head is disposed.

As mentioned above, the cap at least partially closes the upper end of the tube. As used herein, a top that is only partially closed can mean that gas can pass from within the tube to the outside of the tube, for example through an opening in the cap or an opening between the tube and the cap.

The first protrusion may or may not have a uniform cross-section along its longitudinal extension, for example a constant width and/or thickness. As an example, the first protrusion may be formed as a skirt or flange. If the width and thickness are zero along one or more portions of the longitudinal extension, the first protrusion may be considered discontinuous.

The first protrusion forces the fluid to be burned away from the fluid burner head even when the fluid is supplied at a relatively low speed through the hole in the tube to lower the temperature of the fluid burner head and thus reduce the risk of damage to the fluid burner head. It is placed.

The tube and cap may be formed integrally. However, according to one embodiment of the present invention, the tube and cap are formed separately. Therefore, the tube and cap can be replaced independently of each other if necessary.

The tube and cap may be made from the same material. However, according to one embodiment of the invention, the cap and tube are made of different materials. This may enable a more flexible structure of the fluid burner head. The cap may be made of any suitable material such as refractory concrete or metal, such as carbon steel, stainless steel or aluminum.

The first protrusion may be positioned anywhere between the top row of holes in the tube and the top of the fluid burner head. However, according to one embodiment of the invention, the first protrusion protrudes from the outer surface of the body at the boundary between the tube and the cap. If the first protrusion is not in place, the temperature at the interface between the tube and the cap tends to be locally relatively high. Accordingly, by placing the first protrusion at the tube-cap boundary, the risk of damage to the fluid burner head can be minimized.

The fluid burner head may be configured such that the tube and the first protrusion are formed separately. Accordingly, if the first protrusion is worn, it can be replaced with a new one without having to discard the tube and possibly the cap.

The tube may have a cross-section that varies along its longitudinal central axis. However, according to one embodiment of the invention, the upper portion of the tube containing the hole has an essentially uniform cross-section along the central longitudinal axis of the fluid burner head. This can facilitate the production of fluid burner heads.

The fluid burner head may further include an annular support extending about a longitudinal central axis of the fluid burner head. The support may be connected to the first protrusion and engage the body of the fluid burner head to secure the first protrusion to the body. This design may facilitate placement of the first protrusion on the body. Like the first protrusion, the support may or may not have a uniform cross-section along its longitudinal extension and may be continuous or discontinuous.

The fluid burner head may further include an annular second protrusion extending about the longitudinal central axis of the fluid burner head. The second protrusion may protrude from the outer surface of the body between the first protrusion and the uppermost row of holes in the tube. The first protrusion may or may not protrude beyond the second protrusion. The second protrusion forces the fluid to be burned away from the fluid burner head even when the fluid is supplied at a relatively low speed through the hole in the tube, lowering the temperature of the fluid burner head and thus reducing the risk of damage to the fluid burner head. It can be helpful.

The second protrusion may protrude from the outer surface of the tube to locally shield the tube in areas where temperatures of the tube tend to be relatively high. This minimizes the risk of tube damage.

As previously discussed, the fluid burner head may include an annular support extending about a central longitudinal axis of the fluid burner head. The support may be connected to both the first protrusion and the second protrusion and engage the body of the fluid burner head to secure the first and second protrusions to the body.

Regardless of whether the support is connected only to the first protrusion or also to the second protrusion, the support can couple to the body in a variety of ways. By way of example, the support may be screwed snugly onto the body such that it is held in place by friction. However, according to one embodiment of the invention, the support is clamped between the cap and the tube. This can enable precise positioning of the first protrusion and, if applicable, the second protrusion as well as a secure connection between the body of the fluid burner head and the support.

The cap can be designed in a variety of ways. According to one embodiment of the invention, the cap includes an upper part and a lower part, the lower part protruding into the tube. This can enable safe and accurate coupling between the cap and the tube.

The lower portion of the cap may include a portion that tapers in a direction away from the upper portion of the cap. For example, the lower portion may be conical or, in some cases, truncated conical. This may result in the flow area inside the tube perpendicular to the longitudinal central axis of the tube being reduced towards the cap, i.e. towards the top of the tube. This may then result in the fluid flow rate inside the tube increasing in the direction towards the cap, i.e. towards the top of the tube. Accordingly, this design may make it possible to force the fluid supplied through the upper hole of the tube and the resulting combustion flame further away from the fluid burner head. Accordingly, the temperature of the fluid burner head and the risk of damage to the fluid burner head can be lowered, especially when the fluid is supplied at a relatively low pressure through the tube.

The fluid burner head may be designed so that the outer circumference of the upper portion of the cap is larger than the inner circumference of the tube. This prevents the upper part of the cap from being received in the tube, which can enable a precise and secure fit between the cap and the tube.

The fluid burner head according to the invention can be used in a fluid combustion unit for burning boil-off gases from fuel tanks onboard ships.

The advantages discussed above of the various embodiments of the fluid burner head according to the invention can naturally be transferred to various embodiments of use according to the invention.

Further objects, features, aspects and advantages of the present invention will emerge from the following detailed description and drawings.

The present invention will now be explained in more detail with reference to the attached schematic diagram.
1 is a schematic cross-sectional view of a fluid combustion unit.
Figure 2 is a schematic perspective view of the fluid burner head of the fluid combustion unit of Figure 1;
Figure 3 is a schematic side view of the fluid burner head of Figure 2;
Figure 4 is a schematic cross-sectional view of the fluid burner head of Figure 2;
Figure 5 is a partially enlarged view of the cross-sectional view of Figure 4.
Figure 6A is a schematic side view of the configuration of the fluid burner head of Figure 2;
FIG. 6B is a schematic top view of the configuration of FIG. 6A.
Figure 6c is a schematic cross-sectional view of the configuration of Figure 6a.

1 shows a fluid combustion unit 1, more specifically a gas combustion unit. A fluid or gas combustion unit 1 is arranged on board a ship (not shown), in particular an LNG carrier, for burning boil-off gases from one or more LNG tanks on the ship. The fluid combustion unit 1 includes a fluid burner system 3, an air supply system (not shown), a combustion chamber 5 and a stack 7. The boil-off gas from the LNG tank(s) is supplied to the fluid burner system (3) and further to the combustion chamber (5), where it is ignited and burned. The combustion products leave the combustion chamber (5) and mix with cool air in the stack (7) before leaving the fluid combustion unit (1). The structure and function of the fluid combustion unit are well known in the art and will not be described in further detail herein.

The fluid burner system 3 comprises a fluid burner head 9, more specifically a gas burner head, which is shown in more detail in FIGS. 2 to 6 . The fluid burner head (9) comprises a body (11) comprising a hollow, elongated stainless steel tube (13) and a solid cap (15) made of refractory concrete. Tube 13 and cap 15 are separate, separable elements having a circular circumference when viewed along the longitudinal central axis C of the fluid burner head 9.

The tube 13 has a wall 17 of uniform thickness along and around the longitudinal central axis C of the fluid burner head 9 . Referring to Figure 4, it includes a lower part 19, a lower part 21, an upper part 23 and an upper part 25 which are sequentially arranged along the longitudinal central axis C. The upper portion 23 of the tube 13 includes a plurality of circular holes 27 extending through the wall 17 of the tube 13. These holes 27 are arranged in rows 29 at equal intervals. The rows 29 of holes 27 are mutually parallel and extend at equal intervals around the longitudinal central axis C of the fluid burner head 9.

Referring to FIG. 5 , the cap 15 includes an upper portion 31 and a lower portion 33 disposed concentrically with respect to the longitudinal central axis C of the fluid burner head 9 . The boundary between the upper part 31 and the lower part 33 of the cap 15 is shown in broken lines. The upper part 31 has the basic shape of a circular plate with a constant cross-section along the longitudinal central axis C. The lower part has the basic shape of a truncated cone with a circular cross-section that decreases along the longitudinal central axis C in the direction away from the upper part 31 of the cap 15 . The maximum cross-section of the lower part 33 is smaller than that of the upper part 31.

As is clear from the drawings, especially FIG. 5 , the cap 15 closes the upper end 25 of the tube 13 . The lower portion 33 of the cap 15 has a maximum circumference smaller than the inner circumference of the tube 13 and is received within the tube 13 . The upper portion 31 of the cap 15 has a circumference that is essentially equal to the outer circumference of the tube 13 and is larger than the inner circumference of the tube 13 . The upper part 31 of the cap 15 is disposed outside the tube 13 and abuts its annular edge defining the upper end 25 of the tube 13 . Due to the above-specified relative dimensions of the tube 13 and the cap 15 , an annular groove 35 is formed between the lower part 33 of the cap 15 and the tube 13 .

Referring to FIGS. 5 and 6A-6C, the fluid burner head 9 includes an annular support 37 in the form of a flat circular ring made of stainless steel, and an annular first protrusion 39 in the form of a circularly extending skirt made of stainless steel. ), and an annular second protrusion 41 in the form of a very short tube made of stainless steel with a circular cross-section. The support 37, the first protrusion 39 and the second protrusion 41 are arranged concentrically with respect to the longitudinal central axis C of the fluid burner head 9. The first protrusion 39 protrudes upward and outward from the outer edge of the support 37 while the second protrusion protrudes downward from the outer edge of the support 37 . The support 37, the first protrusion 39 and the second protrusion 41 are integrally formed with a structure designed to cooperate with the body 11 of the fluid burner head 9. More specifically, the support 37 is disposed and clamped between the tube 13 and the cap 15 by first and second protrusions 39, 41 protruding from the outer surface 43 of the body 11. (Figure 3). The first projection 39 has annular first and second longitudinal edges 39a, 39b extending along one another (Figure 6a). The first protrusion 39 is coupled to the body 11 indirectly along the first edge 39a, more specifically via the support 37, and the second edge 39b is free. The second projection 41 has annular longitudinal first and second edges 41a, 41b extending along one another (Figure 6b). The second protrusion 41 surrounds the main body 11, and its interior contacts the outer surface 43 of the main body 11 between the first and second edges 41a and 41b. The tube 13 and the cap 15 are connected by an element not shown in the drawing. Due to this, the support 37 and the first and second protrusions 39, 41 are located at the boundary 45 (FIG. 5) between the tube 13 and the cap 15, i.e. in the rows 29 of holes 27. extends around the longitudinal central axis C of the fluid burner head 9 above the uppermost row 29a (Figure 3). Also, with particular reference to FIGS. 5 and 6C, the support 37 has a first protrusion 39 that protrudes obliquely upward at an angle α = 30 degrees with respect to the longitudinal central axis C of the fluid burner head 9. And the second protrusion 41 is clamped between the tube 13 and the cap 15 so as to protrude downward from the outer surface 47 of the tube 13 and surround the uppermost portion of the tube 13.

The fluid burner head 9 is arranged to convey the boil-off gas to be burned into the combustion chamber 5 (Figure 1) of the fluid combustion unit 1. More specifically, referring to FIG. 4, the boil-off gas is supplied to the interior 49 of the tube 13 of the fluid burner head 9 via the lower end 19 of the tube 13, and then to the inside 49 of the tube 13 of the tube 13. upwardly through the lower part 21 and then into the upper part 23 of the tube 13 and further through the hole 27 in the tube wall 17 to the outside 51 of the tube 13 and thus into the combustion chamber. (5) (Figure 1) is supplied. Inside the combustion chamber 5, the boil-off gases are ignited and burn in a flame as described above. The first and second projections 39, 41 force the boil-off gas and the resulting combustion frame away from the body 11 of the fluid burner head even when the boil-off gas velocity and the boil-off gas pressure through the hole 27 are relatively low. The arrangement is such that the temperature is maintained sufficiently low to prevent melt damage to the tube 13 and crack damage to the cap 15. The truncated conical shape of the lower part 33 of the cap 15 accelerates the velocity of the evaporating gases through the hole 27 close to the upper end 25 of the tube 13, leading to a decrease in the temperature of the body 11 and, consequently, to the body ( 11) Arranged to assist in minimizing damage. The first and second protrusions 39, 41 will protect and shield the body 11 of the fluid burner head 9 and will be exposed to harsh environments. If the first and second protrusions 39, 41 are damaged, the device consisting of the support 37 and the first and second protrusions 39, 41 can be replaced with a new one, and the tube 13 and the cap ( 15) can be used further.

The above-described embodiments of the invention should be regarded as examples only. Those skilled in the art recognize that the embodiments discussed may be modified in various ways without departing from the spirit of the invention.

As an example, the fluid burner head need not include the second protrusion and may only include the first protrusion.

As another example, the fluid burner head need not include a support for fixing the first protrusion and possibly the second protrusion relative to the body of the fluid burner head. Instead, the first protrusion and possibly the second protrusion may be fixed directly to the body of the fluid burner head.

As another example, the support does not need to be fastened to the body of the fluid burner head by being clamped between the tube and the cap. In alternative embodiments of the invention, the support may be positioned to fit the outside of the tube and/or cap such that it is held in place by friction. Accordingly, the first and second protrusions do not need to be disposed at the boundary between the tube and the cap.

The first and second protrusions need not be formed separately from the tube and cap, but may be formed integrally with the tube and/or cap. This design may destroy the possibility of replacing only the first and second protrusions and the support, if present, if they are damaged.

The angle α between the first projection and the longitudinal central axis of the fluid burner head does not need to have the above value and can be larger or smaller.

The tube and cap need not be formed separately and made of different materials, but may instead be integrally formed and/or made of the same material.

It should be emphasized that descriptions of details not relevant to the invention have been omitted and that the drawings are only schematic and not drawn to scale. It can also be said that some parts of the drawing are simplified than other drawings. Accordingly, some components may be shown in one drawing but omitted in another drawing. Finally, as used herein, the prefixes “first,” “second,” etc. are used only to distinguish different elements and do not impose requirements regarding relative positioning or orientation.

Claims (15)

It is a fluid burner head 9 for a fluid combustion unit 1, and includes a body 11, wherein the body includes a hollow tube 13 for transferring the fluid to be burned into the combustion chamber 5 and an upper end of the tube 13 ( 25), the tube 13 further comprising a lower end 19 for receiving fluid within the tube 13, the wall 17 of the tube 13 comprises a plurality of rows 29 of holes 27, which rows 29 extend around the longitudinal central axis C of the fluid burner head 9, the holes 27 allowing the fluid to be burned to enter the tube. In the burner head (9), which allows the fluid to flow from the inside (49) to the outside (51) of (13),
Tubes 13 extend around the longitudinal central axis C of the fluid burner head 9 and obliquely from the outer surface 43 of the body 11 above the uppermost row 29a of holes 27 of the tubes 13. ) further comprising an annular first protrusion 39 projecting at an angle α with respect to the longitudinal central axis C of the fluid burner head 9 away from the lower end 19 of the 0 < α < 90 degrees. , Fluid burner head (9), characterized in that the uppermost row (29a) of holes (27) is the row of holes (27) arranged closest to the cap (15). The fluid burner head (9) according to claim 1, wherein the tube (13) and the cap (15) are formed separately. Fluid burner head (9) according to claim 1 or 2, wherein the cap (15) and the tube (13) are made of different materials. 4. The method according to any one of claims 1 to 3, wherein the first protrusion (39) protrudes from the outer surface (43) of the body (11) at the border (45) between the tube (13) and the cap (15). , fluid burner head (9). 5. Fluid burner head (9) according to any one of claims 1 to 4, wherein the tube (13) and the first projection (39) are formed separately. 6. The method according to any one of claims 1 to 5, wherein the upper part (23) of the tube (13) containing the hole (27) is substantially along the longitudinal central axis (C) of the fluid burner head (9). A fluid burner head (9) with a uniform cross section. 7. The method according to any one of claims 1 to 6, further comprising an annular support (37) extending around the longitudinal central axis (C) of the fluid burner head (9), the support (37) comprising the first A fluid burner head (9) connected to the protrusion (39) and engaged with the body (11) of the fluid burner head (9) to secure the first protrusion (39) to the body (11). 7. The method according to any one of claims 1 to 6, which extends around the longitudinal central axis (C) of the fluid burner head (9) and extends between the uppermost row (29a) of the holes (27) of the tubes (13) and the first The fluid burner head (9) further comprising an annular second protrusion (41) projecting from the outer surface (43) of the body (11) between the protrusions (39). 9. Fluid burner head (9) according to claim 8, wherein the second protrusion (41) protrudes from the outer surface (47) of the tube (13). 10. The method according to claim 8 or 9, further comprising an annular support (37) extending around the longitudinal central axis (C) of the fluid burner head (9), said support (37) comprising the first and second A fluid burner head (9) connected to the protrusions (39, 41) and engaged with the body (11) of the fluid burner head (9) to secure the first and second protrusions (39, 41) to the body (11). 11. Fluid burner head (9) according to claim 7 or 10, wherein the support (37) is clamped between the cap (15) and the tube (13). 12. Fluid burner according to any one of claims 1 to 11, wherein the cap (15) comprises an upper part (31) and a lower part (33), the lower part (33) protruding into the tube (13). Head (9). 13. Fluid burner head (9) according to claim 12, wherein the lower portion (33) comprises a portion that tapers in a direction away from the upper portion (31) of the cap (15). 14. Fluid burner head (9) according to claim 12 or 13, wherein the outer circumference of the upper part (31) of the cap (15) is larger than the inner circumference of the tube (13). Use of a fluid burner head (9) according to any one of claims 1 to 14 in a fluid combustion unit (1) for burning boil-off gases from a fuel tank on board a ship.