JP2000258071A - Cooling jacket structure for lance or burner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent corrosion due to strong acid produced through dew formation without sacrifice of cooling performance or cooling effect by coating the outer surface of a cooling jacket exposed to outer atmosphere with a corrosion- resistant and acid-resistant material. SOLUTION: The forward end face 14a and the outer surface 14b at of a cooling jacket 14, except the part of an oxidizing agent supply nozzle 13a at the forward end of a lance 11, is coated 18 with a corrosion-resistant and acid- resistant material. The coating material must exhibit corrosion resistance against corrosive substances being generated in the environment of using the lance 11 without blocking permeation of a solution containing the corrosive substances and must exhibit good adhesion to the material forming the cooling jacket 14. A corrosion-resistant metal, e.g. nickel, or a fluororesin is preferably employed as the coating material. Height of the coating 18 is preferably set in the range of 50-1000 μm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling jacket structure for a lance or a burner, and more particularly to a lance for blowing an oxidant into a furnace or a burner for burning fuel with the oxidant from a high-temperature atmosphere. It relates to the structure of a cooling jacket.

[0002]

2. Description of the Related Art In a lance for blowing an oxidizing agent and a burner for forming a flame used in an industrial furnace, in order to protect the lance and the burner from a high temperature atmosphere in the furnace, Cooling jackets are provided on these outer peripheries to circulate the refrigerant and to forcibly cool it. Normally, the cooling jacket is formed of a steel-based material, and water is used as a circulating refrigerant.

However, when water is circulated and cooled in the cooling jacket as described above, the temperature of the outer surface of the cooling jacket becomes 100 ° C. or less, and water vapor in the furnace atmosphere may condense on the outer surface of the cooling jacket. When dew condensation occurs, nitrogen oxides, sulfur oxides, chlorine, etc. in the furnace atmosphere dissolve into the dew condensation water and generate strong acids on the outer surface of the cooling jacket, corroding the metal that forms the cooling jacket, and causing The flowing water may leak.

On the other hand, if the outer surface of the cooling jacket is to be kept at 100 ° C. or higher in order to prevent dew condensation, the water inside will boil and generate steam, and the cooling efficiency will be significantly reduced.
There was a problem that sufficient cooling could not be performed.

[0005] Further, materials having excellent corrosion resistance and acid resistance generally have low thermal conductivity, so that the heat conduction required for a cooling jacket cannot be obtained, and the cooling capacity may be insufficient.
Further, there is a disadvantage that the cooling jacket itself becomes expensive.

Accordingly, an object of the present invention is to provide a cooling jacket structure capable of preventing corrosion by a strong acid generated by dew condensation without lowering the cooling capacity and cooling efficiency.

[0007]

In order to achieve the above object, a cooling jacket structure according to the present invention comprises a lance having an oxidant passage therein or a burner having a fuel and oxidant passage therein. In the cooling jacket provided, a coating made of a material having corrosion resistance and acid resistance is applied to an outer surface of the cooling jacket exposed to an external atmosphere, and the coating is formed at a tip of the cooling jacket at a lance. The surface is provided on the outer surface of the cooling jacket including the surface, and the burner is provided on the side surface of the cooling jacket excluding the front end surface of the cooling jacket. Further, it is characterized in that the material having corrosion resistance and acid resistance is a fluororesin or a corrosion-resistant metal.

[0008]

1 and 2 show an embodiment in which a cooling jacket structure according to the present invention is applied to a lance. FIG. 1 is a sectional view, and FIG. 2 is a front view as viewed from the lance tip side. It is.

The lance 11 has an oxidant supply pipe 13 forming an oxidant supply passage 12 and a cooling jacket 14 provided concentrically around the outer periphery of the oxidant supply pipe 13. , Double tube 1 with closed end
The refrigerant circulation path 17 is formed by inserting a partition pipe 16 into the inside of the pipe 5.

The leading end surface 14 of the cooling jacket 14 excluding the oxidizing agent supply nozzle 13a at the leading end of the lance 11
The coating 18 made of a material having corrosion resistance and acid resistance is applied to the a and the outer peripheral surface 14b. The coating material has corrosion resistance to corrosive substances expected to occur in an environment where the lance 11 is used,
In addition, it is necessary to select a material that does not allow a solution containing a corrosive substance to permeate and that has good adhesion to the material forming the cooling jacket 14. For example, a corrosion-resistant metal such as nickel or a fluorine-based material may be used. Resins are preferred.

The thickness of the coating 18 may be any thickness as long as the desired corrosion resistance and acid resistance can be obtained, and it is usually 50 μm to 1000 μm. If the coating 18 is too thick, cooling by the cooling jacket 14 will be insufficient, and the outer surface of the coating 18 may become hot. When a fluororesin is used, it is preferable to select one having a melting point of 200 to 300 ° C. or higher. The coating operation on the outer surface of the cooling jacket 14 can be performed by a usual method according to the coating material, for example, electrolytic plating or spraying.

As described above, by providing the coating 18 having corrosion resistance and acid resistance on the entire outer surface of the cooling jacket 14, even if a strongly acidic substance is generated on the outer surface due to dew condensation, the cooling jacket 14 is not corroded. Therefore, the lance 11 can be used for a long time. Further, the cooling capacity and cooling efficiency of the cooling jacket 14 are not impaired.

FIGS. 3 and 4 show an embodiment in which the cooling jacket structure of the present invention is applied to a burner.
Is a cross-sectional view, and FIG. 4 is a front view as seen from the burner tip side.

The burner 21 has a fuel supply pipe 23 forming a fuel supply path 22 and a cooling jacket 24 provided concentrically around the fuel supply pipe 23.
An oxidant supply passage 25 is formed between the fuel supply pipe 23 and the cooling jacket 24. Note that the nozzle 23a is
Around the fuel outlet 22a communicating with the fuel supply passage 22,
A plurality of oxidizing agent outlets 25 a communicating with the oxidizing agent supply passage 25 are provided. As described above, the cooling jacket 24 forms a refrigerant circulation path 28 by inserting a partition pipe 27 into a double pipe 26 whose tip is closed.

In such a burner 21, a material having the same corrosion resistance and acid resistance as described above is provided on the outer peripheral surface (side surface) 14b of the cooling jacket 24 except for the nozzle 23a at the tip of the burner and the distal end surface 24a of the cooling jacket 24. Is applied.

That is, the tip surface of the burner 21 becomes hot due to the contact with the flame generated from the burner 21.
Separation due to thermal expansion in metal-based coating materials and melting in resin-based coating materials may occur, and dew condensation hardly occurs.
It is preferable that the burner tip surface is not coated.

An experiment was conducted to confirm the effect of the coating by operating the burner coated as described above and a conventional non-coated burner under the same conditions. The cooling jacket is made of stainless steel, and the coating is made of 100 μm fluororesin.
The thickness was applied. The burner was set in a waste treatment furnace, and the flame temperature was set at 2400 ° C.

As a result, in the conventional burner, about 240
While the cooling jacket corroded during continuous operation for a long period of time and refrigerant leaked, the coated burner did not peel off the coating material even after continuous operation for 240 hours or more, and the cooling jacket also corroded. I couldn't see it.

It should be noted that the cooling jacket structure of the present invention can be applied to lances or burners having various structures generally used, and is not limited to the lances or burners having the structures shown in the above embodiments. .

[0020]

As described above, according to the cooling jacket structure of the present invention, the cooling jacket provided for protecting the lance and the burner can be prevented from being corroded by corrosive substances. Moreover, the cooling capacity and cooling efficiency of the cooling jacket are not reduced.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing one embodiment in which a cooling jacket structure of the present invention is applied to a lance.

FIG. 2 is a front view as viewed from a lance tip side.

FIG. 3 is a cross-sectional view showing one embodiment in which the cooling jacket structure of the present invention is applied to a burner.

FIG. 4 is a front view as seen from the tip side of the burner.

[Explanation of symbols]

11 lance, 12 oxidant supply path, 13 oxidant supply pipe, 13a oxidant supply nozzle, 14 cooling jacket, 14a tip end face, 14b outer peripheral face, 15 double pipe,
DESCRIPTION OF SYMBOLS 16 ... Partition pipe, 17 ... Refrigerant circulation path, 18 ... Coating, 21 ... Burner, 22 ... Fuel supply path, 22a ... Fuel ejection port, 23 ... Fuel supply pipe, 23a ... Nozzle, 24 ... Cooling jacket, 25 ... Oxidant Supply channel, 25a ... Oxidizing agent ejection port, 26: Double pipe, 27 ... Partition pipe, 28 ... Refrigerant circulation path, 29 ... Coating

Claims (3)

[Claims] 1. A cooling jacket provided on an outer periphery of a lance having an oxidant passage therein or a burner having a fuel and oxidant passage therein. A cooling jacket structure having a coating made of a material having acid resistance. 2. The coating is applied to the outer surface of the cooling jacket including the leading end surface of the cooling jacket in the lance, and is applied to the side surface of the cooling jacket excluding the leading end surface of the cooling jacket in the burner. The cooling jacket structure according to claim 1. 3. The cooling jacket structure according to claim 1, wherein the material having corrosion resistance and acid resistance is a fluororesin or a corrosion-resistant metal.