JP2017207156A - Angle valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an angle valve capable of effectively restricting wear of inside part of an angle valve where slurry flows.SOLUTION: An angle valve 1 of this invention comprises a valve main body 11 having a slurry flow inlet 11A opened in a horizontal direction and a slurry flow outlet 11B opened in a vertical direction and a plug 12 arranged to be slidable vertically within the valve main body 11 to control opening or closing of the slurry flow outlet 11B. Titanium nitride segments 30 are applied as paddings at liquid contact portions with the slurry at the inside part of the valve main body 11. The plug 12 is configured by a plug main body 21 and a plug stem 22 having the plug main body 21 connected at its extremity end, and the titanium nitride segments 30 are applied as welding of padding to at least an upper surface part 21t of the plug main body 21 and a liquid contact portion 13t with the slurry at a bonnet 13 for slidably guiding and holding the plug stem 22, for example.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an angle valve, and more particularly, to an angle valve used as a slurry control valve for adjusting the transfer of high-temperature and high-pressure acidic slurry, for example.

  In the refining of low-grade nickel ore using the High Pressure Acid Leach (hereinafter referred to as “HPAL”) method, nickel and cobalt are selectively selected from slurried ore (hereinafter referred to as “ore slurry”). In order to leach, the ore slurry is heated and stepped in steps and transferred to an autoclave.

  In the autoclave, sulfuric acid or the like is added and leaching is performed, and then the ore slurry is stepped down in temperature and transferred to the next step. The ore slurry after the leaching treatment contains many particles having high hardness that do not contain nickel.

  In the HPAL method, for example, in the temperature reduction / pressure reduction processing system 50 shown in FIG. 1, three pressure vessels (hereinafter referred to as “ores”) in which ore slurry pushed up by the internal pressure from the discharge pipe 51 of the autoclave is installed in series. , "Flash tank") 52 (52a, 52b, 52c) is a step of stepping down the temperature. In the temperature reduction and pressure reduction treatment process, the ore slurry that has passed through the flash tank 52 is finally cooled to a temperature of 100 ° C. or lower, and the pressure is reduced to atmospheric pressure.

  When stepping down the ore slurry step by step in the flash tank 52, the liquid level of the autoclave installed in the previous stage and the flash tank 52a are controlled by the control valve 53 (53a, 53b, 53c) installed in the upper part of each flash tank 52. The ore slurry is continuously extracted by controlling the liquid level of the ore to be constant. Since the ore slurry is transferred at a high temperature and a high speed due to a pressure difference between the flash tanks 52, the ore slurry has high wear properties. Moreover, since the ore slurry becomes acidic by the sulfuric acid added in the autoclave, it also has high corrosivity.

  As the control valve 53 at the upper part of the flash tank 52, an angle valve suitable for use of slurry, corrosive fluid, high-temperature high-pressure fluid or the like is used. Due to the structure of the control valve 53, a ceramic material having excellent wear resistance is generally used as the material of the plug main body and the seat part that progresses rapidly. On the other hand, it has excellent corrosion resistance for wetted parts where ceramic materials are difficult to use, such as the valve body (body), the plug stem that forms the shaft of the plug, and the bonnet that guides and holds the vertical sliding of the plug stem. Titanium material is used.

  However, due to the slurry flowing at a high temperature and at a high speed, the inside of the angle valve inevitably wears if continued to be used, and due to the wear, the slurry is ejected through the valve body. Things can happen. Since the progress of wear varies greatly depending on the operating state, it is necessary to periodically remove the angle valve, check the internal state of the valve, repair according to the wear state, and replace parts.

  Specifically, the wear inside the valve proceeds locally around the plug body and around the plug stem where the flow of slurry is disturbed, and conventionally, due to the wear of the plug insertion part of the bonnet and the wear of the root part of the plug stem, Plugs and bonnets are frequently replaced. Further, depending on the progress of wear of these portions, there is a possibility that slurry leakage to the outside due to a defective shaft seal portion may occur. And when replacing such valve parts, it is necessary to stop the equipment for a long time because of the temperature drop when the equipment is shut down and the temperature rise and pressure when the equipment is started. Therefore, it is desired to reduce the inspection cycle and the part replacement frequency.

  Here, in order to improve the wear resistance inside the angle valve, generally, a technique for forming a protective coating by glass lining or ceramic spraying has been proposed. For example, Patent Document 1 discloses an angle valve for slurry in which glass lining is applied to the inside of the valve to improve corrosion resistance and wear resistance. However, the glass lining inside the valve may be damaged due to temperature changes, and scales adhering to the piping and brick fragments lining the inner wall of the tank flow into the valve together with the slurry. The glass lining is easily broken by the collision and cannot exhibit sufficient wear resistance.

  Further, Patent Document 2 discloses a slurry control valve that prevents peeling by providing a structure that does not expose a deposited end portion of a protective coating in a slurry control valve that is sprayed with ceramic and coated with a protective coating. Yes. However, even when this method is made possible, the ceramic protective film is easily broken by the collision of the scale and the brick as in the case of the glass lining.

  As described above, the conventional technology cannot sufficiently suppress the wear inside the valve.

Japanese Patent Laid-Open No. 5-118448 JP-A-6-159528

  This invention is proposed in view of such a situation, and it aims at providing the angle valve which can suppress the abrasion inside the angle valve through which a slurry flows effectively.

  This inventor repeated earnest examination in order to solve the subject mentioned above. As a result, in an angle valve provided with a valve body and a plug that is slidable up and down inside the valve body and controls the outflow of the slurry, the wetted part with the slurry inside the valve body Furthermore, it has been found that local wear inside the valve can be effectively suppressed by overlay welding with titanium nitride, and the present invention has been completed.

  (1) The first invention of the present invention is a valve body having a slurry inlet opening in the horizontal direction and a slurry outlet opening in the vertical direction, and is slidable up and down inside the valve body. It is an angle valve provided with a plug that is disposed and controls opening and closing of the slurry outlet, and is an angle valve in which titanium nitride is overlay welded to a liquid contact portion with the slurry inside the valve body. .

  (2) According to a second aspect of the present invention, in the first aspect, the plug is composed of a plug body and a plug stem having the plug body connected to a tip, and at least the upper surface of the plug body. This is an angle valve in which titanium nitride is build-up welded to a portion and a wetted portion of a slurry in a bonnet that slidably guides and holds the plug stem.

  (3) According to a third aspect of the present invention, in the second aspect, a sealing material is provided between the plug stem and the bonnet, and the plug body is connected to the plug stem. This is an angle valve in which titanium nitride is overlay welded only at the root portion.

  (4) A fourth invention of the present invention is an angle valve according to any one of the first to third inventions, wherein the titanium nitride is overlay welded with a thickness of 0.5 mm to 2.5 mm. .

  (5) A fifth invention of the present invention is an angle valve according to any one of the first to fourth inventions, wherein the slurry is a high-temperature high-pressure acidic slurry obtained by high-pressure acid leaching.

  (6) According to a sixth aspect of the present invention, in any one of the first to fifth aspects, the liquid contact portion inside the valve body is made of a metal material having corrosion resistance and heat resistance. It is an angle valve.

  According to the angle valve of the present invention, local wear inside the angle valve through which slurry flows can be effectively suppressed. As a result, troubles of the angle valve due to wear can be prevented, costs for repairing and the like can be reduced, and operational efficiency can be increased.

It is a figure which shows an example of a structure of the processing system of temperature fall and pressure | voltage reduction provided with a flash tank and the control valve (angle valve) installed in the upper part of the flash tank. It is sectional drawing which shows the structure of an angle valve. It is an expanded sectional view in the specific part of the angle valve shown in FIG. 2, and is a figure for demonstrating the mode of the surface treatment process in the liquid-contact part inside a valve main body.

  Hereinafter, a specific embodiment of the present invention (hereinafter referred to as “the present embodiment”) will be described in detail with reference to the drawings. In addition, this invention is not limited to the following embodiment, A various change is possible in the range which does not change the summary of this invention.

<< 1. Angle valve configuration >>
The angle valve according to the present embodiment is an adjustment valve that is installed in an upper portion of a flash tank as shown in FIG. 1, for example, and controls the transfer of slurry between the flash tanks.

  The slurry is not particularly limited. For example, a slurry of nickel oxide ore used in the HPAL process, which is an acidic slurry in a high temperature state obtained by leaching with sulfuric acid under high temperature and high pressure. it can. As described above, in the HPAL process, the slurry in a high-temperature and high-pressure state is stepped down in temperature step by step using a plurality of flash tanks, but when transferring between flash tanks, due to the pressure difference, Slurry flows at high speed.

  The slurry is not limited to the ore slurry described above, and any type of slurry can be applied. Further, the angle valve according to the present embodiment can be effectively applied as, for example, a control valve for controlling the transfer of corrosive fluid, high-temperature and high-pressure fluid other than the above-described slurry, and here, These fluids are also included in the meaning of the term “slurry”.

  FIG. 2 is a cross-sectional view showing the configuration of the angle valve. As shown in FIG. 2, the angle valve 1 includes a valve main body 11 and a plug 12 disposed so as to be slidable up and down inside the valve main body 11. The valve body 11 has a slurry inlet 11A that opens in the horizontal direction and a slurry outlet 11B that opens in the vertical direction, and the slurry flowing in from the slurry inlet 11A flows through the valve body 11; It flows out through the slurry outlet 11B.

  Further, the plug 12 moves up and down (arrow X in FIG. 2) inside the valve body 11 to control the opening and closing of the slurry outlet 11B of the valve body 11. 2 shows a state where the slurry outlet 11B is closed by the plug 12. FIG.

  The angle valve 1 is characterized in that the surface of the valve body 1 in contact with the slurry is subjected to a surface treatment with titanium nitride. Here, the “wetted part” in the valve body 1 refers to a part where the slurry flowing at high speed in the valve body 1 is brought into contact with the valve body 1 based on the pressure difference, and is particularly composed of a material such as a ceramic having wear resistance. The part which is not.

[Valve body]
The valve body 11 constitutes the body of the angle valve 1, and the slurry flows through the inside thereof. As described above, the valve body 11 is provided with the slurry inlet 11A opened in the horizontal direction and the slurry outlet 11B opened in the vertical direction, and the slurry flowing in from the slurry inlet 11A It flows through the inside at high speed and flows out from the slurry outlet 11B.

  In the valve body 11, at least the liquid contact portion with the slurry in the inside thereof is made of a metal material that can be welded with a predetermined metal. In addition, the metal material preferably has corrosion resistance and heat resistance. For example, when transferring a high temperature and acidic slurry obtained by leaching with sulfuric acid by the HPAL process, the liquid contact part inside the valve body 11 is a metal material having corrosion resistance and heat resistance. Etc., it is possible to prevent deterioration or wear due to corrosion or heat. Moreover, by using such a metal material, it becomes possible to efficiently perform surface treatment processing by overlay welding of titanium nitride as will be described later.

  In the valve body 11, the slurry outlet 11 </ b> B is controlled to be opened and closed by a plug 12 described later. Specifically, when the plug 12 moves up and down, the plug main body 21 comes into contact with the opening of the slurry outlet 11B, and the plug main body 21 comes into a closed state. When the plug main body 21 leaves the opening of the slurry outlet 11B, the plug 12 opens. It becomes a state.

  In the slurry outlet 11B of the valve main body 11, since the opening / closing control by contact or non-contact of the plug 12 (plug main body 21) is performed in this way, the inner wall of the opening of the slurry outlet 11B has For example, a sheet member 11s made of a ceramic material or the like is provided to improve wear resistance. Further, by providing the sheet member 11s on the inner wall of the opening in this way, it is possible to suppress wear due to the slurry flowing out at high speed.

  The slurry outlet 11B is connected to a connection pipe 40 for transferring the slurry to a subsequent flash tank or the like. A sheet member 40 s made of a ceramic material or the like can also be provided on the inner wall of the connection pipe 40.

[plug]
The plug 12 moves up and down inside the valve body 11 (arrow X in FIG. 2), thereby controlling the outflow (transfer) of the slurry via the slurry outlet 11B. The plug 12 includes a plug main body 21 and a plug stem 22 that connects the plug main body 21 to the tip thereof.

(Plug body)
The plug body 21 has, for example, an inverted mountain shape having a taper or an inverted cone shape. The plug main body 21 comes into contact with the opening of the slurry outlet 11B of the valve main body 11 described above to close the opening, thereby stopping the outflow of the slurry. The plug body 21 is made of, for example, a material such as ceramic, or the surface of the metal material is coated with a ceramic or the like to enhance its wear resistance.

(Plug stem)
The plug stem 22 has a rod-like shape and constitutes the shaft of the plug 12. The plug body 21 is connected to the tip of the plug stem 22, and the plug body 21 is moved up and down by sliding upward or downward. The plug stem 22 is surrounded by a bonnet 13 inside the valve body 11, and can slide up and down by being guided and held by the bonnet 13.

  Here, between the plug stem 22 and the bonnet 13 that slidably guides and holds the plug stem 22, a seal member (shaft seal member) 13s for preventing the slurry from being ejected from the gap is provided on the circumference. Is provided. The shaft seal member 13s can be formed of, for example, packing, and can improve the sealing performance between the plug stem 22 and the bonnet 13 while preventing the plug stem 22 from sliding. Is not particularly limited. For example, an organic material such as rubber, an inorganic material such as ceramic, or the like, which has heat resistance, is particularly preferable.

≪2. Surface treatment in wetted parts >>
As described above, the angle valve 1 according to the present embodiment is characterized in that the surface of the valve body 11 in contact with the slurry is subjected to surface treatment with titanium nitride. Specifically, titanium nitride is overlay welded to a predetermined liquid contact portion inside the valve body 11.

  FIG. 3 is an enlarged cross-sectional view of a specific portion of the angle valve 1 shown in FIG. 2, and is a view for explaining a state of surface treatment processing in a liquid contact portion inside the valve body 11. As shown in FIG. 3, in the angle valve 1, titanium nitride 30 is overlay welded to a liquid contact portion with the slurry inside the valve body 11. Titanium nitride is a material having excellent wear resistance and corrosion resistance and heat resistance. In the wetted part with the slurry, by applying surface treatment processing for overlay welding of titanium nitride, the inside of the valve body 11 flows at a high speed and effectively suppresses wear due to the slurry having high temperature and strong acidity. Can do.

  For example, as shown in FIG. 3, the wetted part to be subjected to the surface treatment is wetted with at least the upper surface part 21t of the plug main body 21 and the slurry in the bonnet 13 that slidably guides and holds the plug stem 22. The portion 13t is preferable. Note that the upper surface of the plug body 21 refers to the surface to which the plug stem 22 is connected. The upper surface portion 21t of the plug body 21 and the liquid contact portion 13t with the slurry in the bonnet 13 are places where contact with the slurry flowing at high speed is high and the flow of the slurry is disturbed, and the slurry is likely to be worn. . In addition, these locations are locations where the plug 12 collides with each other as the plug 12 moves up and down, and not only wear due to the slurry but also deterioration wear due to mutual contact is likely to occur. Therefore, the wear inside the valve body 11 can be more effectively suppressed by forming the titanium nitride 30 by overlay welding at such a location.

  Further, as shown in FIG. 3, not only the upper surface of the plug body 21 but also the root portion 22 r of the plug stem 22, that is, the root portion to which the plug body 21 is connected in the plug stem 22 is surface-treated by overlay welding. The titanium nitride 30 can be formed by processing.

  Here, the plug stem 22 is guided and held by the bonnet 13 and slides up and down. Since the plug stem 22 also contacts with the slurry flowing inside the valve body 11, the plug stem 22 extends over almost the entire surface of the plug stem 22. It may be desirable to perform surface treatment. However, it is necessary to ensure sealing performance between the plug stem 22 and the bonnet 13 from the viewpoint of preventing the slurry from being ejected, and a shaft seal member 13s is provided in the gap. Therefore, when titanium nitride is welded over almost the entire surface of the plug stem 22, the build-up welded titanium nitride may damage the shaft seal member 13 s as it slides up and down. Therefore, in the plug stem 22, wear of the plug stem 22 can be effectively suppressed and the shaft seal can be effectively reduced by setting the titanium nitride to be welded over only the root portion 22r to which the plug body 21 is connected. It is possible to prevent the member 13s from being damaged, and to effectively prevent the slurry from being ejected.

  When titanium nitride is formed on the root portion 22r of the plug stem 22 by overlay welding, the titanium nitride formation height (titanium nitride formation height in the axial direction of the plug stem 22) is not particularly limited. The height is equivalent to a length of about 15% to 25% of the diameter of the plug body 21. The specific numerical value of the length depends on the size of the angle valve 1 and cannot be defined unconditionally, but can be about 0.5 mm to 50 mm in height.

  The thickness (formation thickness) of the titanium nitride 30 formed by the surface treatment process of overlay welding is not particularly limited and is preferably adjusted as appropriate according to the size of the angle valve 1. It is preferably about 2.5 mm, and more preferably about 1.0 mm to 2.0 mm. If the thickness of the titanium nitride 30 is less than 0.5 mm, sufficient wear resistance may not be exhibited, and the replacement frequency of components cannot be effectively reduced. On the other hand, if the thickness exceeds 2.5 mm, the cost increases and the slurry flow path inside the valve body 11 may be narrowed.

  As described above in detail, in the present embodiment, the valve main body 11 and the plug 12 that is disposed inside the valve main body 11 so as to be slidable up and down and controls the opening and closing of the slurry outlet 11B. In the provided angle valve 1, titanium nitride 30 is welded to the wetted part with the slurry inside the valve body 11. According to such an angle valve 1, it is possible to effectively suppress wear due to high-temperature slurry flowing at high speed. As a result, troubles in the angle valve 1 due to wear can be prevented, costs for repairing and the like can be reduced, and operational efficiency can be increased.

  In the present embodiment, the aspect in which the titanium nitride 30 is overlay welded to the liquid contact portion with the slurry inside the valve body 11 has been described. However, instead of titanium nitride, for example, tungsten carbide (WC) In the same manner, even if the alloy material is welded and welded, the wear due to the slurry can be effectively suppressed.

1 Angle valve 11 Valve body 12 Plug 13 Bonnet 21 Plug body 22 Plug stem 30 Titanium nitride

Claims (6)

A valve body having a slurry inlet opening in the horizontal direction and a slurry outlet opening in the vertical direction, and a plug that is slidably moved up and down inside the valve body and controls opening and closing of the slurry outlet. An angle valve with
An angle valve in which titanium nitride is overlay welded to a liquid contact portion with the slurry inside the valve body. The plug is composed of a plug body and a plug stem connected to the tip of the plug body,
2. The angle valve according to claim 1, wherein titanium nitride is build-up welded to at least an upper surface portion of the plug body and a liquid contact portion of a slurry in a bonnet that slidably guides and holds the plug stem. A sealing material is provided between the plug stem and the bonnet,
The angle valve according to claim 2, wherein in the plug stem, titanium nitride is overlay welded only at a root portion to which the plug body is connected. The angle valve according to any one of claims 1 to 3, wherein the titanium nitride is overlay welded with a thickness of 0.5 mm to 2.5 mm. The angle valve according to any one of claims 1 to 4, wherein the slurry is a high-temperature and high-pressure acidic slurry obtained by high-pressure acid leaching. The angle valve according to any one of claims 1 to 5, wherein the liquid contact portion inside the valve body is made of a metal material having corrosion resistance and heat resistance.

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