JP2006083992A - Mechanical seal cooler - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mechanical seal cooler for maintaining the effects of a sacrifice anode material for a long period while preventing the corrosion of a shell. <P>SOLUTION: The mechanical seal cooler comprises the shell 2 having a flow-in port 11 and a flow-out port 12 for cooling water, a cooling tube 3 provided in the shell 2 for the flow of high temperature fluid, a sacrifice anode rod 5 for preventing the electric corrosion of the shell 2 and the cooling tube 3, and a core material 6 via which the sacrifice anode rod 5 is arranged in the shell 2. The cooling tube 3 is formed of a metal having more electropositive potential than that of the shell 2, the core material 6 formed of a metal having the same potential as that of the shell 2 is mounted in the shell 2, and the sacrifice anode rod 5 is adhered and fitted to the core material 6, thus suppressing an increase in the contact resistance of a boundary portion 16 therebetween. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a cooler for a mechanical seal provided on a rotary shaft portion of a machine for chemical industry, a pump, or other various machines.

  Conventionally, when the liquid temperature of a flushing fluid used for a mechanical seal provided in a rotary shaft portion of a chemical industrial machine or the like is high, the flushing fluid is cooled using a cooler. The cooler used here is provided with a cooling tube inside a sealed shell (sealed cylinder), and a high-temperature flushing fluid is allowed to flow through the cooling tube and introduced into the shell outside the cooling tube. By filling the cooling water, heat exchange is performed between the high-temperature flushing fluid and the cooling water through the cooling tube, and the temperature of the flushing fluid is lowered to cool the mechanical seal.

  However, the cooling water currently used in petrochemical and refinery factories uses circulating water distributed in the factory by the cooling tower, so rust inhibitors and hard materials such as Si and Ca are used. In addition, since there is a large temperature difference between the inlet and outlet of the cooling tube of the cooler, a large amount of the hard material adheres to and accumulates on the outer peripheral surface of the cooling tube. As a result, the thermal efficiency of the cooler is reduced, and the high-temperature flushing fluid cannot be sufficiently cooled, resulting in a mechanical seal trouble. Therefore, as shown in FIG. 4, the hard material contained in the cooling water adheres to the cooling tube 30 and the shell 31 by coating the outer peripheral surface of the cooling tube 30 and the inner surface of the shell 31 with a fluororesin 32 having a predetermined thickness. The cooler 33 which prevented that is proposed (for example, refer patent document 1).

In addition, when it is difficult to secure industrial water due to geographical factors, seawater is used as cooling water, and in this case, a cooling tube made of stainless steel or the like may cause stress corrosion cracking. In order to prevent this, titanium is used as a constituent material of the cooling tube. However, when the above titanium made of a noble metal (cathode) with a high natural potential is used against a shell made of a base metal (anode) with a low natural potential in seawater, a titanium cooling tube and shell, etc. Due to the potential difference generated between the pipe member and the pipe member, corrosion of different metals (electric corrosion) occurs on the shell or the like. In order to prevent such corrosion, a cylindrical sacrificial anode rod 51 extending in the longitudinal direction of the shell 50 is disposed as shown in FIG. It is possible to fix to.
JP-A-8-135800

However, in the cooler 33 shown in FIG. 4, the corrosion of the shell 31 proceeds as seawater enters the gaps between the uncoated members and the damaged portions of the fluororesin 32 due to scratches during maintenance. There is a problem.
5A using the sacrificial anode rod, when the sacrificial anode rod 51 is thinned as shown in FIG. 5B, the sacrificial anode rod 51 and the mounting bolt 52 A gap S is formed between them, and impurities and the like in seawater are interposed in the gap, so that the contact resistance is increased and the effect as the sacrificial anode rod 51 cannot be sufficiently exerted. As a result, the shell 50 is corroded.
Therefore, in view of the problems of the prior art, the present invention provides a mechanical seal cooler that can prevent the corrosion of the shell (sealed cylinder) and maintain the effect of the sacrificial anode material over a long period of time. The purpose is to obtain.

In order to achieve the above object, the present invention takes the following technical means.
That is, the present invention provides a sealed cylinder having an inlet and an outlet of cooling water, a cooling tube provided inside the sealed cylinder and allowing a high-temperature fluid to flow, and the sealing cylinder and the cooling tube. A metal having a sacrificial anode material for preventing electrolytic corrosion and a core material for disposing the sacrificial anode material inside the sealed cylindrical body, wherein the cooling tube has a noble potential with respect to the sealed cylindrical body The core material is made of a metal having the same or base with respect to the sealed cylinder and a noble potential with respect to the sacrificial anode material, and the sacrificial anode material is infiltrated with the cooling water. It is characterized by being fixed in close contact with the core material to such an extent that it does not occur.

  According to the above-described mechanical seal cooler of the present invention, the sealed cylinder has a base potential with respect to the cooling tube, the core is the same or base with respect to the sealed cylinder, and the sacrificial anode material Therefore, the sacrificial anode material prevents the different metal contact corrosion (electric corrosion) of the cooling tube, the sealing cylinder, and the core material. Further, since the sacrificial anode material is closely fitted to the core material so that the cooling water does not enter between the core material, the cooling water is provided between the sacrificial anode material and the core material (boundary portion). Does not enter, and no foreign metal contact corrosion occurs at the boundary. Therefore, dissimilar metal contact corrosion occurs only from the boundary portion of the sacrificial anode material. From this, it is possible to maintain the effect of the sacrificial anode material over a long period (the lifetime of the sacrificial anode material) without causing an increase in contact resistance due to the formation of a gap between the sacrificial anode material and the core material. it can. Thereby, corrosion of a shell and a cooling tube can be prevented over a long period of time, and further, since the core material does not corrode, it is possible to prevent the sacrificial anode material from dropping off.

  Moreover, in the said invention, it is preferable that the said sacrificial anode material is arrange | positioned along the longitudinal direction of a sealing cylinder while exhibiting column shape. As described above, the sacrificial anode material is arranged along the longitudinal direction of the sealed cylindrical body, so that the effect of the sacrificial anode material on the sealed cylindrical body is enhanced, and the dissimilar metal contact corrosion of the sealed cylindrical body is effectively prevented. Can do.

  As described above, it is preferable that the length dimension of the sacrificial anode material arranged along the longitudinal direction of the sealed cylinder is ¼ or more of the length dimension of the sealed cylinder. For example, among the plate materials at both ends constituting the sealed cylinder, the plate material on one side to which the cooling tube is welded is made of the same metal as the cooling tube, and the sacrificial anode material is attached to the plate material on the other side, If the distance from the tip of the sacrificial anode material to the one side plate is long, there is a possibility that the different metal contact corrosion of the plate occurs. For this reason, the length of the sacrificial anode material is set to 1/4 or more of the length of the sealed cylinder, and the distance from the tip of the sacrificial anode material to the above plate is reduced, so that different metal contact corrosion of the plate is ensured. Can be prevented.

  In order to make the sacrificial anode material and the core material come into close contact with each other, it is preferable that the sacrificial anode material is integrally formed with the core material. This is because, for example, by integrally molding by injection molding or the like, the sacrificial anode material and the core material can be easily and reliably adhered.

  In the present invention, it is preferable that the sealing cylinder is provided with an attachment portion that does not penetrate outside the sealing cylinder, and the core member is attached to the sealing cylinder via the attachment portion. In this case, since the core member is attached via the attachment portion that does not penetrate to the outside of the sealed cylindrical body, it is possible to prevent the cooling water from leaking from the attachment portion.

  As described above, according to the present invention, since the increase in contact resistance between the sacrificial anode material and the core material is suppressed, the corrosion of the shell is prevented and the effect of the sacrificial anode material is maintained over a long period of time. be able to.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a mechanical seal cooler 1 according to a first embodiment of the present invention. This mechanical seal cooler (hereinafter referred to as “cooler”) is used to cool the temperature of a flushing fluid of a mechanical seal provided on a rotary shaft of a chemical industrial machine or the like. It is mainly constituted by a sealed cylinder (shell) 2 having an inlet 11 and an outlet 12, a cooling tube 3 for flowing a high-temperature fluid, and an anode member 4 provided inside the shell 2. The anode member 4 includes a sacrificial anode rod 5 (sacrificial anode material) and a core material 6.

  One end (right side in FIG. 1) of the shell is sealed by a circular side plate 8 fixed by a bolt and nut 7, and the other end (left side in FIG. 1) is fixed by a flange 10 fixed by a bolt and nut 9. It is sealed. An inflow port 11 is provided at the center of the circular side plate 8, and cooling water (seawater) flows from the inflow port 11 into the shell. In addition, an outlet 12 is provided in the vicinity of the other end of the outer periphery of the shell, and cooling water that has entered from the inlet 11 circulates inside the shell 2 and exits from the outlet 12. .

  The cooling tube 3 for flowing a high-temperature fluid has a diameter slightly smaller than the inner peripheral diameter of the shell 2 and is provided so as to circulate around the longitudinal direction of the shell 2 as an axial direction. Both ends of the cooling tube 3 are connected to a fluid inlet portion 13 and a fluid outlet portion 14 provided on the flange 10 by welding. Two set plates 15 having an L-shaped cross section are attached to the lower part of the shell with a required interval, and the cooler 1 is installed at a predetermined place by the set plates 15.

  The anode member 4 is composed of a sacrificial anode rod 5 for preventing dissimilar metal contact corrosion (electric corrosion) of other members (shell etc.) and a core material 6 for disposing the sacrificial anode rod 5 inside the shell 2. Yes. Among these, the sacrificial anode rod 5 is closely fitted (fixed) to the core material 6, and the core material 6 is attached to the circular side plate 8 in a state where the sacrificial anode rod 5 is skewed toward the flange 10 side. It is erected. That is, the sacrificial anode rod 5 and the core material 6 are arranged along the longitudinal direction of the shell 2, and this increases the effect of the sacrificial anode rod 5 on the shell 2, thereby preventing the dissimilar metal contact corrosion of the shell 2. It can be effectively prevented.

  The sacrificial anode rod 5 has a cylindrical shape with a required diameter through which the core member 6 penetrates in the inner peripheral portion, and is formed with a length about half the longitudinal dimension L of the shell 2. The sacrificial anode rod 5 is preferably configured such that its length dimension S is ¼ or more of the shell length dimension L, so that the dissimilar metal contact corrosion of the flange 10 is prevented. It can be surely prevented. The reason is that the distance f1 from the tip 5a of the sacrificial anode bar 5 to the flange 10 is shortened, so that the sacrificial anode bar 5 has a corrosion-inhibiting effect on the shell 2 even when the shell 2 is affected. This is in order not to lower the electrolytic corrosion prevention effect. If the distance f1 from the tip 5a of the sacrificial anode rod 5 to the flange 10 is long, the dissimilar metal contact corrosion of the shell 2 is prevented, but the dissimilar metal contact corrosion of the flange 10 may occur.

  The core member 6 has a cylindrical shape having the same diameter as the inner peripheral diameter of the sacrificial anode rod 5, and is disposed in a state of fitting to the inner peripheral portion of the sacrificial anode rod 5 and slightly projecting the tip portion 6 a. Yes. Further, the core material 6 is in close contact with the sacrificial anode rod 5 with no gap so that the cooling water does not enter at the outer peripheral portion (see FIG. 2A). Therefore, since the cooling water filled in the shell 2 does not intervene at the boundary portion 16 between the sacrificial anode rod 5 and the core material 6, the sacrificial anode rod 5 does not melt at the boundary portion 16. It is like that. In order to bring the sacrificial anode rod 5 and the core material 6 into close contact with each other without a gap, for example, the sacrificial anode material may be integrally formed around the core material 6 by injection molding. This is because the sacrificial anode rod 5 and the core material 6 can be easily and reliably brought into close contact if they are integrated by injection molding. Further, a margin may be provided between the inner peripheral portion of the sacrificial anode rod 5 and the outer peripheral portion of the core member 6, and these may be brought into close contact by an interference fit. In order to achieve an interference fit, the core material 6 may be press-fitted into the sacrificial anode rod 5 by pressing or the like, or a shrink fit may be used.

  Further, a screw portion 17 is formed at the base end portion 6b of the core member 6, and the screw portion 17 and a screw hole 18 (attachment portion) formed on the inner surface of the circular measuring plate 8 are screwed together. Thus, the core member 6 is attached to the circular side plate 8. The screw hole 18 is provided at a position slightly deviated from the radial center of the circular side plate 8 to the outside of the diameter, and the anode member 4 is arranged so as to deviate from the axis of the shell 2. Thereby, the sacrificial anode rod 5 becomes close to the cooling tube 3, and the electric corrosion prevention effect of the cooling tube 3 can be enhanced. Further, the screw hole 18 does not penetrate the outer surface of the circular side plate 8. Therefore, even if the fluid inside the shell 2 enters the threaded portion 19, the fluid does not leak out of the shell 2, and fluid leakage in the screw hole 18 (attachment portion) can be reliably prevented. Further, as shown in the enlarged view of FIG. 1, a nut 20 for preventing loosening is screwed into the screw portion 17 of the core member 6, and the core member 6 is tightened by a force by which the nut 20 is tightened to the circular side plate 8 side. Is prevented from loosening. Thereby, the core material 6 can be easily attached to the shell 2, the loosening of the core material 6 with respect to the shell 2 is prevented, and the reliability of the cooler 1 in long-term use can be ensured.

  Regarding the constituent materials of each member, the flange 10 and the cooling tube 3 are made of titanium which is a metal material (cathode) having a noble potential (natural potential) with respect to the shell 2, and the shell 2 and the circular side plate 8 are These are all made of stainless steel, which is a metal (anode) having a base potential with respect to the cooling tube 3. Further, the core member 6 of the anode member 4 is made of the same stainless steel as that of the shell 2, and the sacrificial anode rod 5 is made of aluminum having a base potential lower than that. The core material 6 may be any metal that is the same or base with respect to the shell 2 and is noble with respect to the sacrificial anode rod 5. The reason why titanium is used for the cooling tube 3 is to prevent stress corrosion cracking that occurs when stainless steel or the like is used by using titanium having a higher potential. The reason why titanium is used for the flange 10 is to securely connect the flange 10 and the cooling tube 3 by welding. The stainless steel is used for the shell 2 and the circular side plate 8 because of the cost, and the stainless steel is used for the core member 6 among the anode members 4 to avoid corrosion and to prevent the sacrificial anode rod 5 from being used. This is to support the shell 2 for a long time. In addition, the constituent material of each said member is not limited to the thing of this embodiment.

The cooler 1 of the present embodiment is installed in the flushing line when the temperature of the flushing fluid in the mechanical seal provided in the rotary shaft portion of various machines becomes high. Cooling water (for example, seawater) flows into the inside of the shell 2 from the inlet 11 of the circular side plate 8 and flows out of the outlet 12, while hot flushing fluid flows from the fluid inlet 13 of the flange 10 to the cooling tube 3. Inflow and heat exchange with the cooling water while circulating around the inside of the shell 2. By this heat exchange, the flushing fluid is cooled, discharged from the fluid outlet 14, and sent to the mechanical seal (not shown) side.

  According to the cooler 1 of the present embodiment, the shell 2 (sealed cylinder) is made of a metal having a base potential with respect to the cooling tube 3, and the core member 6 has the same potential with respect to the shell 2. The sacrificial anode 5 can prevent different metal contact corrosion of the cooling tube 3, the shell 2 and the core material 6. In addition, since the sacrificial anode rod 5 is closely fitted to the core material 6, fluid cannot enter the boundary portion 16 (joint portion) between the sacrificial anode rod 5 and the core material 6, and the boundary portion 16 Dissimilar metal contact corrosion does not occur. Accordingly, the dissimilar metal contact corrosion occurs only from the outer peripheral surface 5b and the end surface 5c of the sacrificial anode rod 5, as shown by the arrows in FIG. For this reason, there is no gap due to the dissolution of the sacrificial anode rod 5 at the boundary portion 16, and for example, impurities in seawater do not intervene. Since no impurities are present, the contact resistance between the sacrificial anode rod 5 and the core material 6 is not increased, the effect of the sacrificial anode rod 5 is not lowered, and the effect is maintained for a long time (sacrificial anode rod). 5 lifetimes). Thereby, the core material 6 is prevented from being corroded, the sacrificial anode rod 5 can be prevented from falling off due to the long-term use of the cooler 1, and the shell 2 and the cooling tube 3 can be prevented from corroding for a long time. it can.

  In addition, the said embodiment is an illustration and is not limited. For example, as shown in FIG. 3, in order to change the number of sacrificial anode rods 5, the anode members 4 composed of the sacrificial anode rods 5 and the core material 6 are equally spaced in the circumferential direction around the radial center of the circular side plate 8. You may make it provide three places. In addition, the shape of the sacrificial anode rod 5 may be changed to increase its surface area, thereby enhancing the effect of preventing electrolytic corrosion. Furthermore, although the sacrificial anode material has a cylindrical shape in the above embodiment, it may have a cross-sectional square shape or other various shapes.

It is sectional drawing of the cooler for mechanical seals which concerns on 1st Embodiment of this invention. (A) is radial direction sectional drawing of an anode member, (b) is a partial decision sectional drawing of the longitudinal direction of the anode member. It is arrangement | positioning explanatory drawing of the anode member which concerns on 2nd Embodiment. It is sectional drawing of the cooler in a prior art. (A) is sectional drawing of the cooler in another prior art, (b) is explanatory drawing which shows the state which the sacrificial anode material of the cooler melt | dissolved.

Explanation of symbols

1 Cooler for mechanical seal 2 Shell (sealed cylinder)
3 Cooling tube 4 Anode member 5 Sacrificial anode rod 6 Core material 16 Boundary portion 18 Screw hole 20 Nut (for loosening prevention)

Claims (5)

A sealed cylinder having an inlet and an outlet for cooling water, a cooling tube provided inside the sealed cylinder and allowing a high-temperature fluid to flow, and sacrifice for preventing electrolytic corrosion of the sealed cylinder and the cooling tube An anode material, and a core material for disposing the sacrificial anode material inside the sealed cylinder,
The cooling tube is made of a metal having a noble potential with respect to the sealed cylinder, and the core material is the same or base with respect to the sealed cylinder and is noble with respect to the sacrificial anode material. Made of a metal with potential,
The mechanical seal cooler, wherein the sacrificial anode material is fixed in close contact with the core material to such an extent that the cooling water does not enter.   The cooler for mechanical seals according to claim 1, wherein the sacrificial anode material has a columnar shape and is disposed along a longitudinal direction of the sealed cylindrical body.   The cooler for a mechanical seal according to claim 2, wherein a length dimension of the sacrificial anode material is ¼ or more of a length dimension of the sealed cylindrical body.   The cooler for mechanical seals according to any one of claims 1 to 3, wherein the sacrificial anode material is integrally formed with the core material.   The attachment part which does not penetrate to the exterior of the said sealing cylinder in the said sealing cylinder, and the said core material is attached to the said sealing cylinder via the said attachment part. Cooler for mechanical seal.

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