JP2016205462A - Nozzle for steam trap - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a nozzle type steam trap preventing foreign matters such as rust or dust in a piping system from getting clogged into a nozzle, even in a case of blocking foreign matters with a strainer including a screen.SOLUTION: Provided are: a nozzle of which a tip 13 is formed into such a shell-like shape as to become slenderer toward the forefront, and/or at the tip 13 of which a groove 16 is formed; and a steam trap using the nozzle. Further, provided are a nozzle of which the surface is subjected to water/oil repellent processing, and a steam trap using the nozzle.SELECTED DRAWING: Figure 4

Description

  In various factories and facilities that use steam as a heat source via a heat exchanger, the present invention provides drainage (condensate with condensed steam) generated in steam-using equipment and a steam transport piping system between these equipments. The present invention relates to a nozzle of a nozzle-type steam trap that can automatically and continuously be discharged out of the system and has a drain drainage adjustment mechanism.

  In various factories and facilities that use steam as a heat source via a heat exchanger, it is necessary to automatically discharge the drain generated in the steam-using equipment and the steam transport piping system between these equipments.

  This is to ensure proper temperature conditions in the steam transport piping that connects the steam using equipment such as the heat exchanger section of the dryer and heating kiln, and to ensure stable and safe operation of the factory. is there. For example, if drain stays in steam-using facilities or steam transport piping systems, the heating efficiency is reduced, and the productivity of the equipment is remarkably reduced, and heating unevenness due to drain droplets can cause poor product quality. This will interfere with the stable operation of the factory. In addition, the drain accumulated in the steam piping system creates a large lump while being swept away by steam, collides with the bent part of the piping and the valve, or condenses all at once when it comes into contact with the steam and the steam volume becomes zero. This can cause a steam hammer in which a drain is pushed and collides with a place where a vacuum is created locally. If this steam hammer occurs, the pressure and pressure in the pipe will suddenly change, leading to damage to the gaskets and flanges of the connection part, as well as the valve itself. There is sex.

  Therefore, a large amount of steam straps are installed in the factories and facilities, etc., and conventionally mechanical steam traps (bucket type / float type), thermostatic steam traps (bimetal type / bellows type), and Thermodynamic steam traps (disc type) have been used.

However, these mechanical steam traps have the following problems. The mechanical steam trap is a drain valve mechanism having a movable part. When a certain amount of drain is stored, the drain is opened by opening the drain valve, and then the drain valve is closed immediately thereafter. Therefore, due to this mechanism, moving parts are damaged due to operational delays and repeated operations, and a large amount of steam leakage cannot be avoided, and intermittent drainage of the mechanical steam trap guarantees stable operation of steam-using equipment. Not what you want. In particular, the problem of mechanical steam traps consuming a large amount of steam has tended to be overlooked by designers and boiler managers who have a strong awareness of the need for drainage.・ It has been reviewed from the viewpoint of global environmental conservation such as CO ₂ reduction.

  Under such circumstances, there is an increasing interest in various nozzle-type steam traps having a drainage amount adjusting mechanism such as an orifice nozzle type, a venturi nozzle type, and a tunnel structure resistance pipe type steam trap. These are called fluidic steam traps, which use a drainage mechanism in which water has a lower kinematic viscosity when passing through fine passages than steam and water flows about 30 times that of steam. The structure has no moving parts. Therefore, unlike the conventional steam trap having a movable part, continuous drainage with less steam leakage is realized, and the amount of fuel used in the boiler is greatly reduced. In addition, the structure without moving parts is excellent in durability and can be easily maintained and inspected. Furthermore, it is resistant to steam hammers and freezing, and has excellent stability and safety.

  For example, the venturi nozzle type steam trap shown in FIGS. 1 and 2 has a very simple structure, and the amount of drainage can be controlled by simply rotating the body 1 without replacing the nozzle, and if the nozzle is replaced. It is possible to control an extremely wide amount of drainage (Patent Document 1).

  However, there are also problems with the various nozzle-type steam straps. When the nozzle diameter through which the drain passes is small, foreign matter such as rust and dust in the pipe is likely to be clogged. Therefore, the screen screen used in a foreign matter removal device called a strainer that cleans the fluid itself must be made finer than usual. Don't be. For example, a screen finer than 100 mesh as described in Patent Document 2, Patent Document 3, Patent Document 4, and the like is necessary, but if the screen is smaller than 100 mesh, the rigidity of the screen is significantly reduced. For this reason, it is difficult to maintain the form of the screen, attach / detach and clean, and the screen must be reinforced (Patent Document 1).

  In addition, while a factory or facility is in operation, a strainer fitted with a screen of about 100 mesh can prevent clogging of nozzles due to foreign matter such as rust and dust in the piping, but the factory and facility are stopped. Then, there is a problem that fine foreign matter accumulates at the tip of the nozzle as it passes through the screen and clogs the nozzle hole. For example, in the case of an orifice-type steam trap, as in Patent Document 5, a device for eliminating a clogged orifice by providing a member capable of removing foreign matter blocking the orifice has been studied.

Japanese Patent No. 5694619 JP 2010-156450 A U.S. Pat. No. 4,745,943 US Pat. No. 5,120,336 JP 2008-309290 A

  As described above, the various nozzle-type steam traps currently used still have a problem that the nozzles are clogged with foreign matters such as rust and dust in the piping system. The present invention provides a nozzle that can easily remove foreign matter such as rust and dust in the piping system covering the nozzle hole, and a nozzle-type steam trap that is not clogged with foreign matter such as rust and dust in the piping system. The purpose is to provide. In particular, a nozzle suitable for a venturi nozzle type steam trap is provided, and a venturi nozzle type steam trap using the nozzle is provided.

  As a result of various studies to solve the problems of the prior art, the shape of the nozzle mounted on the various nozzle-type steam traps is devised, and the surface of the nozzle is processed to deposit on the nozzle to cover the hole. It has been found that foreign substances can be removed, and the present invention has been completed.

  There are two basic inventions regarding the shape of the nozzle. A first aspect of the present invention is to provide a nozzle characterized in that the tip has a shape like an elongated cannonball toward the forefront. 2nd invention is providing the nozzle characterized by the groove | channel being formed in the front-end | tip from the most advanced to the end.

  The invention relating to the surface treatment of the nozzle is to provide a nozzle characterized in that at least the tip portion is subjected to water / oil repellent treatment.

  As a result, it is possible to provide a nozzle type steam trap in which the nozzle of the shape and / or surface treatment is mounted.

  By adopting the shape of the present invention, the ball valve disposed at the tip of the strainer is opened to remove foreign matter such as rust and dust in the pipe and clean the strainer, and at the same time, foreign matter deposited at the tip of the nozzle Is also removed, and clogging of the nozzle can be eliminated. In addition, the water-repellent / oil-repellent treated nozzle not only provides the same effect as the shape but also improves the corrosiveness of the nozzle and improves durability. Further, by using both of these, foreign matters accumulated at the tip of the nozzle can be more easily removed, clogging of the nozzle can be eliminated, corrosion resistance is improved, and durability is improved. On the other hand, the screen attached to the strainer for cleaning the fluid can also be made to have a mesh of 100 mesh or more, so that it is possible to easily maintain the form of the screen, attach / detach, wash, and the like. As a result of the above, the convenience of the nozzle type steam trap, that is, the feature that it is excellent in durability and can be easily maintained and inspected becomes more remarkable.

It is the schematic diagram of the external appearance which removed the end cap, nozzle, and packing of the venturi nozzle type steam trap provided with the drainage amount adjustment mechanism. It is a schematic diagram which shows the cross section which cut | disconnected the venturi nozzle type steam trap provided with the drain waste_water | drain adjustment mechanism of FIG. 1 in parallel with the paper surface. It is a schematic diagram which shows the example of embodiment of the venturi nozzle (b) characterized by the shape of the conventional venturi nozzle (a) and the front-end | tip of this invention being a long and slender cannonball. It is a schematic diagram which shows the example of embodiment of the venturi nozzle characterized by having formed the groove | channel in the front-end | tip of this invention. It is a schematic diagram showing an example of an embodiment of a venturi nozzle characterized in that the tip of the present invention is bullet-shaped and a groove is formed.

  Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings using a venturi nozzle type steam trap as a representative example, but the present invention is not limited to these, and is described in the claims. All embodiments that fall within the scope of the technical idea are included.

  1 and 2 show an example of a venturi nozzle type steam trap equipped with the nozzle of the present invention. 1 and 2, a screen 6 with a support body having a drain drainage amount adjusting mechanism capable of controlling the height difference between the drain discharge port 9 and the drain outlet outside the drain system by the rotation of the body 1 and reinforcing the rigidity of the screen with a support body. Although a venturi-nozzle type steam trap having a nozzle is shown, any steam trap that uses a nozzle is not limited thereto (for example, Patent Document 1).

  FIG. 3 (a) shows a conventional venturi nozzle, and FIG. 3 (b) shows an embodiment of a venturi nozzle characterized in that the tip of the present invention is shaped like a long and slender bullet. Indicated. By making the tip of the venturi nozzle the shape of the present invention, when the ball valve 8 is opened, foreign matter such as rust and dust in the pipe is removed together with the drain, and the strainer is cleaned at the same time. Foreign matter such as rust and dust accumulated in the pipe is easily removed.

  A similar effect can be obtained by forming a groove at the tip of the conventional venturi nozzle shown in FIG. 3A as shown in FIG. This effect is because when the ball valve 8 is opened, the flow rate of the drain flowing through the groove is increased, and there is no particular limitation on the shape. However, it is preferable that the shape of the groove extends outward from the most advanced hole in order to remove foreign matter. This is because, as the flow velocity of the most advanced hole when the hole valve 8 is opened and the drain is discharged is faster, the foreign matter is more easily removed, and if the groove is widened, the foreign matter is more likely to flow out. Furthermore, it is more preferable to form a spiral groove as shown in FIG. The reason for this is not clear, but it is thought that a swirl flow is generated when drainage is released due to the spiral formation. Moreover, although there is no restriction | limiting also in the number of a groove | channel, from a viewpoint of foreign material removal, it is preferable that there are two or more.

  Furthermore, by combining the first invention according to the first invention with a shape like a long and slender cannonball toward the forefront, and the second invention according to which a groove is formed at the tip, The removal effect is increased. FIG. 5 (a) shows an embodiment thereof. Also in this case, the shape and number of the grooves are not limited, but it is preferable that there are two or more grooves formed in a spiral shape from the most distal end toward the end as shown in FIG. The reason is as described in paragraph 0021 above.

  In addition to such a shape, by adding water repellency and oil repellency to the nozzle surface, it is difficult for foreign matter to accumulate on the nozzle, and the deposited foreign matter can be easily removed. As a method for imparting water repellency and oil repellency, fluororesin coating (Teflon (registered trademark) processing) formed by nozzle pretreatment, fluororesin coating, firing, or silicon resin having an alkoxy group or silanol group A general surface treatment such as a silicone resin coating formed by heat curing or photocuring can be used. In addition, even in silicone resin coating, inorganic coating formed by polycondensation reaction between alkoxysilane and silicone resin having alkoxy group or silanol group is not only excellent in water and oil repellency, but also in chemical resistance, corrosion resistance, It is particularly preferable because of excellent mechanical properties such as hardness.

  Even if such surface treatment is applied before or after making a hole in the nozzle, there is no significant effect on the effect of removing foreign matter from the nozzle, but the surface treatment is performed after making a hole. Is more preferable. This is because water repellency and oil repellency are imparted also to the inside of the hole, preventing the accumulation of foreign matter and removing the deposited foreign matter easily.

  As described above, the present invention is particularly preferably a nozzle that has a bullet-shaped tip and two or more spiral grooves, and has been subjected to water / oil repellent treatment after the grooves and holes have been processed. The nozzle-type steam trap of the present invention is equipped with the nozzles having various shapes and water / oil repellency, and it is difficult for foreign matter such as rust and dust in the pipe to accumulate. However, it can be easily removed and maintenance and inspection can be performed easily.

  The reason why it is required to prevent foreign matter from accumulating on the nozzle and to prevent clogging due to the foreign matter deposited on the nozzle is based on the following various reasons.

  The nozzle is finely selected from a nozzle diameter of about 0.1 mm to 15 mm depending on the operating conditions and environmental conditions of the apparatus. Therefore, in order for the nozzle not to be clogged by rust, dust, etc. in the pipe, a screen having an opening smaller than the nozzle diameter is required, and the numerical value is 300 mesh (opening is about 0.045 mm). It is possible to cope with ˜2 mesh (aperture approximately 11 mm). However, when the nozzle diameter is reduced, for example, in the case of about 0.1 mm to 3 mm, even if foreign matter is removed with a screen of 300 mesh (opening about 0.045 mm) to 8 mesh (opening about 2.5 mm), Depending on the shape of the foreign material, it may pass through the screen. In addition, when the operation of the apparatus is stopped, foreign matters passing through the screen may accumulate on the nozzles, and the drain may not flow when restarting.

  As described above, the method of preventing clogging by foreign matter on the screen involves replacing the screen together with the replacement of the nozzle, which impairs the feature of the nozzle-type steam trap that is easy to maintain and inspect. Therefore, when the nozzle diameter is 0.1 mm to 3 mm, a screen of 100 mesh (aperture approximately 0.15 mm) to 80 mesh (aperture approximately 0.18 mm) is used. In this case, since a foreign substance larger than the nozzle diameter cannot be removed by a screen, a device that can easily remove clogging of the nozzle is required.

  On the other hand, when dealing with a screen exceeding 100 mesh (aperture approximately 0.18 mm), there is a problem that the clogging of the screen becomes severe and the replacement frequency increases. In addition, even if such a screen is metallic, its own rigidity is remarkably reduced. Therefore, a cylindrical screen reinforced with a support as shown in FIG. 2 is attached to a Y-type strainer to deform the screen. It is necessary to suppress and prevent deformation at the time of loading and unloading of the screen in the strainer maintenance due to clogging of the screen. In addition, when the operation of the foreign matter device with the screen is stopped, the foreign matter that passes through the screen may accumulate on the nozzles, and the drain may not flow when restarting.

1 Body 2 Packing 3 Venturi nozzle
4 End cap
5 Strainer
6 Screen with support
7 Strainer end cap
8 Ball valve 9 Venturi nozzle drain outlet 10 Drain reservoir 11 Drain outside outlet 12 Union 13 Nozzle tip 14 Nozzle end 15 Thread 16 Groove

Claims (7)

  In the nozzle-type steam trap, the tip of the nozzle has a shape of a bullet that is elongated toward the forefront.   In the nozzle-type steam trap, a nozzle is characterized in that a groove is formed at the tip of the nozzle from the most advanced nozzle hole toward the outer periphery of the nozzle.   The nozzle according to claim 2, wherein two or more spiral grooves are formed.   The nozzle according to claim 1, wherein the groove according to claim 3 is formed.   In the nozzle-type steam trap, at least the tip of the nozzle is subjected to water repellency / oil repellency treatment.   The nozzle according to any one of claims 1 to 4, wherein at least a tip of the nozzle is water- and oil-repellent.   A nozzle-type steam trap equipped with the nozzle according to any one of claims 1 to 6.

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