Description

WATER SUPPLING VALVE HAVING FUNCTION FOR PREVENTING BACKWARD FLOW

Technical Field

[1] The present invention relates to a water supply valve having a function for preventing a backward flow, and more particularly to a water supply valve having a backflow prevention function, in which backpressure is generated by a water hammer occurring when the valve is rapidly opened and closed or when pressure in an apparatus such as a boiler, in which circulating water is supplied, is higher than the water pressure therein, thereby preventing a backflow of water in a circulation pipe. Background Art

[2] In systems such as thermal power plants and boilers in which cooling water or circulating water is supplied, generally, circulating water is supplied and interrupted by opening and closing of a water supply valve in order to increase heat-exchange.

[3] A conventional water supply valve for circulating water as described above is shown as an example in FIG. 1.

[4] In FIG. 1, reference numerals 1, 2, 4, 5, 6, and 7 denote an opening, a valve body, an inlet hole, an outlet hole, a bellows plate, and an inlet pipe, respectively. Further, reference numerals 8, 9, 10, 11, 12, and 13 indicate an outlet pipe, an upper cover, a solenoid, a rubber rod, a plunger, and a spring, respectively.

[5] As shown in FIG. 1, the conventional water supply valve for circulating water includes the valve body 2 with the opening formed at an upper portion thereof, the bellows plate 6 mounted to cover the opening 1 and having the inlet hole 4 an the outlet hole 5 formed therein, the inlet pipe 7 connected to a side of the valve body 2, the outlet pipe 8 extending through the other side of the valve body 2 and connected to the outlet hole 5 of the bellows plate 6, the upper cover 9 located over the bellows plate 6, and the plunger 12 suspended elastically to the upper cover 9 by the spring 13, having the rubber rod 11 attached to a lower end thereof, and moving downward by the solenoid 10 to open and close the outlet hole 5 of the bellows plate 6.

[6] In the water supply valve for the circulating water, when the supply of electricity is interrupted, the spring 13 enables the rubber rod 11 attached to the lower end of the plunger 12 to close the outlet hole 5. Therefore, pressure by the plunger is identical with pressure by the inlet pipe, so that fluid flows toward the outlet pipe even though the fluid is supplied through the inlet hole.

[7] However, when electricity is applied to the solenoid valve, the plunger moves upward so that the fluid can flow through the output hole of the bellows plate.

[8] At this time, since the pressure caused by the plunger is lowered, the bellows plate expands upward to allow the fluid to flow from the inlet pipe to the output pipe.

[9] The fluid flow can be controlled by using pressure difference and solenoid valve generating small force.

[10] If the pressure of the outlet pipe is higher than that of the inlet pipe for some reason, the bellows plate is facilitated to expand upward so as to cause the fluid to flow back. Disclosure of Invention Technical Problem

[11] Accordingly, the present invention has been made to solve the above-mentioned problems occurring in the prior art, and it is an object of the present invention to provide a water supply valve having a backflow prevention function, in which backpressure is generated by water hammer occurring when the valve is rapidly open and closed or when pressure in an apparatus such as a boiler in which circulating water is supplied is higher than water pressure, thereby preventing a backflow of water in a circulation pipe. Technical Solution

[12] In order to accomplish the object of the present invention, there is provided a water supply valve having a backflow prevention function, which includes: a pipe assembly forming a fluid chamber with an upper portion opened, and having an inlet pipe which extends through a side of the fluid chamber and is bent upward, and an outlet pipe connected to the other side of the fluid chamber; a bellows mounted on the upper portion of the fluid chamber of the pipe assembly and formed with an outlet hole at a portion of the bellows, for opening and closing an opening of the inlet pipe; and a cover movably coupled to the fluid chamber to cover the bellows, and having a spring recess in which a buffer spring is inserted so as to compress the bellows.

[13] The inlet pipe of the pipe assembly has one end with a rectangular shape. A second fluid chamber is formed at the end of the inlet pipe. A water inlet pipe is formed at a side of the second fluid chamber which has an opening formed at an upper portion of the second fluid chamber. A bellows plate is mounted over the opening and formed with a water inlet hole and water outlet hole so that the water outlet hole is communicated with an end of the inlet pipe. An upper cover is coupled to the second fluid chamber to cover the bellows plate, and a plunger is suspended by a spring to the upper cover and has a rubber rod attached to a lower end of the plunger, which is raised and lowered by a solenoid so as to open and close the water outlet hole of the bellows plate.

Advantageous Effects

[14] As described above, in the case where the pressure in the plant or the apparatus is

higher than the water pressure, or when the pressure of the outlet pipe becomes higher than that of the inlet pipe by the water hammer caused by the rapid opening and closing of the valve, the present invention can prevent the backflow of the water in the circulating pipe, thereby improving the efficiency of the product.

[15] While this invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiment and the drawings, but, on the contrary, it is intended to cover various modifications and variations within the spirit and scope of the appended claims. Brief Description of the Drawings

[16] The foregoing and other objects, features and advantages of the present invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings in which:

[17] FIG. 1 is a sectional view showing a conventional water supply valve;

[18] FIG. 2 is a sectional view showing a water supply valve having a backflow prevention function according to an embodiment of the present invention;

[19] FIG. 3 is a sectional view showing a water supply valve having a backflow prevention function according to another embodiment of the present invention; and

[20] FIG. 4 is a section view showing a water supply valve having a backflow prevention function according to still another embodiment of the present invention. Best Mode for Carrying Out the Invention

[21] Hereinafter, the preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

[22] FIG. 2 is a sectional view showing a water supply valve having a backflow prevention function according to an embodiment of the present invention, FIG. 3 is a sectional view showing a water supply valve having a backflow prevention function according to another embodiment of the present invention, and FIG. 4 is a section view showing a water supply valve having a backflow prevention function according to still another embodiment of the present invention.

[23] As shown in FIG. 2, the water supply valve having a backflow prevention function according to the present invention includes a pipe assembly 20 in which fluid is introduced and discharged so as to circulate. The pipe assembly 20 is provided with a fluid chamber 21 with an upper portion opened, an inlet pipe 22 extending through a side of the fluid chamber 21, a leading end of which is bent upward, and an outlet pipe 23 connected to the other side of the fluid chamber 21.

[24] A bellows 30 is mounted over the opened upper portion of the fluid chamber 21 of the pipe assembly 20. The bellows 30 opens and closes an opening of the inlet pipe 22

and has an outlet hole 31 formed in a portion thereof.

[25] On the other hand, a cover 40 is assembled with the fluid chamber 21 at the upper portion of the fluid chamber 21 to cover the bellows 30, and has a spring reception recess 42 formed therein in which a buffer spring 41 is received so as to compress the bellows 30.

[26] As shown in FIGS. 3 and 4, meanwhile, the second fluid chamber 50 is formed and connected to the inlet pipe 22 of the pipe assembly 20. The second fluid chamber 50 has a water inlet pipe 51 connected to a side thereof. Further, an opening is formed at an upper portion of the second fluid chamber 50. An expandable bellows plate 55 is coupled to the second fluid chamber 50 and has a water inlet hole 53 and water outlet hole 54 formed therein. The water outlet hole 54 of the bellows plate is communicated with the inlet pipe 22. An upper cover 56 is assembled with the second fluid chamber 50 so as to cover the bellows plate 55. The upper cover 56 is provided with a plunger 59 resiliently suspended thereto by a spring 60, and a rubber rod 58 attached to the lower end of the plunger 59. The upper cover 56 is raised and lowered by a solenoid 57 to enable the rubber rod 58 of the plunger 59 to open and close the water outlet hole 54 of the bellows plate 55.

[27] Such a second fluid chamber 50 may be formed at a side or an upper portion of the fluid chamber 21.

[28] The second fluid chamber has the same configuration as the conventional water supply valve, the outlet pipe of which is connected to the water supply valve of the present invention so as to carry out the prevention of the water backflow as a part of the present invention.

[29] Hereinafter, the operation and effect of the present invention will be described.

[30] As shown in FIG. 2, first, when circulating water is introduced into the fluid chamber 21 through the pipe assembly 20, the pressure P4 in the inlet pipe 22 raises and expands the bellows 30, so as to allow the circulating water to flow from the inlet pipe to the outlet pipe. On the other hand, if the pressure P6 in the outlet pipe 23 increases, the circulating water is introduced through the outlet hole 31 of the bellows 30 into the upper cover 40. Then, when the pressure P5 by the plunger of the upper cover 40 is equal to the pressure P6 of the outlet pipe, the bellows 30 descends by the elasticity of the spring 41 to close the opening of the inlet pipe 22 and prevent the backflow of the circulating water.

[31] As shown in FIG. 3, although the combination of the water supply valve having the backflow prevention function and the conventional water supply valve having no the backflow prevention function shown in FIG. 1 can be used, it is possible to prevent the backflow of the water within the water supply valve. Further, as shown in FIG. 4, the conventional water supply valve may be formed over the water supply valve of the

present invention. In the combination of the water supply valves shown in FIG. 4, when the electricity is applied to the solenoid 57, the solenoid 57 operates and enables the plunger 59 to be raised and lowered so that the rubber rod 58 opens the outlet hole 54 of the bellows. Therefore, the circulating water is introduce through the inlet pipe 22 into the upper fluid chamber, and the bellows 30 is lifted up by the pressure of the introduced water, resulting in the flow of the circulating water through the outlet pipe 23.

[32] Meanwhile, if the pressure of the outlet pipe is greater than that of the inlet pipe, the bellows plate closes the opening of the outlet pipe, thereby preventing the backflow of the circulating water. Industrial Applicability

[33] The present invention can be applied to boilers, and prevent the backflow of the circulating water in the circulation pipe even though the back pressure is generated in the valve by the water hammer occurring when the valve is raised and lowered in the case where the pressure in a plant or apparatus is greater than the water pressure.