JPH071079B2 - Free float steam trap - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention utilizes the difference in specific gravity between steam and condensate to directly open and close the valve opening with a free float accommodated in the valve chamber in a free state to recover steam and condensate. The present invention relates to a free-float steam trap that automatically discharges only condensate from a water mixture system, and particularly to a free-float steam trap that can discharge more condensate.

<Prior Art> As a free float type steam trap that attempts to increase the discharge flow rate of condensate, for example, there is one disclosed in Japanese Patent Publication No. 51-12851. This opens the valve opening at the bottom of the valve chamber,
By directly opening and closing this valve opening on the surface of a substantially spheroidal oblong float placed inside the valve chamber, the valve opening moment due to buoyancy is increased and the large valve opening is opened and closed to obtain a larger discharge flow rate. It was an attempt.

<Problems to be Solved by the Present Invention> In the above case, the valve opening moment is increased by making the float horizontally long, and the discharge flow rate is increased accordingly. However, by making the float horizontally long, the valve casing becomes There was a growing problem. Since steam traps are often installed in terminals such as various steam-using equipment and steam pipes, or in small spaces at the end of pipes, their size is naturally limited, and the fact that the casing is large means that it is the material of the casing. It was a problem because the cost was high.

The technical problem of the present invention is to increase the discharge flow rate of a free float type steam trap without increasing the size of the free float, that is, without increasing the size of the valve casing.

<Means for Solving the Problems> An inlet and an outlet are formed in a valve casing having a valve chamber, and a valve port communicating with the valve chamber and the outlet is provided by projecting into the valve chamber and opening depending on the liquid level in the valve chamber. In a steam trap in which a float that floats and descends is accommodated in a free state, and the valve opening is opened and closed on the outer surface of the float, an inlet is formed in the upper part of the valve chamber, and the inlet and the valve chamber are formed into a small hole. The inlet flow, which is communicated via the inlet and flows down into the valve chamber through the small hole of the inlet, is made to flow down to the valve opening side surface on the upper surface of the float and from the center axis of the float.

<Action> When the free float steam trap valve is opened, the float is sucked toward the valve opening by the high-speed fluid flowing through the valve opening. Therefore, one point of the annular valve seat that forms the valve opening is used as the fulcrum to center the float. The buoyancy that acts acts as a rotational moment. Therefore, when the float rises to the same position, when it rises with one point of the valve seat as a fulcrum, and when it rises straight upward, the opening degree of the valve opening, that is, the valve opening The lift amount of the float from is increased, and the discharge flow rate is also increased.

By making the inlet flow to the valve chamber flow down from the center axis of the float to the surface on the valve opening side, the float that rises while rotating with one point of the annular valve seat forming the valve opening as the fulcrum It receives a force in the separating direction from the inlet fluid and separates from the fulcrum of the annular valve seat.

<Example> An example showing a specific example of the above technical means will be described.
(See FIG. 1) A lid 2 is fastened to a main body 1 with bolts 3 to form a valve casing having a valve chamber 4 inside. A gasket 5 is interposed between the main body 1 and the lid 2 to keep them airtight.

An inlet 6 is formed in the upper part of the body 1 and an outlet 7 is formed in the lower part. The inlet 6 communicates with the upper portion of the valve chamber 4 through the small holes 20 and 21, and is connected to a steam-using device (not shown) or the like to introduce condensed water into the valve chamber 4. A valve seat member 11 having a valve opening 10 is screwed to a lower portion of the main body 1 via a gasket 12. The inlet 6 is arranged above the valve opening 10 so as to communicate with the valve chamber 4. The valve port 10 communicates the valve chamber 4 and the outlet 7 through the communication passage 13, and guides the condensed water of the valve chamber 4 to the outlet 7. The communication passage 13 has a cross-sectional area that is sufficiently larger than that of the valve opening 10, has a gradually widening shape in which the pipe resistance portion such as a bent portion is eliminated as much as possible, and is formed substantially coaxially with the outlet 7. The inlet 6 and the outlet 7 are opened in the horizontal direction, and each form an internal thread for piping.

A hollow spherical float 8 made of a stainless steel thin plate is accommodated in the valve chamber 4 in a free state. The inlet flow flowing from the inlet 6 into the valve chamber 4 is arranged so as to flow toward the valve port 10 side with respect to the central axis of the float 8. The float 8 floats on the condensed water accumulated in the valve chamber 4 and ascends and descends together with the liquid surface. Two float seats 26 are formed on the bottom surface of the valve chamber 4 substantially parallel to the central axis of the valve port 10 on the front side of the drawing to hold the float 8 when the valve is closed.

Reference numeral 15 is a bimetal piece, which is formed in a substantially U-shaped cross section and is attached to the main body 1 with a screw 16, and is deformed at low temperature to float 8.
Is separated from the valve seat member 11 to open the valve port 10 and contracts at high temperature (state shown in FIG. 1) so that it does not participate in the float 8.

The operation of the steam trap is as follows. Entrance 6
Is connected to the condensate generation place such as steam-using equipment. Condensate and steam flow into the valve chamber 4, and condensate is separated into a lower part and steam is separated into an upper part and accumulated. As the liquid level rises, the float 8 floats around one point of the valve seat member 11 as a fulcrum (indicated by a chain line in FIG. 1). Since the fluid from the inlet 6 flows down to the surface of the right half of the floating float 8,
Upon receiving a fluid force in a direction away from the valve port 10, that is, to the left, the valve seat member 11 separates from the fulcrum and rises straight upward. By rising straight, the valve opening of the valve opening 10 becomes large, and the discharge flow rate of the steam trap increases accordingly.

When the liquid level drops due to discharge, the float 8 also descends, closing the valve port 10 and stopping the outflow of condensate. In this case, since the float seat 26 is formed in two lines parallel to the central axis of the valve opening 10, the float 8 that has descended abuts the float seat 26 and at the same time sits on the valve seat member 11 to complete the valve opening 10. To block.

<Effects of the Invention> The float separates from the valve seat member during valve opening, so that the lift amount between the float and the valve opening, that is, the valve opening degree increases and the discharge flow rate increases.

Further, since the communication passage that connects the valve opening and the outlet is formed to have a shape with low conduit resistance and is formed substantially coaxially with the outlet, the pressure loss at the outlet is reduced and the discharge flow rate can be further increased. .

[Brief description of drawings]

FIG. 1 is a sectional view of a free float type steam trap according to an embodiment of the present invention. 1: Main body, 2: Lid 4: Valve chamber, 6: Inlet 7: Outlet, 8: Float 10: Valve port, 11: Valve seat member 13: Communication passage, 26: Float seat

Claims (1)

[Claims] 1. An inlet and an outlet are formed in a valve casing having a valve chamber, and a valve port communicating with the valve chamber and the outlet is provided by projecting into the valve chamber and is floated down according to the liquid level in the valve chamber. In a steam trap that accommodates a float in a free state and opens and closes the valve opening on the outer surface of the float, an inlet is formed in the upper part of the valve chamber, and the inlet and the valve chamber are communicated via a small hole. Then, a free-float type steam trap in which an inlet flow that flows down into the valve chamber through the small hole of the inlet flows down to the valve opening side surface on the upper surface of the float and from the center axis of the float.