JPS61149673A - Flow control mechanism in flow control valve - Google Patents

Abstract

PURPOSE:To simplify the constitution of a flow control mechanism and to set flow characteristic arbitrarily by forming a flow throttle surface on the side opening and closing a nozzle inner hole of a piston valve element sliding in the axial direction a cage valve body. CONSTITUTION:A piston valve element 4 is inserted in a cage valve body 1 and slid in the axial direction by a valve shaft 5, thereby to sequentially open or close nozzle inner holes 2. A flow throttle surface 4a is formed on the outer peripheral portion of the side of the piston valve element 4 that is adapted to open and close a nozzle inner hole. A flow characteristic can be set arbitrarily by simply changing a flow throttle surface, and especially the mechanism can be designed with allowance for the deterioration of a characteristic change depending upon fluid erosion abrasion to contribute to lengthening the life of a product.

Description

Detailed Description of the Invention [Objective of the Invention 1 Above 1] The present invention relates to a flow control valve used in piping systems such as process automation, particularly a cylindrical cage valve having a large number of nozzle inner holes on the inner surface of the valve body. This invention relates to a flow rate side WI lug structure in a flow rate control valve consisting of a cylinder and a piston valve element that slides in the axial direction within the cage valve body to open and close a nozzle inner hole.

Hesitation! 1. Conventionally, among these types of flow control valves, especially those that cannot be arranged so that the nozzle inner holes contact or overlap in the axial direction, the opening of the nozzle inner hole increases and decreases as the piston valve body moves. Since the total area changes discontinuously, the amount of displacement of the piston valve body and the amount of ejection from the nozzle are not completely linearly proportional, but change in stages, which may affect the stability of the flow rate control value. There was a problem with control accuracy.

In order to solve this problem, for example, as shown in FIGS. 9(A) and 9(B), a large number of nozzle inner holes 21 are formed in the inner wall of the cage valve body 20 in a semicircular shape, and these nozzle inner holes 21 are connected to the piston valve body ( (not shown), the flow rate from the nozzle 22 can be minutely changed in accordance with the displacement of the piston valve body, or the nozzle inner hole 23 can be opened or closed with a slit as shown in FIG. There are 11 flow control means which are formed into a shape to continuously adjust the flow rate.

However, in the conventional flow rate adjustment means described above, the structure of the nozzle inner hole 21, 23 is complicated, making it difficult to process, requiring a large amount of processing time, special processing equipment, etc., and resulting in high manufacturing costs. In addition to this, there is also the risk of clogging due to foreign matter, and the flow characteristics are insufficient.

The present invention has been made in order to eliminate the drawbacks of the conventional flow control valves described above.The purpose of the present invention is to provide a flow control valve that has a simple structure, can be manufactured at low cost, and has a flow rate adjustment mechanism with excellent flow characteristics. There is a valve to provide.

[Structure of the Invention] The flow rate adjustment mechanism in the flow rate control valve of the present invention for controlling the flow rate includes a cylindrical cage valve body having a large number of axially spaced nozzle inner holes, and a tube inside the cage valve body. In a flow control valve consisting of a piston valve body that slides in the axial direction to open and close the nozzle inner hole,
The present invention is characterized in that a flow rate restricting surface is formed on the nozzle inner hole opening/closing side of the piston valve body.

fruit 1 ■ vomit Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 1, reference numeral 1 denotes a cylindrical cage valve body, and a number of nozzle inner holes 2 are opened in the lower inner surface of the cage valve body. As shown in FIG. 2, the nozzle inner holes 2 are arranged in three rows that are slightly shifted in the axial direction, and spray nozzles 3 are fitted radially into each row as shown in FIG. PIIJ3. In addition to a circular hole, the nozzle inner hole 2 may be an ellipse with an length ratio of 2 or less, a square, a square formed by divided circles, or a regular polygon having a square or more shape.

A piston valve body 4 is inserted into the cage valve body 1, and is slid in the axial direction by a valve shaft 5 to sequentially open or close the nozzle inner hole 2.

A flow rate restricting surface 4a is formed on the outer periphery of the piston valve body 4 on the nozzle inner hole opening/closing side (upper side in this embodiment).

FIG. 14 shows a first embodiment of the flow rate restricting surface 4a, in which a conical surface 4a' defined by the following dimensions is formed. That is, the angle θ between the ridgeline of the conical surface 4a' and the axis is jan-'0.
06d/p≦θ≦tan-10.3d/p, and the axial length H of the conical surface 4a' is H≧p-d, where,
d is the diameter of the nozzle inner hole 2, p is the axial pitch of the nozzle inner hole 2, and the range is 20d≧p≧2d.

Moreover, FIG. 5 shows a second embodiment, in which the flow restricting surface 4
A is formed on a spindle surface 4a'' which is an outwardly convex rotating body surface defined by the following dimensions.

That is, the difference δ in radius between the upper and lower end positions of the spindle surface 4a'' is
0.06d≦δ≦0.5d, and the axial length H of the spindle surface 4a# is H=p-d/2, where d is the diameter of the nozzle inner hole 2, and p is the nozzle inner hole. The pitch in the axial direction of 2 is in the range of 20d≧p≧2d.

In FIG. 1, 6 is a liquid inflow path, and 7 is a piston ring.

Fig. 6 shows a temperature reduction device for superheated steam using a flow rate control valve equipped with the above-mentioned 8% flow rate adjustment mechanism.
The thermosensitive tube 9 is placed on the downstream side thereof.

The steam temperature determined by the heat sensitive cylinder 9 is transmitted to the temperature setting regulator 11 through the thermocouple lead wire 10, and compared with the set steam temperature.

Here, when a difference from the set steam temperature is detected, a water injection amount operation signal is transmitted to the valve body 5 knob 13 through the lead wire 12, and by operating the Giraflam 14, the valve stem 5 is
The piston valve body 4 is made to slide through the piston.

Cold water is introduced into the liquid inflow path 6 in the cage valve body 1, and is sprayed into the steam pipe 8 from the nozzle inner hole 2 opened by the piston valve body 4 to reduce the temperature of the superheated steam.

Figure 7 shows the flow rate characteristics of the conventional slit-type nozzle inner hole shown in Figure 10, where rapid opening characteristics can be seen everywhere.
Although a flow rate dead zone is also seen in the central part, FIG. 8 shows the flow rate characteristics due to the flow rate node II mechanism of the above embodiment of the present invention, and it can be seen that the flow rate is sufficiently linearized for practical use.

[Effect of the invention] Next, the effects of the present invention will be listed.

(1) Since a conical flow restricting surface, for example, is simply formed on one side of the piston valve body, it can be manufactured easily and at low cost.

(2) Since there are no restrictions on the size, shape, arrangement, etc. of the nozzle inner holes, the valve body can be shortened as necessary, and the stroke of the piston valve body can be shortened, which can be advantageously applied in terms of design.

(3) By changing the flow restricting surface to WRl, the flow rate characteristics can be set arbitrarily, and in particular, it can be designed based on fluid two-lobed tongue wear (by anticipating the deterioration of characteristic changes), which contributes to a longer life of the product. I can do it.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing an embodiment of a flow control valve equipped with a flow rate adjustment mechanism of the present invention, with the right half showing a fully open state;
The left half shows the fully closed state. Fig. 2 is a front view showing the arrangement of the nozzles in Fig. 1, Fig. 3 is a cross-sectional view showing the radial orientation of the nozzles in Fig. tJ & 1, and Fig. 4 is a first implementation of the flow restricting surface in the piston valve body. An explanatory diagram showing an example, FIG. 5 is v! of the flow restricting surface. An explanatory diagram showing the J2 embodiment, Fig. 6 is an explanatory diagram of a superheated steam temperature reduction device, Fig. 7 is a graph showing the flow rate characteristics of a conventional flow control valve, and Fig. 8 is a flow rate by the flow control mechanism of the present invention. Graph No. 9, 101J showing the characteristics is an explanatory diagram of a conventional flow control valve. DESCRIPTION OF SYMBOLS 1... Cage valve body, 2... Nozzle inner hole, 3... Spray nozzle, 4... Piston valve body, 4a... Flow rate restricting surface, 4a'... Conical surface, 4a''・・Spindle surface, 5・・
・Valve shaft, 6...Liquid inflow path, 7...Piston ring,
8... Steam pipe, 9... Before temperature sensing, 10-... Thermocouple lead wire, 11... Temperature setting controller, 12... Lead wire, 13... Valve positioner, 14 ... Guiraflam. '' Figure 4 Figure 5 Figure 6 Figure 6 d 8 Figure 7 - Injection water 1 4'hr (Differential pressure 10 kg/cm" room temperature water) Figure 8 - Injection water amount j/hr (Differential pressure 10 kg/l: r+v' room temperature water) Figure 9 (A) Figure 10

Claims (1)

[Scope of Claims] (1) A cylindrical cage valve body having a large number of axially spaced nozzle inner holes, and a piston that opens and closes the nozzle inner holes by sliding in the axial direction within the cage valve body. 1. A flow rate control valve comprising a valve body, characterized in that a flow rate restricting surface is formed on the nozzle inner hole opening/closing side of the piston valve body. (2) Claim 1, wherein the flow rate restricting surface is a conical surface defined by the following dimensions:
Flow rate adjustment mechanism described in section. The angle θ between the ridgeline of the conical surface and the axis is tan^-^10.06d/p≦θ≦tan^-^10
．． 3d/p, and the axial length H of the conical surface is H≧p−d, where d is the diameter of the nozzle inner hole, p is the annular pitch of the nozzle inner hole, and 20d≧p≧2d. The range shall be . (3) The first aspect of claim 1, wherein the flow rate restricting surface is a spindle surface defined by the following dimensions.
Flow rate adjustment mechanism described in section. The difference δ in radius between the upper end position and the lower end position of the spindle face is 0.06d≦δ≦0.5d, and the axial length H of the spindle face is H=p−d/2 where where d is the diameter of the nozzle inner hole, p is the pitch of the nozzle inner hole in the annular direction, and is in the range of 20d≧p≧2d.