JP2544115B2 - Gas vent valve for boiler - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention provides a boiler gas vent valve that automatically degass a boiler when it is started to ensure the safety of the boiler and also reduces the labor of an operator. Regarding the structure.

<Conventional technology and its problems> Boiler feed water that does not remove dissolved gas is under atmospheric pressure.
O ₂ 7.0 (ml / ml) (× 10 ³ ) and N ₂ 13.1 (ml / ml) at 15 ℃
(× 10 ³ ) is included. But at 100 ° C this is zero. For this reason, when starting a boiler, etc., the gas vent valve is opened to release oxygen and nitrogen dissolved in the can water during shutdown, and the boiler pressure is 1.5 kg / cm ² g (saturation temperature 127 ° C).
When this happens, this valve is closed. In addition, when the boiler is stopped, when the boiler pressure is reduced to about 1 kg / cm ² g after extinguishing, the inside of the boiler becomes a vacuum and the members are deformed and damaged, so the gas vent valve is opened to prevent this.

Conventionally, these operations are manually performed by an operator who goes up the gear rally ladder and goes to the degassing valve. Further, at the time of startup, it is necessary to constantly monitor the timing of closing the gas vent valve, and if the closing is too early, the degassing effect will be insufficient, and if the closing is delayed, steam will be unnecessarily discharged. In particular, when the vehicle is stopped, it takes a long time to reduce the pressure because of heat storage, and there is an inconvenience that the operator has to wait in the driver's cab for several hours or ten hours in order to open the gas vent valve. However, if the operation of the gas vent valve is automated, the mental burden and labor of the operator will be greatly reduced, and therefore its appearance has been desired. Such a gas release valve as a simple stop valve was connected to the upper drum 7u of the boiler 7 as shown by reference numeral 8 as shown in FIG. 6, and the discharge pipe 10 was connected to this.
(Note: FIG. 6 shows a case where the gas vent valve 1 according to the embodiment of the present invention is further connected.) Upper drum 7u
Is located far above the floor of the operator's cab, and it takes a considerable amount of time to reach the gas vent valve, especially in large boilers.

<Object of the Invention> An object of the present invention is to propose a structure of a gas vent valve for automatically venting the boiler when the pressure is increased and for preventing an excessive decrease in the drum internal pressure when the boiler is stopped.

<Outline of means> The valve is closed by a potting operation (bouncing up or down with a pop is referred to as popping or popping) at a specified pressure when the boiler pressure is increased, and when the can is stopped, the valve is opened at a specified pressure by popping. As shown in the above, the valve body is provided with a popping groove for popping, and the pressing force of the spring corresponding to the predetermined boiler pressure is adjusted by the pressure adjusting ring, and when the constant pressure is reached, it is automatically and potted. The valve is opened.

<Example> An example of the present invention will be described with reference to the accompanying drawings.

In FIG. 1, when boosting the pressure of the boiler, the stepped portion 2c of the valve body 2 is in contact with the upper end surface 5a of the internal space of the valve body receiving main body 5, so the gap C for the steam passage having the dimension l ₁ shown in FIG. (Sign
(Indicated by 19) is retained. Therefore, for a specified pressure of 1.5 kg / cm ² g, the boiler can water has a saturation temperature (127
(° C), the O ₂ and N ₂ that had been dissolved and absorbed will be sufficiently released and discharged. The gas (O ₂ , N ₂ ) is gradually released until it becomes the vapor of this pressure, and then flows through the vapor flow path in the order of reference symbols a, b, c, d to be discharged.

When the flow rate of steam increases, the steam flow collides with the pump groove 11 on the lower surface of the valve body plate having a substantially semicircular cross section as shown in the figure, and the valve body 2 is instantly displaced upward at a predetermined pressure at the predetermined pressure. Body seat
2d and the valve seat 13 of the spring receiving main body 14 are brought into contact with each other, and the gas vent valve 1 is instantly and automatically closed (closed by popping). After that, the closed state is maintained even if the drum internal pressure rises. An upper end surface 18 of the valve body receiving main body 5 and an outer peripheral side lower surface 17 of the spring receiving main body 14 are tightly connected to each other by a cap nut 6 via a packing 20 which is a tight fixing means.

The pressing force of the spring 3 against the valve body 2 is designed to operate at a specified pressure corresponding to the force of the popping operation, and if necessary, the pressure regulating ring 4 located at the upper end of the spring or the steam of the spring receiving body. Fine pressure adjustment can be performed by utilizing the screw engagement with the threaded portion 21 of the passage wall. The adjustment can be facilitated from the outside of the gas vent valve by utilizing the protrusion 4a protruding on the inner circumference of the pressure adjusting ring 4.

When the can is stopped, when the pressure in the drum drops to a predetermined pressure such as 0.5 kg / cm ² g as the pressure in the boiler drops, the valve element 2 opens the down valve by the force of the spring 3 and the steam passage e is formed. . Even in this case, the valve seat is not
Since there is the same groove 12 having a semicircular cross-section on the outer peripheral side of 13, the opening operation is smoothly performed by the popping operation.

As shown in FIG. 6, the gas vent valve 1 has a stop valve 8 and a discharge pipe.
Since it is located between 10, the stop valve 8 can be closed when the operation of the degassing valve is unnecessary.

When the valve is opened, the force of the spring 3 and the static pressure on the back surface of the valve body 2 act as a relation, but when the valve is closed, the valve 2 is closed at a pressure higher than the static pressure when the valve is opened. Select the shape of the pop groove and design the cross-sectional area of the fluid passage b. This enables the gas vent valve to operate with different pressures when the valve is closed and when it is opened.

<Effects of the Invention> A large number of meters, automatic valves, or the power associated therewith are required when attempting to make them fully automatic by using the signals of the meters (pressure gauge, thermometer, etc.). As a result, the degassing valve automatically closes at a constant pressure during the pressurization process to reduce the labor of the operator and obtain an accurate valve closing operation. Also, when the pressure was stopped, the air vent valve was opened for a few hours in the past when the pressure was stopped, but it is not necessary to wait, and the gas vent valve is automatically opened by itself, and the safety of the boiler is obtained and a great labor saving effect is obtained.

Especially, save a lot of labor when starting and stopping every day,
The implementation of the present invention is extremely effective.

[Brief description of drawings]

1 is a longitudinal sectional view of a gas vent valve according to an embodiment of the present invention, FIG. 2 is a sectional view taken along the line I--I of FIG. 1, and FIG.
Fig. 4 is a perspective view of the pressure regulator ring as seen from the side of the stem 2a, Fig. 4 is a plan view of the pressure regulating ring, Fig. 5 is an enlarged partial view of the flow path showing the steam flow of the boiler, and Fig. 6 is a gas vent valve on the upper body of the boiler. 2 is a schematic drawing showing a state in which the are connected. 1 ... Gas vent valve, 2 ... Valve body 2a ... Stem part, 2b ... Valve body plate-like part 3 ... Spring, 4 ... Pressure adjusting ring 5 ... Valve body receiving body, 6 ... Cap nut 8 ...... Stop valve, 10 …… Discharge pipe 11 …… Pop groove, 12 …… Peripheral groove 14 …… Spring receiver body

Claims (1)

(57) [Claims] 1. Air in a pressure vessel containing liquid and air,
In a device for automatically removing only air by popping a valve, a gas release valve (1) and a release pipe (10) are connected in series to a gas release stop valve provided in a boiler upper body, and inside the gas release valve (1) Valve body (2), spring (3), in order from the upper body side to the steam passage of
The pressure regulating ring (4) of the spring is positioned, a spring receiving seat is provided on the upper surface side of the valve, and a circumferential pop groove (1
The valve plate-like portion (2b) provided with 1) and the stem portion (2a) which forms a part of the vapor passage and forms a part of the steam passage by a plurality of stepped partition portions (16) positioned at equal angular intervals. Disc (2)
And a spring receiving main body (14) having a valve seat facing the upper valve seat (2d) of the valve body (2) on its lower surface side, and the upper valve seat and the lower valve seat are used for valve popping. As the gas passage with an appropriate interval, and the adjusting ring (4) is screwed into the screw part in the spring receiving main body (14) as the pressure adjusting part for adjusting the spring (3). A gas vent valve for boilers that automatically vents air due to changes.