JPH0356779A - Thermo-valve - Google Patents

Abstract

PURPOSE:To ensure automatic and reliable valve closing by providing a bias spring for keeping a drain valve open with the partial force of the upstream pressure of a condensing pipe acting against a valve closing force, and a shape memory alloy spring for generating a force overriding a difference between the aforesaid forces with the recovery of the shape memory to the original state thereof due to a rise in condensed water temperature. CONSTITUTION:A push rod 11 is pressed down with an adjustment spindle 13 and a drain valve 1 is thereby opened against the force of a return spring 3 for discharging initial condensed water. When the push rod 11 is pressed down, a shape memory alloy spring 9 is plastically deformed due to compression. Consequently, even when the adjustment spindle 13 is returned, a valve opening condition is maintained with the partial force of a bias spring 21. While the temperature of condensed water is rising, water is continuously discharged. When water temperature reaches the predetermined level, the shape memory alloy spring 9 is restored to the memory shape thereof and generates a reaction force to override the bias spring 21 via a through-hole, thereby lifting a valve stem 6. As a result, the drain valve 1 closes due to the return spring 3. According to the aforesaid construction, the valve 1 can automatically close without any discharge of fresh steam.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a thermovalve.

In steam equipment such as dryers, one factor that improves productivity is how quickly the condensate accumulated in the equipment and piping when the equipment is stopped is discharged when the equipment is started.

If the steam trap for condensate discharge is determined based on the initial condensate volume, the discharge volume will be approximately 2 to 3 times the normal condensate volume during operation, resulting in a disadvantage of excessive performance. In addition, under steady-state operating conditions during most of the equipment's operating period, optimal operation cannot necessarily be expected, and steam leakage may occasionally occur.

Therefore, it is necessary to quickly eliminate only the initial condensate, and we will propose a thermovalve that can quickly respond to this requirement.

[Conventional technology] In order to eliminate initial condensation, a bypass valve has traditionally been often attached to the steam tonnage knob, and the bypass valve is manually opened by the equipment operation manager, thereby shortening the start-up time of the equipment. However, with these methods, it is difficult to know when the condensate accumulated in the equipment has finished being discharged. By keeping the valve open, the bypass valve has to be closed only when steam is seen escaping downstream, which is a disadvantage; in other words, from an energy saving perspective, not only is there a great deal of waste, but the bypass valve also needs to be monitored during this period. Furthermore, there were other problems such as forgetting to close the bypass valve because the worker was busy with other tasks.

[Problems to be Solved by the Invention 1. The above-mentioned problems associated with removing initial condensate by providing a bypass valve can be advantageously overcome, and the rise in condensate temperature accompanying the removal of initial condensate can be maintained at a predetermined level. It is an object of the present invention to propose a thermovalve that can carry out an automatic and reliable closing when the temperature is reached.

[Means for Solving the Problems] The initial condensate is removed from the inlet 4 to the outlet 5, and this figure shows the closed state after the initial condensate has been discharged.

A valve stem 6 passes through the valve seat 2 and faces the drain valve 1, and is capable of sliding along a stem guide 8 attached to the valve body 7. Reference numeral 21 designates a bias spring that contacts the two end faces of the valve stem 6 and presses down the valve stem 6, and 9 designates a shape memory alloy spring which is shown in a state in which it has finished generating a spring reaction force that opposes the bias spring 21, and 10. is the spring holder.

Reference numeral 11 denotes a push rod that faces the upper end of the valve stem 6 in this example and controls the lowering of the valve stem 6. In this example, the push rod 11 protrudes from the lower end of an adjustment spindle l3 having a handle l2, and extends through the bias spring 21. .

The handle 12 is provided with a lock button 14, and the push rod l1 is activated by the rotation of the adjustment spindle 13 only when a candle (not shown) is removed when operation is necessary.
It is preferable to provide a safety device that prevents accidental valve opening by making it possible to reduce the pressure of the valve.

According to the present invention, the above object is to provide a drain valve that receives a closing force against a valve seat opening toward the downstream side due to the upstream pressure of a condensate pipe, and to provide a drain valve that is biased in a direction that opposes the valve closing force that acts on the drain valve. A bias spring that maintains the drain valve open state by force, and a shape memory that is generated by recovering the memorized shape based on the rise in condensate temperature to a predetermined value, which overcomes the difference between the biasing force and the valve closing force. This is advantageously achieved by a thermovalve comprising an alloy spring and an operating push rod which forces the drain valve to open through compressive deformation of the shape memory alloy spring, wherein the drain valve is particularly designed as a pyronot valve. By providing an actuator that operates in response to upstream pressure caused by opening and a large-diameter valve that is opened secondarily by this actuator, it is also possible to shorten the time required to remove a large volume of initial condensate.

Now, FIG. 1 illustrates the basic configuration of this invention.

In the figure, 1 is a drain valve, 2 is a valve seat, and 3 is a return spring. When the drain valve 1 is removed from the valve seat 2, the stem guide 8 has a conduction hole 15 as shown in the figure. By introducing the condensate discharged to the outlet 5 side into the heat sensitive chamber 16, it is used to operate the shape memory tone metal spring 9.

[Operation] By closing the drain valve 1 shown in the figure, the steam R reactor is operated under timely drainage exclusively by a steam trap with an appropriately selected performance capacity (not shown in the figure), and then the device is closed. is stopped, but when it is restarted, the already mentioned accumulation of condensate occurs.

Then, the handle 12 is unlocked, the adjustment spindle 13 is rotated, and the bunoshronod 11 is compressed to open the drain valve 1 against the return spring 3 via the valve stem 6, thereby removing the initial condensate from the inlet. 4
Although it is clear that the bending rod can be discharged from the hole toward the outlet 5, the compression of the shape memory alloy spring 9 through the spring receiving fitting 10 also causes plastic deformation due to the compression of the shape memory alloy spring 9. Even if the pressure on the valve stem 6 by the push rod 11 is released by returning the pressure, the valve closing force acting on the drain valve 1 when the drain valve 1 is opened is
The biasing force of the bias spring 21 is sufficiently opposed to maintain the valve open state.

By removing this initial condensate, the temperature of the condensate arriving at the inlet 4 increases while the drainage continues, and when this reaches a predetermined temperature, the temperature inside the heat-sensitive chamber 16 communicating through the through hole 15 also reaches the predetermined temperature. At this time, the shape memory alloy spring recovers to its memorized shape and generates a spring reaction force that overwhelms the bias spring 21, causing the valve stem 6 to rise.

As a result, the water hailing valve 1 is moved to the valve seat 2 by the return spring 3.
The valve is closed and the valve is closed.

The closing temperature of drain valve 1 is 90°C, which eliminates the risk of live steam leakage.
°C to 100 °C, and therefore spring 9 using a shape memory alloy that results in recovery of the memory shape at such operating efficiencies.
It is to create.

[Example] Although a specific example of the basic configuration was shown in Figure 1, the example in Figure 2 is a case where a shape memory alloy spring 3' is used instead of the return spring 3 to simplify the structure. The functions are the same as those already described.

3 and 4, a small drain valve 1 having almost the same configuration as that shown in FIG. In order to eliminate condensate, the outlet 5' side of the thermovalve described above is connected to open and close the large-diameter main valve 17 by the piston rod 19 of the actuator 18, which is a piston-cylinder type in this example. It is something to do.

In the figure, 20 indicates a cylinder.

[Effects of the Invention] According to the thermovalve of the present invention, a much larger amount of generated water than the steady state amount is generated at the initial stage of start-up, such as when steam equipment is restarted, when the steam trasob is used to properly remove condensate. By simply adding a forced opening operation to rapidly remove the accumulated low-temperature condensate, the valve can be self-closing in a timely manner when the condensate temperature rises due to the discharged water reaches a predetermined temperature. Selectively eliminates only the accumulated low-a condensate without requiring human intervention, and the flow with the release of live steam disappears, ensuring the valve remains closed unless the next operation (including blow-off during operation) is performed. be able to.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing the basic structure of a thermovalve, Fig. 2 is a sectional view of another embodiment, and Figs. 3 and 4 are pie-port/soto valves for opening/closing large-diameter main valves. FIG.

Claims (1)

[Claims] 1. A drain valve that receives a closing force against a valve seat that opens toward the downstream due to the upstream pressure of the condensate pipe, and a biasing force acting on the drain valve in a direction that opposes the closing force. A bias spring that maintains the open state of the drain valve, and a shape memory alloy that generates a force that overcomes the difference between the biasing force and the valve closing force by restoring the memorized shape as the condensate temperature rises to a predetermined value. A thermovalve characterized by comprising a spring and an operating push rod that forces a drain valve to be forcibly opened through compressive deformation of the shape memory alloy spring. 2. The drain valve is used as a pilot valve, and includes an actuator that operates in response to upstream pressure caused by the opening of the drain valve, and a large-diameter main valve that is secondarily opened by this actuator. The thermovalve described.