JPH0742000Y2 - steam trap - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a downward bucket steam trap for automatically discharging condensate in a steam apparatus or steam piping.

[Problems to be solved by conventional techniques and devices]

In a normal so-called downward bucket steam trap, a large amount of air cannot be extracted because only a small hole for removing air is opened in the bucket. That is, FIG. 4 shows a structural example of such a conventional steam trap. In the figure, 1 is a valve box having an inlet 1a and an outlet 1b, and 2 is suspended downward in the valve box 1. bucket,
3 is a strainer, 4 is a strainer chamber, 5 is a passage that connects the inlet 1a and the strainer chamber 4, 6 is a weight fixed to the center of the bucket 2, 7 is a retaining ring for fixing the weight 6, and 8 is fishing. Metal fittings, 9 is a lid, 10 is a gasket, 11 is a passage formed in the lid 9 communicating with the outlet 1b, 12 is a valve seat having a valve seat opening 12a, 13 is one end pivotally connected to the support tool 15 via a connecting pin 14. The lever 16 is attached to the lever 13 and has the other end supporting the tip of the fishing rod 8, and 16 is a valve body fixed to the lever 13 by a retaining ring 17. Although the small holes 2a for venting air described above are provided in the ceiling of the bucket 2, a large amount of the large amount of pipes and devices existing in the pipes and devices initially installed to vent the pipes and devices in which such downward bucket steam traps are installed. Air must be expelled quickly. In this case, if the air is not discharged and stays in the piping device, not only the average temperature of the steam is lowered but also the heat transfer coefficient of the entire device is lowered because the thermal conductivity of the air is small.
Further, there has been a problem that the constituent oxygen of the device is corroded by the oxygen in the staying air.

However, the above steam trap cannot exhaust the air rapidly, and as shown in FIG.
When the temperature is low at the beginning of ventilation, by installing a bimetal 18 that can bend to push down the bucket 2 as shown by the dotted line in the figure, air is forcibly discharged through the valve seat opening 12a together with low temperature condensate. Something like that is proposed. On the other hand, another structure example for performing forced discharge of air at such a low temperature is shown in FIG. 6. According to this example, the push pin 19 that can act on the fishing rod 8 of the bucket 2 is pushed up. At the time of low temperature, the bias spring 21 pushes down the bucket 2 via the push pin 19 against the elastic force of the bimetal plate or the shape memory alloy spring 20 which causes air to be discharged from the valve seat opening 12a. ing. In the case of the example of FIG. 6, the weight 6 ′ is fixed to the lower end of the bucket 2.

However, in the steam trap shown in FIGS. 5 and 6, when the bucket 2 is pushed down by the bimetal 18 or the bias spring 21, the bucket 2 is filled with air, so that the bucket 2 is not filled with air. A large buoyancy acts, and a sufficient amount of pushing down force is required to overcome this buoyancy and push down the bucket 2. Therefore, the bimetal 18 or the bias spring 21 must have a large and sturdy structure, and further, the bimetal plate or the shape memory alloy spring which should oppose the bias spring 21.
20 also had to be enlarged. As a result, there is an inconvenience that the steam trap itself inevitably becomes large in size and the price thereof becomes high.

Further, FIG. 7 shows an example of a structure proposed to solve such a problem as the size increase. This is to provide a large diameter hole 2a 'in the bucket 2 and close the hole 2a'. A possible air vent valve body 22 is connected to a bimetal 23. But,
In the case of this example, practically, the operation of the air vent valve body 22 becomes unstable, so that the hole 2a ′ cannot be completely closed, and there is a risk of air leakage.

In view of such circumstances, an object of the present invention is to provide a downward bucket steam trap of this type provided with an inexpensive air bleeding mechanism that ensures a reliable operation without increasing the size.

[Means for Solving the Problems] In the steam trap according to the present invention, a guide rod also serving as a weight is fixed to the center of the bucket, and a bias spring, an air vent valve body and a shape memory alloy are connected in series along the guide rod. The spring or the bimetal plate is loosely inserted, and the air vent valve body can open and close the second air vent hole in the ceiling portion of the bucket.

[Action]

According to the present invention, the shape memory alloy spring or the bimetal plate is compressed by the elastic force of the bias spring and the air vent valve body has the second air vent hole at the low temperature at the start of ventilation. As a result, a large amount of air from the inside of the bucket is quickly and completely discharged to the outside of the steam trap through the second air vent hole, the valve seat opening, and the like. Further, as a result of the elasticity of the shape memory alloy spring or the bimetal plate being closed by the steam at high temperature, the air vent valve body closes the second air vent hole, so that the valve seat opening is closed to prevent the steam from leaking.

〔Example〕

An embodiment of the downward bucket steam trap according to the present invention will be described below with reference to FIGS. 1 and 2 by using the same reference numerals for the same members as the conventional example. Fig. 1 shows the state at low temperature when condensate and air are discharged, and Fig. 2 shows the state at high temperature when condensate is not discharged. , 24 is a strainer, 25 is a partition plate having a hole 25a, and these are stepped portions formed at the bottom of the valve box 1.
It is installed in 1c and is fixed to the valve box 1 by a retaining ring 26 elastically attached to the tapered portion 1d.

Here, the bucket 2 has an air vent hole 2a in its ceiling.
Is provided in the same manner as in the conventional example, but at least one second air vent hole 2b having a diameter several times larger than the diameter of the air vent hole 2a is additionally provided. . Further, in the figure, 27 is a bias spring wound around the guide rod 6, and 28 is an outer diameter portion 28a on the upper end surface side thereof which can surround the second air vent hole 2b and a bottom portion 28b.
Is an air bleeding valve body loosely inserted into the guide rod 6 while being biased downward by a bias spring 27, 29 is a shape memory alloy spring which is set so as to recover its elasticity at high temperatures, and 30 is a presser foot. It is a ring. On the other hand, the upper end of the guide rod 6 is provided with a support shaft 6a protruding above the ceiling portion of the bucket 2, and the support shaft 6a is inserted into an engaging hole 13a formed at one end of the lever 13. . The coil spring 3 is attached to the support shaft 6a.
Although 1 is wound, the retaining ring 32 prevents the support shaft 6a from coming off.

Since the steam trap of the present invention is configured as described above, first, at the start of ventilation, the low temperature condensate and air coming from the inlet 1a pass through the passage 5 and the strainer 24.
The dust or the like is filtered by the filter and further flows into the valve box 1 through the hole 25a of the partition plate 25. Then, the water enters the bucket 2, but at this time, since the condensate water and the like are at a low temperature, the shape memory alloy spring 29 is compressed by the biasing spring 29 and the air vent valve body 28 is pushed down. The second air vent hole 2b is open. Therefore, the air flowing into the bucket 2 passes above the bucket 2 through the second air vent hole 2b, and at this time, the bucket 2 itself is brought to the lower position (see FIG. 1) by the weight of the guide rod 6. Therefore, a large amount of air is discharged from the outlet 1b through the valve seat opening 12a in which the valve body 16 is open. When the condensate and air are discharged and the next high-temperature steam flows into the valve box 1, the shape memory alloy spring 29 is heated,
The shape is restored to restore the original elasticity of the spring, and thereby the air vent valve body 28 is pushed up against the elasticity of the bias spring 27, so the second air vent hole 2b is closed by the air vent valve body 28. Be punished. As a result, the bucket 2 is caused to have a buoyancy force by the steam, and floats from a position below the bucket 2, and the lever 13 via the coil spring 31.
Rotate. Then, as shown in FIG. 2, the valve seat opening
The valve body 16 closes the valve 12a to prevent steam from leaking from the outlet 1b. After that, it operates in the same manner as a normal bucket trap, that is, it is discharged at any time so that condensed water does not stay.

In this way, a large amount of air can be quickly discharged especially at the start of ventilation, but the bias spring 27, the air vent valve body 28
And the shape memory alloy spring 29 is loosely inserted in series along the guide rod 6, and therefore the air vent valve body 28 operates smoothly by the guide of the guide rod 6, so that a large amount of residual air can be promptly discharged. It is extremely advantageous.

The coil spring 31 in the above-described embodiment acts as a buffer for the valve seat 12 of the valve body 16 when the bucket 2 floats, but in the case of a small trap, when the bucket 2 floats. Since the impact generated on the valve body 16 is relatively small, in such a case, instead of using the coil spring 31, use a fishing tackle (see FIG. 4) for suspending the bucket 2 on one end of the lever 13. It doesn't matter. FIG. 3 shows the circumference of a bucket using a doughnut-shaped bimetal plate 29 'in place of the shape memory alloy spring 29 shown in FIGS. 1 and 2, and its function and operation are shown in FIGS. Since it is the same as that described in step 1, detailed description will be omitted. In addition, the shape memory alloy spring 29 or the bimetal plate 2
The temperature characteristics of 9 ', etc. can be set as appropriate particularly in relation to the bias spring 27.

[Effect of device]

As described above, according to the present invention, a guide rod as a weight for adjusting the weight of a bucket is simply fitted to the center of the bucket to guide the bias spring, the air bleeding valve body and the shape memory alloy spring. Since it is effectively used, it can be manufactured at low cost, and since the entire air venting mechanism is housed inside the bucket, the size of the steam trap need not be changed at all. The steam trap of this type has excellent performances such as the reliable opening / closing operation of the air bleeding valve body and the rapid discharge of a large amount of residual air by the guide of the guide rod.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of a steam trap according to the present invention at a low temperature, FIG. 2 is a vertical sectional view showing a state of a steam trap according to the present invention at a high temperature, and FIG. 3 is a shape memory. A vertical sectional view around a bucket of a steam trap of the present invention using a bimetal plate instead of an alloy spring, FIG. 4 is a vertical sectional view of a general structure example of a conventional steam trap, and FIGS. FIG. 4 is a vertical sectional view of a steam trap having a conventional air venting mechanism. 1 ... Valve box, 2 ... Bucket, 5,11 ... Passage, 6 ... Weight guide rod, 9 ... Lid, 12 ... Valve seat, 13 ... Lever, 16 ... Valve body, 24 ... … Strainer, 25 …… Partition plate, 7,
26,30,32 …… Presser ring, 27 …… Bias spring, 28 …… Air vent valve body, 29 …… Shape memory alloy spring, 29 ′ …… Bimetal plate.

Claims (1)

[Scope of utility model registration request] 1. A downward bucket steam trap in which a bucket having a small hole for venting air in the ceiling is suspended in a valve box, and the valve is opened and closed by utilizing the buoyancy generated in the bucket. A guide rod also serving as a weight is fixed to the central portion, and a bias spring, an air vent valve element and a shape memory alloy spring or bimetal plate are loosely inserted in series along the guide rod, and the air vent valve element is the ceiling portion of the bucket. A steam trap characterized in that the second air vent hole further formed in the above can be opened and closed.