JPH0366557B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention is directed to the use of steam reduced to below atmospheric pressure.
This relates to a vacuum trap used as a heating source at temperatures of about 100 to 60°C.

[Conventional technology]

Recently, industrial applications often require heating at temperatures below 100°C, and steam has come to be used as a heat source instead of hot water, which has traditionally been used. The main reason for this is that heating with steam has characteristics such as a large amount of heat transfer, a large heat transfer coefficient, and the ability to heat at a uniform temperature.

Since this type of heating device is used by reducing the pressure of steam to below atmospheric pressure, it has a configuration as shown in FIG. 2. In the figure, the steam sent from steam source 1 is 1 to 2 kg/cm ² (gauge pressure).
This steam is transferred to the heat-using section 3 by the pressure reducing valve 2.
The pressure is reduced according to the required temperature, for example, when the required temperature is
If the temperature is 80℃, the pressure will be reduced to 380Torr. A vacuum pump 6 is connected downstream via a pipe line in which a steam trap 4 and a bypass valve 5 are connected in parallel so as to maintain a negative pressure after the pressure reducing valve 2.
The steam trap 4 is the same as that used in conventional steam systems at pressures higher than atmospheric pressure, and is not specially manufactured for vacuum use. Therefore, although it has a condensate discharge function, it does not have a function to eliminate air obstruction. The bypass valve 5 is used while being set to a constant opening degree. This is necessary to maintain the pressure of the steam in the heat-using section 3, that is, the pressure on the primary side of the steam trap, at a predetermined pressure below atmospheric pressure, and is also necessary to eliminate air bar binding.

[Problem that the invention seeks to solve]

In the above-mentioned heating device using reduced pressure steam, since the bypass valve 5 is always open at a constant opening degree, there is a problem in that the steam loss is large.

An object of the present invention is to provide a vacuum steam trap that can reduce steam loss and omit a bypass circuit including a bypass valve 5.

[Means for solving problems]

The means according to the invention operates in a vacuum trap whose secondary side is connected to a vacuum system, in addition to the condensate discharge section, by operating between the primary side and the secondary side based on the pressure difference between the two sides. It is characterized by being equipped with a pressure regulating valve that discharges gas to the secondary side.

[Effect]

According to the above means, since the pressure regulating valve operates to maintain a constant differential pressure on the primary side with respect to a predetermined secondary side pressure, when the pressure on the primary side increases, that is, the degree of vacuum on the primary side decreases. The pressure regulating valve then opens, restores the vacuum, and then closes. Therefore,
The gas on the primary side is discharged as necessary, and the primary side and the secondary side are not always in communication. Also, since this pressure regulating valve discharges gas, it eliminates air bar binding. In addition,
The condensate discharge part may be the same as a conventional one, and its formation may be either a float type, a bucket type, or the like. In short, it is sufficient if only the condensate can be discharged to the secondary side.

〔Example〕

One embodiment of the present invention will be explained using FIG. In the figure, 10 indicates the entire vacuum trap, 11 an inlet with a primary connection, 12 an outlet with a secondary connection, 13 a condensate discharge, 1
4 is a pressure regulating valve.

The condensate discharge part 13 is provided with a condensate reservoir chamber 15 between the inlet 11 and the outlet 12, and a condensate passage 16 that communicates the lower part of the condensate reservoir chamber 15 with the outlet 12. 16 is provided with a valve hole 17 that opens into the condensate reservoir chamber 15, and a spherical float valve body 18 that opens and closes in the condensate reservoir chamber 15 with respect to the valve hole 17.
It has been established. In the figure, 19 is a float cover.

The pressure regulating valve 14 is provided with a gas passage 20 that communicates the upper space of the condensate reservoir chamber 15 with the outlet 12, and a valve seat member 21, a disc valve 22, a pressure setting spring 23, and an adjusting screw are provided in the middle of the gas passage 20. 24 etc. is installed. The disc valve 22 has a condensate reservoir chamber 15 on the lower surface in the figure, that is, the valve seat 25 is in contact with the valve seat 25 from above so as to receive the pressure on the primary side, and the valve hole 2 is in contact with the valve seat 25 from above.
6 is closed, and is pressed from above by a spring 23, and pressure from the gas passage 20, that is, the secondary side, acts on it. Therefore, when the acting force due to the pressure on the primary side acting on the disc valve 22 becomes larger than the acting force due to the secondary side pressure plus the acting force due to the spring 23, the disk valve 22 is displaced upward and opens, and when it becomes smaller, the valve opens. Close the valve. Spring 23
The force acting on the disc valve can be adjusted by changing the degree of compression of the spring 23 by rotating the adjustment screw 24 and moving it forward and backward. In the figure, 27 is a mounting member for mounting an adjustment screw through the trap body, 28 and 29 are O-rings, 30 is a lock nut, and 31 is a protective cap nut.

The vacuum trap 10 constructed in this manner is used in place of the steam trap 4 and bypass valve 5 of a heating device using reduced pressure steam as shown in FIG. In its use, condensate flowing into the condensate reservoir chamber 15 from the inlet 11 is sent out through the valve hole 17, the condensate passage 16, and the outlet 12 by the vertical movement of the float valve body 18 of the condensate discharge section 13.

Furthermore, when the primary side pressure exceeds a predetermined secondary side pressure or higher than the set pressure set by the spring 23, the disc valve 22 of the pressure regulating valve 14 rises and opens. Gas is delivered through the inlet 11, the upper space of the condensate reservoir 15, the valve hole 26, the gas passage 20, and the outlet 12. When air is mixed in the primary side, it is sent to the secondary side along with steam.
When the pressure on the primary side drops to the set value, the pressure regulating valve 14 closes.

Therefore, in addition to the original condensate discharge function, the vacuum trap 10 has a pressure adjustment function that restricts the primary side pressure from rising above a set value by gas discharge, so a separate bypass valve is required. do not need. Further, since the pressure regulating valve 14 is opened as necessary, there is little loss of steam.

〔Effect of the invention〕

According to the present invention, it is possible to provide a vacuum trap that can be used alone in place of a conventional steam trap and bypass valve, thereby simplifying piping. Additionally, since the vacuum trap does not have a pressure regulating valve that is always open, steam loss is significantly reduced compared to when a conventional bypass valve is used. It also eliminates air bar binding.

[Brief explanation of drawings]

Fig. 1 shows one embodiment of the present invention, a is a longitudinal sectional side view showing the entire vacuum trap, b is an enlarged sectional view of the main part of a, and Fig. 2 is a schematic diagram of a conventional heating device using reduced pressure steam. FIG. 10... Vacuum trap, 11... Inlet (primary side), 12... Outlet (secondary side), 13... Condensate discharge section, 14... Pressure adjustment valve.

Claims (1)

[Claims] 1 In a vacuum trap whose secondary side is connected to a vacuum system, the trap operates based on the differential pressure between the primary side and the secondary side, in addition to the condensate discharge part, to transfer the primary gas to the secondary side. A vacuum trap characterized by being equipped with a pressure regulating valve for discharging air into the air.