JPH0285581A - Air discharge device for steam pipeline and air discharge valve for steam pipeline - Google Patents

Abstract

PURPOSE:To precisely detect the air in a steam pipeline and discharge it by operating a solenoid valve and opening a discharge path when the light receiving quantity of a light receiving section receiving near infrared rays is larger than the preset value. CONSTITUTION:When the output light of near infrared rays of a light emitting element 31a passes the sample void 51 of a detecting unit 5, the component with the specific wavelength in the range of about 1.35-1.40mum is absorbed by steam. When the steam in a steam pipeline 1 is little, i.e., air is much, and the absorption quantity is little, the incident light fed to a light receiving element 32a becomes much, thus the output voltage of the light receiving circuit 32 of a controller 3 is increased, when it is made larger than the reference value, a solenoid valve driving signal is outputted from a comparing circuit 33, a solenoid valve 4 is opened by the driving output of a solenoid valve driving circuit 34, and the air in the steam pipeline 1 is automatically discharged. The existence of air is directly detected, thus the detection precision is improved, and a delicate and adequate air discharge action can be performed.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a device for discharging high-temperature air in steam piping and an air discharge valve used therein.

<Prior Art> Air remaining in steam piping and various devices connected thereto causes various problems, such as inhibiting heat conduction of steam and causing corrosion of the piping.

For this reason, conventionally, for example, an air bender equipped with a bimetal or thermowax sensor is used as a device for discharging the air present in a steam piping system, and the air is discharged by automatically opening and closing a valve. There is. This air bender is configured to detect the ambient temperature with a sensor, and if it is high temperature (about 100° C.), it is determined to be steam, and if it is low temperature, it is determined to be air, and opens and closes the valve.

<Problem to be solved by the invention> As described in Kitaki, conventional air benders do not directly detect the presence of air, but indirectly detect the presence of air from the ambient temperature, resulting in low detection accuracy and inadequate air exhaust operation. There are other problems, such as it being difficult to use and waste of thermal energy.

The present invention focuses on these problems and provides an air exhaust device for steam piping that can accurately detect and exhaust air in steam piping, and an air exhaust valve for steam piping used therein. It was done for the purpose of

<Means for Solving the Problems> In order to achieve the above-mentioned object, an air exhaust device n of the present invention includes a main body having a discharge passage communicating with a steam pipe, and a solenoid valve for opening and closing the discharge passage. , a detection unit in which a light emitting part that emits near infrared rays including an absorption spectrum band by water vapor and a light receiving part that receives this near infrared rays are disposed to face each other through a sample gap that communicates with the discharge path, and a light receiving part. and a control unit that operates the electromagnetic valve (2) to open the discharge passage when the amount of light received is greater than a predetermined value.

Further, the air exhaust valve of the present invention includes a main body equipped with an exhaust passage communicating with a steam pipe, and a solenoid valve for opening and closing the exhaust passage.
A detection unit is provided, in which a light-emitting part that emits near-infrared rays including an absorption spectrum band by water vapor and a light-receiving part that receives this near-infrared rays are arranged to face each other through a sample gap that communicates with the discharge path.

<Operation> This invention detects air by utilizing the property that the transmittance of spectral light in the wavelength range of 1.35 to 1.40 μm changes significantly due to absorption by water vapor, and when air is detected, it is discharged. It was designed to do so. In other words, the more air there is in the steam pipe, the lower the proportion of water vapor and the less absorption by water vapor. The amount of water vapor in the steam pipe can be determined based on the amount of water vapor, and the presence or absence of air can also be detected from this amount of water vapor. Since the electromagnetic valve is opened when the amount of light received by the light receiving section is larger than a predetermined value, the air in the steam pipe is properly discharged.

In addition, the main body is equipped with a discharge passage that communicates with the steam piping, and a solenoid valve that opens and closes the discharge passage is arranged so that a light-emitting part and a light-receiving part face each other through a sample gap that communicates with the discharge passage. The air exhaust valve equipped with a detection unit is easy to install in a desired opening in a steam piping system, such as steam equipment, steam traps, and other equipment or piping, and can be installed in any desired opening in a steam piping system, such as steam equipment, steam traps, and other equipment. The above-mentioned air exhaust device can be constructed by combining the above-mentioned solenoid valve with a control section that opens the exhaust passage.

<Example> Next, the illustrated embodiment will be described.

In Fig. 1, 1 indicates steam piping system equipment or piping (
(hereinafter simply referred to as steam piping), 2 is an air exhaust valve attached to steam piping 1, and 3 is a control section.

The air exhaust valve 2 is attached to the steam pipe 1 by screwing or bolting, and in this embodiment, the main body 2
The main body 21 is a screw type example in which a tapered threaded portion 22 is formed at one end of the main body 21. A discharge passage 23 is formed through the main body 21 and communicates with the inside of the steam pipe 1, and this discharge passage is formed at the other end. A solenoid valve 4 for opening and closing 23 and a detection unit 5 are attached to the side surface by screwing.

The detection unit 5 is provided with a sample gap 51 that communicates with the discharge path 23 of the main body 21, and further includes a light emitting section 52 and a light receiving section 53 arranged with this sample gap 51 in between, as shown in FIG. The structure is as follows.

That is, optical fibers 55 and 56 are housed inside the case 54 of the detection unit 5, and their ends are arranged opposite to each other on both sides of the sample cavity 51, and their respective ends are connected to the light emitting section 52 and the light receiving section. Section 53. Note that a condenser lens is provided in the light emitting section 52 and the light receiving section 53 as necessary. The other ends of the optical fibers 55 and 56 are led out to the outside for connection to the control device 3, either as they are or via an appropriate connector.

The control unit 3 includes a light emitting circuit 31 including a light emitting element 31a such as a light emitting diode or a semiconductor laser, its driving circuit, etc., and a light receiving element 32 such as a phototransistor.
A, a light receiving circuit 32 equipped with a voltage conversion circuit, etc. that converts the amount of light received by the light receiving element 32a into a voltage corresponding to the magnitude, and the output of the light receiving circuit 32 is compared with a preset reference value, and the output of the light receiving circuit 32 is determined to be larger than the reference value. A comparison circuit 33, a solenoid valve drive circuit 34, etc., which determine that the amount of air in the steam pipe 1 is large at times and output a solenoid valve drive signal are provided.

Note that the control section 3 is provided with an amplifier circuit as necessary.

Further, the optical fiber 55 is connected to the light emitting circuit 31, and the optical fiber 56 is connected to the light emitting circuit 31.
are connected to the light receiving circuit 32, respectively.

As is well known, the wavelength range of the absorption spectrum of water vapor is concentrated within the range of approximately 1.35 to 1.40 μm. Therefore, the light-emitting element 31a is one that emits near-infrared light that includes this wavelength range, and receives light. As the element 32a, one having good sensitivity to this wavelength range is used.

Note that it would be ideal if a light emitting element that emits light only in the above wavelength range could be used, but if one emission wavelength range is wider than this, it is necessary to perform accurate detection with less noise.

It is desirable to arrange in the optical path an optical filter that transmits only near-infrared rays in the above wavelength range, or an optical demultiplexer that can selectively separate and extract the near-infrared rays. Reference numeral 34 designates an optical demultiplexer for this purpose, which is inserted into the connection portion of the optical fiber 56 to the light receiving circuit 32.

This embodiment has the above-mentioned configuration, and one light emitting element 31a.
When the output light passes through the sample cavity 51, the hole 163
Components with specific wavelengths within the range of 5 to 1.40 μm are absorbed by water vapor. When there is little water vapor in the steam pipe 1 (that is, there is a lot of air) and the amount of absorption is small, more light enters the light receiving element 32a, so the output voltage of the light receiving circuit 32 increases and becomes higher than the reference value. Then, a solenoid valve drive signal is output from the comparison circuit 33, and the solenoid valve 4 is opened by the drive output of the solenoid valve drive circuit 34, and the air in the steam pipe 1 is automatically discharged.

Note that the case 54 of the detection unit 5 is normally exposed to high temperatures, and when elements such as light emitting diodes and phototransistors that are generally sensitive to heat are used, a structure using an optical fiber as in the embodiment is suitable. However, if there are elements that can withstand high temperatures, these elements may be directly arranged inside the case 54 to form the light emitting part and the light receiving part. In this case, the connection with the control section 3 will be electrical.

<Effects of the Invention> As is clear from the above-described embodiments, the air exhaust device for steam piping of the present invention detects the air in the steam piping based on the amount of near-infrared rays absorbed including the absorption spectrum band by water vapor, and The device is designed to automatically discharge air when opened, and the presence of air is detected directly rather than from an indirect physical quantity such as temperature, improving detection accuracy.
Moreover, since the electromagnetic valve can be controlled by instantly reflecting the detection information of the detection unit, it is possible to perform a finely tuned and appropriate air exhaust operation, and at the same time, it is possible to eliminate wasted energy.

Further, the air exhaust valve for steam piping of the present invention has a configuration including a solenoid valve for opening and closing the exhaust passage of one main body, and a detection unit in which a light emitting part and a light receiving part are arranged with a sample gap communicating with the exhaust passage. Because of this, it is easy to install it at the desired location in the steam piping system.

By combining it with a control section that detects the amount of light received by the light receiving section and operates the electromagnetic valve, the above-mentioned air exhaust device can be easily constructed.

[Brief explanation of drawings]

FIG. 1 is a schematic structural diagram of an embodiment of the present invention, and FIG. 2 is a schematic structural diagram of a detection unit. DESCRIPTION OF SYMBOLS 1... Steam piping, 2... Air discharge valve, 3... Control part, 4... Solenoid valve, 5... Detection unit, 21... Main body, 23... Discharge path, 31... Light emitting circuit, 31a...
- Light emitting element, 32... Light receiving circuit, 32a... Light receiving element, 33... Comparison circuit, 34... Solenoid valve drive circuit, 5
1... Sample void, 52... Light emitting section, 53... Light receiving section.

Claims (2)

[Claims] (1) Emit near-infrared rays including the absorption spectrum band of water vapor through a main body equipped with a discharge passage communicating with the steam piping, a solenoid valve that opens and closes the discharge passage, and a sample cavity communicating with the discharge passage. a detection unit in which a light-emitting part that receives the near-infrared rays and a light-receiving part that receives the near-infrared rays are arranged to face each other, and a control part that operates the solenoid valve to open the discharge passage when the amount of light received by the light-receiving part is larger than a predetermined value; An air exhaust device for steam piping, characterized by comprising: (2) The main body is equipped with a discharge passage that communicates with the steam piping, and a solenoid valve that opens and closes the discharge passage and emits near-infrared rays that include the absorption spectrum band of water vapor through a sample cavity that communicates with the discharge passage. An air exhaust valve for steam piping, characterized in that it is provided with a detection unit in which a light emitting part that emits light and a light receiving part that receives this near infrared rays are placed facing each other.