JP2559275B2 - Steam trap and condensate discharge device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a steam trap capable of detecting the condensate water level, pressure and temperature in a receiver tank, and a condensate discharge device using the steam trap.

<Prior Art> Most of the conventional steam traps operate by individually detecting the state of the condensate water level and temperature, and the available information is limited. Therefore, it is usually designed so that the desired performance can be exhibited during steady operation. On the other hand, many steam-using devices and apparatuses using these steam traps have advanced functions with advanced energy saving.

<Problems to be Solved by the Invention> As described above, since the information obtained by a general steam trap is limited, it is possible to exhibit its performance when an unexpected situation occurs or in the initial stage of ventilation. Have difficulty. In addition, even if air locking or steam locking occurs in the trap, the state of the device cannot be grasped by the device itself, and it is almost impossible to eliminate these abnormalities. There are many things that cannot be positively resolved.

Therefore, the performance of the steam trap cannot keep up with the performance of the highly functional steam device, and it often takes time to resolve abnormal conditions and recover to a steady state. In some cases, it adversely affects the performance of the device.

The present invention has been made in view of these problems, and an object thereof is to improve the performance of a steam trap and a condensate discharge device using the steam trap with a relatively simple structure.

<Means for Solving the Problems> In order to achieve the above-mentioned object, the steam trap of the present invention has a water level detecting means for detecting the water level of condensate in the receiver tank and a pressure for detecting the pressure in the receiver tank. It is provided with a detection means, a temperature detection means for detecting the temperature inside the receiver tank, and a discharge valve which is opened and closed according to the combination of the detection results by these detection means.

The water level detecting means can be composed of a plurality of optical sensor units and electrostatic capacitance probes arranged at different heights.

Further, the condensate discharge device of the present invention detects the temperature outside the steam trap in addition to the three types of information detected by the steam trap, and the temperature information and the detection means of the steam trap detect the temperature. The exhaust valve of the steam trap is controlled to open and close according to the combination with the three types of information.

<Operation> According to the steam trap of the present invention, it is possible to obtain three types of information of the condensate water level, pressure and temperature in the receiver tank at the same time, and the amount of information obtained increases. The discharge valve is opened and closed.

Further, the situation can be judged more appropriately by using the temperature information outside the steam trap.

First Example Next, the illustrated first example will be described. FIG. 1 is a conceptual diagram showing the overall structure of the steam trap and the condensate discharge device, FIG. 2 is a front view of the inside of the water level detection unit of the steam trap, FIG. 3 is a plan view of the steam trap, and FIG. FIG. 5 is a side view of the same water level detector, and FIG. 6 is an explanatory view of the configuration and operation of the optical sensor unit.

In the figure, 1 is an inlet, 2 is an outlet, 3 is a receiver tank, 4 is a motor valve, and these are no different from known steam traps. Reference numeral 5 is a water level detector, 6 is a pressure sensor, and 7 is a temperature sensor, which are provided by the present invention.

The water level detection unit 5 is a water level meter incorporating an optical sensor unit. In FIG. 2, 51 is a glass tube similar to that used in the conventional water level gauge, and the upper and lower ends thereof are respectively supported by the support pipe parts 52 by the receiver tank 3
Is in communication with. Reference numeral 53 denotes a detection section cover formed of two cover halves 53a fixed so as to sandwich the glass tube 51, and 54 denotes an optical sensor unit formed of a pair of light projecting section 54a and light receiving section 54b, which are formed on the cover half 53a. Recess 5
A plurality of sets having different heights are provided inside the detection unit cover 53 by utilizing 3b. At least two sets of these optical sensor units 54 are required so that the minimum water level and the maximum water level can be detected, and three sets are provided in this embodiment. 53c is a peep hole. In this embodiment, the light projecting portion 54a and the light receiving portion 54b are the input / output ends of the optical fiber 55, and are located slightly off the center of the glass tube 51, as shown in FIG. They are arranged in pairs on a straight line that crosses. Therefore, when there is condensate in the glass tube 51, the light beam from the light projecting section 54a reaches the light receiving section 54b as shown by the solid line in the figure, but when the glass tube 51 is a gas such as steam or air. In this case, the light ray is totally reflected by the glass surface as shown by the broken line and the light beam does not reach the light receiving portion 54b, whereby the presence or absence of condensate is detected. The optical fiber 55 is led out from a hole in the lower portion of the detection unit cover 53 and is connected to a light emitting element 56a and a light receiving element 56b of a light receiving and emitting circuit 56 provided in the control unit 8 which will be described later.

Further, as the pressure sensor 6 and the temperature sensor 7, a pressure pickup, a thermocouple or the like which has been conventionally used for a steam trap is appropriately used, and the T-joint 57 is provided at a position higher than that at the top of the optical sensor unit 54. Is installed through.

Reference numeral 8 denotes a control unit, such as an input port 81, a CPU 82 for performing various calculations, and a ROM 8 in which a control program is stored.
3. A microcomputer having a RAM 84 for appropriately storing calculation results and the like, an output port 85 and the like is a main part, and the light emitting / receiving circuit 56 described above is further provided. And this control unit 8
The detection output of each optical sensor unit 54, the pressure sensor 6 and the temperature sensor 7 is input to the input port 81, and the output port
The driver circuit 86 is operated by the drive signal output from 85, and the motor valve 4 is driven to open and close the discharge valve 4a.

That is, since the vapor has a property that the saturation temperature changes depending on the pressure, if the data of the pressure and temperature in the receiver tank 3 detected by the pressure sensor 6 and the temperature sensor 7 are compared, the presence or absence of the vapor can be easily detected. Can be determined. Therefore,
By combining this with data on the water level by the optical sensor unit 54, it is possible to determine whether it is air or condensate, and determine various conditions from the combination of the condensate water level, pressure and temperature in the receiver tank 3. Then, the discharge valve 4a of the motor valve 4 is controlled to be opened and closed according to the conditions. The drive control of these motor valves 4 can be easily executed by pre-programming judgment criteria and control contents according to various expected situations as described later.

It should be noted that the control unit 8 does not necessarily have to be a microcomputer, and control is somewhat troublesome, but it may be configured by a general discrete circuit.

This embodiment has the configuration as described above, and the following control is performed, for example.

First, in the case of the air in the initial stage of ventilation, the temperature is low and the pressure is very low, so that it can be easily determined.

Further, since the temperature of the initial condensate is low and the water level is detected by the optical sensor unit 54, this can also be easily discriminated, and a valve opening signal is sent to the motor valve 4 to send the discharge valve 4a.
Is opened.

After a certain amount of time has passed after the start of ventilation, and the temperature detected by the temperature sensor 7 enters the vapor saturation temperature of the pressure detected by the pressure sensor 6 or within the initially set temperature range,
Since the processing is performed only by the detection signal of the optical sensor unit 54, the discharge valve 4a is opened / closed according to the detected condensate water level.

Next, when air locking occurs, the partial pressure between air and steam acts as a total pressure, so that the saturation temperature decreases by the amount that the steam pressure decreases. Therefore, if the value is lower than the initial set value, it can be determined that air locking or air mixing, so a valve opening signal is sent to the motor valve 4 as necessary.

The above is an example of performing control using three types of information such as the condensate water level in the receiver tank 3 and the pressure and temperature in the receiver tank 3, but outside the steam trap, for example, on the upstream side or the downstream side. It is possible to make a more appropriate situation judgment by using the temperature information of.

In FIG. 1, reference numeral 9 is a temperature sensor provided near the inlet 1 for this purpose, and a detection signal thereof is also input to the control unit 8. Due to this, for example, the temperature between the steam device and the inside of the steam trap reverses, and there is condensate on the upstream side. become able to. Furthermore, when the upstream device temperature drops due to a sudden load, etc., it is possible to judge in advance the increase in condensate, and it is possible to forcibly open the discharge valve 4a to cope with the increase in condensate. It will be.

Second Example Next, a second example using a capacitance probe as the water level detecting means will be described.

As described above, in the first embodiment, the optical sensor unit 54 is used for the water level detection unit 5, but there is a possibility that the detection failure may occur due to dirt on the glass tube 51 or the like. Further, although the optical fiber 55 is used for the connection, the optical fiber itself may be melted when the atmospheric temperature rises or the hot pipe is touched. The second embodiment eliminates the malfunction due to such a cause, FIG. 7 is a conceptual diagram showing the entire configuration of the steam trap and the condensate discharge device, and FIG. 8 is a capacitance probe. It is a figure. The same parts as those in the first embodiment are designated by the same reference numerals, and different points will be described below.

In FIG. 7, reference numeral 58 denotes an electrostatic capacitance probe, and three electrostatic capacitance probes 58 are directly attached to the side wall of the main body of the receiver tank 3 so that the minimum water level, the maximum water level and the intermediate water level can be detected. In this embodiment, the glass tube 51 as in the first embodiment is unnecessary. As shown in FIG. 8, the capacitance probe 58 has a well-known structure including a center electrode 58b and a cylindrical outer electrode 58c which are insulated from each other by an insulating base 58a. For example, the center electrode 58b is made of copper,
The outer electrode 58c is made of stainless steel. The surface of at least one of the electrodes is covered with an insulating film, and it is detected that the capacitance between the electrodes changes according to the dielectric constant of the substance flowing between the electrodes, and this change is detected by, for example, the probe unit 59a. The capacitance meter 59b is configured to perform amplification detection. Reference numeral 59 in FIG. 7 is an amplifier circuit having such a function of amplification detection. The presence / absence of condensate is detected by utilizing the fact that the water content changes greatly depending on the presence / absence of water.

This embodiment is configured as described above, and detects the water level in the receiver tank 3 from the output of each capacitance probe 58, and according to the result and the pressure and temperature in the receiver tank 3, Similarly, various operations are performed.

Here, for example, a conduction probe may be used as the electrical water level detecting means, but there is a possibility that the conduction probe may conduct electricity even if water droplets adhere to it and cause a malfunction. On the other hand, in the case of this embodiment, by setting the capacitance change of the capacitance probe 58 required for detection to be large to some extent, it is possible to eliminate the influence of a small amount of water such as water droplets and to ensure the reliability. The presence or absence of inflow can be detected. Further, since the dielectric constant of the inflow substance changes due to a change in the temperature of the inflow substance itself or the inclusion of foreign matter, it is possible to detect an abnormal rise in the water temperature in the receiver tank 3 or the inclusion of foreign matter relatively easily.

Therefore, according to the steam trap of this embodiment, unlike the case of the optical sensor unit, the malfunction due to the dirt of the glass tube of the detection part or the damage of the optical fiber itself is eliminated, and the water level can be detected more reliably. Of.

<Effects of the Invention> As is apparent from the above-described embodiments, the steam trap of the present invention is provided with detection means for detecting the water level of the condensate in the receiver tank and the pressure and temperature in the receiver tank, respectively. The discharge valve is opened and closed according to the combination of the detection results by these, and as the water level detection means, a plurality of optical sensor units and electrostatic capacitance probes arranged at different heights are used. Is.

Therefore, it is possible to simultaneously obtain three types of information on the condensate water level, pressure, and temperature in the receiver tank.
A steam trap capable of performing control suitable for a highly functionalized steam device can be obtained with a relatively simple configuration. Further, in the case where the optical sensor unit is used as the water level detecting means, it is not necessary to introduce electric wiring into the steam trap, which simplifies the structure and improves safety. Further, when the capacitance probe is used as the water level detecting means, reliability is improved without being affected by dirt on the glass tube, damage to the optical fiber itself, adhesion of water droplets or the like on the probe.

In addition, the condensate discharge device of the present invention uses the steam trap described above, utilizes the external temperature information in addition to the three types of detected information, and controls the opening and closing of the discharge valve according to the combination of these. It was done.

Therefore, the judgment is made based on the three types of information of the condensate water level, pressure, and temperature in the receiver tank of the steam trap, and the temperature information outside the steam trap is also used as necessary, so the situation judgment is appropriate. Thus, a high-performance steam trap and condensate discharge device can be obtained without deteriorating the performance of a highly functionalized steam device.

[Brief description of drawings]

FIG. 1 is a conceptual diagram showing the overall configuration of a steam trap and a condensate discharge device according to a first embodiment of the present invention, FIG. 2 is a front view of the inside of a water level detecting section of the steam trap, and FIG. A plan view of the steam trap, FIG. 4 is a front sectional view of the steam trap,
FIG. 5 is a side view of the same water level detection unit, FIG. 6 is an explanatory view of the configuration and operation of the optical sensor unit, and FIG. 7 is an overall configuration of the steam trap and condensate discharge device of the second embodiment. FIG. 8 is a conceptual diagram showing the capacitance probe of the same embodiment. 3 ... Receiver tank, 4 ... Motor valve, 4a ...
… Discharge valve, 5 …… Water level detector, 6 …… Pressure sensor, 7,9
...... Temperature sensor, 8 ...... Control section, 51 ...... Glass tube, 54 ...... Optical sensor unit, 54a ...... Light projecting section, 54b ......
Light receiving part, 58 ... Capacitance probe, 59 ... Amplifying circuit, 82
……CPU.

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Koji Mori 2-11 Kinnohonmachi, Hirakata-shi, Osaka (72) Inventor Mutsuji Muramoto 2-3-1 Tagawakita, Yodogawa-ku, Osaka-shi, Unison Co., Ltd. (56) References Japanese Patent Publication Sho 58-3155 (JP, B2)

Claims (4)

(57) [Claims] 1. A water level detecting means for detecting a water level of condensate in a receiver tank, a pressure detecting means for detecting a pressure in the receiver tank, a temperature detecting means for detecting a temperature in the receiver tank, and these detection means. A steam trap, comprising: a discharge valve that opens and closes according to a combination of detection results by the means. 2. The steam trap according to claim 1, wherein the water level detecting means is composed of a plurality of optical sensor units arranged at different heights. 3. The steam trap according to claim 1, wherein the water level detecting means is composed of a plurality of capacitance probes arranged at different heights. 4. The steam trap according to claim 1, 2 or 3 is used, and in addition to the three types of information detected by each detecting means, the temperature outside the steam trap is detected to judge these information. A condensate discharge device characterized by controlling the opening and closing of the discharge valve of the steam trap according to the combination.