JP2010249610A - Constant pressure mechanism - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inexpensive constant pressure mechanism for a fluid, supplying the fluid within a prescribed pressure fluctuation by using a simple structure. <P>SOLUTION: The mechanism is provided with: a preliminary heating container 23 forming a sealed space in its hollow part by using a heat conductor block 22, a first end plate 20 and a second end plate 24; and a resistance tube 28 configured so as to keep one end fixed to a tube inlet attaching part 26 disposed at the second end plate 24, to pass through the outside of the preliminary heating container 23 from the tube inlet attaching part 26, to penetrate a tube support part 27 of the second end plate 24, to be introduced into the preliminary heating container 23 and to keep the other end fixed to a tube outlet attaching part 29 disposed at the first end plate 20. The fluid is injected in the preliminary heating container 23 from an inlet port 25, and after being preliminarily heated by the preliminary heating container 23, it is sent from the tube inlet attaching part 26 into the resistance tube 28 and sent out of the tube outlet attaching part 29 to the outside of the preliminary heating container 23, so that the fluid is controlled at the constant pressure. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a fluid constant pressure mechanism that can be used in a water quality analyzer or the like.

In the conductivity type TOC meter, the difference between the conductivity of the sample water measured in the collected state and the conductivity measured after irradiating the sample water with UV (ultraviolet rays) to decompose the organic matter, The amount of CO ₂ related to the pollutant is determined, and the TOC value contained in the sample water is calculated. When supplying sample water to this conductivity type TOC meter, generally, a method of reducing the fluctuation in the pressure of the sample water and keeping the flow rate of the sample water substantially constant by a regulator having a pressure reducing valve is taken. (See Patent Document 1).

  However, in the method described in Patent Document 1, the pressure / flow rate of the sample water is not controlled in response to a change in the sample water pressure caused by a change in the ambient temperature of the TOC meter. Only the flow rate can be set. On the other hand, a method is known in which a resistance tube is used without using a regulator or an orifice, and the flow rate or pressure is controlled using the pressure loss of the fluid flowing in the tube. When the ambient temperature and the fluid temperature change, the inner diameter of the resistance tube and the viscous resistance of the fluid change. Therefore, it is necessary to adjust the temperature of the resistance tube.

JP 2004-177164 A

  However, in the conventional method, since the flow rate of water in the resistance tube is high, even if the resistance tube is brought into contact with the temperature-controlled heat conductor block, the temperature of the water passing through the resistance tube reaches the temperature of the heat conductor block. It will pass through the resistance tube before it reaches enough, and it is difficult to control the pressure and flow rate. On the other hand, there is a method of controlling the sample water flow rate using a mass flow controller, but the apparatus becomes expensive and it is difficult to control the fluid to a constant pressure.

  In view of the above problems, an object of the present invention is to provide an inexpensive fluid constant pressure mechanism that can supply a fluid within a predetermined pressure fluctuation with a simple structure.

  Aspects of the present invention include: (a) a first end plate having a hollow heat conductor block and an inlet port, which is fixed to one end of the hollow portion of the heat conductor block, and the other end of the hollow portion. A preheating container having a second end plate fixed to the part, a heat conductor block, a first and a second end plate, and forming a sealed space in the hollow part, and (b) a heat conductor block A heater for adjusting the heating temperature, and (c) one end fixed to a tube inlet mounting portion provided on the second end plate, and the second inlet via the outside of the preheating container from the tube inlet mounting portion. A constant fluid pressure comprising a resistance tube penetrating the tube support portion of the end plate, introduced into the preheating container, and having the other end portion fixed to the tube outlet mounting portion provided in the first end plate Regarding the mechanism. That is, in the constant pressure mechanism according to the aspect of the present invention, the fluid is injected from the inlet port into the preheating container, preheated in the preheating container, and then sent from the tube inlet mounting portion to the resistance tube. The fluid is controlled to a constant pressure by being sent out of the preheating container from the tube outlet mounting portion.

  According to the present invention, it is possible to provide an inexpensive fluid constant pressure mechanism that can supply a fluid within a predetermined pressure fluctuation with a simple structure.

It is a mimetic diagram showing a continuous water quality analysis system which has a constant pressure mechanism concerning an embodiment of the invention. It is the figure which compared the ambient temperature dependence of the sample water in the resistance tube exit at the time of using the constant pressure mechanism which concerns on the Example of this invention with the comparative example.

  Next, embodiments of the present invention will be described with reference to the drawings. The drawings are schematic, and the same reference numerals are given to the same parts. The following embodiments of the present invention exemplify apparatuses and methods for embodying the technical idea of the present invention. The technical idea of the present invention is based on the material and shape of component parts. However, the structure and arrangement are not limited to the following. The technical idea of the present invention can be variously modified within the technical scope described in the claims.

As shown in FIG. 1, the TOC measurement system having the constant pressure mechanism according to the embodiment of the present invention makes the pressure of the sample introduction system 1 and the fluid (sample water) introduced from the sample introduction system 1 constant. A constant pressure mechanism 2 and a TOC meter 3 that measures the amount of TOC of a fluid whose pressure is made constant by the constant pressure mechanism 2 are provided. In FIG. 1, the pressure sensor 4 is provided in the pipe 15 e that connects the constant pressure mechanism 2 and the TOC meter 3, but the pressure sensor 4 has the effect of the constant pressure mechanism 2 according to the embodiment of the present invention. It is used for demonstration, and can be omitted if the purpose is an inexpensive system.

  The sample introduction system 1 includes a sample water collection duct 11, a pipe 15a having one end attached through the wall of the sample water collection duct 11, and the other end of the pipe 15a inserted from the top to the inside. A fixed drain pot 12, a pipe 15 b having one end connected to the top of the drain pot 12, a suction airtight container 13 in which the other end of the pipe 15 b is inserted and fixed from the top to the inside, and a suction A pipe 15c having one end connected to the upper portion of the airtight container 13, a suction motor 14 having a suction side connected to the other end of the pipe 15c, and one end connected to the discharge side of the suction motor 14. And a pipe 15d.

   The constant pressure mechanism 2 is provided in contact with the outer surface of the cylindrical heat conductor block 22, the heat conductor block 22, the cylindrical heater 21 that heats the heat conductor block 22, and the heat conductor block 22. It has the resistance tube 28 provided in the hollow part inside. The heat conductor block 22 is preferably made of a material having high thermal conductivity such as aluminum.

  The first end portion (left end portion) of the hollow portion of the heat conductor block 22 has an inlet port 25 having a convex shape toward the outside and a tube outlet mounting portion 29 having a convex shape toward the outside. The end plate 20 is provided so as to close the hollow portion of the heat conductor block 22. On the other hand, at the other end (right end) of the hollow portion of the heat conductor block 22, a tube inlet mounting portion 26 having a convex shape toward the outside and a tube support portion 27 having a convex shape toward the outside are provided. A second end plate 24 is provided so as to close the hollow portion of the heat conductor block 22. The first end plate 20 and the second end plate 24 form a sealed space that sandwiches the hollow portion from both sides, and a preheating container 23 that stores and heats sample water is formed.

  As shown in FIG. 1, one end of the pipe 15 d is connected to an inlet port 25 so that sample water as a fluid can be introduced into the preheating vessel 23 through the inlet port 25. One end of the resistance tube 28 is fixed to the tube inlet mounting portion 26 from the outer side (right side in FIG. 1) to the inner side (left side in FIG. 1). The resistance tube 28 supports the tube again from the tube inlet mounting portion 26 through the outside of the preheating vessel 23 (on the right side of the second end plate 24 in FIG. 1) toward the second end plate 24 again. 1 enters the inside of the preheating vessel 23 through the portion 27, proceeds from the right side to the left side through the inside of the preheating vessel 23, penetrates the tube outlet mounting portion 29, and is located outside the preheating vessel 23 (in FIG. It appears on the left side of the end plate 20. The other end of the resistance tube 28 that passes through the tube outlet attachment portion 29 and comes out of the preheating container 23 is connected to the pressure sensor 4. The length of the resistance tube 28 can be adjusted by making the part accommodated in the preheating container 23 into a three-dimensional shape such as a spiral.

  One end of a pipe 15 e connected to the TOC meter 3 is connected to the outlet of the pressure sensor 4. The TOC meter 3 is connected to the other end of the pipe 15e and is connected to the first conductivity meter 31 for measuring the conductivity before decomposing the organic matter, and the UV for decomposing the organic matter is connected to the first conductivity meter 31. An oxidative decomposition apparatus 32 and a second conductivity meter 33 that is connected to the UV oxidative decomposition apparatus 32 and measures the electrical conductivity after decomposing organic substances are provided.

  In the configuration shown in FIG. 1, sample water (fluid) is introduced from the duct 11 into the drain pot 12 through the pipe 15a and is stored in the suction airtight container 13 through the pipe 15b. The sample water stored in the suction airtight container 13 is sucked by the suction motor 14 from the suction airtight container 13 through the pipe 15c, and is discharged to the pipe 15d by a preset discharge amount of the suction motor 14, and the sample water inlet is convex. The inside of the preheating container 23 enters from the part 25. The sample water (fluid) is supplied to the resistance tube 28 from the tube inlet mounting portion 26 after the preheating container 23 is filled and heated to a predetermined temperature.

  Here, the resistance tube 28 preferably has, for example, an inner diameter of about 0.25 to 0.75 mmφ and a length of about 500 to 1000 mm. In the case of such an inner diameter and length, the discharge amount of the suction motor 14 is also considered. However, the sample water flow rate can be set from the piping resistance of the resistance tube 28 to a value in the range of about 10 to 15 mL / min, for example. The temperature of the sample water filled in the preheating container 23 is controlled by adjusting the temperature of the heat conductor block 22 by the heater 21. At that time, the temperature of the sample water is set by providing a temperature sensor near the sample water inside the preheating container 23 of the end plate 24 by being embedded in the end plate 24 or penetrating the end plate 24. Control can be performed directly, and more responsive temperature control can be performed. The resistance tube 28 accommodated in the preheating container 23 is immersed in the sample water filled in the preheating container 23 at a low flow rate. Since the sample water passing through the resistance tube 28 is filled in the preheating vessel 23 at a low flow rate before being introduced into the resistance tube 28, the sample water is easily reserved at the same temperature as the heat conductor block 22. Heated.

  Considering the efficiency of the preheating, it is preferable that the cross sectional area perpendicular to the flow velocity direction of the preheating container 23 is designed to be 30 times or more larger than the cross sectional area of the resistance tube 28. If all the sample water filled with the preheating container 23 is preheated to a predetermined temperature in a state that is 30 times or more slower than the flow rate in the resistance tube 28, then the sample water is introduced into the resistance tube 28. The temperature of the sample water passing through the inside of the resistance tube 28 is kept constant even when the flow rate is increased. As the cross-sectional area perpendicular to the flow velocity direction of the preheating vessel 23 is larger by 30 times or more than the cross-sectional area of the resistance tube 28, the heating efficiency is improved. However, in practice, if the size of the preheating vessel 23 is increased, The cross-sectional area perpendicular to the flow velocity direction of the preheating vessel 23 may be about 10000 times the cross-sectional area of the resistance tube 28.

The sample water that has passed through the resistance tube 28 exits from the tube outlet mounting portion 29 to the outside of the preheating vessel 23, is supplied to the TOC meter 3 through the pipe 15e, and the conductivity before and after the organic matter is decomposed by the UV oxidative decomposition apparatus 32. Is measured by the first conductivity meter 31 and the second conductivity meter 33, the CO ₂ amount related to the organic pollutant in the sample water is determined from the difference therebetween, and the TOC amount is calculated.

  According to the constant pressure mechanism according to the embodiment of the present invention, a simple device as shown in FIG. 1 is used without using a fluid pressure and flow rate control device such as a regulator, a pressure gauge, an orifice, and a mass flow controller. By using the configuration, it is possible to realize an inexpensive fluid constant pressure mechanism in which the fluid temperature and the resistance tube 28 do not change even when the ambient temperature changes. For this reason, according to the constant pressure mechanism according to the embodiment of the present invention, since the inner diameter of the resistance tube 28 and the viscous resistance of the fluid can be prevented from changing, a fluid having a constant pressure is fed into an external device such as the TOC meter 3. be able to.

(Example)
Using the constant pressure mechanism 100 illustrated in FIG. 1, the ambient temperature is set to 7 ° C., 25 ° C., and 43 ° C., respectively, and the heat conductor block 22 using aluminum as the material of the heat conductor is 50 ± 2. The temperature was adjusted to 5 ° C., sample water was injected as a fluid into the preheating container 23, and the sample water was preheated. The sample water that has entered the resistance tube 28 from the tube inlet mounting portion 26 passes through the resistance tube 28 accommodated in the preheating container 23 from the tube support portion 27, and exits from the tube outlet mounting portion 29 to the outside of the preheating container 23. Then, the water pressure of the sample was measured by the pressure sensor 4 connected to the end of the resistance tube 28 at the outlet. Here, the resistance tube 28 made of polytetrafluoroethylene (PTFE) having an inner diameter of 0.5 mmφ and a length of 750 mm was used. At this time, the discharge amount of the suction motor 4 was set so that the initial value of the sample water flow rate was 12.5 ml / min.

(Comparative example)
Ambient temperatures were set to 7 ° C., 25 ° C., and 43 ° C., respectively, and sample water as a fluid was directly fed into a PTFE resistance tube brought into contact with an aluminum block that had been adjusted to 50 ± 2.5 ° C. The sample water pressure at the sample water outlet of the resistance tube was measured by a pressure sensor. Here, the inner diameter and length of the resistance tube, and the sample water flow rate were the same as in the example.

Table 1 shows sample water pressure measurement values at the sample water outlet of the resistance tube 28 measured by the pressure sensor 4 when the ambient temperature is 7 ° C, 25 ° C, and 43 ° C. The sample water pressure measurement was normalized with the sample water pressure measurement at an ambient temperature of 25 ° C. being 100%.

  FIG. 2 illustrates the results of Table 1. From Table 1 and FIG. 2, when the sample water of the example was preheated to 50 ° C. and then sent to the resistance tube 28 adjusted to 50 ° C., the sample water pressure at the outlet of the resistance tube 28 was When the ambient temperature is 7 ° C., the sample water pressure is almost 99.9 to 10.4% with respect to the sample water pressure at 25 ° C. Even if the ambient temperature reaches 43 ° C., the sample water pressure is 103.3. It is clear that the fluctuation is as small as 103.4% and is kept within the specification range of ± 5%.

  On the other hand, when the sample water in the comparative example which has not been preheated is directly sent to the resistance tube 28 which is brought into contact with the heat conductor block 22 and is adjusted to 50 ° C., the ambient temperature becomes 7 ° C. or 43 ° C. The sample water pressure at the outlet of the resistance tube 28 fluctuates 10% or more with respect to the sample water pressure at the ambient temperature of 25 ° C.

  In the embodiment, even if the ambient temperature fluctuates at a temperature lower than 50 ° C. by simply feeding the sample water into the preheating vessel 23 adjusted to 50 ± 2.5 ° C., the pressure fluctuation at the outlet of the resistance tube 28 is It can be seen that it is sufficiently small and can be kept within the specification range of ± 5%.

(Other embodiments)
As described above, the embodiments of the present invention have been described. However, the description and the drawings, which form a part of this disclosure, do not limit the present invention. From this disclosure, various alternative embodiments, examples and operational techniques will be apparent to those skilled in the art.

   For example, in the above embodiment, a part of the resistance tube 28 protrudes outside the preheating container 23, but the entire constant pressure mechanism 2 includes the resistance tube 28 exposed outside the preheating container 23. Since the temperature fluctuation of the resistance tube 28 can be cut off from the surrounding temperature fluctuation by covering with a heat insulating material, the pressure fluctuation of the fluid can be further reduced.

  In addition, as is clear from the above description, the constant pressure mechanism described in the above embodiment has a constant flow rate using the resistance tube 28 without using a fluid flow rate control device such as a regulator or a mass flow controller. Since the fluid temperature and the resistance tube 28 do not change even if the ambient temperature changes, the inner diameter of the resistance tube 28 and the viscous resistance of the fluid do not change. Obviously, it also functions as a mechanism.

  Therefore, the technical scope of the present invention is determined only by the invention specifying matters according to the scope of claims reasonable from the above description.

  The constant pressure mechanism of the present invention can be adopted as a constant pressure mechanism of water such as drainage, environmental water, tap water, sewage, pure water, various types of water, which is one of fluids, and a water quality analyzer such as a TOC meter. If the constant pressure mechanism of the present invention is used in the above field, sample water at a predetermined flow rate can be supplied within a predetermined pressure fluctuation, so that highly accurate water quality analysis is possible.

DESCRIPTION OF SYMBOLS 1 ... Sample water introduction system 11 ... Duct 12 ... Drain pot 13 ... Airtight container 14 for suction ... Suction motors 15a, 15b, 15c, 15d, 15e ... Piping 2 ... Constant pressure mechanism 20 ... First end plate 21 ... Heater 22 ... Aluminum block 23 ... Preheating container 24 ... Second end plate 25 ... Inlet port 26 ... Tube inlet mounting part 27 ... Tube support part 28 ... Resistance tube 29 ... Tube outlet mounting part 3 ... TOC meter 31 ... First conductivity Total 32 ... UV oxidative decomposition apparatus 33 ... Second conductivity meter 4 ... Pressure sensor

Claims (3)

A first end plate having a hollow heat conductor block, an inlet port, fixed to one end of the hollow portion of the heat conductor block, and a second end plate fixed to the other end of the hollow portion A preheating container having a sealed space in the hollow portion with the heat conductor block and the first and second end plates;
A heater for heating and adjusting the heat conductor block;
One end is fixed to a tube inlet mounting portion provided on the second end plate, and the tube support portion of the second end plate is passed from the tube inlet mounting portion to the outside of the preheating container. And a resistance tube having the other end fixed to a tube outlet mounting portion provided in the first end plate and introduced into the inside of the preheating container, and fluid flows from the inlet port to the tube. After being injected into the preheating container and preheated in the preheating container, the tube is attached from the tube inlet mounting portion to the resistance tube, and is sent out from the tube outlet mounting portion to the outside of the preheating container. The constant pressure mechanism is characterized in that the fluid is controlled to a constant pressure.   2. The constant temperature according to claim 1, wherein the entire preheating container is covered with a heat insulating material, including the portion of the resistance tube exposed from the preheating container via the outside of the preheating container. Pressure mechanism.   3. The constant value according to claim 1, wherein a cross-sectional area perpendicular to the fluid traveling direction of the preheating container is 30 times or more larger than a cross-sectional area perpendicular to the longitudinal direction of the resistance tube. Pressure mechanism.

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