JP2005257318A - Microflow measuring device and method for liquid - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device and method capable of easily measuring a microflow of a liquid from the number of droplets in a predetermined time by setting a droplet to be dropped within a site flow to a spherical shape of a fixed size, and setting the dropping speed of the droplet lower than that in air, thereby facilitating visual confirmation of the dropping droplet. <P>SOLUTION: In this microflow measuring device for liquid, a nozzle is provided within the site flow, and a second liquid which is not reacted or mixed with a droplet that is a first measuring liquid and makes this droplet recognizable out of the site flow is sealed therein. The microflow measuring method for liquid uses this device. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  In the present invention, when a very small amount of chemical solution is injected into a chemical device or the like by means of a pump or the like, the inflow of the chemical solution can be easily confirmed visually, and the flow rate of the chemical solution can be easily measured. The present invention relates to a flow rate measuring device.

The present invention also relates to a minute flow rate measuring method using the liquid minute flow rate measuring device.
Furthermore, the present invention relates to an apparatus for removing mercaptans from a mercaptan-containing hydrocarbon in which the above-described liquid micro flow rate measuring apparatus is installed.

In chemical apparatuses such as petroleum refining apparatuses and petrochemical apparatuses, liquid is continuously injected using means such as a pump in order to supply reaction raw materials, catalysts, and the like to the apparatus.
In order to perform a predetermined reaction and a predetermined process in the apparatus, it is necessary to control the injection amount of a liquid such as a chemical solution within a predetermined range according to the purpose of the reaction, process, etc. At the time of operation, it is necessary to set the flow rate of the liquid such as the chemical liquid within a predetermined range and periodically monitor whether the injection amount of the liquid such as the chemical liquid is appropriate or abnormal.

  A chemical pump is usually used to inject chemicals into the above chemical equipment. However, due to the amount of chemicals to be injected, the operating pressure of the reactor, and mechanical restrictions of the injectors, especially when the amount of chemicals injected is a minute flow rate. A reciprocating pump is widely used.

  However, since the reciprocating pump has a small pumping amount per one stroke and a pulsating flow is generated due to the structure of the pump, the actual situation is that there is no appropriate flow meter. It is difficult to ascertain whether it is being injected and whether the flow rate is appropriate.

  As a method of measuring the above flow rate, generally, a measuring glass is used to observe the level change of the chemical solution within a predetermined time, and the flow rate is calculated from the change amount. However, there is a problem that the flow rate is not measured correctly, for example, air is caught in the pump. In addition, the flow measurement method using measuring glass requires many operations such as valve operation, liquid level observation, and time measurement, which can be satisfied from the viewpoint of efficiency as the operation of the field operator during operation of the chemical equipment. is not.

  In addition, as a method of monitoring or confirming whether or not the chemical solution is actually injected, a method of providing a nozzle in the site flow, dropping the chemical solution from there, and monitoring or confirming the state of dripping from outside the site flow (so-called However, in this method, it is not always easy to visually monitor or confirm the droplets because the droplets dropping in the air have a small particle size and a high dropping speed. Further, there is a problem that the site flow is filled with the chemical liquid due to changes in the outside air temperature and / or flow rate, and the liquid droplets of the chemical liquid cannot be confirmed.

Japanese Patent Laid-Open No. 2003-21548 (Patent Document 1) has a small-diameter dropping hole for dropping a liquid supplied from the upper supply side into a supply path in a drip manner, and is dropped on the lower side of the dropping hole. A liquid supply detection device is provided which is provided with a pair of electrodes formed with a drop liquid conduction interval that is energized through the liquid, and that electrically detects the liquid drop formed at the above-described drop holes by passing the electrodes. Japanese Patent Laid-Open No. 63-170447 (Patent Document 2) has a nozzle provided in the site flow, and a small amount of liquid droplets dropped from the nozzle can be detected from the outside of the site flow with a photoelectric switch attached to a protective cover. An odorant detection device is disclosed.

However, these devices have the problems associated with the drip counter, and the explosion-proof performance is very difficult to adapt to chemical devices that handle large amounts of high-pressure gas and combustible materials. Have.
JP 2003-21548 A Japanese Utility Model Publication No. 63-170447

  The present invention eliminates the above-mentioned drawbacks of the prior art, makes the droplet dropping in the site flow into a sphere of a certain size, and makes the dropping speed slower than that in the air. It is an object of the present invention to provide an apparatus and a method that make it easy to visually check the falling droplets, and therefore can easily measure the minute flow rate of the liquid from the number of droplets dropped within a predetermined time.

  In order to solve the above problems, the present inventors have conducted various experiments, and as a result, the liquid droplets that do not react with and mix with the liquid droplets to be measured in the site flow and that drop in the site flow are the sites. By enclosing a liquid that can be recognized from the outside of the flow, the droplet to be measured dropping inside the site flow becomes a sphere of a certain size, and the falling speed of the droplet is slower than that in the air. Thus, the inventors have found that it is possible to easily measure a minute flow rate of a liquid, and have completed the present invention.

  That is, according to the first aspect of the present invention, in the apparatus for measuring the flow rate of the liquid dropped from the nozzle provided in the site flow, the liquid droplet that is the first liquid to be measured in the site flow. There is provided a device for measuring a minute flow rate of a liquid that does not react with and mix with the second liquid, and in which a second liquid is sealed so that the droplet can be recognized from outside the site flow.

  According to the second aspect of the present invention, in the method of measuring the flow rate of liquid by providing a nozzle in the site flow and dropping droplets from the nozzle, the first liquid to be measured in the site flow. There is provided a method for measuring a minute flow rate of a liquid that is performed by enclosing a second liquid that does not react with and mix with the liquid droplets and that the liquid droplets can be recognized from outside the site flow.

  Furthermore, according to a third aspect of the present invention, there is provided a micro flow rate measuring apparatus for a liquid according to the first aspect, wherein the first liquid to be measured is an aqueous solution and the second liquid is a hydrocarbon oil. Is done.

According to a fourth aspect of the present invention, there is provided the method for measuring a minute flow rate of a liquid according to the second aspect, wherein the first liquid to be measured is an aqueous solution and the second liquid is a hydrocarbon oil. Is done.
Furthermore, according to a fifth aspect of the present invention, in the first aspect, the first liquid to be measured is a metal phthalocyanine sulfonate aqueous solution, and the second liquid is desulfurized gas oil or atmospheric distillation reflux. An apparatus for measuring a minute flow rate of a liquid which is oil is provided.

  According to a sixth aspect of the present invention, in the second aspect, the first liquid to be measured is a metal phthalocyanine sulfonate aqueous solution, and the second liquid is desulfurized gas oil or atmospheric distillation reflux. A method for measuring the micro flow rate of a liquid, which is oil, is provided.

Furthermore, according to the seventh aspect of the present invention, in the apparatus for removing mercaptans in hydrocarbons by bringing a hydrocarbon containing mercaptans into contact with a mercaptans oxidation catalyst in the presence of an alkaline aqueous solution. An apparatus for removing mercaptans from hydrocarbons containing mercaptans provided with a device for measuring a minute flow rate of liquid according to the first aspect of the present invention is provided on the suction side of a pump installed in a supply line to the apparatus for removing mercaptans oxidation catalyst. The

  According to the liquid micro flow rate measuring apparatus and the micro flow rate measuring method of the present invention, since the inside of the site flow is sealed with the second liquid different from the first liquid to be measured, the liquid to be measured that drops in the site flow. The droplets become spherical with a certain size, and the rate at which the droplets fall is slower than that in the air, making it easy to visually check the falling droplets. Therefore, it is possible to easily measure the minute flow rate of the liquid.

  Moreover, since the injection of the chemical solution can be easily confirmed by visual observation, it is easy to check the injection amount and the presence / absence of abnormality during the circulation during the operation of the chemical apparatus.

  The liquid micro flow rate measuring apparatus and micro flow rate measuring method according to the present invention is applied to a metal phthalocyanine sulfonate aqueous solution that is a catalyst of an apparatus (sweetening process) for removing mercaptans contained in hydrocarbon oil in a petroleum refining apparatus. The injection into the apparatus will be described as an example.

  However, the liquid micro flow rate measuring apparatus and micro flow rate measuring method of the present invention are not limited to this example, and can be preferably used in other petroleum refining apparatuses and petrochemical apparatuses.

Apparatus An example of a micro flow rate measuring apparatus according to the present invention is shown in FIG.
The liquid minute flow rate measuring device of the present invention includes a chemical solution introduction line 1 connected to a metal phthalocyanine sulfonate aqueous solution supply tank (not shown), a site flow 2, and an oil supply line 3 for supplying oil for sealing. , A vent line (not shown) and a suction line 4 connected to the suction side of the reciprocating pump. In the site flow 2, a drop nozzle 5 for the liquid to be measured is provided.

  That is, when a pump (not shown) sucks the chemical solution, the chemical solution is supplied from the chemical solution introduction line 1 to the dropping nozzle 5, and the chemical solution becomes droplets from the dropping nozzle 5 and falls in the site flow 2. The droplet is considered to be a droplet having a certain size due to the interfacial tension between the chemical solution and the encapsulated oil, the specific gravity difference, the flow rate of the chemical solution, and the like. Moreover, since the metal phthalocyanine sulfonate aqueous solution descends slowly in the enclosed oil, it is easy to confirm the droplets.

The flow rate of the droplets can be easily calculated by measuring the number of drops (drops / minute) of the aqueous metal phthalocyanine sulfonate solution within a predetermined time, as will be described later.
The liquid micro flow rate measuring device of the present invention is described as being installed in the suction line connected to the suction side of the reciprocating pump, but is installed in the discharge line connected to the discharge side of the reciprocating pump. Also good.

The inner diameter of the dropping nozzle used in the dropping nozzle present invention, the injection amount of the liquid medicine, such as by the type of oil to be encapsulated, site flow outwardly from the droplet to check it as a size, and so that the dropping amount of the desired droplet It can be set appropriately. The inner diameter of the dropping nozzle is usually 1 to 12 mm, preferably 6 to 10 mm, and more preferably 6 to 8 mm.

  In the injection amount (about 0.1 to about 0.4 liter / hour) of the metal phthalocyanine sulfonate aqueous solution in the sweetening process in the petroleum refining apparatus exemplified here, it is usually 6 to 10 mm, preferably 6 to 8 mm. A dripping nozzle may be desirably used.

When the inner diameter of the dropping nozzle is less than this range, it is difficult to confirm the dropped droplet and measure the flow rate of the chemical because the droplet is too small or the dropping amount (drop / min) is increased.
If the inner diameter of the dropping nozzle exceeds this range, the liquid drop will not be formed or the liquid drop will not be of a certain size, or the drop volume (drops / minute) will be too small. It is difficult to confirm the flow rate and to measure the flow rate of the chemical.

Moreover, the material of a dripping nozzle can use the same material as the piping which installs the flow measuring device of this invention normally.
Encapsulated oil The encapsulated oil used in the present invention does not react with and mix with the dripping chemical solution, has sufficient fluidity in the operating temperature range, and droplets dripping in the site flow can be recognized from outside the site flow. It is necessary to be. For example, when the chemical solution is a metal phthalocyanine sulfonate aqueous solution (specific gravity of about 1.1 to about 1.2), it is preferable to use hydrocarbon oil because of its price and availability.

In other words, the sealing oil may be selected as appropriate so that the drops to be dropped have a hue that allows the drops to be easily recognized, and the drop amount of the drops falls within a desired range.
As the hue of the encapsulated oil, those having transparency and a slight degree of coloring can usually be preferably used. Although it can select suitably by the kind of chemical | medical solution dripped, if an example is given, the thing of +25 or more, preferably +28 or more will be desirably used in Saybolt color. Alternatively, the ASTM color is desirably 1.5 or less, preferably 1 or less. Further, those having less fluorescent color are preferable, and those having no fluorescent color are more preferable.

When the Saybolt color is less than +25 or the ASTM color is more than 1.5, it is difficult to recognize the droplet.
Examples of the encapsulated oil used in the present invention include cracked gasoline, atmospheric distillation tower reflux oil, via desulfurization, and liquid paraffin. Of these, desulfurized gas oil and atmospheric distillation tower reflux oil are preferable, and atmospheric distillation tower reflux oil is more preferable.

The specific gravity of these encapsulated oils is usually 0.74 to 0.87, preferably 0.81 to 0.84.
Micro flow rate measurement method Change the stroke of the reciprocating pump in advance to obtain the relationship between the injection amount of the metal phthalocyanine sulfonate aqueous solution and the number of droplets dropped within a predetermined time, and thereafter drop within the predetermined time. By measuring the number of droplets to be measured, the injection amount (micro flow rate) can be obtained.

When the combination of the droplet to be measured and the sealed oil changes, the relationship between the injection amount and the droplet amount to be dropped may be obtained again.
Further, in the cyclic monitoring during the operation of the apparatus, it is possible to easily confirm whether the flow rate is appropriate or to measure the minute flow rate by measuring the dropping amount (drops / min) of the chemical solution visually or by a stopwatch.

Further, the droplet detection or flow rate measurement may be performed from the outside of the site flow using, for example, a photoelectric switch.
[Example]
In order to describe the minute flow rate measuring apparatus and minute flow rate measuring method of the present invention in more detail, the present invention will be specifically described below with reference to the following examples. It is not limited by.
[Examples 1 to 3 and Comparative Example 1]
Cobalt phthalocyanine sulfonate aqueous solution is used as the chemical solution, the inside diameter of the dropping nozzle in the site flow is set to 8 mmφ, and the stroke of the reciprocating pump is set to 100% (flow rate 0.28 liter / hour). The type of oil was changed, and the ease of visual confirmation of dropping of cobalt phthalocyanine sulfonate droplets and the dropping rate were measured.

  The results are summarized in Table 1.

In Example 1, it was recognized that the dropping speed was slightly high and the dropping particle size was slightly small.
In Example 2, it was recognized that both the dropping speed and the dropping particle size were preferable.
In Example 3, it was recognized that the fluorescent color as a hue was strong and the confirmability of the droplet was slightly inferior.
Example 4
Using the same micro flow rate measurement device as used in Example 2 above, changing the stroke of the reciprocating pump and measuring the drop amount (drops / minute) and the injection amount (micro flow rate) (liters / hour) did.

The results are shown in Table 2.
From Table 2, a very good correlation is observed between the drop amount and the injection amount (micro flow rate). Therefore, by measuring the number of drops (drop amount) within a predetermined time, cobalt phthalocyanine sulfate is measured. It was confirmed that the injection amount (micro flow rate) of the phonate solution can be easily measured.

  By making the droplets dripping in the site flow into a spherical shape of a certain size and making the droplet drop speed slower than that in the air, it is easy to liquid from the number of droplets dropped within a predetermined time It is possible to provide an apparatus and a method capable of measuring a minute flow rate.

FIG. 1 is a diagram showing an example of a liquid micro flow rate measuring apparatus according to the present invention.

Explanation of symbols

1. 1. Chemical solution introduction line 2. Site flow 3. Oil supply line 4. Inhalation line Dripping nozzle

Claims (7)

  In a device for providing a nozzle in a site flow and measuring a flow rate of a liquid dropped from the nozzle, the liquid does not react with and mix with a liquid that is a first liquid to be measured in the site flow. A device for measuring a minute flow rate of a liquid, wherein a second liquid that can be recognized from outside the site flow is sealed.   In the method of measuring the flow rate of the liquid by providing a nozzle in the site flow and dropping a droplet from the nozzle, the liquid does not react with and mix with the droplet that is the first liquid to be measured in the site flow, and A method for measuring a minute flow rate of a liquid, comprising: sealing a second liquid so that the droplet can be recognized from outside the site flow.   The apparatus for measuring a minute flow rate of liquid according to claim 1, wherein the first liquid to be measured is an aqueous solution, and the second liquid is a hydrocarbon oil.   The method for measuring a minute flow rate of a liquid according to claim 2, wherein the first liquid to be measured is an aqueous solution, and the second liquid is a hydrocarbon oil.   2. The minute flow rate measurement of the liquid according to claim 1, wherein the first liquid to be measured is a metal phthalocyanine sulfonate aqueous solution, and the second liquid is desulfurized gas oil or atmospheric distillation reflux oil. apparatus.   The minute flow rate measurement of the liquid according to claim 2, wherein the first liquid to be measured is a metal phthalocyanine sulfonate aqueous solution, and the second liquid is desulfurized gas oil or atmospheric distillation reflux oil. Method.   In an apparatus for removing mercaptans in hydrocarbons by contacting a hydrocarbon containing mercaptans with a mercaptan oxidation catalyst in the presence of an alkaline aqueous solution, supply the mercaptan oxidation catalyst to the supply line to the removal apparatus. An apparatus for removing mercaptans from a hydrocarbon containing mercaptans, wherein the apparatus for measuring a minute flow rate of liquid according to claim 1 is provided on the suction side of an installed pump.

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