JPH0419422B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a re-inspection plant for containers that recover liquefied petroleum gas, and in particular, to a plant for re-inspecting containers that recover liquefied petroleum gas, and in particular, to a plant for re-inspecting containers that recover liquefied petroleum gas, and in particular, a plant for re-inspecting containers that recover liquefied petroleum gas. The present invention relates to a re-inspection plant for liquefied petroleum gas storage containers, which is characterized by a method and apparatus for treating waste gas and waste liquid discharged by cleaning and drying the containers in the inspection process.

Conventional technology and problems In general, containers for storing liquefied petroleum gas (hereinafter referred to as "containers") must be inspected for pressure resistance, airtightness, etc. according to the High Pressure Gas Control Law, depending on the internal volume and age of use. Containers currently in use must be re-inspected for pressure resistance and airtightness after a specified period of time.

At this time, unused liquefied petroleum gas remains in the currently used container to be re-inspected, and the remaining liquid and gas in the container must be recovered as a pre-treatment step for the container inspection.

Conventionally, the residual liquid recovered in the pretreatment process is stored in a residual liquid storage tank, but the recovered residual gas has a small volume near atmospheric pressure, and it is similar to the residual gas extracted by water displacement. The residual gas contains water vapor, and the equipment required to reuse the residual gas is too expensive, and in reality, it is discharged into the atmosphere without being reused. however,
Disposing of such residual gas involves the smell of LP gas odorants and risks such as explosions and fires, which cause discomfort and anxiety to local residents.

Regarding the recovered residual liquid, the residual liquid stored in the residual liquid storage tank is separated into a liquid component and a vaporized gas component within the tank. In general, the concentration of light components in the vaporized gas content of the residual liquid is always higher than the concentration of light components in the residual liquid.For this reason, when the vaporized gas content of the residual liquid is drawn out from the residual liquid storage tank, the residual liquid The concentration of the heavy components in the tank increases, and eventually only the heavy components remain in the residual liquid storage tank. Further, the temperature of the residual liquid, which has increased in heavy content, in the residual liquid storage tank decreases in temperature due to the heat of vaporization of the light content, and gradually settles in the residual liquid storage tank without being vaporized even at room temperature. Therefore, after the residual liquid storage tank has been used for a certain period of time, it is necessary to periodically collect the heavy components of the residual liquid from within the tank. However, the heavy components of the residual liquid are not of high quality, making it difficult to use for home consumption, and causing various problems when discarded.

Furthermore, water, steam and air used for cleaning and drying containers after residual liquid and residual gas have been collected are conventionally discharged into rivers and the atmosphere. These waste air and liquids contain additives to cleaning water, oily substances, metallic substances, etc., and if they are disposed of without proper treatment, they will contaminate the air and rivers. It turns out.

Purpose of the Invention The purpose of the present invention is to remove residual gas and residual liquid recovered in the pretreatment process of the inspection, as well as cleaning and drying of the containers in the inspection process, in the re-inspection of containers for recovering liquefied petroleum gas. It is an object of the present invention to provide a re-inspection plant for liquefied petroleum gas storage containers, which can appropriately recover and purify heavy components in waste gas and waste liquid discharged.

Means for Solving the Problems The above objects are achieved in a re-inspection plant for liquefied petroleum gas storage containers according to the present invention. To summarize, the present invention includes a recovery means for recovering residual liquid and residual gas remaining in a liquefied petroleum gas storage container, a residual liquid storage tank for storing residual liquid from the recovery means, and a residual liquid and residual gas. Inspection means for inspecting the pressure resistance and airtightness of a liquefied petroleum gas storage container from which gas has been recovered;
a gas-liquid separation tank that collects waste air and waste liquid generated from the inspection means and separates gas and liquid; a filtration unit that filters the liquid from the gas-liquid separation tank to obtain clean water;
Liquefied petroleum gas storage characterized by comprising a combustion means for burning the gas phase separated in the gas-liquid separation tank, the residual liquid from the residual liquid storage tank, and the residual gas from the recovery means. This is a container re-inspection plant.

Further, according to the present invention, the filtration means is an upflow sand filter tank, and the combustion means further includes a preheater formed by forming a steam pipe into a spiral shape, and surrounding the preheater. The lower end of the steam pipe is connected to the supply piping line for residual liquid from the residual liquid storage tank and residual gas from the recovery means, and the other end is connected to the inner surface of the outer cylinder. the helical center of the evaporator tube at the bottom of the preheater; A nozzle is installed at the outlet,
Furthermore, an outlet of a piping line for the gas phase separated in the gas-liquid separation tank is opened in the upper part of the outer cylinder.

Embodiment Next, a re-inspection plant for liquefied petroleum gas storage containers according to the present invention will be described in more detail with reference to the drawings.

FIG. 1 shows a system diagram of a re-inspection plant for liquefied petroleum gas storage vessels. In liquefied petroleum gas storage container re-inspection plants, unused liquefied petroleum gas often remains in currently used containers to be re-inspected. Collected as a pre-processing step for container inspection. Usually, in order to improve the recovery efficiency of residual liquid and residual gas, the residual liquid is recovered first.
Hereinafter, this step will be referred to as the "first step."

In carrying out the first step, first, the container B is attached to the residual liquid recovery inversion stand 100 that constitutes the residual liquid recovery means, and then it is overturned. A container connector 101 is connected to the opening of the container B. The container connector 101 is connected to a piping line 102 and a residual liquid recovery pump 1.
03, is connected to the residual liquid storage tank 108 via piping lines 104, 106, and 107. Also, residual liquid storage tank 1
08 is a surge tank 110 in the piping line 109
connected to.

With the above configuration, the residual liquid in the container B is removed by the residual liquid recovery pump 103 and the piping lines 102, 104, 10.
6,107, the high-pressure residual liquid vaporized gas (its composition mainly consists of light components) is supplied to the residual liquid storage tank 108 and naturally vaporized in the residual liquid storage tank 108.
08 and the surge tank 110, the piping line 10 is connected to the top of the residual liquid storage tank 108.
9 and flows into the surge tank 110, where it is temporarily stored. The vaporized gas portion of the residual liquid stored in the surge tank 110 is supplied for industrial use or for self-consumption through a piping line 111 or 112 as required.

The vaporized gas in the residual liquid storage tank 108 is transferred to the piping line 1.
When the gas flows into the surge tank 110 through 09 or when gas is discharged from the surge tank 110, heavy gas that has vaporized in the residual liquid storage tank 108 The vaporized gas content of residual liquid such as mass may liquefy in the surge tank 110, and the surge tank 1
A liquid phase component will also exist within 10. Therefore, in order to return the heavy residual liquid in the surge tank 110 to the residual liquid storage tank 108, the piping line 11 is
9 is provided. When collecting the liquid phase remaining at the bottom of the surge tank 110 into the residual liquid storage tank 108, close the valve V4 provided in the piping line 104 and open the valve V3 provided in the piping line 119 to collect the liquid phase. The amount is temporarily stored in a drain pot 105 provided in a piping line 105. Thereafter, when the valve V3 is closed and the valve V4 is opened, the residual liquid collected from the container B and pumped through the piping lines 102 and 103 flows into the residual liquid storage tank 108 through the piping lines 106 and 107.

Residual gas remains in the container B from which the residual liquid has been collected in the above manner, and in order to collect the residual gas, the container B is returned to its normal normal posture and placed on the tipping table 100 for residual liquid collection. removed from Hereinafter, the residual gas recovery process will be referred to as the "second process."

In carrying out the second step, a container connector 1, which also constitutes a part of the collection means, is placed at the opening of the container B removed from the tipping table 100 for residual liquid collection.
13 are connected. The outlet of the container connector 113 is connected to combustion means, which will be described later, via piping lines 19 and 20.
That is, it is connected to the combustion tube 13. The remaining gas in this process is spontaneously released from container B until its pressure equilibrates with atmospheric pressure and the flow stops.

Next, container B where the flow of residual gas in the container has stopped
is removed from the container connector 113 and sent to an inspection means for performing a pressure resistance test, an airtightness test, and cleaning of the container B, that is, a water-filled pressure washing equipment 114.
This step is hereinafter referred to as the "third step." Usually, the pressure resistance and airtightness of a container are tested by filling the container with water and applying water pressure. In this step, the residual gas in the container that could not be completely recovered in the second step is further recovered.

When carrying out the third step, since the specific gravity of the residual gas is greater than that of air and accumulates in the container B, a piping line is connected to the opening of the container B through the container connecting device 115 with the opening of the container B facing upward. 116 and 117 are connected. Water in container B is injected through piping line 116, thereby expelling residual gas in container B, and recovered from container B via piping line 117. The piping line 117 is connected to the piping line 1, and therefore, the residual gas is sent to the gas-liquid separation tank 4, which will be described in detail later, via the piping line 1 and the piping line 3.

Container B from which residual gas has been discharged in the above process is tested for pressure resistance and airtightness in a conventional manner. Such testing methods are well known to those skilled in the art and will not be further described.

After the pressure resistance and airtightness tests have been completed, the container B is then attached to the container overturn table 118 of the water-filled pressure washing equipment 114, and the piping lines 120 and 121 are connected to its opening via the container connection device 119, as shown in the figure. It's like falling down. Piping line 1 in container B
High-temperature, high-pressure steam is injected through the pipe line 120, so that the test water in the third step flows into the piping line 121.
collected through. Hereinafter, this step will be referred to as the "fourth step."

When carrying out the fourth step, the inside of the container B is cleaned by the stirring action of water caused by bubbles generated by the supplied water vapor. The water in the container B is discharged to the gas-liquid separation tank 4 via a piping line 121, a piping line 2 connected to the piping line 121, and a piping line 3. Even after all of the water in container B has flowed out, cleaning continues with high-temperature, high-pressure steam being pressurized. When the cleaning of the container B is completed, dry air is flowed into the container B from the piping line 120 to dry the inside of the container. The air that has absorbed moisture inside the container B flows out through the piping lines 121, 2, and 3, and is sent to the gas-liquid separation tank 4.

As understood from the above description and the detailed description below, according to the present invention, waste gas, waste liquid, residual gas, and heavy components in the residual liquid can be appropriately recovered and purified. In other words, waste gas and waste liquid such as air, steam, and water used for pressure and airtightness tests for container re-inspection and for cleaning inside the container are passed through the first tank, the gas-liquid separation tank 4, to form a gas phase. The liquid phase is separated, and the separated waste liquid is purified by passing it through a second filtration tank installed adjacent to the first layer, and the remaining gas and liquid recovered in the pre-treatment for the inspection are collected at room temperature. Also, the heavy residual liquid that does not vaporize in the residual liquid storage tank 108 or has a small amount of vaporization and gradually settles to the bottom thereof can be used as fuel for incineration of the waste gas separated in the first tank. These waste gases, waste liquids, residual gases, and residual liquids are processed in parallel.

Next, the configuration according to the present invention as described above will be explained in more detail.

First, we will discuss two tanks that separate and purify waste gas and waste liquid into gas and liquid phases. As mentioned above, the residual gas in container B, which has been replaced with water in the water-filled pressure washing equipment 114, is sent to the gas-liquid separation tank 4 via the piping lines 1 and 3, and is also used for the pressure test of container B. The water, high-temperature, high-pressure steam and air used for washing and drying are sent to a gas-liquid separation tank 4 via piping lines 2 and 3. As illustrated in Figure 2,
Pipe line 3 connected to pipe lines 1 and 2
The outlet 3a of the piping line 3 is located close to the bottom 4a of the tank in order to prolong the time it takes for bubbles formed by high-temperature, high-pressure water vapor or residual gas to pass through the liquid in the gas-liquid separation tank 4. Provided for.

The gas-liquid separation tank 4 is made of concrete and has a box shape, and contains therein the waste liquid fed through the piping line 3. Further, the high-temperature, high-pressure water vapor passes through the piping lines 2 and 3, passes through the waste liquid remaining in the tank in the form of bubbles, and is cooled and condensed by the waste liquid while reaching the liquid level 4b. Furthermore, a part of the residual gas floats in the waste liquid in the form of small bubbles or melts, but most of it passes through the waste liquid and is collected by the gas phase collection section 5 located at the upper part of the tank 4. , flows into a combustor 13, which will be described later, via a piping line 6.

In this way, the suspended matter in the container B, which is contained in the waste air and waste liquid, becomes turbid as a waste liquid in the gas-liquid separation tank 4 and temporarily remains in the tank 4. As time passes, several kinds of suspended substances in the waste liquid in the gas-liquid separation tank 4 emulsify with the liquid content of the waste liquid, mainly water, or separate into several layers depending on their specific gravity and precipitate.

In order to purify such waste liquid, in the present invention, a sand filtration tank 7 is provided as a second tank adjacent to the residual liquid separation tank 4. The sand filtration tank 7 is generally an upflow type sand filtration tank that is capable of filtering highly turbid waste liquid, can capture a large amount of suspended solids, and can perform high-speed filtration. An example of the structure of the sand filter tank 7 is shown in FIG.

More specifically, the sand filter tank 7 is integrally formed with concrete in a box shape adjacent to the gas-liquid separation tank 4. The sand filtration tank 7 and the gas-liquid separation tank 4 are separated by a partition wall 8 and communicated through a channel 9 formed at the bottom of the partition wall 8. A water collection channel 7a is provided at the bottom of the sand filtration tank 7, which is the second tank, and from this, filter media with finer particle sizes are sequentially stacked toward the top of the tank, and at the top, filter media with extremely small particle sizes and uniform filtration material are layered. Provide sand. The structure of such a sand filter tank 7 is well known to those skilled in the art, so further explanation will be omitted.

The waste liquid sent to the gas-liquid separation tank 4 is
Due to the water head difference between the water and the sand filtration tank 7, the water flows from the bottom of the gas-liquid separation tank 4 through the flow path 9 to the sand filtration tank 7 through the water collection hole 7.
a, and rises and flows inside the sand filter tank 7. In this process, the waste liquid is purified by trapping suspended solids in the filter media in the filter layer. The purified waste liquid flows out from a weir (not shown) provided above the partition wall of the filtration layer 7 and is disposed of.

In the present invention, the particle size of the filter medium of the sand filter tank 7, the thickness and width of the filter layer are set in the water-filled pressure washing equipment 1.
It is determined by considering the processing capacity of 14 containers per day. In general, the upflow sand filter tank 7 has a high processing capacity as described above, and is simple in structure and easy to maintain.
This filter tank is suitable for industrial use because it is easy to manage.

The gas (waste gas) passed through the waste liquid in the gas-liquid separation tank 4 as described above and collected by the gas phase collection unit 5 located at the upper part of the tank 4 is shown in FIG. As shown, the water flows into the pressurizer 10 through the piping line 6, and then is fed under pressure from the pressurizer 10 and flows into the water seal 11. Thereafter, it is fed to the combustion cylinder 13 via the piping line 12. The water seal 11 is the combustion tube 1
This is provided to prevent backfire from 3.
The pressurizer 10 and the water seal 11 have structures well known to those skilled in the art, and further explanation will be omitted.
Further, although two combustion tubes 13 are provided in this embodiment, the present invention is not limited to this, and any number can be provided as necessary.

As shown in FIG. 3, the combustion tube 13 includes a preheater 14 formed by spirally forming a steam pipe 16, and an outer tube 15 disposed surrounding the preheater 14. A piping line 12 from a water seal 11 is connected above the outer cylinder 15. The lower end 16a of the steam pipe 16 is connected to the piping line 20, and the other end 16b is spirally wound along the inner surface of the outer cylinder 15 from the bottom to the top, and then spirally connected to the inner surface of the outer cylinder 15. It descends between the outer surface of the shaped preheater 14 and leads to the vicinity of the helical center of the evaporation tube 16 at the bottom of the preheater 14, and a nozzle 17 is provided at the outlet thereof. Therefore, the nozzle 17 is connected to piping lines 18 and 19 and 20.
The residual liquid and residual gas are supplied through the combustion chamber and combusted. A general mechanical or electronic ignition device 22 consisting of a coil and a magnet is attached to the side of the combustion tube 13 via a heat insulating material, and the combustion tube 13 is ignited by remote control. .

With such a configuration of the combustion tube 13, the residual gas recovered in the second step and supplied through the piping lines 19 and 20 is combusted as it is, and either does not vaporize at room temperature from the residual liquid storage tank 108 or has a small amount of vaporized gas. The residual liquid with a small amount of heavy content is preheated and forcibly vaporized while passing through the preheater 14, and then is ejected from the nozzle 17 and burned. Furthermore, by combustion of the gas, the waste air supplied from the gas-liquid separation tank 4 to the combustion tube 13 via the piping line 12 is also incinerated, and a portion of the exhaust heat from the combustion is used to preheat the subsequent residual liquid. used for.

The distance from the center of the piping line 12 provided on the side of the outer cylinder 15 to the nozzle 17, the nozzle 17
The diameter of the fuel is determined by taking into account the average length of the flame, flame conditions such as turbulence and local temperature, and the characteristics of the fuel. By structuring the combustion tube 13 as described above, the flame is sufficiently mixed with the air flowing in from the bottom of the outer tube 15 by natural convection and diffused therein, and spreads from the mouth end of the nozzle 17 to the entire preheater 14. This extends to the upper part of the outer cylinder 15, and the waste gas from the gas-liquid separation tank 4 can be completely incinerated.

Piping lines 18 and 19 have operating valves V1 and V.
2, and by operating appropriate valves, when supplying residual liquid to the combustion cylinder 13, operation valve V1 is closed and operation valve V2 is opened, and when residual gas is supplied, operation valve V1 is opened and operation valve V2 is opened. Close operation valve V2. By this operation, it is possible to selectively supply the residual gas or the heavy portion of the residual liquid to the combustion tube 13 as necessary, and also to adjust the amount of the supply appropriately. For example, when igniting the combustion tube 13 when the preheater 14 has not been preheated, the heavy residual liquid does not vaporize at room temperature, or the amount of vaporization is small and it is difficult to ignite, so The remaining gas is supplied to the combustion tube 13 and ignited. In this case, if the operating valve V1 is opened with the operating valve V2 closed, the residual gas is supplied to the combustion cylinder 13 by the differential pressure between its vapor pressure and atmospheric pressure. After that, when V1 is closed and V2 is opened, the residual liquid is supplied to the combustion tube 13 by the difference between its vapor pressure and atmospheric pressure, but since the preheater 14 is sufficiently preheated, it vaporizes and ignites. do.

Effects of the Invention According to the liquefied petroleum gas storage container re-inspection plant of the present invention, 1. The heavy residual liquid that does not vaporize at room temperature or has a small amount of vaporization and settles in the storage tank is recovered from the storage tank. By burning the forced vaporized gas or the remaining gas in the container together with the waste gas,
These can be deodorized, eliminating the possibility of emitting bad odors around inspection and treatment facilities.

2. There is no need to periodically remove heavy residual liquid or drain (suspended substances) from the residual liquid storage tank.

3. Suspended substances can be removed from waste liquid and disposed of without emitting a bad odor to the surrounding area.

etc. benefits can be obtained.

[Brief explanation of drawings]

FIG. 1 is a system diagram of a re-inspection plant for liquefied petroleum gas storage containers according to the present invention. FIG. 2 is a sectional view of the gas-liquid separation tank and the filtration tank. Figure 3 shows
FIG. 3 is a partial cross-sectional view of a combustion tube. 4... Gas-liquid separation tank, 7... Filtration tank, 10... Pressurizer,
DESCRIPTION OF SYMBOLS 11...Water seal, 13...Combustion cylinder, 108...Residual liquid storage tank, 110...Surge tank.

Claims (1)

[Claims] 1. A recovery means for recovering the residual liquid and residual gas remaining in the liquefied petroleum gas storage container, a residual liquid storage tank for storing the residual liquid from the recovery means, and a liquefier from which the residual liquid and gas have been recovered. an inspection means for inspecting the pressure resistance and airtightness of a petroleum gas storage container; a gas-liquid separation tank for collecting waste gas and waste liquid generated from the inspection means and separating gas and liquid; an upflow sand filtration tank that filters the liquid component of the water to produce clean water, the gas phase separated in the gas-liquid separation tank, the residual liquid from the residual liquid storage tank, and the residual gas from the recovery means. a combustion means for combusting, the combustion means comprising a preheater formed by forming a steam pipe into a spiral shape, and an outer cylinder disposed surrounding the preheater, The lower end of the steam pipe is connected to the supply piping line for residual liquid from the residual liquid storage tank and residual gas from the recovery means, and the other end spirally extends from the bottom to the top along the inner surface of the outer cylinder. and then descends between the inner surface of the outer cylinder and the outer surface of the helical preheater, leading to the vicinity of the helical center of the evaporation tube at the bottom of the preheater, and a nozzle is provided at the outlet thereof. . A re-inspection plant for liquefied petroleum gas storage containers, further comprising an outlet of a piping line for the gas phase separated in the gas-liquid separation tank at the upper part of the outer cylinder.