阅读说明：本技术 检测和防止泄漏的方法 (Method for detecting and preventing leakage ) 是由 罗纳德·于尔根·霍费尔 托马斯·普法夫尔 克里斯蒂安·施泰因布鲁格 于尔根·赫布格尔 罗伯特 于 2019-12-20 设计创作，主要内容包括：本发明涉及一种用于检测和防止用于储存有毒、腐蚀性、刺激性和/或易燃介质的双壁容器(2)的泄漏的方法,其中双壁容器(2)具有内壁(3)和外壁(4),其中内壁(3)和外壁(4)之间形成有腔体(5),其中在腔体(5)内产生正压力,其中,在内壁(3)泄漏的情况下,向腔体(5)供给气体以保持腔体(5)内的正压力,并向对应的容器系统(1)供给气体,该容器系统具有用于对管路(8)中的气体通流进行开环/闭环控制的开环/闭环控制装置并具有用于测量双壁容器(2)的腔体(5)内的压力的压力测量单元(11)。(The invention relates to a method for detecting and preventing a leak in a double-walled container (2) for storing toxic, corrosive, irritant and/or inflammable media, wherein the double-walled container (2) has an inner wall (3) and an outer wall (4), wherein a cavity (5) is formed between the inner wall (3) and the outer wall (4), wherein a positive pressure is generated in the cavity (5), wherein, in the event of a leak in the inner wall (3), a gas is supplied to the cavity (5) in order to maintain the positive pressure in the cavity (5), and a corresponding container system (1) is supplied with a gas, which container system has an open/closed-loop control device for open/closed-loop control of the gas through-flow in a pipeline (8) and has a pressure measuring unit (11) for measuring the pressure in the cavity (5) of the double-walled container (2).)

1. A method for detecting and preventing leakage of a double-walled container (2) for storing toxic, corrosive, irritant and/or inflammable media, wherein the double-walled container (2) has an inner wall (3) and an outer wall (4), wherein a cavity (5) is formed between the inner wall (3) and the outer wall (4), and wherein a positive pressure is generated within the cavity (5), characterized in that, if a leakage occurs in the inner wall (3), gas is supplied to the cavity (5) to maintain the positive pressure within the cavity (5).

2. Method according to claim 1, characterized in that at least one gas, preferably at least one gas and at least one liquid, is supplied to the container (2).

3. Method according to claim 2, characterized in that the positive pressure inside the cavity (5) is measured, preferably by measuring the pressure of the gas supplied to the double-walled container (2) and measuring the pressure of the gas supplied to the cavity (5) and calculating the difference between these two pressures.

4. Method according to claim 2 or 3, characterized in that the pressure and/or through-flow of the gas supplied to the cavity (5) is controlled such that the positive pressure inside the cavity (5) is between 5 and 50 mbar, preferably between 10 and 30 mbar, relative to the pressure inside the double-walled container (2).

5. Method according to any one of claims 1 to 4, characterized in that the liquid stored in the double-walled container (2) flows out of the container due to a leak in the inner wall (3) and accumulates in the cavity (5), being transported at the lowest point of the cavity (5) via a drain line (13) into a monitoring container (14), wherein the monitoring container (14) is partially filled with another liquid, preferably water, in particular fully desalinated water or softened industrial water.

6. Method according to claim 5, characterized in that the level and/or the temperature and/or the conductivity of the liquid in the monitoring container (14) is measured in order to detect a leak in the double-walled container (2).

7. Method according to claim 5 or 6, characterized in that an alarm is triggered as soon as a predetermined limit value of the level and/or the temperature and/or the conductivity of the liquid in the monitoring container (14) is reached.

8. Method according to any one of claims 5 to 7, characterized in that, as soon as the level of liquid in the monitoring container (14) reaches a limit value, the monitoring container (14) is emptied via a bottom discharge valve (20) into another container, preferably an Intermediate Bulk Container (IBC) (19).

9. A container system (1) for storing toxic, corrosive, irritant and/or combustible media, the container system comprising:

-a double-walled container (2) having an inner wall (3) and an outer wall (4), wherein a cavity (5) is formed between the inner wall (3) and the outer wall (4);

-a compressor, preferably a side channel blower (9);

-a conduit (8) provided for conveying gas and for connecting the outer wall (4) to the compressor;

-an open/closed loop control device, preferably a control valve, in particular a bypass control valve (12), for open/closed loop control of the through-flow of gas in the line (8); and

-a pressure measuring unit (11) for measuring the pressure within the cavity (5) of the double-walled container (2).

10. Container system (1) according to claim 9, characterized in that: a monitoring container (14), said monitoring container (14) being connected to the lowest point of said cavity (5) of said double-walled container (2).

11. Container system (1) according to claim 9 or 10, wherein: a flow meter (10), the flow meter (10) for measuring a flow rate of gas supplied to the cavity (5) of the double-walled container (2).

12. The container system (1) according to one of claims 9 to 11, characterized in that the monitoring container (14) has a measuring device, in particular a radar measuring device (15), for measuring the liquid level.

13. Container system (1) according to one of claims 9 to 12, characterized in that the monitoring container (14) has a conductivity sensor (17) and/or a temperature sensor (18), wherein preferably a multi-parameter transmitter is provided for evaluating the measurement of the conductivity and/or the temperature.

14. The container system (1) according to any of claims 9 to 13, wherein the inner wall (3) and the outer wall (4) of the double-walled container (2) are lined with a barrier layer, preferably comprising perfluoroalkoxy Polymer (PFA).

15. Use of the double-walled vessel (2) of the vessel system (1) according to any of claims 9 to 14 as an acid condensate tank in a desulfurization process, preferably a Wet Sulfuric Acid (WSA) process.

Technical Field

The present invention relates to a method for detecting and preventing leaks in double-walled containers for storing toxic, corrosive, irritating and/or combustible media and a corresponding container system.

Background

Double-walled containers have an inner wall and an outer wall and are particularly useful for reducing the likelihood of leakage of the medium stored therein. In comparison with a container with only one wall, the advantage is to be seen in that the outer wall prevents the stored medium from flowing out in the event of a leakage opening in the inner wall. In this case, the storage of toxic, corrosive, irritant and/or inflammable media which cannot be released into the environment is of particular relevance. The storage of corrosive media in containers represents a particular challenge, since media of this type can corrode the walls of the containers in which they are stored, thus possibly leading to leaks. The leak detection device has proven successful in preventing damage to the inner and outer walls of a container for storing a corrosive medium. These devices detect leaks in the inner wall and send a signal to the operator of the system comprising the container so that the operator can react to the leak in the inner wall of the container and prevent the medium from flowing out of the container.

Double-walled containers of this type are known, for example, from EP1179505a 1. This publication discloses herein an apparatus for storing a liquid, which apparatus comprises a double-walled vessel, an outlet in the form of a double-walled pipe arranged at the lowest point of the vessel, and two shut-off devices connected by a connecting element. The double-walled container, the double-walled pipeline and the two shut-off devices each have a monitoring space, wherein the monitoring spaces communicate with each other to prevent uncontrolled outflow of the liquid stored in the container. The common monitoring space is monitored using a pressure-based leak indicator that sends a signal to an annunciator in the event of a leak. A disadvantage of this device is that this type of leak detection is only suitable for liquids and not for gases. Another disadvantage is seen in the accumulation of liquid in the monitoring spaces of the containers, lines and cut-offs in the event of a leak.

DE4135200A discloses a leakage indicator for double-walled containers, double-walled pipes and the like for storing and transporting water-contaminated liquids. The leak indicator comprises a pressurized monitoring space of a vessel or pipe formed by an inner jacket and an outer jacket. The pressure drop in the monitored space caused by the natural leakage of the leakage indicator and the supply line during normal operation is compensated within a predetermined control range by refilling the compressed gas reservoir with compressed gas after the solenoid valve is opened by the refill pressure switch via the throttle device in the supply line.

US2012/136579a1 discloses a method for determining and quantifying a leakage between a first pipe and a second pipe, wherein the first pipe is at least partially surrounded by the second pipe. The measuring device comprising a flow meter and a pressure gauge may generate a constant pressure difference between the pipes in case of a leak in the first pipe.

DE4320986a1 describes a different type of conveying line and a method for monitoring a conveying line, wherein the conveying line is implemented in a double-walled manner.

Furthermore, US2007/221673a1 discloses a storage container for water-contaminated liquids with a leak detection and retention system comprising: a channel surrounding the tank proximate an outer wall of the tank and for collecting the effluent liquid; a channel drain; a liquid collection vessel; and a detection system for water-contaminated liquids. The channel drain is adapted to transfer liquid collected in the channel to a liquid collection container equipped with a detection system.

US2005/087258a1 discloses a fuel nozzle for a fuel dispensing system having a PFA coating.

CN203259311U discloses a leakage measuring device of a desulfurized gas-gas heat exchanger system comprising a sampling tube. Exhaust gas samples of the gas-gas heat exchanger are collected by means of a leakage measuring device in order to detect a leakage in the heat exchanger.

Disclosure of Invention

The present invention is based on the object of correspondingly alleviating or eliminating at least individual disadvantages of the prior art. The invention is particularly intended to disclose a method for reliably detecting and preventing leaks in double-walled containers.

The present invention provides a method for detecting and preventing leaks in a double-walled container, wherein the double-walled container has an inner wall and an outer wall, wherein a cavity is formed between the inner wall and the outer wall, wherein a positive pressure is generated within the cavity, and wherein in the event of a leak in the inner wall, a gas is supplied to the cavity to maintain the positive pressure within the cavity.

Thereby achieving the above object.

Accordingly, the present invention also provides a container system for storing toxic, corrosive, irritating and/or flammable media. The container system at least comprises:

-a double-walled container having an inner wall and an outer wall, wherein a cavity is formed between the inner wall and the outer wall;

-a compressor, preferably a side channel blower;

-a conduit arranged for conveying gas and for connecting the outer wall to the compressor;

an open/closed loop control device, preferably a control valve, in particular a bypass control valve, for open/closed loop control of the gas throughflow in the line; and

a pressure measuring unit for measuring the pressure in the cavity of the double-walled container.

The above object is also achieved.

In the method of the invention, the medium located inside the double-walled container surprisingly does not flow out of the container if the inner wall leaks, since the absolute pressure in the cavity between the inner wall and the outer wall of the container is greater than the absolute pressure in the container, resulting in a flow from the cavity into the interior of the container through the leakage hole in the inner wall. The interior of the container is a volume closed by the container, wherein the container may be at least partially open at the top or completely closed.

The container system of the present invention comprises a double-walled container having an inner wall and an outer wall with a cavity formed therebetween. The container system further comprises a compressor, preferably a side channel blower, for generating a positive pressure, wherein the compressor is connected to the outer wall of the double-walled container via a line provided for conveying gas. The pressure in the chamber of the container is measured by means of a pressure measuring unit and open-loop or closed-loop control of the gas throughflow in the line is effected by means of an open-loop/closed-loop control device. If the positive pressure in the cavity of the container drops due to a leak, the pressure measuring unit measures the dropped pressure and transmits a pressure signal to the open/closed loop control device. An open/closed loop control means (preferably a control valve, particularly a bypass control valve) then controls the gas flow rate in the line to deliver gas into the chamber in a controlled manner to maintain a positive pressure within the chamber.

According to a preferred embodiment, the double-walled container is supplied with at least one gas, preferably at least one gas and at least one liquid. If the inner wall of the container leaks, gas is advantageously prevented from flowing out of the container because the pressure in the cavity between the inner wall and the outer wall is higher relative to the pressure of the gas within the container.

According to another preferred embodiment, the positive pressure within the cavity is measured, preferably by measuring the pressure of the gas supplied to the double-walled container and measuring the pressure of the gas supplied to the cavity and calculating the difference between these two pressures. Due to the determination of the pressure difference between the gas supplied to the double-walled container and the gas supplied to the cavity, the positive pressure is relative to the pressure in the container, thus ensuring that the pressure in the cavity is higher than the pressure in the container. Therefore, if the inner wall is leaked, the flow direction through the leakage hole always extends from the cavity to the inside of the container, thereby preventing the gas stored in the container from flowing out of the container.

In order to control the positive pressure within the chamber, it is advantageous to control the pressure and/or through-flow of the gas supplied to the chamber such that the positive pressure within the chamber is between 5 mbar and 50 mbar, preferably between 10 mbar and 30 mbar, relative to the pressure inside the double-walled container.

According to a preferred embodiment, the liquid stored in the double-walled container flows out of the container due to a leak in the inner wall and accumulates in the cavity, at the lowest point of the cavity is conveyed via a drain line into a monitoring container, wherein the monitoring container is partially filled with another liquid, preferably water, in particular completely desalinated water or softened industrial water. The monitoring container is therefore connected to the lowest point of the cavity of the double-walled container via a line provided for conveying the liquid. In this way, liquid stored in the container and flowing out of the container through the leakage hole in the inner wall is prevented from accumulating in the cavity, thereby preventing the liquid from flowing out through the outer wall.

It is advantageous to measure the level and/or the temperature and/or the electrical conductivity of the liquid in the monitoring vessel in order to detect a leak in the double-walled vessel. For this purpose, the monitoring container advantageously has a measuring device, in particular a radar measuring device, for measuring the level of the liquid in the monitoring container. It is furthermore advantageous if the monitoring container has a conductivity sensor and/or a temperature sensor, wherein a multi-parameter transmitter for evaluating the measurement results of the conductivity and/or the temperature of the liquid in the monitoring container is preferably provided. This has the advantage that multiple parameters, such as conductivity and temperature, can be simultaneously acquired and monitored using a multi-parameter transmitter to take into account the correlation of the parameters. One such example is the temperature dependence of the electrical conductivity.

If the liquid stored in the container flows out of the container, it is conveyed through the discharge line into a monitoring container which is partially filled with another liquid, so that the level of the liquid in the monitoring container rises. Thus, a leak in the double-walled container can be detected in the monitoring container by means of a measuring device, in particular a radar measuring device, for measuring the level of the liquid in the monitoring container. The liquid stored in the monitoring container has the following advantages: the outflow of the liquid stored in the double-walled container and having a high temperature causes the colder liquid stored in the monitoring container to mix in the monitoring container with the hotter liquid flowing out of the double-walled container, so that the temperature of the liquid mixture is lower than the temperature of the liquid flowing out of the double-walled container. Thus, any measuring device in the monitoring container is protected from overheating.

If the temperature of the liquid stored in the container and the temperature of the liquid stored in the monitoring container differ, a temperature change of the liquid in the monitoring container can be measured by means of a temperature sensor, and a leak in the double-walled container can be detected from this temperature change. The liquid transferred from the cavity of the double-walled container into the monitoring container is mixed with the liquid originally stored in the monitoring container. This mixing of the two liquids results in an average temperature of the liquid mixture being formed, wherein the average temperature is different from the temperature of the liquid originally partially filling the monitoring container. This temperature change allows detection of leaks in double-walled containers. If large leakage holes are present in the inner wall, the temperature in the monitoring container can be additionally controlled by means of temperature measurement and cooling of the monitoring container.

If the electrical conductivity of the liquid stored in the container and the electrical conductivity of the liquid stored in the monitoring container differ, a change in the electrical conductivity of the liquid in the monitoring container can be measured by means of the conductivity sensor, on the basis of which a leak in the double-walled container can likewise be detected. The electrical conductivity of the liquid stored in the monitoring container changes due to the additional supply of liquid transported from the cavity of the double-walled container into the monitoring container. This change in conductivity enables detection of a leak in a double-walled container.

According to a preferred embodiment, an alarm is triggered when a predetermined limit value for monitoring the level and/or temperature and/or conductivity of the liquid in the container is reached. When the alarm is triggered, the operator of the double-walled container is informed of the occurrence of a leak in the inner wall of the container, so that the measures required to cope with the inner wall leak can be taken in time.

In order to prevent overflow of the monitoring container, it is advantageous if, as soon as the level of the liquid in the monitoring container reaches a limit value, the monitoring container is emptied via a bottom discharge valve into another container, which is preferably an Intermediate Bulk Container (IBC). This has the advantage that the liquid flowing out of the double-walled container is not in contact with the environment.

According to a preferred embodiment, the container system of the invention comprises a flow meter for measuring the flow rate of the gas supplied to the cavity of the double-walled container. In the case of a leak, since the gas throughflow is controlled open/closed loop by means of an open/closed loop control device, preferably by at least partially closing a control valve, in particular a bypass control valve, so that the throughflow of gas in the line from the compressor to the chamber is increased, a flow rate change can be measured by means of a flow meter and a leak in the double-walled container can be detected on the basis of this change.

To protect the double-walled container from the corrosive media stored therein, the inner and outer walls are lined with a barrier layer, preferably comprising perfluoroalkoxy Polymer (PFA). Such lining of the container walls prevents the container from leaking holes due to corrosive media (e.g., strong acids or bases) located in the container.

According to a preferred embodiment, the double-walled vessel of the vessel system is used as an acid condensate tank in a desulfurization process, preferably a Wet Sulfuric Acid (WSA) process. Since the sulfuric acid is stored in the acid condensate tank, it is necessary to prevent the sulfuric acid from flowing out to the environment due to leakage. The container system of the present invention prevents these types of leaks caused by corrosive media such as sulfuric acid, and detects leaks in the inner wall of the double-walled container to prevent leakage in the outer wall and thus prevent leakage of sulfuric acid from the double-walled container.

Drawings

The invention will be described in more detail hereinafter with reference to non-limiting exemplary embodiments shown in the drawings.

FIG. 1 shows a flow diagram of a container system of the present invention in which leaks in a double-walled container are detected and prevented.

Detailed Description

Fig. 1 shows a flow diagram of a container system 1 of the invention comprising a double-walled container 2. According to the embodiment shown, the double-walled container 2 is used as an acid condensate tank in a Wet Sulfuric Acid (WSA) process. Sulfuric acid is produced by means of a WSA process known, for example, from DE68912766T2 in pipes which are arranged mainly vertically and in an acid condensation tank, in which WSA process the sulfuric acid vapor condenses and the droplets of sulfuric acid are collected in special filters. In this case, the gas-containing sulfuric acid is supplied to the conduit from below at a temperature above the dew point of the sulfuric acid and is cooled to a temperature at which the sulfuric acid condenses, while it flows upwards in the conduit. An aerosol filter for separating the condensed sulfuric acid is fastened to the upper end of the pipe.

In the embodiment shown, the double-walled container 2 is a closed container having an inner wall 3 and an outer wall 4, wherein a cavity 5 is formed between the inner wall 3 and the outer wall 4. The inner wall 3 and the outer wall 4 are lined with a barrier layer of perfluoroalkoxy Polymer (PFA) to increase resistance to a liquid stored in the container 2 which consists at least in part of sulfuric acid.

In the embodiment shown, sulfur-containing off-gas is conveyed via supply line 6 to the interior of the closed double-walled vessel 2 to condense sulfuric acid vapor in the vessel 2. The pressure measuring unit 7 measures the pressure of the supply line 6, wherein the pressure corresponds to the pressure inside the container 2. Gas is supplied to the chamber 5 of the vessel 2 via a line 8 connected to the chamber 5. The gas is subjected to a positive pressure by means of a compressor, which is realized in the form of a side channel blower 9 and is connected to the line 8. In addition, a flow meter 10 for measuring the flow rate and a pressure measuring unit 11 for measuring the pressure in the line 8 are arranged on the line 8. By means of a pressure measurement in the supply line 6 by the pressure measuring unit 7 and a pressure measurement in the line 8 by the pressure measuring unit 11, a pressure difference between the interior of the closed container 2 and the cavity 5 is determined, wherein a signal of the determined pressure difference is transmitted to an open/closed loop control device, which in the embodiment shown is realized in the form of a bypass control valve 12. During normal operation, a constant positive pressure of 20 mbar relative to the pressure inside the container 2 is generated in the cavity 5 of the container 2 by the side channel blower 9 and by means of the pressure control by the bypass control valve 12. The side channel blower 9 is also deactivated if there is no positive pressure in the interior of the vessel 2 relative to the environment, for example no supply of sour off-gas.

If the inner wall 3 leaks, gas flows from the chamber 5 into the interior of the container 2, so that the positive pressure in the chamber 5 falls. This results in an increase in the gas flow rate in the line 8, which increase is detected by means of the flow meter 10 and triggers an alarm. The pressure in the line 8 simultaneously drops, wherein the bypass control valve 12 compensates for the pressure drop.

In the embodiment shown, the double-walled container 2 has a discharge line 13 of Polytetrafluoroethylene (PTFE) at the lowest point of the cavity 5. The discharge line 13 is connected to a monitoring vessel 14, which monitoring vessel 14 is filled to approximately 70% with softened industrial water. The monitoring container 14 has a radar measuring device 15 for measuring the level of the liquid stored in the monitoring container 14. In addition to the radar measuring device 15, the monitoring container 14 also has a liquid level limit indicator 16 for triggering an alarm as soon as a limit value of the liquid level is reached. The monitoring container 14 in the embodiment shown also has a conductivity sensor 17 and a temperature sensor 18 for measuring the conductivity and the temperature, respectively, of the liquid stored in the monitoring container 14. In order to ensure reliable operation of the conductivity measurement, the last part of the conductivity sensor 17, which is realized in the form of a probe in the embodiment shown, must always be immersed in the liquid. The evaluation of the conductivity measurements and the temperature measurements is carried out by means of a multi-parameter transmitter, which is not shown in fig. 1.

If in the embodiment shown a leakage occurs in the inner wall 3, the liquid stored in the container 2, which liquid at least partly consists of sulphuric acid, flows out through the leakage hole and collects in the cavity 5, wherein the liquid flows to the lowest point of the cavity 5 under the influence of gravity. The liquid is transported at the lowest point via the drain line 13 into the monitoring container 14, wherein the liquid is mixed with the softened industrial water stored in the monitoring container 14. Due to the constant cooling of the walls of the monitoring container 14, the temperature of the softened industrial water stored therein is about 30 ℃. The temperature of the liquid mixture in the monitoring vessel 14 increases as the softened industrial water mixes with the warmer liquid being transferred from the vessel 2 into the monitoring vessel 14. This temperature rise is measured by means of the temperature sensor 18 and a corresponding signal is transmitted to the multi-parameter transmitter. The multi-parameter transmitter evaluates the signal of the temperature increase and triggers an alarm once the temperature of the liquid in the container 14 is monitored to reach 50 ℃.

The mixing of the softened industrial water with the liquid from the container 2 results not only in a change in the temperature of the liquid mixture, but also in a change in its electrical conductivity. This change in conductivity is measured by means of the conductivity sensor 17 and a corresponding signal is transmitted to the multi-parameter transmitter. The multi-parameter transmitter evaluates the conductivity increase signal and likewise triggers an alarm.

The liquid conveyed into the monitoring container 14 causes a rise in the level of the liquid mixture stored in the monitoring container 14, wherein the rise in the level is measured by the radar measuring device 15 and a corresponding signal is transmitted to the device for evaluating the measurement result. The rise in the liquid level enables detection of a leak in the inner wall 3 of the container 2, so that measures required to cope with the leak in the inner wall 3 can be taken in good time. The level limit indicator 16 triggers an alarm once the level of the liquid reaches about 90% of the height of the interior volume of the monitoring container 14. When an alarm is triggered, the monitoring container 14 is emptied into an Intermediate Bulk Container (IBC)19 arranged below the monitoring container 14 through a bottom drain valve 20 to prevent liquid flowing out of the container 2 being transported into the monitoring container 14 from coming into contact with the environment.