MXPA96004628A - Hazardous material containment system - Google Patents

Abstract

The present invention relates to an apparatus for containing hazardous material leaks from a transport container having a first valve that allows dangerous material to flow into and out of the transport container, the apparatus being characterized in that it comprises: a removable dome having a open bottom shaped to be placed on a portion of the container including the first valve, the dome is adapted to be placed on the container portion during at least one of the filling and discharge of hazardous material through the first valve; sealing means to create an airtight seal on the dome and the container so that any leakage of hazardous material from the container's portion will flow inside the dome in a manner that prevents leakage of the hazardous material in the surrounding environment; medium, in communication to the vacuum with the interior of the dome, to maintain a vacuum at least partially inside the dome to neutralize the dangerous material, the first detector means, mounted from the dome, to detect the presence of the dangerous material and to generate a first control signal in response to it, and a safety valve controlled remotely, connected to a first valve, the interruption valve is coupled to the first detector means and that responds to the interruption of flow of the dangerous material when the first control signal is generated due to a leak of dangerous material inside the

Description

SYSTEM. OF CONTAINMENT OF DANGEROUS MATERIAL BACKGROUND OF THE INVENTION The present invention relates generally to the containment systems of hazardous material, and more particularly to an apparatus for containing hazardous material when it is loaded into or discharged from a container for bulk transport such as a tank truck or a rail tank wagon. The transportation and handling of hazardous materials, such as chlorine in its liquid or gaseous forms, presents many well-known health and environmental risks. Despite these risks, many of the methods currently used to control a leak in such conditions are prohibitively expensive, or ineffective in certain circumstances. As a result, system failures associated with bulk transport containers have produced many leaks of harmful hazardous material. A device currently used to control leaks of hazardous material is an excess flow check valve. Such a valve stops the flow of material from a container when the flow rate is above a predetermined limit, known as the reference point of the excess flow check valve. Although overflow check valves are effective in many circumstances, a large discharge can still occur if the flow velocity of a leak is less than the reference point of the excess flow check valve. Another device used to control leaks of hazardous material is a shut-off valve or stopcock mounted and activated remotely. Such a valve can be used by itself, or in combination with one or more detectors of dangerous materials. If a leak is detected, the detectors generate a signal that causes the remote valve to close. A major disadvantage of this arrangement is that a leak can evade the location of a detector, and thus pass undetected for some period of time. Also, there is no way to neutralize the material discharged before the remote valve is closed. Finally, the most effective of the prior techniques for controlling leakage of hazardous material is the complete confinement of a transport container within an environmental structure sealed. Detectors and shut-off valves can be provided within the structure itself, allowing the detection and complete containment of a hazardous material leak. One of the disadvantages of such an arrangement is that in the case of a discharge of hazardous material, the volume of air that must be controlled (absorbed or neutralized) is very large. Therefore, the neutralization of the leaked material requires a very large and expensive control system. Environmentally sealed structures are also very expensive and immovable. Therefore, users of hazardous material do not always load or unload the material in or from containers with transport in a safe manner.

BRIEF DESCRIPTION OF THE INVENTION Accordingly, an object of the present invention is to provide a portable apparatus for the containment of dangerous material leaks that occur when a transport container is loaded or unloaded. The present invention includes a removable dome placed on the inlet or outlet valve of the transport container, a means for maintaining a partial vacuum within the dome, a vacuum gauge, a hazardous material detector, and a remotely controlled valve responsive to the signals generated by the vacuum gauge and the hazardous material detector so that the flow of material can be stopped if a leak or loss of vacuum is detected.

The additional objects and advantages of the invention are set forth in the description that follows, and in part they will be obvious from the description or can be understood by the practice of the invention. The objects and advantages of the invention can be achieved and obtained by means of the instrumentalisations and combinations particularly pointed out in the claims.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate schematically a preferred embodiment of the invention, and together with the general description given above and the detailed description of the preferred embodiment given below, serve to explain the principles of the invention. Figure 1 is a perspective view showing a portion of the present invention as used with a rail tank wagon. Figure 2 is a schematic cross-sectional view showing a portion of the present invention.

Figure 3 is a schematic cross-sectional view of the present invention as used with a separate evaporator and control device.

DESCRIPTION OF THE PREFERRED MODALITY Reference will now be made in detail to the preferred embodiment of the invention, which is a containment system for hazardous material. An example of the preferred embodiment is illustrated in the accompanying drawings.

In this description, gaseous and liquid Cl2 was used as an example of a controlled and contained hazardous material by the present invention. Although the invention will be described in conjunction with that preferred embodiment, it should be understood that it is not intended to limit the invention to a preferred embodiment, or to a specific hazardous material. On the contrary, it is intended to cover the alternatives, modifications, and equivalents that may be included within the scope of the invention as defined by the appended claims. Referring now to the drawings, where similar components are designated by similar reference units, Figure 1 is a perspective view showing a portion of a hazardous material containment system (HMCS) according to a preferred embodiment of the invention. present invention. The HMCS is designated by the general reference numeral 20. In the preferred embodiment, the HMCS 20 is in the form of a removable translucent fiberglass dome 22 having a lower seal 24 designed to fit over a transport container 26. The dome 22 can be fastened on the transport container 26 by means of the clamps 30, or by any other means for securing the dome 22 to the transport container 26. The seal 24 and the clamps 30 create an airtight seal between the dome 22 and the container for I transport 26. The dome 22 also includes one or more doors 28, preferably made of self-sealing fabric, to allow access to the interior of the dome 22. The dome 22 may also include one or more transparent windows 29, which allow it to be seen the interior of the dome 22. Preferably, the windows 29 are made of a soft material that can be cut with a razor in the case of an emergency. Referring now to Figure 2, a schematic cross-sectional view of the HMCS 20 and the transport container 26 is shown. The transport container 26 includes a back pressure angle valve 30 used to load or discharge a hazardous material (such as Cl2) to or from the transport container 26. The counter-pressure angled valve 30 is typically connected to an excess flow check valve 32, which is used to prevent rapid leakage of the transport container 26. The dome 22 includes a automatic or remotely controlled shut-off valve 34 responsive to signals generated by one or more hazardous material detectors 36 or vacuum gauges 38 mounted within the dome 22. The valve 34 may also be sensitive to signals generated by other sources to be discussed later.

The detectors 36, gauges 38, and other signal sources are all coupled to the valve 34 via the signal conductor 58. The dome 22 also includes an air inlet butterfly valve 44, and may include a television camera 46, which allows the inside of the dome to be viewed from a distance 22. During the download process, the material flows from the transport container 26 through the valves 30, 32 and 34, and into an internal flow tube or hose 40. The material then flows from the dome 22 via an external flow tube or hose 42. A ventilation hose 43 is also connected to a dome 22. The ventilation hose 43 is used to partially evacuate the interior of the dome 22, and to remove any vapors of hazardous material leaked from inside the dome 22. Referring now to Figure 3 , the use of the dome 22 in combination with an environmentally sealed evaporating platform 5 and the scrubber or scrubber 60 is shown. The evaporating platform 50 is used to change the Cl 2 from its liquid phase to its gaseous phase. The material flows through the hose • '. external flow 42 and to a tube or flow hose of the evaporator 48 inside the evaporator platform 50. The ventilation hose 43 is connected to the interior of the evaporator platform 50, placing the interiors of the platform 50 and the dome 22 in communication to the vacuum The evaporator platform 50 includes an evaporator 52 and a container for the evaporator 54, both of which are well known to those skilled in the art. Also included within the platform 50 are one or more hazardous material detectors 36 and the vacuum gauges 38. The detectors 36 and the pressure gauges 38 0 operate identically to those described above with respect to Figure 2, and are also connected to the signal conductor 58. A ventilation hose 56 is connected to the interior of a platform 50, and is used to position the interior of the platform 50 in vacuum communication with a control device 60. In a preferred embodiment, the control 60 is a ferrous gas scrubber capable of absorbing gaseous Cl2. The gaseous control device 60 operates under negative pressure, which creates a partial vacuum within the evaporator platform 50 and the dome 22. The maximum vacuum pressure provided by the control device 60 is preferably 10 inches of water in relation to the environmental pressure. By generating this vacuum, the control device 60 draws any vapors of hazardous material escaped into the dome 22 or the platform 50. The control device 60 also includes a status monitor 62, which is coupled to the signal conductor 58. In the In case of a failure or malfunction within the control device 60, the status monitor 62 will generate a control signal. This control signal is transmitted over the signal conductor 58 to the signal valve (see Figure 2), and causes the valve 34 to close, or prevent the valve 34 from opening. A predetermined vacuum level should be maintained within dome 22 and on platform 50 for valve 34 to open. Otherwise, one or more vacuum gauges 38 will generate a control signal, transmitted over the signal conductor 58, which will either close the valve 34, or prevent the valve 34 from opening.

The dome 22 allows rapid detection of the leak due to the relatively small space surrounded by the dome 22 and the container 26. Any leaky material will quickly reach a detector 36 within the dome 22 or the platform 50. The detectors 36 will then generate a signal of control, transmitted on the signal conductor 58, which closes the valve 34, as described above. This rapid response limits the volume of material escaped from the container 26. Therefore, the control device 60 needs only enough energy to absorb or deactivate the largest amount of the hazardous material that could have escaped before the valve 24 closes. The detectors 36 can be verified either manually or automatically to determine when all the hazardous material that escaped has been removed. After the concentration of the hazardous material is reduced to acceptable levels, the source of the leak can be corrected. The operation of the dome 22, the platform 50 and the control device 60 can be controlled remotely through the use of a computing device or controller 70 such as a microcomputer or a dedicated microcontroller. The HMCS 20 can also incorporate a visual and / or audible alarm system that indicates when a leak, loss of vacuum, or control device failure has occurred.

It should be understood by those skilled in the art that the evaporating platform 50 need not be used during the operation of the present invention. For example, during a charging process, the flow hose 42 can be connected directly to a source of liquid Cl2, and the ventilation hose 43 can be connected directly to the control device 60 and the dome 22., an evaporator may not be necessary when a hazardous material other than Cl2 is discharged. However, the HMCS 20 must always be used with the control device 60 so that any leaked material can be absorbed or deactivated. The present invention has been described in terms of a preferred embodiment. The invention, however, is not limited to the embodiment illustrated and described. On the contrary, the scope of the invention is defined by the appended claims. It is noted that in relation to this date, the best method known by the applicant to carry out the aforementioned invention, is the conventional one for the manufacture of the objects to which it relates. Having described the invention as above, property is claimed as contained in the following:

Claims (22)

1. An apparatus for containing dangerous material leaks from a transport container, the transport container has a first valve that allows the hazardous material to flow into and out of the transport container, the apparatus is characterized in that it comprises: a removable dome having a open bottom formed to fit over the container; sealing means to create an airtight seal between the dome and the container; means, in communication with the vacuum inside the dome, to maintain at least a partial vacuum inside the dome and to neutralize the dangerous material; first detector means, mounted inside the dome, to detect the presence of the dangerous material and to generate a first control signal in response thereto; and a remotely controlled shut-off valve connected to the first valve, coupled to the first detector means, and which is sensitive to interruption of the flow of the hazardous material when the first control signal is generated.

2. The apparatus according to claim 1, characterized in that it also includes second detector means, mounted inside the dome, to detect a partial vacuum loss and to generate a second control signal in response to this.

3. The apparatus according to claim 2, characterized in that the shut-off valve is also sensitive to the interruption of the flow of the dangerous material when the second control signal is generated.

4. The apparatus according to claim 1, characterized in that it also includes a hose, connected to the remotely controlled valve and extending through the dome, to direct the flow of material between the transport container and a second container external to the dome .

5. The apparatus according to claim 4, characterized in that the second container is an evaporator.

6. The apparatus according to claim 5, characterized in that the second container is mounted inside a third environmentally sealed container.

7. The apparatus according to claim 6, characterized in that it also includes means, in vacuum communication with the interior of the third container, to maintain a partial vacuum inside the third container and to neutralize the dangerous material.

8. The apparatus according to claim 7, characterized in that it also includes means, mounted within the third container and coupled to the remotely controlled valve, to detect the presence of the hazardous material to generate a third control signal in response thereto.

9. The apparatus according to claim 8, characterized in that the shut-off valve is also sensitive to the interruption of the flow of the dangerous material when the third control signal is generated.

10. The apparatus according to claim 1, characterized in that the means for maintaining a partial vacuum within the dome and for neutralization is a scrubber or scrubber that operates under negative pressure.

11. The apparatus according to claim 10, characterized in that the scrubber or gas scrubber further includes means for generating a fourth control signal in response to a malfunction of the scrubber or gas scrubber.

12. The apparatus according to claim 11, characterized in that the shut-off valve is also sensitive to the interruption of the flow of the hazardous material when the fourth control signal is generated.

13. The apparatus according to claim 7, characterized in that the means for maintaining a partial vacuum within the third container and for neutralization is a scrubber or gas scrubber that operates under negative pressure.

14. The apparatus according to claim 13, characterized in that the scrubber or gas scrubber further includes means for generating a fifth control signal in response to a malfunction of the scrubber or gas scrubber..

15. The apparatus according to claim 14, characterized in that the shut-off valve is also sensitive to interruption of the flow of the hazardous material when the fifth control signal is generated.

16. The apparatus according to claim 1, characterized in that the dome is made of translucent material.

17. The apparatus according to claim 16, characterized in that the translucent material is glass fiber.

18. The apparatus according to claim 1, characterized in that the dome includes a door.

19. The apparatus according to claim 18, characterized in that the door is made of self-sealing fabric.

20. The apparatus according to claim 1, characterized in that the dome includes a transparent window.

21. The apparatus according to claim 20, characterized in that the window can be cut with a knife.

22. The apparatus according to claim 1, characterized in that it also includes a television camera mounted inside the dome.