Abstract:
A filter-valve assembly for exhausting fumes from a liquid container includes a mounting-valve assembly having a valve poppet that is moved to an open position in response to a filter-cartridge assembly being attached to a valve-assembly housing by a filter-cartridge attaching mechanism and is moved to a closed position in response to the filter-cartridge assembly being detached from the valve housing. The filter-cartridge assembly includes a coalescing filter and a carbon filter, with an orientation-activated capsize valve located in a coalescing-filter housing for preventing spills upon capsizing and litmus-like material at an exit opening of a carbon-filter housing for indicating a need to replace the carbon filter.

Description:
BACKGROUND OF THE INVENTION 
     This invention relates generally to the art of hazardous-waste disposal and more specifically to a system for protecting people from fumes given off by discarded chemical liquids. 
     Many laboratories, both industrial and academic, discard large amounts of hazardous chemical liquids on a continuous basis. Such hazardous liquids are often continuously drained into hazardous-liquid containers through tubes, and when the hazardous-liquid containers are filled they are emptied. Because such collection containers must be vented to allow proper drainage, they often give off noxious gases, which are released into the atmosphere thereby polluting air breathed by personnel working around the hazardous-liquid collection containers. In addition to being offensive, these fumes can also be flammable, and therefore quite dangerous. 
     Thus, it is an object of this invention to appropriately clean fumes and gases escaping from discarded liquids in hazardous-liquid collection containers. 
     Another dangerous problem related to such hazardous-liquid collection containers is that when they are capsized the hazardous liquids therein escape through exhausts and other openings. Thus, it is another object of this invention to provide an exhaust-opening assembly for a hazardous-liquid collection container that not only reliably cleans noxious fumes escaping from the containers but which also prevents the hazardous liquids themselves from spilling from the containers if they are capsized. 
     It is still another object of this invention to provide a filter assembly for a hazardous-liquid collection container that informs users when carbon of a filter thereof is exhausted. 
     Further, it is an object of this invention to provide a filter-valve assembly for hazardous-liquid collection containers that does not allow passage of noxious fumes when a filter-cartridge assembly thereof is removed. 
     SUMMARY OF THE INVENTION 
     According to principles of this invention, an exhaust-opening assembly for exhausting fumes from a hazardous-liquid collection container includes a filter-valve assembly that includes a valve poppet that is moveable to an open position in response to a filter-cartridge assembly being attached to a mounting-valve-unit housing by a filter-cartridge attaching mechanism and that is allowed to be moved by a resilient biasing device to a closed position in response to the filter-cartridge assembly being detached from the mounting-valve-unit housing. 
     In one embodiment, the valve poppet has fingers extending along an exit passage, which engage a neck portion of the filter-cartridge assembly when the filter-cartridge assembly is screwed into the exit passage to move the valve poppet away from a valve seat. When the filter-cartridge assembly is removed, the resilient biasing device presses the valve poppet against the valve seat for closing the exit passage. 
     The mounting-valve-unit housing extends about a substantial outer portion of the filter-cartridge assembly for protecting the filter-cartridge assembly upon the hazardous-liquid collection container capsizing. 
     The filter-cartridge assembly includes an orientation-responsive shut-off valve to prevent flow of hazardous liquids through filter-cartridge housings upon capsizing and litmus-like material, which can be seen from outside the housings, to inform users when carbon of a carbon filter element is exhausted. 
     In a preferred embodiment, the filter-cartridge assembly is divided into a first-stage coalescing filter and a second-stage carbon filter, with the orientation-responsive valve being in a coalescing-filter housing and the litmus-like material being at an exit end of a carbon-filter housing. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention is described and explained in more detail with reference to the drawings. The described and drawn features can be used individually or in preferred combinations in other embodiments of the invention. The foregoing and other objects, features and advantages of the invention will be apparent from the following more particular description of the invention, as illustrated in the drawings in which reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating principles of the invention in a clear manner. 
     FIG. 1 is an isometric view of a prior art hazardous-liquid collection container; 
     FIG. 2 is a side, partially cutaway, view of a hazardous-liquid collection container with a filter-valve assembly of this invention attached thereto, with portions thereof removed for simplicity; 
     FIG. 3 is an enlarged segmented view of a hazardous-liquid collection container with a filter-valve assembly of this invention attached thereto, the filter-valve assembly being shown in partial cross section; 
     FIG. 4 is a side view of a mounting adaptor, which is part of the filter-valve assembly of FIG. 3; 
     FIG. 5 is a top view of the mounting adaptor of FIG. 4; 
     FIG. 6 is a side view of a valve poppet of the filter-valve assembly of FIG. 3; 
     FIG. 7 is a top view of the valve poppet of FIG. 6, and 
     FIG. 8 is a view similar to FIG. 3 of a modified embodiment. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     A hazardous-liquid collection container  10  of a type used in the prior art is depicted in FIG.  1 . As can be seen in FIG. 1 this collection container includes a cover  12  that can be opened by movement of a handle  14  and a liquid inlet nipple  16  for being attached to a hose, or tube, for allowing hazardous liquids to drain into a tank  18  of the collection container  10 . The hazardous liquids in the tank  18  give off noxious gases, which develop pressure and escape from the tank  18  at a vent and around the cover  12 , thereby contaminating surrounding air, both being objectionable and dangerous to personnel. 
     FIG. 2 depicts a similar hazardous-liquid collection container  10 ′ having a filter-valve assembly  20  of this invention attached thereto. In this regard, in FIG. 2 the filter-valve assembly  20  is shown in a simplified form, with parts removed, but it is shown in more detail in the enlarged view of FIG.  3 . The filter-valve assembly  20  serves as an exhaust, or vent, opening assembly. 
     The filter-valve assembly  20  basically includes a filter-cartridge assembly  22  and a mounting-valve assembly  24 . 
     The mounting-valve assembly  24  includes a mounting adaptor  26  and a mounting-valve unit  28 . 
     With regard to the mounting adaptor  26 , this element is essentially a block of aircraft aluminum defining a central entrance bore  30  and four screw bores  32 . As can be seen in FIG. 3, the mounting adaptor  26  has a curved contoured side  34  for conforming to a curved contour of an upper shoulder of the collection container tank  18 ′. Protruding from a lower side  34  of the mounting adaptor  26  is a bottom plug portion  36  through which the central entrance bore  30  passes. 
     The mounting-valve unit  28  mainly includes a base plate  38 , a mounting-valve-unit housing  40 , a mounting-valve poppet  42  and a bias spring  44 . 
     The base plate  38  is basically a round disc of TEFLON having an outer diameter similar to an outer diameter of the mounting adaptor  26  (see FIG.  5 ), defining a central entrance bore  46  that aligns with the central entrance bore  30  of the mounting adaptor  26  and having bolt holes  48 . As can be seen in the drawings, in the assembled condition, the base plate  38  is screwed to a lower end of the mounting-valve-unit housing  40  by screws in the boltholes  48 . The somewhat resilient TEFLON forms a good seal with the mounting-valve-unit housing  40 , while at the same time the TEFLON prevents the base plate  38  from becoming inadvertently adhered to the mounting-valve-unit housing  40  by adhesive-like vapors from chemicals in the tank  10 ′. 
     The mounting-valve-unit housing  40  is of aircraft aluminum coated inside and out with TEFLON. The aircraft aluminum gives this part strength and provides chemical resistance. The TEFLON coating also helps protect the mounting-valve-unit housing  40  from chemical attack, but in addition makes it easy to clean and improves its appearance. 
     The base plate  38  and the mounting-valve-unit housing  40  define a mounting-valve cavity  50  in which the mounting-valve poppet  42  and the bias spring  44  are located. This mounting-valve poppet  42  is likewise of aluminum covered with a layer of TEFLON. The bias spring  44  is held at its lower end by a protrusion on the base plate  38  and at its upper end by a protrusion on the mounting-valve poppet  42 , with both protrusions extending into a center of the coiled bias spring  44 . The bias spring  44  urges the mounting-valve poppet upwardly toward a valve seat  52  formed by the mounting-valve-unit housing  40 , with an O-ring on the mounting-valve poppet  42  actually making contact with the valve seat  52 . The mounting-valve poppet  42  is held stabilized in the center of the mounting-valve cavity  52  by fingers  54  thereof (see FIGS. 6 and 7 for more detail), which extend into an exit bore  56  defined by the mounting-valve-unit housing  40  leading out of the mounting-valve cavity  50 . 
     A two-way beveled, threaded bolt  58  is screwed into the entrance bores  30  and  46  of the mounting adaptor  26  and the base plate  38  respectively when the filter-valve assembly  20  is assembled as depicted in FIG.  3 . 
     The filter-cartridge assembly  22  is of a type sometimes referred to as a two-stage capsule filter; comprising a male threaded neck portion  60  for engaging female threads in an upper end of the exit bore  56  of the mounting-valve-unit housing  40 . A bore of the neck portion  60  leads into a first-stage-filter housing  67  of a first-stage filter  62  of the filter-cartridge assembly  22 . The first-stage-filter housing  67  is of a translucent polypropylene. On top of the first-stage filter  62  is a detachable second-stage filter  64  that, in the depicted embodiment, can be screwed onto an upper neck  66  of the first-stage filter  62 . The description in U.S. Pat. 5,284,997 to Spearman et al. describes a similar filter assembly of this general type and the teachings of that patent are incorporated herein by reference. 
     Briefly, the first-stage filter  62  comprises a coalescing filter, in which small liquid droplets in a gaseous mixture combine to form larger droplets that are a sufficient size to accumulate in the first-stage filter housing  67 , which accumulation can be seen through the translucent first-stage-filter housing  67 . A coalescing filter member  68  and other filter members serve for causing the liquid accumulation. 
     The second-stage filter  64  comprises a one-piece second-stage filter housing  70 , of polypropylene, containing granular carbon  72  held between downstream and upstream porous filter members, which prevent dust from getting into the carbon  72  and help hold the carbon  72  in place. As gaseous mixtures flow through the second-stage filter  64 , the carbon  72  therein removes hazardous solvents in the gaseous mixture, thereby allowing gases, stripped of hazardous solvents, to discharge into the atmosphere. Thus, the carbon second-stage filter  64  removes hazardous solvents from the gaseous mixtures by retaining them within the carbon filter while the coalescing first-stage filter  62  separates droplets to facilitate removal of the hazardous solvents by the carbon filter. 
     However, the filter-cartridge assembly  22  is modified from those of the general type. Within the first-stage filter housing  67 , at a downstream end of the coalescing filter member  68  (the top end as viewed in FIG.  3 ), there is a capsize-activated shut-off disc  74 . If the tank  18 ′ of the collector container  10 ′ should capsize, or be turned over, downward gravity acting on the shut-off disc  74  would be lessened and the shut-off disc  74  would be driven by pressure and/or gravity against a valve seat  76  formed on an interior surface of the first-stage filter housing  67  about a bore  78  passing through the upper neck  66 . Thus, flow of liquid from the tank  18 ′ through and out of the first-stage filter  62  would be prevented by the orientation/capsize-activated shut-off disc  74  being seated on the valve seat  76 . 
     A litmus-like material  78  is located at the downstream end of the second-stage filter  64  (the top end as viewed in FIG. 3) through which gases pass after the gases have passed through the granular carbon  72 . If the granular carbon  72  has become exhausted, it removes fewer of the hazardous solvents and chemicals in gaseous mixtures and these solvents are then reacted to by the litmus-like material  78  by thereby changing in appearance (such as changing color). Thus, the color of the litmus-like material indicates to a user if it is time to replace the second-stage filter  64 . It should be understood that the term “litmus-like” is used here to indicate any material that provides a visual indication of a presence of a particular substance. 
     Describing now operation of the filter-valve assembly  20 , it will be first assumed, for ease of description only, that the filter-valve assembly is to be retrofitted to a prior-art hazardous-liquid collection container  10  of the type shown in FIG. 1 (normally, however, a filter-valve assembly of this invention will be installed on a collection container when the collection container is manufactured and not retrofitted to an existing container). Any vent in the tank  18  would be covered. Further, if such a retrofit were carried out, the liquid-drain nipple  16  would be removed from the tank  18  and a larger hole would be bored into the tank at the hole left by this removal. The bottom plug portion  36  of the mounting adaptor  26  would then be inserted into this hole and the mounting adaptor  26  attached to the modified tank  18 ′ by an adhesive sealant and the four self-tapping stainless-steel screws (coated with a sealant adhesive) passing through the screw bores  32 . The adhesive sealant would ensure a securely sealed base for attaching the mounting-valve unit  28  to the tank  18 ′. It is actually preferable that the hole in the tank  18 ′ be placed further radially outwardly on the tank  18 ′, more on its rounded shoulder, as shown in FIG. 3, and this is where it would normally be placed on a new manufacture. The curved, contoured lower surface of the mounting adaptor  26  is shaped to fit that portion of the tank  18 ′ on which it is mounted. 
     The mounting-valve unit  28  is first assembled by placing the mounting-valve poppet  42  into the mounting-valve cavity  50 , with the O-ring thereon, so that the fingers  54  of the mounting-valve poppet extend up into the exit bore  56  and then placing the bias spring  44  between the base plate  38  and the mounting-valve poppet  42 . The base plate  38  is then screwed to a lower end of the mounting-valve-unit housing  40 . The O-ring of the mounting-valve poppet  42  is biased against the valve seat  52 . The base plate  38  is then attached to the mounting adaptor.  26  by the two-way beveled bolt  58 , the beveled bolt being screwed into the top end of the entrance bore  30  of the mounting adaptor  26  and the bottom end of the entrance bore  46  of the base plate  38 , so that the attached mounting-valve-unit housing  40  is screwed onto a top end of the two-way beveled bolt  58 . 
     In this configuration, before the filter-cartridge assembly  22  is attached to the mounting-valve assembly  24 , the mounting-valve poppet  42 , which is seated on the valve seat  52 , prevents both gases and liquids from passing through the exit bore  56 . 
     However, when the filter-cartridge assembly  22  is attached to the mounting-valve assembly  24  by the neck portion  60  of the first-stage filter housing  67  being screwed into an upper end of the exit bore  56 , an outermost end of the neck portion  60  comes into contact with the fingers  54  of the mounting-valve poppet  42  and urges the mounting-valve poppet  42  away from the valve seat  52 , thereby moving the mounting-valve poppet to an open position in which gases can flow about the mounting-valve poppet  42  out the exit bore  56  through the filter-cartridge assembly  22 . The filter-valve assembly  20  is now activated, or armed. 
     Should the hazardous-liquid collector container  10 ′ be capsized, or inverted, the capsize-activated shut-off disc  74  will be automatically moved to the valve seat  76  by gravity and/or pressure, thereby preventing liquid from flowing to outside atmosphere through the filter-cartridge assembly  22 . Similarly, the filter cartridge assembly  22  will be protected against breaking off by the high aluminum wall of the mounting-valve-unit housing  40  that extends about the lower end of the first-stage filter  62 . 
     The litmus-like material  78 , which can be observed through a translucent plastic disk  79  will inform user personnel when the granular carbon  72  is exhausted and the second-stage filter must be replaced. 
     It should be noted that the filter-valve assembly  20  can still be used in the manner of the liquid-drain nipple  16  in the prior-art collector container  10  of FIG. 1 by placing a liquid-drain nipple  80  in the wall of the mounting-valve-unit housing  40  below the point at which the mounting-valve poppet  42  seats on the valve seat  52 . Thus, liquid can still be drained into the tank  18 ′ through the same hole as it was drained into the tank before the liquid-drain nipple  16  of the prior-art collector container  10  was replaced by the filter-valve assembly  20 . In one embodiment of the invention there are actually two liquid-drain nipples  80 ′ (see FIG. 8) feeding into the mounting valve cavity  50  space at an angle of  180  from one another so that more than one tube can drain into the tank  18 ′. In another embodiment they are spaced 45° from one another. It will be understood by those of ordinary skill in the art that even more nipples could be included for draining chemicals into the tank  18 ′ via the mounting-valve cavity  50 . In one embodiment the nipple  80  is a female attachment member of a quick-connect/disconnect. It should be noted that the filter-valve assembly  20  is serving as the vent for the hazardous-liquid collection container  10 , but that it can only vent when the filter-cartridge assembly is attached. 
     Again, although the filter-valve assembly was discussed above in the context of a retrofit, it is normally installed on a collection container during manufacturing as an original component. Further, it is normally installed on a container radially further out on the curved shoulder of the container than are drain nipples of the prior art. Containers are stronger at their rounded shoulders. Further, the containers on which the filter-valve assembly is installed should not be otherwise vented. 
     It will be understood by those of ordinary skill in the art that the filter-valve assembly of this invention has many advantages. The mounting-valve poppet of the mounting-valve unit prevents the flow of gases, as well as liquids, from the tank  18 ′ through the exit bore  56  if there is no filter-cartridge assembly  22  attached to the mounting-valve-unit housing. 
     Equally as important, a high side of the mounting-valve-unit housing  40  extending a substantial distance along the first-stage filter housing  67  (at least ⅕ of the way) protects the first-stage filter  62  from breaking if the collection container  10 ′ falls from a table, for example. But, on the other hand, the side of the mounting-valve-unit  40  is not so high (not more than ½ of the way) that it prevents a user from looking into the translucent first-stage filter housing  40  to see if so much liquid has accumulated therein that the first-stage filter  62  must be replaced. In a preferred embodiment, the mounting-valve-unit housing  40  extends ¼ to ⅓ of the way up the first-stage filter housing  67 . 
     Another important benefit of this invention is that chemicals cannot be drained into the tank  18 ′ unless there is a filter-cartridge assembly  22  attached to the mounting-valve unit  28  because otherwise the mounting-valve poppet  42  is closed and the system is not vented to allow drain flow through the liquid drain nipple  80 . 
     The mounting adaptor  26  with a lower curved, contoured, wall gives the entire filter-valve assembly  20  a stable and sealed seating, while at the same time holding the filter cartridge assembly vertical so as to be aesthetically pleasing. 
     The capsize-activated shut-off disc valve  74  prevents the flow of liquid from the tank  18 ′ should the tank be capsized, even when the filter-cartridge assembly  22  holds the mounting-valve poppet  42  open. 
     The litmus-like material  78  informs users when they must replace the second-stage carbon filter  64   
     Although this invention has been described with reference to a preferred embodiment, it will be understood by those of ordinary skill in the art that many other arrangements are possible within the scope of the invention.