Abstract:
A modulator transportable collective protection system for the decontamination and containment of personnel in a toxic free area. A contamination containment area is provided through which personnel are decontaminated prior to entering the toxic free area. The migration of contaminants is prevented by causing a purge of clean filtered air from the toxic free area to the contamination control area and to the exterior environment. A blower and filter unit provides air to the toxic free area to maintain an over pressure therein, ensuring that all entry to the toxic free area is through a flow of clean air.

Description:
This application is a continuation application of U.S. application Ser. No. 09/437,337 filed Nov. 10, 1999, now U.S. Pat. No. 6,390,110. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates to transportable collective protection systems for decontamination of personnel, and provision of toxic-free areas where injured or infected people can be retained safe from further exposure to nuclear, biological, or chemical hazards (NBC). 
     Such systems are required for both military and civilian applications. They should be readily transportable by land or air, and capable of being quickly set up with a minimum of personnel, either in contaminated or toxic-free locations. Such systems must come complete with their own power supplies, air filter equipment, air conditioning, lighting, plumbing, and be capable of transport to required sites by aircraft or ground vehicles. 
     Performance specifications for such systems require a high standard of materials and design to meet operational requirements in a variety of environments, to safeguard personnel from lethal hazards. This molecular collective protection system must be capable of providing relief from psychological and physiological stresses during sustained operations in a contaminated environment due to the wearing of full Individual Protection Equipment (IPE). The system provides the ability to process contaminated personnel through a Contamination Control Area (CCA) into a Toxic Free Area (TFA), as defined in NATO standards, consistent with service decontamination and contamination control procedures. 
     RELEVANT PRIOR ART 
     U.S. Pat. No. 4,707,953 granted Nov. 24, 1987 to Anderson discloses a light-weight expandable shelter providing protection against chemical, biological agents and nuclear fallout. The shelter has a frame of U-shaped ribs spaced and held parallel by a series of reinforcing members. A cover of flexible material resistant to chemical and biological agents is attached to the frame. An airlock is provided at one end of the shelter, through which access can be gained to the shelter. A blower and filter pressurizes the shelter and airlock. Such a shelter is of limited usefulness for personnel protection. Injured or non-ambulatory personnel cannot be passed through the airlock, and the shelter is not capable of modular expansion to provide different areas for specialized activities. This shelter requires numerous personnel to erect it and considerable time for erection to be completed. Disassembling the shelter would also be slow and labor intensive. 
     Healey, U.S. Pat. No. 4,800,597 issued Jan. 31, 1989 discloses a decontamination shelter consisting of a series of small rooms, each large enough for an individual to disrobe, shower and dress. Each room is separated from the adjacent room by a narrow corridor with a door at one end leading into the corridor from a first room and a door at the opposite end of the corridor giving access to the adjacent room, the corridors being for isolation between rooms. 
     Canadian Patent 2,080,498 issued Mar. 19, 1996, and its U.S. Pat. No. 5,331,991 issued Jul. 24, 1994, disclose a method of establishing and maintaining in sealed tents, an environment which is independent from its surroundings. Filtered air is used to pressurize the tent, and recycled air from the tent is mixed with filtered outside air, when an air pressure is reached, which is higher than a predetermined air pressure. The patent does not disclose entrance and exit details of the tent which impact on the maintenance of pressure within the sealed tent, nor does it address the problems of moving personnel from a contaminated environment to a sealed space, while decontaminating personnel and equipment. 
     SUMMARY OF THE INVENTION 
     The present invention overcomes all of the limitations of the prior art by providing a transportable collective protection system, which is modular and capable of assembly and operation in both contaminated and toxic free environments, and which permits the decontamination of personnel and equipment in a contamination containment area (CCA), prior to entry into the toxic free area (TFA). The migration of contaminants from the CCA to the TFA is prevented by complete decontamination in the CCA, followed by transfer of decontaminated personnel and equipment to the TFA, while maintaining an over-pressure in the TFA causing a purge of clean filtered air from the shelter through the CCA. The over-pressure is maintained by a blower and filter unit which draws in external air, filters it to remove contaminants, and pressurizes the TFA and CCA to a pressure sufficient to inflate the system to a self supporting state and to purge the CCA and any other minor leakage through closures. Separate electrical generating equipment provides power to run the blower and filter unit as well provides power for lighting, heating, air conditioning, and operation of internal equipment, including fresh water and waste water systems. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     In the accompanying drawings, 
     FIG. 1 is a plan view of a collective protection system in accordance with the present invention; 
     FIG. 2 is an exterior view of the system of FIG. 1 with the outer tent partially removed; 
     FIG. 3 is a view of a compound of collective protection units, with the outer tents removed; 
     FIG. 4 is an end view of the outer decontamination area of the collective protection system of the invention; 
     FIG. 5 is a plan view of an alternative arrangement of units showing the personnel movement and counter air flow of the invention; 
     FIG. 6 is a plan view of a toxic control and decontamination unit; 
     FIG. 7 is a plan view of a three section 120 man sleeping and eating facility, which can also be used for a four bed operating room, fifteen bed field hospital; 
     FIG. 8 illustrates the alternative use of the collective protection system in a contaminated area and at the edge of a contaminated area where the system provides an entry/exit to the area; 
     FIG. 10 is a plan view of a contamination control area as part of a collective protection system; 
     FIG. 11 is a plan view of the toxic free area TFA, with auxiliary equipment attached, and 
     FIG. 12 is a plan and elevation view of a personnel flow-through shower in a collective protection system. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to FIG. 1, there is shown in plan view a collective protection system  10  consisting of an entrance  11  into a Contamination Control Area (CCA)  12 , coupled through an air lock  13  to a Toxic Free Area  14 , connected to a Generator  15  and NBC filter and fan unit  16 . A second exit  17  is connected to the CCA  12 . The CCA  12 , TFA  14 , entrance  11 , airlock  13 , and exit  17  which form the inner liner of the system are constructed of an air tight plastic with welded seams and are connected together by zippers joining the components. Preferably, the plastic material of the liner is a chemical resistant composite consisting of a High Density Polyethylene (HDPE) woven material, laminated to a barrier film and coated on both sides with low density polyethylene LDPE films. UV inhibitors and flame resistant additives are added to provide for long term outdoor exposure and a degree of fire resistance. The outer shell of the system  10  (not shown on FIG. 1) is mounted on a standard modular tent frame consisting of A frames and purlins of aluminum, the outer shell being a similar HDPE weave, laminated to a barrier film and coated on both sides with LDPE. The exterior surface is treated with a coating dyed Desert Tan or Olive Drab, as required. By increasing the weight of the outer cover it is possible to provide protection from shrapnel. Examples of inner liner and outer shell materials are shown in tables 1, 2 and 3. 
     
       
         
               
             
               
               
               
               
               
             
               
               
               
               
               
             
           
               
                 TABLE 1 
               
             
             
               
                   
               
               
                 Chemical Resistant Inner Liner 
               
               
                 High density polyethylene weave laminated to a barrier film 
               
               
                 and coated on both sides with low density polyethylene 
               
             
          
           
               
                 Property 
                 Unit 
                   
                 Values 
                 Test Method 
               
               
                   
               
             
          
           
               
                 Construction 
                 Tapes/in 
                 Warp 
                 9.1 
                 ASTM D3775 
               
               
                   
                 Tapes/in 
                 Weft 
                 8.9 
               
               
                 Unit Weight 
                 oz/yrd2 
                   
                 6.6 
                 ASTM D3775 
               
               
                 Tensile Grab 
                 lbf 
                 Warp 
                 178 
                 ASTM D1682-64 
               
               
                 Strength 
                 lbf 
                 Weft 
                 202 
               
               
                 Tear Strength 
                 lbf 
                 Warp 
                 27 
                 ASTM D2261-71 
               
               
                 *(tongue) 
                 lbf 
                 Weft 
                 34 
                 ASTM D2261-71 
               
               
                 Coating Thickness 
                 mil 
                 Natural 
                 1.5 
                 ASTM D1777 MOD 
               
               
                   
                 mil 
                 Natural 
                 1.5 
               
               
                 Flammability 
                   
                   
                 Pass 
                 NFPA 701 L 
               
               
                   
               
               
                 Barrier film is laminated to HDPE woven scrum and then coated on both sides with DDPE, UV inhibitors and flame resistant additives are added to provide for long term outdoor exposure and a degree of fire resistance.  
               
               
                 These values are typical and are not intended as limiting specifications.  
               
             
          
         
       
     
     
       
         
               
             
               
               
               
               
               
             
               
               
               
               
               
             
           
               
                 TABLE 2 
               
             
             
               
                   
               
               
                 Chemical Resistant Outer Cover (Light Weight) 
               
               
                 High density polyethylene weave laminated to a barrier film and 
               
               
                 coated on both sides with low density polyethylene 
               
             
          
           
               
                 Property 
                 Unit 
                   
                 Values 
                 Test Method 
               
               
                   
               
             
          
           
               
                 Construction 
                 Tapes/in 
                 Warp 
                 10.2 
                 ASTM D3775 
               
               
                   
                 Tapes/in 
                 Weft 
                 10.4 
               
               
                 Unit Weight 
                 oz/yrd2 
                   
                 7.3 
                 ASTM D3775 
               
               
                 Tensile Grab 
                 lbf 
                 Warp 
                 225 
                 ASTM D1682-64 
               
               
                 Strength 
                 lbf 
                 Weft 
                 208 
               
               
                 Tear Strength 
                 lbf 
                 Warp 
                 40 
                 ASTM D2261-71 
               
               
                 *(tongue) 
                 lbf 
                 Weft 
                 62 
                 ASTM D2261-71 
               
               
                 Coating 
                 mil 
                 Desert Tan 
                 1.6 
                 ASTM D1777 MOD 
               
               
                 Thickness 
                   
                 Olive Drab 
               
               
                   
                 Mil 
                 Desert Tan 
                 1.6 
               
               
                   
                   
                 Olive Drab 
               
               
                 Flammability 
                   
                   
                   
                 NFPA 701 L 
               
               
                   
               
               
                 Barrier film is laminated to HDPE woven scrum and then coated on both sides with DDPE, UV inhibitors and flame resistant additives are added to provide for long term outdoor exposure and a degree of fire resistance.  
               
               
                 These values are typical and are not intended as limiting specifications.  
               
             
          
         
       
     
     
       
         
               
             
               
               
               
               
               
             
               
               
               
               
               
             
           
               
                 TABLE 3 
               
             
             
               
                   
               
               
                 Chemical Resistant Outer Cover (Heavy Weight) 
               
               
                 High density polyethylene weave laminated to a barrier film and 
               
               
                 coated on both sides with low density polyethylene 
               
             
          
           
               
                 Property 
                 Unit 
                   
                 Values 
                 Test Method 
               
               
                   
               
             
          
           
               
                 Construction 
                 Tapes/in 
                 Warp 
                 16 
                 ASTM D3775 
               
               
                   
                 Tapes/in 
                 Weft 
                 16 
               
               
                 Unit Weight 
                 oz/yrd2 
                   
                 10 
                 ASTM D3775 
               
               
                 Tensile Grab 
                 lbf 
                 Warp 
                 371 
                 ASTM D1682-64 
               
               
                 Strength 
                 lbf 
                 Weft 
                 360 
               
               
                 Tear Strength 
                 lbf 
                 Warp 
                 116 
                 ASTM D2261-71 
               
               
                 *(tongue) 
                 lbf 
                 Weft 
                 118 
                 ASTM D2261-71 
               
               
                 Coating 
                 mil 
                 Desert Tan 
                 1.6 
                 ASTM D1777 MOD 
               
               
                 Thickness 
                   
                 Olive Drab 
               
               
                   
                 Mil 
                 Desert Tan 
                 1.6 
               
               
                   
                   
                 Olive Drab 
               
               
                 Flammability 
                   
                   
                   
                 NFPA 701 L 
               
               
                   
               
               
                 *Includes force to shift tapes - Tear may be crosswise to direction of force.  
               
               
                 Barrier film is laminated to HDPE woven scrum and then coated on both sides with DDPE, UV inhibitors and flame resistant additives are added to provide for long term outdoor exposure and a degree of fire resistance.  
               
               
                 These values are typical and are not intended as limiting specifications.  
               
             
          
         
       
     
     FIG. 2 illustrates the standard modular tent frame  20 , with the inner liner  21  inside the frame  20 , and an outer shell  22  draped over the frame  20 , and held in place by conventional means, including securing the outer shell to the ground around the perimeter of the system. The outer tent chemical cover may optionally be colored with a suitable camouflage pattern, if required by the location and use of the system. 
     The illustration of FIG. 3 clearly shows a plurality of interconnected systems with the outer shells removed. The standard modular tent frames clearly may be seen, together with the inner liners positioned within the frames, and with looped tabs extending from the inner liners to the frames. 
     FIG. 4 is a view from the left end of FIG. 1 showing the entrance  11  and the CCA  12 . The outer decontamination area is external to the entrance, but beneath the outer shell. Decontaminant containing pans are provided at this location for removing toxic material from personnel and equipment prior entry into the entrance  11  to the CCA  12 . The preferred decontaminant used is RSDL, which can be applied to individual protective equipment (IPE), weapons, other equipment, human skin and wounds, without damage, and with instant neutralization of toxic NBC material. 
     All components of the system may be mounted on a trailer for ground transportation, or a pallet for air transport, which facilitates the rapid movement of systems to locations requiring the systems. 
     It will be appreciated by those familiar with the difficulty of providing a toxic free area (TFA), that each module of the system is a sealed unit, having a floor, walls and ceiling welded and/or sewn together forming a sealed volume, which may be connected to other modules by zipper connections, having minimal leakage. The important feature is that there is a flow of air through the system toward the source of contamination, and that decontamination occurs principally at the downstream end of the air flow. There is an over pressure maintained in the TFA which ensures that all air flow is toward the source of contamination, as doors are opened and closed, and that nothing is permitted into the TFA that has not been through the CCA. It will be noticed that the zippers  31  of FIG. 4 which comprise the opening into the exit  11 , are configured to minimize the escape of air during entry into the CCA  12 . By opening the zippers in the doors a limited amount, the flow of air through the CCA  12  can be regulated. Vents are also included in the end walls of the CCA  12  which may be adjusted to ensure adequate flow of air through the CCA  12 , and to maintain an over pressure in the TFA. 
     A typical system of the invention includes on a pellet: 
     one 10 KV 60 Hz generator fixed to the pallet; 
     NBC filter system providing a minimum of 300 cfm. And capable of filtering and maintaining an over pressure in three inter-connected units at one time; 
     an independent air conditioning/heating unit for independent climate control up to three complete connected liner units, each measuring 14 ft.×24 ft. by 6 ft. minimum clearance. 
     Each liner unit comes with sub-floor, inner floor, emergency repair kit, two replaceable doors all inner support apparatus and an extendible storage or toilet facility. All units come complete with basic electrical hook up system of 110/220 v plug-ins, basic lighting, remote controls and gauges for generator, filter, and AC/heater units. 
     FIG. 5 is a plan view of a specialized application for biological/radiological showers, illustrating the counter flow of personnel and air flow to maintain the TFA free of contaminants. It will be appreciated that the view of FIG. 5 omits the outer shell for clarity, it being understood that all systems will include such a shell mounted on a standard modular tent frame. 
     FIG. 6 is a plan view of an alternate arrangement of units, with air flow from right to left in the view and personnel flow from left to right, counter the air flow. 
     FIG. 7 is an alternative arrangement which can provide sleeping and eating facilities for 120 men, or can be used for a four bed operating room/15 bed ward field hospital. The shaded areas  40  represent the typical form of barrier which could be erected around such a facility for security, and to prevent direct penetrating fire of hostile forces from striking the system. As illustrated the outer shell of the system extends over all units of the system, and the TFA at the right hand end of the system is composed of three units joined together, and supplied with water and sanitary facilities from water bladder  41  connected to a water heater  42  on the trailer, connected to shower and toilet unit  43 . 
     FIG. 8 illustrates a complex of systems, each provided with its own power and air flow equipment, and providing a CCA and TFA for each system, which is contained within an outer shell independent from each other. Such an arrangement is desirable for certain military applications. 
     FIG. 9 illustrates two possible environmental locations for systems. The upper view shows a typical setup in a toxic environment, whereas the lower view illustrates a setup at the boundary of a toxic area, where a dirty/clean line has been established and personnel are passed through the system between the contaminated area and the clean or non-contaminated area. 
     FIG. 10 is a detailed view of the CCA of a system, where a liquid/vapor hazard is provided under the cover of the outer shell, a liquid hazard decontamination area inside the CCA, connected to a vapor hazard decontamination area also within the CCA, but isolated from the liquid hazard area, and connected by an airlock to the TFA. 
     FIG. 11 is a detail of the facilities coupled to the TFA as illustrated in FIG.  7 . 
     FIG. 12 is a detail of a system in which the CCA consists of a plurality of showers, and personnel flow is left to right and air flow is right to left. Dependent upon the nature of the hazard, such a CCA may be adequate to deal with detoxifying personnel, on their way to the toxic free area (TFA). 
     Many other configurations of the system are possible, the principle to be observed is that the air flow is counter to the personnel flow and that there be a CCA prior to a TFA for personnel movement. Preferably the inner liner is erected by inflation inside a standard modular tent frame and an outer shell is mounted over the frame. Preferably the system is transportable either on a pallet or a trailer with all electrical and air flow systems included with the system.