System and method for detecting hazardous materials using agitation

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation-in-part of application Ser. No. 10/277,069 filed Oct. 21, 2002 for System and Method For Detecting Hazardous Materials Inside Containers, which claims the benefit of provisional application Serial No. 60/330,673 filed Oct. 26, 2001 and a continuation-in-part of application Ser. No. 10/201,169 filed Jul. 22, 2002 for Closed Loop System For Air Sampling Of Contained Mail Products, which claims the benefit of provisional application Serial No. 60/344,848 filed Dec. 31, 2001, and the entire contents of all such applications are incorporated herein by reference.

BACKGROUND OF THE INVENTION

The present invention relates to a system and method for detecting hazardous materials inside articles and, more particularly, to a system and method for detecting hazardous materials inside mail.

All economies depend upon the physical shipment of materials for their functioning including the shipment of mail, merchandise, raw materials, and other goods.

In some circumstances, it is desirable to subject the goods to some type of inspection to determine the presence of hazardous or impermissible materials, including biological and chemical materials. In general, sophisticated sensing systems are known for the detection of hazardous biological and chemical materials For example, such systems can include conventional laboratory facilities as well as mobile or semi-mobile units that can automatically or semi-automatically detect the presence of the undesired substance or substances. One such vehicle-mobile system is the Joint Biological Point Detection System (JBPDS) developed for the United States military and designed to detect the presence of a number of biological pathogens. Others include sensor or detectors for hazardous chemicals, explosives, illicit drugs, radioactive particles, and other hazardous materials. These sensors can be used single, or in combinations, to detect as many types of hazardous particles or vapors as required.

Currently when there is suspicious mail, it is all bulk irradiated, as was done during the recent anthrax problem in the U.S., thereby delaying some mail for months and damaging or destroying some of the mail due to problems caused by the irradiation. For example, some of this irradiated mail becomes brittle and pieces break off.

U.S. Published Application No. US 2002/0126008 published Sep. 12, 2002 and filed Oct. 31, 2001 discloses use of sensors at various locations within a typical mail processing system to sense the presence of a harmful agent. This system is completely open to the ambient atmosphere. (The present application is based upon a provisional patent application filed Oct. 26, 2001.)

U.S. Published Application No. US 2002/0124664 published Sep. 12, 2002 and filed Feb. 1, 2002 discloses use of a mail sampling system used in a room separate from the remainder of a post office facility and in which there is an air intake fan and all outgoing air is filtered before release. Most often openings are formed in the parcels and mail for the sampling. The sampling system is said to determine whether mail is contaminated with a chemical or biological agent. (The present application is based upon a provisional patent application filed Oct. 26, 2001.)

U.S. Pat. Nos. 5,942,699 and 6,324,927 disclose a manner of collective sampling of cargo items for contaminants such as chemical residues. The cargo items are placed into a special airtight chamber and physically agitated, such as by vibration, to release particulates and vapors from the items, and bursts of high pressure air is sent into the chamber. Heated air may also be used.

U.S. Pat. No. 3,915,339 discloses use of pressurized air into a container to loosen and cause free flow of material therein move.

U.S. Pat. No. 3,998,101 discloses a method and apparatus for sampling the atmosphere in non-hermetically-sealed containers by enclosing baggage in a chamber and varying the air pressure cyclically to mix a portion of the air in the baggage with the air in the chamber and a vapor detector is used to detect the presence of explosives or drugs in the baggage.

U.S. Pat. No. 4,580,440 discloses a method of detecting a contraband substance in freight cargo in which the container is agitated to disturb particulates therein and samples are taken of the air containing such particulates. The collected particulates are heated to drive off vapors indicative of the contraband substance and the vapors are analyzed in a mass analyzer.

U.S. Pat. No. 4,718,268 discloses a method and apparatus for detecting a contraband substance in freight cargo similar to that of U.S. Pat. No. 4,580,440 mentioned above.

U.S. Pat. No. 5,841,038 discloses a remote sampling device for possibly hazardous content of a container. A hollow needle punctures the container and is used to withdraw the contents or to introduce another substance. An inert gas can be introduced into the area where the needle punctures the container.

U.S. Pat. No. 5,859,362 discloses a trace vapor detection method and device of sampling a volume of air suspected of containing drug vapors, removing particulate matter and binding vapors of the drug for further analysis. The device has sampling, filtration and vacuum port components.

U.S. Pat. No. 6,295,860 for explosive detection system and sample collecting device in which luggage enters the device and leaves the device after inspection in which a vapor leaking from the luggage is sampled by a sampling probe, negative corona discharge is used to ionize the vapor, and a mass spectrometer is used to detect the ionized vapor to determine whether or not an explosive is present.

Patent Abstracts of Japan Pub. No. 02159554 A published Dec. 12, 1988, Application No. 63313358 discloses a monitoring method of a pathogen or allergen in which a biosensor is provided near a suction port for air conditioning provided for each room of wall surface which tends to gather mold.

WO 91/09307 published Jun. 27, 1991, for Explosive Detection Screening System detects vapor or particulate emissions from explosives and other controlled substances and reports their presence and may also report the concentration. There is a sampling chamber for collection of vapors or other controlled substances and a concentration and analyzing system, and a control and data processing system for the control of the overall system. There are a number of U.S. patents in this series, including the following: U.S. Pat. Nos. 4,987,767; 5,109,691; 5,345,809; 5,465,607; and 5,585,575.

SUMMARY OF THE INVENTION

The US Postal Service has no reliable manner of determining if anthrax, or other hazardous materials, are contaminating items of mail. It is desirable to do this before mail enters sorting and distribution centers. The present invention provides a system and method for detecting hazardous materials in or on mail.

The present invention is a system and method for detecting contaminants in and around objects, including mail pieces and parcels, and may include neutralizing the environment containing the contaminants or the contaminants themselves. The system of the present invention may include, but is not limited to, a housing such as a cabinet, a perforated container or surface, an air duct subsystem, a power subsystem, a sensor subsystem, an indicator subsystem, and a controller. Optionally, the system of the present invention can include a blower subsystem and a neutralization subsystem.

The housing creates an enclosure and forms an airflow barrier between the enclosure and the outside ambient air. The housing has a housing opening for inserting and removing the object(s). When there is a container, it forms a cavity for holding the object(s). The container has a shell with a plurality of perforations, or may be made of wire in which case there are already openings, and it is rotatably mounted within the housing. The container has at least one container opening for inserting and removing the object(s). When there is a surface with openings, the objects are supported by the surface. The power subsystem, operably connected to the container, rotates the container, or shakes or agitates or vibrates the surface.

The sensor subsystem tests an air stream for contaminants. The indicator subsystem is operably connected to the sensor subsystem and provides a signal when at least one contaminant is detected.

The air duct subsystem is capable of ducting the air stream to an appropriate place within the system. In one embodiment, the air duct subsystem can duct the air stream into a perforated pipe that is mounted within the container or adjacent to the perforated surface. The perforated pipe allows the air stream to enter in one case the cavity and in the other case perforations in the surface and the perforations allow the air stream to flow through and about the articles. The air duct subsystem can receive the air stream from the enclosure and/or adjacent the perforated surface and can duct it past the sensor subsystem, optionally forced by the blower subsystem.

Current devices that could detect and safeguard against biological agents can present further problems such as introducing additional contaminants into the air sample that may cause false alarms or shorten the life span of contaminant detection devices. Some current devices are deficient in that they allow the migration of deadly contaminants to the outside environment, or they require the use of costly high efficiency particle air filters (HEPA) filters to process air before release to the outside environment.

In one type of arrangement, the unit is self-contained and is a closed loop system in which the air is recirculated and not allowed to enter the ambient atmosphere. In such a system a HEPA filter is not needed.

The air duct subsystem is capable of ducting the air stream in a closed loop throughout the system. The air duct subsystem can duct the air stream into a perforated pipe that is mounted within the container. The perforated pipe allows the air stream to enter the cavity, and the perforation(s) in the cavity allows the air stream to enter the enclosure. The air duct subsystem can receive the air stream from the enclosure and can duct it past the sensor subsystem and back through the housing into the container, optionally forced by the blower subsystem.

In another type of arrangement, the air is filtered and then released to the atmosphere.

In another embodiment, there are air inlet and outlet openings in the container which permit air to enter and to leave.

The controller sequences operations among the sensor subsystem and the power subsystem so that particles that can be emitted while the object(s) are being tumbled within the cavity when the container is rotating. The particles can pass through the perforation(s) in the container from the cavity to the housing and then are entrained with the air stream into the air duct subsystem. The air stream and particles exit the housing and are ducted past the sensor subsystem which sends a signal to the indicator subsystem if contaminant(s) is detected in the particles.

Optionally, the blower subsystem can force the air stream through the air duct subsystem. If a blower subsystem is used to force the air stream, the controller can sequence activities among the blower subsystem, the sensor subsystem, and the power subsystem. Also optionally, when contaminant(s) is detected, a neutralization mechanism can inject a conventional contaminant neutralizer such as chlorine-calcium, formalin, or lye solutions into the air stream in the air duct subsystem. If a neutralization mechanism is used, the controller can sequence activities among the neutralization mechanism, the sensor subsystem, and the power subsystem, and optionally the blower subsystem.

The method of the present invention includes the steps of loading a perforated container or surface with at least one object, enclosing the perforated container or surface within a housing, and sealing the housing. In this method, the step of sealing forms an ambient air barrier which prevents air and particles emitted from the perforated container or surface into the housing from entering the ambient air outside the housing. The method of the present invention further includes the step of rotating the perforated container or vibrating the perforated surface. Rotation of the perforated container that contains objects can serve to release particles that are on and in the objects within the perforated container into an air stream that entrains emitted particles. It also includes, in another embodiment, the step of vibrating the perforated surface to release hazardous particles that are on and in the objects within the housing. The method further includes the step of sampling the air stream that enters the housing through the perforations in the container or surface. The method includes the steps of testing for at least one contaminant and providing an indicator if at least one contaminant is detected. The method can optionally include the steps of forcing air into the rotating perforated container, which in turn is forced through the perforations into the housing or forcing air in the vicinity of the perforated vibrating surface, and introducing a neutralizing agent into the air stream if the air stream contains at least one contaminant.

The container is not filled to capacity so as to allow room for the mail to “waterfall” during rotation. The speed may be adjustable so that the mail can tumble and collide. If desired, this can be made variable using software based upon the load that is sensed by sensors which are a part of the system using such software.

In one type of system air flow is established within a container to sweep hazardous particles that are entrained in the interior air and dislodge particles from surfaces therein and sweep the particles into a sensor unit for analysis. A container may be provided with at least one wall surface, which, in one embodiment, is the floor surface, as an air distribution plenum with air-flow holes or openings therein to allow the establishment of an air flow path within the container.

During the time that the air flow pattern is established, a hazardous-materials detection sensor or sensor system is located at or otherwise introduced into the air flow pattern, preferably at or downstream of the air exit port, for a sufficient period of time to sample the flow for a plurality of undesired or hazardous materials.

The distribution plate or surface defines an air distribution plenum therebeneath and includes a plurality of holes distributed across its surface. The air flow pattern can be established by an air-moving fan located within the container or by an auxiliary piece of equipment that connects to the container through an air inlet port and air outlet port to establish a desired air recirculation flow for some period of time. Once the flow has been established, a sensor or sensors are located within the exhaust flow for some period of time sufficient to effect the detection of any undesired or hazardous materials.

The present invention advantageously provides a system and method for quickly and efficiently detecting hazardous materials inside housings while the shipped materials are contained and prior to the unloading of the housing and possible dissemination/distribution of any hazardous materials.

Other features and advantages will be apparent from the following detailed description of preferred embodiments taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

<figref idref="DRAWINGS">FIG. 1</figref> is a schematic block diagram of the components of the system of the present invention.

<figref idref="DRAWINGS">FIGS. 2A and 2B</figref> are flowcharts of the method of an embodiment of the present invention.

<figref idref="DRAWINGS">FIG. 3</figref> is an isometric view of an embodiment of the system of the present invention.

<figref idref="DRAWINGS">FIG. 4</figref> is an isometric view of a front view of an embodiment of the system of the present invention.

<figref idref="DRAWINGS">FIG. 5</figref> is an isometric view of a rear view of an embodiment of the system of the present invention.

<figref idref="DRAWINGS">FIG. 6</figref> is an isometric view of a front view of the open housing and container of another embodiment of the housing stand of the present invention.

<figref idref="DRAWINGS">FIG. 7</figref> is an isometric partial view, taken from the rear, of the interface board and perforated container within the housing of an embodiment of the present invention.

<figref idref="DRAWINGS">FIG. 8</figref> is an isometric partial view, taken from the front, of the perforated container and interface board of an embodiment of the present invention.

<figref idref="DRAWINGS">FIG. 9</figref> is an isometric view of another embodiment of the present invention in which the sensors and indicator are directly sensing the air stream in the housing.

<figref idref="DRAWINGS">FIG. 10</figref> is an isometric view of a further embodiment of the present invention in which the blower, sensors, and indicator, are blowing an air stream directly into the housing and directly sensing the air stream in the housing respectively.

<figref idref="DRAWINGS">FIG. 11</figref> is a schematic isometric view of a system for detecting hazardous material which is located upstream from the usual mail sorting/transporting system, and shows a ganged system.

<figref idref="DRAWINGS">FIG. 12</figref> is a schematic isometric view of a rotating cage embodiment.

<figref idref="DRAWINGS">FIG. 13</figref> is a schematic isometric view of a vibrating surface embodiment.

<figref idref="DRAWINGS">FIG. 14</figref> is a schematic isometric view similar to that of <figref idref="DRAWINGS">FIG. 13</figref>, but where the surface is irregular.

<figref idref="DRAWINGS">FIG. 15</figref> is a diagrammatic view of another embodiment of the present invention.

<figref idref="DRAWINGS">FIG. 16</figref> is a schematic isometric view of a module being loaded with mail by a worker.

<figref idref="DRAWINGS">FIG. 17</figref> is a schematic isometric view of a hex basket type rotating cage.

<figref idref="DRAWINGS">FIG. 18</figref> is a housing for a hex basket rotating cage.

<figref idref="DRAWINGS">FIG. 19</figref> is a view of a portion of the front of a hex basket rotating cage.

<figref idref="DRAWINGS">FIG. 20</figref> is a tote basket rotating cage.

<figref idref="DRAWINGS">FIG. 21</figref> is a housing for a tote basket rotating cage.

DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION

Previous attempts to detect hazardous materials in mail integrated the liberation device with the detection device. The present invention separates the two processes and incorporates multiple liberation modules to produce a flow of “free from contaminant” mail available for sorting. This logistic method decreases cost of detection through multi-module application of the detection instrumentation and also allows technology refreshing of instrumentation while maintaining the liberation hardware. Implementing this disclosure eliminates decontamination of sorting machinery, equipment or process, in that, contaminated mail never reaches those devices.

<figref idref="DRAWINGS">FIG. 11</figref> shows such a system schematically. It includes a bank <b>118</b> of modules for detecting hazardous material in mail. Each component <b>120</b> of the module provides a separate housing for processing batches of mail to assure they are free of hazardous material before they are released into the sorting system. The module <b>118</b> has an exit chamber <b>122</b> into which mail is delivered when it is determined that hazardous materials are not present. The arrow <b>124</b> indicates a means of delivering the mail from the module to the sorting apparatus.

There is also a bank of detection instrumentation <b>126</b>, which may, if desired, also include apparatus for neutralizing the hazardous material. A schematic showing of a bus of electric or signal wiring and air ducting <b>128</b> is connected between the module <b>118</b> and the instrumentation/neutralization unit <b>126</b>.

System <b>10</b> of the present invention, shown diagrammatically in <figref idref="DRAWINGS">FIG. 1</figref>, includes, but is not limited to, a sealed or sealable housing <b>107</b> forming an enclosure, the enclosure containing a perforated container <b>109</b> forming a chamber or cavity, a sensor subsystem <b>105</b>, and an indicator subsystem <b>113</b>. Optionally, system <b>10</b> can include a blower subsystem <b>101</b>. Components <b>101</b>, <b>105</b>, and <b>107</b> are in airflow communication through air duct subsystem <b>103</b>. In addition, a power subsystem <b>111</b>, an optional neutralization subsystem <b>115</b>, and a controller <b>117</b> complete system <b>10</b>.

In operation, perforated container <b>109</b> is rotated by power subsystem <b>111</b> while optional blower subsystem <b>101</b> forces an air stream through air duct subsystem <b>103</b>. When perforated container <b>109</b> is loaded with objects, such as mail pieces and/or parcels, and rotated, any loose particles that are on or in the objects can be released and entrained in the air stream. These particles can eventually be forced into the enclosure formed by the sealed housing <b>107</b> through the perforations in perforated container <b>109</b> by the pressure of air flowing into the perforated container <b>109</b> and by the centrifugal force generated within the container. The particles can then be entrained into the air stream that is flowing into sealed housing <b>107</b> from the perforations in perforated container <b>109</b>. This air stream is ducted by the air duct subsystem <b>103</b> past sensor subsystem <b>105</b> where it is tested by conventional sensor equipment, such as, for a nonlimiting example, the BIONI or Biological Aerosol Real Time Sensors manufactured by Pacific Scientific Instruments and the Biological Aerosol Warning Systems I, developed by the assignee of this application, or any cost-effective, real-time sensor for airborne biological particles or other contaminants. If contaminants are detected, indicator subsystem <b>113</b> provides an indication of the presence of contaminants. Optionally, neutralization subsystem <b>115</b> can operate cooperatively with the sensor subsystem <b>105</b> to neutralize contaminants in the air stream and also to neutralize contaminants in or on the objects bearing the contaminants. Controller <b>117</b> can sequence operations among the various subsystems, for example, activation and deactivation of the blower subsystem <b>101</b> and the power subsystem <b>111</b>.

Referring now to <figref idref="DRAWINGS">FIG. 2A</figref>, one of the methods of the present invention includes the step of loading a perforated container with objects and closing the container (method step <b>201</b>). This method further includes the steps of enclosing the perforated container within a housing and sealing the housing to prevent gas exchange between the air inside the housing and the air outside the housing (method step <b>203</b>). This method next includes the step of rotating the perforated container and the objects within the perforated container so that any particles that might on or in the objects are shaken loose by the rotation and emitted into an air stream surrounding the objects within the container (method step <b>205</b>). The method further includes the steps of sampling the air stream by the sensors for the presence of contaminants (method step <b>207</b>), the decision step of determining whether the air stream contains at least one contaminant (decision step <b>109</b>), and setting an indicator if at least one contaminant is detected (method step <b>211</b>).

Referring now to <figref idref="DRAWINGS">FIG. 2B</figref> optional steps that can be taken if the air stream contains contaminant(s) include introducing a conventional neutralizing agent into the air stream if at least one active contaminant is detected (method step <b>213</b>) to neutralize the air stream. The neutralizing agent is also used on the objects from which the contaminants were detected. The method includes the further step of stopping the system and taking actions to make the workplace safe and to isolate contaminated objects (method step <b>215</b>). If the air stream is found to be free of contaminants, the method of the present invention includes the steps of stopping and unloading the perforated container (method step <b>217</b>).

Referring now to <figref idref="DRAWINGS">FIG. 3</figref>, system <b>10</b> of this embodiment of the present invention includes housing <b>13</b>, mounted on housing stand <b>31</b>, and having a housing lid <b>21</b>, capable of being opened. In this embodiment, the housing can be, for a nonlimiting example, predominately 16-18 gauge stainless steel or any material to allow for corrosion resistance and internal sanitization if necessary. An external framework of powder-coated steel or any other type of material can be used for supporting the housing. The housing can be any size, and could be specially constructed to accommodate certain sizes of objects or areas of application. For example, if the system is to be used primarily in a mailroom, that application could require a relatively large housing to accommodate packages that might be entering the mailroom. On the other hand, if the system were primarily for home use, the housing could be quite small, if desired, to accommodate analysis of flat letters only, for example.

The housing lid <b>21</b> is preferably, although not necessarily, a lift-open glass door operably connected to the housing <b>13</b> by lid hinges <b>48</b> (shown in FIG. <b>6</b>). System <b>10</b> also includes conventional sensors <b>17</b> which are, in this embodiment, a particle sensor and a biological agents sensor, the complementary action of which enhances contaminant detection possibilities. The particle sensing system, illustratively the BAWS I system, is specially suited to detect particles in the 2-10 micron range favored for aerosol dispersion of biologic agents. The biological agents sensor, illustratively the BAWS III sensor, utilizes ultra-violet laser fluorescence technology to analyze captured particles for the presence of biological agents. In this embodiment, the two sensors can be coupled together by an RS-232 communications line, or any other appropriate electronic communications mechanism. The particle sensor can communicate with a controller <b>11</b> through an RF link to the RF radio network or any other suitable means of wired or wireless electronic communications. Any sensors, including but not limited to chemical, biological, and particle, can be used in the system of the present invention.

Controller <b>11</b>, which can be a personal computer, a programmable logic controller, or other such device, is operably connected to interface panel <b>44</b> (shown in FIG. <b>5</b>). In this embodiment, controller <b>11</b> is a personal computer with a Universal Interface Unit for connecting external sensors and an RF network radio. The personal computer of this embodiment operates under any operating system that supports the appropriate hardware and software to interface with and control the various components of the system. Application software to control system <b>10</b> is standard BAWS sensor software with upgrades as follows: (1) a new communications message format is added to accommodate information from the sensors of system <b>10</b>, and (2) the software is modified for non-military use. Any application software appropriate for the sensors selected for the system can be used.

System <b>10</b> can also contain a visual indicator <b>15</b>, which is an embodiment of the indicator subsystem <b>113</b>, that can be color-coded to indicate contamination states. System <b>10</b> also includes a rear housing door <b>19</b> through which the operator can access the interface panel <b>44</b>, but which does not allow gas exchange with the air-sealed environment of the housing <b>13</b>. System <b>10</b> also can optionally include discharge handle <b>25</b> and discharge receptacle <b>27</b>. (When used in a mail system, the receptacle can be any of the receptacle types presently used in mail systems.) Discharge handle <b>25</b> can be pressured manually to release objects from the container <b>55</b> (shown in <figref idref="DRAWINGS">FIG. 6</figref>) and housing <b>13</b> into discharge container <b>27</b>, which can be any container suitable for the weight and size of the objects being tumbled in container <b>55</b>. The handle <b>25</b> and housing <b>13</b> are operably connected by an interlocking conventional mechanical linkage having a conventional camming feature that reliably seals the discharge hatch lid <b>35</b> (FIG. <b>4</b>). The conventional interlocking mechanism insures that the housing <b>13</b> is incapable of being opened during use. It is envisioned that this could be used manually or could be operated by the control system and could a pneumatically- or electrically- or hydraulically-controlled, so manual intervention is required. In this embodiment, an optional loading ramp <b>29</b> is shown, having ramp rails <b>23</b> and leading to the housing <b>13</b>. The loading ramp <b>29</b> can aid in transporting objects to and loading objects into housing <b>13</b>.

Referring primarily now to <figref idref="DRAWINGS">FIG. 4</figref>, the front of the housing <b>13</b>, housing stand <b>31</b> and controller <b>11</b> is shown. In this embodiment, controller stand <b>60</b>, mounted on controller shelf support <b>59</b>, is operably connected to housing <b>13</b> and housing stand <b>31</b>. Controller <b>11</b> can be located any distance from housing <b>13</b>, but must have electronic (wired or wireless) connection with interface board <b>44</b> (shown in FIG. <b>5</b>). Also shown is control panel <b>37</b> which, in this embodiment, is a panel with start, stop, load/unload, and emergency stop buttons. Also shown are housing lid latches <b>18</b> that insure that the housing is sealed against gas exchange with the ambient workspace. Also shown are housing recess <b>33</b> and housing discharge lid <b>35</b>. Housing recess <b>33</b> is formed to allow free rotation of container <b>55</b> (see FIG. <b>6</b>). Housing discharge lid <b>35</b> is operably connected to handle <b>25</b> such that when handle <b>25</b> is depressed, after housing discharge lid <b>35</b> is opened and the removable lid (not shown) is removed from container <b>55</b>, container <b>55</b> rotates into discharge position and the objects within container <b>55</b> drop into receptacle <b>27</b>.

<figref idref="DRAWINGS">FIG. 5</figref> shows the rear of housing <b>13</b>, housing stand <b>31</b>, and interface panel <b>44</b>. In this embodiment, interface panel <b>44</b> includes electronics to provide the interface between controller <b>11</b> and operational subsystems of the system of the present invention. For example, controller <b>11</b> allows the operator to stop the rotation of container <b>55</b> through a push-button on control panel <b>37</b>. Interface panel <b>44</b> contains electronics to disable power to motor <b>41</b>, which thus disables rotation of container <b>55</b> (the coupling of motor <b>41</b> to the rotation of container <b>55</b> is shown in FIG. <b>8</b>).

Rear housing wall <b>45</b>, along with interface panel <b>44</b>, complete the rear sealed housing. Interface panel <b>44</b> is covered during operation by rear door <b>19</b> which can be operably connected to the housing <b>13</b> by rear hinges <b>38</b> and latched in place by latch <b>39</b>. Shown also is a pipe of the air duct subsystem <b>43</b>. This part of the piping ducts air from the housing <b>13</b> to the recirculation blower <b>63</b> (shown in FIG. <b>7</b>). This embodiment recirculates the air which leaves the sensors back into the container so that air is not discharged into the atmosphere. However, in other embodiments, the air is not recirculated.

<figref idref="DRAWINGS">FIG. 6</figref> shows another embodiment <b>20</b> of the system of the present invention which includes a housing stand in which the housing <b>13</b> is supported by attached legs <b>51</b> and housing support connectors <b>53</b>. Also shown is the perforated container <b>55</b> and cavity <b>57</b>. <figref idref="DRAWINGS">FIG. 7</figref> provides a rear view of interface panel <b>44</b> and container <b>55</b>, shown with the housing removed. Container <b>55</b>, which can be any shape, is six-sided in this embodiment. Some further detail of this construction is shown in FIG. <b>19</b>. It has a removable lid (not shown, attached conventionally when in place) which, when opened, can admit objects into container <b>55</b> to be tumbled. Once loaded, container <b>55</b>, perforated with one or more perforations <b>67</b>, can be rotated to tumble the objects and agitate them. While the perforations are only shown in the side of rotable container <b>55</b> in this figure, the perforations will generally be located on the periphery of the drum and not always on the sides. The preferred rate of rotation is sufficient to tumble the objects in container <b>55</b>, but not so fast that the objects are pinned to the sides of container <b>55</b>, thus preventing agitation. The air duct subsystem <b>43</b> directs an air stream at the objects within the container by means of a perforated air pipe <b>83</b> (shown in <figref idref="DRAWINGS">FIG. 8</figref>) that also acts as an axle for the rotating container <b>55</b>. Air pipe <b>83</b> is in airflow communication with the air duct subsystem <b>43</b> which junctions with air pipe <b>83</b> at intersection <b>69</b>. Rotating coupling <b>71</b> provides a rotatable connection between the air duct subsystem <b>43</b> and the container <b>55</b> by allowing the air stream to flow through the coupling <b>71</b> while one portion of the coupling <b>71</b> and the container <b>55</b> rotate. Container <b>55</b> is attached to housing <b>13</b> on one side by air duct housing mounting connection <b>77</b>.

Motor sprocket <b>73</b> which drives, for example, a chain, belt, or direct drive, that acts as a container rotation means to rotate the container <b>55</b> is shown. Also shown is blower <b>63</b> which forces the air stream through the air duct subsystem <b>43</b>. It can be seen that air leaving container <b>55</b> at exit port <b>65</b> passes sensor probes <b>61</b> on its way to recirculation blower <b>63</b>. As long as power is supplied to the system, blower <b>63</b> forces the air stream back through interface panel <b>44</b> at air duct housing entry <b>75</b> and into container <b>55</b> at rotating coupling <b>71</b>. If contamination is detected by conventional sensors <b>17</b> through air stream sampling by sensor probes <b>61</b>, a signal is sent to the indicator subsystem and to controller <b>11</b> through interface panel <b>44</b>.

<figref idref="DRAWINGS">FIG. 8</figref> shows the front of container <b>55</b> with the housing removed. In this view, container sprocket <b>87</b> and chain or belt <b>81</b> are shown. Motor <b>41</b> (shown in <figref idref="DRAWINGS">FIG. 7</figref>) drives, and thus provides the rotation to motor sprocket <b>73</b> and thus drives chain <b>81</b> and container sprocket <b>87</b> to rotate container <b>55</b>. Container <b>55</b> is connected to housing <b>13</b> on the motor side by chain or belt drive housing mounting connection <b>79</b>. Air duct junction <b>85</b> is shown by which the air stream is provided by the blower <b>63</b> at air duct housing entry <b>75</b> (shown in FIG. <b>7</b>). When recirculation is used, the requirement for a HEPA filter, as is used in the arrangement shown in <figref idref="DRAWINGS">FIG. 15</figref>, is eliminated.

<figref idref="DRAWINGS">FIG. 9</figref> shows a further embodiment <b>30</b> in which conventional sensors <b>17</b> directly sample air inside the recess <b>33</b> of housing <b>13</b> and provide a first signal to indicator <b>15</b> if at least one contaminant is detected. System <b>30</b> further includes drum or container <b>55</b>, which is six-sided with perforations <b>67</b> in its periphery, the drum <b>55</b> defining cavity <b>57</b>. Cavity <b>57</b> is loaded with objects and then closed as a lid (not shown) is positioned over the opening in container <b>55</b>. After the objects are loaded, housing lid <b>21</b> is shut to prevent gas exchange between the air within housing <b>13</b> and the ambient air. Drum <b>55</b> is rotated by any kind of conventional power supply (not shown), thus tumbling the objects within cavity <b>57</b> and releasing particles associated with the objects into the air in the cavity <b>57</b>. Air and particles mix and exit cavity <b>57</b> through perforations <b>67</b> into the enclosure formed by housing <b>13</b> where the air and particles are tested for contamination by conventional sensors <b>17</b>.

<figref idref="DRAWINGS">FIG. 10</figref>, is a still further embodiment <b>40</b> which is the same as embodiment <b>30</b> except that a conventional blower <b>89</b>, operably connected to housing <b>13</b>, forces air into housing <b>13</b>. The forced air can increase air circulation into container <b>55</b> and conventional sensors <b>17</b>, thus potentially increasing the frequency and reliability of contaminant detection by conventional sensors <b>17</b>.

Whereas some of the previous embodiments have related to a closed loop system, the embodiments to be described below are not usually used in a closed loop, although they could be modified to be closed loop systems.

<figref idref="DRAWINGS">FIG. 12</figref> shows a rotatable cage embodiment in which a cage <b>142</b>, which may be formed of a plurality of wires <b>130</b> to provide openings for the passage of air, but it could also be formed of a solid material which is provided with a plurality of openings. The cage <b>142</b> is mounted on an axle <b>132</b> which is rotatably mounted in bearings in standards <b>134</b>. The cage <b>142</b> is rotated to provide agitation of the mail items to remove particulate matter from the inside or outside of the mail. The cage <b>142</b> is mounted in a housing <b>136</b> which has an air inlet <b>138</b> and an air outlet <b>140</b> so that when air is moved through the housing while the cage is rotating, it will entrain particulates of hazardous material and be carried by the air. Thus, when the air stream is provided, the particulates are entrained in the air stream and removed. The arrangement of air inlet and air outlet can be changed as and when desired. The air outlet <b>140</b> is connected via the duct <b>128</b> (<figref idref="DRAWINGS">FIG. 11</figref>) to the instrumentation where sensors determine whether or not hazardous material is present.

The housing <b>136</b> has an opening, closable by a door such as is shown in <figref idref="DRAWINGS">FIGS. 13 and 14</figref>, or as shown in <figref idref="DRAWINGS">FIGS. 3</figref>, <b>4</b>, <b>6</b>, <b>9</b> and <b>10</b>.

Thus, in operation, a rotating perforated cylindrical cage is provided within a sealed container into which the suspect contaminated media is placed. The cylinder is rotated through a mechanical drive. The particulates are dislodged primarily through tumbling and secondarily through centrifugal force. Dislodge particles are entrained into an air stream and pass through a detector as described above.

<figref idref="DRAWINGS">FIG. 13</figref> shows a housing <b>144</b> having a shaker surface <b>146</b> which is driven by shaker drivers <b>148</b>, or a similar physical vibration source, attached to shallow box <b>150</b> mounted on a slight angle, approximately 20 degrees in this nonlimiting example, within the housing <b>144</b>, the box <b>150</b> having openings <b>152</b> therein. The suspect contaminated media is contained in a hopper (not shown) located above the box <b>150</b> with the shaker drivers <b>148</b>, and which feeds the mail into the housing <b>144</b> through an opening <b>154</b>. This opening <b>154</b> may have a door of the type shown in some of the previous figures. The mail passes into the lower section of the housing <b>144</b> (or exit as indicated in <figref idref="DRAWINGS">FIG. 11</figref>) only by sliding over the shallow box <b>150</b> to the bottom of the chamber where the mail passes into the exit. The shaker table drivers <b>148</b> vibrate the box and liberate the particulates. Air flow caused by inlet <b>156</b> and outlet <b>158</b> from within the vibrating box carries away the particulates to the detector arrangement <b>126</b> as shown in FIG. <b>11</b>.

<figref idref="DRAWINGS">FIG. 14</figref> shows a variation of the <figref idref="DRAWINGS">FIG. 13</figref> embodiment using a corrugated top surface <b>160</b> for the vibrating box <b>150</b> to aid in separation of the particulates from the suspect media moving over the box.

This allows the liberation of suspect particles through use of a rotating cage, or a vibrating surfaces with openings, to isolate the suspect particle detection prior to introduction to a document sorting process.

<figref idref="DRAWINGS">FIG. 15</figref> is a diagrammatic view of the steps of the process that takes place with the apparatus of the present invention.

There are two types of rotating cage arrangements shown, although other arrangements are possible and these are just two nonlimiting examples. One type is a hex cage and the other is a basket cage. In one series of embodiments, the cages are in the form of baskets which are easy to be carried by a worker.

The operation proceeds generally as follows in one, nonlimiting example of an embodiment of the invention. Air enters <b>90</b> through an inlet and passes through a 5 micron intake air filter <b>92</b>. The air flows <b>94</b> to a sealed chamber with a rotating agitator <b>96</b>. The air then flows <b>98</b> to a sensor suite or particle size sensor unit <b>100</b>. It leaves the suite <b>100</b> and flows <b>162</b> to a 0.3 micron HEPA exhaust air filter <b>164</b>. The air exits the filter <b>164</b> and flows <b>166</b> to a blower <b>168</b>, and then exits at <b>170</b>.

<figref idref="DRAWINGS">FIG. 16</figref> is a schematic isometric view of a module <b>118</b> being loaded with mail by a worker into the module, the cage being a hex basket type rotating cage as shown in FIG. <b>17</b>. The door <b>21</b> is shown in the open position.

<figref idref="DRAWINGS">FIG. 17</figref> is a schematic isometric view of a hex basket type rotating cage <b>172</b>. The basket has six sides <b>174</b>, one of which has a loading and unloading opening <b>176</b>. There is a door (not shown) for closing the cage before it begins rotating.

<figref idref="DRAWINGS">FIG. 18</figref> is a housing <b>184</b> for the hex basket rotating cage <b>172</b>. It has a front door <b>186</b> for access, as well as a loading and unloading door <b>21</b>. The cage can be seen in place in its operating position.

<figref idref="DRAWINGS">FIG. 19</figref> shows some details of the hex basket cage <b>172</b> including two of its sides <b>174</b> and a joint <b>188</b> where the adjacent sides are joined. The sides have perforations <b>190</b> and the cage is mounted on an axle <b>192</b> for rotating movement. The cage is driven by a motor <b>194</b> (<figref idref="DRAWINGS">FIG. 17</figref>) which drives a pulley <b>196</b> for driving a belt or chain <b>198</b> which drives a pulley (not shown) on the cage axle.

<figref idref="DRAWINGS">FIG. 20</figref> is a schematic isometric view of a tote basket rotating cage <b>178</b>. There are sides <b>180</b> which form the container and a hinged door <b>182</b> closes the cage when rotation is about to begin. The cage is driven in a similar manner to that described in connection with the hex basket cage <b>172</b> of FIG. <b>19</b>.

<figref idref="DRAWINGS">FIG. 21</figref> is a housing <b>218</b> for a tote basket rotating cage <b>178</b>. It has a front door <b>220</b> for access, as well as a loading and unloading door <b>21</b>.

Thus, in one aspect of the present invention there is a rotating perforated cylindrical cage provided within a sealed container into which the suspect contaminated media is placed. The cylinder is rotated through a mechanical or other type of drive. The particulates are dislodged primarily through tumbling and secondarily through centrifugal force. Dislodged particles are entrained into an air stream and pass through a detector.

In another aspect of the present invention there is a shaker table driver, or similar physical vibration source, attached to a shallow box mounted on a slight angle,, which in a nonlimiting example may be approximately 20 degrees, within a container. The suspect contaminated media contained in a hopper above the shallow box with shaker driver, passes into the lower container only by sliding over the shallow fabricated box. The shaker table drivers vibrate the box and liberate the particulates. Air flow from within the vibrating box carries away the particulates to the detector.

In a further aspect of the present invention, which is a variation of that described in the preceding paragraph, uses a corrugated top surface for the vibrating box to aid in separation of the particulates from the suspect media moving over the box.

Previous attempts to handle articles having hazardous particulates therein or thereon integrated the liberation device with the detection device. The present invention separates the two processes and incorporates multiple liberation modules to produce a flow of “free from contaminant” mail available for sorting. This logistic method decreases cost of detection through multi-module application of the detection instrumentation and also allows technology refreshing of instrumentation while maintaining the liberation hardware. Implementing this disclosure eliminates decontamination of sorting machinery, equipment or process, in that, contaminated mail never reaches those devices.

Previously proposed systems modified mail sorting equipment to integrate detection at the sorter thereby slowing or stopping the sort process if a detection occurred. If detection occurred, the sorter had to be cleaned if detection was not a false positive.

By using the present invention, there is no interruption to the mail processing if detection occurs. No cleaning of the complex sorter is needed.

It will now be apparent to those skilled in the art that other embodiments, improvements, details, and uses can be made consistent with the letter and spirit of the foregoing disclosure and within the scope of this patent, which is limited only by the following claims, construed in accordance with the patent law, including the doctrine of equivalents.