Field of the Invention

The present invention relates to a method and apparatus for managing the destruction of information storage devices such as hard disk drives and solid-state drives.

Background of the Invention

Many businesses have a need to ensure the appropriate destruction of information. Business information may contain commercially sensitive information, client lists, emails, and sales information. Some information may be attorney privileged or protected by confidentiality obligations. Some jurisdictions have privacy obligations limiting or preventing the release of information to third parties. Some businesses work with sensitive information for which access may be restricted by law, and mishandling or unauthorized disclosure can incur criminal penalties. The intentional or inadvertent disclosure of this type of information can be reported in public media resulting in significant reputation damage and it may have other consequences.

Often information is stored in an electronic form on computers or dedicated private servers. Some businesses have dedicated file, email, database, print, application and other purpose servers for storing and sharing electronic files amongst authorized persons. Those servers may have multiple data storage devices, typically hard disk drives (HDD). To protect against inadvertent data loss from the failure of an HDD this information can be duplicated across multiple HDD in a redundant array of independent disks (RAID). The information can be backed up onto a portable storage unit for storage offsite to protect against data loss in the event of server loss in a fire or other event. Those portable storage units can contain one or more HDD units.

Households can have one or more computers and typically the owners of the data on those computers do not want it shared with the world. There can be private emails and letters, household accounts, photographs and other information of a private and personal nature stored on the HDD's of those computers. This information can be stored in a RAID on the home computers and may be duplicated on portable backup drives containing one or more HDD. Households and businesses can utilise online or 'cloud-based' fileservers. Numerous cloud- based server providers take on the responsibility for managing and operating the computer servers and ensuring that their customers can securely access their data (and only their data) on the shared servers. Many companies such as Google, Microsoft, Facebook, Amazon offer services for the storage of information. Examples of these services include Office365, Amazon Cloud, and Google cloud.

Households and businesses also use cloud-based fileservers when they use various online services such as online email services as the emails are stored on fileservers contented to the internet. They access information stored on HDD when accessing the online content, such as Youtube, Netflix, iTunes, and others.

The cloud-based fileservers require large data centres for the storage of the information stored in an electronic format. The information provider may own the data centre or rely on third-party providers. Digital Realty is a large scale provider of data centres around the world. Other providers include Equinix Inc, DuPont Fabros Technology, CyrusOne and Iron Mountain. These businesses have many file servers and huge numbers of HDD used in storing information for other businesses.

An HDD has been the preferred information storage device used in household computers, backup drives and in the fileservers used at a local or cloud-based level. HDD use magnetic storage to store and recovery data from rotating disks. HDD is a reliable, low-cost storage solution and the data is retained when the HDD is powered off. Two common sizes of HDD are known as 2.5 inch and 3.5 inch which refer to the size of the disks. The drives themselves have standardized form factors, the 2.5-inch is 100 mm long by 70 mm wide and the 3.5-inch is 146 mm long and 102 mm wide. The height of an HDD can vary from 7 mm to 26 mm.

HDD can have robust aluminium or steel cases and a steel spindle which holds the disks. The disks are typically aluminium alloy or glass coated with a magnetic material and a protective coat which is normal platinum. The drive also includes a control circuit board with various electronic components and an actuator arm having a magnetic read and write head.

There has been a move towards solid state devices (SSD) for information storage, often called an SSD HDD in the consumer market. An SSD has no moving parts and provides faster access to the information. SSD are uncommon in data centres as an SSD is significantly more expensive than the mechanical HDD for the same storage. There are published concerns that SSD can lose data if they are powered off and they may have a shorter operational life.

Smartphones, tablets, laptops and other mobile computing devices provide remote access to the data stored in cloud-based or other private network accessible drives. The smartphones may be linked to home or business email accounts and other networks. A local copy of the information can be left on the device when the cloud-based information is accessed from the mobile computing device. Likewise, a copy of information created on the mobile device, such as photographs or messages, can be backed up to cloud-based storage units.

Paper documents can be destroyed within businesses by shredding or by using secure storage bins for subsequent secure destruction by third parties. Heavy duty paper shredders can be used to destroy other types of media including credit cards and compact discs (CD) and digital video discs (DVD). It is not as easy to destroy HDD, SDD or mobile computing devices.

Sometimes households or businesses may use programs to 'format' the data but this may not be effective as information can be recovered from a formatted drive. Overwriting programs can be used to repeatedly overwrite existing information but they can take a very long time to properly execute on high capacity HDD, may require the user to connect up drives to a different computer for overwriting, and are ineffective when the HDD is being replaced due to a controller failure. SSD drives can be difficult to wipe due to the way information is stored on the drive. Often households and businesses will simply remove and store the old HDD's.

Mobile phones and portal computing devices such as tablets can pose additional problems. Often, the devices are discarded when the display fails or there is an electronic failure. It may not be possible to interact with the device and instruct it to wipe the data therein.

Physical destruction can be preferred but few businesses have the required equipment to destroy an HDD. Burning the HDD can be effective but burning can release toxic gaseous. Drilling through the drive may put a hole in the data platters in an HDD, but the damaged platters can be remounted into another casing and information may be recovered. The HDD can be dissembled and the platters containing the data removed but those platters are too strong for traditional paper shredders. A shredder can have two rollers with a plurality of blades and the solid platter can jam the blades and seize up the device. The HDD case and solid steel spindle therein can cause difficulties for high powered industrial shredders. There are numerous USPTO patent applications for inventions for managing the destruction of information.

US 8229593 and 8364306 (Rodriguez) relates to a computer controlled shredder associated with an object detector. An image of the paper documents placed into a receptacle is sent to a display and a user or computer send the item to cross cut shredder. The document may include an identifier such as a barcode or RFID tag. A computer retains a record of all the destroyed identifiers. Documents can be selectively destroyed with documents on a refusal list being sent to a secure storage bin.

US 8289588 (Gural) relates to a printing station in which during printing selected confidential matters can be sent to a shredder. The shredder is fitted with a scanner to verify the contents of the document before shredding and an image of the confidential material is stored for reconciliation.

US 8851404 (Clark) describes an apparatus for destroying hard drive disks whereby a cutting tool is used to cut through the hard drive casing to the platters. Either cutting tool or HDD is rotated relative to the other part.

US 7975950 (Ebadian) describes an apparatus for crushing electronic memory media, including HDD, by using a hydraulic ram to compress the HDD.

US7240864 and 7334747 (Castronovo) relate to a paper shredder for cutting thin materials such as paper to a high-security standard.

US7600705 (Castronovo) described a conveyor belt system for feeding a non-homogeneous load of papers, CDs, smartcards and other materials into a shredder. The feed rate is controlled by load thickness sensors.

US7832666 (Montgomery) describes an apparatus for destruction of medication containers by feeding the containers into a chamber having a router bit rotating at high speed.

Many of the above do not directly address the issue of how to destroy HDD, SSD or mobile computing device. It is difficult to accomplish a consistent standard of destruction suitable for use the secure destruction of HDD. There can be prescribed standards for the secure destruction of data, if the device contained higher rated information then the device must be rendered into smaller sized particles. The US National Institute of Standards and Technology requires the shredding of optical media to particles having nominal edge dimensions of 0.5mm and surface area of 0.25mm ² . It can be difficult to achieve an appropriate level of disintegration for an HDD and in a timely manner.

Another problem is the need to destroy the information in a safe, timely and cost-effective manner. It takes time to disintegrate an HDD to a small size and some methods can release dust which may be toxic. There is a huge number of drives for destruction and any apparatus for destroying these devices must be reliable.

In order to sell machines in Australia and many other jurisdictions, the machines must comply with various regulatory standards including safety standard. In Australia, the primary requirements for machine safety for designers and manufacturers are the suite of the Australian and New Zealand standards namely the AS /NZ 4024.1 series of standards - "Safety of machinery". AS /NZ 4024.1 series of standards - "Safety of machinery" These standards are based on the structure of European standards, specifically the relevant ISO (International Organization for Standardization), IEC (International Electrotechnical Commission) or EN (European Standards) standards. The AS (/NZS) 4024.1 series provide a framework for designing and operating safe machine systems.

Traditionally, industrial shredders have been used to treat electronic waste. The industrial shredder can operate by using claw-like knives to cut articles into smaller pieces. However, those knives are not well suited for processing hard disk drives as they contain a large spindle of steel which can damage the knives and force frequent services and replacement.

Shredder systems can be put in trucks for mobile processing of electronic waste. However, smaller shredders are not efficient and may not be capable of processing HDD. Smaller shredders can jam and have other reliability issues. The shredders can take several minutes to process a single HDD, and this can generate significant heat requiring the shredder to cool down for a period of time before it can be used again.

Hammer mills have been used in to process e-waste at fixed locations. The mills are large, require substantial power to drive the mill and discharge can be further processed with cyclonic separation to separate small pieces according to their density, and magnetic separators. It is used to recover precious metal with acid washes and scrubber tanks, electrolysis systems and wastewater treatment. The treatment plants are large, and managing dust may not be an issue at fixed locations.

Hammer mills have not been suitable for mobile applications, their method of operation can create substantial amounts of dust. Electronic waste has been associated with adverse human health events, some researchers have suggested that workers in e-waste dumps can suffer from inflammation, stress, heart disease and cancer from air born e-waste. It is possible that HDD may contain heavy metals. It is unclear whether the dust from pulverizing an HDD would be harmful when inhaled but appropriate precautions are required.

Summary of the invention

The present invention provides an apparatus for the destruction of information storage devices such as hard disk drives, solid-state drives, USB flash drives and mobile phones. The apparatus includes: - a) a device receptacle capable of receiving storage devices intended for destruction; b) a device sensor capable of collecting information regarding the storage device intended for destruction;

c) a controller operationally associated with the device sensor;

d) a hammer mill capable of destroying storage devices, the mill including

i) a mill feed opening capable of receiving a storage device for milling;

ii) a milling chamber operationally connected to entry opening, the chamber containing hammers attached to a drive shaft, and

iii) the milling chamber having discharge opening fitted with a screen;

e) a discharge receptacle operationally connected to the discharge opening of the hammer mill;

f) a reject receptacle capable of storing rejected storage devices;

g) a chute, having an entry operationally connected to the device receptacle, and an exit operationally connected with the mill feed opening, and another exit operationally connected with the reject receptacle; h) the chute including a gate operationally associated with the controller, the gate capable of directing a storage device passing through the chute entry to the reject receptacle or to the mill feed opening;

i) the operation of the gate is controlled by the controller by reference to information received from the device sensor, whereby the gate directs any storage device to the exit operationally associated with the reject receptacle unless the device is recognized and authorised for destruction by the controller, whereby the gate directs the storage device to the mill feed opening.

Preferably the apparatus is located within the body of a truck.

Preferably the gate limits the egress of dust formed when milling storage media through the chute entry.

Preferably the chute includes a brush seal proximate to the chute entry.

Preferably the hammer mill is located within a region having a positive air pressure relative to the surrounding environment.

Preferably the discharge receptacle is connected to at least one source of reduced pressure, more preferably a HEPA vacuum cleaner.

Preferably, in operation, the low-pressure source induces a vortex within the discharge receptacle.

Preferably the discharge receptacle is located in a different compartment to the mill.

Brief description of the drawings

Figure 1 is a schematic representation of one side of a truck containing the destruction apparatus of the present invention. The relative location of the equipment on the other side of the truck is shown in dotted outline.

Figure 2 is a schematic representation of the other side of the truck shown in figure 1. The relative location of the equipment on the opposite side of the truck is shown in dotted outline.

Figure 3 is a schematic plan representation of the truck shown in figure 1. The relative location of the equipment not visible from above is shown in dotted outline. Figure 4 is a schematic representation of operator's compartment of the truck shown in figure 1. The relative location of the equipment present in the machine room is shown in dotted outline.

Figure 5 is a view of the operator's compartment of the truck shown in figure 1.

Figure 6 is a schematic representation of a portion of the destruction apparatus shown in figure 1.

Figures 7 to 10 are schematic cut away representations of the chute and gate portion of the destruction apparatus shown in figure 6.

Figures 11 and 12 are schematic representations of a discharge receptacle for receiving and storing the discharge from the apparatus shown in figure 1.

Detailed Description

The present invention involves using a hammer mill to destroy storage media whilst suppressing the dust generated by milling the media. The hammer mill is mounted in a truck to enable the destruction of storage media at the customer's worksite.

In brief, HDDs or other types of media are loaded into an operator compartment of a truck. If the drives do not have unique indicia then an operator may place a barcode on each hard drive before each drive is placed onto a conveyor belt where the hard drives will be scanned and photographed before falling into a hammer mill and are pulverised into small particles. Those particles fall into a discharge receptacle (bins) located under the truck. The operator can store the bins containing the particles in the operator area on completion of the processing task.

The hammer mill can be driven by a motor located in a machine compartment of the truck. The mill is fed via a conveyor belt from the operator compartment.

Dust from the hammer mill is controlled by a number of arrangements including the use of positive air pressure in the machine compartment.

A non-limiting embodiment of the invention will now be described with reference to the figures. With reference to figures 1 to 5, there is provided a truck (1) with a vehicle cabin (3) and an enclosed truck body (5).

The truck (1) can be any appropriate vehicle capable of transporting the apparatus. A suitable vehicle is the Hino 300 series - 917 Truck, 8.5-ton truck with a 110 kW diesel engine and rated for loaded gross vehicle mass of 8.5 ton. The truck has approximate dimensions of a width of 2.3m, a height of 3.5 and overall length of 6.4m.

The truck body (5) has three distinct compartments, namely the machine compartment (7) accessible via a door (9), the generator compartment (11) accessible by a wall access panel (13) and the operator compartment (15) accessible via the rear door (17). The door (17) is preferably connected to a sensor associated with a controller (123). The controller triggers an automatic shutdown of the machinery whenever the sensor indicates that machinery room door (9) is opened.

The machine compartment (7) is the forward compartment of the truck body and it contains the processing equipment and machinery. At the rear of the machine compartment, there is a wall (19) which separates this compartment from the rear compartment - the operator compartment (15). Separating the operator (21) from the machinery provides for a safer workplace and helps reduce the machine noise to which the operator (21) is exposed.

The generator compartment (11) is substantially located within the machine compartment (7) but it bridges the wall (19) into the operator compartment (15). The arrangement allows the operator (21) to access the front generator control panel (25) of a generator (23) located within the generator compartment (11) from the operator compartment (15). The operator may have direct access to the generator control panel (25) or it can be closed off by an access panel (not shown). In the depicted embodiment the opening in the wall (19) is smaller than the generator (23) and the generator control panel (25) abuts against the opening in the wall (19) and walls off access to the generator compartment (11).

The generator compartment (11) can be completely closed off if direct access to the generator control panel (25) is not required. Direct access may not be required if the generator can be monitored and controlled by way of a remote system. The generator (23) is an onboard diesel alternator set capable of powering the complete system if local facility power is not available. General access to the generator compartment is closed off from the operator and machine compartments and is generally not accessible to the machine operator.

The generator compartment (11) can be accessed via the panel (13) in the external wall of the truck body (5). This allows access to the generator (23) for service and maintenance. Some maintenance can be done via the access panel (13) but more substantial maintenance or repairs may require full access to the generator (23). This facilitated by locating the generator (23) on a support platform (not shown), which can be raised by a forklift via lifting eyes (29) so that the generator and support platform can be removed from the truck body (5).

The generator is not always required as the machinery is capable of drawing power from site facility. Site power is the preferred method of powering the equipment as it reduces noise, heat and fumes. However, having a generator in the truck allows the use of the apparatus at work sites where there is insufficient power. The power requirements of the apparatus require the use of 3 phase power, which may not be available at some sites.

Any appropriate generator can be used. In an embodiment, the generator is a 30 kVA (24kW) diesel generator such as a Kubota KJ-T300 generator. This generator is well suited for this application for provides adequate power for the other equipment and because it is designed for single-sided access for quick inspection and easy maintenance. It is provided with a sound attenuated enclosure for reducing noise levels and it includes a support platform to which lifting eyes (29) can be fitted for forklift transportation.

This generator provides 24 kW, 3 phase power, 41.7A, 50 Hz 240/415 V. The generator has a 68L diesel tank which would provide run time at full load 8.8 hours. This tank can be independent to the truck tanks.

In a preferred alternative the generator can be supplied with diesel fuel directly from the truck fuel tanks. The fuel is stored only in the trucks fuel tank and is drawn from the trucks tanks and supplied to the generator by a high-pressure pump and the excess returned to that tank using a standard fuel pick up and return. This tank can be plumbed into the truck fuel tank (31) and the Hino 917 has a 170L capacity tank. As an alternative to a dedicated generator, the truck can be fitted with a standard power takeoff (PTO) from the truck transmission. This PTO can then be used to drive the hammer mill. A split shaft arrangement mounted to the trucks drive shaft can power the PTO. This PTO can only be engaged when the vehicle is stationary and the truck engine is then used to drive the mill via an intermediate transmission. The Hino 300 series 917 truck has a HOkW diesel engine which provides sufficient power to drive the hammer mill. An electric motor can be connected to the PTO drive to provide electric power for the electrical equipment, or a small generator or single-phase power from the facility may be sufficient to power the other devices.

Noise can be an issue and the generator compartment (11) should muffle the sound of the generator when it is in use. The compartment (11) can be lined with noise muffling material.

Some of the air flowing into the generator compartment (11) comes from the machine compartment (7). The generator compartment (11) has two air vents (33, 35) which permit air to flow from the machine compartment (7) into the generator compartment (11) and out under the truck. The arrowheads (37) on figure 2 depict the movement of air through the vents into the generator compartment (11), which flows (39) past the generator into the vent cover (41) and out of the truck (43). The arrangement helps flush the heat and any exhaust gases which may otherwise collect in the generator compartment. The generator compartment (11) also draws air from a vent (44) located under the flow at the rear of the truck and the arrowhead (38) shows depicts the move of this air.

Sensors monitor the generator and automatically shut it down if abnormal conditions are detected.

The machine compartment (7) includes two intake fans (45) which draw in air from outside of the truck through the cowling (47) at the top and front of the truck body (5). The direction of the air flow through the cowling is shown by the arrowheads (49) in fig.2. These intake fans ensure that the machine compartment (7) has a positive air pressure relative to the surroundings. Each fan draws at least 3600 m ³ / hr.

The air in the machine room can flow into the generator compartment as earlier discussed. The air vents (33,35) may contain air filters which capture any dust in the air. These filters can be removed and cleaned as required. This arrangement of overpressure and venting through the generator housing should prevent the accumulation of carbon monoxide in the machine room should the generator leak carbon monoxide.

The arrangement also controls dust or any other airborne containments formed or released when the storage media is pulverized in the machine room (7). Any contaminated air passes through the filters in the vents (33,35) before venting to the atmosphere. It does not enter the operator compartment (15) which is largely sealed off from the machine compartment (7).

The machine compartment (7) includes a hammer mill (51), which is used to pulverize the storage media including HDD. The mill is mounted on a rubber mat (52) to minimize transfer of vibration to the operator. It also helps reduce mill noise.

Hammer mills are used in the mining industry to reduce raw materials into smaller particles. The hammers are attached on pivots to a rotating drive shaft or drum, which rotates at high speed about a central axis. The materials are reduced in size by contacting rapidly moving hammers within the milling chamber, and collision with the walls of the grinding chamber, and with other materials in the chamber. Materials of an appropriate size will pass through a screen over the exit, otherwise, they remain in the milling chamber and continue to be processed.

Hammer mills are more reliable than shredders, longer lasting and relatively simple to operate and maintain. In general, an operator needs to inspect and replace the hammers from time to time, check the condition of the contact wear plates, screen and ensure drive shaft bearings are lubricated. It is expected that the mill will have an operational life of at least 20,000 hours. As the wear plates and hammers are worn down they can be replaced. Normally the hammers can be fitted in a reversed configuration such that what was the trailing surface becomes the contact surface.

As HDD are very hard and mostly metal, they are comparatively difficult to process relative to friable materials. Some parts are friable and will break down to a particle size significantly smaller than the screen size. Most of the metal parts are unlikely to break down beyond the screen size such that the average particle size distribution will be close to the screen size. The mill can be fitted with 5/8 inch or ½ inch screen. With HDD these screen sizes provide a milled product having a particle from dust to have a maximum size of about 12 mm. The information containing parts of a HDD, such platters and chips will be at the smaller end of the scale. A smaller sized screen can be used to provide smaller sized products and this can be useful when treating storage media containing highly sensitive information.

In order to be effective on an HDD, the hammers need to be moving at high energy, and this is achieved by rotating the mill's drive shaft at a very high speed. However, these high-speed impacts cause problems notably noise and dust, and these are significant in a confined space, such as mobile, truck-based, media destruction apparatus. For this reason, it has been preferred to use shredders in mobile destruct apparatus or relocate the storage media to a large treatment plant.

It is expected a broad range of commercial hammer mills could be used in the present invention. In a preferred embodiment, the hammer mill is a 12-inch wide hammer mill and is rated for up to 25 hp (20 kW) and is capable of at least 3600 rpm.

It is possible to use a smaller mill, such as an 8-inch mill or a larger mill, such as a 16 or 25- inch mill. A smaller mill will take longer and larger mills require larger motors and may require a larger generator. The 12-inch motor requires a driving motor providing approximately 15 horsepower (11 kW).

In figure 6, the driver pulley wheel is fitted to the electric motor (53) and is connected by a drive belt, such as a vee belt, to the driven pulley wheel mounted on the driveshaft of the hammer mill (51), and transmits power to the mill. The pulley wheels and vee belt is not shown for it is covered by a belt guard (55). Other drive arrangements may be possible instead of the v belts, such as chain drive, sprocket drive or a direct connection.

The driving electric motor (53) draws power from either the generator (23) or the site facility. Preferably the electric motor is controlled by a variable speed drive. This is better for the system for it requires a smaller generator to manage peak power demand at start-up of the mill. A 3 phase Techtop Australia motor TCI-160 can provide the requisite driving power.

The rotational speed at which the motor can drive the mill depends on the power of the motor and the diameters of the pulley wheels and the frequency of the incoming supply. In an embodiment, the driver pulley wheel is capable of 1480 rpm and is capable of driving the driven pulley wheel of an unloaded hammer mill at 3600 rpm, such that the hammers within the mill are rotating at 3600 rpm.

It is expected that the drive belt tension will need to be checked every 500 hours.

Alternatively, the electric motor (53) could be replaced with a PTO from the truck engine and with a gear box.

The apparatus includes new and innovative elements to manage dust and which enable the provision of a mobile apparatus capable of safely destroying of storage media at the customer's facility.

As previously mentioned the machine compartment (7) has a positive air pressure from the intake fans (45) relative to the surrounding environment. Any dust from the mill (51) in the machine compartment should be captured within the filters in the vents (33,35).

The chute (61) also assists in controlling the release of dust from the mill (51). The chute (61) is fitted above the upper feed opening (63) of the hammer mill (51). The chute (65) has three openings, the lower exit connected over the feed opening (63) of the mill, the top entry (65) and an intermediate opening, the reject exit (67).

Any dust leaving the mill via the feed opening (63) must pass upwards against gravity through the chute.

The chute entry (65) is fitted with a brush seal (69) to control dust and the machine room is under positive air pressure, which further controls the egress of dust into the machine room (7).

The chute contains a gate (71), shown in the closed position in fig 6. and it can be moved to an open position (73) by way of a pneumatic actuator (75). An oil-less compressor (74) located in the machinery compartment is used to supply air to the pneumatical actuator (75). Other types of actuators can achieve the same outcome.

In the default position (71) the gate closes off the mill and storage media will not pass into the mill. The gate only opens to allow an HDD intended for destruction to pass down the chute into the mill and closes shortly thereafter. It remains closed until the mill is ready for next HDD intended for destruction. When closed the gate acts as a seal to control the egress of dust past the gate into the machine room.

The mill (51) includes at least one sensor capable of directly or indirectly monitoring the rotational velocity of its drive shaft. A suitable sensor can include a Hall effect sensor associated with the driven pulley wheel on the drive shaft. The sensor can be used to determine the rpm of the driven wheel. The rpm of the drive shaft (and attached hammers) is normally shown on a tachometer in the operator compartment (5).

When the mill is processing an HDD the rotation of the hammers and drive shaft can decrease as compared to the unloaded rpm. Once the HDD has been processed the rpm will return to the unloaded speed as the drive shaft is driven by the driving motor. The sensor for monitoring the drive shaft will indicate when the rpm of the hammers in the mill is decreasing or increasing.

A controller can monitor the rpm via the rpm sensor and only open the gate (71) to allow another HDD to be fed into the mill when the mill has largely finished processing the previous HDD. Preferably the gate is opened and another disk fed into the mill when the drive shaft is at 3400 rpm and climbing. This arrangement avoids overloading the mill and also helps to control the egress of dust by sealing off the mill until it has largely finished processing the earlier HDD.

A 12-inch mill can take 4 seconds to process a 2.5-inch HDD (110 grams) and 12 seconds to 20 seconds to process a 3.5-inch HDD (270 to 750 grams).

The hammer mill can be fitted with other sensors including a sensor to monitor vibration levels. The sensors are used to monitor against unbalanced machinery or other undesirable conditions. The mill may include a heat sensor on drive shaft bearings and noise sensor.

With reference to figure 1, dust is also controlled by having the gravity discharge opening (80) of the hammer mill connected by a flexible pipe (82) passing through the floor of the truck and securely attached or clamped to the discharge connector (78) of a discharge receptacle (77) located under the truck. This arrangement avoids the need to open the discharge container within the machine or operator compartments of the truck. The discharge container can be attached to the underside of the truck or, as depicted, it can be a separate, mobile container. Customers may prefer to see the discharge container located outside as the customer can hear the discharge going into the container, and easily inspect the pulverized HDD. The typical discharge container or refuse bin may be 600 mm width by 600 mm length by 400 mm height and a lid which can be tightly sealed to the container. A container of these dimensions should be able to store the pulverated remains of about 1400 2.5-inch HDD, which is about 1 day of work.

Dust is further controlled by fitting the lid of the discharge receptacle is fitted with at least one vacuum hose connector (79), which are connected by flexible pipes (83) to vacuum cleaners (85). Preferably the vacuum cleaners are high-efficiency particulate air (HEPA) vacuum cleaners (85). The HEPA cleaners can be wired to automatically activate whenever the mill is operating. Two HEPA dust extraction units (85) are shown in the machine compartment and the filtered exhaust air blows into the machine compartment.

Most of the discharge (89) within the container (77) should be of a particle size similar to the screen fitted to the mill. However, the mill (51) will produce much smaller particles including dust, and the dust may include materials which could impact on the health of anyone who inhales the dust. The HEPA vacuum cleaner will assist in removing the dust from the air and capture the dust within the HEPA filters for later removal.

The twin dust extraction units are connected to two hose connectors (79) above the container lid and preferably located the near perimeter of the lid and preferably on opposite sides of the discharge connector (78). The nozzles (81) can be plain nozzles or preferably, are directional and orientated in the same direction, all clockwise or all anti-clockwise. This arrangement of drawing of air near the perimeter and inflow of air near the centre can induce a vortex, shown by the arrows (95) in Fig. 1. within the container and about the discharge connector (78). Airborne dust passing into the container (77) from the mill (51) should be captured by the dust extraction units (85). The heavier discharge particles collect in the container (77).

Accordingly, dust within the truck is further controlled by positive air pressure flowing into the machine compartment (7) flows into the mill (51) into the container (77) and then into the dust extraction units (85), which has a negative air pressure. The HEPA dust filtration system can be fitted with a sensor monitoring the device suction. An alarm can be raised if the suction too low which may indicate a HEPA filter should be cleaned or replaced.

The vortex caused by the dust extraction HEPA vacuum can also assist by dispersing the pulverized HDD (89) over a greater area within the discharge container (77). If the container has the remains of previously processed devices (89) then this arrangement can assist security by mixing together the remains of the new device with the remains of earlier ones to make it difficult to recover the components of a single drive.

The discharge container (77) includes a pyramidal frame (91) therein. The frame (91) supports a magnetic separator (93). Non-ferrous discharge (89) entering the container (77) via the connector (78) can contact and be deflected by the magnet separator (93), spreading the HDD materials throughout the container (77).

The magnetic separator (93) can be of use or in collecting rare earth magnets from the discharge (89) for further processing. The frame can operate as a magnetic claw for removing magnetic components. Rare earth permanent magnets are used in the spindle motor of the HDD (the part that spins the platters), and voice coil actuator (the part which moves the read / write head) of a HDD.

The magnetic separator (93) is preferably a switchable permanent magnet. The switch mechanism keepers the magnet by mechanically rotating a secondary permanent magnet to suppress magnet flux of the first magnet, or uses an electromagnet to achieve the same suppression.

The discharge (89) has some recycling value. An HDD has copper, silver and gold connectors. It is possible to process and recover those metals from the discharge (89).

The portable discharge containers (77) can be stored in the operator compartment (15) when the apparatus is not in use. The containers (77) can be securely stored in this compartment during transport.

The rear of the truck is may be fitted with a self-contained electro or hydraulic tailgate loading system (not shown). This lifter can facilitate loading of containers of storage media and loading or unloading of containers (77) into the operator compartment. A suitable lifter is produced by D'hollander and has a nominal load of 600Kg. When the truck returns to home base, the containers (77) can be unloaded from the truck using the tailgate loading and emptied, and the contents stored for recycling.

The tailgate loading systems are well known and can include an external control box near the rear of the truck or a handheld controller can also be plugged into control port or may operate wirelessly. The system can include a hydraulic power pack containing an electric motor, a hydraulic pump, oil tank and the control valves is located on the vehicle chassis behind the control box. The control box and the hydraulic power pack are connected to the vehicle battery. Before use, a lift platform is folded-out from its travel position under the vehicle chassis to a functional (working) position behind the vehicle body.

The operator compartment (15) is located at the rear of the truck (1) and the operator (21) enters the compartment (15) via the rear door or gate (17) of the truck.

All operator controls are within the operator compartment (15) and the rear door of the truck is normally open when the apparatus is in use. For comfort, the operator compartment preferably includes the header unit of an air conditioning unit (95) which is connected to a compressor (97) located in the machine compartment.

The operator compartment (15) includes a window (101) into the machine compartment (7) in order to allow the operator (21) to visually monitor the situation therein. The machine compartment (7) also includes numerous sensors including those previously mentioned in relation to the mill (51). The sensors include smoke detectors, temperature, ventilation and air quality sensors (not shown). These sensors are monitored and the equipment in the machine room will shut down if the monitored parameters fall outside those permitted for continued safe operation. For example, the CO sensor will monitor CO levels in the machine compartment and shut down the machinery if the CO is over 150 parts per million. The rpm of the mill drive shaft would be shut down if the mill speed dramatically drops indicating a jam.

With reference to figure 5, the operator compartment (15) includes a device receptacle (103) for receiving a storage media. The dimensions of the device receptacle (103) are set to prevent the placement of devices larger than the capacity of the mill (51). In a preferred embodiment it does not permitted the insertion of media substantially larger than a single 3.5-inch HDD.

A conveyor system conveys storage media placed in the device receptacle (103) located in the operator compartment (7) to the chute entry (65) in the machine room (15). The conveyor system includes a continuous feed belt (105) located between two rollers (107, 109). The direction of travel of the belt (105) is shown by the arrowheads (110) in figure 6.

The belt (105) is fitted with transverse lugs or cleats (111). The transverse cleats provide sections or pockets (112) into which the storage media (113) can be placed. The conveyor system also includes a drive motor (not shown) connected to one of the rollers and controlled by a control system (123).

Below the conveyor system is a return chute (124) connected to reject exit (67) of the chute (61). With reference to figures 7 to 10 rejected storage media (115) can slide down the gate when it is the closed position (71) and the return chute (124) to a reject receptacle (126). The reject receptacle can be an open shelf or shelf within a storage cupboard or locked container. An open shelf can be preferred to allow the operator (21) to easily retrieve and inspect the returned storage media (117) and possibly retry its destruction. It is possible the operator incorrectly placed the media in the receptacle (103) such that it was not identified by the device sensor (121).

Proximal to the top entry (65) of the chute (61) is the device sensor (121) which is connected to the control system (123). This sensor can be used to search for an appropriate identifier on the nearby storage media. The identifier may be a barcode or radio frequency identification device (RFID) tag. The device sensor (121) may also include a camera system for recording photographs or video images of the nearby storage media.

The control system (123) uses a Programmable Logic Controller (PLC) to control all subsystems. The control system (123) collects information from various sensors including the rpm sensor on the mill (51), and the device sensor (121). The control system (123) controls the operation of the drive motor (53), the pneumatic actuator (75) and the drive motor for the feed belt (105). The control system (123) is connected via a closed communication loop to an industrial grade computer (125). The equipment cannot be operated by any person not possessing this computer and the relevant passcode to turn on the computer.

The computer (125) may be a laptop or other portable device and can be removed from the truck and held by the operator in a secure location at the conclusion of on-site destruction. The computer (125) also holds the data records from the destruction process. Optical character recognition or barcode recognition software may operate from this computer (125) or the PLC (123) to analyse the sensor information from the device sensor (121). Photographs and video images of the storage media can be saved to the computer (125) or to a separate storage device. Other information may be collected such as the time and identity of the operator using the equipment.

Commercial Industrial Protocol (CIP) communications standard equipment is employed between the system PLC and a series of sensors that control the machine and the operator's cabin. The sensors measure a series of parameters that are employed to automatically time the operation of the feed belt and the speed of the destruction mill to ensure that the mill cannot be overloaded. Other sensors monitor the environment inside the operator compartment to ensure that it is satisfactory for work.

After a session, the operator (21) can produce a report for the customer and provide an electronic copy. The report may include a list of the device identifiers, barcodes or RFID numbers, of the storage media destroyed by the mill, and those rejected by the system. Photographs and videos may be provided.

The control system (123) will only operate the feed belt if the rpm sensor on the mill (51) indicates that the mill is operating at 3400 to 3550 rpm. The control system ensures the mill is operating at the preferred speed before media can be feed into the mill.

The control system (123) will only operate the pneumatic actuator (75) and move the gate to the open position (73) when storage media is ready to be feed into the mill.

Large data centres will normally give each HDD a unique barcode identifier and those barcodes may be detected by the device sensor (121). These customers will normally provide a list of the media intended for destruction. In this approach, the identity information of the storage media obtained from the device sensor (121) is compared with a list of identifiers authorised for destruction. If the identity information obtained from the device sensor not on the list or cannot be detected by the sensor, the control system (123) operates the feed belt but does not operate the pneumatic actuator (75). The gate remains in the closed position (71) and the rejected storage media (115) slides down the gate (71) and return chute (124) and is delivered to the reject receptacle (126). If the identity information is on the list the control system operates the feed belt and operates the pneumatic actuator as shown in figure 9, so the storage media (119) could fall into the mill.

In another approach the storage media has identifiers but the customer does not have a list of those unique identifiers. When the identifier can be detected by the sensor, that information is stored in a list and the media proceeds to destruction. Any media without an identifier is rejected. The customer is provided with a list of processed media as well as any rejected media. The total number of processed and rejected media can be compared with the total number of media provided for destruction.

Some businesses may not have put unique identifiers on their storage media. In this approach when the media is collected, the operator (21) will count the media and provide a receipt for the counted number of media. For tracking purposes, the operator (21) may optionally add a barcode to each media, but this may not be required by the customer. The customer may be satisfied by a report listing the media which has been destroyed together with photographs thereof.

The control system (123) or the computer (125) may produce an audit report for review by a security manager if there is an issue regarding the number of media destroyed or rejected.

The machine compartment and the operator compartment can include closed-circuit cameras, which operate whenever power is connected to the truck or when the generator is running. The operator compartment can contain a network video recorder (not shown) and monitor (129). The networked video may be saved on the computer (125). The closed-circuit system provides a visual audit trail of the processing session and enables the video files of the session to be supplied to the client together with the report of items processed.