WO2021150833A2

WO2021150833A2 - Portable labware frost remover

Info

Publication number: WO2021150833A2
Application number: PCT/US2021/014531
Authority: WO
Inventors: Joseph P. GOMEZ; Ali AKAR; Gordon Andrade; Tyler MELLO; Jonathan Swenson
Original assignee: Hamilton Storage Technologies, Inc.
Priority date: 2020-01-24
Filing date: 2021-01-22
Publication date: 2021-07-29
Also published as: EP4093546A2; EP4093546A4; WO2021150833A3

Abstract

A labware frost remover removes frost from laboratory tube storage racks, and from tubes stored in the racks to expose barcodes. The rack frost remover wets a rotating brush and conveys the frosted rack over the rotating, wetted brush to remove frost on contact. The rack frost remover also sprays de-icing fluid on the leading wall of the conveyed rack. The de-icing fluid is a mixture of isopropyl and propylene glycol, with an optional fragrance. The rack frost remover can optionally include a scanner or camera for reading barcodes after frost has been removed.

Description

PORTABLE LABWARE FROST REMOVER

FIELD OF THE INVENTION

[0001] This invention relates to the removal of frost from frozen, filled or partially filled, tube storage racks or boxes, and the bottom of sample tubes and vials stored in the racks or boxes.

BACKGROUND OF THE INVENTION

[0002] Storage of biological and chemical samples is widespread in the life science industry. Many samples are stored in freezers often well below the normal freezing temperature. Generally speaking, a regular freezer operates from about -5°C to -20°C, whereas an ultra-low temperature freezer operates from about -50°C to about -130°C (preferably at about -80°C), and a cryogenic freezer operates from about -140°C to about -196°C (the boiling point of liquid nitrogen). Biological samples are often stored in ultra-low temperature (e.g., -80⁰ C) or cryogenic freezer systems.

[0003] It is common to store samples in sealed, plastic laboratory tubes held in storage racks in arrays of for example 24, 48, 96 or 384 tubes. Sometimes the storage racks includes lids or covers, in which case the racks are typically called boxes or cryo-boxes. Lids are used in manual freezer systems, but are normally removed when the rack is stored in an automated system. The industry has developed many types of automated equipment to handle these storage racks and sample tubes. The American National Standards Institute/Society for Laboratory Automation and Screening (ANSESLAS) has adopted standardized dimensions for microplates, which are used for many tube storage racks. Earlier versions of these standards were previously referred to as SBS format.

[0004] The 96 format is widely used with microtube storage racks. Most 96 tube storage racks are manufactured to have the same footprint (127.76 mm by 85.48 mm) as the ANSESLAS (formerly SBS) microplate standard. This means it is convenient to handle the racks with automated equipment, and makes it possible to store the storage racks on shelves sized to hold standard microplates. The storage racks normally contain receptacles for holding the microtubes in the same array and positions as the wells in a standard microplate. This again facilitates use of automated equipment when processing microtubes. A bar code is often printed on the sidewall of the rack, or printed on a label that is adhered to the sidewall of the rack. In most cases, a two- dimensional barcode is also adhered to the bottom wall of the microtubes. The tube receptacles in the rack are typically open so that the two-dimensional barcodes are able to be read with a scanner through the bottom of the storage racks Bar coding facilitates data entry into control systems that keep track of the location and history of each of the biological samples. Bar coding is useful when using either manual or automated freezer systems.

[0005] When storing life science labware, such as tube storage racks or boxes, in ultra- low temperature (-80 ⁰ C) or cryogenic environments, any moisture introduced to the labware creates varying levels of frost and ice. The amount of frost and ice depends on the duration and frequency of exposure to the moisture. Frost makes it difficult or impossible to read barcodes and can make it difficult to place tubes in the racks. In some cases, the frost accumulation can be so thick that it affects the freezer storage capacity. The term ice is used in this application to describe frozen water that interferes with the tube picking and placement process; whereas the term frost refers to frozen water that does not interfere with the tube picking process.

[0006] Lab workers are often tasked with taking inventory of samples stored in cryogenic or ultra-low temperature freezers. This requires the barcodes to be read, which is often difficult because of frost accumulation. Sometimes alcohol (isopropyl) wipes are used to manually wipe down the bottom of frosted tube racks, in order to remove frost from the bottom of the racks and expose the barcodes on the bottom of tubes stored in the racks, before placing the racks on the scanner. Alcohol (isopropyl) wipes are also used to manually wipe the sidewall of the rack to expose any one-dimensional bar code on the respective sidewall. Repeated wiping of racks by lab workers is not particularly desirable. The additional handling of the rack means that the samples are likely to be exposed to ambient conditions for a longer period of time when transferring, e.g., from a manual freezer to an automated freezer system. It also subjects the rack to human error and heat transfer from hands and fingers. The isopropyl evaporates quickly; however, frost begins to accumulate on the wiped labware almost immediately upon placing the labware in the cryogenic or ultra- low temperature (-80 °C) freezer.

[0007] Rack defrosting systems are known. One type of system uses a rotating brush to mechanically remove frost from the bottom of racks and the bottom of sample tubes in the rack. These rotating brush systems work fairly well to remove frost but cannot guaranty that the bottom of the sample tubes are cleaned well enough to enable accurate reading of the 2-D bar codes on the bottom of the sample tubes. Another type of frost removal system uses a high-pressure, vertical air blade of relatively warm air which, when applied to the frost on the bottom of the tubes, removes frost by evaporation or mechanically. These air blade systems, like the rotating brush systems, cannot guaranty that the bottom of the sample tubes are cleaned well enough to enable accurate reading of the 2-D bar codes on the bottom of the sample tubes.

[0008] One object of the invention is to provide a method for quickly cleaning storage tube racks and boxes of frost so that the barcodes can be accurately and reliably read without excessive handling by lab workers, and can also be free of ice that could interfere with reliable tube picking in automated systems.

[0009] Another object is to retard the formation of frost when the labware is replaced into a cryogenic or ultra-low temperature (-80 °C) freezer.

SUMMARY OF THE INVENTION

[0010] In one aspect, the invention is a system that removes frost from filled or partially filled tube storage racks, and from the bottom of tubes stored in the racks. It quickly cleans barcodes on the bottoms of tubes and on the racks so they can be scanned. In a preferred embodiment of the invention, the frost remover utilizes a rotating brush that is wetted by spraying a de-icing fluid onto the rotating brush. The wetted rotating brush applies the de-icing fluid to the bottom of the rack and the bottom of sample tubes held in the rack as the rack is conveyed over the rotating brush. The system is capable of removing frost in 15 seconds or less from a rack filled with sample tubes frozen to an ultra-low temperature (-80 °C). This is important because it is desirable that frost be removed without allowing the samples to increase in temperature more than 15 °C (i.e., not to a temperature higher than -65°C for a sample removed from a -80 °C freezer). It has been found that a temperature rise of more than 15 °C does not occur if a rack removed from an -80 °C freezer remains in ambient conditions for less than 30 seconds. If the de-frosting cycle through the system is 15 seconds or less, lab workers should have ample time to remove the rack from the freezer or portable cooler, de-frost the rack, read the barcodes, and transfer the rack into a destination freezer or replace the rack into the source freezer or portable cooler, within the allotted 30 seconds. The exemplary embodiment of the invention can effectively defrost in 10 seconds. The invention is particularly useful when transferring large numbers of racks from manual ultra-low temperature (e.g., -80 °C) or cryogenic storage to an automated ultra-low temperature freezer system.

[0011] In an exemplary embodiment, the rack frost remover has an input station where the user places the frosted rack, and an output station where the user retrieves the de-frosted rack. It is possible that the system can be used with robotic equipment but it is contemplated that the racks will be hand placed in most applications. The rack frost remover has a housing and the racks are conveyed along a guided internal path from the input station through the housing to the output station. The guided internal path is configured for SBS-formatted tube storage racks in the exemplary embodiment. The racks are conveyed with a first and second row of rollers. The conveyed racks straddle the first and second row of rollers, with longitudinal guide rails located above the rows of rollers to guide the SBS-formatted tube storage rack along the path over the rotating brush while being conveyed by the first and second rows of rollers. The width of the brush should be sufficient to reach the entire width of the bottom of a conveyed SBS-formatted rack. Desirably, a gap is provided in the rows of rollers and the upper portion of the rotating brush engages the bottom of conveyed racks when the respective rack is located over gap. This gap provides clearance so the brush can reach the edges of the rack. The rack frost remover thus provides hands-free operation between the input station and the output station, and reduces the contact that lab technicians have with the labware.

[0012] The rotating brush has soft, pliable bristles that enable the brush to apply the de icing fluid effectively without dislodging sample tubes. The brush rotates in the direction opposite of the direction that the racks are conveyed through the housing. It is also important to consider the diameter and the mounting height of the rotating brush, particularly so that the rotating brush does not stop or slow the racks as the racks are conveyed over the brush.

[0013] The preferred rack frost remover also includes another sprayer, a rack sprayer, in addition to the brush sprayer that sprays de-icing fluid on the rotating brush. The rack sprayer sprays de-icing fluid on the leading wall of a rack being conveyed through the housing, and removes frost on the leading wall to expose any barcode located on the leading wall.

[0014] The rack frost remover can be made to be portable to facilitate use on a benchtop or on a portable cart. In this regard, it is desirable that power supply for the motors and pumps include a rechargeable battery.

[0015] In another aspect, the invention is directed to the use of a de-icing fluid comprising a mixture of isopropyl and propylene glycol, where the propylene glycol comprises approximately 5% by volume of the mixture. The use of this mixture has been found to be particularly effective. When it is applied to the bottom of the tube storage rack, the mixture removes frost and ice on contact. While other de-icing fluids may remove frost, the isopropyl/glycol mixture can be used without the addition of corrosive salts. In addition, use of the isopropyl/gylcol mixture significantly retards frost re-formation rates when the racks are replaced into an ultra-low temperature (e.g., -80 °C) or cryogenic freezer.

[0016] Another aspect of the invention is directed to the delivery of the de-icing fluid. As mentioned, the optimum de-icing fluid is a mixture comprising isopropyl and propylene glycol. The isopropyl evaporates quickly in ambient conditions. To prevent evaporation of isopropyl prior to use, the mixture is contained in a sealed container, preferably a disposable, gravity fed bag. The rack frost remover includes means to hang the bag. A feed tube connected to the bag is adapted to be connected to the inlets for the sprayer pumps in the rack frost remover. Eliminating isopropyl evaporation prior to use is important to control the concentration of the propylene glycol. Too high of a concentration of propylene glycol can cause stacked racks to stick when placed in a freezer. The gravity fed bag also preferably includes an RFID or NFC chip that contains information to identify the disposable bag. The rack frost remover preferably includes an RFID or NFC reader that reads ID data for the bag, and notifies the user when it is necessary to replace the bag of de-icing fluid based on usage. It also ensures that the rack frost remover uses the desired mixture which is optimized to quickly remove frost and also retard frost reformation when the racks are replaced in the freezers and do so without excessive sticking.

[0017] The foregoing and other aspects, objects, features and advantages of the invention will be apparent to those skilled in the art from the following drawings and description of the preferred embodiment of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a perspective view of a portable, automated rack frost remover constructed in accordance with an exemplary embodiment of the invention.

[0019] Figure 2 is a perspective view of the rack frost remover shown in Figure 1 with the top cover removed to show components within the housing.

[0020] Figure 3 is an enlarged view similar to Figure 2 also showing an exemplary SBS formatted tube storage rack with tubes loaded into the rack.

[0021] Figure 4 is an upper perspective view of internal components of the rack frost remover shown in Figures 1 through 3.

[0022] Figure 5 is a lower perspective view of internal components of the rack frost remover shown in Figures 1 through 4. [0023] Figure 6 is a longitudinal sectional view of the rack frost remover shown in Figure

1, also showing a rack with tubes within the system.

[0024] Figure 7 is a transverse cross-sectional view of the rack frost remover shown in

Figure 1, also showing a rack with tubes within the system

[0025] Figure 8 is a detailed view of the belt-driven rollers used in the exemplary embodiment of the invention.

[0026] Figure 9 is a schematic view showing the belt drive of the rollers and the rotating brush.

[0027] Figure 10 is a detailed view of the region depicted by lines 10 — 10 in Fig. 9.

DETAILED DESCRIPTION

[0028] The figures illustrate an exemplary embodiment of an automated rack frost remover

10 constructed in accordance with the invention. The rack frost remover 10 removes frost from a rack 12 and from the bottom of sample tubes stored in the rack that have been retrieved, for example, from long term cold storage in either manual or automated freezers, such as ultra-low temperature (-80°C) or cryogenic freezers. The rack frost remover 10 uses a rotating brush 14 wetted with de-icing fluid to remove frost quickly and safely, which may otherwise obscure barcodes on the racks or on the bottoms of tubes stored in the racks. The automated rack frost remover 10 shown in the figures is configured to have a small footprint and be completely mobile or portable. In this regard, the rack frost remover 10 desirably has a power supply with a rechargeable battery that enables the users to perform work using line power or battery power if line power is not available.

[0029] The portable rack frost remover 10 has an input station on which a frosted rack is set and frost is removed and delivered to an output station 18 in the hands free manner, thereby eliminating the handling of harsh liquids by laboratory workers and the inhalation of noxious fumes during the defrosting process.

[0030] The exemplary rack frost remover 10 shown in the figures is configured to accept

SBS-formatted tube storage racks (127.76 mm by 85.48 mm). While the speed of the defrosting process can be adjusted, the exemplary rack frost remover is configured so that it is possible to defrost racks that have been taken from a -80°C freezer, quickly remove frost, scan the barcodes and replace the rack into the same or different freezer environment in a time of less than 30 seconds, thereby avoiding the potential of warming samples more than 15°C while the rack is in the ambient conditions.

[0031] Referring in particular to Figure 1, the rack frost remover 10 has a housing 20 through which the racks 12 are transported from an input station 16 to an output station 18. The top of the housing 20 includes a touch screen display 22. It also includes an indentation or nest 24 for an SBS-formatted tube storage rack. The touch screen display 22 enables the user to set the speed of transporting the racks through the system. For example, if the frost on the racks is such that it is not being properly removed, then the speed of the system can be slowed by the user. The touch screen display 22 also enables the user to control sprayer activation. For example, one of the sprayers 38 (Figs. 5 and 6) sprays the rotating brush 14 while the other sprayer 42 (Figs. 3 through 7) sprays the front or leading sidewall 64 of the rack 12 as it passes through the system. If the rack 12 does not have a barcode on its leading sidewall or if it is not necessary to defrost the leading sidewall for some other reason, the user can choose to deactivate the rack sprayer 42. Also, if the user decides to use the system without de-icing fluid it can choose to deactivate both the brush sprayer 38 and the rack sprayer 42. The touch screen display 22 also provides a signal to indicate the remaining battery life as well as the remaining level of de-icing fluid (number of racks that can be processed before reloading de-icing fluid). Fig. 7 shows a controller 82 which operates the touch screen display 22, and otherwise controls the operation of the rack frost remover 10. [0032] Referring now to Figures 2 through 5, the internal components of the automated rack frost remover 10 are now described. Figs. 2 and 3 show the automated rack frost remover 10 with the top portion of the housing 20 removed. In Fig. 2, a rack 12 is shown as it is moving through the frost remover 10 at a position above the rotating brush 14. In Fig. 3, the rack 12 is shown before it is placed on the input station 16. In Figures 4 and 5, the entire housing 20 and the input station 16 and output station 18 are removed, to show certain internal components.

[0033] Longitudinal guide rails 28, 30 are provided to guide the rack 12 along the appropriate path through the rack frost remover 10. The guide rails 28 and 30 are spaced apart and parallel to each other, and are intended to provide guidance to a standard SBS-formatted tube storage rack 12 having a width of 85.48 mm or about 3.36 inches. The distance between the guide rails 28 and 30 needs to be larger to accommodate for accumulated frost on the sidewalls of the rack 12, but not so much so that the rack 12 can become misaligned. The guide rails 28, 30 are attached to a frame 32, like many other components. The rack 12 is conveyed from the input station 16 to the output station 18 between the guide rails 28, 30 by driven rollers 34, 36. A first row of rollers 34 is located generally underneath the first guide rail 28, however, the rollers 34 extend inward beyond the guide rail 28 in order to provide support for the respective edge of the rack 12 being conveyed through the system. Similarly, a second row of rollers 36 is located underneath the second guide rail 30, and likewise the rollers 36 extends slightly inward from the guide rail 30 in order to support the respective edge of the rack 12 being conveyed through the system. In the exemplary embodiment, each roll of rollers 34, 36 has sixteen (16) rollers, see Fig. 6. Each roll of rollers 34, 36 includes a gap 34G (Fig. 6) corresponding to the location of the rotating brush 14. In the exemplary embodiment shown in the drawings, there are eight (8) rollers before the gap and eight roller (8) after the gap on each side. The centerline distance between the rollers in each row 34, 36 is 25 mm except for the gap 34G occurring over the brush 14 where the centerline distance across the gap is 62.5 mm. The rotating brush 14 has soft pliable bristles. In the disclosed embodiment, the rotating brush 14 has thin nylon bristles, has an outer diameter of about 6 inches and has a width of about 3.5 inches, which means the brush 14 is wider than the footprint of a standard SBS-formatted rack. The brush 14 is mounted horizontally underneath the pathway for the rack 12 through the system, under the gap 34G. The axel 46 for the rotating brush is mounted to bracket 48, and to a similar bracket on the other side. The drive mechanism to rotate the brush 14 is described below in connection with Figures 8 through 10.

[0034] The figures show an electrical module 26 representing a printed circuit board, electrical connections other necessary electronics. The figure also show a rechargeable battery 66. A suitable rechargeable battery for this application is a lithium phosphate battery with the 24 volt output and a 10 amp hour capacity. Desirably, the system is configured to operate on line power, such as 120 volt AC power, and charge the battery 66 whenever it is connected to line power. When line power is not available, the system automatically operates on battery power.

[0035] The system includes two sprayers 38, 42. Sprayer 38 is referred to the brush sprayer

38, and sprayer 42 is referred to as the rack sprayer. The pump for brush sprayer 38 is labeled by reference number 40, and the pump for rack sprayer 42 is labeled by reference number 44. Tubing connects the pumps 40, 44 to the sprayers 38, 42. Pump 40 is activated to spray de-icing fluid though the brush sprayer 38 onto the brush 14 when it is rotating and when the controller determines it is necessary for proper operation. On the other hand, pump 44 is activated to spray de-icing fluid through the rack sprayer 42 onto the leading wall of a rack 12 entering the path through the system. Pumps 40 and 44 are centrifugal, micro pumps.

[0036] The motor 50 is a DC powered stepper motor which drives axel 52 which in turn drives belts 54, 56 to turn the rollers in the first row 34 and the rollers in the second row 36 respectively. In this exemplary embodiment the drive belts also rotate the brush 14. The rotating brush 14 can be driven by a separate motor and drive mechanism in other embodiments.

[0037] The rack frost remover 10 uses two proximity sensors 58, 60 to detect the storage rack 12 and control operation. Referring to Figure 3, a first proximity sensor 58 detects when the rack 12 has been placed on the input station 16 and scooted forward to the entrance of the guide rails 28, 30 and the rack conveying rollers 34, 36. When the first proximity sensor 58 detects the presence of the rack 12, the electronics 26 activate the motor 50 to drive the rollers 34, 36 and the rotating brush 14. As mentioned, the brush 14 moves counter-clockwise to the motion of the rack 12 through the system. The second proximity sensor 60 in the path of the rack 12 moving through the system detects when the rack 12 is in the proper range to activate the rack sprayer 42. As mentioned, the purpose of the rack sprayer 42 is to spray de-icing fluid on the front or leading wall 64 of the rack 12 in order to expose any barcode on the front wall 64 of the rack 12, see barcode on leading wall 64 of rack 12 in Figure 3. Once the sensor 60 determines that the rack 12 is within the proper range, pump 44 is activated to spray de-icing fluid from rack sprayer 42, assuming that the user has selected to use this feature on the user interface 22. The rack sprayer 42 and the pump 44 are activated for a predetermined amount of time.

[0038] Figures 2, 5, 6, 7 and 9 show the rack 12 as it is passing over the brush 14. Referring in particular to Figure 6, it can been seen that the row of rollers 34 in this embodiment includes sixteen (16) rollers and, as mentioned above, there is a gap 34G between the 8^th and the 9^th roller. There is a corresponding gap in the row 36 of roller on the other side as well. These gaps 34G provide clearance for the brush 14 to cover the edges of the rack 12 as they are conveyed on the rollers 34, 36. Figure 6 shows the spray from the brush sprayer 38 wetting the brush 14 on the downward pass as it rotates after its peak height. It should not be necessary to run the brush sprayer 38 continuously, rather the brush sprayer 38 is run periodically as deemed necessary by the controller to appropriately wet the rotating brush 14. The lower portion of the bmshl4 resides within a catch basin 68. The rotating brush 14 picks up de-icing fluid that has been caught in the catch basin 68.

- Si - [0039] Figure 6 also shows handles 70, 72 which facilitate carrying of the portable rack frost remover 10. The use of the rechargeable battery 66 means that the rack frost remover 10 can be moved and used conveniently in a variety of locations.

[0040] Referring to now to Figure 7, the cross sectional view shows the rack 12 as it is approaching the rack sprayer 42 on the rollers 34, 36. The rack sprayer 42 is activated in Figure 7 to spray de-icing fluid on the leading sidewall 64 of the rack 12, to expose the barcode shown on the leading sidewall 64. Figure 7 also shows a disposable bag 74 of de-icing fluid. The disposable bag 74 is hung on a hook 76 which is part of the structure for an NFC reader 78. The de-icing fluid in the bag 74 is gravity fed through tubing 84 to the pumps 40, 44 for the sprayers 38, 42. The disposable bag 74 maintains the de-icing fluid in a sealed environment to prevent evaporation. The preferred de-icing fluid comprises 94.6% by volume of the 99% pure isopropyl, 5% by volume propylene glycol, and 0.4% by volume fragrance. When the de-icing fluid is applied to the bottom of the rack 12, to the bottom of the tubes within the rack 12, and optionally the leading wall 64 of the rack 12, frost coming in contact with the de-icing fluid melts and is removed immediately on contact. The isopropyl in the mixture quickly evaporates leaving a relatively thin film of propylene glycol. It has been found that the relative thin coating of propylene glycol inhibits frost reformation when the rack 12 is replaced into an ultra- low temperature (-80°C) or cryogenic freezer. It has also been found that using too much propylene glycol in the mixture is not desirable because it can result in sticking when the rack is replaced into the freezer environment. On the other hand, using less propylene glycol in the mixture will not result in sticking, but reduces the ability of the mixture to inhibit frost reformation.

[0041] The disposable bag includes an NFC chip 80 that includes identification data for the bag 74. The bag 74 hangs on the hook 76 so that the NFC chip 80 can be read by the NFC reader 78. The NFC reader 78 provides the information to the system controller 82, which in turn calculates and displays on the touch screen 22 the level of de-icing fluid remaining, or the number of racks that can be processed until the bag 74 needs to be replaced. The bag 74 has a feed tube 84 which connects to the inlets for the pumps 40, 44 for the sprayers 38, 42, or tubing leading to those inlets. Sealed connector such as a Luer fitting can be used for this purpose. An RFID chip and an RFID reader can also be used to implement this aspect of the invention.

[0042] Referring now in particular to Figures 8 through 10, in the disclosed embodiment, the DC stepper motor 50 drives the rollers in each row 34, 36 and also the rotating brush 14. The output shaft 86 from the motor 50 is connected to a belt drive axel 52 which includes a pulley 88 on each end to drive a respective drive belt 54, 56, see Fig. 4. Figures 8 through 10 show the details and operation of the belt drive for belt 54 which drives the first row of rollers 34 and the rotating brush 14 on the side adjacent the first row of rollers 34. It should be understood that the structure and operation of the belt drive for belt 56 that drives the second row of rollers 36, and the rotating brush 14 on the side adjacent the second roll of rollers 36 has the same configuration. The drive axel 52 transmits power to the belt drive for the belt 56 that drives the second row of rollers 36 and the side of the brush adjacent the second row 36 of rollers.

[0043] The drive belt 54 has teeth on its inside surface. Each roller 34 is coaxially mounted with the cylindrical gear 90 that intermeshes with the teeth on the drive belt 54. The gear 90 and the roller 36 are fixed together so that they rotate in unison. The belt 54 is driven by the drive pulley 88, which could also be a drive gear. As shown in Figure 9, the drive belt 54 is pulled by the motor 50 through the rotation of the drive pulley 88 in the counter clockwise direction in accordance with the arrows. The drive belt 54 rides over the top of the gears 90 and is threaded underneath idler wheels 92. As shown in more detail in Figure 10, the idler wheels 92 push downward on the drive belt 54 so that its teeth maintain contact with the gears 90 for the respective rollers 34.

[0044] Referring now in particular to Figure 9, as the belt 54 passes over the gears 90 for rollers 34, it turns the roller 34 to move the rack 12 to the left in Fig. 9. On the other hand, as the belt rotates underneath the gears 90 and the rollers 34, the belt 54 drives the rotating brush 14 to rotate in Figure 9 in a clockwise direction which is opposite to the direction that the rollers 34 are moving the rack. To do this, each side of the brush 14 has a central driven gear 94 along its central axel 46. The central driven gear 94 is driven by an intermediate, offset gear complex 96 that is mounted to the mounting bracket 48 attached to the frame 30. The offset gear complex 96 includes two gears that are fixed to a rotatable shaft that is mounted to the bracket 48. In Fig. 9, the gear with the smaller diameter of the complex 96 is driven by the drive belt 54. Idler wheels 98 are also mounted to the bracket 48, and hold the teeth of the belt 54 in contact with the teeth on the smaller gear of the gear complex 96. The larger gear in the gear complex 96 is offset horizontally and meshes with the central driven gear 94 for the brush 14. The belt 54 drives the offset gear complex 96 in the counter-clockwise direction as shown in Figure 9, which in turn drives the central gear 94 and the rotating brush in the clockwise direction in Figure 9. The size of the gears is chosen so that the brush will rotate 14 at appropriate speeds. In the disclosed embodiment, the maximum speed of rotation is 200 rpm for the brush 14, while the maximum speed of rotation for the roller 34, 36 is 60 rpm.

[0045] Referring again to Figures 5 and 6, reference number 66 depicts an optional camera used to scan the 2D barcodes on the bottom of storage tubes in the racks 12 immediately after they have been wiped by the wetted rotated brush 14. If the camera 62 is not provided, the rack 12 can be removed from the output station 18 and placed on a scanner, or a handheld scanner can be used. Although not shown in the drawings, a dryer brush downstream of the rotating wetted brush 14 can be used to wipe the bottom of the racks and the tubes as well.

[0046] The above described embodiment is configured to be portable and process single racks in series; however, it is contemplated that the system can be configured to process multiple racks in parallel for particularly large jobs.

[0047] While the above described embodiment is configured to it SB S -formatted tube storage racks, it is possible to configure the system to accommodate racks or cryo-box having different dimensions.

Claims

CLAIMS What is claimed is:

1. A frost remover for removing frost from tube storage racks, and from tubes stored in the racks, the system comprising: a rotating brush mounted along a horizontal axis of rotation; a motor that drives the rotating brush; a brush sprayer that sprays de-icing fluid on a lower portion of the rotating brush; and means for conveying at least one tube storage rack along a path over the rotating brush with a bottom of the tube storage rack exposed underneath the path; wherein the lower portion of the rotating brush is wetted with de-icing fluid from the brush sprayer and the upper portion of the rotating brush applies the de-icing fluid to the bottom of the rack and to the bottoms of storage tubes held in the rack as the rack is conveyed along the path over the brush.

2. The frost remover in claim 1 wherein said means for conveying comprises a first row of rollers and a second row of rollers spaced apart and driven in unison, wherein conveyed racks straddle the first and second row of rollers.

3. The frost remover in claim 1 further comprising a first longitudinal guide rail located above the first row of rollers and a second longitudinal guide rail located above the second row of rollers, said first and second longitudinal guide rails being parallel to each other and spaced apart to guide an SBS-formatted tube storage rack along the path over the rotating brush while being conveyed by the first and second rows of rollers.

4. The frost remover in claim 2 wherein the first row of rollers includes a first gap and the second row of rollers includes the second gap, wherein the upper portion of the rotating brush engages the bottom of the conveyed rack when rack is located over the first and second gaps.

5. The frost remover according to any of the preceding claims wherein the width of the brush is sufficient to reach the entire width of the bottom of a conveyed SBS-formatted rack.

6. The frost remover according to any of the preceding claims wherein brush thin, pliable bristles and rotates up to 200 rpm.

7. The frost remover according to any of the preceding claims further comprising an input station and an output station, and the means for conveying moves the rack from the input station to the output station, wherein the rack is preferably conveyed from the input station to the output station in 15 seconds or less.

8. The frost remover according to any of the preceding claims further comprising a rack sprayer that sprays de-icing fluid over a leading sidewall of a storage rack being conveyed through the frost remover.

9. The frost remover according to any of the preceding claims wherein the de-icing fluid is a mixture comprising isopropyl and propylene glycol, and the mixture preferably comprises essentially 94.6% isopropyl, 5% propylene glycol and .4% fragrance.

10. The frost remover according to any of the preceding claims further comprising: a proximity sensor to determine the presence of a tube storage rack in the output station; and/or a barcode scanner on the path between the rotating brush and the output station; and/or a housing having a cover over the path between the input station and the output station; and a catch basin located underneath the rotating brush; and/or a power source that includes a rechargeable battery and is configured to provide DC power to operate the frost remover, the DC power being derived from line power when line power is available and from battery power when line power is not available.

11. The frost remover according to any of the preceding claims wherein the de-icing fluid is contained in a gravity fed disposable container that is gravity fed to a pump for the brush sprayer.

12. The frost remover according to claim 11 wherein the de-icing fluid contained in a gravity fed disposable container is also gravity fed to a pump for a rack sprayer.

13. The frost remover according to claim 11 further comprising an RFID or NFC reader; wherein the disposable container contains an NFC or RFID chip with data that identifies the disposable container.

14. A disposable container of de-icing fluid for use in a rack frost remover, the container comprising: a bag containing a mixture comprising isopropyl and propylene glycol, said glycol comprising no more than 5% (volume) of the mixture, said bag preventing the mixture from evaporating; a feed tube that is connected to the bag and is adapted to be connected to one or more pump inlet for a rack frost remover; and means for attaching the bag to the rack frost remover so that the mixture is gravity fed from the bag through the feed tube for use by the one or more pumps.

15. The disposable container in claim 14 further comprising an RFID or NFC chip that contains information to identify the disposable container.