Apparatus for irradiating goods loaded in shipping boxes

Abstract

The present invention relates to an apparatus for irradiating cargo with radiation (11x) selected from X-rays or electron beams, the apparatus comprising: a radiation (11x) source (11) configured to emit radiation (11x) along an irradiation volume (Xv) centered on an irradiation axis (X); a conveyor (3) configured to drive cargo loaded in two or more transport units (1.i) having a unit height (h1i) through the irradiation volume so as to expose a first portion of the cargo to radiation, the unit height being measured along a longitudinal axis (Z), wherein the transport units (1.i) are loaded in transport containers (5) having a transport container height, and wherein the conveyor (3) is configured to drive N transport units (1.i) loaded with cargo. i) a shipping container (5) such that the shipping container (5) accommodates N transport units, wherein N≥1, the transport units are arranged vertically to extend the total height (ht), and wherein each transport unit (1.i) is held in place in the shipping container (5) by one or more support elements (5s) such that the total height (ht) is between 40% and 100% of the height of the shipping container (h5) (i.e., 40%h5≤ht≤h5), the N transport units (1.1-1.N) loaded in the shipping container span at least 70%, preferably at least 80% of the total height (ht) (i.e., ), the total height (ht) is centered relative to the height of the shipping container (h5) with an error within ±20% (i.e., (Ht1-1 / 2ht)=1 / 2h5±20%).

Description

Technical Field

[0001] This invention relates to an apparatus for irradiating cargo with radiation selected from X-rays or electron beams, which ensures enhanced throughput while simultaneously ensuring enhanced radiation uniformity and energy efficiency compared to current state-of-the-art equipment. This is made possible by loading the cargo into a shipping container according to certain constraints on positioning and distributing the cargo along the longitudinal axis (Z) within the container. The shipping container carrying the cargo is driven through the irradiation volume by a conveyor. Background Technology

[0002] Irradiation of goods with X-rays or electron beams has been used for various purposes, including sterilization, crosslinking of resins and paints, shrink-fit polymer sheets or tubes (e.g., sheaths around cables), and so on. X-ray or electron beam sterilization of medical devices, tools, and clothing, as well as food sterilization, has been reported in this field. X-ray sterilization is superior to other types of sterilization techniques (e.g., gamma irradiation or ethylene oxide sterilization) because X-rays can penetrate densities up to 1.0 g / cm³. 3 The trays and containers are filled to capacity, which is superior to the aforementioned technologies. X-ray sterilization is highly tolerant of density changes.

[0003] X-rays are a type of high-energy electromagnetic radiation. Most X-rays have wavelengths ranging from 10 pm to 10 nm, which corresponds to approximately 3 × 10⁻⁶ ppm. 16 Hz to 3×10 19 The frequency range is Hz. A common practice is to distinguish between X-rays and gamma rays based on the radiation source: X-rays are emitted by the interaction of accelerated electrons with a target (preferably a high-Z metal), while gamma rays are emitted by atomic nuclei (e.g., cobalt-60). The photon energies emitted by cobalt-60 are measured at 1.17 MeV and 1.33 MeV. These high-energy photons are emitted in all directions or in an isotropic manner. The energy of X-rays is directly related to the electron energy. X-rays are produced by the interaction of accelerated (high-energy) electrons with atoms in the target material. When the high-energy electron passes near the atomic nucleus, all or part of the electron's energy is separated from the nucleus and propagates in space as electromagnetic radiation (=X-rays). The heavier the element (i.e., the higher the atomic number or 'Z value'), the higher the X-ray conversion efficiency. Metals (e.g., tantalum (Ta) or tungsten (W)) are typically used as target materials. The resulting X-ray energy spectrum ranges from zero to the maximum energy of the incident electron. The design of the converter plays a crucial role in the characteristics of the X-rays. The converter material (Z-value) and its thickness determine the yield and fine-tuning of the energy spectrum, respectively. Typically, industrial accelerators suitable for this invention are designed to produce electron energies up to 10 MeV, typically using 5 MeV to 7 MeV electrons to generate X-rays.

[0004] The electron energy used to generate X-rays or for the direct use of electron beams can be increased by accelerating the electrons in an accelerator. The following accelerators are available on the market: • L-band linear accelerator (accelerates RF in the 1 GHz range; multiple cavities in a single pass; e.g., Impela) DC accelerator (direct current; e.g., Dynamitron) • Rhodotron (RF accelerator; multiple passes through a single cavity, e.g., TT200)

[0005] When the incident electron beam is <100 keV to generate X-rays, the resulting photons are emitted equally in all directions. As the energy of the incident radiation increases, the bremsstrahlung beam becomes more "forward-peaked". To control the geometry of the irradiation volume emitted from the converter (or target), a scanning horn (11h) in the shape of an inverted funnel is used. The shape and size of the scanning horn determine the geometry and size of the irradiation volume (Vx) generated by the X-ray source with the specific scanning horn.

[0006] Bulk shipments awaiting X-ray or electron beam irradiation may be stacked on pallets or enclosed in containers. Containers may be self-supporting or may be placed on top of pallets. Such bulk shipments and pallets and / or containers are collectively referred to as “transport units.” As shown in Figures 1(a) and 1(b), in front of a radiation source (11) selected from X-rays and electron beams, transport units are typically transported in prior art systems on conveyors that drive them horizontally along the transverse axis (Y). In the case of such systems, the dose deposition distribution on the shipment decreases rapidly by absorption along the irradiation axis (X), with the irradiated volume centered on this irradiation axis, as is known in the art.

[0007] One way to quantify the variation in dose deposition distribution along a given direction or plane is to calculate the dose uniformity ratio (DURi) along said direction or plane, where DURi = DMi / Dmi, where DMi is the maximum dose deposited along said direction and Dmi is the minimum dose, i = X, Y, or Z. The value of DURi defines a perfectly uniform dose deposition distribution along a given direction i. The larger the value of DURi, the greater the variation in dose deposition along direction i.

[0008] To date, two main alternative technologies are used: single-layer and double-layer irradiation systems. In the single-layer irradiation system shown in Figure 1(a), the cargo is aligned on a single conveyor in only one horizontal plane and irradiated by overscanning, i.e., using a scanning horn to generate an irradiation volume along the longitudinal axis (Z) with a height (h1i) greater than that of the transport unit (1i). The advantage of the single-layer system is that only a single pass is needed to irradiate the first portion of the cargo (the remaining portions can be irradiated by rotating the cargo and exposing new portions to radiation, as explained further). However, a larger scanning horn is required, which correspondingly increases installation costs.

[0009] A two-layer system is illustrated in Figure 1(b) and described in EP 1738776. It requires two superimposed conveyor tracks arranged vertically to transport goods on two horizontal planes. The radiation approximation is centered on the mid-horizontal plane of the total height (ht) of the two superimposed transport units, driven by the bottom and top tracks respectively, and arranged in an under-scan configuration, i.e., using a scanning horn to generate an irradiation volume with a scan width (hx) below the total height (ht) of the transport unit as measured along the longitudinal axis (Z). After the transport units are inverted between the top and bottom conveyors, they are passed a second time (after being irradiated for the first time while being transported on the top or bottom conveyor) for further irradiation. The fact that the transport units must pass twice in an irradiation volume compared to a single-layer system would intuitively suggest a 50% reduction in throughput. However, this is not the case because in a two-layer system, both transport units are irradiated simultaneously in each pass. Furthermore, the DUR of the two-layer system is reduced (i.e., enhanced) compared to a single-layer system. The choice between using a single-layer or double-layer system remains the operator's decision and choice, depending on the available equipment, the type of goods to be processed, the type of process targeted by the irradiation (sterilization, polymerization, etc.), and so on.

[0010] Because the conveyors (multiple) drive the cargo through the irradiation volume (Vx) at a controlled speed along the transverse axis (Y), the dose deposition distribution along the transverse axis (Y) of the conveyors is essentially constant, with DURy close to 1. The dose deposition distribution along the irradiation axis (X) (i.e., parallel to the irradiation axis) decreases with penetration depth, resulting in a high DURx value, as shown by the dashed line in Figure 7(b). The value of DURx can be reduced by rotating the cargo about the longitudinal axis and, as needed, driving it through the irradiation volume to expose different parts of the cargo to radiation. The solid line in Figure 7(b) shows the dose deposited along the irradiation axis (X) after two passes through the irradiation volume (by rotating the transport unit 180° to expose two opposite parts of the transport unit) (= the sum of the two dashed lines). Alternatively, a second radiation source (not shown) can be provided, pointing towards the surface of the transport unit opposite the surface irradiated by the first radiation source. The advantage of the latter solution is increased throughput, but purchasing a second radiation source correspondingly increases installation costs.

[0011] However, the dose deposition distribution along the longitudinal axis (Z) varies significantly because the height of the transport unit containing the cargo can vary considerably from one transport unit to another. Since high-energy X-rays propagate in a forward peak mode, a higher X-ray dose is deposited into the cargo at the horizontal plane of the irradiation axis (X), and the X-ray dose deposited along the longitudinal axis (Z) decreases with increasing distance from the irradiation axis (X). Therefore, variations in the height of the target unit produce a large corresponding variation in the dose deposition distribution along the longitudinal axis (Z), thus increasing the corresponding DURz >> 1 value along the longitudinal axis (Z). The bilayer system mitigates this dose deposition variation along the longitudinal axis (Z), but at the cost of significant energy waste. Uniform dose deposition (i.e., DUR → 1) is important in many applications because the entire cargo volume must receive a minimum dose sufficient to achieve the objectives of the irradiation process (e.g., sterilization, crosslinking, etc.). This means that the minimum dose (Dmz) deposited on the cargo must be at least equal to a sufficient dose. If DURz = DMz / Dmz is >> 1, the maximum dose (DMz) deposited in some parts of the cargo may be too high for the integrity of the cargo, and said parts of the cargo may degrade due to excessive irradiation. Therefore, it is important to reduce DURz and thus ensure that DUR is sufficiently close to 1 in all directions, for example, DUR < 1.4.

[0012] To minimize the DURz value in the vertical direction in the single-layer system depicted in Fig. 1(a), the scanning horn (11h) must be sized to overscan beyond the boundaries of the target product so as to deposit the dose according to the relatively flat bottom segment of the dose deposition curve having an approximately parabolic shape about the longitudinal axis (Z). To limit the size and cost of the X-ray scanning horn, the overscan is typically limited to 20 cm to 30 cm beyond the boundaries of the transport unit. However, since the unit height (h1i) of the transport unit can vary significantly from one transport unit to another, it is not possible to optimize DURz with a single scanning horn that fits all heights at a reasonable cost. Note that changing the scanning horn between two target products is both cumbersome and impractical.

[0013] The dual-layer system shown in Fig. 1(b), Fig. 5(e) and Fig. 5(f) produces a lower (better) DURz value by driving the goods through the irradiation volume twice in swapped positions along the longitudinal axis (Z). Thus, although the DURz of the transport units in both the bottom and top conveyors is quite high after the first pass, by swapping their positions in the second pass, the variation in dose deposition is reversed and the variation accumulated during the first pass is compensated. However, the top and bottom conveyors are in fixed positions that are separated from each other by a fixed conveyor separation distance (h3) that cannot be modified. The conveyor separation distance (h3) has two main drawbacks. First, it defines an upper bound (h1i < h3) for the unit height (h1i) of the transport units that can be driven by the bottom conveyor. Second, for transport units with a height (h1i) much lower than h3 (i.e., h1i << h3), as shown in Fig. 5(g), there is a large gap between the top conveyor and the top of the transport unit driven by the bottom conveyor, where the X-rays or electron beam are lost at this gap and must be contained in this gap, resulting in a significant amount of energy waste. This can be quantified by the exposure ratio, which is defined as the ratio of the sum of the unit heights (h11, h12) of the transport units (1.1, 1.2) carried by the bottom and top conveyor tracks to the total height (ht). The larger the exposure ratio, the larger the portion of the radiation that hits the transport unit.

[0014] To reduce (improve) DURz, US 6504898 discloses a rotating system in which the product rotates in front of the radiation source. When the X-ray radiation is scanned up and down, the tray slowly rotates about its longitudinal axis. A shutter device consisting of a pair of X-ray absorbing gates is located between the X-ray conversion plate of the scanning horn and the tray to shape the X-ray pattern and attenuate the X-ray intensity during the rotation of the tray's face towards the scanning horn.

[0015] A drawback of this X-ray irradiation system is that the louvers cause valuable X-ray energy to be converted into heat and wasted. A further drawback is the reliance on the precise mechanical movement and rotation of the irradiated target to achieve the desired dose uniformity. The timing and control of the louvers must be mechanically synchronized with the rotation of the tray on the turntable to compensate for variations in material thickness.

[0016] US 6940944 describes an apparatus for irradiating a target product, the apparatus comprising a radiation source, a collimator having a variable orifice, and a turntable. The collimator is adapted to adjust its orifice prior to irradiating the package.

[0017] Alternative irradiation methods have been developed to irradiate a wide variety of products with different densities, and these irradiation methods have improved DUR (Difference of Intake). EP 1459770, cited previously, discloses a process in which at least two trays are mounted on a rotating device for simultaneous irradiation. EP 1738776, discussed previously, discloses a dual-layer X-ray irradiation system in which trays are arranged on two stacked horizontal planes and an X-ray beam is guided along a height corresponding to a distance from the midpoint of the lower horizontal plane to the midpoint of the upper horizontal plane of the tray assembly. The horizontal planes of the trays are then switched for complete irradiation.

[0018] Existing solutions are designed for transport units with a specific shape or all having substantially the same height (h1i). If such a system is required to handle transport units with varying heights, the beam scan width needs to be adapted to the product height to avoid processing inefficiencies. This leads to complex scheduling strategies.

[0019] This invention provides a simple and easy-to-implement solution for reducing the displacement ur (DUR) of goods contained in transport units of varying shapes and sizes irradiated by X-rays or electron beams in all directions, particularly along the longitudinal axis (Z). These and other advantages of the invention will continue to be presented. Summary of the Invention

[0020] The invention is defined in the appended independent claims. Preferred embodiments are defined in the dependent claims. In particular, the invention relates to an apparatus for irradiating cargo with radiation selected from X-rays or electron beams, the apparatus comprising: • A radiation source selected from X-rays and electron beams, configured to emit radiation (11x) along an irradiation volume (Xv) centered on the irradiation axis (X). • A conveyor (3) is configured to drive goods loaded in two or more transport units (1.i) having a unit height (h1i) through an irradiated volume along a transverse axis (Y) perpendicular to both the irradiation axis (X) and the longitudinal axis (Z), so that a first portion of the goods is exposed to radiation, the unit height being measured along the longitudinal axis (Z) perpendicular to the irradiation axis (X).

[0021] The transport units are loaded in a transport container with a height (h5 = H51 - h50), which is measured along the longitudinal axis (Z) from the bottom at the bottom height (h50) to the top at the top height (h51), and the conveyor is configured to drive the transport container (5) carrying N transport units loaded with goods, wherein • The shipping container includes support elements for supporting the transport unit, wherein these support elements can be positioned at different levels along the shipping container height (h5). • The shipping container can hold N transport units, of which And N≥1, these transport units are arranged vertically to extend the total height (ht=Ht1-Ht0), which is measured along the longitudinal axis (Z) from the bottom of the first transport unit positioned closest to the bottom unit height (Ht0) of the container to the top of the Nth transport unit positioned closest to the top unit height (Ht1) of the container.

[0022] Each transport unit is held in place in the shipping container by one or more support elements, so that The total height (ht) includes 40% to 100% of the shipping container height (h5) (i.e., 40%h5≤ht≤h5), preferably between 60% and 80% of the shipping container height (h5). The N transport units loaded in the shipping container span at least 70%, preferably at least 80%, of the total height (ht) (i.e., ), The total height (ht) is centered relative to the height (h5) of the shipping container, with an error within ±20% (i.e., (Ht1-1 / 2ht)=1 / 2h5±20%), preferably within ±10% (i.e., (Ht1-1 / 2ht)=1 / 2h5±10%).

[0023] In a preferred embodiment, the device includes a processing control unit (PCS) configured to perform one or more of the following actions: • Measure the unit height (h1.i) of the transport unit before loading it into the shipping container. • Weigh the transport units and determine their corresponding densities. • Determine the target total height (ht0) based on the irradiated volume height measured along the longitudinal axis (Z), and select N transport units to load into each shipping container to achieve the total height (ht), which is lower than the shipping container height (h5) and included within ±10% of the target total height: (i.e., ht = ht0 ± 10%) <h5), • For each shipping container, optimize the height of the irradiated volume to accommodate the total height (ht) of the transport unit (1.i) loaded into the corresponding shipping container. • Determine the loading plan for the transport units, which specifies which transport units will be loaded into which shipping containers, and preferably assigns the loading position of each transport unit in the shipping container along the longitudinal axis. Based on the measured unit height (h1.i) of the transport unit, in order to maximize the fill ratio (ht / h5) of the total height (ht) to the container height (h5), and / or Based on the density thus determined, the N transport units loaded in the shipping container have similar densities, with an error within ±25%. • Assign each support element a position optimized based on the unit height of the transport unit to ensure the total clearance separating every two adjacent transport units in the same shipping container. Gap ratio to total height (ht) minimize.

[0024] In this embodiment, preferably, the device includes a loading station configured to load transport units onto shipping containers according to a loading scheme and, more preferably, according to the loading location. The loading station may be configured to position support elements at locations optimized based on the unit height of the transport unit to achieve a clearance ratio. Minimize. Transport units of similar density are preferably loaded into one or a series of transport containers. The conveyor can be configured to drive the one or series of transport containers through the irradiated volume at a speed that depends on the average density of the transport units loaded in the one or series of transport containers.

[0025] The device may include a rotating element configured to rotate the shipping container by a certain rotation angle (θ), and wherein the conveyor is configured to drive the shipping container several times through the irradiation volume so that each time the shipping container rotates by the rotation angle, second, third, and other portions of the cargo are exposed to radiation.

[0026] The device can be configured to perform single-layer irradiation of a shipping container using a scanning horn configured for overscanning, such that the irradiation volume includes the entire height of the shipping container (h5), and the first portion of the cargo of all N transport units loaded in the shipping container is exposed to the required dose in a single pass. Alternatively, the device can be configured to perform double-layer irradiation of the shipping container using a scanning horn configured for underscanning, such that the irradiation volume does not include the entire height of the shipping container (h5), and the first portion of the cargo of the N transport units loaded in the shipping container is exposed to the required dose in two passes. For the first pass, the first selection is to load the transport unit in the upper half of the shipping container (i.e., above 1 / 2 h5), and the second selection is to load the transport unit in the lower half of the shipping container (i.e., below 1 / 2 h5). For the second pass, the first choice is the transport unit loaded in the lower half of the shipping container, and the second choice is the transport unit loaded in the upper half of the shipping container.

[0027] If the device is configured for double-layer irradiation, it is preferred that it includes a switching unit configured to: transfer transport units (1.i) loaded in the upper half of the first transport container to the lower half of the second transport container (5), and transfer transport units loaded in the lower half of the first transport container to the upper half of the second transport container; and drive the second transport container through the irradiation volume.

[0028] The conveyor can be in the form of an overhead track, on which the shipping container (5) is suspended and driven. Alternatively, it can be in the form of a roller conveyor, on which the shipping container (5) is erected and driven.

[0029] The height (h5) of the shipping container can be between 500 cm and 650 cm, preferably between 550 cm and 600 cm. These dimensions are preferred for double-layer systems. For single-layer systems, the height (h5) of the shipping container is preferably, but not necessarily, lower, such as 290 cm to 350 cm, preferably 300 cm to 330 cm. The unit height (h1i) of the transport unit can be between 50 cm and 380 cm, preferably between 100 cm and 280 cm. The gap (hvi) separating two adjacent transport units in the same shipping container can be between 8 cm and 30 cm, preferably between 15 cm and 25 cm.

[0030] For the device according to the invention, the possible dose uniformity ratio (DURx) is no more than 1.4, preferably no more than 1.3, and more preferably no more than 1.15, to achieve 0.1 g / cm³. 3The uniform density, dose uniformity ratio is defined as the ratio (DMx / Dmx) of the maximum dose (DMx) to the minimum dose (Dmx) deposited into the cargo along the irradiation axis (X) between the bottom and top of the transport unit along the longitudinal axis (Z).

[0031] The present invention also relates to a method for irradiating goods loaded in a transport unit with radiation selected from X-rays and electron beams, the method comprising the following steps: • Provide the device as defined above. • Load the transport units into shipping containers equipped with support elements that support the transport units as defined above. • Drive the shipping container along the horizontal axis (Y) through the irradiated volume to expose the first part of the cargo. • The transport unit is irradiated with radiation as the shipping container is driven through the irradiated volume.

[0032] In a preferred embodiment, after passing through the irradiation volume once to expose a portion of the cargo, the shipping container is rotated by the rotation angle (θ) and driven back through the irradiation volume to expose different portions of the cargo contained in the transport unit.

[0033] If the conveyor is configured for double-layer irradiation of shipping containers and the equipment includes a switching unit, then the method includes: • Transfer the transport units loaded in the upper half of the first shipping container to the lower half of the second shipping container, and • Transfer the transport units loaded in the lower half of the first shipping container to the upper half of the second shipping container, and • Drive the second shipping container through the irradiation volume (Vx).

[0034] The method of the present invention has the advantage that the same scanning horn and irradiation axis (X) can remain constant throughout the process, regardless of the height (h1i) of the transport unit and the density of the cargo. Attached Figure Description

[0035] To more fully understand the nature of the present invention, reference is made to the following specific embodiments in conjunction with the accompanying drawings, in which: Figure 1(a): shows a perspective view of a single-layer irradiation system based on current technology. Figure 1(b): shows a perspective view of a two-layer irradiation system based on current technology. Figure 2(a): shows the various components that form the shipping container according to the invention. Figure 2(b): shows two transport units with different heights (h11 and h12). Figure 2(c): shows the shipping container of Figure 2(a), which has support elements in place and is loaded with the transport unit of Figure 2(b). Figure 3(a): shows a dual-layer system with various sizes at the current level of technology. Figure 3(b): A shipping container according to the invention, which has two transport units and is available in various sizes. Figure 4(a): A perspective view of a first embodiment of the irradiation system according to the present invention. Figure 4(b): A perspective view of a second embodiment of the irradiation system according to the present invention. Figures 5(a) and 5(b) illustrate two stages of double-layer irradiation of a transport unit loaded in a shipping container according to the invention. Figures 5(c) and 5(d) show two stages of double-layer irradiation of a transport unit loaded in a double-stacked track-type conveyor at the current technology level. Figures 5(e) and 5(f): show side views of two stages of the bilayer irradiation system according to the invention as illustrated in Figures 5(a) and 5(b). Figures 5(g) and 5(h): show side views of two stages of the bilayer irradiation system according to the current technology level, as illustrated in Figures 5(c) and 5(d). Figures 6(a) and 6(b): show a perspective view and a side view of a single layer of irradiation of a transport unit loaded in a shipping container according to the invention. Figure 7(a): shows the DURxz along the plane (X, Z) as a function of transport unit density for both single-layer (1-L) and double-layer (2-L) systems. Figure 7(b): Dose deposition along the irradiation axis (X) is plotted when only one part (dashed line, θ = 0 and θ = π) is exposed to radiation and when two opposite parts are exposed (solid line, M = 2). Figure 8(a): shows a side view of the dual-layer system according to the present invention. Figure 8(b): The minimum dose (Dmx) deposited along the irradiation axis (X) is plotted as a function of the cell height measured along the vertical axis (Z) according to the system in Figure 8(a). Figure 8(c): DURx along the irradiation axis (X) is plotted as a function of the cell height measured along the longitudinal axis (Z) according to the system in Figure 8(a). Figure 9(a): shows a side view of a two-layer system based on current technology levels. Figure 9(b): The minimum dose (Dmx) deposited along the irradiation axis (X) is plotted as a function of the cell height measured along the vertical axis (Z) according to the system in Figure 9(a). Figure 9(c): DURx along the irradiation axis (X) is plotted as a function of the cell height measured along the longitudinal axis (Z) according to the system in Figure 9(a). Figure 10(a): The minimum dose (Dmx) deposited along the irradiation axis (X) is plotted as a function of the density of the transport cells. Figure 10(b): DURx along the irradiation axis (X) is plotted as a function of the density of transport cells. Figures 11(a) and 11(b) illustrate two embodiments of the conveyor according to the present invention. Figures 12(a) to 12(f) The illustration shows the various stages of transferring a transport unit from a first shipping container to a second shipping container using a first embodiment of a swapping unit in a two-layer system. Figures 13(a) to 13(f) The illustration shows the various stages of transferring a transport unit from a first shipping container to a second shipping container using a second embodiment of a swapping unit in a two-layer system. Detailed Implementation

[0036] As shown in Figures 4(a) and 4(b), the present invention relates to an apparatus for irradiating cargo with radiation (11x) selected from X-rays or electron beams, the apparatus comprising a radiation (11x) source (11) configured to emit radiation (11x) along an irradiation volume (Xv) centered on an irradiation axis (X). Cargo is conveyed through the irradiation volume (Xv) supported on or enclosed in transport units (1.i), which may be pallets, containers, containers loaded on pallets, etc. A conveyor (3) is configured to drive cargo loaded in two or more transport units (1.i) having a unit height (h1i) substantially perpendicular to both the irradiation axis (X) and the longitudinal axis (Z) through the irradiation volume so that a first portion of the cargo is exposed to radiation, the unit height being measured along the longitudinal axis (Z) perpendicular to the irradiation axis (X).

[0037] The essence of the invention is to load one or more transport units (1.i) into a shipping container (5) and to configure a conveyor (3) for driving the shipping container (5) carrying N transport units (1.i) containing goods through an irradiated volume (Xv), where N ≥ 1. These shipping containers have a shipping container height (h5 = H51 - h50), which is measured along the longitudinal axis (Z) from the bottom at the bottom height (h50) to the top at the top height (h51). The shipping container (5) accommodates N transport units, wherein... And N≥1, these transport units are arranged vertically to extend the total height (ht=Ht1-Ht0), which is measured along the longitudinal axis (Z) from the bottom of the first transport unit (1.1) positioned at the bottom of the container (5) closest to the bottom unit height (Ht0) to the top of the Nth transport unit (1.N) positioned at the top of the container closest to the top unit height (Ht1).

[0038] Referring to Figure 3(b), according to the invention, each transport unit (1.i) is held in place in the shipping container (5) by one or more support elements (5s), such that The total height (ht) includes 40% to 100% of the shipping container height (h5) (i.e., 40%h5≤ht≤h5), preferably between 50% and 90% of the shipping container height (h5), and more preferably between 60% and 80%. o N transport units (1.1-1.N) loaded in a shipping container span at least 70% of the total height (ht) (i.e., ), preferably at least 80% (i.e., In other words, the exposure ratio is... Preferably ≥80%; this means that the total height of all gaps (hvi) measured along the longitudinal axis (Z) (separating the top of the first transport unit and the bottom of the adjacent second transport unit positioned above the first transport unit) does not exceed 30% of the total height (ht) (i.e., Preferably, it should not exceed 20% (i.e., ), The total height (ht) is centered relative to the height of the shipping container (h5), with an error within ±20% (i.e., (Ht1-1 / 2ht)=1 / 2h5±20%), preferably within ±10% (i.e., (Ht1-1 / 2ht)=1 / 2h5±10%); thus, for any transport unit (1.i) of any height (h1i), the irradiation axis (X) of the radiation source (11) can be centered at approximately the middle height of the shipping container.

[0039] Figure 3(a) shows a double-stacked track system according to the current level of technology, which can be advantageously replaced by the embodiment of Figure 3(b) of the present invention. Transport units and shipping containers

[0040] The goods to be irradiated can be any type of goods suitable for radiation treatment. For example, for sterilization processes, the goods can be food, pharmaceuticals, medical equipment, electronic components, clothing, etc. For polymerization, crosslinking, and shrinkage maturation, the goods can include polymers and polymer precursors. The goods can be stacked on pallets. The goods can be stored in containers made of a material that is substantially transparent to radiation. The goods can also be stored in containers standing upright on pallets. Pallets and containers that contain goods are collectively referred to as transport units (1.i), whether they are open structures or closed containers.

[0041] Referring to Figure 2(b), the transport unit has a basically standardized footprint of approximately 100 to 150 cm in the plane (X, Y). In Europe, many pallets are 100 x 120 cm. 2 The standard dimensions are as follows. However, the height (h1i) of the transport unit (1.i) along the longitudinal axis (Z) can vary significantly from one unit to another. For example, the unit height (h1i) of a transport unit can vary from tens of centimeters, such as 30 cm to up to 400 cm, or from 50 cm to 380 cm, preferably from 100 cm to 300 cm, and more preferably from 120 cm to 280 cm. The difference in unit height between two transport units is one of the reasons for the large variation in the DURx value, which is a function of the height observed between transport units with different unit heights processed using facilities with current process levels. Such dose deposition inhomogeneities between different transport units that have been similarly processed are undesirable and unacceptable for some applications.

[0042] The shipping container is a structure that includes support elements for holding N transport units one on top of the other. These support elements can be positioned at different levels along the height (h5) of the shipping container. The shipping container can be an open or closed structure. If the shipping container is a closed structure, the parts exposed to radiation must be made of a material that is substantially transparent to X-rays or electron beams. Figure 2(a) shows a shipping container in the form of a semi-open structure that has support elements in the form of shelves. It is clear that the support elements can have any shape and geometry as long as they are configured to hold the corresponding transport units in place at a given position along the longitudinal axis (Z). Instead of shelves as shown in Figure 2(a), the support elements can be in the form of discrete modules (such as pins), discrete modules that are configured for example to support the corners of a pallet each, or in the form of ledges or bars that extend along the irradiation axis (X) or across the transverse axis (Y) to support the edges of the transport units. The structure of the shipping container can be provided with apertures or grooves distributed at different heights along the longitudinal axis (Z) to accommodate the support elements as discussed previously. Figure 2(c) shows the shipping container of Figure 2(a) loaded with the two transport units of Figure 2(b). Since the support elements (5s) can be connected to the shipping container at different heights along the longitudinal axis (Z), it is possible to customize the position of the transport units according to any criterion. For example, reducing the clearance height (hvi) to reduce the overall height (ht), and increasing the exposure ratio This exposure ratio defines the proportion of the overall height (ht) filled by the goods. It is also possible to move the overall height (ht) of the transport units up and down along the longitudinal axis (Z) by changing the values of the distances (hd, hu) that separate respectively the bottom end and the top end of the shipping container from the adjacent transport units.

[0043] N is a natural number and can take any value as long as the overall height (ht) remains less than the height of the shipping container (h5), i.e., ht < h5. Figures 4(a) and 4(b) show a shipping container loaded with N transport units, where N = 1, 2, or 3. Higher values of N are possible where the shipping container carries 4, 5, or more transport units as long as the condition ht < h5 is satisfied.

[0044] The footprint of the shipping container on the plane (X, Y) is adapted to receive the transport units. As previously mentioned, the standard size of a pallet in Europe is 100 x 120 cm 2This means that the footprint of the shipping container should be slightly larger than that of the transport unit, approximately 110 to 120 cm for every 130 to 140 cm. The container height (h5) may differ for single-layer and double-layer systems. In a single-layer system, irradiation is performed in overscan mode, while in a double-layer system, irradiation is performed in underscan mode. Assuming the same scanning horn (11h) is used with a scan width (hx) measured along the longitudinal axis (Z) (e.g., 300 cm), the total height (ht) of the transport units stacked in the shipping container must be less than this scan width (hx) for a single-layer system and greater than this scan width (hx) for a double-layer system.

[0045] While the same shipping container height (h5) can be used for any value of the total height (ht), if the equipment is designed to operate only as a single-layer or double-layer system, the shipping container height (h5) can be optimized to match the scan width (hx) and the corresponding total height (ht) of the transport units (1.i) stacked in a shipping container. For example, assuming N = 2 transport units (1.1, 1.2) have unit heights h11 = 120 cm and h12 = 140 cm and the height gap between these two transport units is hv1 = 15 cm, then the resulting total height ht = 120 + 140 + 15 = 275 cm. A scanning horn with a scan width hx = 300 cm > ht would be suitable for a single-layer system. For a single-layer system, the shipping container height (h5) can be approximately 290 cm to 350 cm, preferably approximately 300 cm to 330 cm. This also applies to shipping containers (5) that contain a single transport unit (1.1) with a unit height of, for example, h11 = 270 cm.

[0046] In contrast, a shipping container height (h5) of approximately 500 cm to 650 cm, preferably approximately 550 cm to 620 cm, and more preferably approximately 580 cm to 610 cm is required to accommodate N = 2 transport units (1.1, 1.2) with heights h11 = h12 = 270 cm and a height gap of hv = 15 m, resulting in a total height of 2 x 270 + 15 = 555 cm. A shipping container carrying two transport units will be suitable for processing in a two-layer system using a scanning horn with a scanning width hx = 300 cm. The foregoing figures are purely illustrative to give the order of magnitude of the dimensions. They may vary within ±20% without departing from the preferred embodiments of the invention.

[0047] As shown for transport units #(1.j), (1.(j+1)), and (1.(j+2)) in Figures 4(a) and 4(b), the shipping container can carry more than one or two transport units (1.i), depending on the container height (h5), unit height (h1i), gap height (hv), and the resulting total height (ht), as well as the scan width (hx) and the type of single-layer or double-layer system applied to the transport units. The gap height (hvi) between two adjacent transport units loaded in the shipping container can include between 8 cm and 30 cm, preferably between 12 cm and 25 cm, and more preferably between 15 cm and 20 cm. N can be any natural number. In most applications, N can include between 1 and 6, preferably between 2 and 4.

[0048] The cargo contained in the volume of the transport unit (1.i) typically has a content of 0.05 g / cm³. 3 up to 0.5 g / cm 3 The density of the transport units is relevant because radiation absorption increases with density as it penetrates the cargo. For this reason, it is preferable that the transport units are categorized according to their density, and that N transport units loaded in a shipping container have similar densities. It is further preferred that several shipping containers in a batch are loaded with transport units of similar densities. In this way, such batches of shipping containers can be sequentially driven through the irradiated volume (Vx) at a constant speed. Optimization of loading from transport unit (1.i) to each shipping container (5)

[0049] In a preferred embodiment of the present invention, the device comprises a processing control unit (PCS) (7), which is configured to optimize the loading sequence of the transport units within a shipping container and above different shipping containers (5). The PCS (7) may include or be coupled to measuring equipment for measuring one or more parameters regarding the transport units, such as the unit height (h1.i), weight, and / or density of the transport unit (1.i). As shown in FIGS. 11(a) and 11(b), the measurements are carried out before loading the transport units into the shipping container (5). Then, the PCS may use these measured values to determine a target total height (ht0) based on the irradiated volume height measured along the longitudinal axis (Z) and select N transport units (1.i - 1.N) to be loaded in each shipping container (5) to achieve a total height (ht) that is lower than the shipping container height (h5) and within ±10% of the target total height: (i.e., ht = ht0 ± 10% < h5). In the case of using the same scanning horn, it is possible to vary the scanning width (hx) of the irradiated volume measured along the longitudinal axis (Z) within a certain range. The PCS (7) may be configured to adapt the scanning width (hx) of the irradiated volume according to the total height (ht) of the N transport units to further optimize the irradiation of each shipping container.

[0050] Preferably, the PCS (7) is configured to determine a loading plan for the transport units (1.i), which assigns which transport units (1.i) will be loaded in which shipping containers and preferably assigns the loading position of each transport unit (1.i) within the shipping container along the longitudinal axis. The loading positions of the shipping containers and the transport units can be assigned, · according to the thus measured unit height (h1.i) of the transport unit, so as to maximize the filling ratio (ht / h5) of the total height (ht) to the shipping container height (h5), and / or · according to the thus determined density, such that the N transport units (1.1 - 1.N) loaded in the shipping container have similar densities, with an error within ±25%.

[0051] The PCS (7) may also be configured to assign an optimized position to each support element (5s) according to the unit height of the transport unit (1.i) to minimize the exposure ratio, or in other words, to minimize the total gap separating every two adjacent transport units (1.i, 1.(i + 1)) within the same shipping container with respect to the gap ratio to the total height (ht).

[0052] As shown in Figures 11(a) and 11(b), the PCS (7) is preferably connected to the loading station (4). The loading station can be configured to position the support element (5s) at a location optimized, for example, based on the unit height of the transport unit (1.i), as discussed above, to achieve a clearance ratio. Minimize. The loading station (4) can also be configured to load transport units (1.i) onto transport containers (5) according to a loading scheme and preferably according to the loading position in each transport container. As shown in Figures 11(a) and 11(b), the robot can load the identified transport units (1.i) into the corresponding empty transport containers (5e) as optimized by PCS (7). Conveyor (3)

[0053] The conveyor (3) can be in the form of an overhead track, on which the shipping container (5) is suspended and driven, as shown in Figure 4(b). Alternatively, the conveyor (3) can be a roller conveyor, on which the shipping container (5) is erected and driven, as shown in Figure 4(a). For stability reasons, an overhead track is preferred for transporting shipping containers with a large container height (h5) typically used in double-layer systems, which require a container height of approximately 500 cm to 620 cm. For lower container heights typically used in single-layer systems, either a roller conveyor or an overhead track can be used.

[0054] Examples of conveyor designs are shown in Figures 11(a) and 11(b). The conveyor may include sections for individually conveying transport units (1.i) in front of the PCS (7) for measuring height, weight, and / or density. A loading station (4) is connected to the PCS (7) and loads the individual transport units into their corresponding shipping containers at defined locations along the longitudinal axis (Z) as determined and optimized by the PCS (7). Empty shipping containers (5e) are parked within reach of the loading station (4), awaiting loading of each shipping container with N transport units. The conveyor (3) is driven in front of the radiation source (11) at a predefined speed, driving the thus loaded shipping containers through the irradiation volume (Vx).

[0055] In a preferred embodiment, transport units (1.i) of similar density are loaded into one or a series of transport containers (5) via a loading station (4), and a conveyor is configured to drive the one or series of transport containers through the irradiation volume at a speed that depends on the average density of the transport units (1.i) loaded in the one or series of transport containers.

[0056] Preferably, the conveyor (3) is equipped with a rotating element (3r) configured to rotate the shipping container (5) by a certain rotation angle (θ). The conveyor (3) is configured to drive the shipping container through the irradiation volume several times, so that each time the shipping container rotates by that rotation angle, a second, third, etc. portion of the cargo is exposed to radiation. In a simple but preferred embodiment, θ = 180°, and the conveyor (3) drives the shipping container a second time to expose the portion opposite to the portion first exposed to radiation before the emptied shipping container (5x). Alternatively, the rotating element (3r) may be located within the irradiation volume (Vx) to rotate the shipping container while it is being irradiated.

[0057] The same structure can be used to transport shipping containers in both single-layer and double-layer systems. The only difference lies in the scan ratio (hx / ht) between the scan width (hx) and the total height (ht) of the scanning horn. A scan ratio hx / ht > 1 defines an overscan mode suitable for single-layer systems, while a scan ratio hx / ht < 1 defines an underscan mode suitable for double-layer systems.

[0058] As shown in Figure 11(b), the double-layer system also requires a switching unit (9) configured to: transfer transport units (1.i) loaded in the upper half of the first transport container (5) to the lower half of the second transport container (5), and transfer transport units (1.i) loaded in the lower half of the first transport container (5) to the upper half of the second transport container (5); and drive the second transport container through the irradiation volume.

[0059] In a two-tiered system, PCS (7) can also be configured to optimize the number and sequence of second shipping containers, and the position of the support elements of an empty second shipping container (5e) awaiting receipt of transport unit (1.ix) from the first shipping container (5x) after the first exposure to radiation. The empty second shipping container is parked opposite the first shipping container (5x), and has support elements (5s) at corresponding positions for vertical or vertical swapping of transport units. Figures 12(a) to 12(f) As shown, the swapping unit (9) can be in the form of an elevator, configured to: retrieve the first transport unit from the first shipping container (5x) (see Figure 12(a)), transport the first transport unit along the longitudinal axis (Z) to its assigned new position in the second shipping container (see Figure 12(b)), and then load the transport unit into the second shipping container at its predefined, defined position (see Figure 12(c)). The same operation is repeated for each transport unit remaining in the first shipping container (see Figure 12(a)). Figures 12(d) to 12(f) ).

[0060] exist Figures 13(a) to 13(f)In another embodiment shown, the swapping unit includes two rotating arms, each equipped with a processing device for retrieving transport units from a shipping container, accommodating transport units, and loading transport units into the shipping container. The position of the processing device along the respective arm can vary. As shown in Figure 13(a), the two arms are initially held vertically, and the processing device is leveled with the corresponding transport unit for swapping. The two processing devices retrieve the two transport units (see Figure 13(b)), and the two arms rotate 180° about their central axis so that the transport units face their respective newly assigned positions in the second shipping container (see Figures 13(c) and 13(d)). If necessary, the position of the processing device carrying the two transport units can be changed to face the corresponding new positions in the second shipping container. The processing devices can then load their respective transport units into the second shipping container at their newly assigned positions (see Figures 13(e) and 13(f)).

[0061] These operations are repeated for each transport unit loaded into the first transport container so that all first transport containers have received the first layer of irradiation. The loaded second transport containers are then ready to drive the transport units through the irradiation volume (Vx) to receive the second layer of irradiation in the bilayer system. Empty first transport containers can be emptied and replenished, and then reloaded with a new set of N transport units. As explained previously, the number and position of the support elements can be adapted to the new loading of transport units. Single-layer system

[0062] As explained previously and shown in Figures 6(a) and 6(b), the single-layer system irradiates the transport units in an overscan mode, where the scan width (hx) is greater than the total height (ht) of the transport unit (1.i) (i.e., hx / ht>1). The cost of the scanning horn (11) increases superlinearly with the scan width (hx) it provides. Therefore, there is a financial incentive to keep the scan width (hx) within a reasonable size to limit installation costs. Thus, a single-layer system is generally preferred for transport units stacked in a shipping container with a total height (ht) of approximately no more than 300 cm (i.e., ht<300 cm). For example, assuming the scanning horn has a scan width hx = 300 cm and allows an overscan of approximately 15 cm both below and above the transport unit (1.i), the shipping container (5) can carry N transport units with a total height of approximately 270 cm.

[0063] Single-layer systems are simpler to operate and significantly faster than double-layer systems. In fact, the process throughput of single-layer and double-layer systems is not significantly different, for the following reasons. Although transport units loaded into a shipping container in a double-layer system must pass through the irradiation volume (Vx) a second time, the total height (ht) of transport units driven through the irradiation volume (Vx) in one pass in a double-layer system can be approximately twice the total height (ht) in a single-layer system.

[0064] Figure 7(a) compares the calculated DURxz values ​​along the plane (X, Z) as a function of transport unit density (ρ) obtained in a single-layer system (dashed line) and a double-layer system (solid line). These values ​​were obtained in a single-layer system irradiating a container carrying a single transport unit (1.1) with a unit height h11 = 260 cm, and in a double-layer system irradiating a container carrying two transport units (1.1, 1.2) (each transport unit having a unit height h11 = h12 = 260 cm, separated by a height gap hv = 15 cm). The scan width hx = 300 cm. Figure 7(a) shows that the DURxz obtained in the single-layer system is higher (worse) than that obtained in the double-layer system. Two-layer system

[0065] As shown in Figures 5(a) and 5(b) and Figure 5(e) and 5(f) As shown in the diagram, in a two-layer system, the transport units loaded in the shipping container must be irradiated twice, with the transport units being swapped between the top and bottom halves of the shipping container between the two irradiations (1.i). See Figure 12 above. Figures 13(a) to 13(f) The exchange of transport units (1.i) between the top and bottom portions of a transport container (5x) can be implemented using a swapping unit (9) located between a first transport container (5x) and a second transport container (5e), ​​the first transport container having previously been driven through the irradiation volume (Vx), and the second transport container being empty and ready to receive transport units from the first transport container. The swapping unit (9) collects the first transport unit (1.1) from the top half of the first transport container, lowers the first transport unit to the level of the bottom half of the transport container, and transfers the first transport unit (1.1) to the bottom portion of the second transport container. This operation can be repeated as needed to transfer all transport units from the first transport container to the second transport container. The aforementioned operations can be performed in any order desired by the operator. The newly loaded second transport container can be driven so that the transport units pass through the irradiation volume (Vx) a second time.

[0066] While not mandatory, it is preferred that, in a two-layer system, the shipping container includes a support element (5s) positioned within ±30 cm, preferably within ±20 cm, more preferably within ±10 cm, and most preferably within ±5 cm of the half-height (1 / 2h5) of the shipping container. This support element is defined as a plane perpendicular to the longitudinal axis (Z) and positioned at equal distances (1 / 2h5) from both the bottom and top ends. This allows the interchange of transport units between the bottom and top halves of the shipping container to deposit a second dose during the second pass, which is complementary to the first dose deposited during the first pass, thus resulting in a lower DUR value. Simultaneously, care should be taken to ensure that the total height (ht) is approximately centered on the irradiation axis (X). Therefore, the support element (5s) in the second shipping container is not necessarily at the same level as in the first shipping container.

[0067] If the shipping container is loaded with transport units of similar height, the support element (5s) of the second shipping container can simply be located in the same position as in the first shipping container. However, if transport units of different heights are loaded in the shipping container, as shown in Figure 12 and... Figures 13(a) to 13(f) As shown, where two transport units (1.1, 1.2) have different unit heights (h11, h12), the position of the support elements (5s) of the second transport container may have to differ from their positions in the first transport container. In another example, if the top half of the first transport container carries the first transport unit (1.1) with a unit height (h11), and the bottom half carries the second and third transport units (1.2, 1.3) with unit heights (h12, h13), where... The first shipping container includes a single (or set of) support elements (5s) on its top half to support the first transport unit (1.1), while the bottom half is provided with two (or sets of) support elements (5s) to support the second and third transport units (1.2, 1.3). Clearly, when exchanging transport units, the second shipping container must include two (or sets of) support elements (5s) on its top half to support the second and third transport units (1.2, 1.3), and a single (or set of) support element (5s) on its bottom half to support the first transport unit (1.1). The processing control unit (PCS) (7) can be configured to ensure that the second shipping container has support elements (5s) positioned as needed to facilitate the fastest possible exchange of transport units under optimal conditions.

[0068] Because the shipping containers (5) used in double-layer systems typically have a large shipping container height (h5) of about 500cm to 650cm, it is generally preferred to drive them using a conveyor (3) that includes an overhead track for stability reasons, on which the shipping containers (5) are suspended. Dose deposition distribution along the irradiation axis (X)

[0069] Figure 7(b) illustrates the dose deposition distribution entering the transport unit (1.i) via radiation (11x) along the irradiation axis (X). To reduce the difference ΔDx1 = DMx1 - Dmx1 obtained by exposing only a portion of the transport unit (see dashed and dotted lines in Figure 7(b)), irradiating the transport unit from different orientations may be preferred. In one embodiment shown in Figures 11(a) and 11(b), the conveyor may include a rotating element (3r) away from the irradiation volume (Vx) to rotate the transport container by an angle θ = 2π / M rad and drive the transport container (5) (M-1) times through the irradiation volume (Vx) again after each rotation, for a total of M passes. In practice, M can be equal to 2, where θ = π, thus exposing the diameter-opposite surfaces of the transport unit in two passes. By comparing ΔDx1 (obtained by irradiating only one part of the transport unit (dashed line, M=1, "θ=0" and "θ=π")) with ΔDx2 (obtained by irradiating two opposite parts (solid line, "M=2")) in Figure 7(b), it can be seen that the two passes significantly improve the uniformity of dose deposition distribution along the irradiation axis (X) when rotating θ=π. However, the processing time is correspondingly increased because the second rotation and passage through the transport container are very time-consuming.

[0070] In an alternative embodiment, the rotating element is located within the irradiation volume, such that each shipping container (5) rotates continuously or intermittently about the longitudinal axis (Z) while it is upright within the irradiation volume (Vx). For example, the conveyor may include a rotating element configured to rotate the shipping container (M-1) times, each rotation angle θ = 2π / M rad, so that M portions of the transport unit (1.i) loaded in the shipping container are successively exposed to the irradiation volume (Vx). This solution produces the same advantages in terms of enhanced uniformity as discussed previously with respect to Figures 11(a) and 11(b).

[0071] In another embodiment, the device may include a second radiation source configured to emit radiation along a second irradiation volume centered on a second irradiation axis, so as to irradiate a second portion of the transport unit (1.i). The second irradiation axis is preferably parallel to, and more preferably coaxial with, the first irradiation axis (X), and the irradiation occurs in the opposite direction to the irradiation performed by the first radiation source (11). This allows for the simultaneous irradiation of two opposing portions of the transport unit, thus correspondingly increasing throughput. However, this solution is significantly more expensive than previous solutions because it requires a second radiation source. A comparison of the double-layer system using shipping containers (5) with the current level of dual-track systems.

[0072] The essence of the invention, applied to a two-layer system (where transport units (1.i) are stacked one on top of another in a shipping container, rather than stacked on two overlapping tracks (3) separated by a separation distance (h3) from each other), is that the distribution of transport units can be modified and optimized to minimize the gap (hvi) between adjacent transport units (1.i, 1.(i+1)). This has several advantages.

[0073] First, the total clearance height (∑) can be made i The overall gap height (hv1) is minimized. The larger the total gap height, the greater the amount of wasted energy. In current-level stacked tracks, the individual gap height (hv1) is uncontrollable and depends on the unit height (h11) of the transport unit (1.1) loaded in the lower track, since hv1 = h3 - h11. On the one hand, for a two-layer system, the energy waste due to the large gap height (hv1) in current-level stacked tracks is demonstrated. • In Figure 10(a), the minimum dose (Dmx) deposited along the irradiation axis (X) is plotted as a function of the density of the transport cells for all locations along the vertical axis (Z), and on the other hand, • By comparing the minimum dose (Dmx) deposited along the irradiation axis (X) based on the position along the longitudinal axis (Z): two stacked transport units (1.1, 1.2) with the same unit height (h11 = h12 = 100 cm) loaded in the transport container (5) (solid line) according to the invention drawn in Figure 8(b), and the same two transport units (1.1, 1.2) loaded in two current process level stacked tracks (solid line) in Figure 9(b).

[0074] As can be seen from Figures 8(b) and 9(b), for the same irradiation beam (here, a 7 MeV X-ray beam), the total minimum dose Dmx, which includes 40 kGy to 50 kGy, is deposited into each transport unit when it is loaded into the transport container, thereby minimizing the gap height (hv1 = 15 cm), while the total minimum dose Dmx deposited into each transport unit loaded in the stacked orbit includes only 20 kGy to 30 kGy. The difference in deposited dose between the two is wasted in stacked orbits of current technology. The same conclusion can be drawn from Figure 10(a) by comparing the solid line according to the invention with the dashed line according to the current technology of a dual-stacked orbit system. It is thus concluded that, for the device according to the invention, a lower energy radiation source (11) can be used, thus reducing the cost of the radiation source (11), or the transport container can be driven through the irradiation volume (Vx) at a higher rate, thus increasing the throughput. In both cases, the invention can produce significant savings in energy, time, and cost. The total minimum dose Dmx, represented by the solid lines in Figures 8(b) and 9(b), is the sum of the minimum doses deposited into the transport unit along the irradiation axis (X) when the transport unit (1.1) is positioned in the lower half of the transport container or in the lower track (dashed line, "d" = downward) and when it is positioned in the upper half of the transport container or in the upper track (dashed line, "u" = upward).

[0075] Secondly, for two superimposed tracks at the current technological level, for all unit heights (h1i) below the separation distance (h3) between the two tracks (i.e., The number N of transport units that can be stacked on top of each other is limited to N=2. By using the shipping container according to the invention, more than two transport units can be stacked on top of each other, as long as the total height (ht) remains below the height of the shipping container (h5) (i.e., ht...). <h5)。

[0076] For example, two stacked tracks separated by a distance h3 = 300 cm can be compared to a shipping container (5) with a container height h5 = 600 cm. If a shipping unit (1.i) with a unit height h1i = 120 cm must be processed, two shipping units can be irradiated at once using two stacked tracks with a gap height hv1 = 300 - 120 = 180 cm. Exposure ratio This equals 2 x 120 / (2 x 120 + 180) = 57% of the total height. This exposure ratio defines the proportion of cargo distributed along the total height (ht). Therefore, it means that 43% of the total height (ht) is made up of gaps, thus wasting 43% of the emitted radiant energy.

[0077] For a shipping container with a height h5 = 600 cm, four transport units with a unit height h1.i = 120 cm can be loaded into one shipping container, with a gap of hvi = 15 cm between every two transport units, thus producing only Total gap height, of which exposure ratio Only 9% of the total height (ht) is comprised of gaps. This example demonstrates the advantages of the present invention over current technology in stacked track systems, resulting in twice the throughput, where four transport units are irradiated in each pass instead of two transport units for a stacked track, and where the exposure ratio is 34% higher, resulting in corresponding energy savings.

[0078] Figures 8(c) and 9(c) plot the DURx values ​​along the irradiation axis (X) as a function of the unit height (h1i) measured along the longitudinal axis (Z). It can be seen that, for both the shipping container and the stacked track, the value of DURx = DMx / Dmx is less than 1.3, which is perfectly acceptable. Figure 10(b) plots the DURx values ​​along the irradiation axis (X) as a function of the density of transport units in the double-layer system (solid line) and double-stacked track system (dashed line) discussed according to reference Figures 8 and 9 of the present invention. It can be seen that the DURx values ​​according to the present invention maintain the DURx values ​​obtained in the case of the double-stacked track type facility.

[0079] According to the present invention, preferably, the dose uniformity ratio (DURx) is not more than 1.4, more preferably not more than 1.3, and more preferably not more than 1.15, in order to achieve 0.1 g / cm³. 3 The uniform density, dose uniformity ratio is defined as the ratio (DMx / Dmx) of the maximum dose (DMx) to the minimum dose (Dmx) deposited into the cargo along the irradiation axis (X) between the bottom and top of the transport unit (1.i) on the longitudinal axis (Z).

[0080] Third, by using shipping containers, a suspended track can be used to drive the containers loaded with transport units through the irradiation volume (Vx), instead of a motorized roller conveyor as is used in conventional facilities. Suspended tracks are advantageous because they require fewer moving and motorized parts exposed to the corrosive environment within and around the irradiation volume (Vx). Unlike roller conveyors, suspended tracks drive the shipping containers by means of a chain or cable pulled by a motor, which can be positioned far from the irradiation volume (Vx), thus extending equipment life and reducing the number of failures requiring conveyor shutdowns. Note that roller conveyors can be used in conjunction with this invention if desired. Method of irradiating goods with radiation

[0081] The apparatus of the present invention can be advantageously used in a method for irradiating goods contained in a transport unit (1.i) with radiation selected from X-rays and electron beams. The method includes the following steps: • Provide the equipment as discussed above. • The transport unit (1.i) is loaded onto the shipping container (5) which is equipped with support elements (5s) that support the transport unit (1.i) as discussed above. • Drive the shipping container (5) along the transverse axis (Y) through the irradiation volume centered on the irradiation axis (X) to expose the first part of the cargo. • When the shipping container (5) is driven through the irradiation volume, the transport unit (1.i) is irradiated with radiation (11x).

[0082] To reduce the DURx value, it is preferable that, after passing through the irradiation volume once to expose a portion of the cargo, the thus irradiated shipping container (5x) is rotated by the rotation angle (θ) and driven back through the irradiation volume to expose different portions of the cargo contained in the transport unit (1.i). Alternatively, the shipping container may be rotated within the irradiation volume (Vx).

[0083] In a preferred embodiment, the method applies double-layer irradiation to the shipping container (5), and the device includes a swapping unit (9) as previously discussed. In this embodiment, the method includes the following steps: • Transfer the transport unit (1.i) loaded in the upper half of the first shipping container (5) to the lower half of the second shipping container (5), and • Transfer the transport unit (1.i) loaded in the lower half of the first shipping container (5) to the upper half of the second shipping container (5), and • Drive the second shipping container through the irradiation volume (Vx). Conclusion

[0084] The advantage of this invention is that all irradiation parameters (including radiation energy, scanning horn (11h), and irradiation axis (X)) can remain constant throughout the entire process of irradiating transport units with different unit heights (h1i) and densities. The drive rate of the shipping container through the irradiation volume (Vx) is preferably adapted to the density of the transport units loaded in each shipping container (5).

[0085] Compared to facilities with current technology levels, throughput can be increased because more than two transport units can be loaded into one shipping container, provided that the total height (ht) remains less than the height of the shipping container (h5) (i.e., ht <h5)。

[0086] Due to the total clearance height It can reduce, and the exposure rate The corresponding increase results in a significant enhancement in the efficiency of the process compared to the current level of two-track stacked systems, with less radiation wasted through the gap between the two transport units.

[0087] The equipment and method of this application can be applied to both single-layer and double-layer irradiation techniques.

[0088] Compared to current technology-level equipment using the same radiation source (11), a higher minimum dose (Dmx) can be deposited using the equipment according to the invention.

Claims

1. An apparatus for irradiating a cargo with radiation (11x) selected from X-rays or electron beams, said apparatus comprising: • A radiation (11x) source (11) selected from X-rays or electron beams, the radiation source being configured to emit the radiation (11x) along an irradiation volume (Xv) centered on the irradiation axis (X). • A conveyor (3), configured to drive goods loaded in two or more transport units (1.i) having a unit height (h1i) through the irradiated volume along a transverse axis (Y) perpendicular to both the irradiation axis (X) and the longitudinal axis (Z), so that a first portion of the goods is exposed to the radiation, the unit height being measured along the longitudinal axis (Z) perpendicular to both the irradiation axis (X). The transport unit (1.i) is loaded in a shipping container (5) having a shipping container height (h5), which is measured along the longitudinal axis (Z) from the bottom end at the bottom height (H50) to the top end at the top height (H51), wherein the shipping container height (h5) is the difference between the top height (H51) and the bottom height (H50) (h5 = H51 - H50). Furthermore, the conveyor (3) is configured to drive the shipping container (5) carrying N transport units (1.i) loaded with the goods, wherein, • The shipping container includes a support element (5s) for supporting the transport unit (1.i), wherein the support element is capable of being positioned at different levels along the shipping container height (h5). • The shipping container (5) can hold N transport units, of which And N ≥ 1, the transport units are arranged vertically to extend the total height (ht), which is measured along the longitudinal axis (Z) from the bottom of the first transport unit (1.1) positioned closest to the bottom unit height (Ht0) of the container (5) to the top of the Nth transport unit (1.N) positioned closest to the top unit height (Ht1), wherein the total height (ht) is the difference between the top unit height (Ht1) and the bottom unit height (Ht0) (ht = Ht1 - Ht0) and wherein each transport unit (1.i) is held in place in the container (5) by one or more support elements (5s) such that The total height (ht) is between 40% and 100% of the height of the shipping container (h5) (i.e., 40% h5 ≤ ht ≤ h5). o The N transport units (1.1-1.N) loaded in the shipping container span at least 70% of the total height (ht) (i.e., ≥ 70% ht), The total height (ht) is centered relative to the height of the shipping container (h5), with an error within [missing information]. Within 20% (i.e., (Ht1 - ½ht) = ½h5) 20%) The device is configured to connect the support element to the shipping container at different levels along the height of the shipping container, so that the position of the transport unit can be customized according to any standard.

2. The device according to claim 1, wherein, The total height (ht) includes between 60% and 80% of the height of the shipping container (h5); and / or Wherein, N transport units (1.1-1.N) loaded in the shipping container span at least 80% of the total height (ht); and / or The total height (ht) is centered relative to the height of the shipping container (h5), with an error within ±10% (i.e., (Ht1 - ½ ht) = ½ h5 ± 10%).

3. The device of claim 1, further comprising a processing control unit (PCS) (7), the processing control unit being configured to perform one or more of the following actions: • Measure the unit height (h1.i) of the transport unit before loading the transport unit (1.i) into the shipping container (5). • Weigh the transport units (1.i) and determine their corresponding densities. • Determine the target total height (ht0) based on the irradiated volume height measured along the longitudinal axis (Z) and select the N transport units (1.i-1.N) to be loaded into each shipping container (5) to achieve the total height (ht), which is lower than the height of the shipping container (h5) and included in the target total height. Within 10%: (i.e., ht = ht0 10% < h5), • For each shipping container, the height of the irradiated volume is optimized to accommodate the total height (ht) of the transport unit (1.i) loaded in the corresponding shipping container (5). • Determine the loading plan for the transport units, which specifies which transport units (1.i) will be loaded into which shipping containers. Based on the thus measured unit height (h1.i) of the transport unit, in order to maximize the fill ratio (ht / h5) of the total height (ht) to the container height (h5), and / or Based on the density thus determined, the N transport units (1.1-1.N) loaded in the shipping container have similar densities, with an error within a certain range. Within 25%, and • Assign a position optimized according to the unit height of the transport unit (1.i) to each support element (5s) so that the total clearance separating every two adjacent transport units (1.i, 1.(i+1)) in the same shipping container is ( The gap ratio between the total height (ht) and the total height (ht) ) minimized.

4. The device according to claim 3, wherein, The loading scheme assigns each transport unit (1.i) a loading position in the shipping container along the longitudinal axis.

5. The device according to claim 3 or 4, comprising a loading station (4) configured to load the transport unit (1.i) onto the shipping container (5) according to the loading scheme.

6. The device according to claim 5, wherein, The loading station is configured to load the transport unit (1.i) onto the shipping container (5) according to the loading location.

7. The device according to claim 5, wherein, The loading station (4) is configured to position the support element (5s) at a location optimized according to the unit height of the transport unit (1.i), so that the gap ratio ( ) minimized.

8. The device according to any one of claims 3-4 and 6, wherein, Transport units (1.i) of similar density are loaded into one or a series of shipping containers (5), and wherein the conveyor is configured to drive the one or the series of shipping containers through the irradiated volume at a speed that depends on the average density of the transport units (1.i) loaded in the one or the series of shipping containers.

9. The device according to any one of claims 3-4 and 6-7, comprising a rotating element (3r) configured to rotate the shipping container (5) by a certain rotation angle. ), and among them, The conveyor (3) is configured to drive the shipping container through the irradiated volume several times, so that each time the shipping container rotates the rotation angle, the second, third, and other portions of the cargo are exposed to the radiation.

10. The device according to any one of claims 3-4 and 6-7, configured to perform any one of the following: • The shipping container (5) is subjected to single-layer irradiation using a scanning horn (11h) configured for overscanning, such that the irradiation volume includes the entire height of the shipping container (h5), and the first portion of the cargo of all N transport units (1.i) loaded in the shipping container (5) is exposed to the required dose in a single pass, or • The shipping container (5) is subjected to double-layer irradiation using a scanning horn (11h) configured for under-scanning, such that the irradiation volume does not include the entire height of the shipping container (h5), and the first portion of the cargo of the N transport units (1.i) loaded in the shipping container (5) is exposed to the required dose in two passes. For the first shipment, the first selection is the transport unit loaded in the upper half of the shipping container (i.e., above 1 / 2 h5), and the second selection is the transport unit loaded in the lower half of the shipping container (i.e., below 1 / 2 h5). For the second pass, the first selection is loaded into the transport unit in the lower half of the shipping container, and the second selection is loaded into the transport unit in the upper half of the shipping container.

11. The apparatus of claim 10, the apparatus being configured for double-layer irradiation of the shipping container (5), the apparatus comprising a switching unit (9) configured to: transfer the transport unit (1.i) to the lower half of the first shipping container (5) and the transport unit (1.i) to the upper half of the second shipping container (5); and drive the second shipping container through the irradiation volume.

12. The device according to any one of claims 3-4, 6-7 and 11, wherein, The conveyor (3) is in any of the following forms: • Elevated track, on which the shipping container (5) is suspended and driven, or • Roller conveyor, on which the shipping box (5) stands upright and is driven.

13. The device according to any one of claims 3-4, 6-7 and 11, wherein, • The height (h5) of the shipping container is between 500 cm and 650 cm. • The height (h1i) of the transport unit is between 50 cm and 380 cm. • The gap (hvi) separating two adjacent transport units (1.i, 1.(i+1)) in the same shipping container is included between 8 cm and 30 cm.

14. The device according to claim 13, wherein, The height (h5) of the shipping container is between 550 cm and 600 cm; and / or Wherein, the height (h1i) of the transport unit is between 100 cm and 280 cm; and / or The gap (hvi) separating the two adjacent transport units (1.i, 1.(i+1)) in the same shipping container is between 15 cm and 25 cm.

15. The device according to any one of claims 3-4, 6-7, 11, and 14, wherein, The dose uniformity ratio (DURx) should not exceed 1.4 to achieve 0.1 g / cm³. 3 The uniform density is such that the dose uniformity ratio is defined as the ratio (DMx / Dmx) of the maximum dose (DMx) to the minimum dose (Dmx) deposited into the cargo along the irradiation axis (X) between the bottom and top of the transport unit (1.i) on the longitudinal axis (Z).

16. The device according to claim 15, wherein, The dose uniformity ratio (DURx) does not exceed 1.

3.

17. The device according to claim 15, wherein, The dose uniformity ratio (DURx) does not exceed 1.

15.

18. A method for irradiating cargo loaded in a transport unit (1.i) with radiation (11x) selected from X-rays or electron beams, the method comprising the steps of: • Provide the device according to any one of claims 1-17, • Load the transport unit (1.i) onto the shipping container (5) provided with the support element (5s), which supports the transport unit (1.i) as described in claim 1. • Drive the shipping container (5) along the transverse axis (Y) through the irradiation volume to expose a first portion of the cargo. • When the shipping container (5) is driven through the irradiation volume, the transport unit (1.i) is irradiated with the radiation (11x).

19. The method according to claim 18, wherein, After exposing a portion of the cargo by passing through the irradiation volume once, the shipping container (5x) is rotated by the rotation angle ( And drive back through the irradiated volume to expose different parts of the cargo contained in the transport unit (1.i).

20. The method according to claim 18, wherein, The conveyor is configured to double-irradiate the shipping container (5), wherein the device includes a switching unit (9), and wherein the method includes: • The transport unit (1.i) to be loaded in the upper half of the first shipping container (5) is transferred to the lower half of the second shipping container (5), and • The transport unit (1.i) to be loaded in the lower half of the first shipping container (5) is transferred to the upper half of the second shipping container (5), and • Drive the second shipping container through the irradiation volume (Vx).

21. The method according to any one of claims 18 to 19, wherein, Regardless of the height (h1i) of the transport unit (1.i) and the density of the cargo, the scanning horn (11h) and the irradiation axis (X) remain constant throughout the process.

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