Assembly and methods for spray drying

Abstract

The present invention relates to an assembly (38) for installation into a support structure (39) comprising a spray drying chamber (2a, 2b) and a product separator (35a, 35b), or a section thereof or a frame therefor (47a, 47b, 47c, 47d), to form a spray drying apparatus that can be used to produce a spraydried product and an outlet gas using a liquid feed and a drying gas. The present invention also relates to a method of producing the assembly (38), a process for producing the spray drying apparatus comprising installing the assembly (38) into a support structure (39), a method of spray drying using the spray drying apparatus, and a method of reusing the spray drying apparatus comprising uninstalling the assembly from the support structure and installing a new assembly.

Description

[0001] ASSEMBLY AND METHODS FOR SPRAY DRYING

[0002] TECHNICAL FIELD OF THE INVENTION

[0003] The present invention is in the technical field of spray drying. In particular, the present invention is related to an assembly that can be installed into a support structure to form a spray drying apparatus. The present invention is also related to methods for producing the assembly, methods for producing the spray drying apparatus by installing the assembly into the support structure, and methods using the spray-drying apparatus comprising the installed assembly to produce a spray-dried product. Further, the present invention relates to methods of removing the assembly from the support structure and installing a further assembly, such that further spray drying with a different product can be undertaken.

[0004] BACKGROUND OF THE INVENTION

[0005] Spray-drying is a technology that is widely used for powder production in a large number of industries, including the chemical, food and pharmaceutical industries. Particularly in the pharmaceutical industries there is a need for aseptic spray drying in which the entire spray drying process is conducted under aseptic processing conditions, so that sterile powders suitable for medical use can be produced.

[0006] Aseptic spray drying is an enabling platform for, e.g., new modalities by allowing particle engineering needed to formulate complex injectables such as those for high load subcutaneous delivery. However, current aseptic spray drying technology requires complex facilities and large equipment requiring high capital investment and / or complex in loco sterilization procedures leading to high operational costs. This complexity can also exacerbate issues such as cost and supply disruption when problems arise, and batches of product are lost.

[0007] Single-use bioreactors have been developed for aseptic processing for use in biomanufacturing; the first single-use bioreactor was launched in 1996 by Wave Biotechnology” (Subramanian G. “Continuous Biomanufacturing: Innovative Technologies and Methods”, Wiley VCH Verlag GmbH & Co. KGaA: Weinheim, Germany, 2017: 151-152). Further, in the context of spray-drying, WO 2019 / 043007 A1 (Capsugel Belgium NV) describes the use of a single-use drying chamber and other single-use components, each of which can be pre-sterilized and sterile packaged for use. After performing spray-drying, all or some of these components can be replaced by removing a new, unused component from sterile packaging and installing the new component in place of the used component. However, these options fail to address completely the problems of the complexity and cost of the equipment and its operation. For example, with the single-use components of WO 2019 / 043007 A1 it is still necessary to remove these from their packaging prior to use and expose them to the external environment of the apparatus. This means that the environment of the apparatus must still be carefully cleaned and controlled to ensure that the components are not contaminated during their installation.

[0008] As a result, although single-use components have been widely adopted for biological and / or aseptic processing in other technologies, the size and complexity of the spray drying equipment means that they have had limited application for aseptic spray drying. (In particularly cleaning during the processing of biologies can be very complex). Further, it is even more complex to handle potent compounds using current aseptic spray drying techniques because of the conflicting requirements in under / over pressure of the chamber vs the environment arising from the requirements of sterility and personnel health and safety, respectively.

[0009] Accordingly, there is a need in the art for new products and methods to address these challenges.

[0010] SUMMARY OF THE INVENTION

[0011] In a first aspect the present invention provides an assembly for installation into a support structure comprising a spray drying chamber and a product separator, or a section thereof or frame therefor, to form a spray drying apparatus for producing a spray-dried product and an outlet gas using a liquid feed and a drying gas, the assembly comprising:

[0012] - a gas distributor and an atomizer, the gas distributor and the atomizer being for attachment to the spray drying chamber of the support structure;

[0013] - one or more inlet conduits comprising a first inlet conduit for supplying the drying gas to the gas distributor;

[0014] - an outlet part for attachment to the product separator, or section thereof or frame therefor, of the support structure;

[0015] - one or more outlet conduits comprising a first outlet conduit comprised in the outlet part for conducting the outlet gas away from the spray drying apparatus; and

[0016] - a container arranged between the gas distributor, the atomizer, and the outlet part and connected directly or indirectly thereto, the container comprising one or more container walls that define at least a chamber part and a product separator part, wherein the chamber part is for lining the spray drying chamber of the support structure and the product separator part is for lining the product separator or section thereof of the support structure, or for attachment to the frame of the support structure.

[0017] In particular, the assembly of the invention can be used to produce particles by spray drying solutions or suspensions of ingredients (especially pharmaceutical ingredients and / or potent (toxic or potentially toxic) ingredients, which require particular care in production and handling) with the assurance of sterility and / or containment. The assembly can be installed on the support structure to form a spray drying apparatus, and can be used to produce the particles in a closed or partially closed system where any exchange of fluids (liquids, gases, powder streams) with the ancillary equipment (e.g. gas feed sources) and / or the environment in which the assembly and apparatus are situated, is mediated by isolation devices, so that the requirements for a sterile product and / or environmental control are met. These features additionally avoid the need for complex in situ cleaning and sterilization of equipment between processing runs. Therefore, equipment can be readily re-used by removing a used assembly, and installing a second assembly, ensuring less down-time between processing runs. Accordingly, in a second aspect the invention provides a method of producing an assembly as described above, the method comprising connecting the container directly or indirectly to the gas distributor, the atomizer, and the outlet part to produce the assembly. Optionally, the method may comprise sterilizing the assembly.

[0018] In a third aspect, the invention provides a process for producing a spray drying apparatus, the process comprising installing an assembly as described above into a support structure comprising a spray drying chamber and a product separator or section thereof, or frame therefor, wherein the process comprises:

[0019] - connecting the gas distributor and the atomizer directly or indirectly to the spray drying chamber;

[0020] - connecting the outlet part directly or indirectly to the product separator or section thereof, or frame therefor;

[0021] - fitting the chamber part of the container into the spray drying chamber; and

[0022] - fitting the product separator part into the product separator or section thereof, or attaching the product separator part to the frame.

[0023] In a fourth aspect the present invention provides a spray drying apparatus comprising an assembly as described above installed into a support structure comprising a spray drying chamber and a product separator or section thereof, or frame therefor.

[0024] In a fifth aspect the present invention provides a method of spray drying comprising using a spray drying apparatus according to the fourth aspect to produce the spray-dried product and the outlet gas from the liquid feed and the drying gas.

[0025] In a sixth aspect the present invention provides a method of reusing the spray drying apparatus used in the method of the fifth aspect, the method comprising uninstalling an assembly after use of the spray drying apparatus, and installing a further assembly as described above into the support structure. FIGURES

[0026] To assist understanding of the present disclosure and to show how embodiments may be put into effect, reference is made by way of example only to the accompanying drawings in which:

[0027] Figure 1 provides a schematic of a cross-section of an assembly according to an embodiment of the invention.

[0028] Figure 2 provides a schematic of an assembly according to an embodiment of the invention.

[0029] Figure 3 provides a schematic of a cross-section of an assembly according to an embodiment of the invention installed in a support structure.

[0030] Figure 4 provides a schematic of an assembly according to an embodiment of the invention installed in a support structure.

[0031] Figure 5 provides a diagram showing the assembly and an exploded view of the assembly installed in the support structure.

[0032] Figures 6A to 6C show an example of a gas distributor. Figures 6A and 6B provide detailed views of the gas distributor with an imbedded nozzle, while the flow of gas and liguid feed through the gas distributor is shown in Figure 6B. Figure 6C provides an external view of the gas distributor.

[0033] Figures 7A and 7B show an example of an outlet part that is a cyclone outlet part. The flow of the outlet gas through the cyclone outlet part is shown in Figure 7B. Figure 8 shows an example in which an isolation device comprises an insulating layer to reduce heat loss from the drying gas.

[0034] Figure 9 shows an example of a gas distributor in which the isolation device is part of the gas distributor.

[0035] Figure 10A and 10B shows an example of a gas distributor comprising a telescopic heat shield. In Figure 10A the heat shield is retracted (e.g. , for storage, transport or sterilization). In Figure 10B the heat shield is shown expanded, as in use during spray drying.

[0036] Figure 11 shows an example in which the product separator part of the container is attached to a frame of the support structure. DETAILED DESCRIPTION OF THE INVENTION

[0037] The present invention will now be described with reference to the embodiments of the invention shown in the Figures. These references are by way of example only and are not intended to limit the invention. Further, a number of advantages are discussed herein in relation to the invention. The invention is not limited to achieving every advantage described.

[0038] The description of the invention provided herein uses the terms “first” and “second” e.g., referring to “a first inlet conduit”, “a second inlet conduit”. The use of the terms “first” and “second” herein is for identification purposes only and does not refer to any order of importance or use.

[0039] The description of the invention provided herein also refers to “connecting” or “connected”, “sealing” or “sealed”, “joining” or “joined”, “attaching” or “attached”, when referring to the attachments between parts of the assembly and the attachments between the assembly and parts thereof to the support structure, and parts thereof, and to e.g., the gas source, the liquid feed source, and the gas exhaust or recycling unit. Except where specified otherwise, it should be understood that these attachments can be direct or indirect, e.g., via an intermediate part I component.

[0040] As described above, the present invention provides as assembly that is for installation into a support structure to form a spray drying apparatus which can then be used to produce a spray-dried product and an outlet gas using a liquid feed and a drying gas. The support structure comprises a spray drying chamber and a product separator, section of a product separator, or a frame for a product separator. In particular, the assembly comprises:

[0041] - a gas distributor and an atomizer, the gas distributor and the atomizer being for attachment to the spray drying chamber of the support structure;

[0042] - one or more inlet conduits comprising a first inlet conduit for supplying the drying gas to the gas distributer;

[0043] - an outlet part for attachment to the product separator or section thereof, or frame therefor, of the support structure; - one or more outlet conduits comprising a first outlet conduit comprised in the outlet part for conducting the outlet gas away from the spray drying apparatus; and

[0044] - a container arranged between the gas distributor, the atomizer, and the outlet part and connected directly or indirectly thereto, the container comprising one or more container walls that define at least a chamber part and a product separator part, wherein the chamber part is for lining the spray drying chamber of the support structure and the product separator part is for lining the product separator or section thereof of the support structure, or for attachment to the frame of the support structure.

[0045] The assembly comprises a gas distributor (1 ) and an atomizer (22), e.g., as shown in Figures 1 and 2. As indicated above, spray drying is a well-established technology, in which a spray dried product (a powder) is formed by atomizing a liquid feed to create droplets, and the droplets are dried using a drying gas in a spray drying chamber. As such, suitable gas distributors and atomizers for use in the present invention are known and are commercially available. The gas distributor and atomizer of the assembly are usually together as one part, with the atomizer being part of the gas distributor, so that attachment of the gas distributor to the container also results in the atomizer being attached to the container. (For example, the one part may be a gas distributor with an imbedded atomizer e.g., as shown in Figures 6A to 6C.)

[0046] The atomizer can comprise a one-fluid nozzle, such as a pressure nozzle or a rotary nozzle, or a two-fluid nozzle (a co-axial nozzle). Preferably the atomizer comprises a two-fluid nozzle, which atomizes the liquid feed using an atomizing gas. In this embodiment, the assembly may also then require a third inlet conduit for providing an atomizing gas to the atomization nozzle, as is discussed further below. An example of a two-fluid nozzle is shown in Figures 6A and 6B.

[0047] Where the gas distributor and atomizer of the assembly are together as a single part, the single part can be a subassembly of the gas distributor and the atomizer or atomizer parts (e.g. nozzle tip (21 ) and nozzle cap (20)) or the single part can be formed as a single unit (single assembly), e.g. formed by 3D printing. A single unit may be preferred for simplicity, ease of use, and / or increased disposability.

[0048] The assembly comprises one or more inlet conduits each of which may be defined as comprising a proximal part and a distal part. The inlet conduits are for supplying the elements / component (drying gas, liquid feed I feed reactants etc.) necessary for the spray drying process to the assembly. The assembly is connected to external sources of these components prior to use. In particular, the first inlet conduit described herein is for supplying the drying gas to the gas distributor. The first inlet conduit can be connected at its proximal part to the gas distributor.

[0049] In one example, the assembly comprises a second inlet conduit for supplying the liquid feed to the atomizer. This second inlet conduit can be connected at its proximal part to the atomizer.

[0050] In an alternative example, the assembly itself may comprise a feed reactor and a feed conduit for delivering feed from the feed reactor to the atomizer. In this embodiment the one or more inlet conduits may comprise one or more feed reactor inlet conduits for delivering components of the feed (reactant) to the feed reactor. Such feed reactor inlets can be connected at their proximal parts to the feed reactor.

[0051] In examples where the atomizer comprises a two-fluid nozzle, the assembly may further comprise a third inlet conduit for supplying an atomizing gas to the atomizer. This third inlet conduit can be connected at its proximal part to the atomizer.

[0052] Examples of the one or more inlet conduits are shown in Figure 1 (see parts 23 to 25).

[0053] The distal part of the conduits can be used for connecting, directly or indirectly (e.g., via the isolation device discussed below), to the sources of the components needed for spray drying (e.g., a liquid feed source, a drying gas source, an atomizing gas source, a feed reactant source etc.), which are external to the assembly.

[0054] The assembly also comprises an outlet part (e.g., as shown as part 26 in Figure 1 ) for attachment to the product separator or section thereof, or frame therefor, of the support structure, and to one or more outlet conduits. The one or more outlet conduits comprise a first outlet conduit for conducting the outlet gas, produced during spray drying, away from the spray drying apparatus (e.g., away from the product separator part of the container, discussed below).

[0055] The first outlet conduit is comprised in the outlet part (e.g., as shown as part 26 in Figure 1 ). The first outlet conduit may comprise a proximal part and a distal part and be connected at its proximal part to the outlet part, allowing the distal part to be used to connect, directly or indirectly (e.g., via the isolation device discussed below), to a gas exhaust unit or a gas recycling unit that is external to the assembly. The outlet part may also be formed as a single part (e.g., by 3D printing) or be a subassembly of parts (e.g., a cap for the product separator and an outlet conduit).

[0056] In one example the assembly also comprises a second outlet conduit for removing the spray dried product from the spray drying apparatus (e.g., from the container, discussed below). The second outlet conduit may comprise a proximal part and a distal part and be connected at its proximal part to the container, allowing the distal part to be used to connect, directly or indirectly (e.g., via the isolation device discussed below), to a product collection part, e.g., a product container.

[0057] The assembly further comprises a container (e.g., as shown as part (27) in Figure 1 ) arranged between the gas distributor, the atomizer, and the outlet part and connected directly or indirectly thereto. The container comprises one or more container walls (e.g., as shown as parts (28 and 29) in Figure 2) that define at least a chamber part (e.g., as shown as part (3) in Figure 1 ) and a product separator part (e.g., as shown as part (31 ) in Figure 1 ). It will be understood that the container is directly or indirectly connected to the gas distributor, the atomizer and the outlet part such that the inlet gas and the atomized droplets can be fed into the container. As noted above, in a preferred embodiment the gas distributor and atomizer of the assembly may be together in a single part that can be connected directly or indirectly to the container. It will be understood that the connections seal the parts together such that there is no ingress of contaminants such as microorganisms or loss of the components of the spray drying process during spray drying through the connection, e.g., the connections are airtight.

[0058] The container is intended to provide a continuous lining to the spray drying chamber and the product separator or section thereof of the support structure, or to provide a continuous lining to the spray drying chamber joined to a product separator part that is a product separator, which attaches to the product separator frame of the support structure.

[0059] The chamber part of the container is for lining the spray drying chamber of the support structure. It will be understood that the container will be directly or indirectly attached to the atomizer and the gas distributor such that during spray drying the drying gas and the droplets of liquid feed from the atomizer will feed into chamber part of the container (as installed on the spray drying chamber of the support structure) and the droplets will be dried to form the spray dried product.

[0060] The product separator part of the container is for lining the product separator or section thereof of the support structure, or for attaching to the product separator frame of the support structure. Accordingly, in one example the support structure comprises a product separator and the product separator part of the container is for lining the product separator (e.g. as is shown in Figure 5). In another example, the support structure provides a frame for a product separator and product separator part of the container provides the product separator (e.g. as is shown in Figure 11 ).

[0061] In a further example, the support structure provides (a) a frame for a first section of the product separator; and (b) a second section of the product separator, while the product separator part of the container provides the first section of the product separator and a segment for lining the second section of the product separator.

[0062] In particular, where the product separator of the apparatus is a cyclone (i.e., comprising a cyclone barrel and a cyclone cone), for ease of assembly it is preferred that the product separator part of the container provides the cyclone and the support structure comprises a frame for the cyclone, or the product separator part of the container provides the cyclone barrel attached to a lining for the cyclone cone, and the cyclone cone is provided by the support structure. In these embodiments the cyclone or cyclone barrel of the product separator part of the container are rigid, while the lining for the cyclone cone is flexible. Suitable materials for these are discussed further below.

[0063] It will be understood that the container will be directly or indirectly attached to the outlet part comprising the first outlet conduit such that during spray drying the outlet gas from the product separator part (as installed on the product separator of the support structure) can flow away from the assembly through the first outlet conduit.

[0064] In particular, the product separator is for separating the spray dried product from the drying gas and may be a bag filter, an electrostatic separator, or a cyclone. In a preferred embodiment the product separator is a cyclone.

[0065] The container can be formed as a single part or can be a sub-assembly of parts (that may be made from different materials), provided that it is able to provide the continuous lining and / or parts mentioned above.

[0066] The outlet part to which the container is directly or indirect attached and which is for attachment to the product separator or section thereof, or frame therefor of the support structure, can be used to provide the necessary geometry for the container in order to ensure product separator efficiency, e.g., efficiency of the cyclone. This may be particularly advantageous in embodiments where the container wall(s) that define the product separator part are flexible, as discussed below. The container may be directly or indirectly attached to the gas distributor, atomizer, and / or outlet part with a permanent fixture like a seal obtained through hot sealing or an adhesive (such as high-density polyethylene thermal glue), or with a non-permanent fixture, such as a mechanical fixture (e.g., such as a fixture comprising an O-ring). As described above, it will be understood that it is particularly important that the fixing is sufficient to prevent any of the components of the spray-drying process from escaping from the assembly through these fixings, and / or avoid contaminants, e.g., microorganisms, from the outside environment affecting the aseptic environment inside the assembly, e.g., the fixing is airtight.

[0067] The gas distributor may comprise a heat shield to protect the chamber part of the container during spray drying from the heat of the drying gas as it enters the chamber from the gas distributor. In particular, the chamber part of the container can comprise flexible portions made from polymeric material (suitable for lining the spray drying chamber of the support structure) that can be sensitive to the high temperature of the drying gas as it exits the gas distributor.

[0068] In use, the heat shield projects from the gas distributor into the spray drying chamber. The length of the heat shield will impact the size of the powder particles produced in the chamber. Longer shields allow larger droplets to be dried and thus larger powder particle sizes.

[0069] The heat shield may be manufactured as a separate part and then fitted to the gas distributor as a subassembly.

[0070] The container may be attached to the heat shield itself, such that in use the heat shield protects the container by distancing the container from the gas exiting the gas distributor into the chamber. Alternatively, the container may be attached to the gas distributor with the heat shield providing a barrier between the gas exiting the gas distributor into the chamber and the container.

[0071] In a preferred example, the heat shield can be telescopic, as is shown in Figures 10A and 10B. In this embodiment the heat shield can be retracted, as shown in Figure 10A, during sterilization, storage, or transportation, and then extended (to the required length), as shown in Figure 10B, during use.

[0072] The one or more container walls may comprise one or more flexible portions. As a result, the assembly can exist in at least two arrangements, the at least two arrangements comprising an installed form (i.e. , the form in which the assembly exists when installed on the support structure) and a collapsed form in which the dimensions of the container are reduced as compared to the installed form. For example, the collapsed (or partially collapsed) form is shown on the left in Figure 5, while the installed form is shown in Figure 2. In particular, the ability for the assembly to be in a collapsed form is advantageous in sterilization, storage, transport, and use, as the assembly takes up less space, and is easier to install.

[0073] The one or more flexible portions may account for 60% or more, preferably 70% or more, most preferably 75% or more of the total surface area of the one or more container walls. In particular, one advantage of the invention is that the assembly can be sterilized off-line. Although large off-line sterilization facilities are available, such as purpose-built autoclaves, these percentages can allow the assembly in collapsed form to be sterilized in the standard autoclaves or standard sterilization facilities that are more readily available. Moreover, the flexible portions of the walls may be thinner than those of the standard stainless steel spray drying chamber, allowing better penetration of radiation and more efficient sterilization.

[0074] The one or more flexible portions may be flexible portions of the one or more container walls that define the chamber part and the product separator part. Accordingly, the flexible portions may also facilitate the use of the container in lining the spray drying chamber and the product separator or section thereof of the support structure.

[0075] The container walls may be made of various materials that provide the necessary properties in order for the assembly to perform its function, especially the ability to provide a continuous lining for the drying chamber and the product separator or section thereof of the support structure or to provide the product separator or section thereof for attachment to the frame of the support structure, and the ability to maintain the integrity of the walls during the spray-drying process (while supported by the support structure), such that the components of the spray-drying process do not escape the container through the walls. In particular, the walls need to be impermeable to the liquid feed and the spray-dried product under the process conditions that are to be applied during the spray drying procedure. They also need to be impermeable to the impurities I contaminants (e.g., microorganisms) from the outside environment. In embodiments where the assembly is sterilized before use, it is necessary that the container walls (like all other parts of the assembly) are able to withstand the sterilization process. As described above, it must also be possible for the container to be attached either directly or indirectly to the gas distributor, the atomizer and the outlet part(s) in a manner that again prevents the escape of the components of the spray-drying process, and the ingress of contaminants such as microorganisms.

[0076] The container may be made from synthetic or natural materials such metallic materials and polymeric materials including plastic or rubber. In particular, the flexible portions of the container walls may be made from polymeric material. Suitable examples are flexible pharmaceutical grade materials (e.g., LDPE, polypropylene (PP) or polyamide (PA) having a typical thickness of between 50 to 350 pm (more typically 50.8 to 305 pm representing 2 to 12 mil (British Imperial)), or semi-rigid I rigid pharmaceutical grade materials e.g., HDPE, or a mix between the two. Such materials are particularly suitable where the assembly is for single use. (It is noted that some of these materials may be slightly permeable to gases e.g., water vapour, and atmospheric gases such as oxygen, carbon dioxide and nitrogen, but this does not prevent their use in the invention since they are sufficiently impermeable to prevent any of the components of the spray-drying process from escaping from the assembly and / or to avoid contaminants, e.g., microorganisms, from the outside environment affecting the aseptic environment inside the assembly.)

[0077] The non-flexible portions of the container walls may be used to provide support to the flexible portions. Suitable examples are rigid plastic and stainless steel. As indicated above, the choice of material will be impacted by the range of process variables for the intended spray drying method and possible sterilization method. For example, whereas it is recommended that polymeric materials are kept below 100°C, metallic materials can go beyond 250°C.

[0078] The product separator part may comprise a bag (e.g., as shown as part (36) in Figure 1 ) which is arranged to receive the spray-dried product from the product separator during the spray drying. In some examples, the bag may be formed as an extension of one or more flexible portions of the container walls defining the product separator part.

[0079] The container may further comprise a connecting conduit (e.g., as shown as part (37) in Figure 1 ), which connects the chamber part of the container to the product separator part. The connecting conduit may be positioned on a section of the chamber part that is configured to line a side wall of the spray drying chamber (2a, 2b) of the support structure (39), i.e. , a wall that is not diametrically opposite the atomizer. For example, as shown in Figure 1 , the connecting conduit (37) is positioned on one side of the chamber part that is not directly opposite the atomizer (22). In this embodiment, once the assembly is installed on the support structure to form a spray drying apparatus, and the spray drying apparatus is in use in the method of spray drying of the invention, the spray dried powder produced in the spray drying chamber is collected from the side of the spray drying chamber. This arrangement is preferred where the product separator is a cyclone.

[0080] In one preferred example, the one or more container walls that define the chamber part and the product separator part, and optionally also the connecting conduit, are formed from a single flexible portion.

[0081] In another preferred example, the one or more container walls that define the chamber part, and optionally also the connecting conduit, are formed from a single flexible portion, while the one or more container walls that define the product separator part, which is a product separator e.g., a cyclone, are rigid. The one or more container walls may comprise a single layer or may comprise two or more layers. In particular, where the liquid feed comprises a highly potent or toxic product, e.g., in highly potent API processing (HPAPI), two or more layers may be necessary in order to ensure a suitable level of redundancy in the containment measures. Additional or alternative containment measures that may be necessary for such products include fixing the flexible portions of the container walls to allow negative pressure (e.g., temporary fixtures such as fixings made from double-sided adhesives or straps that can be tied together at multiple discrete points) or using equipment within a glovebox (e.g., which provides a second level of containment for the assembly) or equipment with double walls.

[0082] As mentioned above, the assembly of the invention may comprise isolation devices and in particular the assembly may comprise a plurality of isolation devices (e.g., as shown as parts (7), (8), (9), (10) in Figure 1 ). At least one of these is positioned on at least one of the one or more inlet conduits, and at least one other of the these is positioned on at least one of the one or more outlet conduits. In other words, the assembly may comprise at least one isolation device positioned on one of the inlet conduits and at least one isolation device positioned on one of the outlet conduits. In one example, there is an isolation device positioned on the first inlet conduit (e.g., as shown as part (7) in Figure 1 ) and another isolation device positioned on the first outlet conduit (e.g., as shown as part (10) in Figure 1 ), such that both the drying gas coming into the assembly and the exhaust gas leaving the assembly during spray drying pass through an isolation device on their way into I out of the assembly.

[0083] In another example, there is at least one isolation device positioned on each of the one or more inlet conduits and / or on each of the one or more outlet conduits. Preferably, and in particular where the assembly is for use in a spray drying method where sterility is required, there is at least one isolation device positioned on each of the one or more inlet conduits and at least on the first outlet conduit, more preferably on each of the one or more outlet conduits.

[0084] As described above, the inlet and outlet conduits may be defined as having a distal part and a proximal part. Accordingly, the isolation device may be positioned on the distal part of each of the one or more inlet conduits and on the distal part of each of the one or more outlet conduits.

[0085] The isolation devices are to prevent contaminants from entering the assembly and / or to prevent the spray dried product escaping from the assembly during spray drying. In particular where the assembly is for use in a process of spray drying where sterility is required, the isolation devices prevent contaminants, e.g., microorganisms, from entering the assembly. Where the assembly is for use in a process of spray drying a potent product, the isolation devices prevent the spray dried product from (inadvertently) escaping from the assembly.

[0086] The plurality of isolation devices enable entry into and exit from the assembly to be controlled such that the internal environment of the assembly, between one or more inlet conduits and the one or more outlet conduits, can be controlled, e.g., the internal environment can be isolated from the external environment of the assembly.

[0087] These isolation devices can be used to ensure that all inner surfaces of the assembly (e.g., as marked as (32), (33), and (34) in Figure 3) that contact e.g., the drying gas, atomizing gas, feed reactants, liquid feed, spray-dried product etc., during spray drying are isolated from the outside environment of the assembly. In particular, the isolation devices are capable of isolating these inner surfaces from the outside environment by preventing contaminants from entering the assembly and / or by preventing the spray dried product escaping. For example, the plurality of isolation devices may enable these inner surfaces to be isolated from the outside environment of the assembly in a filtered, sterile filtered, or airtight manner.

[0088] The isolation devices may be filters or valves. In particular, the filters may be sterile filters. The valves may be airtight valves. The valves may be split-butterfly valve. In some examples, valves such as split-butterfly valves that are designed for local sterilization, i.e., sterilization at the interface between the inlet / outlet conduit and the external environment of the assembly, can be used. Preferably the plurality of isolation devices is a plurality of sterile filters. However, where the assembly comprises a second outlet conduit for removing the spray dried product from the assembly, the second outlet conduit may comprise a splitbutterfly valve as the isolation device.

[0089] In particular, the isolation device positioned on the first inlet conduit, which is used for supplying the drying gas to the gas distributor, may comprise an insulating layer to reduce or eliminate heat loss from the drying gas as it passes through the isolation device. It is noted that the isolation device may be made of polymeric materials, which are suitable for sterilization by gamma irradiation, but which have limitations in the temperatures that they can withstand. Therefore, it may be necessary to avoid heat loss from the gas as it passes through the isolation device as far as possible and ensure that the inlet and outlet temperature of the gas are comparable.

[0090] For example, as shown in Fig. 8, the isolation device (7) may be filter comprising an insulating layer (45) that is an external zone, without any contact to the process, through which a heated fluid (44) can be passed. The device comprises an inlet (40) and outlet (41 ) for the heated fluid, and a separate inlet (42) and outlet (43) for the drying gas.

[0091] In addition, or alternatively, also to reduce heat losses, the isolation device for the drying gas can be part of the gas distributor. For example, as shown in Fig.

[0092] 9, the isolation device (7) can be a filter which is embedded in the gas distributor (1 ). This embodiment, in which the isolation device for the drying gas and the gas distributor are manufactured as one part for use in the assembly, has the additional advantage of reducing the overall number of parts in the assembly.

[0093] In a similar manner, the isolation device for the first outlet conduit, which is for conducting the outlet gas away from the spray drying apparatus, may be manufactured as one part with the first outlet conduit. Similarly, where the product separator part of the container is a product separator, e.g., a cyclone, or upper section thereof, e.g., cyclone barrel, the product separator part, first outlet conduit, and isolation device therefor, can be manufactured as a single part (e.g., a subassembly) in order to increase the compaction of the assembly, and also to reduce heat loss.

[0094] The isolation devices can advantageously be used: (i) to supply the assembly in a pre-sterilized form, and therefore no in situ sterilization of the assembly is necessary. The assembly can be provided pre-sterilized and with the isolation devices in place to ensure the inner surfaces of the assembly that will contact the spray drying components will remain sterile. In this case the isolation devices can comprise sterile filters or closed values which act to isolate the inner surfaces from the non-sterile exterior environment. Suitable sterile filters may be also be 0.2 or 0.1 pm sterile filters; (ii) to enable the rest of the equipment involved in the spray drying to be quickly re-used - since all inputs and exits from the assembly involve an isolation device, the spray-dried product of the spray drying will not reach the rest of the spray drying apparatus, e.g. gas sources, gas exhaust, further conduits, etc., and therefore once the assembly has been removed from the support structure, no time-consuming cleaning or sterilization is required before re-use; and (iii) to contain potent or toxic liquid feeds or products. In particular, the isolation devices can be used to prevent such components leaving the assembly. This enhances the safety of the spray drying of such components and also avoids the need for the additional cleaning requirements that are necessary with such products.

[0095] For (ii) and (iii) it may be sufficient to use suitable filters rather than sterile filters. Suitable filters can be filters would also be 0.2 or 0.1 pm but would not need to be sterile qualified.

[0096] The description of the inventions provided herein refer to “sterile filter” when referring to a part connected to the inlet and outlet conduits. It should be understood a sterile filter is a part which allows flow of liquids or gas but does not allow the ingress of contaminants such as microorganisms, and is not a part that is sterile prior to assembly of the invention.

[0097] In view of (i) above, the assembly of the invention may be one that has been sterilized such that the inner surfaces of the assembly that are to contact the components of the spray drying process are sterile, i.e., the internal environment of the assembly between the one or more inlet conduits and the one or more outlet conduits is sterile. Suitable sterilization methods are described below.

[0098] Once the assembly has been sterilized, the sterility can be maintained by the isolation devices such as sterile filters and / or airtight valves in a closed position. However, the assembly may also be provided in an airtight or hermetically sealed sterile package.

[0099] As highlighted above, it is important that the parts of the assembly are joined I connected with sealants or equivalent to ensure that all joins are hermetic / airtight, or at least are sufficient to prevent microorganisms from permeating the assembly. This ensures maintenance of sterility post-sterilization.

[0100] In the assembly of the present invention of the present invention the chamber part of the container is suitable for lining a spray drying chamber of the support structure that is (i.e., is sized / has a footprint of) in the range of 0.5 m by 0.5 m by 0.2 m to 3.5 m by 3.5 m by 1.5 m, preferably about 1 m by about 1 m by about 0.2 m to about 3 m by about 3 m by about 0.5 m (where the term “about” means ± 10%, more preferably ± 5%). In the spray drying apparatus of the invention, further discussed below, the apparatus may have a spray drying chamber of this size.

[0101] Alternatively, or in addition, the chamber part of the container of the assembly may be suitable for lining a spray drying chamber that is to operate with a drying gas mass flow rate of 30 kg / hr to 450 kg / hr, preferably 35 kg / hr ± 10% to 400 kg / hr ± 10%, more preferably 35 kg / hr ± 5% to 400 kg / hr ± 5%. In the method of spray drying of the invention, further discussed below, the method may comprise supplying a drying gas to the spray drying chamber at this mass flow rate.

[0102] In a further aspect the invention provides a method of producing an assembly as described above, the method comprising connecting the container directly or indirectly to the gas distributor, the atomizer, and the outlet part, to produce the assembly. The one or more inlet conduits and the one or more outlet conduits can already be connected to the gas distributor I atomizer I outlet part, etc., or they can be connected to these after the gas distributor I atomizer I outlet part have been connected to the container.

[0103] The method may comprise sterilizing the assembly. In particular, the assembly can be sterilized in an autoclave or via gamma irradiation. However, other suitable sterilization methods, such as chemical treatment, can also be used.

[0104] The method may comprise packaging the assembly into a package. This can be done prior to sterilization, and the packaged assembly can be sterilized, to produce a sterile package. The package once sealed is impermeable to microorganisms, so the sterility of the package can be maintained through storage and transportation and installation into the support structure.

[0105] In a still further aspect, the present invention provides a process for producing a spray drying apparatus in which the assembly as described herein (e.g., as shown as part (38) in Figure 5) is installed into a support structure (e.g. as shown as part (39) in Figure 5). The support structure comprises a spray drying chamber (e.g., as shown as parts (2a) and (2b) in Figure 4) and a product separator (e.g., as shown as part (35a, 35b) in Figure 4) or a section thereof, or a frame therefor (e.g., as shown as parts 47a, 47b, 47c, 47d, in Figure 11 ). The process comprises:

[0106] - connecting the gas distributor and the atomizer directly or indirectly to the spray drying chamber;

[0107] - connecting the outlet part directly or indirectly to the product separator or section thereof or frame therefor;

[0108] - fitting the chamber part of the container into the spray drying chamber; and

[0109] - fitting the product separator part into the product separator or section thereof, or attaching the product separator part to the frame.

[0110] The process steps may be performed in any order. However, preferably the connecting steps are performed before the fitting steps. Where the one or more container walls comprise one or more flexible portions, the fitting steps may require inflation of the assembly from the collapsed form. As indicated above, the container is a component with a chamber part and a product separator part and, once fitted, provide a continuous lining to the spray drying chamber and product separator or section thereof of the support structure (at least in the embodiments where the support structure comprises the product separator or section thereof).

[0111] In one example of inflation, the fitting step comprises blowing gas into the chamber part and the product separator part through the gas distributor. This can occur prior to the start of spray drying, or at the very beginning of the spray drying process.

[0112] The fitting step may comprise securing the outside of the chamber part to the inside of the spray drying chamber and / or securing the outside of the product separator part to the inside of the product separator or section thereof. The fitting step may also comprise securing / attaching the product separator part to the product separator frame of the support structure. Temporary fixtures such as fixings made from double-sided adhesives or straps that can be tied together at multiple discrete points can be used. These types of fixtures can be used when the assembly is for spray-drying of a potent product, where it may be required as a safety feature to operate the spray-drying process with a negative pressure in the chamber.

[0113] An example of a spray drying apparatus prepared according to the process of the invention is shown in Figures 3 and 4.

[0114] The process may further comprise:

[0115] - connecting the first inlet conduit to a liquid feed source;

[0116] - connecting the first inlet conduit to a drying gas source; and

[0117] - connecting the first outlet conduit to a gas exhaust unit or to a gas recycling unit; and optionally, where the atomizer of the assembly comprises a two-fluid nozzle, - connecting the third inlet conduit to an atomizing gas source.

[0118] The process may further comprise one or more of:

[0119] - connecting the second inlet conduit to a liquid feed source; or

[0120] - connecting the one or more feed reactor inlet conduits to one or more reactant sources.

[0121] The process may also further comprise:

[0122] - connecting the second outlet conduit to a product collection part.

[0123] The support structure may comprise one or more fixings or clamps (e.g., as shown by parts 11 , 12, 13, 14, 15, 16, 17, 18, and 19 in Figures 3 and 4) for securing the support structure after the assembly has been inserted.

[0124] The present invention further provides for a spray drying apparatus comprising as assembly as described herein installed into a support structure comprising a spray drying chamber and a product separator or section thereof, or frame therefor. In particular, the spray drying apparatus can be produced by the method described above.

[0125] The present invention further provides a method of spray drying comprising using the spray drying apparatus to produce a spray dried product. In particular, once the assembly is installed into the support structure and the inlet and outlet conduits connected, the apparatus can be operated according to established spray-drying protocols. In some examples where the assembly comprises a feed reactor, the method may comprise producing the liquid feed for the atomizer in the feed reactor of the assembly.

[0126] Once the spray drying has been completed, the assembly can be uninstalled from the support structure, and the support structure reused by installing a second assembly according to the invention. In particular, it is preferred that the assembly of the invention is a single-use assembly. Once the spray-dried product has been collected from the product separator part of the container, the remainder of the assembly can be disposed of. However, the used assembly may be cleaned and re-sterilized offline and then reused.

[0127] LIST OF REFERENCE NUMERALS USED IN THE FIGURES

[0128] I - Gas distributor (with imbedded nozzle)

[0129] 2a - Spray drying chamber of the support structure

[0130] 2b - Spray drying chamber of the support structure

[0131] 3 - Chamber part of container

[0132] 4 - Bottom cone of the spray drying chamber of the support structure

[0133] 5 - First outlet conduit

[0134] 6 - Support wall for bag of product separator part

[0135] 7 - Isolation device for first inlet conduit (drying gas inlet)

[0136] 8 - Isolation device for third inlet conduit (atomization gas inlet)

[0137] 9 - Isolation device for second inlet conduit (liquid feed inlet)

[0138] 10 - Isolation device for first outlet conduit (drying gas outlet)

[0139] I I to 19 - Fixings (e.g., connection clamps)

[0140] 20 - Nozzle tip of atomizer

[0141] 21 - Nozzle cap of atomizer

[0142] 22 - Atomizer

[0143] 23 - Second inlet conduit (for supplying the liquid feed to the atomizer)

[0144] 24 - First inlet conduit (for supplying the drying gas to the gas distributer)

[0145] 25 - Third inlet conduit (for supplying the atomizing gas to the atomizer)

[0146] 26 - Outlet part

[0147] 27 - Container

[0148] 28, 29, 30 - Container wall

[0149] 31 - Product separator part of container

[0150] 32, 33, 34 - Inner surfaces of the assembly

[0151] 35a - Product separator of the support structure

[0152] 35b - Product separator of the support structure

[0153] 36 - Bag for collecting spray-dried product

[0154] 37 - Connecting conduit

[0155] 38 - Assembly - Support structure - Inlet for heated fluid (part of isolation device 7) - Outlet for heated fluid (part of isolation device 7) - Inlet for drying gas (part of isolation device 7) - Outlet for drying gas (part of isolation device 7) - Heated fluid - Insulating layer - Heat shield (part of gas distributor 1 ) a - Frame for product separator b - Frame for product separator c - Frame for product separator d - Frame for product separator

Claims

CLAIMS1 . An assembly (38) for installation into a support structure (39) comprising a spray drying chamber (2a, 2b) and a product separator (35a, 35b) or a section thereof, or a frame therefor (47a, 47b, 47c, 47d), to form a spray drying apparatus for producing a spray-dried product and an outlet gas using a liquid feed and a drying gas, the assembly comprising:- a gas distributor (1 ) and an atomizer (22), the gas distributor and the atomizer being for attachment to the spray drying chamber (2a, 2b) of the support structure;- one or more inlet conduits (23, 24, 25) comprising a first inlet conduit (24) for supplying the drying gas to the gas distributor;- an outlet part (26) for attachment to the product separator or section thereof or frame therefor of the support structure;- one or more outlet conduits (5) comprising a first outlet conduit comprised in the outlet part for conducting the outlet gas away from the spray drying apparatus; and- a container (27) arranged between the gas distributor, the atomizer, and the outlet part and connected directly or indirectly thereto, the container comprising one or more container walls (28, 29) that define at least a chamber part (3) and a product separator part (31 ), wherein the chamber part is for lining the spray drying chamber of the support structure and the product separator part is for lining the product separator or section thereof of the support structure, or for attachment to the frame of the support structure.

2. The assembly according to claim 1 , wherein the one or more inlet conduits comprise a second inlet conduit (23) for supplying the liquid feed to the atomizer (22).

3. The assembly according to claim 1 , wherein the assembly comprises a feed reactor and a feed conduit for delivering feed from the feed reactor to the atomizer (22).

4. The assembly according to claim 3, wherein the one or more inlet conduits comprises one or more feed reactor inlet conduits for supplying reactants to the feed reactor.

5. The assembly according to any preceding claim, wherein the one or more inlet conduits comprises a third inlet conduit (25) for supplying an atomizing gas to the atomizer (22).

6. The assembly according to any preceding claim, wherein the one or more outlet conduits comprises a second outlet conduit for removing the spray dried product from the assembly.

7. The assembly according to any preceding claim, comprising a plurality of isolation devices (7, 8, 9, 10), wherein at least one of the plurality of isolation devices is positioned on at least one of the one or more inlet conduits (23, 24, 25) and at least one other of the plurality of isolation devices is positioned on at least one of the one or more outlet conduits (5), wherein the plurality of isolation devices are to prevent contaminants from entering the assembly and / or to prevent the spray dried product escaping from the assembly during spray-drying.

8. The assembly according to claim 7, wherein at least one of the plurality of isolation devices (7, 8, 9, 10) is positioned on each of the one or more inlet conduits (23, 24, 25) and on each of the one or more outlet conduits (5).

9. The assembly according to claim 7 or claim 8, wherein the plurality of isolation devices (7, 8, 9, 10) are capable of isolating the internal environment of the assembly from the external environment.

10. The assembly according to any of claims 7 to 9, wherein the at least one isolation device is independently selected from a filter, or a valve.

11. The assembly according to claim 10, wherein the filter is a sterile filter and / or wherein the valve is a split-butterfly valve.

12. The assembly according to any of claims 7 to 11 , wherein the plurality of isolation devices comprises an isolation device (7) positioned on the first inlet conduit (24), which isolation device comprises an insulating layer (45) to reduce heat loss from the drying gas.

13. The assembly according to claim 12, wherein the insulating layer (45) comprises an envelope for the isolation device (7) for circulating a heated fluid (44) around the device.

14. The assembly according to any of claims 7 to 13, wherein the plurality of isolation devices comprises an isolation device (7) positioned on the first inlet conduit (24), which isolation device is part of the gas distributor (1 ).

15. The assembly according to any of claims 7 to 14, wherein the plurality of isolation devices (7, 8, 9, 10) comprises a plurality of filters, optionally a plurality of sterile filters.

16. The assembly according to any preceding claim, wherein the assembly has been sterilized such that the internal environment of the assembly is sterile.

17. The assembly according to any preceding claim, wherein the support structure comprises the product separator, and the product separator (35a, 35b) is a cyclone or an electrostatic separator.

18. The assembly according to claim 17, wherein the product separator (35a, 35b) is a cyclone.

19. The assembly according to any of claims 1 to 16, wherein the support structure comprises a frame (47a, 47b, 47c, 47d) for the product separator and wherein the product separator part (31 ) of the container comprises the product separator for attachment to the frame.

20. The assembly according to claim 19, wherein the product separator is a cyclone.

21. The assembly according to any of claims 1 to 16, wherein the support structure comprises: (a) a frame for a first section of the product separator; and (b) a second section of the product separator, and wherein the product separator part of the container comprises: (c) the first section of the product separator for attachment to (a); and (d) a segment for lining (b).

22. The assembly according to claim 21 wherein the one or more container walls that define (c) of the product separator part are rigid and the one or more container walls that define (d) of the product separator part are flexible.

23. The assembly according to claim 21 or claim 22, wherein the product separator is a cyclone and the first section is a cyclone barrel and the second section is a cyclone cone.

24. The assembly according to any preceding claim, wherein the container (27) comprises a connecting conduit (37) connecting the chamber part (3) to the product separator part (31 ), optionally wherein the connecting conduit is positioned on a section of the chamber part that is configured to line a side wall of the spray drying chamber (2a, 2b) of the support structure (39).

25. The assembly according to any preceding claim, wherein the one or more container walls comprise one or more flexible portions.

26. The assembly according to claim 25, wherein the one or more flexible portions are formed of a polymeric material.

27. The assembly according to claim 25 or claim 26, wherein the one or more flexible portions enable the assembly to exist in at least two arrangements, the at least two arrangements comprising an installed form as installed on the support structure and a collapsed form in which the dimensions of the container (27) are reduced as compared to the installed form.

28. The assembly according to claim 27, wherein at least a part of the container (27) is in the collapsed form.

29. The assembly according to any of claims 25 to 28, wherein the product separator part (31 ) comprises a bag (36) for collecting the spray-dried product.

30. The assembly according to claim 29, wherein the bag (36) is formed as an extension of the one or more flexible portions of the container walls defining the product separator part (31 ).31 . The assembly according to any of claims 25 to 30, wherein the one or more container walls that define the chamber part (3), the product separator part (31 ), and optionally the connecting conduit (39), comprise a single flexible portion.

32. The assembly according to any preceding claim, wherein the atomizer (22) is connected to or is part of the gas distributor (1 ).

33. The assembly according to any preceding claim, wherein the gas distributor (1 ) and atomizer (22) are formed as a single unit.

34. The assembly according to claim 33, wherein the gas distributor (1 ), the atomizer (22), the first inlet conduit (23), and optionally the second inlet conduit (24) are formed as a single unit.

35. The assembly according to any preceding claim, wherein the assembly comprises a heat shield (46) connected to the gas distributor (1 ) to protect the chamber part (3) of the container from heat from the drying gas entering the spray drying chamber from the gas distributor.

36. The assembly according to any preceding claim, wherein the chamber part (3) of the container is sealed to the gas distributor (1 ) and the atomizer (22), or wherein the chamber part is sealed to the heat shield of claim 35.

37. The assembly according to any preceding claim, wherein the product separator part (31 ) is sealed to the outlet part (26).

38. The assembly according to any preceding claim, wherein the assembly comprises one or more fixings (14, 15, 17, 18, 19) for fixing the assembly to the support structure.

39. The assembly according to any preceding claim, wherein the one or more container walls are formed of a single layer or are formed of two or more layers.

40. The assembly according to any preceding claim, which is provided in a sterile package.

41. A method of producing an assembly (38) according to any of claims 1 to 40, the method comprising connecting the container (27) directly or indirectly to the gas distributor (1 ), the atomizer (22) and the outlet part (26), to produce the assembly.

42. The method according to claim 41 , comprising sterilizing the assembly.

43. The method according to claim 42, comprising sterilizing the assembly with gamma irradiation or in an autoclave.

44. The method according to any of claims 41 to claim 43, comprising packaging the assembly.

45. A process for producing a spray drying apparatus, the process comprising installing an assembly (38) according to any of claims 1 to 41 into a support structure (39) comprising a spray drying chamber (2a, 2b) and a product separator (35a, 35b) or section thereof, or frame (47a, 47b, 47c, 47d) therefor, wherein the process comprises:- connecting the gas distributor (1 ) and the atomizer (22) directly or indirectly to the spray drying chamber (2a, 2b);- connecting the outlet part (26) directly or indirectly to the product separator (35a, 35b) or section thereof, or frame therefor;- fitting the chamber part (3) of the container into the spray drying chamber (2a, 2b); and- fitting the product separator part (31 ) into the product separator (35a, 35b) or section thereof, or attaching the product separator part to the frame.

46. The process according to claim 45, comprising:- connecting the first inlet conduit (24) to a drying gas source; and- connecting the first outlet conduit (5) to a gas exhaust unit or to a gas recycling unit.

47. The process according to claim 45 or claim 46, comprising:- connecting the second inlet conduit (23) to a liquid feed source; or- connecting the one or more feed reactor inlet conduits to one or more reactant sources.

48. The process according to any of claims 45 to 47, comprising:- connecting the second outlet conduit to a product collection part.

49. The process according to any of claims 45 to 48, comprising:- connecting the third inlet conduit (25) to an atomizing gas source.

50. The process according to any one of claims 45 to 49, wherein fitting the chamber part (3) into the spray-drying chamber (2a, 2b) and / or fitting the product separator part (31 ) into the product separator (35a, 35b) or section thereof comprises inflating the chamber part and / or the product separator part such that they form a lining for the spray drying chamber and / or the product separator or section thereof, respectively.51 . The process according to any one of claims 45 to 50, comprising securing the chamber part (3) to the spray drying chamber (2a, 2b) and securing theproduct separator part (31 ) to the product separator (35a, 35b) or section thereof, or to the frame.

52. A spray drying apparatus comprising an assembly (38) according to any of claims 1 to 40 installed into a support structure (39) comprising a spray drying chamber (2a, 2b) and a product separator (35a, 35b), or section thereof, or frame (47a, 47b, 47c, 47d) therefor.

53. The spray drying apparatus according to claim 52, wherein the spray drying apparatus is produced by the process of any one of claims 45 to 51 .

54. A method of spray drying comprising using a spray drying apparatus according to claim 52 or claim 53 to produce the spray-dried product and the outlet gas from the liquid feed and the drying gas.

55. A method of reusing the spray drying apparatus used in the method of claim 54, the method comprising uninstalling the assembly (38) after use of the spray drying apparatus, and installing a further assembly according to any of claims 1 to 40 into the support structure.