GB2551652A

GB2551652A - Dispensing system

Info

Publication number: GB2551652A
Application number: GB1710041.3A
Authority: GB
Inventors: Black Edward
Original assignee: Eco-Genics Ltd
Current assignee: Eco-Genics Ltd
Priority date: 2016-06-24
Filing date: 2017-06-23
Publication date: 2017-12-27
Anticipated expiration: 2037-06-23
Also published as: GB2551652B; GB201710041D0; GB201611060D0

Abstract

An apparatus for the distribution of a solid, ideally dry ice, into a pressurised fluid stream, wherein the solid becomes pressurised prior to distribution into the stream. The apparatus comprises a first body 110, a second body 130, a hopper at a first pressure and a pressurised outlet channel 160 at a second pressure wherein the second pressure is greater than the first pressure. The first body comprises a first surface with at least two chambers 121,122 extending therefrom, defining an interior space. The first surface is proximal to a surface of the second body and rotates relative to that surface. The second body comprises one or more surfaces including two pressure equilibrium openings in fluid communication with each other 151, 152, a first port 140 and a second port 150. The chambers form a closed body when aligned with a part of second body surfaces not comprising a port or opening. When a chamber is aligned with the first port, the chamber has a first pressure and solids are transferred from the hopper to the chamber via the first port. When a chamber is aligned with the second port, the chamber has a second pressure and solids are transferred from the chamber to the pressurised outlet channel and into the pressurised fluid stream. When two chambers are aligned with the pressure equilibrium openings, pressure is transferred between the chambers so that it is equilibrated. A method of distributing solid into a pressurised fluid stream is also disclosed.

Description

DISPENSING SYSTEM

The present invention relates to a method and apparatus for dispensing an unpressurised solid into a pressurised fluid stream.

BACKGROUND TO THE INVENTION

Dry ice changes between a solid and a gas with no intervening liquid phase. This makes its behaviour difficult to predict and control. During sublimation, dry ice pellets can be seen to move around on a solid surface, or even to hover slightly over a solid surface.

Known apparatus for dispensing unpressurised solid, such as dry ice, into a pressurised fluid stream generally involve pressurising the solid only upon transfer into the fluid stream. The dispenser is generally open to the surrounding atmosphere meaning that moisture from air can contact the dry ice causing frosting on the machinery. This can cause the machinery to freeze up. As the dispenser is unpressurised, any pressure from the pressurised stream which is transferred to the solid housing is lost, increasing the inefficiency of the system.

STATEMENT OF INVENTION

According to an aspect of the present invention, there is provided an apparatus for the distribution of a solid into a pressurised fluid stream comprising: a first body and a second body, wherein the first body includes a first surface, provided proximal to a surface of the second body and the first surface is rotatable relative to the surface of the second body; wherein the first body comprises at least two chambers extending from the first surface, each chamber defining an interior space wherein; one or more surface(s) of the second body includes a first port, a second port and two pressure equilibration openings in fluid communication with each other, one of the pressure equilibration openings being disposed one side of an axis which bisects the first and second ports, and the other of the pressure equilibration openings being disposed on the other side of the axis, wherein each chamber together with the one or more surfaces of the second body forms a closed body unless the chamber is aligned with a port or opening in the one or more surfaces of the second body; a hopper at a first pressure, leading to the first port said hopper suitable for housing the solid, wherein the first port allows access between the hopper and the interior of one of the chambers where the chamber is aligned with the first port, and alignment of one of the chambers and the first port allows transfer of the solid from the hopper to the chamber; a pressurised outlet channel at a second pressure leading from the second port to the pressurised fluid stream, wherein the second pressure is greater than the first pressure, and wherein the second port allows access between the pressurised outlet channel and the interior of one of the chambers where the chamber is aligned with the second port, and alignment of one of the chambers and the second port allows transfer of the solid from the chamber to the pressurised outlet channel and into the pressurised fluid stream wherein, where one of the chambers is aligned with one of the pressure equilibration openings, and another of the chambers is aligned with the other of the pressure equilibration openings, the two chambers are in fluid communication with each other and the pressure between the two chambers is equilibrated.

According to one aspect of the present invention, there is provided a device for the distribution of a solid into a pressurised fluid stream downstream from the pressurised outlet channel. The device may comprise: a dispenser suitable for dispensing the solid from the pressurised outlet channel into the pressurised fluid stream (generally in a metered amount), wherein the pressurised fluid stream flows through the dispenser, from one side of the dispenser to another side of the dispenser; wherein the dispenser comprises more than one housing for the solid, each housing extending from one side of the dispenser to the other side of the dispenser, a third port, providing access between the pressurised outlet channel and a housing of the dispenser where the housing is aligned with the third port, allowing transfer of the solid from the pressurised outlet channel to the housing, wherein the dispenser is movable between a position where a housing is aligned with the third port, and a position in which the housing is aligned with the fluid stream, and the fluid stream flows through the housing; wherein the device is at a pressure of from 80 to 120% of the pressure of the pressurised fluid stream.

According to a further aspect of the present invention there is provided a method of distributing a solid into a pressurised fluid stream comprising: providing the apparatus as described herein, aligning a first chamber with the first port, and transferring solid from the hopper to the first chamber, aligning a second chamber with the second port, and thus allowing access between the pressurised outlet channel and the interior of the second chamber causing the pressure within the second chamber to increase, rotating the first surface of the first body relative to the surface of the second body to bring the first chamber into alignment with one of the pressure equilibration openings, and to bring the second chamber into alignment with the other of the pressure equilibration openings and thus equilibrating the pressure between the first and second chambers, rotating the first surface of the first body relative to the surface of the second body to bring the first chamber into alignment with the second port and thus allowing access between the pressurised outlet channel and the interior of the first chamber causing the pressure within the first chamber to increase, and solid from the first chamber to be transferred to the pressurised outlet channel, rotating the first surface of the first body relative to the surface of the second body to bring the second chamber into alignment with the first port, and transferring solid from the hopper to the second body, rotating the first surface of the first body relative to the surface of the second body to bring the first chamber into alignment with one of the pressure equilibration openings, and to bring the second chamber into alignment with the other of the pressure equilibration openings and thus equilibrating the pressure between the first and second chambers, rotating the first surface of the first body relative to the surface of the second body to bring the first chamber into alignment with the first port, wherein the solid is dispensed from the pressurised outlet channel, to a dispenser and into the pressurised fluid stream.

According to a further aspect of the present invention there is provided a method of distributing a solid into a pressurised fluid stream comprising: providing the device as described herein, transferring solid from the pressurised outlet channel, through the third port into a housing of the dispenser, moving the dispenser into a position in which the housing is aligned with the fluid stream, wherein the flow of the pressurised fluid stream displaces the solid from the housing into the fluid stream.

According to a further aspect of the invention there is provided a method of dispensing solid carbon dioxide (dry ice) into a pressurised air stream comprising the steps of one or both of the methods provided above.

There is also provided a method of cleaning apparatus including contact the apparatus with the pressurised air stream to which the solid carbon dioxide has been dispensed, wherein the concentration of solid carbon dioxide (dry ice) in the air stream is substantially constant. Fluctuations in concentration are generally less than 10%, typically less than 5%, suitably 1% or less.

There is also provided a method of preserving perishable items (such as food stuff) including contact the perishable items with the pressurised air stream to which the solid carbon dioxide has been dispensed, wherein the concentration of solid carbon dioxide (dry ice) in the air stream is substantially constant. Fluctuations in concentration are generally less than 10%, typically less than 5%, suitably 1% or less.

According to a further embodiment, there is provided a system for performing the methods disclosed herein. The system can include the apparatus and/or the device as disclosed herein for dispensing the solid into a pressurized fluid stream, and generally an analytical instrument used to measure the amount of solid dispensed, and the rate of dispensation. Generally, the system includes the apparatus and the device disclosed herein. The system also can include a suitably programmed computer for carrying out one or more steps of the methods. For example, the suitably programmed computer can carry out or assist in one or more of control of the speed of rotation of the drum, pressurization of part of the apparatus/device, control of the speed of movement of the dispenser, measuring the concentration of solid in the fluid stream, measuring any fluctuations in the concentration of the solid in the fluid stream, and equivalents thereof.

According to a further embodiment there is provided a kit of parts comprising an apparatus for dispensing a solid in a pressurised fluid stream as described herein, and instructions for use.

According to a further embodiment there is provided a kit of parts comprising a device for dispensing a solid in a pressurised fluid stream as described herein, and instructions for use. The kit optionally comprises more than one removable dispenser wherein each dispenser includes housings having a different capacity.

DEFINITIONS

The term “proximal” is generally used herein to refer to 2 mm or less in distance. According to one embodiment, where two surfaces are proximal to each other, they may be touching. Two proximal surfaces may be biased against each other.

In the context of the present application, the term “a seal” is used to refer to a tight or complete closure.

Throughout the application, where apparatus or devices are described as having, including, or comprising specific components, or where processes or methods are described as having, including, or comprising specific process steps, it is contemplated that apparatus/devices of the present teachings also consist essentially of, or consist of, the recited components, and that the processes/methods of the present teachings also consist essentially of, or consist of, the recited process steps.

In the application, where an element or component is said to be included in and/or selected from a list of recited elements or components, it should be understood that the element or component can be any one of the recited elements or components, or the element or component can be selected from a group consisting of two or more of the recited elements or components. Further, it should be understood that elements and/or features of an apparatus, a device, a method or a process described herein can be combined in a variety of ways without departing from the spirit and scope of the present teachings, whether explicit or implicit herein.

The use of the terms “include,” “includes”, “including,” “have,” “has,” or “having” should be generally understood as open-ended and non-limiting unless specifically stated otherwise.

The use of the singular herein includes the plural (and vice versa) unless specifically stated otherwise. In addition, where the use of the term “about” is before a quantitative value, the present teachings also include the specific quantitative value itself, unless specifically stated otherwise. As used herein, the term “about” refers to a ±10% variation from the nominal value unless otherwise indicated or inferred.

All numerical values provided incorporate 10% less than and 10% more than the numerical value provided.

It should be understood that the order of steps or order for performing certain actions is immaterial so long as the present teachings remain operable. Moreover, two or more steps or actions may be conducted simultaneously.

Features, integers, characteristics, described in conjunction with a particular aspect, embodiment or example of the invention are to be understood to be applicable to any other aspect, embodiment or example described herein unless incompatible therewith.

DETAILED DESCRIPTION

According to an aspect of the present invention, there is provided an apparatus for the distribution of a solid into a pressurised fluid stream comprising: a first body and a second body, wherein the first body includes a first surface, provided proximal to a surface of the second body and the first surface is rotatable relative to the surface of the second body; wherein the first body comprises at least two chambers extending from the first surface, each chamber defining an interior space wherein; one or more surface(s) of the second body includes a first port, a second port and two pressure equilibration openings in fluid communication with each other, one of the pressure equilibration openings being disposed one side of an axis which bisects the first and second ports, and the other of the pressure equilibration openings being disposed on the other side of the axis wherein each chamber together with the one or more surfaces of the second body forms a closed body unless the chamber is aligned with a port or opening in the one or more surfaces of the second body; a hopper at a first pressure, leading to the first port said hopper suitable for body the solid, wherein the first port allows access between the hopper and the interior of one of the chambers where the chamber is aligned with the first port, and alignment of one of the chambers and the first port allows transfer of the solid from the hopper to the chamber; a pressurised outlet channel at a second pressure leading from the second port to the pressurised fluid stream, wherein the second pressure is greater than the first pressure, and wherein the second port allows access between the pressurised outlet channel and the interior of one of the chambers where the chamber is aligned with the second port, and alignment of one of the chambers and the second port allows transfer of the solid from the chamber to the pressurised outlet channel and into the pressurised fluid stream wherein where one of the chambers is aligned with one of the pressure equilibration openings, and another of the chambers is aligned with the other of the pressure equilibration openings, the two chambers are in fluid communication with each other and the pressure between the two chambers is equilibrated.

Each of the ports and openings in the one or more surface(s) of the second body is alignable with an opening in the chambers. Generally, each of the ports and openings in the one or more surface(s) of the second body is alignable with an opening in each of the chambers.

Likewise, each opening in each chamber is generally alignable with at least one port or opening in the one or more surface(s) of the second body.

The one or more surface(s) of the second body generally includes the surface of the second body referred to above, provided proximal to the first surface of the first body. Accordingly, the surface of the second body provided proximal to the first surface of the first body generally includes at least one of the first port, the second port and the two pressure equilibration openings.

The first surface of the first body is generally biased against the surface of the second body. An opening in each of the chambers is thus typically biased against the surface of the second body where the chamber is not aligned with a port or opening in the surface of the second body.

Some or all of the chambers may extend to a second surface of the first body, the second surface being proximal to a second surface of the second body. In such embodiments, the second surface of the second body may include one or more of the first port, the second port and the two pressure equilibration openings, wherein the first and second surfaces of the second body together include all of the first port, the second port and the two pressure equilibration openings.

The first surface of the first body is suitably biased against the surface of the second body, and the second surface of the first body is generally biased against the second surface of the second body. Alternatively or additionally, there may be provided a sealing mechanism.

Generally, a single surface of the second body includes a first port, a second port and two pressure equilibration openings.

Each chamber generally includes one or two openings therein.

The chambers suitably extend from the first surface of the first body to a second surface of the first body, wherein the second surface is proximal to (and may be biased against) a second surface of the second body. In such embodiments, some of the specified ports and openings may be in the surface of the second body proximal to the first surface of the first body, and some may be in the second surface of the second body. In such embodiments, the first and second ports may be in the surface of the second body proximal to the first surface of the first body and the pressure equilibration openings (and optionally the exhaust port) may be in the second surface of the second body.

According to one embodiment, the first port and optionally the exhaust are provided in one surface of the second body (generally an upper surface of the second body) and the second port and the pressure equilibrium openings are provided in the second surface of the second body (generally a lower surface of the second body).

Where a chamber is not aligned with any of the first port, the second port, the two pressure equilibration openings and an exhaust port, a seal may be provided between each opening in the chamber and the one or more surfaces of the second body.

Where a chamber is aligned with any one of the first port, the second port, the two pressure equilibration openings and the exhaust port a sealing mechanism may be provided between each opening in the chamber and the edges of the first port, the edges of the second port, the edges of the two pressure equilibration openings or the edges of the exhaust port where the chamber is aligned therewith.

The sealing mechanism may be provided around the ports and openings, extending towards the first body, or the sealing mechanism may be provided around the opening(s) of the chambers, extending towards the second body. The sealing mechanism may be formed by any suitable means, for instance O-rings. This helps to ensure that the desired pressure in the chambers of the first body is maintained, as well as preventing, or greatly reducing, ingress or egress of fluid to the chambers.

Generally, each of the surfaces in the second body including any of the specified ports or openings is proximal to an opening in the chambers.

The apparatus of the present invention is energy efficient due to partial conservation of the pressure in the system. When aligned with the second port, and thus the pressurized outlet channel, one of the chambers of the first body becomes pressurized. When aligned with the first port, and thus the hopper, one of the chambers of the first body becomes depressurized. The apparatus of the present invention allows pressure between the two chambers to be equilibrated during movement between the first and second ports due to the provision of the pressure equilibration openings. This minimises the loss in pressure by 50%, resulting in a significantly more energy efficient system. The apparatus of the present teachings allows partial conservation of the pressure used to pressurise a first and second chamber of the first body through the incorporation of the pressure equilibration openings. The pressure between the first and second chambers is equilibrated prior to alignment of one of the first and second chambers with the second port. Accordingly, the additional pressure from the outlet port required is reduced, and the energy used to pressurise the outlet channel is partially conserved, along with the partial conservation of the pressurised air.

According to one embodiment, the solid is carbon dioxide, commonly known as “dry ice”. Dry ice changes between a solid and a gas with no intervening liquid phase (sublimates). This makes its behaviour difficult to predict and control. During sublimation, dry ice pellets can be seen to move around on a solid surface, or to hover slightly above a solid surface.

Each chamber, together with the one or more surfaces of the second body forms a closed body unless the chamber is aligned with a port or opening in the one or more surfaces of the second body (first and second port, exhaust port and pressure equilibration openings). Accordingly, air, heat and pressure cannot enter or leave the chambers where they are not aligned. As well as promoting the energy efficiency of the apparatus, the closed bodies of the chambers of the first body reduce the tendency of the solid to sublimate. This reduced tendency to sublimate makes the behaviour of the solid easier to predict and to control. Upon sublimation, dry ice initiates the formation of a frost residue from moisture in the atmosphere. This ices up machinery making it inefficient to run and restricting movement between parts.

During the dispensing systems and methods of the present teachings, the solid becomes pressurised prior to its introduction into the fluid stream. Typically, the solid remains pressurised from the pressurised outlet channel until introduction to the fluid stream. Maintaining such solids under pressure reduces their tendency to sublimate. The behaviour of the solids is thus more controllable and predictable under such conditions.

Generally, the first surface of the first body rotates relative to the surface of the second body and the surface of the second body is stationary Alternatively, the surface of the second body may rotate relative to the first surface of the first body.

The first and second bodies generally rotate in a horizontal plane rather than a vertical plane.

Typically, the chambers extending from the first surface extend within the first body and extend away from the surface of the second body.

The pressure equilibration openings are in fluid communication, generally through the inclusion of an equilibration body around the pressure equilibration openings but external to the chambers. The equilibration body may be in the form of a channel, a compartment or passage provided proximate to the surface of the second body in which the pressure equilibration openings are formed but externally to the chambers.

The apparatus described herein generally includes a channel or passage extending between the pressure equilibration openings to provide fluid communication there between.

Generally, where the chambers are aligned with the pressure equilibration openings, a closed system is formed between the interior of the chambers and the channel or passage extending between the pressure equilibration openings, and air, heat and pressure cannot enter or leave the closed system. This allows pressure to be equilibrated between two of the chambers within the first surface of the first body without significant loss in pressure from the system.

According to one embodiment, the pressure equilibration openings extend through a surface of the one of the one or more surface of the second body.

Generally, the one or more surface(s) of the second body includes an exhaust port allowing pressure to be dissipated from one of the chambers where the chamber is aligned with the exhaust port.

The exhaust port is suitably in the form of an opening through the surface of the second body and the exhaust port may be disposed between one of the pressure equilibrium openings and the first port.

The pressure in the aligned chamber is suitably reduced to atmospheric pressure. The chamber generally comes into alignment with the exhaust port during movement of the chamber from the second port to the first port, specifically during movement of the chamber from one of the pressure equilibration openings to the first port. Accordingly, the pressure in the chamber is generally the same as the pressure in the hopper when the chamber is moved into alignment with the first port.

The first and second bodies may be similarly shaped. The dimensions of the second body may be greater than the dimensions of the first body.

Generally, the first and second bodies are cylindrically shaped, typically conically shaped. According to one embodiment, at least one of the first and second bodies is shaped as a truncated cone, suitably both of the first and second bodies are shaped as a truncated cone.

The first surface of the first body and the surface of the second body proximal thereto may both be disposed at an angle of from around 20“ to around 40" from the longitudinal axis of the apparatus.

According to one embodiment, the first body is provided within the second body.

According to one embodiment, the first body may be provided between two surfaces of the second body. The first body may be in the form of a cylinder or truncated cone. The first surface of the cylinder or truncated cone may form one end of the cylinder or truncated cone, and the surface of the second body may be provided parallel thereto.

The hopper is pressurised to a lower pressure than the pressurised outlet channel, generally the hopper is at atmospheric pressure. When in alignment with the first port, the chambers are thus generally also unpressurised/at atmospheric pressure. However, when in alignment with the second port, the chambers become pressurised. The pressure from the alignment with the second port may be dissipated prior to alignment of the chamber with the first port through the inclusion of an exhaust port, or may be dissipated upon alignment with the first port.

The hopper is generally at a pressure of 1 atm (standard atmospheric pressure). The pressurised outlet channel is generally at a pressure of at least 10 atm, generally around 15 atm. Accordingly, where aligned with the two pressure equilibration openings, the pressure in the first and second bodies equilibrates and is generally from between 5 to 7.5 atm.

As noted above, the first surface of the first body is rotatably moveable relative to the surface of the second body. The first port may be considered to be at 0° rotation. Movement of a chamber between the first and second ports generally requires a rotation of the first surface relative to the surface of the second body of from between 100 to 260° rotation, suitably a rotation of from between 160 to 200° , generally a rotation of around 180° rotation. One of the pressure equilibration openings (the first opening) is provided between the first and second ports. Suitably, movement of a chamber from the first port to the first pressure equilibration openings requires a rotation of from 10 to 90% of the rotation necessary to move a chamber between the first and second ports. Typically movement of a chamber from the first port to the first pressure equilibration opening requires a rotation of from between 10 to 240°, suitably from between 70 to 110°, generally around 90. The other of the pressure equilibration openings (the second opening) is provided between the second and first ports. Generally movement of a chamber from the second port to the second pressure equilibration opening requires a rotation of from 10 to 90% of the rotation necessary to move the chamber from alignment with the second port to alignment with the first port. Typically moving the chamber from alignment with the first port to alignment with the second pressure equilibration opening requires rotation of from between 110 to 350°, generally from between 250 to 300°, suitably around 270°.

Generally, there is also provided an exhaust port between the second pressure equilibration opening and the first port. According to one embodiment, moving a chamber from alignment with the first port to alignment with the second pressure equilibration opening requires a rotation of 180 to 270°, and moving a chamber from alignment with the first port to alignment with the exhaust port requires a rotation of from 270 to 350°, typically around 300 to 320°.

According to one embodiment, where a chamber is not aligned with the specified ports and/or openings, the walls of the chamber, together with the surfaces of the second body provide a closed body, wherein ingress and egress of fluids and solids from the chamber is substantially or completely prevented, including ingress and egress of air and sublimated carbon dioxide. Transfer of heat and pressure into and out of the chamber is also substantially prevented where the chamber is not aligned with the specified ports and openings. A greater proportion of the solid is transferred from the hopper (at relatively low pressure) to the pressurised outlet channel than conventional systems as escape of the solid from the chambers is minimised or precluded accordingly. The solid to be dispensed into the pressurised air stream may be unstable, in particular, the solid may have a tendency to sublimate and transferring the solid within the largely closed system of the present invention minimises sublimation and increases the proportion of the solid dispensed into the pressurised fluid stream.

The first body may be provided within the second body, and the first body may be in the form of a container, such as a drum, provided between a top surface of the second body and a bottom surface of the second body. The chambers generally extend between the top and the bottom surfaces of the second body. The chambers are suitably provided at an incline toward the central axis of the drum, generally at an incline of 10 to 20° to the central axis of the apparatus, inclining inwardly from the top of the apparatus towards the bottom of the apparatus. The chambers body are generally provided at approximately the same incline to the longitudinal axis of the apparatus, suitably to the central axis of the rotatable drum. Typically, the chambers are substantially symmetrical about the central axis of the rotatable drum.

The preferred inclination of the chambers relative to the central axis of the drum reduces the sealed surface area on the bottom surface. In turn, this reduces the load applied by the lower pressure of the apparatus.

The ports and openings of the one or more surface(s) of the second body may be any suitable shape. Particular mention may be made of circular, oval and “tear drop” shaped apertures.

Generally, the solid is provided in pellets or tablets. The hopper generally vibrates to reduce the propensity of the solid to stick together. The hopper may comprise a storage section, narrowing towards the cooperating surface to provide unfettered access to the first port. The hopper may include a spike extending from the storage section towards the first port. The inclusion of a spike reduces the amount of the solid which sticks together.

Generally, the pressurised fluid stream is a pressurised gas stream, typically a pressurised air stream.

The pressurised outlet channel generally extends from an outer wall of the second body extending from the second port. The pressurised outlet channel generally leads to a, or the dispenser for the solid, which dispenses the solid into the pressurised fluid stream, generally in a metered amount. The pressurised outlet channel may lead directly to the pressurised metering device, or may lead to a storage compartment which subsequently leads to the metering device. Advantageously, the solid is dispensed into the fluid stream at a constant rate, allowing a constant delivery of the mixture. Typically, upon dispensation into the fluid, the solid sublimates.

According to one embodiment, the pressure on the solid is substantially maintained from the outlet channel to dispensation into the fluid stream. Generally, the pressurised outlet channel is at the same pressure as the pressurised fluid stream, although this may vary by up to 20%, generally by up to 10%. Suitably, the pressure may be increased between the outlet channel and the fluid stream, generally by 10% or less.

Suitably the solid remains under pressurised conditions between transfer from the chambers of the first body of the apparatus described herein into the pressurised outlet channel until dispensation into the pressurised fluid stream.

The dispenser generally rotates between the position where the housing is aligned with the third port, and the position in which the housing is aligned with the fluid stream.

The dispenser is generally cylindrical, and the housings extend between one end of the cylinder and the other.

According to one embodiment, the movement of the dispenser between the position in which a housing is aligned with the third port, and a position in which the housing is aligned with the fluid stream is non-horizontal, generally such movement is substantially or completely vertical. Such movement is promoted by the action of gravity, and this can overcome some of the unpredictability of the movement/behaviour of sublimating solids such as dry ice.

Suitably the dispenser is disposed non-horizontally, generally the dispenser is disposed substantially vertically.

Generally, the fluid stream moves in a substantially straight line through the dispenser. Suitably the fluid stream is substantially straight for a distance of at least 10 cm before it reaches the dispenser, typically for at least 10 cm after it reaches the dispenser. This maximises the efficiency of the system as changes of direction of the pressurised fluid stream lead to a loss in energy.

Generally, each housing houses a predetermined, metered amount of the solid. Suitably, the capacity (by volume) of each housing within a dispenser is the same to within 10 vol.%.

The dispenser generally includes five or more housings, typically ten or more housings, suitably fifteen or more housings.

The capacity of each housing is dependent on the concentration of solid required in the pressurised fluid stream and this is generally dependent on the intended use.

According to one embodiment, the dispenser comprises housings at different distances from the outside edge of the dispenser, generally at two or three different distances. Generally, the housings at different distances are of different shape, but the same volume (or having a volume within 10 %). Preferably, the overlap between the volume of one or more housing(s) and the fluid stream is approximately the same as the dispenser moves, generally within 10 % area, suitably within 5 % area. This ensures or promotes a fairly constant dispensation of solid into the fluid stream.

According to one embodiment, each housing includes a radial opening through the outside edge of the dispenser. In such embodiments, the third port may provide access between the body and the outside edge of the dispenser.

The solid may be transferred from the outlet channel, or the storage compartment into a housing of the dispenser. The dispenser is generally in the form of a rotatable disk with housings for the solid provided, generally towards the circumference of the disk. As the disk rotates, a metered amount of the solid may be released from the pressurised outlet channel, or a storage compartment leading from the outlet channel to each of the housings of the dispenser.

Each housing is generally movable between the third port and the pressurised fluid stream upon rotation of the dispenser. Suitably the pressurised fluid stream flows through the dispenser, generally flowing through one or more of the housings which are aligned with the pressurised fluid flow, and thus displacing the solid housed in the one or more housings into the pressurised fluid stream.

According to one embodiment, the dispenser is detachable. This is useful for cleaning the device, storing the device. The device may be in the form of a kit including a selection of different dispensers, wherein each dispenser has housings of different capacities. The dispenser having housings of the appropriate capacity may be selected dependent on the intended use.

Method

According to one embodiment, the first body is in the form of a rotatable drum, and the chambers are formed within one end thereof, typically extending to the second end thereof. The rotatable drum, is suitably sandwiched between two surfaces of the second body, the two surfaces generally remaining stationary during the method of distribution. Suitably, rotation of the rotatable drum allows movement of the chambers between alignment with the first port, to alignment with one of the pressure equilibration openings, to alignment with the second port, to alignment with the other of the pressure equilibration openings, and subsequently to alignment with the first port.

According to one embodiment, the chambers are brought into alignment with the exhaust port between alignment with the other of the pressure equilibration openings and alignment with the first port.

According to a further aspect of the present invention there is provided a method of distributing a solid into a pressurised fluid stream comprising: providing the device as described herein, transferring solid from the pressurised outlet channel, through the port into a housing of the dispenser, moving the dispenser into a position in which the housing is aligned with the fluid stream, wherein the flow of the pressurised fluid stream displaces the solid from the housing into the fluid stream.

According to one embodiment, the housings are spaced within the dispenser such that the same volume of one or more housings is aligned with the fluid stream as the dispenser moves.

According to one embodiment, the two abovementioned methods may be combined.

Kit

According to an aspect of the present invention, there is provided a kit of parts comprising an apparatus as described herein and instructions for use.

According to an aspect of the present invention, there is provided a kit of parts comprising a device as described herein and instructions for use.

Optionally the kit includes more than one dispenser, each dispenser including housings of different sizes. A dispenser can be selected depending on the required use of the device.

According to one embodiment, there is provided a kit including an apparatus and a device as described herein, and instructions for use.

Kits can further include instructions for performing the methods described herein and/or interpreting the results, in accordance with any regulatory requirements. In addition, software can be included in the kit for example for analysing the rate of release of the solid and/or for analysing the concentration of solid in the fluid stream. Preferably, the kits are packaged in a container suitable for commercial distribution, sale, and/or use, containing the appropriate labels, for example, labels including the identification of the different components of the apparatus/device.

The present invention will now be described by way of example only with reference to the accompanying figures in which:

Figure 1 shows a representation of a rotating drum for use in an embodiment of the apparatus of the present invention;

Figure 2 shows a representation of the internal drum of the apparatus of Figure 1, upside down;

Figure 3 shows a representation of the upper plate of the apparatus of Figure 1;

Figure 4 shows a representation of the lower plate of the apparatus of Figure 1;

Figure 5 shows a representation of the rear of the cylindrical body of the dispenser of the distributer assembly of the present invention;

Figure 6 shows the front view of the cylindrical body of the dispenser of Figure 5; Figure 7 shows a body plate of the distributer assembly;

Figure 8 shows a distributer of the present invention;

Figure 9 shows an embodiment of the distributer assembly of the present invention Figure 10 shows an embodiment of the apparatus of the present invention;

Figure 11 shows a view of the top of the second body of the apparatus of Figure 10; Figure 12 shows a view of the underside of the second body of the apparatus of Figure 10.

The assembly of the present invention allows for the pressurisation of individual chambers of dry ice pellets for delivery to a feeding system. Figure 1 shows a rotatable drum, 1, including an internal drum, 2 (first body) sandwiched between an upper plate, 3 and a lower plate, 4 (the upper plate and the lower plate constituting the second body). The internal drum, 2, is rotatable relative to the upper plate 3 and the lower plate 4. The upper plate and the lower plate remain stationary. Two chambers (not shown in Figure 1) are formed within the internal drum, 2.

The internal drum, 2 houses a first and second chamber 10, 11 extending the height of the internal drum. One end of each of the first and second chambers 10, 11 is biased against the upper plate 3, and the other end of the first and second chambers 10, 11 is biased against the lower plate 4. The central axis of the first and second chambers 10, 11 is inclined towards the central axis of the internal drum, 2, as it extends from the upper plate, 3, to the lower plate, 4. Generally the angle between the central axis of the first chamber 10 and the central axis of the internal drum is from 10 to 20 degrees. Through boring the first and second chambers at an inclination to the central axis of the internal drum, the sealed surface area on the bottom face of the internal drum may be reduced. In turn, this reduces the load applied by the lower pressure of the rotatable drum assembly. This “line pressure” is held by the movement of the pressurised fluid stream as it passes through the rotatable drum assembly and is maintained over the sealed area of the lower face. In addition to this total bottom seal, each of the first and second chambers is sealed at the top and bottom by O-rings. This ensures that the first and second chambers maintain their desired pressure, regardless of their position around the cycle of rotation of the internal drum. The internal drum also has a square drive slot at its centre.

The second body includes an upper plate and a lower plate. The upper plate (Figure 3) is in the form of a stainless steel disk with a teardrop-shaped ice pellet inlet hole (a) (the first port) and a small exhaust port (b). It also has a circular pattern of holes around its outer edge which accommodates the holes for the pillar bolts. The first port (a) leads from the hopper output, which supplies a steady stream of pellets from a vibrating hopper. The first body, in the form of the internal cylinder 2 is driven by a motor that is positioned above the whole setup. In order to allow this motor’s axle through to the internal cylinder 2, the upper plate also has a central hole (c).

The lower plate 4 (Figure 4) is similar to the top plate, with a circular pattern of bolt holes and a teardrop-shaped opening 20 which forms the second port. The lower plate also includes two smaller holes 22 through it that are connected externally (external connection not shown). These are pressure equilibration openings.

In the starting position, the first chamber 10 is at atmospheric pressure and positioned below the ice inlet (first port) a on the top plate. The first chamber 10 will thus fill with pellets. The second chamber 11 is positioned over the second port 20 on the bottom plate, dropping its load into the pressurised outlet channel. The second chamber 11 is at the pressure of the pressurised fluid flow (line pressure). As the internal drum 2 rotates, this now empty second chamber 11 moves over the larger of the two pressure equilibration openings 22. Just as the second chamber 11 is moving off the larger pressure equilibration opening 22, the first chamber 10 is moving over the smaller pressure equilibration opening 22. This results in a pressure equalisation between the first and second chambers 10, 11.

Further rotation results in the second chamber 11 moving off its pressure equilibration opening 22 entirely, leaving the full first chamber 10 still on the smaller pressure equilibration opening 22. This first chamber 10 is therefore brought to line pressure by the constant pressure maintained on the bottom sealed surface of the cylinder 2. Next, the second chamber 11 passes over the exhaust port b allowing the pressure in the second chamber 11 to return to atmospheric pressure. Finally, the internal drum 2 completes its 180° cycle by emptying the ice from the first chamber 10 into the pressurised outlet channel and filling the second chamber 11 with a fresh batch of ice pellets. A further embodiment of the apparatus of the present invention is illustrated in Figures 10 to 12. Figure 10 shows an apparatus 100, wherein the first body 110 is in the form of a truncated cone including chambers therein 120. The second body 130 is also in the form of a truncated cone including the first port 140, the second port 150 and the pressure equilibration openings 151 and 152.

In use, dry ice pellets are provided in the hopper (not shown), and move through a loading funnel (125) to the first port 140 to a first chamber 121. The first body rotates relative to the second body, moving the chambers from alignment with the first port 140 to the second port 150. The 150 second port is aligned with the pressurised outlet channel 160. During movement between the first port 140 and the second port 150, the chambers 120 are aligned with one of the pressure equilibration openings 151. A second chamber 122 within the truncated cone which forms the first body 110 is simultaneously aligned with the other of the pressure equilibration openings 151. The pressure between the first and second chambers 121, 122 is equilibrated accordingly. Likewise, between movement of the first chamber 121 from the second port 150 towards the first port 140, the first chamber 121 becomes aligned with the other of the pressure equilibration openings 152, and the second chamber becomes aligned with the pressure equilibration opening 151. The pressure between the first and second chambers 121 122 is equilibrated accordingly.

Ice pellets are fired down the second port 150 (the large circular port in Figure 11) at operating pressure. This can be up to 16 bar. Once the chambers 120 have been vacated, with the solid emptying from them the vacated but still pressurised chambers 120 pass over the pressure equilibration openings 152 (small holes).

On the reverse side of the second body (as shown in Figure 12), tubes (not shown) run between the pressure equilibration openings ports 151 and 152, and so the pressure between the chambers 120 on each side is equalised. This makes the process more efficient as each chamber 120 does not have to be taken up to operating pressure from atmospheric whenever the solid material is discharged.

The chambers 120 are at approximately half of the operating pressure by the time they come into contact with the second port 150. In order to facilitate this pressure equalisation, a seal is maintained between the first body 110, the second body 130 and the casing of the apparatus. In this case, the seal is maintained mechanically, by the actuator. It pushes a lever that applied a load to an insert on the case. This insert mirrors the one on the second body 130 which has the equalisation ports in it, except for the fact that it lacks the ports themselves. The inserts are also slightly proud of their surroundings, resulting in a pinch point that seals all of the chambers 120 that pass through it.

Device for the Distribution of a Solid into a Pressurised Fluid Stream (Figures 5 to 9)

This system distributes dry ice pellets into a pressurised feed line at a constant rate. This results in a constant mix of air and ice being delivered along the line to its required output. It consists of a feed cylinder, an aluminium body, a stepper motor, an input pipe and an output pipe.

Figure 5 shows a front perspective view of the body 50 used to house the feed cylinder 60 of the device. The body is built of two parts. The first is an aluminium cylinder 50, as shown in Figure 5, with a large central reservation 52 bored out for the feed cylinder, along with a threaded hole 55 for the output pipe. A circular pattern of threaded holes around the back face of the body, is present in order to allow the back plate to be bolted on. 51 is an axle hole that allows the feed cylinder’s drive connection to be fitted to the stepper motor’s drive shaft. Grooves 53 and 54 accommodate static O-ring seals that keep the unit under constant pressure.

Figure 6 shows a back view of the body 50. Here we can see a circular cut away around the axle hole 51 which accommodates a dynamic seal. It is held in place by a plate which is attached to the body by bolts secured into the inner circular pattern of five threaded holes. The outer pattern of four holes is to allow the attachment of the motor that drives the feed cylinder 60. The top of the body has a cylindrical pipe section with the rest squared off. This area also has an array of threaded holes for the body’s attachment to the connection system to the rest of the machine.

The second section of the body 50 is the plate 56 (Figure 7). This plate 56 has an indent 57 milled into the inside of it to allow for the support section of the feed cylinder 60. It also has a threaded inlet 58 for the inlet pipe of the feed line. This lines up with the previously described threaded output 55 on the cylinder 50. The circular pattern of holes around the outside of the plate lines up with the pattern on the body wall and allows the two sections to be bolted together.

The feed cylinder distributer itself 60 (as shown in Figure 8) is plastic, with a front drive cavity, rear mounting support and a venting system. This system is comprised of axial and radial slots. The axial slots 61 are arranged in a circular pattern on the front face and pass through the entirety of the piece. There is one radial slot per axial slot 62, positioned in the centre of each axial slot 61. These feed slots 62 can be made larger or smaller, depending on the performance required from the model. They are also chamfered at the top in order to easily collect the ice pellets. The rear support 63 is a simple cylindrical extrusion. The cavity at the front accepts a shaft which is in turn connected to the stepper motor’s output.

The completed assembly can be seen in Figure 9. Here, the motor, outlet pipe 72 and top inlet fixture 71 have been added. The body plate has been made transparent, so that the feed cylinder can be observed. To begin with, ice falls down the top fixture 71 and fills the chamber beneath it. This is a constant process. Once a filled chamber reaches the outlet pipe, pressurised air from the inlet pipe feeds the ice into the line. Due to the design of the cell, the area available to be dispensed is continuous no matter which section of the cylinder is in action.

Various modifications and variations of the described aspects of the invention will be apparent to those skilled in the art without departing from the scope and spirit of the invention. Although the invention has been described in connection with specific preferred embodiments, it should be understood that the invention as claimed should not be unduly limited to such specific embodiments. Indeed, various modifications of the described modes of carrying out the invention which are obvious to those skilled in the relevant fields are intended to be within the scope of the following claims.

Claims

1. An apparatus for the distribution of a solid into a pressurised fluid stream comprising: a first body and a second body, wherein the first body includes a first surface, provided proximal to a surface of the second body and the first surface is rotatable relative to the surface of the second body; wherein the first body comprises at least two chambers extending from the first surface, each chamber defining an interior space wherein; one or more surface(s) of the second body includes a first port, a second port and two pressure equilibration openings in fluid communication with each other, one of the pressure equilibration openings being disposed one side of an axis which bisects the first and second ports, and the other of the pressure equilibration openings being disposed on the other side of the axis wherein each chamber together with the one or more surfaces of the second body forms a closed body unless the chamber is aligned with a port or opening in the one or more surfaces of the second body; a hopper at a first pressure, leading to the first port said hopper suitable for housing the solid, wherein the first port allows access between the hopper and the interior of one of the chambers where the chamber is aligned with the first port, and alignment of one of the chambers and the first port allows transfer of the solid from the hopper to the chamber; a pressurised outlet channel at a second pressure leading from the second port to the pressurised fluid stream, wherein the second pressure is greater than the first pressure, and wherein the second port allows access between the pressurised outlet channel and the interior of one of the chambers where the chamber is aligned with the second port, and alignment of one of the chambers and the second port allows transfer of the solid from the chamber to the pressurised outlet channel and into the pressurised fluid stream wherein, where one of the chambers is aligned with one of the pressure equilibration openings, and another of the chambers is aligned with the other of the pressure equilibration openings, the two chambers are in fluid communication with each other and the pressure between the two chambers is equilibrated.

2. The apparatus of claim 1 wherein the first surface of the first body is biased against the one or more surfaces of the second body.

3. The apparatus as claimed in any preceding claim wherein one surface of the second body includes a first port, a second port and two pressure equilibration openings.

4. The apparatus as claimed in any preceding claim wherein the chambers extend from the first surface of the first body to a second surface of the first body, wherein the second surface is proximal to a second surface of the second body.

5. The apparatus as claimed in claim 4 wherein the first and second ports are in the first surface of the second body and the pressure equilibration openings are in the second surface of the second body.

6. The apparatus as claimed in any preceding claim wherein where a chamber is not aligned with any of the first port, the second port, the two pressure equilibration openings and an exhaust port, a seal is provided between each opening in the chamber and the one or more surfaces of the second body.

7. The apparatus as claimed in any preceding claim wherein where a chamber is aligned with any one of the first port, the second port, the two pressure equilibration openings and an exhaust port a seal is provided between each opening in the chamber and the edges of the first port, the edges of the second port, the edges of the two pressure equilibration openings or the edges of the exhaust port.

8. The apparatus as claimed in any preceding claim comprising a channel or passage extending between the pressure equilibration openings to provide fluid communication there between.

9. The apparatus as claimed in either one of claim 1 and claim 2 wherein the first body is provided within the second body.

10. The apparatus as claimed in any one of claims 1 to 3 wherein first and second body are similarly shaped.

11. The apparatus as claimed in any preceding claim, wherein, the dimensions of the second body are greater than the dimensions of the first body.

12. The apparatus as claimed in any preceding claim wherein the first surface of the first body and the surface of the second body are both disposed at an angle of from around 20° to around 40° from the longitudinal axis of the apparatus.

13. The apparatus as claimed in any preceding claim wherein one or both of the first and second body is shaped as a truncated cone.

14. The apparatus as claimed in any preceding claim wherein the pressure equilibration openings extend through one of the one or more surfaces of the second body.

15. The apparatus as claimed in any preceding claim wherein the chambers extending from the first surface extend within the first body and extend away from the surface of the second body.

16. The apparatus as claimed in any preceding claim wherein the surface of the second body includes an exhaust port allowing pressure to be dissipated from a chamber in the first surface of the first body where the chamber is aligned with the exhaust port.

17. The apparatus as claimed in claim 10 wherein the exhaust port is in the form of an opening through the surface of the second body and the exhaust port is disposed between one of the pressure equilibrium openings and the first port.

18. The apparatus as claimed in any preceding claim wherein the chambers together with the surface of the second body provide closed chambers where the chambers are not in alignment with the first, second or exhaust ports or are not in alignment with the pressure equilibration openings, wherein ingress and egress of fluids and solids from the closed chambers is substantially or completely prevented.

19. The apparatus as claimed in any preceding claim wherein the chambers each house a metered amount of the solid.

20. The apparatus as claimed in any preceding claims wherein the volume of each chambers is the same to within 10% by volume.

21. The apparatus as claimed in any preceding claim comprising chambers at two or more different distances from an outside edge of the first surface of the first body wherein each chamber has the same volume.

22. The apparatus as claimed in any preceding claim wherein the solid consists or consists essentially of carbon dioxide and the pressurised fluid stream consists or consists essentially of air.

23. The apparatus as claimed in any preceding claim including a dispenser suitable for dispensing the solid from the pressurised outlet channel into the pressurised fluid stream, wherein the pressurised fluid stream flows through the dispenser, from one side of the dispenser to another side of the dispenser; wherein the dispenser comprises more than one housing for the solid, each housing extending from one side of the dispenser to the other side of the dispenser, a third port, providing access between the pressurised outlet channel and a housing of the dispenser where the housing is aligned with the third port, allowing transfer of the solid from the pressurised outlet channel to the housing, wherein the dispenser is movable between a position where a housing is aligned with the third port, and a position in which the housing is aligned with the fluid stream, and the fluid stream flows through the housing; wherein the device is at a pressure of from 80 to 120% of the pressure of the pressurised fluid stream.

24. A method of distributing a solid into a pressurised fluid stream comprising: providing the apparatus as claimed in any one of claims 1 to 23, aligning a first chamber with the first port, and transferring solid from the hopper to the first chamber, aligning a second chamber with the second port, and thus allowing access between the pressurised outlet channel and the interior of the second chamber causing the pressure within the second chamber to increase, rotating the first surface of the first body relative to the surface of the second body to bring the first chamber into alignment with one of the pressure equilibration openings, and to bring the second chamber into alignment with the other of the pressure equilibration openings and thus equilibrating the pressure between the first and second chambers, rotating the first surface of the first body relative to the surface of the second body to bring the first chamber into alignment with the second port and thus allowing access between the pressurised outlet channel and the interior of the first chamber causing the pressure within the first chamber to increase, and solid from the first chamber to be transferred to the pressurised outlet channel, rotating the first surface of the first body relative to the surface of the second body to bring the second chamber into alignment with the first port, and transferring solid from the hopper to the second body, rotating the first surface of the first body relative to the surface of the second body to bring the first chamber into alignment with one of the pressure equilibration openings, and to bring the second chamber into alignment with the other of the pressure equilibration openings and thus equilibrating the pressure between the first and second chambers, rotating the first surface of the first body relative to the surface of the second body to bring the first chamber into alignment with the first port, wherein the solid is dispensed from the pressurised outlet channel, to a dispenser and into the pressurised fluid stream.

25. A method as claimed in claim 24 wherein the concentration of the solid material in the fluid stream is substantially constant, suitably wherein fluctuations in the concentration are less than 10%.

26. A kit comprising the apparatus as claimed in any one of claims 1 to 23, and instructions for use.

27. A kit as claimed in claim 26 comprising more than one removable dispenser wherein each dispenser includes chambers having a different capacity.