Gas-particle processor

Abstract

A gas-particle processor for contacting a flow of particles with a gas flow, comprising: a chamber; at least one gas inlet for introducing a gas into the chamber, the gas forming an accelerated gas flow and a primary gas flow in the chamber; a particle feeder in fluid communication with the particle inlet for introducing a flow of particles into the gas; and a separator for separating the accelerated gas stream from the main gas stream in at least part of the chamber wherein the accelerated gas stream has a higher average velocity than the main gas stream to form a curtain of the particle stream having an upstream edge and a downstream edge; and a particle outlet for receiving a curtain of the particle stream.

Description

Technical Field

[0001] The present invention relates to a method and an apparatus for treating particles using a gas.

[0002] The present invention relates particularly, but by no means exclusively, to methods and apparatus for achieving one or more of heat transfer, mass transfer and chemical reactions between particles and a gas.

[0003] The present invention relates particularly, but by no means exclusively, to a method and apparatus for drying particles using a gas stream.

[0004] The present invention also relates by no means exclusively to a method and apparatus for coating and drying particles using a gas stream. Background Art

[0005] Gas-particle processors such as fluidized beds have a wide range of applications including fluid catalytic cracking, flue gas cleaning and ore roasting.

[0006] However, one problem faced by gas-particle processing is the inadequate distribution of the contact of the particle flow with the gas flow, which in turn can lead to a reduction in the overall heat and / or mass transfer and / or interphase reaction between the two flows. Other problems faced by gas-particle processing include the difficulty in accurately controlling one or both of the gas flow and the particle flow and high pressure drop.

[0007] Another disadvantage of fluidized bed and rotary drum gas-particle processors is that they may damage the particles due to prolonged exposure to mechanical and thermal stresses.

[0008] It would therefore be desirable to provide a gas-particle processor having improved fluid and particle dynamics. Summary of the invention

[0009] Applicants have developed a method and apparatus for feeding particles into a gas-particle processor such that the gas flow and particle flow interact to form one or more particle curtains in the chamber of the processor. The method and apparatus are described in International Publication No. WO2012 / 068631, which is incorporated herein by cross-reference.

[0010] Particles enter the chamber from the feed port and come into contact with a generally horizontal gas flow, forming a particle curtain. The particle trajectory consists of horizontal and vertical components, and the flow regime of the particles changes as the particles fall through the top of the curtain. Due to the change in particle flow regime, it is difficult to achieve a uniform distribution of particles in the curtain to achieve effective gas-particle contact. During the course of the experiment, the applicant observed that particles at the upstream or leading edge of the curtain fell more vertically than horizontally. Without being bound by theory, it is believed that this observation is due to the failure of the gas flow to penetrate the particle curtain.

[0011] It is believed that the particle curtain interferes with the horizontal passage of gas flow. Instead of the gas at the top of the curtain following a horizontal flow line through the curtain, the top of the falling particle stream acts as a barrier to the horizontal flow. This causes the gas in the curtain to flow downward as the gas turns to the more porous portion of the curtain in order to flow through and escape downstream.

[0012] It is recognized that the shape and size of the curtain are two factors that affect the heat transfer effect.

[0013] Applicant's research has led to the recognition that a particle curtain is affected by forces such as pressure gradients and induced flow dynamics, and that heat and / or mass transfer and / or chemical reactions between the particle stream and the gas stream can be optimized by manipulating the shape and size of the curtain. This improves the properties and interactions between the gas and particle streams, such as straightness of the gas stream, higher effective surface area per unit volume of particles in the curtain, and particle residence time.

[0014] Applicants are seeking to reduce the pneumatic transport behavior, where particles begin to flow horizontally through the chamber in the direction of the primary gas flow, and increase the cross-flow contact of gas to particles.

[0015] Further research by the applicant has also led to the recognition that the accelerating gas flow may play an important role in maintaining the shape and size of the curtain to achieve improved heat and / or mass transfer and / or chemical reaction, particularly because the accelerating gas can be used to direct the particles so that they are introduced into the chamber at an angle to the vertical. The accelerating gas may also serve to make the gas flows of the accelerating gas and the main gas as vertical as possible, thereby increasing the average glide velocity within the curtain.

[0016] The present invention provides a gas-particle processor for contacting a particle flow with a gas flow, comprising:

[0017] Chamber;

[0018] at least one gas inlet for introducing a gas flow into the chamber, the gas forming an accelerating gas flow and a main gas flow in the chamber;

[0019] a particle feeder in fluid communication with the particle inlet for introducing a flow of particles into the gas;

[0020] a separator for separating an accelerated gas stream from a main gas stream in at least a portion of the chamber, wherein the accelerated gas stream has a higher average velocity than the main gas stream to form a curtain of particle flow having an upstream edge and a downstream edge; and

[0021] A particle outlet is used to receive a curtain of particle flow.

[0022] In this specification, the term "particles" includes solid particles and liquid particles, for example in the form of droplets or flakes.

[0023] In this specification, the term "curtain" is understood to mean the area occupied by particles in a gas-particle contactor with the vertical component of their particle velocity when they contact a horizontal gas flow. The particle curtain includes finer / smaller sized particles that tend to accumulate toward the downstream (rear) edge of the curtain and coarser / larger sized particles that tend to accumulate toward the upstream (front) edge of the curtain. A large portion (greater than 50%) of the particles in the curtain can be collected at the particle outlet at the bottom of the processor.

[0024] In this specification, the term "separator" is understood herein to include any term such as a partition, a tongue, a flange, a baffle, a distributor, etc., which is used as a tool to divide the total air flow into two air flows.

[0025] The separator is located in the chamber and is used to maintain different velocities of the accelerated airflow and the main airflow. The separator can separate the airflow into the accelerated airflow and the main airflow with different velocities.

[0026] The separator may be located before and / or after the particle inlet.

[0027] The separator may be located upstream or downstream of the particle outlet. The separator separates the gas into gas streams to form another curtain of particles having an upstream edge and a downstream edge before contacting the reintroduced curtain of particle flow or the curtain of fresh feed particles.

[0028] The separator may be positioned to provide an accelerating gas zone having a height of at least 0.05 m, typically in the range 0.05 to 1 m.

[0029] The separator may be positioned to provide a clearance angle greater than 20°, typically 30 to 90°, more typically 70 to 90°, and even more typically 85 to 90°.

[0030] The clearance angle is defined by the following formula:

[0031]

[0032] The separator protrusion is the length of the separator protruding to the particle inlet.

[0033] The separator may have a solid structure. In this embodiment, the separator does not include perforations that allow fluid to flow through the separator.

[0034] The separator may have perforations. In this embodiment, the perforations allow fluid to flow through the separator. Typically, the perforations are sized to allow particles to pass through them. The perforations may have a diameter of at least 0.1 mm, typically at least 1 mm, and more typically at least 10 mm.

[0035] The area of ​​the perforations may be at least 5% of the area of ​​the separator. The area of ​​the perforations may be between 20% and 80% of the area of ​​the separator.

[0036] Applicants have discovered that directing the particle stream first into a first gas stream having a higher velocity and then directing the particles into a second gas stream having a lower velocity improves the distribution of the particles in the curtain. It has been observed that this method of introducing the particles into the gas stream increases the distribution of the top of the falling particle stream, which would otherwise act as a barrier to the horizontal gas stream and cause the gas in the curtain to flow downward as the gas is diverted to the more porous portions of the curtain to flow through and escape downstream.

[0037] A gas inlet can be used to introduce gas into the chamber and be divided into an accelerated airflow and a primary airflow. Alternatively, the separated accelerated airflow and primary airflow can be introduced into the chamber. Suitably, the accelerated airflow is introduced into the chamber area above the separator, and the primary airflow is introduced into the chamber area below the separator.

[0038] The accelerated air flow may flow through an upper region of the chamber.

[0039] The accelerating airflow and the main airflow may be introduced into the chamber separately.

[0040] The gas-particle processor may include a plurality of gas inlets and a plurality of particle inlets.

[0041] The gas-particle processor may include at least two pairs of particle inlets and outlets, wherein a first particle outlet is in fluid communication with a second particle inlet.

[0042] In one embodiment, at least two particle curtains are formed, wherein a first curtain is formed between a first pair of particle inlets and outlets, and a second curtain is formed between a second pair of particle inlets and outlets. In other words, the second particle inlet reintroduces the first curtain into the chamber as a second curtain.

[0043] In another embodiment, the first and second particle inlets may not be arranged in chronological order. For example, the first and second particle inlets may be positioned in a reverse cascade order, with the first particle inlet being located after the second particle inlet. This may allow optimization of the temperature / concentration driving force.

[0044] The gas inlet and the particle inlet may be configured to introduce the gas flow and the particle flow in a cross-flow arrangement.

[0045] In this specification, the term "cross flow" is understood herein to include contact between an air flow and a particle flow, wherein the particle flow and the air flow flow in different directions. This includes contact between the particle flow and the air flow in perpendicular directions and non-perpendicular directions, as long as the particle flow and the air flow do not flow in the same direction.

[0046] The at least one gas inlet may be positioned to introduce gas into the chamber in a substantially horizontal direction.

[0047] The particle inlet may be configured to deliver the particle stream into the air stream in a substantially vertical direction. Typically, the particle inlet is positioned to deliver the particle stream into the air stream in a substantially downward direction. More typically, the particle inlet is positioned to deliver the particle stream into an accelerating air stream.

[0048] The particle stream may be introduced into the accelerating gas stream at an angle between the particle stream and a horizontal component of the accelerating gas stream that is greater than 20 degrees, typically ranging from 60 degrees to 90 degrees, and more typically ranging from 85 degrees to 90 degrees.

[0049] The gas-particle processor may be configured to enable bidirectional flow of one or both of the particle flow and the gas flow. Suitably, the gas-particle processor is configured to enable bidirectional flow of the gas flow.

[0050] The gas-particle processor can be configured to achieve a bidirectional cross-flow of particle and gas streams. This allows the particle curtain to be exposed to gas streams from multiple consecutive directions.

[0051] In one example, a first horizontal airflow is directed in a first direction, cross-flow with the particle curtain, and then directed in a second direction opposite the first direction to change the direction of the particle curtain.

[0052] In this example, the bidirectional cross-flow system includes a cross-flow region in which a first horizontal gas flow contacts the particle curtain along a first direction.

[0053] The position of the separator within the cross-flow region may be adjustable. Suitably, the height and length of the separator are adjustable.

[0054] The position of the separator between the cross-flow regions may be adjustable. Suitably, the height and length of the separator are adjustable.

[0055] In this example, each airflow is separated into an accelerating airflow and a main airflow. Suitably, the airflow is directed to a separator to separate the airflow into the accelerating airflow and the main airflow. The separator can maintain different speeds of the accelerating airflow and the main airflow along the length of the chamber.

[0056] The amount of airflow determines the amount of curtains formed within the chamber.

[0057] The accelerating airflow may be located above the primary airflow.

[0058] The accelerated airflow may be formed above the separator. The term "above" is understood herein to include the accelerated airflow flowing in the chamber at a height greater than the height of the separator.

[0059] The main airflow may be formed below the separator. The term "below" is here to be understood to include the main airflow flowing in the chamber at a height less than the height of the separator.

[0060] In one embodiment, the gas-particle processor comprises a horizontally arranged chamber. In this embodiment, the gas flow flows along the length of the chamber, the width of the particle curtain is defined by the width of the chamber, and the distance the particles fall is defined by the height of the chamber.

[0061] In a multi-stage operation involving the formation of multiple particle curtains in the gas-particle contactor, a separator may be located before each particle inlet. This allows the gas near each particle inlet to be separated into an accelerating gas stream and a main gas stream. It also allows the particles introduced into the contactor through each particle inlet to first contact the accelerating gas stream.

[0062] The gas-particle processor can be configured to increase the average slip velocity. The slip velocity is the magnitude of the relative velocity component of the gas relative to the particles flowing in contact with each other. The slip velocity can be defined by the following equation, where the x, y, and z terms refer to the horizontal dimension (e.g., length), vertical dimension (e.g., height), and width dimension of the chamber:

[0063]

[0064] The gas-particle processor may be configured to achieve an average glide velocity that is at least 10% higher, typically at most 15% higher, and more typically at most 26% higher, compared to a gas-particle processor without a separator.

[0065] The gas-particle processor can be configured to achieve straightness of the gas flow after the first curtain. The straightness of the gas flow is measured by the effective height factor defined by the following formula:

[0066] Effective height factor = height of 90% of the primary airflow in the treatment area / height of the treatment area.

[0067] Airflow straightness is measured for the streamlined airflow of the primary airflow flowing along the length of the processor.

[0068] The effective height factor is the height factor at which 90% of the primary airflow exists in the treatment area.

[0069] Suitably, the effective height factor has a value greater than 0.50. More suitably, the effective height factor ranges from 0.50 to 0.90.

[0070] The gas-particle processor may be configured such that less than 10 weight percent, typically less than 7 weight percent, more typically less than 5 weight percent of the particle stream contacts the separator.

[0071] One of the applicant's concerns is to develop a gas-particle processor that optimizes heat and / or mass transfer between the gas flow and the particle flow in the processor, and it can be determined that the residence time of the particle flow in the gas-particle processor is an important factor affecting the heat and / or mass transfer.

[0072] In any given case, the heat and / or mass transfer effects of a gas-particle processor and the average residence time of particles in the gas-particle processor may be controlled by many factors, including one or more of the following:

[0073] - slip speed,

[0074] - particle volume velocity,

[0075] -Speed ​​ratio,

[0076] - percentage separator prominence, and

[0077] - Type of particles.

[0078] For example, minimizing the volume velocity of a falling curtain of particles may increase the residence time and / or total available surface area of ​​the particles within the chamber and thereby enhance heat and / or mass transfer effects.

[0079] The heat transfer effect is measured as the ratio of the actual heat transfer between the gas flow and the particle flow to the maximum theoretical heat transfer between the gas flow and the particle flow. The mass transfer effect is measured as the ratio of the actual mass transfer of the chemical substance between the gas flow and the particle flow to the maximum theoretical mass transfer of the chemical substance.

[0080] The gas-particle processor may be configured to obtain an average residence time ranging from 0.1 to 10 seconds for one pass of the particle flow.

[0081] The average residence time can be achieved by controlling the percentage of separator protrusion in the chamber. Separator protrusion is defined by the following formula:

[0082]

[0083] The mean residence time can be controlled by designing the gas-particle processor to have a desired clearance angle.

[0084] It is desirable to minimize the variation in particle residence time to optimize control of the contact between the particle stream and the gas stream. This enables more precise control of particle-related parameters such as particle temperature and particle dryness. The variation in particle residence time can be measured using the dimensionless variance of the residence time.

[0085] The dimensionless variance of the particle residence time can be defined by either of the following equations:

[0086] (i)

[0087] (ii)

[0088] Where σ is the standard deviation, t ris the average / mean residence time.

[0089] The curtain of particle flow can reduce the dimensionless variance of the particle residence time by at least 5%, typically by at least 10%, more typically by at least 15%, and even more typically by at least 20%, compared to a curtain of particle flow formed in a gas-particle processor without a separator.

[0090] For the sprayable particles defined by the Geldart particle classification, the curtain of the particle stream can have a dimensionless variance of residence time of less than 0.00078, typically less than 0.00070, more typically less than 0.00067, and even more typically less than 0.00065. Typically, the sprayable particles have an average diameter of at least 1 mm and a mass of at least 1,000 kg / m 3 of particle density.

[0091] Applicants have recognized that the percentage of protrusion of the separator (relative to the clearance angle) is a factor that affects one or more of the residence time, effective altitude factor (straightness of airflow), and maximum horizontal flight of the accelerated air.

[0092] A higher separator protrusion percentage means that the separator extends at least partially across the length of the particle inlet or feeder. This increases the total surface of the curtain by increasing the trajectory of the curtain through the processor.

[0093] Airflow straightness can be measured by the particle curtain effective height factor. Improved flow straightness can be achieved by allowing the accelerated air to flow as horizontally as possible using a separator with a high percentage of protrusion. A higher percentage of protrusion can mitigate the effects of the accelerated air falling vertically upstream of the curtain.

[0094] The gas-particle processor can be configured with a range of 1 to 50 L / s / m 2 , suitably 1 to 10 L / s / m 2 The volumetric velocity is defined as the volumetric flow rate of pellets through a pellet feeder divided by the feeder's footprint.

[0095] The volume velocity can be defined by the following formula, where m s is the mass flow rate of the particle flow, ρ s is the particle density of the granular flow, f l is the length of the pellet feeder, A feed is the area of ​​the particle feeder, V s is the volume flow rate of the particle flow, and W is the width of the chamber:

[0096]

[0097] At least 50% of the particles in the curtain may have a porosity defined by the volume velocity. Suitably, at least 60% of the particles in the curtain have a porosity defined by the volume velocity. More suitably, at least 80% of the particles in the curtain have a porosity defined by the volume velocity. Still more suitably, at least 90% of the particles in the curtain have a porosity defined by the volume velocity.

[0098] The chamber may include a processing region having a height measured from a bottom of the processor to the separator.

[0099] The chamber may have a length greater than its height. Suitably, the chamber is a horizontal duct. More suitably, the horizontal duct has a rectangular cross-section.

[0100] The chamber may comprise a plurality of modular components. Suitably, each module comprises a particle inlet. More suitably, each module comprises a particle outlet. This allows the gas-particle processor to be scaled up or down as required by connecting or disconnecting the necessary number of modules.

[0101] Applicants have recognized that a bi-directional cross-flow modular system can increase the compactness of a gas-particle processor, particularly for taller contact ducts.

[0102] The bidirectional cross-flow module system may include a single pipeline with multiple separators arranged at both ends of the pipeline. Suitably, particles are introduced from the top of the pipeline and discharged from the bottom of the pipeline. More suitably, particles are introduced into the pipeline from an inlet located at the top wall of the pipeline, and particles leave the pipeline from an outlet located at the bottom wall of the pipeline. The bidirectional cross-flow module system may include a multi-stage operation with multiple curtains.

[0103] The bi-directional cross-flow modular system may include using a different gas for each cross-flow gas stream.

[0104] The bidirectional cross-flow module system may include permeable walls, or honeycombs, or meshes to separate the airflows. This prevents or minimizes interaction between the airflows.

[0105] The gas-particle processor may be configured to coat at least some of the particles of the particle stream with a coating. The coating may be in the form of a liquid and / or a powder.

[0106] Suitably, the gas-particle processor may include a particle coater to coat the particles with a coating. The particle coating device may be integrated with a feed device of the processor. Suitably, the particle coating device may be a sprayer.

[0107] In some embodiments, the particles may be coated with a coating before entering the chamber. The coated particles may then be dried by or reacted with the gas flow.

[0108] The particle feeder may be configured to introduce a stream of particles into the air stream in a substantially vertical direction. Typically, the particle feeder is configured to deliver particles downwardly into the air stream.

[0109] The particle feeder may be configured to deliver particles into the chamber to optimize the uniformity of the curtain(s) formed in the chamber. Typically, the particle feeder is configured to deliver particles into the chamber at a predetermined porosity.

[0110] The gas-particle processor may be configured to form a curtain of particles, wherein at least 50% of the curtain has a porosity of at least 0.995. The particle feeder may be configured to deliver particles into the chamber to form a curtain of particles, wherein at least 50% of the curtain has a porosity of at least 0.995.

[0111] The particle feeder may include a cassette configured to accommodate one or more characteristics of the particles, such as shape, size, surface morphology, to optimize the uniformity of the curtain(s) formed in the chamber. Typically, the cassette includes a grid that allows the particles to fall and minimizes agglomeration or aggregation of the particles. More typically, the cassette is removable and interchangeable, depending on the characteristics of the particles.

[0112] The particle feeder may be configured to control the flow rate of particles delivered to the chamber. Typically, the particle feeder comprises one or more plates arranged at a predetermined spacing from each other to achieve a desired flow rate.

[0113] The number of plates may be selected to improve the distribution of particles delivered into the chamber.

[0114] The particle feeder may be in fluid communication with the one or more particle inlets to deliver particles into the chamber. Suitably, the particle feeder is connected to the one or more particle inlets to deliver particles into the chamber.

[0115] The particle feeder may be configured to control one or both of a volumetric flow rate and a mass flow rate of particles delivered to the particle inlet. Suitably, the particle feeder is connected to a conveyor or a compressor so as to deliver particles to the particle inlet at a predetermined rate.

[0116] The particle feeder or particle inlet may include a mesh. The mesh may improve the distribution of particles fed into the chamber and reduce agglomeration or clumping of particles.

[0117] The particle feeder may have a length of at least 0.05 m, typically ranging from 0.05 to 1 m.

[0118] The gas-particle processor may include a pressure-driven device located downstream of the particle feeder to pull the accelerated gas through the top of the chamber and provide a pressure gradient to mitigate the induced vertical flow of the gas in the direction of the curtain of falling particles. The pressure-driven device may be a fan, a blower, an injector, an ejector, or a flow straightener. In one embodiment, the pressure-driven device is a barrel fan.

[0119] The downstream fan can be configured to allow the gas to pass horizontally first over the leading edge and then the trailing edge. The trailing edge of the curtain typically contains finer / smaller particles compared to the leading edge of the curtain which typically contains coarser / larger particles (which are typically heavier). This ensures that the fan effectively increases the velocity of the accelerating gas and mitigates induced downdrafts.

[0120] Increasing the accelerating gas flow may counteract the downward momentum transfer of the particle. Doing so allows the gas flow profile to remain as horizontal as possible relative to the overall downward direction of the particle. Furthermore, by allowing the accelerating gas profile to remain as horizontal as possible, it mitigates the ability of the accelerating gas to push the main gas flow downward, which reduces the horizontal nature of the main gas. It may also mitigate the formation of vortices.

[0121] The present invention also provides a method for contacting a particle flow with an air flow in a chamber, comprising:

[0122] (i) introducing an airflow into the chamber, at least a portion of the airflow forming an accelerating airflow and a main airflow in the chamber, wherein the accelerating airflow has a higher average velocity than the main airflow; and

[0123] (ii) introducing a particle stream into the air stream and forming a curtain of particle stream having an upstream edge and a downstream edge

[0124] Suitably, the method involves contacting the particle stream with the gas stream using the aforementioned gas-particle processor.

[0125] The term "contacting" is understood herein to include drying or reacting the particles using a gas stream.

[0126] The method may include directing a flow of gas into the chamber in a substantially horizontal direction.

[0127] The method may include directing the airflow into a channel defined at a lower edge thereof by a separator such that an accelerated airflow is formed above the separator.

[0128] The method may include directing the airflow into a channel defined at a lower edge thereof by a separator to maintain different velocities of the accelerating airflow and the main airflow.

[0129] The method may comprise controlling the speeds of the main airflow and the acceleration airflow to be at a speed ratio in the range from 1 to 10, suitably 1 to 6, more suitably 1 to 3.

[0130] The speed ratio is defined as the ratio of the speed of the accelerating airflow to the speed of the main airflow. The method may comprise directing a plurality of airflows into the chamber. Suitably, the method comprises directing the plurality of airflows into the chamber in opposite directions. More suitably, the method comprises controlling the direction of the airflows so that the direction of the airflows alternates along the height of the chamber.

[0131] The method may include directing a plurality of air streams to respective separators, which will form a plurality of pairs of accelerating air streams and main air streams.

[0132] The method may include controlling one or more of the gas flow velocity, the particle flow velocity, the location and size of the separator, and the chamber dimensions so that the dimensionless variance of the particle residence time of the curtain of particle flow is reduced by at least 5% compared to a particle flow curtain formed in a gas-particle processor without the separator.

[0133] The method may include introducing the particle stream into the airflow in a substantially vertical orientation. The method may include introducing the particle stream into an accelerating airflow. Typically, the method includes introducing the particle stream in a cross-flow manner with the accelerating airflow. It is believed that maintaining a horizontal accelerating airflow maximizes the total surface area of ​​the curtain exposed to the airflow.

[0134] The method may include controlling the primary airflow and accelerating the airflow velocity to improve momentum transfer from the airflow to the particle flow.

[0135] The method may include introducing the particle stream into the gas stream at an angle between the particle stream and a horizontal component of the gas stream that is greater than 20 degrees, typically ranging from 60 to 90 degrees, and more typically ranging from 85 to 90 degrees.

[0136] The method may include maintaining atmospheric pressure within the chamber.

[0137] The method may include maintaining a pressure within the chamber equal to a pressure at the source of the particle flow.

[0138] The method may include introducing positive pressure into the accelerating airflow and increasing the velocity of the accelerating airflow.

[0139] The method may include using a pressure driven device located downstream of the particle flow inlet to pull the accelerated air through the top of the chamber. The pressure driven device may be a fan, blower, injector, ejector or flow straightener.

[0140] The method may include maintaining a curtain of particles wherein at least 50% of the curtain has a porosity of at least 0.995. The volume velocity of the curtain may be controlled to range from 1 to 50 L / s / m 2 This allows the majority of particles in the particle flow to be unimpeded by neighboring particles in the particle flow.

[0141] The volume velocity is defined by the following formula, where ms is the mass flow rate of the particle flow, ρ s is the particle density of the granular flow, f l is the length of the pellet feeder, A feed is the area of ​​the particle feeder, V s is the volume flow rate of the particle flow, and W is the width of the chamber:

[0142]

[0143] The method may include coating at least a portion of the particles of the particle stream with a coating.

[0144] The coating may be in liquid and / or powder form.

[0145] The method may include coating the particles with the coating using a particle coating apparatus.

[0146] The particle coating device may be a sprayer.

[0147] The method may include coating the particles with a coating prior to entering the chamber.

[0148] The method may include forming a processing region having a height measured from a bottom of the chamber to the separator that is equal to a height of the separator.

[0149] The method may include achieving straightness of the airflow behind the first curtain. The straightness of the airflow may be measured by an effective height factor defined by the following formula:

[0150] Effective height factor = height of 90% of the primary airflow in the treatment area / height of the treatment area.

[0151] The effective height factor may have a value greater than 0.50, and suitably is between 0.5 and 0.9.

[0152] The method may include controlling one or more of the gas flow velocity, particle flow velocity, position and size of the separator, and chamber dimensions such that less than 10% by weight of the particle flow contacts the separator.

[0153] The method may include achieving an average residence time ranging from 0.1 to 10 seconds.

[0154] This average residence time can be achieved by controlling the percentage of separator headroom and any one or more of particle volume velocity, velocity ratio, and particle type.The percentage of separator headroom can be up to 100%, and typically ranges from 25% to less than 100%.

[0155] The particle size range of the particles is 50 to 10,000 microns. The applicant has observed that particles with a size less than 50 microns may experience problems with particle cohesion. For these particles, the increase in surface area per kilogram of particles may seriously inhibit the flow straightness of the main airflow behind the curtain in a multi-stage system compared to larger particles (e.g., greater than 10,000 microns). This is because larger particles are too heavy and may fall through the main airflow too quickly to produce effective cross-flow. The cross-sectional aspect ratio of the chamber may be greater than or equal to 1. The residence time of the falling particles can be increased by maximizing the falling height of the particles over the cross-sectional area of ​​the chamber. The cross-sectional aspect ratio may be less than 1 to increase the width of the chamber and the amount of feed introduced into the chamber, while using other parameters (such as one or more of the volume velocity, velocity ratio, separator protrusion percentage, and particle type) to increase the residence time. BRIEF DESCRIPTION OF THE DRAWINGS

[0156] The present invention will now be further described, by way of example only, with reference to the accompanying drawings, in which:

[0157] Figure 1 is a schematic diagram of an embodiment of a gas-particle processor of the present invention in a first curtain state.

[0158] Figure 2 is a schematic diagram of an embodiment of a gas-particle processor of the present invention in a second curtain state.

[0159] Figure 3 is a schematic diagram of an embodiment of a gas-particle processor of the present invention including two curtains.

[0160] Figure 4 is a schematic diagram of an embodiment of a gas-particle processor of the present invention, which includes a thin film coating drying process.

[0161] Figure 5 is a schematic diagram of an embodiment of the gas-particle processor of the present invention, which includes a thin film coating and drying process of a multi-stage system.

[0162] Figure 6 is a schematic diagram of an embodiment of the gas-particle processor of the present invention, which includes a thin film coating and drying process of a continuous multi-stage system.

[0163] Figure 7 is a schematic diagram of an embodiment of the gas-particle processor of the present invention, which includes a thin film coating drying process of a continuous multi-stage system in a single pipeline.

[0164] Figure 8 is a schematic diagram of an embodiment of a gas-particle processor of the present invention, which includes multiple fans to maintain a volume flow rate of accelerated air.

[0165] Fig. 9is a perspective view of a cassette of the particle feeder of the present invention.

[0166] Fig.10 Yes Fig. 9 A cross-sectional view of a box of a particle feeder of the present invention.

[0167] Fig.11 is a schematic diagram of an embodiment of a gas-particle processor and test apparatus of the present invention.

[0168] Fig.12 is a CFD modeling diagram of a gas-particle processor without a separator.

[0169] Fig.13 is a CFD modeling diagram of the gas-particle processor with an accelerating air height of 50 mm and a separator protrusion of 0%.

[0170] Fig.14 is a CFD modeling diagram of the gas-particle processor with an accelerating air height of 75 mm and a separator protrusion of 0%.

[0171] Fig.15 is a CFD modeling diagram of a gas-particle processor with an accelerating air height of 75 mm and a separator protrusion of 60%.

[0172] Fig.16 is a CFD modeling diagram of the gas-particle processor with an accelerating air height of 75 mm and a separator protrusion of 100%.

[0173] Fig.17 is a CFD modeling diagram of a gas-particle processor with an accelerating air height of 100 mm and a separator protrusion of 0%.

[0174] Fig.18 is a CFD modeling diagram of a gas-particle processor with an accelerating air height of 100 mm and a separator protrusion of 20%.

[0175] Fig.19 is a CFD modeling diagram of a gas-particle processor with an accelerating air height of 100 mm and a separator protrusion of 60%.

[0176] Fig. 20 is a CFD modeling diagram of a gas-particle processor with an accelerating air height of 100 mm and a separator protrusion of 100%.

[0177] Fig.21 is a CFD modeling diagram of the gas-particle processor with an accelerating air height of 200 mm and a separator protrusion of 0%.

[0178] Fig. 22is a CFD modeling diagram of a gas-particle processor with an accelerating air height of 200 mm and a separator protrusion of 60%.

[0179] Fig.23 is a CFD modeling diagram of a gas-particle processor with an accelerating air height of 200 mm and a separator protrusion of 80%.

[0180] Fig.24 is a graph of heat load versus separator protrusion percentage at different accelerating air heights during the experimental CFD simulation work.

[0181] Fig.25 is a graph of the average residence time versus separator protrusion percentage at different accelerating air heights during the experimental CFD simulation work.

[0182] Fig.26 is a graph of level flight versus separator protrusion percentage at different accelerating air altitudes during the experimental CFD simulation work.

[0183] Fig. 27 is a graph of the effective curtain height (stream straightness) versus separator protrusion percentage at different accelerating air heights during the experimental CFD simulation work.

[0184] Fig.28 is a graph of the standard deviation residence time versus separator protrusion percentage at different accelerating air heights during the experimental CFD simulation work.

[0185] Fig.29 is a schematic diagram of an embodiment of a gas-particle processor of the present invention comprising a bidirectional cross-flow modular unit for a single particle curtain.

[0186] Fig.30 is a schematic diagram of an embodiment of a gas-particle processor of the present invention comprising a bidirectional cross-flow modular unit for a single particle curtain having permeable walls.

[0187] Fig.31 is a schematic diagram of the experimental setup of the bidirectional cross-flow system during the experimental CFD simulation work.

[0188] Fig.32 is a CFD modeling diagram of Design 1 simulated during Experiment 2.

[0189] Fig.33 is a CFD modeling diagram of Design 2 simulated during Experiment 2.

[0190] Fig.34 This is a CFD modeling diagram of Design 3 simulated during Experiment 2.

[0191] Fig.35Schematic diagram of the gap angle between the separator and the particle inlet in the gas-particle processor of the present invention.

[0192] Fig.36 Contains graphs showing the relationship between the slip velocity of Persian clover seeds in contact with air and the heat and mass transfer coefficients.

[0193] Fig.37 : Graph showing the slip velocity distribution for a single curtain with and without a separator.

[0194] Fig.38 is a CFD modeling plot generated during Experiment 3 for a single curtain embodiment of the present invention without a separator.

[0195] Fig.39 is a CFD modeling plot generated during Experiment 3 for a single curtain embodiment of the present invention with a separator.

[0196] Fig.40 is a CFD modeling plot generated during Experiment 3 for a single curtain embodiment of the present invention having a separator and a pressure drive.

[0197] Fig.41 is a CFD modeling plot generated during Experiment 4 for a multiple curtain embodiment of the present invention without separators and pressure drive.

[0198] Fig.42 is a graph showing the slip velocity distribution of the curtain 1 without a separator.

[0199] Fig.43 is a graph showing the slip velocity distribution of the curtain 2 without a separator.

[0200] Fig.44 is a CFD modeling diagram of the double curtain system with particle flow and air flow lines according to Design 1 of Experiment 4.

[0201] Fig.45 4 is a graph showing the sliding velocity distribution of the curtain 1 of the design 1 according to the experiment 4.

[0202] Fig.46 4 is a graph showing the sliding velocity distribution of the curtain 2 of Design 1 according to Experiment 4.

[0203] Fig.47 This is a CFD modeling diagram of the double curtain system with particle flow and air flow lines according to Design 2 of Experiment 4.

[0204] Fig.48 4 is a graph showing the sliding velocity distribution of the curtain 1 according to the design 2 of the experiment 4.

[0205] Fig.494 is a graph showing the sliding velocity distribution of the curtain 2 according to Design 2 of Experiment 4.

[0206] Fig.50 is a schematic diagram showing the leading and trailing edges of a particle curtain. DETAILED DESCRIPTION

[0207] Figure 1 and Figure 2 One form of a gas-particle processor is shown. The processor 10 includes a chamber 12 having a first end 14, an opposite second end 16, and top and bottom walls 18, 20 extending between the first and second ends. The second end is located on the opposite side of the first end, and the side wall portions extend generally horizontally, thereby defining a horizontally oriented chamber. A separator in the form of a tongue 22 extends from the first end 14 of the chamber.

[0208] The chamber 12 has an array of particle inlets 24, through which particles are introduced into the chamber. Solid particles can be fed into each inlet by any type of particle feeder. The feeder can be configured to introduce particles into the chamber so that they fall or accelerate into the chamber under gravity acceleration. The inlet or feeder can include a screen, a filter screen, a grid, a mesh, etc., through which particles are introduced into the chamber. Suitably, the screen, the filter screen, the grid or the mesh are deployed in an embodiment in which particles are introduced into the chamber by free fall (i.e., by gravity). The purpose of the screen, the filter screen, the grid or the mesh is to reduce the agglomeration or agglomeration of particles, and before the particles are introduced into the chamber, the particle flow is evenly distributed on the feeder or the particle inlet, and the mass flow rate of the particles is set.

[0209] The particle inlet 24 is located on the top wall 18 of the chamber. The outlet of the feeder communicates with and / or coexists with the particle inlet 24. The processor is configured and operated so that particles fed through each particle inlet produce independent and discrete particle flows from the top wall to the bottom wall portion.

[0210] Fig.10 An embodiment of a particle feeder 200 is shown, which includes a housing 210 having a particle inlet 24. A cassette 212 (see Fig. 9 ) is positioned at the particle inlet 24.

[0211] Box 212 includes a plurality of right angle plates 214 spaced apart according to the relative particle size of the particles and the particle flow rate required for the distribution. The number of plates is configured to produce a uniform distribution of particles falling under gravity, and the total spacing at the particle inlet 24 produces the horizontal size of the particle curtain.

[0212] It is believed that the spacing between the plates provides the greatest resistance to the particles because the particles will slide along the right-angle bend before falling vertically, while the lateral vibration of the particle feeder housing 210 (with particles above and around it) allows the particles to pass horizontally through the spacing and then fall vertically. Therefore, the flow rate for a specific particle size and distribution is controlled by the spacing of the plates relative to the particle size and shape and the feeder housing 210 vibration (frequency and amplitude). The right-angle plates 214 are designed to prevent the particle flow from being transmitted toward the center of the horizontal dimension by creating different horizontal distances for the particles to travel, thereby producing a uniform distribution of vertically flowing particles.

[0213] The chamber 12 also has an array of particle outlets 26 through which particles exit the chamber. The particle outlets are formed on the bottom wall 20 opposite to where the inlets are located. The particle outlets 26 are opposite to, but offset from, the corresponding particle inlets 24. Since the particles have some horizontal movement as they pass through the chamber, each outlet is located downstream of its corresponding inlet. The discrete particle streams flowing out of the corresponding particle inlet 24 leave the chamber through a specific particle outlet. For example, particles flowing out of the first particle inlet 24 only leave the chamber through the first particle outlet 26.

[0214] exist Figure 1 In the first particle curtain state shown, the particle outlet 26 is located on the bottom wall 20 opposite to the particle inlet 24. Figure 2 In the second particle curtain state shown, the particle inlet 25 is located on the top wall 18 of the chamber 12. Figure 1 In contrast, particles are introduced into the chamber through particle inlet 25 and are induced to flow substantially horizontally, rather than vertically.

[0215] As the particles fall through the gas in the processor 10, heat and / or mass exchange and / or chemical reactions may occur between the particle stream and the gas stream. At any time within the chamber 12, the particle streams within the chamber are substantially unmixed.

[0216] Since the processor is able to operate multiple discrete particle streams, it can act as a "multi-stage" processor. A multi-stage processor can be configured to receive two or more fresh feeds. A multi-stage processor can include multiple particle inlets and outlets, where each particle inlet is paired with a dedicated outlet. This provides the benefit of reduced space and cost requirements compared to having multiple processors to perform the same amount of single particle stream processing.

[0217] The array of particle inlets and outlets may be configured to circulate particles through chamber 12. In one form, such circulation may be from each outlet to its corresponding inlet. In another embodiment, first particle outlet 46 is connected to second particle inlet 48 by a conduit, and second particle outlet 50 is connected to third particle inlet 52 by another conduit, so that particles flow between the connected outlets and inlets. Figure 5 One form of this embodiment is shown. In this embodiment, the first particle inlet 44 defines the initial inlet of particles to the chamber 12, while the third particle outlet 54 defines the final outlet of particles from the chamber 12 and out of the processor. In one variation, the system can be semi-closed, so that some particles leave the processor at the third particle outlet, but some particles are recycled to the first particle inlet, and supplemental particles are added to compensate for particles that have left the system.

[0218] like Fig.11 The chamber 95 shown also includes a main gas inlet 100 located at the first end 97 and a gas outlet 118 located at the second end 99 of the chamber 95, so that during operation of the processor 10, gas flows between the inlet and the outlet along the length of the chamber. In order to provide and direct this gas flow, the processor 10 may include a main gas feeder 98, which feeds gas to the main gas inlet 100 of the chamber. The gas feeder is in the form of a pump, a compressor, a blower, etc. The chamber also includes an acceleration gas inlet 106. The processor may include an acceleration gas feeder 104, which may be in the form of a fan to provide an acceleration gas 102. The acceleration gas flow and the main gas flow are separated in the chamber 95 by a tongue 108. Solid particles are discharged from the hopper 110 into the particle inlet 112 of the chamber. The corresponding particle outlet 114 of the chamber is connected to the hopper 116 to capture the exiting particle flow. The main gas flow leaves the chamber at the gas outlet 118. The processor may include an additional hopper 120 downstream of the chamber to collect any residual particles in the exiting gas, and an air extraction fan 122 to direct the air flow.

[0219] It is to be understood that the processor may include more or fewer particle inlets and outlets. In one variation, the processor may include a single particle outlet formed in the bottom of the chamber, the outlet receiving all particles entering the chamber through the inlet.

[0220] Figure 3 Another form of a gas-particle processor is shown in FIG. 1 , in which a plurality of tongues 28 are located in the chamber and are located upstream and downstream of particle inlets 30 and 32. One gas inlet may be used to introduce the gas into the chamber as a single stream which is then separated into an accelerating gas stream and a main gas stream using a separator, or dedicated gas inlets may be used to introduce separate accelerating gas streams and main gas streams into the chamber.

[0221] One benefit of having an accelerating airflow with a higher velocity than the main airflow is that heat and / or mass transfer can be optimized by maximizing the slip velocity. This can be achieved by controlling the acceleration and main airflow profiles to be as horizontal as possible, as can be seen in the following formula, where Y slip The term provides the most significant contribution to the slip velocity:

[0222]

[0223] x is the horizontal dimension of the chamber (eg, length), y is the vertical dimension of the chamber (eg, height), and z is the width dimension of the chamber.

[0224] When the gas flow line is perpendicular to the particle flow, that is, when the particle x-term is as close to 0 as possible and the gas x-velocity is increased, X slip maximize.

[0225] When the vertical downward velocity of the airflow line is as close to 0 as possible and the particles fall under the action of gravity, Y slip maximize.

[0226] The Z term is considered negligible.

[0227] Two curtains are formed in the chamber of the processor. Fig.50 The leading and trailing edges of the particle curtains are shown. Particles in the first curtain exit the chamber at particle outlet 31. Particles exiting the second curtain at particle outlet 33 can be recycled and reintroduced into the chamber and the first curtain at particle inlet 30. The presence of multiple tongues reduces the downward force on the main airflow 34. Figure 1 This allows a larger portion of the primary airflow to maintain an effective height factor in comparison. In another embodiment, the pressure gradient along the path of the accelerating airflow may be maintained by inserting one or more fans, blowers, ejectors, flow straighteners or other pressure driven devices near the plurality of tongues.

[0228] Upstream and downstream flaps are used in conjunction with fans, blowers, flow straighteners or other pressure driven devices to increase the velocity of the accelerating airflow, which helps to mitigate the downward drag imposed by the particles on the accelerating and primary airflow profiles.

[0229] Applicants have found that without upstream and downstream flaps, it is not possible to re-accelerate the velocity of the overall airflow. Applicants have also performed simulations to show that in some cases, 50% less total airflow is required for a curtain with flaps to land in the same position as a curtain without flaps.

[0230] Figure 4-7 Another form of a gas-particle processor is shown, including a spray chamber 36 that coats solid particles with a layer of liquid before the particles are introduced into the chamber. Depending on the desired final form of the particles, the gas can be used to dry or react with the coated particles. In these figures, moisture is removed from the particles and enters the gas stream, forming a moist exhaust gas stream.

[0231] Figure 4 A cross-flow contacting apparatus for drying a wet film coating on a particle is shown. The apparatus involves heat and mass transfer as there is heating and evaporation of the coating as well as heating of the particle.

[0232] The particles are fed into a spray chamber 36 where a nozzle sprays droplets onto each individual particle, thereby forming a uniform film coating on each particle. When the particles with a wet coating leave the spray chamber 36, they enter the chamber 12. A horizontal drying gas 40 is supplied to the chamber 12. The horizontal drying gas comprises an accelerating gas stream and a main gas stream. Each of these gas streams can be introduced into the chamber alone or formed in the chamber using a separator 28. First, the coated particles contact the accelerating gas, which provides horizontal acceleration to the particles. The particles then fall into the main gas stream, where most of the drying occurs. The coating on each particle is dried so that the particles do not gather together or deform at the particle outlet 38. Different coatings will have different drying requirements to achieve an acceptable drying level in the coating. The film coating on each particle allows the moisture in the coating to be dried quickly in the time it takes for the particles to fall through the processor.

[0233] The residence time of each particle is important because the drying kinetics of the coating determine how long the wet coated particles must be in contact with the hot gas to dry to the extent required to avoid agglomeration or deformation. The drying gas will remove moisture from the coating due to the mass transfer of water from the coating to the horizontal drying gas. The relative humidity in the outlet gas (humid gas 42) varies depending on the mass fraction of water in the outlet gas and the outlet temperature. Excess moisture in the outlet gas is removed downstream of the curtain. Excess moisture can be removed, recycled or integrated into the gas-particle process for heat recovery. The resulting dry gas can be recycled and used as the inlet gas flow for drying the first curtain, thus forming a closed loop.

[0234] Figure 5 Shows Figure 4 An embodiment of the present invention is optimized for a greater particle throughput for the same flow of horizontal drying gas 40. In this embodiment, the particles can be dried in a number of consecutive layers n in the same pipeline. In use, the particles enter the spray chamber 36 to coat the particles, and then they enter the chamber 12 through the first particle inlet 44 to form a particle curtain. Water evaporates from the coating of the particles in the curtain to a predetermined level, and the particles leave through the first particle outlet 46. The particles are then directed to another spray chamber 36 for a second coating. The coated particles then enter the second particle inlet 48 to form a second particle curtain, where the second coating is dried. The second particle curtain leaves the chamber through the second particle outlet 50 and is directed to another spray chamber 36. The coating process is repeated to form a third coating on the particles before the particles re-enter the chamber through the third particle inlet 52. The particles are dried in the chamber to produce particles with three layers of coating, which leave through the particle outlet 54.

[0235] The beneficial effects of this arrangement include: i) better utilization of the energy required to heat the gas to the temperature required for drying (yielding higher particle throughput per kilowatt-hour consumed); ii) a more compact design, as this arrangement requires only one pipeline to dry multiple layers; iii) quality control of each layer ensures that each layer is dried before entering the next coating and drying stage; and iv) controllability of the coating drying dynamics can lead to an optimized process for quality controlled product versus energy consumption.

[0236] exist Figure 6 In another embodiment shown, Figure 5 The multi-stage system operates as a continuous process, where each coating stage takes place in a separate pipe, which applies and dries each layer of the coating. Figure 5 The embodiment of the present invention is similar, the particle outlet of the previous stage becomes the particle inlet of the next coating stage. However, in this embodiment, each pipeline is stacked vertically to allow gravity to accelerate the particles through the continuous stage. The first flow of the horizontal dry gas 41 is directed to the first pipeline 19. The horizontal dry gas 41 forms an accelerated airflow and a main airflow in the chamber, wherein the two flows are separated by a separator. The particles enter the spray chamber 36 and are coated with a layer before entering the chamber through the particle inlet 56. The airflow removes water from the coating so that the outflow gas (wet airflow 43) contains the mass fraction of moisture from the coating. The coated particles leave from the first pipeline through the particle outlet 58 and are directed to another spray chamber 36. Then, the wet coated particles leaving the spray chamber enter the second pipeline 21 through the particle inlet 60 and dry the second coating using the horizontal dry airflow 45. The particles with the dried second coating leave from the pipeline through the particle outlet 62 and enter another spray chamber for the third coating. The wet coated particles enter the third pipeline 23 through the particle inlet 64, where the third layer of coating is dried using the horizontal dry gas 49. The dried granules exit the third conduit through granule outlet 66 to form the final product.

[0237] An advantageous effect of such an embodiment is that, since each coating is present in a different conduit, there is less potential for contamination. On the other hand, such a system is less compact and requires higher capital costs (e.g., higher fan capital costs and energy consumption) for the same particle throughput. Figure 7 Shows Figure 5Alternative multi-stage embodiment of the embodiment. Three consecutive coating and drying stages are run as a continuous process in a single chamber or pipeline. The horizontal drying gas flows through the chamber 12 with three particle inlets. As the gas moves horizontally through the chamber, it becomes colder and more humid. The solid particles are coated in the spray chamber 36 and then enter the chamber through the particle inlet 68 farthest from the horizontal drying gas inlet. The coated particles interact with the coldest and most moisture-rich gas and are dried. The particles from the first particle outlet 70 are directed to another spray chamber and coated. The coated particles enter the chamber from the second particle inlet 72 located between the horizontal drying gas inlet and the first particle inlet 68. The coated particles are dried using the horizontal drying gas flow and leave the chamber from the particle outlet 74. The particles at the particle outlet 74 are directed to another spray chamber for a third coating. The coated particles enter the chamber from the third particle inlet 76 and interact with the horizontal drying gas flow when it is hottest and driest. The particles with three layers of coating are dried and leave at the third particle outlet 78 to produce the final product. The system is optimized for temperature and concentration driving forces. However, the system can be configured to control relative humidity, which may prevent effective drying in subsequent curtains.

[0238] During operation, gas flows through the chamber 12 at a streamline (first) velocity, which is generally linear in the horizontal direction.

[0239] The airflow 13 is directed to the tongue 22 so that the airflow is divided into an accelerating airflow 15 and a main airflow 17. Figure 1 As shown. The ratio of the acceleration airflow velocity to the main airflow velocity ranges from 1-6. It is believed that a vortex is formed in the space above and inside the processing area of ​​the processor. The processing area is defined as the area occupied by the main airflow between the bottom of the processor and the tongue.

[0240] Each particle stream is introduced into the chamber at a second velocity and at a feed angle relative to the direction of the streamline velocity of the gas.

[0241] The gas flow and each particle flow have respective first and second mass flow rates through the chamber. Preferably, during operation of the processor, one or both of these mass flow rates are controlled to obtain desired particle curtain properties, such as straightness of the gas flow, porosity, effective surface area per unit volume of particles in the curtain, and particle residence time.

[0242] The gas-particle processor may have multiple inlets for introducing multiple particle streams into the chamber and corresponding outlets. Each particle stream may have a different mass flow rate and / or different types of particles.

[0243] Importantly, most particles in the particle stream are not obstructed by adjacent particles in the particle stream. The increased access of the gas to the particle surface thus improves heat and / or mass transfer and / or chemical reactions, for example, to promote drying of particles in the particle stream.

[0244] Figure 8 Another embodiment of the present invention is shown. A first tongue 90 is located in the chamber at the entrance of the accelerated air 82 and main air 84 streams. A plurality of tongues 92, 94 are located downstream of the first tongue 90 and in line with the first tongue 90. A plurality of cylindrical fans 88 are located near the particle inlets 86 and 87. In this embodiment, the fan 88 generates a suction force that pulls the accelerated air flow through the first curtain so that the accelerated air flow is directed horizontally to the downstream tongue 92. Instead of the accelerated air flow falling vertically when the particles interact with the main air flow, using the fan to "pull" the accelerated air flow will form a well-distributed particle curtain. This also retains the accelerated air flow characteristics of the downstream curtain because the fan can maintain the volume flow rate of the accelerated air flow.

[0245] Fig.29 Another embodiment of the present invention is shown. Particles are introduced into the pipeline of the module unit through a particle inlet located at the top wall of the pipeline. The first horizontal cross-flow gas flow is divided into an accelerating gas 1 and a main gas 1. The accelerating gas 1 enters the pipeline from an inlet located at the first end of the pipeline, in an area above the first tongue or baffle. The main gas 1 enters the pipeline from an inlet located at the first end of the pipeline, in an area below the first baffle. Particles are introduced into the accelerating gas flow 1 through the particle inlet. The particles then fall through the gaps in the first baffle and are introduced into the main gas 1, forming a particle curtain. The main gas 1 and the accelerating gas 1 leave the pipeline from a gas outlet 1 located at the second end of the pipeline, which is opposite to the first end of the pipeline.

[0246] A second horizontal cross-flow gas stream is introduced into the pipeline from an inlet located at the second end of the pipeline in the opposite direction to the first cross-flow stream. The second cross-flow gas stream is divided into an accelerating gas 2 and a main gas 2. The accelerating gas 2 enters the pipeline through a channel formed by the second baffle and the third baffle. The main gas 2 enters the pipeline in the area below the third baffle. The curtain is introduced into the accelerating gas 2 through a gap in the second baffle, which changes the direction of the curtain to the opposite direction. The curtain is then introduced into the main gas 2 through a gap in the third baffle. The particles of the curtain leave the pipeline from the particle outlet located at the bottom end of the pipeline. The main gas 2 and the accelerating gas 2 leave the pipeline from the outlet located at the first end of the pipeline. The baffle helps to protect the flow of each horizontal cross-flow gas stream from leaking into another adjacent gas stream. Pressure balance is required to balance the air pressure on the vertical path of the falling particles. When the particles move from the influence of one gas stream to the influence of another gas stream, the accelerating gas provides momentum transfer to turn the particle flow in the opposite direction. The accelerating gas also keeps the overall gas flow horizontal (mitigating induced vertical flow).

[0247] Fig.30 Further details are shown in Fig.29 Another embodiment of the present invention of the embodiment of the invention. To further prevent the separated cross-flow gas streams from interacting with each other, a permeable wall or honeycomb or grid can be used to cover the gaps between the baffles, thereby allowing particles to pass through but limiting vertical gas turbulence that may force the gas to pass through to another cross-flow gas stream below. This type of system is suitable for particles that do not agglomerate and particles that are not susceptible to mechanical stress.

[0248] Fig.35 is a schematic diagram showing the clearance angle between the separator and the particle inlet and providing the formulas defining the clearance angle and the separator protrusion percentage.

[0249] Experimental work

[0250] Experiment 1

[0251] The applicant has carried out experimental work in connection with the present invention to demonstrate that the invention can achieve a high surface area of ​​the curtain and improve the straightness of the gas flow in the gas-particle processor.

[0252] The applicant conducted two phases of experimental work:

[0253] i) a physical experimental program on a test rig that generated the VIPAC certification dataset that formed the basis for the physically validated CFD model, and

[0254] ii) Virtual experimental procedures for testing the effects of accelerating air, separators and separator protrusions.

[0255] The details of the physical experimental work are summarized below:

[0256] i. The experiments were carried out in a physical test equipment apparatus having a horizontal contactor with accelerating gas, main gas and separation partition.

[0257] ii. The experiments involved sensible heat transfer applications involving a hot air flow as the total air flow and a silica sand particle flow as the particle flow.

[0258] ii. The gas-particle processor operates in a horizontal pipe, 0.5 m high and 0.5 m wide. The height of the accelerating gas is 0.05 m.

[0259] iii. The mass flow rate of the total gas flow (including the accelerating air flow and the main gas flow) was kept constant at 0.4 kg / s. The inlet temperature of the total gas was kept constant at 132°C.

[0260] iv. The mass flow rate of the particle flow was kept constant at ~0.5 kg / s.

[0261] v. Each experiment was performed over a steady state period of 40-45 minutes.

[0262] vi. Acceleration air height is defined as the height above the separator where the acceleration air is supplied. In the experiment, the acceleration air height was 0.05m.

[0263] vii. Separator Protrusion (%) = 0 remains constant.

[0264] viii. Experiments were conducted for three different speed ratios.

[0265] ix. The heat load and heat transfer effect of each experiment were measured.

[0266] x. Experiments were conducted on a gas-particle processor with only one curtain.

[0267] xi. Each experiment was then simulated using computational fluid dynamics (CFD) modeling software. The CFD simulations were able to predict the experimental results to an acceptable level validating the modeling work.

[0268] The details of the virtual experimental work are summarized as follows:

[0269] i. The experiments were performed using computational fluid dynamics (CFD) modeling software, which was validated using physical experimental results on a test rig.

[0270] ii. The CFD modeling software simulated a specific sensible heat transfer application involving a hot air flow as the total air flow and a soda ash particle flow as the particle flow.

[0271] iii. The gas-particle processor is modeled as a horizontal pipe with a height of 1.003 m and a width of 0.5 m.

[0272] iv. The mass flow rate of the total airflow (including the accelerating airflow and the main airflow) was kept constant at 1.13 kg / s.

[0273] v. The mass flow rates of acceleration air and main air remain constant.

[0274] vi. The mass flow rate of the particle flow was kept constant at 1 kg / s.

[0275] vii. The Accelerating Air Height is defined as the height above the separator where the accelerating air is supplied.

[0276] The separator protrusion percentage is calculated using the following formula:

[0277]

[0278] ix. Simulations were performed for four different accelerating air heights and different separator protrusion percentages.

[0279] x. The change in the height of the accelerating air changes the velocity ratio of the accelerating air to the main air.

[0280] xi. One simulation was conducted without a separator. The other simulations were conducted with accelerating air heights of 50 mm, 75 mm, 100 mm, and 200 mm and accelerating air velocities of 16 m / s, 10.67 m / s, 8 m / s, and 4 m / s, respectively.

[0281] xii. The experiments were conducted on a gas-particle processor with only one curtain.

[0282] xiii. The simulated process parameters are shown in Table 1 below.

[0283] Table 1: Process parameters for CFD simulation of Experiment 1.

[0284] Contactor width(m) 0.5 Total pipeline height (m) 1.003 Separator thickness (m) 0.003 Accelerating air height (m) 0.05, 0.1, and 0.2 Main air height (m) 0.8, 0.9, and 0.95 Separator protrusion (%) 0、20、40、60、80、100 Acceleration air flow (kg / s) 0.784 Main air flow rate (kg / s) 0.35 Total air flow (kg / s) 1.13 Inlet air temperature (K) 405 Feeder length (m) 0.2 Mass flow solids (kg / s) 1 Volume velocity (mm / s) 3.9 Particle size (m) 0.00028-0.0004 (the average value of rosin Ramler is 0.00034) <![CDATA[Particle density (kg / m 3 )]]> 2540 Specific heat (J / kg.K) 1047-1769

[0285] Experiment 2

[0286] The applicant has carried out experimental work in connection with the present invention to demonstrate that the compactness of the present invention can be improved by using a bidirectional cross-flow system.

[0287] The details of the experimental work are summarized as follows:

[0288] I. The experiment was performed using computational fluid dynamics (CFD) modeling software.

[0289] II. The CFD modeling software simulates a specific sensible heat transfer application involving a hot air flow as the total air flow and a seed particle flow as the particle flow.

[0290] III. The gas-particle processor is modeled as a single pipe with a height of 5 m, a length of 1 m, and a width of 0.15 m.

[0291] IV. The pipeline is divided into two cross-flow sections, each with a height of 2.5 meters.

[0292] V. Accelerating air height is defined as the height above the separator where the accelerating air supply is located.

[0293] VI. The mass flow rate of the particle flow was kept constant at 0.3 kg / s.

[0294] VII. The simulated process parameters are shown in Table 2 below.

[0295] Table 2: Process parameters for CFD simulation of Experiment 2.

[0296]

[0297]

[0298] Experiment 3

[0299] The applicant has performed experimental work related to the present invention to demonstrate the performance differences resulting from the use of a separator and a pressure driven device to form a single particle curtain in a contactor.

[0300] The simulation used uniform 0.881 mm Persian clover seeds interacting with 15°C air at 15°C. The process parameters for Experiment 3 are shown in Table 8 below.

[0301] Table 8: Process parameters of Experiment 3.

[0302]

[0303] The same total air flow was used for both the non-separator and separator simulations, where the separator simulation simply split the same total flow into two discrete inlet airflows. Isothermal applications were performed to minimize possible bias in the results through heat transfer (i.e., gas cooling and deceleration, etc.).

[0304] Experiment 4

[0305] Applicants have conducted experimental work related to the present invention to demonstrate the performance differences resulting from the use of multiple separators and pressure-driven devices to form multiple particle curtains in a contactor.

[0306] The simulation interacted air at 15°C with two curtains consisting of 2 mm seeds at 15°C in a multi-stage system, the properties of which are shown in Table 9 below.

[0307] Table 9: Process parameters of Experiment 4.

[0308]

[0309] Both curtains have an upstream separator and a downstream separator, and both have a downstream pressure drive (fan).

[0310] Experimental Results

[0311] Experiment 1

[0312] This CFD study investigated the effect of separator protrusion on multiple process parameters including heat load. For fixed accelerating gas height and feeder length in this study, the clearance angle, package separator protrusion and acceleration zone height are inversely proportional to the separator protrusion.

[0313] The CFD simulation of the gas-particle processor without separator includes a soda ash particle stream as a particle stream that is introduced into the hot air stream. There is no separator to separate the gas flow into acceleration air and main air. See Fig.12, the airflow does not effectively move the curtain horizontally because the flow is induced vertically. Therefore, the particles move a short distance horizontally and the curtain is not well developed.

[0314] Although both the air and particle flows have identical thermal inlet characteristics, for all four accelerating air heights the amount of heat exchanged is clearly highest where the separator protrusion is maximized.

[0315] Experimental results show that higher separator protrusion percentages increase the trajectory of the curtain, which allows for a higher total curtain surface area.

[0316] The high percentage of separator protrusion also ensures that the accelerated air remains as horizontal as possible, which means that the total surface area of ​​the curtain is utilized, rather than the accelerated air "swooping" through the flow and avoiding the curtain. The swooping effect allows the accelerated air to fall through the gap between the separator and the curtain.

[0317] The highest heat loads recorded were for the example with an accelerating air height of 75 mm and a protrusion of 100%, which allowed the main air to be slightly higher than the examples with an accelerating air height of 100 mm and 200 mm, see Tables 3-5 below. Fig.24 The graph of heat load vs. protrusion percentage for the CFD examples in Figure 2 shows that for all four ramp-up air height examples, the heat load on the processor increases in proportion to the protrusion percentage. For the 50 mm ramp-up air height, the highest heat load is observed when the protrusion is 0%. The lowest heat load is observed when the protrusion is 0% at the 100 mm ramp-up air height. However, at higher protrusion percentages, the heat load increases from Fig.24 It can be seen that the lowest heat load is for the 200mm Acceleration Air Height example. At 60% protrusion, the 75mm example has the highest heat load of 65,000W, while the second highest heat load is about 64,300W for the 100mm example. The lowest heat load for the 60% protrusion occurs in the 200mm Acceleration Air Height example. At 100% protrusion, the heat load is about 67,860W for the 75mm example and 66,700W for the 100mm Acceleration Air Height. This shows that the protruding separator is a beneficial feature.

[0318] Table 3: Results of CFD simulations at 75 mm accelerating air height for different separator protrusion percentages during Experiment 1.

[0319]

[0320]

[0321] Table 4: CFD simulation results for 100 mm accelerating air height for different separator protrusion percentages during Experiment 1.

[0322]

[0323]

[0324] Table 5: CFD simulation results for 200 mm accelerating air height for different separator protrusion percentages during Experiment 1.

[0325]

[0326]

[0327] However, the separator protrusion percentage has a limit for each accelerating air height. For the 200 mm accelerating air height, particles start to hit the separator after 80% separator protrusion. For the 50 mm accelerating air height example, with higher protrusion percentages, the turbulence becomes too great and the curtain does not work in the cross flow. As a result, the simulation diverges and no useful data can be extracted. This indicates that there is an upper limit to useful protrusion length and protrusion percentage.

[0328] The experimental results show that for larger separator protrusion percentages, the average residence time is maximized, see Tables 3-5. This may be related to the reduction of the dive effect. The accelerating air has a tendency to nose-drive, and this affects the y component of the velocity, especially at the leading edge of the curtain. For larger separator protrusions, the standard deviation of the residence time also increases, but is still only ~5% of the residence time.

[0329] Fig.25 A graph of the average residence time for different percentages of protrusion is shown for the CFD example without separator and at 50mm, 75mm, 100mm and 200mm accelerating air heights. The graph shows that at 0% protrusion, the highest average residence time for the particles in the example without separator is observed. This is likely because without separators and accelerating air, the particles in the particle stream are not accelerated as they fall through the airflow. For the 50mm accelerating air height example, the second highest average residence time at 0% protrusion can be seen. For the 100mm accelerating air height example, the lowest average residence time at 0% protrusion is seen. As the percentage protrusion increases, the average residence time at the four accelerating air heights also increases. At 60% protrusion, it can be seen that the average residence time is highest at 75mm, the second highest at 100mm, and the lowest at 200mm. For the 75mm accelerating air height example, the highest average residence time at 100% protrusion can be seen on the graph.

[0330] Fig.28A graph of the standard deviation of residence time versus percentage of separator protrusion is shown for the four accelerated air height examples and the no separator example. The standard deviation of residence time in the 50 mm example increases as the percentage of protrusion increases from 0% to 40%. For the 75 mm, 100 mm, and 200 mm accelerated air height examples, the standard deviation of residence time is lower at 60% protrusion. The standard deviation of residence time at 60% protrusion is highest at 75 mm accelerated air height. For the 100 mm example, the second highest standard deviation is observed at 60% protrusion, with the 200 mm example having the lowest standard deviation of residence time. At 100% protrusion, the highest standard deviation is observed at 75 mm accelerated air height, but this is still lower than the standard deviation of the 50 mm example at 40% protrusion. The standard deviation of the 100 mm example also increases as the percentage of protrusion increases from 60% to 100%.

[0331] Fig.26 The trend of horizontal flight for the four accelerated air heights versus separator protrusion percentage can be seen in . For the 50 mm accelerated air height example, the maximum horizontal flight distance of the accelerated air at 0% protrusion is the highest, with a value of 2.5 meters. For the example without a separator, there is only one airflow in the processor and it travels the smallest horizontal distance. The second highest horizontal distance at 0% protrusion is measured for the 75 mm example, and the third highest horizontal flight is for the 200 mm example. From Fig.26 It can be seen from the graph in that as the percentage of protrusion increases from 20% to 60% and further to 100%, the horizontal flight of the accelerated air at 100 mm also increases. The shortest horizontal flight distance is seen for the 200 mm acceleration altitude. This is because the accelerated air is dispersed over a greater altitude, which reduces the speed of the accelerated air for the vertically induced air. When the accelerated air is induced more horizontally along the separator, the highest maximum horizontal flight is seen for the example of 75 mm at 100% protrusion, and the speed of the air is maintained because the air is dispersed across a smaller altitude.

[0332] Fig. 27The chart in shows the effective height of the curtain for four accelerating air heights for different percentages of separator protrusion. The effective height of the curtain, or "effective height factor," defines the straightness of the airflow in the processor. The effective height factor is defined as a measure of how much primary air flow there is in the processing area of ​​the processor. As the primary air flows through the processing area, there is a downward force on the primary air flow. For the no separator example, the effective height factor at 0% protrusion is the lowest at 0.55, the 200 mm accelerating air height example is the second highest at 0.778, and the 50 mm accelerating air height example is the highest at 0.89. As the percentage of protrusion increases from 0% to 40%, the 50 mm example has a lower effective height factor at 0.867. For the 100 mm accelerating air height example, the effective height factor is the lowest at 0.667 for the 20% protrusion. The effective height factor is 0.833 for the 60% protrusion and 0.889 for the 100% protrusion. As the percentage of protrusion increases, the effective height factor increases and airflow straightness is achieved. This demonstrates the importance of the separator in allowing a larger portion of the main gas flow to be utilized in the processing area.

[0333] The curtain with the higher separator protrusion percentage travels the farthest and has the largest curtain expansion at the bottom of the tube. This is expected, as the separator protrusion allows for better momentum transfer and more horizontal contact in the acceleration area. This is consistent with Fig.12 This is in contrast to the simulation example without a separator shown in , which induces airflow vertically and does not effectively move the curtain horizontally. This is an important consideration in utilizing duct length and affects how many curtains can be installed in a fixed duct, especially for taller ducts.

[0334] The 50 mm accelerated air height example forces the curtain to travel the farthest because the smaller height and faster speed acts as a "transition point" to turbulence, see Table 6 below. This forces the curtain to become triangular, which allows the curtain to flow more horizontally in the early stages, such as Fig.13 On the other hand, the 200 mm accelerated air height example has minimal accelerated air level flight because the velocity is smaller and distributed over a greater altitude, resulting in a more upright (vertical) initial angle, as shown in Fig.26 shown.

[0335] Table 6: CFD simulation results for 50 mm accelerating air height for different separator protrusion percentages during Experiment 1.

[0336]

[0337]

[0338] Generally, the height of the accelerating air should be minimized to maximize the height of the primary air flow. However, there will likely be a limit where the turbulence and angles are too high, which will result in a curtain that is too turbulent. Fig.13 This can be seen in the CFD graph for 50 mm accelerating air height, especially for the higher percentage separator protrusion.

[0339] Larger separator protrusion percentages affect the stream straightness metric (curtain effective height) reported by CFD. Higher separator protrusion percentages result in better stream straightness. This is expected, as allowing the accelerated air to flow as horizontally as possible will reduce the dive effect of the air and the vertical drop of the accelerated air upstream of the curtain caused by vortices. This can be seen in the Figure 12-23 See the CFD diagram shown.

[0340] For the 75 mm accelerated air height example, from Fig.14 It can be seen that the curtain shape of the processor with 0% protrusion is similar to Fig.13 The curtain shape is similar to the 50 mm example seen in . At 60% protrusion and 75 mm accelerated air height, the curtain has a larger trajectory and travels a greater distance horizontally than the example with 0% protrusion, see Fig.15 At 100% prominence, from Fig.16 It can be seen that the curtain has a good trajectory, but the turbulence in the lower area of ​​the curtain is increased.

[0341] Example of 100 mm accelerated air height with 0% protrusion produces a curtain with a small horizontal travel distance, see Fig.17 When the protrusion is 20%, the horizontal distance of the curtain movement increases, see Fig.18 Increasing the protrusion percentage of the 100 mm example to 60% shows that the accelerated air remains as horizontal as possible using the total surface area of ​​the curtain. At 100% protrusion, the accelerated air remains horizontal after its interaction with the curtain, but the particles in the curtain begin to exhibit turbulence in the lower area of ​​the curtain.

[0342] The 200 mm accelerated air height example shows that the horizontal distance of acceleration is small. At 0% protrusion, the accelerated air is initially induced vertically, see Fig.21 At higher percentages of protrusion, the straightness of the accelerating air flow is improved, e.g. Fig.23 and Fig.24 as shown in .

[0343] The percentage of separator protrusion affects the curtain volume in the pipe for two main reasons. First, the separator protrusion increases the trajectory of the curtain, resulting in increased curtain volume and surface area for a fixed pipe height. Second, the separator protrusion pushes all particles to become more horizontal and can increase turbulence of the particles. This generally results in lower surface area and volumetric heat transfer coefficient per unit volume for embodiments with one curtain.

[0344] The surface area per unit volume metric is useful in multiple curtain embodiments. However, if only one curtain is required, then the surface area per unit volume is less important than the heat load, residence time, and standard deviation of residence time in the gas-particle processor. Flow straightness also becomes more relevant for multiple curtain embodiments.

[0345] The benefits of maximizing for one curtain may not be as beneficial for multiple curtains. Before investigating multiple curtain options, the process of determining the preferred design must consider whether a single curtain configuration is feasible, as downstream flow straightness may be sacrificed if a single curtain system is a viable option. A CFD-based modeling process can facilitate the comparison of these options.

[0346] Downstream flow straightness can be controlled by fans or other pressure gradient interventions to control the continued flow of the accelerated air to the next hypothetical downstream curtain. This feature was not considered in this study, but would be considered when studying multiple curtain options.

[0347] Experiment 2

[0348] The experimental setup for bidirectional cross-flow simulation is Fig.31 Shown in.

[0349] The simulated Design 1 includes a bidirectional cross flow with a positioned gap between the two cross flow sections and the two accelerating air flows.

[0350] Design 2 simulated included a unidirectional cross flow without accelerating air.

[0351] Design 3 simulated included unidirectional cross flow with accelerating air flow and 0% separator protrusion.

[0352] The results of the simulation work using these three designs are shown in Table 7 below.

[0353] Table 7: Results of CFD simulations of bidirectional and unidirectional cross-flow systems during Experiment 2.

[0354]

[0355]

[0356] Experimental results show that using a bidirectional cross-flow system results in a 35% reduction in horizontal footprint compared to the maximum unidirectional cross-flow state.

[0357] Residence time, curtain mass, and surface area did not change significantly from bidirectional to unidirectional crossflow, as expected. However, the surface area was highest in the design with accelerated air. This allows the curtain to hold more mass for a fixed duct height.

[0358] The two-way crossflow example has the highest heat load. The one-way design can be optimized to achieve the same heat load as the two-way design, but the advantage of the two-way design is that the high heat load can be achieved in a smaller footprint. This is the advantage of the compactness of a single curtain.

[0359] Fig.32 The CFD plot of Design 1 in which a simulation using a bidirectional cross flow is shown. When the particles contact the primary air flow flowing from left to right, the curtain formed in the first cross flow section has a uniform shape. The particles then enter the second cross flow section and are introduced into the second accelerating air flow flowing in the opposite direction from right to left. The shape of the curtain is similar to that of the first cross flow section.

[0360] Fig.33 CFD plots for Design 2 using a simulation of a unidirectional cross flow without accelerating air are shown. The particle flow was initially induced vertically as in Experiment 1. Only one horizontal air flow cross-pathed with the particle flow, and the curtain formed moved horizontally for a shorter distance and had a smaller surface area than Design 1.

[0361] Fig.34 The CFD plot of Design 3 using a simulation of a unidirectional crossflow with accelerating air flow is shown in Figure 1. The separator does not protrude the length of the particle feeder or particle inlet. The curtain formed by Design 3 is Fig.33 The curtain has a larger spread than Design 2 shown in Figure 1. The curtain has a larger surface area than Design 2 and occupies the largest area of ​​the three designs.

[0362] Although the experimental work was carried out using CFD modelling software, the applicant believes that the same or similar results would be obtained if carried out in a larger scale test facility.

[0363] Modeling work performed by the applicants indicates that the experimental data for the soda ash particles tested can be generalized to other particles.

[0364] Experiment 3

[0365] The results summarized in Table 10 below outline the average residence time on the Persian clover seeds, the dimensionless variance of the particles, and the average slip velocity once the curtain reaches steady state. The slip velocity was calculated based on the particle Reynolds number extracted from CFD.

[0366] Table 10: Experiment 3 results.

[0367]

[0368] It is observed that the dimensionless variance and the mean slip velocity of the particles are improved by using a separator with two discrete flow rates. In addition, when there is a pressure drive in the downstream part of the accelerating gas line (which is only possible for upstream and downstream separators), the mean residence time is the longest, the dimensionless variance of the particles is the best, and the mean slip velocity is the highest.

[0369] The possible reason for the increase in average slip velocity is that the cross-flow gas behaves more vertically on the falling particles. This can be explained by the following geometry and the slip velocity formula, which is the magnitude of the velocity difference of the particle relative to the gas.

[0370]

[0371] x is the horizontal dimension of the chamber (eg, length), y is the vertical dimension of the chamber (eg, height), and z is the width dimension of the chamber.

[0372] When the gas flow line is perpendicular to the particle flow, that is, when the particle x-term is as close to 0 as possible and the gas x-velocity is increased, X slip maximize.

[0373] When the airflow line has a vertical downward velocity as close to zero as possible and the particles fall under the action of gravity, Y slip maximize.

[0374] The Z term is considered negligible.

[0375] Without the separator, the gas flow line becomes more parallel to the particles because the particles induce the gas to flow downward with them (reducing Y slip Separators with pressure drives help keep the overall gas flow as vertical as possible, resulting in a higher average slip velocity.

[0376] Fig.36 The graphs in are for particles cited in the study in isothermal contact with 15°C air and show the relationship between the slip velocity and the heat and mass transfer coefficients for Persian clover seeds. Fig.36 It is shown that the slip velocity has a strong influence on heat and mass transfer, and optimizing the slip velocity on the particles in the curtain will improve the contact performance in cross flow.

[0377] Fig.37 The effect of the separator on the slip velocity is shown, with the slip velocity surging to about 9 m / s at about 2.75 m in the vertical coordinate.

[0378] Figures 38 to 40 is a CFD plot showing the effect of the separator and pressure drive on the particle flow curve.

[0379] Overall, the following observations were made:

[0380] • Particle dispersity based on the dimensionless variance of the particles for the separator and separator and pressure driven device experiments provided 15-17% improvement compared to the no separator experiments.

[0381] The average slip velocity, which controls the rate of heat and mass transfer at the particle surface, is up to 26% higher. The relationship between slip velocity and heat and mass transfer coefficients generally follows a power law (for a particular particle size and gas properties), which is relatively linear in the region where typical slip velocities exist. Thus, increases similar to those of the Nusselt and Sherwood numbers result in nearly linear increases in heat and mass transfer coefficients with respect to slip velocity.

[0382] • It is more energy efficient to accelerate only a portion of the chamber cross-sectional area rather than the entire chamber cross-sectional area (assuming the compared curtains have the same trajectory).

[0383] • Use of separators and pressure drives in multi-stage processors is more compact by minimizing the chamber volume consumed by downstream vortexes.

[0384] The dimensionless variance of the particles of one curtain can be retained for the next curtain and for the entire process of n curtains.

[0385] Experiment 4

[0386] Fig.41 is a CFD diagram of a multi-curtain embodiment of the present invention without separators and pressure drive.

[0387] Fig.42 shows the sliding velocity distribution of curtain 1 without separator, Fig.43 The slip velocity curve for Curtain 2 is shown.

[0388] Table 11 provides the average sliding speed of the curtain in a two-stage processor according to the present invention. The speed is calculated based on the particle Reynolds number extracted from CFD.

[0389] Table 11: Average slip velocities from Experiment 4.

[0390]

[0391] It was observed that both curtains had lower glide speeds without separator and pressure drive than when using separator with pressure drive. This is consistent with the applicant's finding that using separator with optional pressure drive maximizes glide speed.

[0392] Two different designs (i.e., Design 1 and 2) were developed for the system with a separator and a pressure drive. Table 9 provides the parameters of the two designs.

[0393] Table 12: Dwell time distribution and average slip velocity data from Experiment 4 for double curtain simulations.

[0394]

[0395]

[0396] Table 12 shows that for the multi-stage system with separator and pressure drive, the dimensionless variance of the particles of the second curtain increases by a factor of 6, while the dimensionless variance of the total residence time of the particles increases by a factor of about 3. This means that the residence time deteriorates with the increase in the number of particle curtains and becomes difficult to control and reproduce.

[0397] With the separator and pressure drive in place, more repeatable residence time control between Curtain 1, Curtain 2, and the entire process was observed.

[0398] Design 1 shows that the dimensionless variance of the particles in Curtain 1 is 0.000326, while the dimensionless variance of the entire system of particles is 0.0007248, a loss of compactness by a factor of nearly 2.

[0399] However, in Design 2, the dimensionless variance of the particles changes from 0.000471 to 0.0006834, or a loss of compactness by a factor of about 1.45. This is an improvement over Design 1. The combination of the accelerating and main airflows with the separator and pressure drive allows for management of the total dimensionless variance of the particles of the system and confirms that in some cases the dimensionless variance of the particles of the first curtain can be transferred to the n-curtain.

[0400] Another benefit of using multiple separators and pressure drives is that it reduces the space that multiple curtains would take up. This is for a number of reasons.

[0401] First, multiple separators and pressure-driven devices mitigate the formation of downstream vortices.

[0402] Second, although the particle curtains formed by gas-particle processors with separators and pressure drives have longer trajectories, they allow the particle curtains to be formed closer together.

[0403] One problem faced by separator-less gas-particle processors is that placing the second continuous curtain too close to the first curtain (right in the middle of the vortex) will cause a sharp upward flow of gas at the upstream edge of the second curtain, followed by a very strong downward flow through the second curtain. This will increase the turbulence of the second curtain and disturb the distribution of residence time and slip velocity values.

[0404] A second particle feeder may be used to introduce particles into the chamber. The second particle feeder may be in fluid communication with the particle outlet to reintroduce the particle stream into the chamber. When a separator and a pressure drive are used, the second particle feeder may be placed closer to the first particle feeder, thereby reducing the overall length of the chamber.

[0405] The combination of increased glide speed and the ability to place the particle feeders closer together results in an increase in the volumetric heat transfer coefficient per unit chamber volume.

[0406] Design 2 has the best overall residence time distribution and average slip velocity figures, but has a larger slip velocity difference between Curtain 1 and Curtain 2 compared to Design 1. This is probably because the two curtains in Design 2 have different trajectories and there is no effectively managed accelerated gas that can penetrate the first curtain and continue onto the second curtain.

[0407] It is also observed that the impact of curtains 1 and 2 is different between designs 1 and 2 in terms of slip velocity distribution.

[0408] Fig.44 This is a CFD modeling diagram of a 2-curtain system with particle streamlines and airflow lines. Fig.45 is a graph showing the sliding speed distribution of the curtain 1 according to Design 1.

[0409] Fig.45 shows the sliding velocity distribution of curtain 1, Fig.46 The sliding velocity curve of Curtain 2 according to Design 1 is shown. The key effect of the separator on the sliding velocity distribution of the particle curtain is the surge in sliding velocity at the separator. Fig.45 and Fig.46 In the study, this surge was observed at a vertical coordinate of about 2.5 m.

[0410] Fig.47 This is a CFD modeling diagram of the 2-curtain system with particle streamlines and airflow lines according to Design 2 of Experiment 4. Fig.48 and Fig.49 Graphs showing the slip velocity distributions of Curtains 1 and 2 of Design 2 according to Experiment 4, respectively.

[0411] Design 1 has a lower accelerating gas velocity and therefore has a lower slip velocity in the accelerating gas region, producing a "flatter" distribution, while Design 2 uses a higher accelerating gas velocity and therefore has a more "parabolic" slip velocity distribution. In both cases, this observation is more pronounced in Curtain 1, while Curtain 2 has a larger slip velocity distribution due to the turbulence generated by Curtain 1.

[0412] The simulations and results from Experiment 4 demonstrate the following results:

[0413] 1. Separator and pressure drive facilitates multi-stage operation because it maximizes slip speed.

[0414] 2. The separator increases the overall tightness (measured by the dimensionless variance) of the residence time of the entire process (n curtains).

[0415] 3. The dimensionless variance of the particle values ​​extracted from the single-stage simulation is available for n number of curtains.

[0416] It will be appreciated that, if any prior art publication is referred to herein, this reference does not constitute an admission that the publication forms part of the common general knowledge in the art in Australia or any other country.

[0417] In the appended claims and foregoing description of the present invention, unless the context requires otherwise due to explicit language or necessary implication, the word "comprise" or variations such as "include" or "comprising" are used in an inclusive sense, i.e. specifying the presence of stated features but not excluding the presence or addition of further features in various embodiments of the present invention.

Claims

1. A gas-particle processor for contacting a particle stream with a gas stream, comprising: Chamber; at least one gas inlet for introducing a gas into the chamber, the gas forming an accelerating gas flow and a main gas flow in the chamber; a particle feeder in fluid communication with the particle inlet for introducing a flow of particles into the gas; and a separator for separating the accelerated gas stream from the main gas stream in at least a portion of the chamber, wherein the accelerated gas stream has a higher average velocity than the main gas stream to form a curtain of the particle stream having an upstream edge and a downstream edge; as well as A particle outlet is provided for receiving the curtain of particle flow.

2. The processor of claim 1, wherein the processor is configured such that the curtain of particle flow has a dimensionless variance of residence time of the particles reduced by at least 5% compared to a curtain of particle flow formed in a gas-particle processor without a separator.

3. A processor according to claim 1 or 2, configured to obtain an average glide velocity at least 10% higher than a gas-particle processor without a separator.

4. A processor according to any one of the preceding claims, wherein: At least one gas inlet is configured to introduce gas into the chamber in a substantially horizontal direction.

5. A processor according to any preceding claim, wherein: The particle inlet is configured to introduce a flow of particles into the gas flow in a substantially vertical direction.

6. The processor according to claim 5, wherein: The particle inlet is configured to deliver the particle flow into the accelerating gas flow.

7. A processor according to any preceding claim, configured such that less than 10% by weight of the particle stream contacts the separator.

8. A processor as claimed in any preceding claim, comprising a solids separator.

9. A processor according to any one of claims 1 to 7, comprising a perforated separator.

10. A processor according to any preceding claim, comprising at least two pairs of particle inlets and particle outlets, wherein: The first particle outlet is in fluid communication with the second particle inlet.

11. The processor of claim 10, wherein: The separator is located upstream or downstream of the particle outlet.

12. A processor according to any preceding claim, comprising pressure driven means for introducing positive pressure in the accelerating gas flow.

13. A processor according to any preceding claim, wherein: The separator is positioned to provide a clearance angle greater than 20°.

14. A method of contacting a flow of particles with a gas in a chamber, comprising: (i) introducing the gas into the chamber, at least a portion of the gas forming an accelerating gas flow and a main gas flow in the chamber, wherein the accelerating gas flow has a higher average velocity than the main gas flow; and (ii) introducing the particle stream into the gas and forming a curtain of the particle stream having an upstream edge and a downstream edge.

15. The method of claim 14, comprising controlling the gas flow into the chamber so that the curtain of particle flow has a dimensionless variance in residence time reduced by at least 5% compared to a curtain of particle flow formed in a gas-particle processor without a separator.

16. A method according to claim 14 or 15, comprising controlling one or more of the gas flow velocity, particle flow velocity, the position and size of the separator, and the chamber dimensions to obtain an average glide velocity that is at least 10% higher than a gas-particle processor without a separator.

17. A method according to any one of claims 14 to 16, comprising controlling one or more of gas flow velocity, particle flow velocity, position and size of a separator, and chamber dimensions such that less than 10% by weight of the particle flow contacts the separator.

18. A method according to any one of claims 14 to 17, comprising introducing the gas flow into the chamber in a substantially horizontal direction.

19. A method according to any one of claims 14 to 18, comprising introducing the particle stream into the gas stream in a substantially vertical direction.

20. The method of claim 19, comprising introducing the particle stream into the accelerating gas stream.

21. A method according to any one of claims 14 to 20, comprising introducing positive pressure into the accelerating airflow and increasing the velocity of the accelerating airflow.

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