WO2011144884A1 - Cyclone separator with two gas outlets and separation method - Google Patents

Cyclone separator with two gas outlets and separation method Download PDF

Info

Publication number
WO2011144884A1
WO2011144884A1 PCT/GB2010/001022 GB2010001022W WO2011144884A1 WO 2011144884 A1 WO2011144884 A1 WO 2011144884A1 GB 2010001022 W GB2010001022 W GB 2010001022W WO 2011144884 A1 WO2011144884 A1 WO 2011144884A1
Authority
WO
WIPO (PCT)
Prior art keywords
gas
flow
gas outlet
cyclone separator
separation chamber
Prior art date
Application number
PCT/GB2010/001022
Other languages
French (fr)
Inventor
Wilson Kenzo Huziwara
Celso Murilo Dos Santos
Rogério MICHELAN
Emanuel Freire Sandes
Original Assignee
Petroleo Brasileiro S.A. - Petrobras
Benson, John Everett
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Petroleo Brasileiro S.A. - Petrobras, Benson, John Everett filed Critical Petroleo Brasileiro S.A. - Petrobras
Priority to EP10721542.8A priority Critical patent/EP2571622B1/en
Priority to PCT/GB2010/001022 priority patent/WO2011144884A1/en
Priority to PT107215428T priority patent/PT2571622E/en
Priority to ES10721542.8T priority patent/ES2538831T3/en
Publication of WO2011144884A1 publication Critical patent/WO2011144884A1/en

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B04—CENTRIFUGAL APPARATUS OR MACHINES FOR CARRYING-OUT PHYSICAL OR CHEMICAL PROCESSES
    • B04C—APPARATUS USING FREE VORTEX FLOW, e.g. CYCLONES
    • B04C3/00—Apparatus in which the axial direction of the vortex flow following a screw-thread type line remains unchanged ; Devices in which one of the two discharge ducts returns centrally through the vortex chamber, a reverse-flow vortex being prevented by bulkheads in the central discharge duct
    • B04C3/06—Construction of inlets or outlets to the vortex chamber
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B04—CENTRIFUGAL APPARATUS OR MACHINES FOR CARRYING-OUT PHYSICAL OR CHEMICAL PROCESSES
    • B04C—APPARATUS USING FREE VORTEX FLOW, e.g. CYCLONES
    • B04C5/00—Apparatus in which the axial direction of the vortex is reversed
    • B04C5/12—Construction of the overflow ducting, e.g. diffusing or spiral exits
    • B04C5/13—Construction of the overflow ducting, e.g. diffusing or spiral exits formed as a vortex finder and extending into the vortex chamber; Discharge from vortex finder otherwise than at the top of the cyclone; Devices for controlling the overflow
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B04—CENTRIFUGAL APPARATUS OR MACHINES FOR CARRYING-OUT PHYSICAL OR CHEMICAL PROCESSES
    • B04C—APPARATUS USING FREE VORTEX FLOW, e.g. CYCLONES
    • B04C5/00—Apparatus in which the axial direction of the vortex is reversed
    • B04C5/14—Construction of the underflow ducting; Apex constructions; Discharge arrangements ; discharge through sidewall provided with a few slits or perforations

Definitions

  • This invention is concerned with equipment and methods for separating solid particles from gas-particle suspensions. More particularly, the invention relates to cyclone separators, in which a tangential force component is imparted to the gas- particle suspension.
  • Cyclone separators in various different constructional forms are used in a number of apparatuses for separating impurities contained in gaseous fluids, such as solid particles or dust, droplets of liquids or similar material.
  • Cyclone separators are also widely used for separating and for removing particles from the air or from process gases. They are also used as chemical reactors, heat exchangers and for drying granular materials and combustion of oil. In petroleum refineries, they are used for ensuring the continuity of the process for obtaining products, retaining a catalyst and impeding its emission into the atmosphere, preventing loss and pollution, so as to guarantee the continuity of the process.
  • the great applicability of cyclone separators is at least in part due to their low operating cost, easy maintenance and the possibility of withstanding severe temperature and pressure conditions.
  • Cyclone separators can be used in various different arrangements, in series or in parallel. In some processes, all of the gaseous fluid produced, which shall hereinafter be called gas-particle suspension, passes through the separator. In other processes, cyclone separators can be used as part of a waste gas cleaning system.
  • the particles are separated by a process of centrifugation of the gas-particle suspension.
  • This phenomenon occurs with the induction of a vortical flow inside the cyclone separator due to the significant tangential force component with which the suspension enters the cyclone chamber, which is generally of a conical-cylindrical shape.
  • the solid particles Being of greater density than the gases, the solid particles have a greater tendency to remain in the trajectory perpendicular to the vortical flow, due to centrifugal force and thus to collide with the walls of the chamber.
  • the particles lose speed and tend to separate from the flow, falling towards the bottom of the chamber, from where they are removed.
  • the gas separated is sucked out through the outlet pipe of the cyclone, after moving in several revolutions through the chamber and in a curve with an accentuated angle towards the outlet pipe in the upper part.
  • Cyclone separators of gas-particle suspensions are generally of the reverse flow type, which are the most conventional ones for this type of separation. However, unidirectional flow cyclones are also used, principally in applications where the concentration of particles in the suspension is low.
  • the gas outlet pipe In reverse flow cyclones, the gas outlet pipe, usually called the finder or vortex pipe, is fixed and located in the upper part of the cyclone. During operation, there is a need for the total reversal of the vortical flow of the gas so that it is sucked by the outlet
  • the unidirectional flow separator typically has a separation zone length shorter than that of a separator with reverse flow, this being the reason why the unidirectional flow separator is usually efficient only in gas-particle suspensions with low
  • the flow reversal zone is the region in which the greatest loss of collection efficiency of the cyclone separator occurs, due to the instability existing at the flow reversal apex, which is the moment at which the vortical flow is reversed from descending to ascending. This results in lateral displacements of the vortical flow, which causes entrainment of solids previously separated and erosion of the cyclone separator walls.
  • Patent US 4,238,210 discloses a unidirectional cyclone separator which comprises an internal duct, which forms a flow path, with a central body provided with swirl-generating vanes extending outwardly.
  • the duct is enclosed by a collecting chamber and the vanes have collecting ends and channels which open through the wall of the duct to the inside of the collecting chamber. Downstream from the swirl- generating vanes, there are outlet slots which are transverse with respect to the gas flow.
  • this equipment is efficient only for suspensions with low concentrations of particles.
  • Patent application PI0803051 -0 discloses a cyclone separator and a gas-particle separation method with two separation zones in sequence, one with reverse flow, in which a portion of the gas of the gas-particle suspension with a high concentration of solids is separated and a subsequent, unidirectional, flow separation zone in which the other portion of the gas of the suspension, with a low concentration of solids, is separated.
  • the cyclone separator is provided with two outlet pipes, one being fastened axially to the upper part and the other one being fastened axially to the lower part, generating the separation zones with reverse flow and unidirectional flow respectively.
  • the apparatus and method described below have advantages for the separation of gas-particle suspensions, using reverse flow cyclones, with respect to the devices and methods known in the prior art, for example, the apparatus and method described below prevents the problems of loss of collection efficiency and erosion in the region of reversal of the vortical flow from descending to ascending.
  • This invention relates to a cyclone separator for a gas-particle suspension.
  • the invention also relates to a separation method in which a separator as described herein is used.
  • a separator as described herein is used.
  • a separator this may be, by way of non- limitative example, a liquid particle or a solid particle.
  • a gas-particle mixture or suspension may be a gas-solid mixture or suspension, a gas-liquid mixture or suspension, or a gas-solid-liquid mixture or suspension.
  • a cyclone separator for separating particles from a mixture of gas and particles, said cyclone separator comprising:
  • an inlet configured to provide the mixture of particles and gas to the separation chamber;
  • a reverse flow gas outlet positioned to receive a portion of the gas, from which particles have been separated, from the separation chamber, the direction of this portion of the gas having been reversed in the separation chamber;
  • a unidirectional flow gas outlet positioned to receive another portion of the gas, from which particles have been separated, from the separation chamber, the direction of this portion of the gas not having been reversed in the separation chamber, wherein the reverse flow gas outlet and the unidirectional flow gas outlet are arranged such that, in operation, the mass flow rate of gas exiting via the reverse flow gas outlet is greater than the mass flow rate of gas exiting via the unidirectional flow gas outlet.
  • the mass flow rate of gas exiting via the reverse flow gas outlet is over 70% of the total mass flow rate of gas exiting from the cyclone separator.
  • the mass flow rate of gas exiting via the reverse flow gas outlet is over 95% of the total mass flow rate of gas exiting from the cyclone separator.
  • the flow area of the reverse flow gas outlet is greater than the flow area of the unidirectional flow gas outlet.
  • the diameter of the unidirectional gas flow outlet is less than 30% of the diameter of the reverse flow gas outlet.
  • the diameter of the unidirectional gas flow outlet is in the range of from 1% to 5% of the diameter of the reverse flow gas outlet.
  • the shape of a cross section of the reverse flow gas outlet perpendicular to the gas flow direction is circular;
  • the shape of a cross section of the unidirectional flow gas outlet perpendicular to the gas flow direction is circular.
  • the reverse flow gas outlet extends into the separation chamber so as to draw separated gas from inside the separation chamber;
  • the unidrectional flow gas outlet extends into the separation chamber so as to draw separated gas from inside the separation chamber.
  • the cyclone separator further comprises a solids outlet configured to allow particles, which have been separated from the gas, to exit from the separation chamber, the solids outlet optionally being aligned with the unidirectional flow gas outlet.
  • At least a part of the separation chamber has an axial centreline, and the inlet either:
  • At least a part of the separation chamber has an axial centreline, and the inlet is offset from the axial centreline.
  • the cyclone separator further comprises a second inlet configured to allow the mixture of particles and gas into the separation chamber.
  • At least a part of the separation chamber has an axial centreline and the second inlet is either:
  • the separation chamber has an inlet end
  • the inlet and reverse flow gas outlet are provided at said inlet end; and the unidirectional gas outlet is provided at an end of the separation chamber that is opposite to the inlet end.
  • the gas exits the reverse flow gas outlet in a first exit flow direction
  • the gas exits the unidirectional flow gas outlet in a second exit flow direction, the first exit flow direction being different to the second exit flow direction.
  • the first exit flow direction is substantially opposite to the second exit flow direction.
  • At least a portion of the separation chamber is radially symmetric about an axial centreline of the separation chamber.
  • the reverse flow gas outlet comprises a pipe having its centreline substantially aligned with the axial centreline of the separation chamber
  • the unidirectional flow gas outlet comprises a pipe having its centreline substantially aligned with the axial centreline of the separation chamber.
  • At least a portion of the inner wall of the separation chamber is frusto-conical.
  • a method of separating particles from a mixture of gas and particles using a cyclone separator as described herein there is provided a method of separating particles from a mixture of gas and particles using a cyclone separator as described herein.
  • a method of separating particles from a mixture of gas and particles comprising: providing the mixture to a separation chamber;
  • the mass flow rate of gas removed through the reverse flow gas outlet is greater than the mass flow rate of gas removed through the unidirectional flow gas outlet.
  • the mass flow rate of gas removed through the reverse flow gas outlet is over 70% of the total mass flow rate of gas exiting from the cyclone separator.
  • the mass flow rate of gas removed through the reverse flow gas outlet is over 95% of the total mass flow rate of gas exiting from the cyclone separator.
  • the gas that is not removed through the reverse flow gas outlet is removed through the unidirectional flow gas outlet.
  • the position at which the flow direction is reversed is inside the unidirectional flow gas outlet.
  • the portion of gas removed via the reverse flow gas outlet is removed in a substantially opposite direction to the portion of gas removed via the unidirectional flow gas outlet.
  • the step of separating the mixture comprises centrifugal separation.
  • the method further comprises removing solids separated from the mixture.
  • the concentration of particles in the mixture provided to the separation chamber is greater than 1 gm " .
  • a reverse cyclone separator of gas-solid suspension which comprises a cyclone chamber, with at least one inlet, an annular space for the collection of separated particles and two outlet pipes, one pipe being fastened axially to the upper part of the cyclone chamber and the other pipe being fastened axially to the lower part of the chamber and with an inside diameter in the range between 1% and 5% of the inside diameter of the upper pipe, both pipes having an axial extension into the chamber.
  • a method of gas-particle separation using the separator described above which comprises the stages of letting the gas-particle suspension into the chamber by means of the inlet, sucking out the gas separated, by means of the two pipes at the same time and, through an annular space, removing the separated solid particles, characterised in that a fraction of gas in proportions exceeding 95% is sucked out by the upper pipe and the complementary fraction is sucked out by the lower pipe, so as to maintain the reversal apex inside the lower pipe and stabilise the vortical flow.
  • This method may stabilise the ascending vortical flow.
  • the descending flow may be stabilised by the wall of the cyclone chamber.
  • the method may also comprise imparting a tangential force component to the gas-particle suspension so as to separate the suspension.
  • the method may let the gas-solid suspension into the cyclone chamber by means of the (first) inlet and at least one additional inlet positioned symmetrically with the (first) inlet.
  • Fig. 1 gives a perspective cutaway representation of the cyclone separator for a gas-particle suspension in a configuration with two inlets according to an embodiment of the invention, as well as a schematic representation of the separation method using the cyclone separator according to an embodiment of the invention.
  • Fig. 2 gives a perspective representation of a cyclone separator for a gas-particle suspension in a configuration with two inlets according to an embodiment of the invention.
  • This invention discloses a cyclone separator for a gas-particle suspension. Also disclosed is a separation method in which the separator is capable of maintaining the stability of the ascending vortical flow during the separation process.
  • the cyclone separator comprises a cyclone chamber (1) (which may be referred to as a separation chamber (1)), with at least one inlet (1 la), an annular space (13) for the collection of separated particles and two outlet pipes, one (upper) pipe (2) being fastened axially to the upper part of the cyclone chamber (1) and the other (lower) pipe (3) being fastened axially to the lower part of the chamber (1), both pipes having an axial extension into the chamber (1).
  • the lower pipe (3) (which may also be referred to as an unidirectional flow gas outlet (3)) has an inside diameter that is smaller, for example significantly and/or considerably smaller, than the inside diameter of the upper pipe (2) (which may also be referred to as an reverse flow gas outlet (2)).
  • the inside diameter of the lower pipe (3) may be in the range of from 0.1% to less than 50% of the inside diameter of the upper pipe (3).
  • the inside diameter of the lower pipe (3) may be in the range of from 1% to 40% of the inside diameter of the upper pipe (2).
  • the inside diameter of the lower pipe (3) may be in the range of from 2% to 35% of the inside diameter of the upper pipe (2).
  • the inside diameter of the lower pipe (3) may be in the range of from 5% to 30% of the inside diameter of the upper pipe (2).
  • the inside diameter of the lower pipe (3) may be in the range of from 10% to 25% of the inside diameter of the upper pipe (2), for example around 22.4%.
  • the inside diameter of the lower pipe (3) may be in the range of from 15 to 20% of the inside diameter of the upper pipe (2).
  • the upper pipe (2) and the lower pipe (3) may take any suitable shape, for example in cross section.
  • the cross sectional shape of the upper pipe (2) is circular and the cross sectional shape of the lower pipe (3) is circular.
  • any cross sectional shape may be used for the upper pipe (2) and the lower pipe (3).
  • the cross sectional shape could be a polygon, such as a regular polygon, for example a triangle, a square, a pentagon, or a hexagon.
  • the cross sectional shape may be irregular.
  • the cross sectional shape of the upper pipe (2) and the lower pipe (3) may be the same as each other or different to each other.
  • the cross sectional shape and/or dimension of one or both of the upper pipe (2) and the lower pipe (3) may be the same along its length, or may change along its length.
  • pipe is used herein with regard to the upper pipe (2) and the lower pipe (3), it will be appreciated that any suitable outlets (for example gas outlets) configured to allow gas to exit the separation chamber (1) could be used at the location of the upper pipe (2) and the lower pipe (3).
  • the flow area of the lower pipe (3) may be less than 50% of the flow area of the upper pipe (2).
  • the flow area of the lower pipe (3) may be in the range of from 0.1% to 30% of the flow area of the upper pipe (2). In an embodiment, the flow area of the lower pipe (3) may be in the range of from 0.2% to 20% of the flow area of the upper pipe (2). In an embodiment, the flow area of the lower pipe (3) may be in the range of from 0.5% to 10% of the flow area of the upper pipe (2). In an embodiment, the flow area of the lower pipe (3) may be in the range of from 1% to 5% of the flow area of the upper pipe (2). In an embodiment, the flow area of the lower pipe (3) may be around 2.5% of the flow area of the upper pipe (2).
  • the mass flow rate of gas extracted through the upper pipe (2) may be greater than the mass flow rate of gas extracted through the lower pipe (3).
  • This may be achieved by any suitable means for example, it may be achieved by having the cross sectional area (which may be referred to as the flow area) of the upper pipe (2) (or reverse flow gas outlet) greater than the cross sectional area of the lower pipe (3) (or unidirectional flow gas outlet).
  • the cross sectional area of the upper pipe (2) may be significantly and/or considerably greater than the cross sectional area of the lower pipe (3). In this case, the vast majority of the gas (from which the particles have been separated) is extracted through the upper pipe (2), such that the cyclone separator acts as, or acts substantially as, a reverse flow cyclone separator.
  • the diameter of the lower pipe (3) may be less than 50% of the diameter of the upper pipe (2). In an embodiment, the diameter of the lower pipe (3) may be in the range of from 0.1% to 30% of the diameter of the upper pipe (2). In an embodiment, the diameter of the lower pipe (3) may be in the range of from 0.2% to 20% of the diameter of the upper pipe (2). In an embodiment, the diameter of the lower pipe (3) may be in the range of from 0.5% to 10% of the diameter of the upper pipe (2). In an embodiment, the diameter of the lower pipe (3) may be in the range of from 1% to 5% of the diameter of the upper pipe (2). In an embodiment, the diameter of the lower pipe (3) may be around 2.5% of the diameter of the upper pipe (2).
  • any suitable location along the respective outlet may be used.
  • the cross sectional area and/or diameter and/or shape at the entrance to the respective outlet may be used.
  • the cross-sectioned area and/or diameter and/or shape at the point along the respective outlet where the suction pressure acts on the exit may be used.
  • the method of gas-particle separation using the separator described above comprises the stages of letting the gas-particle suspension into the chamber (1) by means of the inlet (11a), and imparting a tangential force component to the gas-particle suspension.
  • the tangential force component of the gas-particle suspension may be provided by swirling, or rotating, the gas-particle suspension inside the chamber (1) by any suitable means.
  • the gas-particle suspension may be separated, or substantially separated, for example into a gaseous (or predominantly gaseous) phase or portion, and a particle (or predominantly particle) phase or portion.
  • the particle phase may be solid, liquid, or a mixture of solid and liquid.
  • the method may include removing (for example sucking out) the gas separated from the gas- particle suspension by means of the upper pipe (2) and the lower pipe (3).
  • the gas may be sucked out, or removed, from the chamber (1), from both the upper pipe (2) and the lower pipe (3) at the same time.
  • the separated particles (for example the solid phase, or portion) may be removed through a particles (or solids) outlet.
  • a solids outlet is shown as an annular solids outlet (13).
  • a higher fraction of gas may be removed, or sucked out, by the upper pipe (2). This may, for example, maintain the position of the reversal apex inside the lower pipe (3) and thereby stabilise the vortical flow.
  • more than 50% of the gas may be removed, or sucked out, by the upper pipe (2).
  • the remainder may be sucked out by the lower pipe (3).
  • the proportion of gas removed, or sucked out, by the upper pipe (2) is in the range of from 60% to 99%, the remainder being removed, or sucked out, by the lower pipe (3).
  • the proportion of gas removed, or sucked out, by the upper pipe (2) is in the range of from 70% to 98%, the remainder being removed, or sucked out, by the lower pipe (3).
  • the proportion of gas removed, or sucked out, by the upper pipe (2) is in the range of from 80% to 97%, the remainder being removed, or sucked out, by the lower pipe (3).
  • the proportion of gas removed, or sucked out, by the upper pipe (2) is in the range of from 90% to 96%», the remainder being removed, or sucked out, by the lower pipe (3).
  • the proportion of gas that is removed, or sucked out, by the upper pipe (2) exceeds 95%, with the remainder being removed, or sucked out by the lower pipe (3).
  • the relative portions removed from the two gas outlets described above may equate to the relative mass flow rates in the two outlets.
  • the upper pipe (2) is provided at the same end of the separation chamber (1) as the inlet (1 la) of the two-phase mixture (which may also be referred to as a gas-particle suspension or mixture).
  • the separation chamber (1) may have a longitudinal axis, and the upper pipe (2) may be provided at, or towards, the same axial end of the separation chamber (1) as the inlet (1 la).
  • the lower pipe (3) may be provided at an end of the separation chamber (1) that is opposite (for example at the opposite end on a longitudinal axis of the separation chamber ( 1 )) to the inlet ( 11 a) .
  • the upper pipe (2) in operation, receives a portion of the gas whose direction has been reversed inside the separation chamber (1).
  • the upper pipe (2) may be referred to as a reverse flow gas outlet (2), as stated above.
  • the upper pipe (2) may be referred to as an upper outlet (2) or a first gas outlet (2).
  • the lower pipe (3) in operation, is configured to receive a portion of the gas from the separation chamber (1) whose direction has not been reversed in the separation chamber (1).
  • the lower pipe (3) may be configured such that the gas-particle suspension flows from the inlet (1 la) to the lower pipe (3) without having its direction (for example axial direction) reversed, with at least some of the particles being separated from the gas-particle suspension as it flows from the inlet (1 la) to the lower pipe (3).
  • the lower pipe (3) may be referred to as a unidirectional flow gas outlet (3), as stated above.
  • the lower pipe (3) may be referred to as a lower outlet (3) or as a second gas outlet (3).
  • the reversal of the vortical flow from descending towards the lower pipe (3) to ascending towards the upper pipe (2) can be controlled so as to be far removed from the internal walls of the separation chamber (1).
  • the apex (or position) of the reversal of the vortical flow from descending towards the lower pipe (3) to ascending towards the upper pipe (2) may be inside the lower pipe (3), or near to the entrance of the lower pipe (3). This may be achieved, for example, by setting the relative diameters and/or areas of the upper pipe (2) and the lower pipe (3) to be in the proportions described herein.
  • the position or apex of the reversal of the vortical flow may be controlled in embodiments of the present invention by controlling the relative fraction of gas removed by the upper pipe (2) and the lower pipe (3) (for example the relative mass flow rates through the the upper pipe (2) and the lower pipe (3)) to be in the proportions described herein.
  • the present invention can reduce entrainment, by the gas, of solid particles that have already been separated from the gas-particle suspension.
  • An additional, or alternative, advantage is that by controlling the apex (or position) of the reversal of the vortical flow to be far away from the internal walls of the separation chamber (1), erosion of the separation chamber internal walls can be reduced or prevented.
  • This gas-particle separation apparatus and method of the present invention is suitable for separating suspensions with a wide range of concentrations of solid.
  • the method may be particularly suitable for separating suspensions with concentrations of solid exceeding 1 g/m .
  • the method and apparatus of the present invention is capable of being used individually or as a stage of equipment which has multiple cyclone separators connected together, for example in series.
  • the cyclone separator of the present invention may be provided with one inlet (Ha) through which the gas-particle suspension enters into the separation chamber (1).
  • Other embodiments may have more than one inlet through which the gas-particle suspension enters the separation chamber (1).
  • Fig. 1 shows an example of the present invention which has one inlet (1 la) and an additional inlet (l ib).
  • Fig.2 also shows such an embodiment.
  • the additional inlet (1 lb) is positioned with its axis diametrically opposite to the axis of the first inlet (11a).
  • the additional inlet (1 lb) is positioned to be diametrically opposite to, or symmetric with, the first inlet (11a).
  • the apparatus and method of the present invention have a number of advantages over the prior art.
  • the apparatus and method of the present invention have the following advantages at least: i. substantial reduction of the erosion in the lower region of the separator, the erosion being caused by the instability of the vortical flow in the region of the apex during reversal of the flow from descending to ascending in conventional cyclone separators,

Landscapes

  • Cyclones (AREA)

Abstract

The separator comprises a separation chamber with at least one inlet in its upper part, a solids outlet in its lower part, an upper gas outlet, and a lower gas outlet. The proportion of gas removed through the upper gas outlet is significantly greater than the proportion of gas removed through the lower gas outlet. This is achieved by having the area of the upper gas outlet significantly larger than the area of the lower gas outlet.

Description

CYCLONE SEPARATOR WITH TWO GAS OUTLETS AND SEPARATION METHOD
FIELD OF THE INVENTION
This invention is concerned with equipment and methods for separating solid particles from gas-particle suspensions. More particularly, the invention relates to cyclone separators, in which a tangential force component is imparted to the gas- particle suspension. BACKGROUND OF THE INVENTION
Cyclone separators in various different constructional forms are used in a number of apparatuses for separating impurities contained in gaseous fluids, such as solid particles or dust, droplets of liquids or similar material.
Cyclone separators are also widely used for separating and for removing particles from the air or from process gases. They are also used as chemical reactors, heat exchangers and for drying granular materials and combustion of oil. In petroleum refineries, they are used for ensuring the continuity of the process for obtaining products, retaining a catalyst and impeding its emission into the atmosphere, preventing loss and pollution, so as to guarantee the continuity of the process. The great applicability of cyclone separators is at least in part due to their low operating cost, easy maintenance and the possibility of withstanding severe temperature and pressure conditions.
Cyclone separators can be used in various different arrangements, in series or in parallel. In some processes, all of the gaseous fluid produced, which shall hereinafter be called gas-particle suspension, passes through the separator. In other processes, cyclone separators can be used as part of a waste gas cleaning system.
The particles are separated by a process of centrifugation of the gas-particle suspension. This phenomenon occurs with the induction of a vortical flow inside the cyclone separator due to the significant tangential force component with which the suspension enters the cyclone chamber, which is generally of a conical-cylindrical shape. Being of greater density than the gases, the solid particles have a greater tendency to remain in the trajectory perpendicular to the vortical flow, due to centrifugal force and thus to collide with the walls of the chamber. With the collisions, the particles lose speed and tend to separate from the flow, falling towards the bottom of the chamber, from where they are removed. The gas separated is sucked out through the outlet pipe of the cyclone, after moving in several revolutions through the chamber and in a curve with an accentuated angle towards the outlet pipe in the upper part.
Cyclone separators of gas-particle suspensions are generally of the reverse flow type, which are the most conventional ones for this type of separation. However, unidirectional flow cyclones are also used, principally in applications where the concentration of particles in the suspension is low.
In reverse flow cyclones, the gas outlet pipe, usually called the finder or vortex pipe, is fixed and located in the upper part of the cyclone. During operation, there is a need for the total reversal of the vortical flow of the gas so that it is sucked by the outlet
Pipe- In unidirectional flow cyclones (also known as "uniflow" cyclones), the gas outlet pipe is located in the lower part of the cyclone separator, there consequently not being a need for reversal of the vortical flow.
The unidirectional flow separator typically has a separation zone length shorter than that of a separator with reverse flow, this being the reason why the unidirectional flow separator is usually efficient only in gas-particle suspensions with low
concentrations of solids.
Although the separation zone of the reverse flow separator is larger, the flow reversal zone is the region in which the greatest loss of collection efficiency of the cyclone separator occurs, due to the instability existing at the flow reversal apex, which is the moment at which the vortical flow is reversed from descending to ascending. This results in lateral displacements of the vortical flow, which causes entrainment of solids previously separated and erosion of the cyclone separator walls.
Patent US 4,238,210 discloses a unidirectional cyclone separator which comprises an internal duct, which forms a flow path, with a central body provided with swirl-generating vanes extending outwardly. The duct is enclosed by a collecting chamber and the vanes have collecting ends and channels which open through the wall of the duct to the inside of the collecting chamber. Downstream from the swirl- generating vanes, there are outlet slots which are transverse with respect to the gas flow.
As with the other unidirectional cyclone separators, this equipment is efficient only for suspensions with low concentrations of particles.
Patent application PI0803051 -0, owned by the applicant, discloses a cyclone separator and a gas-particle separation method with two separation zones in sequence, one with reverse flow, in which a portion of the gas of the gas-particle suspension with a high concentration of solids is separated and a subsequent, unidirectional, flow separation zone in which the other portion of the gas of the suspension, with a low concentration of solids, is separated.
The cyclone separator is provided with two outlet pipes, one being fastened axially to the upper part and the other one being fastened axially to the lower part, generating the separation zones with reverse flow and unidirectional flow respectively.
The apparatus and method described below have advantages for the separation of gas-particle suspensions, using reverse flow cyclones, with respect to the devices and methods known in the prior art, for example, the apparatus and method described below prevents the problems of loss of collection efficiency and erosion in the region of reversal of the vortical flow from descending to ascending. SUMMARY OF THE INVENTION
This invention relates to a cyclone separator for a gas-particle suspension. The invention also relates to a separation method in which a separator as described herein is used. Where any reference is made herein to a "particle", this may be, by way of non- limitative example, a liquid particle or a solid particle. Thus, a gas-particle mixture or suspension may be a gas-solid mixture or suspension, a gas-liquid mixture or suspension, or a gas-solid-liquid mixture or suspension.
According to an aspect of the invention, there is provided a cyclone separator for separating particles from a mixture of gas and particles, said cyclone separator comprising:
a separation chamber in which the particles are separated from the gas;
an inlet configured to provide the mixture of particles and gas to the separation chamber; a reverse flow gas outlet positioned to receive a portion of the gas, from which particles have been separated, from the separation chamber, the direction of this portion of the gas having been reversed in the separation chamber; and
a unidirectional flow gas outlet positioned to receive another portion of the gas, from which particles have been separated, from the separation chamber, the direction of this portion of the gas not having been reversed in the separation chamber, wherein the reverse flow gas outlet and the unidirectional flow gas outlet are arranged such that, in operation, the mass flow rate of gas exiting via the reverse flow gas outlet is greater than the mass flow rate of gas exiting via the unidirectional flow gas outlet.
According to an embodiment, in operation, the mass flow rate of gas exiting via the reverse flow gas outlet is over 70% of the total mass flow rate of gas exiting from the cyclone separator.
According to an embodiment, in operation, the mass flow rate of gas exiting via the reverse flow gas outlet is over 95% of the total mass flow rate of gas exiting from the cyclone separator.
According to an embodiment, the flow area of the reverse flow gas outlet is greater than the flow area of the unidirectional flow gas outlet.
According to an embodiment, the diameter of the unidirectional gas flow outlet is less than 30% of the diameter of the reverse flow gas outlet.
According to an embodiment, the diameter of the unidirectional gas flow outlet is in the range of from 1% to 5% of the diameter of the reverse flow gas outlet.
According to an embodiment, the shape of a cross section of the reverse flow gas outlet perpendicular to the gas flow direction is circular; and/or
the shape of a cross section of the unidirectional flow gas outlet perpendicular to the gas flow direction is circular.
According to an embodiment, the reverse flow gas outlet extends into the separation chamber so as to draw separated gas from inside the separation chamber; and/or
the unidrectional flow gas outlet extends into the separation chamber so as to draw separated gas from inside the separation chamber.
According to an embodiment, the cyclone separator further comprises a solids outlet configured to allow particles, which have been separated from the gas, to exit from the separation chamber, the solids outlet optionally being aligned with the unidirectional flow gas outlet.
According to an embodiment, at least a part of the separation chamber has an axial centreline, and the inlet either:
is substantially parallel to the axial centreline;
is substantially perpendicular to the axial centreline; or
forms a scroll around the axis centreline.
According to an embodiment, at least a part of the separation chamber has an axial centreline, and the inlet is offset from the axial centreline.
According to an embodiment, the cyclone separator further comprises a second inlet configured to allow the mixture of particles and gas into the separation chamber.
According to an embodiment, at least a part of the separation chamber has an axial centreline and the second inlet is either:
substantially parallel to the axial centreline;
substantially perpendicular to the axial centreline; or
forms a scroll around the axis centreline.
According to an embodiment: the separation chamber has an inlet end;
the inlet and reverse flow gas outlet are provided at said inlet end; and the unidirectional gas outlet is provided at an end of the separation chamber that is opposite to the inlet end.
According to an embodiment: the gas exits the reverse flow gas outlet in a first exit flow direction; and
the gas exits the unidirectional flow gas outlet in a second exit flow direction, the first exit flow direction being different to the second exit flow direction.
According to an embodiment, the first exit flow direction is substantially opposite to the second exit flow direction.
According to an embodiment, at least a portion of the separation chamber is radially symmetric about an axial centreline of the separation chamber.
According to an embodiment: the reverse flow gas outlet comprises a pipe having its centreline substantially aligned with the axial centreline of the separation chamber, and/or the unidirectional flow gas outlet comprises a pipe having its centreline substantially aligned with the axial centreline of the separation chamber.
According to an embodiment, at least a portion of the inner wall of the separation chamber is frusto-conical.
According to an aspect of the invention, there is provided a method of separating particles from a mixture of gas and particles using a cyclone separator as described herein.
According to an aspect of the invention, there is provided a method of separating particles from a mixture of gas and particles, said method comprising: providing the mixture to a separation chamber;
reversing the flow direction of a portion of the gas;
allowing another portion of the gas to continue without reversing its flow direction;
removing the portion of gas whose direction has not been reversed via a unidirectional flow gas outlet; and
removing the portion of gas whose direction has been reversed via a reverse flow gas outlet, wherein
the mass flow rate of gas removed through the reverse flow gas outlet is greater than the mass flow rate of gas removed through the unidirectional flow gas outlet.
According to an embodiment, the mass flow rate of gas removed through the reverse flow gas outlet is over 70% of the total mass flow rate of gas exiting from the cyclone separator.
According to an embodiment, the mass flow rate of gas removed through the reverse flow gas outlet is over 95% of the total mass flow rate of gas exiting from the cyclone separator.
According to an embodiment, the gas that is not removed through the reverse flow gas outlet is removed through the unidirectional flow gas outlet.
According to an embodiment, the position at which the flow direction is reversed is inside the unidirectional flow gas outlet.
According to an embodiment, the portion of gas removed via the reverse flow gas outlet is removed in a substantially opposite direction to the portion of gas removed via the unidirectional flow gas outlet. According to an embodiment, the step of separating the mixture comprises centrifugal separation.
According to an embodiment, the method further comprises removing solids separated from the mixture.
According to an embodiment, the concentration of particles in the mixture provided to the separation chamber is greater than 1 gm" .
According to an embodiment, there is provided a reverse cyclone separator of gas-solid suspension, which comprises a cyclone chamber, with at least one inlet, an annular space for the collection of separated particles and two outlet pipes, one pipe being fastened axially to the upper part of the cyclone chamber and the other pipe being fastened axially to the lower part of the chamber and with an inside diameter in the range between 1% and 5% of the inside diameter of the upper pipe, both pipes having an axial extension into the chamber.
According to an embodiment, there is provided a method of gas-particle separation using the separator described above which comprises the stages of letting the gas-particle suspension into the chamber by means of the inlet, sucking out the gas separated, by means of the two pipes at the same time and, through an annular space, removing the separated solid particles, characterised in that a fraction of gas in proportions exceeding 95% is sucked out by the upper pipe and the complementary fraction is sucked out by the lower pipe, so as to maintain the reversal apex inside the lower pipe and stabilise the vortical flow. This method may stabilise the ascending vortical flow. The descending flow may be stabilised by the wall of the cyclone chamber. The method may also comprise imparting a tangential force component to the gas-particle suspension so as to separate the suspension.
The method may let the gas-solid suspension into the cyclone chamber by means of the (first) inlet and at least one additional inlet positioned symmetrically with the (first) inlet.
BRIEF DESCRIPTION OF THE DRAWINGS
The features of the cyclone separator of a gas-particle suspension and a separation method, which are the object of this invention, will be perceived better from the detailed description, provided by way of example only, associated with the illustration referenced below, which is an integral part of this specification.
Fig. 1 gives a perspective cutaway representation of the cyclone separator for a gas-particle suspension in a configuration with two inlets according to an embodiment of the invention, as well as a schematic representation of the separation method using the cyclone separator according to an embodiment of the invention.
Fig. 2 gives a perspective representation of a cyclone separator for a gas-particle suspension in a configuration with two inlets according to an embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
This invention discloses a cyclone separator for a gas-particle suspension. Also disclosed is a separation method in which the separator is capable of maintaining the stability of the ascending vortical flow during the separation process.
According to an embodiment, the cyclone separator comprises a cyclone chamber (1) (which may be referred to as a separation chamber (1)), with at least one inlet (1 la), an annular space (13) for the collection of separated particles and two outlet pipes, one (upper) pipe (2) being fastened axially to the upper part of the cyclone chamber (1) and the other (lower) pipe (3) being fastened axially to the lower part of the chamber (1), both pipes having an axial extension into the chamber (1).
In this configuration, in a manner different from the prior art, the lower pipe (3) (which may also be referred to as an unidirectional flow gas outlet (3)) has an inside diameter that is smaller, for example significantly and/or considerably smaller, than the inside diameter of the upper pipe (2) (which may also be referred to as an reverse flow gas outlet (2)). For example, the inside diameter of the lower pipe (3) may be in the range of from 0.1% to less than 50% of the inside diameter of the upper pipe (3).
Preferably, the inside diameter of the lower pipe (3) may be in the range of from 1% to 40% of the inside diameter of the upper pipe (2). Preferably, the inside diameter of the lower pipe (3) may be in the range of from 2% to 35% of the inside diameter of the upper pipe (2). Preferably, the inside diameter of the lower pipe (3) may be in the range of from 5% to 30% of the inside diameter of the upper pipe (2). Preferably, the inside diameter of the lower pipe (3) may be in the range of from 10% to 25% of the inside diameter of the upper pipe (2), for example around 22.4%. In an embodiment, the inside diameter of the lower pipe (3) may be in the range of from 15 to 20% of the inside diameter of the upper pipe (2).
The upper pipe (2) and the lower pipe (3), may take any suitable shape, for example in cross section. In an embodiment, the cross sectional shape of the upper pipe (2) is circular and the cross sectional shape of the lower pipe (3) is circular.
However, any cross sectional shape may be used for the upper pipe (2) and the lower pipe (3). For example, the cross sectional shape could be a polygon, such as a regular polygon, for example a triangle, a square, a pentagon, or a hexagon. Alternatively, the cross sectional shape may be irregular. The cross sectional shape of the upper pipe (2) and the lower pipe (3) may be the same as each other or different to each other. The cross sectional shape and/or dimension of one or both of the upper pipe (2) and the lower pipe (3) may be the same along its length, or may change along its length.
Indeed, although the term "pipe" is used herein with regard to the upper pipe (2) and the lower pipe (3), it will be appreciated that any suitable outlets (for example gas outlets) configured to allow gas to exit the separation chamber (1) could be used at the location of the upper pipe (2) and the lower pipe (3).
It will therefore be understood that where the term "diameter" is used herein, this should not be limiting on the shape of the upper pipe (2) or lower pipe (3). For example, where ranges of the relative diameter of the upper pipe (2) and lower pipe (3) are given, such ranges also disclose ranges of relative areas of the upper pipe (2) and the lower pipe (3) with any cross sectional shape that correspond to the area ratios of circular upper (2) and lower (3) pipes with the given diameter ratios. In other words, the relative areas of the upper and lower pipes may be in ranges corresponding to the diameter ranges given herein, regardless of the cross sectional shape of the upper pipe (2) and lower pipe (3).
For example, regardless of the shape of the pipes, the flow area of the lower pipe (3) may be less than 50% of the flow area of the upper pipe (2). In an
embodiment, the flow area of the lower pipe (3) may be in the range of from 0.1% to 30% of the flow area of the upper pipe (2). In an embodiment, the flow area of the lower pipe (3) may be in the range of from 0.2% to 20% of the flow area of the upper pipe (2). In an embodiment, the flow area of the lower pipe (3) may be in the range of from 0.5% to 10% of the flow area of the upper pipe (2). In an embodiment, the flow area of the lower pipe (3) may be in the range of from 1% to 5% of the flow area of the upper pipe (2). In an embodiment, the flow area of the lower pipe (3) may be around 2.5% of the flow area of the upper pipe (2).
Regardless of the cross sectional shape of the upper pipe (2) and the lower pipe
(3), the mass flow rate of gas extracted through the upper pipe (2) may be greater than the mass flow rate of gas extracted through the lower pipe (3). This may be achieved by any suitable means for example, it may be achieved by having the cross sectional area (which may be referred to as the flow area) of the upper pipe (2) (or reverse flow gas outlet) greater than the cross sectional area of the lower pipe (3) (or unidirectional flow gas outlet). In an embodiment, the cross sectional area of the upper pipe (2) may be significantly and/or considerably greater than the cross sectional area of the lower pipe (3). In this case, the vast majority of the gas (from which the particles have been separated) is extracted through the upper pipe (2), such that the cyclone separator acts as, or acts substantially as, a reverse flow cyclone separator.
The diameter of the lower pipe (3) may be less than 50% of the diameter of the upper pipe (2). In an embodiment, the diameter of the lower pipe (3) may be in the range of from 0.1% to 30% of the diameter of the upper pipe (2). In an embodiment, the diameter of the lower pipe (3) may be in the range of from 0.2% to 20% of the diameter of the upper pipe (2). In an embodiment, the diameter of the lower pipe (3) may be in the range of from 0.5% to 10% of the diameter of the upper pipe (2). In an embodiment, the diameter of the lower pipe (3) may be in the range of from 1% to 5% of the diameter of the upper pipe (2). In an embodiment, the diameter of the lower pipe (3) may be around 2.5% of the diameter of the upper pipe (2).
For the purposes of references the cross sectional areas, diameters and shapes of the examples used herein, any suitable location along the respective outlet may be used. For example, the cross sectional area and/or diameter and/or shape at the entrance to the respective outlet may be used. The cross-sectioned area and/or diameter and/or shape at the point along the respective outlet where the suction pressure acts on the exit may be used.
The method of gas-particle separation using the separator described above comprises the stages of letting the gas-particle suspension into the chamber (1) by means of the inlet (11a), and imparting a tangential force component to the gas-particle suspension. The tangential force component of the gas-particle suspension may be provided by swirling, or rotating, the gas-particle suspension inside the chamber (1) by any suitable means. In this way, the gas-particle suspension may be separated, or substantially separated, for example into a gaseous (or predominantly gaseous) phase or portion, and a particle (or predominantly particle) phase or portion. As mentioned above, the particle phase may be solid, liquid, or a mixture of solid and liquid.
In an embodiment of gas-particle separation using the cyclone separator according to the present invention, the method (which is also a part of the invention) may include removing (for example sucking out) the gas separated from the gas- particle suspension by means of the upper pipe (2) and the lower pipe (3). The gas may be sucked out, or removed, from the chamber (1), from both the upper pipe (2) and the lower pipe (3) at the same time. The separated particles (for example the solid phase, or portion) may be removed through a particles (or solids) outlet. In Fig. 1, such a solids outlet is shown as an annular solids outlet (13).
According to the apparatus and method of the present invention, a higher fraction of gas may be removed, or sucked out, by the upper pipe (2). This may, for example, maintain the position of the reversal apex inside the lower pipe (3) and thereby stabilise the vortical flow. In an embodiment of the invention, more than 50% of the gas may be removed, or sucked out, by the upper pipe (2). The remainder may be sucked out by the lower pipe (3). Preferably, the proportion of gas removed, or sucked out, by the upper pipe (2) is in the range of from 60% to 99%, the remainder being removed, or sucked out, by the lower pipe (3). Preferably, the proportion of gas removed, or sucked out, by the upper pipe (2) is in the range of from 70% to 98%, the remainder being removed, or sucked out, by the lower pipe (3). Preferably, the proportion of gas removed, or sucked out, by the upper pipe (2) is in the range of from 80% to 97%, the remainder being removed, or sucked out, by the lower pipe (3).
Preferably, the proportion of gas removed, or sucked out, by the upper pipe (2) is in the range of from 90% to 96%», the remainder being removed, or sucked out, by the lower pipe (3). In an embodiment, the proportion of gas that is removed, or sucked out, by the upper pipe (2) exceeds 95%, with the remainder being removed, or sucked out by the lower pipe (3). The relative portions removed from the two gas outlets described above may equate to the relative mass flow rates in the two outlets.
In an embodiment of the invention, such as that shown in Fig. 1 , the upper pipe (2) is provided at the same end of the separation chamber (1) as the inlet (1 la) of the two-phase mixture (which may also be referred to as a gas-particle suspension or mixture). The separation chamber (1) may have a longitudinal axis, and the upper pipe (2) may be provided at, or towards, the same axial end of the separation chamber (1) as the inlet (1 la). The lower pipe (3) may be provided at an end of the separation chamber (1) that is opposite (for example at the opposite end on a longitudinal axis of the separation chamber ( 1 )) to the inlet ( 11 a) .
According to an embodiment of the invention, the upper pipe (2), in operation, receives a portion of the gas whose direction has been reversed inside the separation chamber (1). As such, the upper pipe (2) may be referred to as a reverse flow gas outlet (2), as stated above. Still alternatively, the upper pipe (2) may be referred to as an upper outlet (2) or a first gas outlet (2).
The lower pipe (3), in operation, is configured to receive a portion of the gas from the separation chamber (1) whose direction has not been reversed in the separation chamber (1). In other words, the lower pipe (3) may be configured such that the gas-particle suspension flows from the inlet (1 la) to the lower pipe (3) without having its direction (for example axial direction) reversed, with at least some of the particles being separated from the gas-particle suspension as it flows from the inlet (1 la) to the lower pipe (3). As such, the lower pipe (3) may be referred to as a unidirectional flow gas outlet (3), as stated above. Alternatively, the lower pipe (3) may be referred to as a lower outlet (3) or as a second gas outlet (3).
According to an arrangement of cyclone separator of the present invention, the reversal of the vortical flow from descending towards the lower pipe (3) to ascending towards the upper pipe (2) can be controlled so as to be far removed from the internal walls of the separation chamber (1). For example, the apex (or position) of the reversal of the vortical flow from descending towards the lower pipe (3) to ascending towards the upper pipe (2) may be inside the lower pipe (3), or near to the entrance of the lower pipe (3). This may be achieved, for example, by setting the relative diameters and/or areas of the upper pipe (2) and the lower pipe (3) to be in the proportions described herein. Alternatively or additionally, the position or apex of the reversal of the vortical flow may be controlled in embodiments of the present invention by controlling the relative fraction of gas removed by the upper pipe (2) and the lower pipe (3) (for example the relative mass flow rates through the the upper pipe (2) and the lower pipe (3)) to be in the proportions described herein.
By controlling the apex (or position) of the reversal of the vortical flow from descending to ascending to be far away from the internal walls of the separation chamber (1), the present invention can reduce entrainment, by the gas, of solid particles that have already been separated from the gas-particle suspension. An additional, or alternative, advantage is that by controlling the apex (or position) of the reversal of the vortical flow to be far away from the internal walls of the separation chamber (1), erosion of the separation chamber internal walls can be reduced or prevented.
This gas-particle separation apparatus and method of the present invention is suitable for separating suspensions with a wide range of concentrations of solid. For example, the method may be particularly suitable for separating suspensions with concentrations of solid exceeding 1 g/m . The method and apparatus of the present invention is capable of being used individually or as a stage of equipment which has multiple cyclone separators connected together, for example in series.
The cyclone separator of the present invention may be provided with one inlet (Ha) through which the gas-particle suspension enters into the separation chamber (1). Other embodiments may have more than one inlet through which the gas-particle suspension enters the separation chamber (1). For example, there may be 2, 3, 4 or more than 4 inlets into the separation chamber (1). Fig. 1 shows an example of the present invention which has one inlet (1 la) and an additional inlet (l ib). Fig.2 also shows such an embodiment. In the example shown in Fig. 2 (and indeed Fig. 1), the additional inlet (1 lb) is positioned with its axis diametrically opposite to the axis of the first inlet (11a). In other words, the additional inlet (1 lb) is positioned to be diametrically opposite to, or symmetric with, the first inlet (11a).
The apparatus and method of the present invention have a number of advantages over the prior art. For example the apparatus and method of the present invention have the following advantages at least: i. substantial reduction of the erosion in the lower region of the separator, the erosion being caused by the instability of the vortical flow in the region of the apex during reversal of the flow from descending to ascending in conventional cyclone separators,
ii. maintenance of the separation efficiency throughout the length of the path taken by the gas-particle suspension, and
iii. reduction of the entrainment, by the gas, of solid material already
separated.
The description which has so far been given of this separation method must be considered only as one possible embodiment and any particular features must be understood as being described only to assist understanding. This being the case, the description herein should not be interpreted as limiting the scope of the invention, which is defined in the claims.

Claims

1. A cyclone separator for separating particles from a mixture of gas and particles, said cyclone separator comprising:
a separation chamber in which the particles are separated from the gas;
an inlet configured to provide the mixture of particles and gas to the separation chamber;
a reverse flow gas outlet positioned to receive a portion of the gas, from which particles have been separated, from the separation chamber, the direction of this portion of the gas having been reversed in the separation chamber; and
a unidirectional flow gas outlet positioned to receive another portion of the gas, from which particles have been separated, from the separation chamber, the direction of this portion of the gas not having been reversed in the separation chamber, wherein the reverse flow gas outlet and the unidirectional flow gas outlet are arranged such that, in operation, the mass flow rate of gas exiting via the reverse flow gas outlet is greater than the mass flow rate of gas exiting via the unidirectional flow gas outlet.
2. A cyclone separator according to claim 1, wherein, in operation, the mass flow rate of gas exiting via the reverse flow gas outlet is over 70% of the total mass flow rate of gas exiting from the cyclone separator.
3. A cyclone separator according to claim 1, wherein, in operation, the mass flow rate of gas exiting via the reverse flow gas outlet is over 95% of the total mass flow rate of gas exiting from the cyclone separator.
4. A cyclone separator according to any one of the preceding claims wherein: the flow area of the reverse flow gas outlet is greater than the flow area of the unidirectional flow gas outlet.
5. A cyclone separator according to any one of the preceding claims, wherein the diameter of the unidirectional gas flow outlet is less than 30% of the diameter of the reverse flow gas outlet.
6. A cyclone separator according to any one of the preceding claims, wherein the diameter of the unidirectional gas flow outlet is in the range of from 1% to 5% of the diameter of the reverse flow gas outlet.
7. A cyclone separator according to any one of the preceding claims, wherein: the shape of a cross section of the reverse flow gas outlet perpendicular to the gas flow direction is circular; and/or
the shape of a cross section of the unidirectional flow gas outlet perpendicular to the gas flow direction is circular.
8. A cyclone separator according to any one of the preceding claims, wherein: the reverse flow gas outlet extends into the separation chamber so as to draw separated gas from inside the separation chamber; and/or
the unidrectional flow gas outlet extends into the separation chamber so as to draw separated gas from inside the separation chamber.
9. A cyclone separator according to any one of the preceding claims, further comprising a solids outlet configured to allow particles, which have been separated from the gas, to exit from the separation chamber, the solids outlet optionally being aligned with the unidirectional flow gas outlet.
10. A cyclone separator according to any one of the preceding claims, wherein at least a part of the separation chamber has an axial centreline, and the inlet either: is substantially parallel to the axial centreline;
is substantially perpendicular to the axial centreline; or
forms a scroll around the axis centreline.
11. A cyclone separator according to any one of the preceding claims, wherein at least a part of the separation chamber has an axial centreline, and the inlet is offset from the axial centreline.
12. A cyclone separator according to any one of the preceding claims, further comprising a second inlet configured to allow the mixture of particles and gas into the separation chamber.
13. A cyclone separator according to claim 12, wherein at least a part of the separation chamber has an axial centreline and the second inlet is either:
substantially parallel to the axial centreline;
substantially perpendicular to the axial centreline; or
forms a scroll around the axis centreline.
14. A cyclone separator according to any one of the preceding claims, wherein: the separation chamber has an inlet end;
the inlet and reverse flow gas outlet are provided at said inlet end; and the unidirectional gas outlet is provided at an end of the separation chamber that is opposite to the inlet end.
15. A cyclone separator according to any one of the preceding claims, wherein: the gas exits the reverse flow gas outlet in a first exit flow direction; and the gas exits the unidirectional flow gas outlet in a second exit flow direction, the first exit flow direction being different to the second exit flow direction.
16. A cyclone separator according to claim 15, wherein the first exit flow direction is substantially opposite to the second exit flow direction.
17. A cyclone separator according to any one of the preceding claims, wherein at least a portion of the separation chamber is radially symmetric about an axial centreline of the separation chamber.
18. A cyclone separator according to claim 17, wherein:
the reverse flow gas outlet comprises a pipe having its centreline substantially aligned with the axial centreline of the separation chamber, and/or
the unidirectional flow gas outlet comprises a pipe having its centreline substantially aligned with the axial centreline of the separation chamber.
19. A cyclone separator according to any one of the preceding claims, wherein at least a portion of the inner wall of the separation chamber is frusto-conical.
20. A method of separating particles from a mixture of gas and particles using the cyclone separator of any one of claims 1 to 19.
21. A method of separating particles from a mixture of gas and particles, said method comprising:
providing the mixture to a separation chamber;
reversing the flow direction of a portion of the gas;
allowing another portion of the gas to continue without reversing its flow direction;
removing the portion of gas whose direction has not been reversed via a unidirectional flow gas outlet; and
removing the portion of gas whose direction has been reversed via a reverse flow gas outlet, wherein
the mass flow rate of gas removed through the reverse flow gas outlet is greater than the mass flow rate of gas removed through the unidirectional flow gas outlet.
22. A method of separating particles from a mixture of gas and particles according to claim 21, wherein the mass flow rate of gas removed through the reverse flow gas outlet is over 70% of the total mass flow rate of gas exiting from the cyclone separator.
23. A method of separating particles from a mixture of gas and particles according to claim 21, wherein the mass flow rate of gas removed through the reverse flow gas outlet is over 95% of the total mass flow rate of gas exiting from the cyclone separator.
24. A method of separating particles from a mixture of gas and particles according to any one of claims 21 to 23, wherein the gas that is not removed through the reverse flow gas outlet is removed through the unidirectional flow gas outlet.
25. A method of separating particles from a mixture of gas and particles according to any one of claims 21 to 24, wherein the position at which the flow direction is reversed is inside the unidirectional flow gas outlet.
26. A method of separating particles from a mixture of gas and particles according to any one of claims 21 to 25, wherein the portion of gas removed via the reverse flow gas outlet is removed in a substantially opposite direction to the portion of gas removed via the unidirectional flow gas outlet.
27. A method of separating particles from a mixture of gas and particles according to any one of claims 21 to 26, wherein the step of separating the mixture comprises centrifugal separation.
28. A method of separating particles from a mixture of gas and particles according to any one of claims 21 to 27, further comprising removing solids separated from the mixture.
29. A method of separating particles from a mixture of gas and particles according to any one of claims 20 to 28, wherein the concentration of particles in the mixture provided to the separation chamber is greater than 1 gm" .
PCT/GB2010/001022 2010-05-21 2010-05-21 Cyclone separator with two gas outlets and separation method WO2011144884A1 (en)

Priority Applications (4)

Application Number Priority Date Filing Date Title
EP10721542.8A EP2571622B1 (en) 2010-05-21 2010-05-21 Cyclone separator with two gas outlets and separation method
PCT/GB2010/001022 WO2011144884A1 (en) 2010-05-21 2010-05-21 Cyclone separator with two gas outlets and separation method
PT107215428T PT2571622E (en) 2010-05-21 2010-05-21 Cyclone separator with two gas outlets and separation method
ES10721542.8T ES2538831T3 (en) 2010-05-21 2010-05-21 Cyclone separator with two gas outlets and separation procedure

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/GB2010/001022 WO2011144884A1 (en) 2010-05-21 2010-05-21 Cyclone separator with two gas outlets and separation method

Publications (1)

Publication Number Publication Date
WO2011144884A1 true WO2011144884A1 (en) 2011-11-24

Family

ID=43513665

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/GB2010/001022 WO2011144884A1 (en) 2010-05-21 2010-05-21 Cyclone separator with two gas outlets and separation method

Country Status (4)

Country Link
EP (1) EP2571622B1 (en)
ES (1) ES2538831T3 (en)
PT (1) PT2571622E (en)
WO (1) WO2011144884A1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2020249824A1 (en) * 2019-06-14 2020-12-17 Scandsib Holdings Ltd Cyclonic evaporator apparatus and associated method

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2816490A (en) * 1952-09-24 1957-12-17 Nichols Engineering And Res Co Apparatus for treating liquid mixtures for separation of solid particles and gases
FR2021978A1 (en) * 1968-10-31 1970-07-24 Celleco Ab
FR2033507A5 (en) * 1969-02-26 1970-12-04 Kloeckner Humboldt Deutz Ag Removal of dust from industrial gases
US3720314A (en) * 1970-11-09 1973-03-13 Aerodyne Dev Corp Classifier for fine solids
US4820414A (en) * 1983-10-06 1989-04-11 Noel Carroll Cyclone separator
US4927298A (en) * 1988-02-22 1990-05-22 Tuszko Wlodzimier J Cyclone separating method and apparatus
WO2010001097A1 (en) * 2008-06-30 2010-01-07 Petroleo Brasileiro S.A. - Petrobras Cyclone separator with two gas outlets and separation method

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2816490A (en) * 1952-09-24 1957-12-17 Nichols Engineering And Res Co Apparatus for treating liquid mixtures for separation of solid particles and gases
FR2021978A1 (en) * 1968-10-31 1970-07-24 Celleco Ab
FR2033507A5 (en) * 1969-02-26 1970-12-04 Kloeckner Humboldt Deutz Ag Removal of dust from industrial gases
US3720314A (en) * 1970-11-09 1973-03-13 Aerodyne Dev Corp Classifier for fine solids
US4820414A (en) * 1983-10-06 1989-04-11 Noel Carroll Cyclone separator
US4927298A (en) * 1988-02-22 1990-05-22 Tuszko Wlodzimier J Cyclone separating method and apparatus
WO2010001097A1 (en) * 2008-06-30 2010-01-07 Petroleo Brasileiro S.A. - Petrobras Cyclone separator with two gas outlets and separation method

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2020249824A1 (en) * 2019-06-14 2020-12-17 Scandsib Holdings Ltd Cyclonic evaporator apparatus and associated method

Also Published As

Publication number Publication date
EP2571622A1 (en) 2013-03-27
PT2571622E (en) 2015-06-17
EP2571622B1 (en) 2015-04-15
ES2538831T3 (en) 2015-06-24

Similar Documents

Publication Publication Date Title
US8657932B2 (en) Cyclone separator and separation method
US6129775A (en) Terminal insert for a cyclone separator
JP3435515B2 (en) Co-current cyclone separator and its application method
CN108786285B (en) Gas-liquid separation device
US7648544B2 (en) Swirl tube separator
EP2247388B1 (en) Separation system and method for separating a fluid mixture with this separating system
EP0360360B1 (en) Swirl tube separator
WO2017191242A1 (en) Cyclone and dip tube for separating a gas
EP1534437B1 (en) Cyclone separator with a vortex extender pin
US20130318933A1 (en) Dynamic cyclone separator, with an axial flow and having a variable configuration
EP2571622B1 (en) Cyclone separator with two gas outlets and separation method
US10792677B2 (en) Cyclone with guide vanes
US20180154375A1 (en) Cyclone separator
EA006032B1 (en) Small highly efficient separator
AU2017272681B2 (en) Cyclone for the separation of particles from a fluid
RU2132750C1 (en) Vortex dust catching method and apparatus
BRPI0805325A2 (en) Gas-solid suspension reverse cyclic separator and separation method
FI80836B (en) Two-phase or multiple-phase cyclone separator or grader
CN111451008A (en) Double-layer shell type efficient cyclone separator
GB2613378A (en) Cyclone device
CA2382059A1 (en) Terminal insert for a cyclone separator

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 10721542

Country of ref document: EP

Kind code of ref document: A1

DPE1 Request for preliminary examination filed after expiration of 19th month from priority date (pct application filed from 20040101)
NENP Non-entry into the national phase

Ref country code: DE

WWE Wipo information: entry into national phase

Ref document number: 2010721542

Country of ref document: EP