WO2018202711A1

WO2018202711A1 - Deflector plate for classifier

Info

Publication number: WO2018202711A1
Application number: PCT/EP2018/061205
Authority: WO
Inventors: Michael Gardiner; Taavi ORUPOLD
Original assignee: Flsmidth A/S
Priority date: 2017-05-03
Filing date: 2018-05-02
Publication date: 2018-11-08

Abstract

A classifier comprising a mixing chamber for locating a slurry; a separation chamber in fluid communication with the mixing chamber to separate solids from the slurry; an inlet fluidly connected to an inlet chamber; at least one de-aeration chamber connected to the inlet chamber, the at least one de-aeration chamber comprising a chute that is fluidly connected to the mixing chamber for allowing slurry from the inlet chamber to make its way to the mixing chamber for further processing after being de-aerated; and at least one deflector plate positioned under the chute, the at least one deflector plate for reducing the velocity of or changing the direction of the slurry as it exits the chute into the mixing chamber.

Description

DEFLECTOR PLATE FOR CLASSIFIER

FIELD OF THE INVENTION The present invention relates to a classifier. In particular, although not exclusively, the present invention relates to a reflux classifier for the separation of materials in mining and mineral processing.

BACKGROUND OF THE INVENTION

The classification of particles according to their size and/or weight is often used in mineral processing. In order to classify these particles it is common to locate the particles in a solution to form a slurry. This slurry is then passed through various types of equipment in order to separate the particles into different sizes and/or densities.

One of these types of equipment is a classifier that separates particles according to their size and/or density. Reflux classifiers, such as the one shown in e.g. U.S. Patent No. 9,421,554, typically have a slurry which is fluidized and passed through a plurality of parallel plates, or lamellae, which use gravity to separate solid particles from the liquid.

While such reflux classifiers have been found to be relatively efficient at separating, it has been found that in certain minerals applications, e.g. mica removal or more generally minerals applications where there are high volumes of material flowing through the classifier, the operating velocities are not optimal.

OBJECT OF THE INVENTION

It is an object of the invention to overcome or at least alleviate one or more of the above problems and/or provide the consumer with a useful or commercial choice.

SUMMARY OF THE INVENTION

A classifier is provided which has a mixing chamber for locating a slurry; a separation chamber in fluid communication with the mixing chamber to separate solids from the slurry; an inlet fluidly connected to an inlet chamber; at least one de-aeration chamber connected to the inlet chamber, the at least one de-aeration chamber comprising a chute that is fluidly connected to the mixing chamber for allowing slurry from the inlet chamber to travel to the mixing chamber for further processing after being de-aerated; at least one deflector plate positioned under the chute, the at least one deflector plate for reducing the velocity of or changing the direction of the slurry as it exits the chute into the mixing chamber.

In an exemplary embodiment of the classifier, the deflector plate is comprised of a base plate; two angled side plates connected to the base plate; one or more attachment means for attaching the deflector plate onto the chute, the attachment means being affixed to the lateral ends of the base plate and to the two angled side plates. In some embodiments, the deflector plate is a single integral piece.

In an exemplary embodiment of the classifier, the deflector plate is curved or bowl-shaped such that a thickness of a middle portion of the deflector plate is less than a thickness of a first and a second end portion of the deflector plate. In some embodiments, a longitudinal thickness of the first and second end portions is between 10-150 mm.

Other details, objects, and advantages of the invention will become apparent as the following description of certain present exemplary embodiments thereof and certain present exemplary methods of practicing the same proceeds.

BRIEF DESCRIPTION OF THE FIGURES

Embodiments of the invention, by way of example only, will be described with reference to the accompanying drawings in which:

Figure 1 is a perspective view of a classifier, which is taken from U.S. Patent No. 9,421,554, to show an embodiment of the basic construction of the apparatus with which the present invention is concerned;

Figure 2 is a perspective view of the classifier shown in Figure 1, with its cover removed;

Figure 3 is a side elevation view of the classifier illustrated in Figure 2;

Figure 4 is a front elevation view of the classifier illustrated in Figure 2;

Figure 5 is a side elevation cross sectional view of the classifier illustrated in Figure 1; Figure 6 is a perspective cross sectional view of the classifier illustrated in Figure

1 ; and

Figure 7 is another side elevation cross sectional view of the classifier illustrated in Figure 1 ;

Figure 8 is a perspective cross sectional view of the classifier illustrated in Figure

1 with the present invention added; and

Figure 9 is a bottom view of the classifier of Figure 8 showing the features of the present invention. DETAILED DESCRIPTION OF THE INVENTION

Figures 1 and 5 to 7 illustrate a first embodiment of a classifier and figures 2 to 4 illustrate a second embodiment of the classifier. The two embodiments are similar with the first embodiment illustrating a cover 101 and the second embodiment being generally larger than the first and having no cover illustrated. Like numbering is used to describe common features between the two embodiments and they will therefore be referred to simultaneously.

Figures 1 to 7 illustrate two embodiments of a classifier in the form of a reflux classifier 100 used to separate material, such as coal particles, on the basis of size and weight. The reflux classifier 100 has a separation chamber in the form of a lamella chamber 110 located on top of a mixing chamber 120 which is located above a fluidizing chamber 130. The reflux classifier 100 is illustrated on a stand 200 which is typically removed after installation.

The lamella chamber 110 has an inlet 111 and an outlet 112 and is in fluid communication with the mixing chamber 120 and the fluidizing chamber 130. The lamella chamber 110 may be formed of a plurality of separable parts. In the illustrated embodiments of the reflux classifier 100 the lamella chamber 110 is formed from two portions, namely a first part 110A having a first portion of a housing 113A and a second part HOB having a second portion of a housing 113B. Together the two portions 11 OA and HOB form a complete lamella chamber 110. Both the first and second portions of housing 113A and 113B have supports 114A and 114B, respectively, that can be used to mount the reflux classifier 100 to an external structure (not shown). The first part 110A and second part HOB of the lamella chamber 110 each have a mounting system, in the form of corresponding flanges 115 (illustrated together in the figures), to affix the two portions together as shown. The flanges 115 each have a plurality of apertures (not shown) that receive fasteners in the form of nuts and bolts. The inlet 111 and outlet 112 are both located along the seam between the first part 11 OA and second part HOB of the lamella chamber 110 and can be used to further affix first part 11 OA and second part HOB of the lamella chamber 110 together for use. If the first part 11 OA and second part 1 10B of the lamella chamber 110 are not to be separated again after installation, more permanent methods of affixing may be utilized instead of, or as well as, flanges 115 with nuts and bolts.

The lamella chamber 110 has a series of plate arrays in the form of a plurality of parallel plates 116 (see figure 2). The plurality of parallel plates 116 are split between the first part 11 OA and second part HOB of the lamella chamber 110 to form a first set of parallel plates 116A in the first part 11 OA and a second set of parallel plates 116B in the second part HOB. The parallel plates 116 are inclined relative to the axis of gravity to provide a classifying effect to material that passes through the plates 116. As can be seen in figure 2 the first set of parallel plates 116A is inclined in an opposite direction to the second set of parallel plates 116B.

A plurality of launders 117 are provided in each of the first part 110A and second part HOB of the lamella chamber 110 to catch particles located within the slurry after it has passed through the plurality of parallel plates 116. Each launder 117 has two substantially parallel side walls and an inclined base. The launders 117 are fluidly connected to a collector 118 which is located centrally between the first set of parallel plates 116A and the second set of parallel plates 1 16B. The collector 118 is generally 'V shaped and receives material, such as coal slurry, once it has passed through the launders

117. The collector 118 is fluidly connected to the outlet 112 which enables processed material to exit the reflux classifier 100 from the collector 118.

The mixing chamber 120 has a hatch 121 that allows access therein for cleaning and maintenance, or the like. The fluidizing chamber 130, which keeps slurry in a fluid state, has an underflow valve 131. The underflow valve 131 is located adjacent the bottom of the fluidizing chamber 130 for removal of heavier particles and solids.

The lamella chamber 110 is mounted to the mixing chamber 120 by way of flanges with nuts and bolts. This allows the lamella chamber 110 to be separated from the mixing chamber 120. The same applies between the mixing chamber 120 and the fluidizing chamber 130 which allows the reflux classifier 100 to be broken down into smaller pieces for transportation, or the like.

Figures 5 to 7 illustrate cross sectional views of the reflux classifier 100 where various internal components can be seen more clearly. The inlet 111 is fluidly connected to an inlet chamber 150 which has a plurality of de-aeration chambers 151 connected thereto. The de-aeration chambers 151 each have a chute 152 that is fluidly connected to the mixing chamber 120 allowing slurry from the inlet chamber 150 to make its way to the mixing chamber 120 for further processing after being de-aerated.

Figures 8 and 9 illustrate deflector plates 200 of the present invention. As shown, the deflector plates 200 are located within the mixing chamber and are positioned under one or more of the respective chutes 152 in order to change or reduce the velocity and direction of the feed as it flows through the chute(s) 152 of the de-aeration chamber(s) 151 into the mixing chamber 120. By altering the velocity and direction of the material in high volume applications, it has been found that feed blockages can be minimized and constant velocities can be maintained. In one embodiment, each of the deflector plates is comprised of a base plate 201, two angled side plates 202a, 202b which are connected to the longitudinal sides of the base plate 201 and one or more attachment means 203 for attaching the deflector plate 200 onto the chute 152. The one or more attachment means 203 can be affixed to the lateral ends of the base plate 201 and two angled side plates 202a, 202b in order to affix the deflector plate 200 onto the chutes 152 via e.g. bolting or fastening. In some embodiments the deflector plates 200 are a single integral piece, in other embodiments the base plate 201, angled side plates 20a, 202b and/or the one or more attachment means 203 can be manufactured as unitary pieces and thereafter be attached to each other via e.g. welding. In some embodiments, the deflector plate 200 is comprised of a plate which may include one or more attachment means 203 for attaching the deflector plate 200 onto the chute 152. In some embodiments, the surface of the deflector plate 200 which faces the chutes 152 is curved or bowl-shaped such that a thickness of a middle portion of the deflector plate 200 is less than the thickness of the end portions of the deflector plate 200. In some embodiments, a longitudinal thickness of the end portions is between 10-150 mm.

A top of each de-aeration chamber 151 is inclined, defined by an inclined base of respective launders 117 located directly above the de-aeration chambers 151. An inclined de-aeration face 153, as seen in figure 7, urges lighter air particles upwards, toward an air outlet 154 at the top of the de-aeration chamber 151. An air pipe 155 is connected to the air outlet 154 and is fluidly connected to the respective launders to allow air particles to bypass the mixing chamber 120 and lamella chamber 1 10. It should be appreciated that the tops of the de-aeration chambers 151 need not be formed from the inclined bases of the respective launders 40 and may be formed irrespective of the launders 40. That is, the de-aeration faces 153 may be formed by other means.

The mixing chamber 120 receives material to be processed, such as mineral slurry, from an open bottom of the de-aeration chambers 151. The mixing chamber 120 can then deliver the material to the lamella chamber 110. Fluidizing chamber 130 ensures that material in the mixing chamber 120 remains in a fluid state for processing.

In use, the reflux classifier 100 can be transported in separate parts and put together on site relatively easily. Once installed, material to be separated, such as coal slurry, is fed into the inlet 111 where it is processed by the reflux classifier 100. Specifically, the material to be processed is passed from inlet 111 to inlet chamber 150 and then distributed to any one of a plurality of de-aeration chambers 151. Any air in the material rises and is urged toward air outlet 154 by inclined faces 153 of the de-aerators 151, from where it is transferred to the launders 117 by air pipes 155.

From the de-aeration chambers 151 the material then travels down chutes 152, is redirected by deflector plates 200, and then enters into the mixing chamber 120, located below the lamella chamber 110. The slurry is then fluidized by the fluidizing chamber 130 and then passes upwardly through the parallel plates 116 of the lamella chamber 110 where particles located within the coal slurry are sorted according to size and weight. Heavy and large particles pass into the bottom of the mixing chamber 120 where they can be removed through underflow valve 131 into a tundish (not shown) or similar. The lighter and smaller particles are able to pass through the plates 116 where they pass into the launders 117, into the collector 118 and out of the outlet 112.

Advantageously, the reflux classifier 100 can be separated into manageable parts for transportation and then constructed on site. This can provide more flexibility for transportation and can significantly reduce transportation costs. Furthermore, it may enable the reflux classifier 100 to be used in situations where it could not otherwise be used due to size restrictions on transportation. Similar improvements can be found in decommissioning the reflux classifier 100 as it is more manageable to disassemble and remove from site.

The opposing arrangement of parallel plates 116A and 116B allows a single collector 118 and outlet 112 to be used despite the two separate sets of parallel plates 116A and 116B with associated launders 117. The centrally located inlet chamber 150 and collector 118 allow for more de-aeration chambers 151 and launders 117 to be provided than would otherwise be possible without having multiple inlets and outlets and increased complexity. Furthermore, the integrated de-aeration chambers 151 in the separable lamella chamber 110 allows for removal of air particles from material to be processed, providing better separation of solids and generally improving throughput and efficiency of the reflux classifier 100.

It is to be understood that the form of this invention as shown is merely a preferred embodiment. Various changes may be made in the function and arrangement of parts; equivalent means may be substituted for those illustrated and described; and certain features may be used independently from others without departing from the spirit and scope of the invention as defined in the following claims.

Claims

1. A classifier comprising:

a mixing chamber (120) for locating a slurry;

a separation chamber (110) in fluid communication with the mixing chamber

(120) to separate solids from the slurry;

an inlet (111) fluidly connected to an inlet chamber (150);

at least one de-aeration chamber (151) connected to the inlet chamber (150), the at least one de-aeration chamber (151) comprising a chute (152) that is fluidly connected to the mixing chamber (120) for allowing slurry from the inlet chamber (150) to travel to the mixing chamber (120) for further processing after being de-aerated;

at least one deflector plate (200) positioned under the chute (152), the at least one deflector plate for reducing the velocity of or changing the direction of the slurry as it exits the chute (152) into the mixing chamber (120).

2. The classifier of claim 1, wherein the deflector plate (200) is comprised of:

a base plate (201);

two angled side plates (202a, 202b) connected to the base plate (201);

one or more attachment means (203) for attaching the deflector plate onto the chute (152), the attachment means (203) being affixed to the lateral ends of the base plate

(201) and to the two angled side plates (202a, 202b).

3. The classifier of claim 2, wherein the deflector plate (200) is a single integral piece.

4. The classifier of claim 1, wherein the deflector plate (200) is curved or bowl- shaped such that a thickness of a middle portion of the deflector plate 200 is less than a thickness of a first and a second end portion of the deflector plate 200. 5. The classifier of claim 4, wherein a longitudinal thickness of the first and second end portions is between 10- 150 mm.

6. The classifier of claim 1, wherein the separation chamber (110) has a first portion (110A) and a second portion (110B);

wherein each of the first portion (110A) and the second portion (HOB) contain a series of plate arrays (116); and

wherein the plate arrays (116) of each portion are inclined in opposed directions.

7. The classifier (100) of claim 1, wherein the classifier (100) further comprises a fluidizing chamber (130) connected to the mixing chamber (120).

8. The classifier (100) of claim 1, wherein the separation chamber (110) comprises at least one launder (117). 9. The classifier (100) of claim 1, wherein the separation chamber (110) further comprises an outlet (112).

10. The classifier (100) of claim 1, wherein the separation chamber (110) further comprises an inlet (111).