Cyclonic separating apparatus

ES 2 265 036 T3

DESCRIPTION

Cyclonic separation apparatus.

This invention relates to a cyclonic separation apparatus. In particular, but not exclusively, this invention relates to a cyclonic separation apparatus for use in vacuum cleaners.

The cyclonic separation apparatus is well known and is used in a wide variety of applications. In the last decade or so, the use of cyclonic separation apparatuses to separate particles from an air stream in a vacuum cleaner has been developed and commercialized. Detailed descriptions of cyclonic separation apparatus for use in vacuum cleaners are presented in US 3,425,192, US 4,373,228 and EP 0 042 723, among others. From these and other prior art documents it can be seen that it is known to provide two cyclone units in series so that the air stream passes sequentially through at least two cyclones. This allows dirt and larger debris to be removed from the air stream in the first cyclone and the second cyclone to operate under optimal conditions, effectively separating very fine particles in an efficient manner. This type of arrangement has been found to be effective when dealing with air currents that carry a variety of materials with a wide particle size distribution. This is the case with vacuum cleaners.

It is also desirable that vacuum cleaners are both compact and energy efficient. Another desirable feature is a large capacity to collect dirt and debris to reduce the frequency of emptying. In some known arrangements, the downstream cyclone is located within the upstream cyclone in an attempt to minimize the dimensions of the vacuum cleaner (see, for example, US 4,373,228 and EP 0 042 723). However, this reduces the capacity of the vacuum cleaner because the downstream cyclone occupies space that would otherwise be available for accumulation of dust and dirt. In arrangements of the type described in US 3,425,192, the downstream cyclones are located outside of the upstream cyclone but the partially clean air exiting the upstream cyclone must travel some distance to the inlets of the downstream cyclones. This increases the pressure drop across the entire system and therefore reduces the energy efficiency of the system.

Furthermore, the volume of the means for conducting the partially clean air increases the overall volume of the machine.

It is also known from DE 615004C to provide apparatus for cyclonic dust separation in which the outlet of a cyclone is configured in such a way that it performs a secondary cleaning action on the outlet air.

It is an object of the present invention to provide a cyclonic separation apparatus which has an improved ability to accumulate separated particles and better energy efficiency. It is another object of the invention to provide a cyclonic separation apparatus suitable for use in vacuum cleaners and capable of achieving improved performance compared to the prior art. It is still another object of the invention to provide a cyclonic separation apparatus capable of mitigating the disadvantages of the prior art.

The invention provides a cyclonic separation apparatus comprising an upstream cyclonic unit and a downstream cyclonic unit, wherein the upstream cyclonic unit comprises at least one cyclone having a first end and a second end, and the cyclonic unit downstream comprises at least one cyclone having a first end and a second end, and the upstream and downstream cyclone units are arranged relative to each other such that the orientation of the at least one cyclone of the downstream cyclone unit is substantially reversed with respect to the orientation of the at least one cyclone. of the upstream cyclone unit, characterized in that the downstream cyclone unit comprises a plurality of cyclones arranged in parallel.

Reversing the downstream cyclonic unit relative to the upstream cyclonic unit allows the cyclone units to be arranged in a way that reduces the length of the air stream path between the upstream cyclonic unit and the upstream cyclonic unit. downstream, particularly when the downstream cyclonic unit is located outside of the upstream cyclonic unit. This means that the pressure drop across the entire appliance can be kept to a minimum, which increases the energy efficiency of the appliance, while the storage capacity of the appliance is kept as high as possible.

In a preferred embodiment, the downstream cyclone unit is located outside of the upstream cyclone unit and the two cyclone units are arranged so that they are substantially vertical with the first end of the cyclone or each cyclone of the cyclone unit. highest upstream and the first end of each downstream cyclone unit cyclone downstream. Thus, the outlet of the cyclone or of each cyclone of the upstream cyclone unit is located near the inlet of each cyclone of the downstream cyclone unit. This manages to minimize the length of the air stream path between the cyclone units so that losses are minimal. The second end of each cyclone of the downstream cyclone unit projects away from the upstream cyclone unit rather than being located within the upstream cyclone unit. This maximizes the ability of the upstream cyclone unit to accumulate dirt and debris and therefore reduces the frequency with which the upstream cyclone unit must be emptied.

A preferred characteristic of the mentioned embodiment is that the cyclones of the downstream cyclone unit are inclined relative to each other so that said cyclones approach each other at the second ends thereof. This arrangement makes it more difficult for fine particles of separated dirt and dust to be deposited on the outer surfaces of the cyclones of the upstream cyclone unit.

It is preferable that the apparatus according to the invention is incorporated in a vacuum cleaner, preferably a household vacuum cleaner. This is because the combined advantages of higher storage capacity and lower pressure drop are particularly useful in a vacuum cleaner. The user perceives the benefits

ES 2 265 036 Features of lower energy consumption and less frequency in emptying procedures.

Other preferred features are set out in the subsidiary claims.

Examples of embodiments of the invention are described below with reference to the attached illustrations, in which:

Figures 1a and 1b are front and side views, respectively, of a vacuum cleaner incorporating the cyclonic separation apparatus according to the invention;

Figures 2a, 2b and 2c are front, side and elevation views, respectively, of a first embodiment of a cyclonic separation apparatus that forms part of the vacuum cleaner of Figures 1a and 1b;

Figures 3a and 3b are front and sectional views, respectively, of the cyclonic separation apparatus of Figures 2a, 2b and 2c, and Figure 3b is taken on the line III-III of Figure 3a;

Figures 4a, 4b and 4c are perspective, elevation and section views, respectively, of a part of the cyclonic separation apparatus of Figures 2a, 2b and 2c, and Figure 4c is taken on line IVIV of Figure 4b;

Figure 5 is a sectional view of the cyclonic separation apparatus of Figures 2a, 2b and 2c taken on the line VV of Figure 2b;

Figure 6 is a schematic side view of a second embodiment of a cyclonic separation apparatus according to the invention and suitable for use in a vacuum cleaner; and Figure 7 is a schematic side view of a third embodiment of a cyclonic separation apparatus according to the invention and suitable for use in a vacuum cleaner.

Figures 1a and 1b show a household vacuum cleaner 10 incorporating a cyclonic separation apparatus according to the present invention. The vacuum cleaner 10 comprises a vertical body 12 at a lower end of which a housing for the motor is located

14. A cleaning head 16 is hingedly mounted on the motor housing 14. A suction inlet 18 is provided on the cleaning head 16 and wheels 20 are rotatably mounted on the motor housing 14 to allow movement of the vacuum cleaner. 10 on a surface to be cleaned.

The cyclonic separation apparatus 100 is mounted on the vertical body 12 above the motor housing 14. The cyclonic separation apparatus 100 rests on a generally horizontal surface formed by a filter cover 22. The filter cover 22 is located on the motor housing 14 and provides a cover for a post-motor filter (not shown). The cyclonic separation apparatus 100 is also attached to the vertical body 12 by means of a clamp 24 located atop the cyclonic separation apparatus 100. The vertical body 12 incorporates upstream ducts (not shown) to carry the dirty air. to an inlet of the cyclonic separation apparatus 100 and downstream ducts 26 to bring the already clean air out of the cyclonic separation apparatus 100.

The upright body 12 further includes a hose and stem assembly 28 that can be retained in the configuration shown in the illustrations to serve as a handle for moving the vacuum 10 over a surface to be cleaned. Alternatively, the hose and stem assembly 28 can be detached to allow the distal end 28a of the stem to be used in conjunction with a floor tool (not shown) to perform a cleaning function, for example on stairs, upholstery, etc. The structure and operation of the hose and stem assembly 28 are not relevant to the present invention and will not be described in more detail here. The general structure and operation of the hose and stem assembly 28 illustrated in Figures 1a and 1b are similar to those described in US Patent No. Re 32,257, which is included herein by reference. Also, various tools and accessories 30a, 30b, 30c are removably mounted to the vertical body 12 for storage purposes between periods of use.

The precise details of the features of the vacuum cleaner 10 described above are not relevant to the present invention. The invention relates to the details of the cyclonic separation apparatus 100 that is part of the vacuum cleaner 10. In order for the cyclonic separation apparatus 100 to come into operation, the motor located in the motor housing 14 is activated so that the air is drawn into the vacuum cleaner through either the suction inlet 18 or the distal end. 28a from the hose and stem assembly 28. This dirty air (since it is air that carries dust and dirt with it) passes to the cyclonic separation apparatus 100 through the upstream ducts. Once the air has passed through the cyclonic separation apparatus 100, it is conducted out of the cyclonic separation apparatus 100 and down the vertical body 12 to the motor housing 14 through the downstream ducts 26. The air Clean is used to cool the motor located in the motor housing 14 before being ejected from the vacuum cleaner 10 through the filter cover 22.

This principle of operation of the vacuum cleaner 10 is known from the prior art. This invention relates to the cyclonic separation apparatus 100 which is illustrated in Figures 2a, 2b and 2c in isolation from the vacuum cleaner 10.

The cyclonic separation apparatus 100 illustrated in Figure 2 comprises an upstream cyclone unit 101 comprised of a single upstream cyclone 102 and a downstream cyclonic unit 103 comprised of a plurality of downstream cyclones 104. The downstream cyclone 104. Upstream 102 is essentially made up of a cylindrical container 106 having a closed base 108. The open upper end 110 of the cylindrical container is in contact with a circular upper molding 112 that defines an upper end of the upstream cyclone 102. In the cylindrical container 106 an inlet opening 104 is provided to allow introduction of dirty air into the interior of the upstream cyclone 102. Inlet opening 104 is shaped, positioned, and configured to communicate with the upstream conduit that carries dirt-laden air from cleaner head 16 to cyclonic separation apparatus 100. In cylindrical container 106 and circular trim 112 respectively a handle 116 and a catch 118 are provided in order to provide means for releasing the cylindrical container 106 from the circular molding 112 when it is necessary to empty the cylindrical container 106. If necessary, a seal (not shown) can be provided between the cylindrical container 106 and the circular trim 112.

ES 2 265 036 T3

The cylindrical container base 18 may be hingedly connected to the rest of the cylindrical container to provide additional access to the interior of the cylindrical container 106 for emptying purposes. The exemplary embodiment illustrated herein will include a mechanism to allow the base 108 to be hinged open to allow emptying, but details of such mechanism are the subject of a copending application and will not be described further here.

Seven identical downstream cyclones 104 are fed into the downstream cyclonic unit 103. The downstream cyclones 104 are equiangularly spaced about the central longitudinal axis 150 of the downstream cyclonic unit 103, which is coincident with the longitudinal axis. of the upstream cyclonic unit 101. This arrangement is illustrated in Figure 2c. Each downstream cyclone 104 is frusto-conical in shape with the widest end thereof located at the lowest position and the narrowest end at the top. Each downstream cyclone 104 has a longitudinal axis 148 (see Figure 3b) that is slightly inclined towards the longitudinal axis 150 of the downstream cyclone unit 103. This feature is described in more detail below. Furthermore, the outermost point of the lowermost end of each downstream cyclone 104 extends radially further from the longitudinal axis 150 of the downstream cyclone unit 103 than the wall of the cylindrical container 106. The uppermost ends of the cyclones of downstream 104 project into a collection trim 120 that extends upwardly from the surfaces of the downstream cyclones 104. The collection molding 120 supports a handle 122 that allows the entire cyclonic separation apparatus 100 to be transported. In the handle 122 a retainer 124 is provided for the purpose of fixing the cyclonic separation apparatus 100 to the vertical body 12 at the upper end thereof. . An outlet opening 126 is provided in the upper trim 112 to conduct the already clean air out of the cyclonic separation apparatus 100. The outlet opening 126 is arranged and configured to cooperate with the downstream duct 26 to bring the already clean air into the motor housing 14.

The collection trim 120 also carries an actuator lever 128 designed to activate a mechanism for opening the base 108 of the cylindrical container 106 for emptying purposes, as mentioned above.

The internal characteristics of the cyclonic separation apparatus 100 are described below with reference to FIG. 3b. Figure 3a corresponds to Figure 2a and indicates the line III-III on which the section of Figure 3b has been taken.

The internal features of the upstream cyclone 102 include an internal wall 132 that extends the entire length thereof. The interior space defined by the internal wall 132 communicates with the interior of the collection trim 120, as described below. The purpose of the inner wall 132 is to define a collection space 134 for the fine dust. Located within internal wall 132 and in collection space 134 are components to allow base 108 to open when actuator lever 128 is actuated. The precise details and operation of these components are not relevant to the present invention and they are not described in more detail here.

Mounted on the outside of the inner wall 132 are four equally spaced baffles or fins 136 that project radially outward from the inner wall 132 towards the cylindrical container 106. These baffles 136 favor the deposit of large particles of dust and dirt in the space. collection box 138 defined between inner wall 132 and cylindrical container 106 adjacent base 108. The particular characteristics of the baffles 136 are described in more detail in WO 00/04816.

Located on the exterior of inner wall 132 at a top of upstream cyclone 102 is a fairing 140. The fairing extends upward from baffles 136 and, together with inner wall 132, defines an air passage 142. The fairing 140 has a perforated portion 144 that allows air to pass from inside the upstream cyclone 102 to the air passage 142. The air passage 142 communicates with the inlet 146 of each of the downstream cyclones 104. Each inlet 146 is arranged in a roll fashion so that the air entering each downstream cyclone 104 is forced to follow. a helical path within the respective downstream cyclone 104.

As mentioned above, the longitudinal axis 148 of each downstream cyclone 104 is inclined towards the longitudinal axis 150 of the downstream cyclone unit 103. The upper end of each downstream cyclone 104 is closer to the longitudinal axis 150 than the lower end of it. In this exemplary embodiment, the angle of inclination of the relevant axes 148 is substantially 7.5 °.

The upper ends of the downstream cyclones 104 project into the collection trim 120, as mentioned above. The interior of the collection trim 120 defines a chamber 152 with which the upper ends of the downstream cyclones 104 communicate. Within chamber 152, a plurality of generally radially extending fins 153 project downwardly from upper surface 121 of collection trim 120 (see FIG. 5). The flaps 153 extend inwardly from the outer wall 123 of the collection trim 120 to an inner wall 129 that surrounds the mechanism for opening the base 108 of the cylindrical container 106 for emptying purposes. The fins 153 project downward to a level below the upper ends of the cyclones 104. This arrangement prevents any dirt and dust that exits the upper end of one of the cyclones 104 from moving into an adjacent cyclone and penetrating in it by its open upper end. If that were to happen, there would be a risk that dirt and dust already separated from the air stream by the first cyclone would re-enter the air stream through the adjacent cyclone.

The collection trim 120 and the surfaces of the downstream cyclones 104 together define an axially extending passageway 154, located between the downstream cyclones 104, which communicates with the collection space 134 defined by the inner wall 132. In this way it is possible that dirt and dust exiting the narrower ends of the downstream cyclones 104

ES 2 265 036 T3 pass from chamber 152 into collection space 134 through passageway 154.

Each downstream cyclone 104 has an air outlet in the form of an upper overflow nozzle 156 (or vortex finder). Each upper overflow nozzle 156 is centrally located at the lowermost end of the respective downstream cyclone 104, as is the norm. In this exemplary embodiment, a central body 158 is located on each upper overflow nozzle 156. Each upper overflow nozzle communicates with an annular chamber 160 which, in turn, communicates with the outlet opening 126 (see FIG. 2c).

Figures 4a, 4b and 4c illustrate the arrangement of the downstream cyclones 104 in greater detail. In particular, this figure helps to illustrate the configuration of passageway 154. Figure 4b also helps to illustrate the fact that the side of each of the downstream cyclones 104 closest to the longitudinal axis of the downstream cyclone unit 103 it lies substantially parallel to it.

The mode of operation of the apparatus described is as follows. Dirty air (air that carries dust and dirt) enters the cyclonic separation apparatus through the inlet opening 114. The arrangement of the inlet opening 114 is essentially tangential to the wall of the cylindrical container 106, causing it to the inlet air follows a helical path around the inside of the cylindrical container 106. Larger dust and dirt particles, along with lint and other large debris, are deposited in the collection space 138 adjacent to the base 108 by the effect of centrifugal forces acting on the particles, as is well known. Partially clean air travels inward and upward away from base 108, and exits upstream cyclone 102 through perforated portion 144 of fairing 140. The partially clean air then moves through the air passage 142 where it is divided into seven parts. Each part enters one of the downstream cyclones 104 through the respective opening 146. As mentioned above, each opening 146 is a coil-shaped inlet that forces the incoming air to follow a helical path within the cyclone of downstream 104. The conical shape of the downstream cyclone 104 causes additional intense cyclonic separation within the downstream cyclone 104 such that very fine dust and dirt particles are separated from the main air stream. Dust and dirt particles exit the upper end of the cyclone

104 downstream while the clean air returns to the lower end of the downstream cyclone 104 along the axis 148 thereof and exits through the upper overflow nozzle 156. The clean air passes from the upper overflow nozzle 156 to the chamber annular 162 and from there to outlet opening 126. Meanwhile, dust and dirt that have been separated from the air stream in downstream cyclone 104 falls from chamber 152 through passageway 154 into collection space 134. Flaps 153 prevent it from passing to the upper end. open from adjacent cyclones 104.

When it is desired to empty the cyclonic separation apparatus 100, the base 108 can be separated on its hinges from the side wall of the cylindrical container 106 so that dirt and debris accumulated in the collection spaces 134 and 138 can fall into a suitable receptacle. . As explained above, the detailed operation of the emptying mechanism does not form part of the present invention and will not be described in more detail here.

The invention is not limited to the precise details of the embodiments described above. It is necessary to underline that the characteristics of the vacuum cleaner in which the cyclone separator is to be used are not significant for the invention. In fact, it is envisaged that cyclonic separation apparatus of the type described herein can be used for other applications where good separation efficiency combined with low pressure drops is required. Also, there is no particular need for the apparatus to be arranged so that the axes of the cyclone units are vertical, and in fact the axes can be inclined relative to the vertical and even be horizontal if desired. The fact that centrifugal separation is not greatly affected by gravity allows these arrangements as long as the collection areas of the cyclone units are arranged to collect the debris without interfering with the air stream paths necessary to effect the separation. . In another variation of the above-described embodiments described in detail, the downstream cyclones illustrated in Figures 1 to 5 can be arranged so that their respective axes are arranged parallel to each other instead of being inclined towards the axis of the downstream cyclonic unit as shown in the illustrations. Other variations and modifications will be apparent to the skilled reader.