FI114382B - Central vacuum cleaner dust extraction method and arrangement - Google Patents

Description

, 11438?

Central vacuum cleaner column separation method and arrangement

The present invention relates to a method 5 for removing solids from an air stream to a central vacuum cleaner according to the preamble of claim 1.

According to such a method, the solid is separated from the dusty stream of air in two steps whereby the stream of air is first introduced into a cyclone, after which the pre-purified stream of air is led to a second separator for removing finely divided solid.

10

The invention also relates to a dust separation arrangement according to the preamble of claim 7.

In central vacuum cleaners, the solids are degassed with a series-connected 1-hole cyclone and a paper filter. The present structure is shown in Fig. 1, where 15 denotes the separator vessel wall with reference numerals 1a and Ib, cyclone 2 inlet 3 and exhaust air outlet 4. The inner wall of the separation tank forms a cyclone separation chamber. The separating vessel Ib forms a separate vessel which can be detached to discharge dust collected at the shrink collar 8. The paper filter is designated as 5. Previously, a foam filter was used to replace the paper filter. Thereafter, the air passes through a 2-stage high speed blower 6 and either to the side of the electric motor '' or directly to the open air. If this exhaust air passes to the side of the electric motor: '' it also cools the motor. The cyclone-separated coarse solid is collected • · «'· J: to the bottom of the separation tank 7. The solid path from the wall of the cyclone separation chamber to the bottom of the tank is indicated by an arrow. A truncated conical collar 8 is usually provided in the center of the tank 25 to prevent dust accumulation of the collected solid. The cyclone and fan space are separated by a partition 9 through which an outlet 10 is connected, which is connected '. on the suction side of the central vacuum cleaner fan.

There are drawbacks to the prior art. Thus, 1-hole cyclone does not remove dust well and! .. '30 much of the dust is found on the surface of the filter. Fouling of the filter will reduce 4 · suction power as the operating time progresses. Failure to clean the filter will result in • · 'engine cooling and overheating may result in engine damage. After a period of use, usually one year, the filter cartridge has to be replaced because the pores in the 114382 filter paper gradually become clogged despite cleaning. This creates a continuous running cost.

The object of the present invention is to eliminate the drawbacks of the prior art and to provide a novel solution for separating and recovering dust and the like solid from an air stream entering the central vacuum cleaner or the like where separation of a finely divided and partially quite light

The invention is based on the idea that the separation of solids takes place in two separation steps, whereby the prior art separates the coarse material with a single orifice cyclone, followed by a multiple orifice cyclone as the separation element. Surprisingly, it has been found that by using a multi-gap cyclone in a second separation step, the finely divided solid can be effectively separated without reducing suction power due to filter clogging. In addition, the pressure difference across the cyclone is usually smaller than the pressure difference over a clean filter, so more suction power is available initially. The economic advantage is that the cyclone solution does not require replacement parts during life (filter cartridge).

More specifically, the process of the invention is essentially '; * 'Is characterized by what is set forth in the characterizing part of claim 1.

s * t ·

The process according to the invention, in turn, is characterized by what is represented by i * ''. in the characterizing part of claim 7.

»· 25 • ·

The invention provides significant advantages. Thus, a multiple aperture cyclone can be readily obtained; installs a central vacuum cleaner for solids removal without separating the device structure. ' · *. would need to change. The multi-aperture cyclone can be placed in a single-aperture cyclone and filter I · '. or can completely replace the filter. The multi-aperture cyclone provides !!! m 30 a continuously regenerating filtration surface for collecting the separated solids in its own »t '· * collection container. The hardware solution is suitable for other applications where • * * • · ·; it is desired to remove solids from the suction side of the fan before the fan. These include e.g.

* * · T · dust removal equipment for the carpentry industry.

3, 114382

The invention will now be further explored by means of a detailed description with reference to the accompanying drawings.

Figure 1 is a cross-sectional side elevational view of the prior art separation device 5, Figure 2 is a schematic view of a first preferred embodiment of the invention, Figure 3 shows a solution having a prior art separation device between a single orifice cyclone and 10 top view of the structure of a multi-aperture cyclone separation chamber with impellers.

The multi-aperture cyclone is described e.g. U.S. Patent 3,969,096. By a multi-hole cyclone is meant a cyclone having at least two inlets for introducing a gas stream 15 into the cyclone separation chamber. The apertures are preferably symmetrically spaced relative to the separation chamber.

2 shows a dust extraction arrangement for a central vacuum cleaner comprising a separating device 11a, 11b arranged between the suction pipe and the fan. The apparatus comprises a first-stage coarse solid consisting of a conventional single-aperture cyclone 12. 20, as well as the fine solids of the multi-aperture cyclone 13. Like I '. it is shown in the figure that the dusty air stream is first led through the inlet 14 to the single-aperture cyclone 12 and then to the multi-aperture cyclone 13. The multi-aperture cyclone is: ''; placed inside a single-aperture cyclone separation chamber. The separation chamber of the single-aperture cyclone 12 is cylindrical and the inlet 15 of the multi-aperture cyclone is in the downstream direction. φ: 25 annular cross-sections relative to the center axis of the assembly. A dusty air stream is introduced into the single-aperture cyclone separation chamber above the inlet of the multi-aperture cyclone: '·. In this way it is possible to prevent the "" short circuit "of the separation devices, in which the airflow passes directly to the multi-aperture cyclone. The multi-aperture cyclone separation chamber is closed from above; ·: Annular plate 16 through which an outlet 17 is connected, connected:, t, · 30 to the suction side of the fan 18 of the central vacuum cleaner. Purified air exits at the outlet 25 • '· *; through. The separation device is divided into two parts 11a, 11b by a collar 27.

•: "· The shrink collar 27 is useful, especially if the separation tank is low. The lower section 1b of the separation tank forms a removable container for emptying the collected dust. The lower leg 20 of cyclone 4 114382 is

The multi-aperture cyclone 13 used in the invention (see FIG. 4) has a separation chamber 21 having at least a substantially vertical central axis and preferably having an inner surface which is substantially circular in cross-section, i.e. the separation chamber is rotationally symmetrical with respect to its central axis. Connected to the separation chamber is a treatment air inlet 15 having a substantially annular cross-section perpendicular to the central axis. The separation chamber is further provided with a central pipe 17 for removing air and a landing foot 10 for recovering solids separated from air. Preferably, the down tube is concentric with the single-chamber cyclone separation chamber. Especially if the landing foot is short, it is advantageous to extend the lower part of the landing foot to reduce the internal vortex of the landing foot and not to lift the already separated solids from the bottom of the landing foot. The separation chamber 21 has a conduit 22 which allows the gas to be treated to be introduced into a flow along the inner surface of the separation chamber to separate the solid from the gas by centrifugal force.

The bottom portions of the landing legs 11,20 of cyclones 12, 13 each form their own collection tanks 23, 24.

* · *. The pipe constituting the landing foot 20 of the multi-hole cyclone may be a helical pipe, such as a conventional air-conditioning pipe. Preferably, the twist of this tube is parallel to the air flow of the single-aperture cyclone 12. The same applies to the multi-aperture cyclone impeller 22, viz

* I

*. “The wings are arranged in the same direction as the flow to the multi-aperture cyclone. In the case of Fig. 2 * · * *: * 'i, the inlet 14 of the single aperture cyclone is disposed on the side of the separator 11' • t i: 25 such that, from above, the air flow forms an anticlockwise vortex.

The multi-aperture cyclone guide blade 22 comprises a plurality of blades (in the case of Fig. 4; '.: 8 pieces) secured, e.g. by gluing or soldering, to two rings *'. _ 4> 30 23.24, whereby the air flow is led into the separation chamber radially between the rings.

Figure 3 shows an embodiment 42a, 42b of the embodiment of Figure 2, in which the multi-aperture cyclone 33 is disposed as a separate element on the top of the separator 42a 114382 between the single-aperture cyclone 32 and the filter 34. Reference numeral 35 denotes a single-aperture cyclone inlet, and reference numerals 36 and 37 refer to solids collection vessels. The separator base portion 42 has a separator base plate 39 and an upstream seal 38 for sealing the landing foot 43 against the base. The numbers 40 and 41 refer to the fan and the 5 electric motors and the outlet respectively.

The structure of the multi-hole cyclone 33 corresponds to the solution shown in Figure 4. Thus, it has blades 22 attached between two annular plates, whereby the air flow is radially directed to the cyclone.

The advantage of this embodiment is that virtually all solids are effectively removed from the air to be purified. At the same time, the filter cleaning interval becomes extremely long, since only the lightest solids particles can reach the filter.

Claims (14)

6, 114382 A method for removing solids from an air stream entering a central vacuum cleaner, comprising: separating a solid from a dusty stream of air in two steps, first introducing an air stream into a cyclone (12; 32) to separate the coarse solid, the use of a multi-gap cyclone (13; 33) as the second separating member. Method according to Claim 1, characterized in that the dusty air stream is introduced first into the single-aperture cyclone (12; 32) and then to the multi-aperture cyclone (13; 33). 15 Method according to Claim 2, characterized in that the lower legs (1 Ib, 20, 20a; 42b; 43) of the cyclones are each connected to its own collection tank (23,24; 36, 37). Method according to one of Claims 1 to 3, characterized in that the multi-aperture cyclone (13; 33) is disposed inside the separation chamber of the single-aperture cyclone (13; 32). The process according to claim 4, characterized in that the separation chamber of the single-aperture cyclone is cylindrical and the inlet (15) of the multi-aperture cyclone has an annular cross-section relative to the central axis of the arrangement. . Method according to claim 4 or 5, characterized in that a dusty ... air stream is introduced into the separation chamber of the single orifice cyclone (12) above the inlet (15) of the orifice cyclone (13). 30 *; A central vacuum cleaner dust separation arrangement comprising a suction hose and a fan: a sequential separation means comprising a first separation step consisting of a cyclone (12; 3 2) for separating coarse solids and a second separation means for finely divided 711438? for separating a solid, characterized in that the second separating member comprises a multi-aperture cyclone (13; 33). Dust separation arrangement according to Claim 7, characterized in that the 5-aperture cyclone (13) is disposed inside the separation chamber (11a) of the single-aperture cyclone (12). Dust separation arrangement according to Claim 8, characterized in that the separation chamber (11a) of the single orifice cyclone (12) is cylindrical and the inlet (15) of the orifice cyclone (13) has an annular cross-section with respect to the central axis of the arrangement. 10 Dust separation arrangement according to one of Claims 7 to 9, characterized in that the multi-aperture cyclone (13; 33) has a central tube (20,20a; 43) acting as a landing foot, which is concentric with the single-aperture cyclone (12) separation chamber (11a). Dust separation arrangement according to Claim 10, characterized in that the central tube (20) of the multi-aperture cyclone is expanded at its lower part (20a). Dust separation arrangement according to one of Claims 7 to 11, characterized in that the inlet (15) of the multi-aperture cyclone is connected to a separating impeller (22) which directs the air stream 20 to the wall of the separating chamber. . ' ; Dust separation arrangement according to claim 12, characterized in that the "*. Impeller blades (22) are followed by a single-hole cyclone to produce an airflow in the direction of the vortex. •»: ** '· 25 Dust separation arrangement according to one of Claims 7 to 13, characterized in that: * the multi-aperture cyclone outlet (22) is connected to the suction side of a central vacuum cleaner (18). »·» »» »• I • I * I t • · I 1 | t, 114382