NL2001293C2 - Gas cleaner for at least partially separating entrained components from a contaminated gas stream. - Google Patents

Description

Gas cleaner for at least partially separating entrained components from a contaminated gas stream

The invention relates to a gas cleaner for at least partially separating entrained components from a contaminated gas stream, comprising: a supply channel for sucking in the contaminated gas stream to be separated; at least one separation space symmetrically connected on a proximal side to the supply channel in an axial direction for separating the contaminated gas stream; which is provided with a gas outlet for discharging a cleaned gas stream, and a component outlet located substantially in the axial of the separation space, for discharging separated components; a component collection space connecting to the component outlet of the at least one separation space, for collecting the separated components; and a pump connecting to the gas outlet for sucking in the contaminated gas through the separation space. With the components to be separated, solid parts, liquid particles and a combination of solid parts and liquid particles are understood in this context.

The separation of components from a gas stream has very diverse applications. The purification of gas streams is for example known from applications such as vacuum cleaners, flue gas cleaners and installations for air treatment. Separation of components such as dirt with a substantial size is relatively easy. Existing gas cleaners, and more particularly vacuum cleaners, often use a filter bag (vacuum cleaner bag) with the disadvantage, among other things, that this filter bag provides more resistance when it becomes filled. For example, a vacuum cleaner with a substantially full vacuum cleaner bag will have less suction power than the same vacuum cleaner with an empty vacuum cleaner bag.

To remedy this problem, filter bagless gas cleaners have been developed that use one or more tangential cyclones whereby the heavier fraction (for example the dirt in the case of a vacuum cleaner) is separated from the polluted air stream by rotation. Examples of such gas cleaners are EP 0 042 723 and GB 2 426 726. Gas cleaners, and more particularly vacuum cleaners, of this type are also available as such in the regular trade.

2

The present invention has for its object to increase the efficiency and / or effectiveness of the type of gas cleaners described in the preamble, and more in particular vacuum cleaners, for at least partially separating entrained components from a contaminated gas stream.

5

To this end, the invention provides a gas cleaner of the type mentioned in the preamble, characterized in that the supply channel connects multiple to the at least one separation space, and that the at least one circle-symmetrical separation space is provided on the inside with rotation means in the form of at least two curved 10 guides for rotating the gas stream in the separation space. The separation space for separating the contaminated gas stream is preferably provided with the gas discharge on the proximal side. The orientation of the curved guides, which will generally be of leaf-shaped design, is such that they change the flow direction in at least one direction to ultimately result in a substantially directional flow direction (relative to the separation space). The supply channel can thus connect axially or radially to the at least one separation space. By replacing the traditional tangential cyclone separation space of the existing gas cleaners with at least one non-tangential type separation space according to the present invention, vortexes are generated in the separation spaces with much better flow characteristics than in the traditional cyclones. The multiple connection of the supply channel to the separation space and the multiple curved guides result in a more symmetrical and therefore more stable flow profile in the separation space, which results in a more efficient separation.

25

The measures according to the present invention thus result in an increased separation level (i.e. a better separation of gas and components) and / or in a lower pressure drop than with the tangential cyclones as used in the gas cleaners (vacuum cleaners) according to the prior art. For example, it is possible to choose to keep the level of separation between the improved gas cleaner and the conventional gas cleaner the same, thereby providing the advantage that the pressure drop required for this purpose becomes less large when the proposed improvements are implemented. On the other hand, it is also possible to keep the level of pressure drop between the improved gas cleaner and the conventional gas cleaner, which has the advantage that the level of separation 3 increases when the proposed improvements are implemented. It is also possible to opt for a combination of reduced pressure drop and increasing separation level. Such a separation space such as part of the gas cleaner according to the present invention can also be referred to as a "multi-port non-tangential cyclone".

The existing tangential cyclone gas cleaners (in particular tangential cyclone vacuum cleaners) have a compartment connected to the component discharge ("underflow") to which the components are discharged due to gravity (1G). The separating action of a vortex in the separation space is many times greater than 1G, which means that the force to move the components from the separation space to the collection compartment is relatively low. A further increase in efficiency and / or effectiveness can be obtained by connecting the component collection space to the gas outlet for the cleaned gas stream. This creates a so-called "recycle flow". The result of this measure is that there is a (limited) reduction in pressure in the component collection space, as a result of which a (limited) gas flow will flow through the component outlet. The limited gas flow thus ensures that the components to be removed are discharged more easily from the separation space.

20

By generating a "recycle stream" in the multi-port non-tangential cyclone, the components in the gas cleaner according to the invention now become much easier to remove from the separation space. It also becomes possible to position the gas cleaner in such a way that the component collection space is located next to or even above the separation space. This can be advantageous with mobile multi-port non-tangential cyclone gas cleaners such as vacuum cleaners that can continue to function independently of their orientation. Although constructions of gas cleaners have already been described (inter alia in US 2004/0144070) in which a component collection space is located above the separation space, the components must also be discharged there by gravity to the component collection space.

The passage of the connection of the component collection space to the gas discharge for the cleaned gas stream is preferably smaller than the passage of the gas discharge for the cleaned gas stream. This measure is desirable to prevent such a large recycle stream from being worked up in such a way that components are returned to the supply channel connection on the proximal side of the separation space. Thus, components are prevented from being "pumped around" which would lead to a reduced efficiency and / or effectiveness of the gas cleaner 5. This return of components can furthermore be prevented by providing the passage of the connection of the component collection space to the gas discharge for the cleaned gas flow with a filter. This filter prevents components collected in the component collection area from disappearing again. A filter for this may have a shape as desired; for example a static filter and / or a cyclone filter.

The at least one connection of the component collection space to the gas discharge (a "recycle connection") does not necessarily have to be connected to the gas discharge of the separation space; this can also be (possibly partly) located in the separation room (this is also referred to as an "internal recycle"). The connection of the component collection space to the gas discharge does not have to lead into the component collection space, but it can also take place on an individual separation space. This means that the connection for the recycle stream then connects to or near the components (located on the distal side of the separation space (s)). This results in the same separation effect in the separation room; only the last part of the route of the transport of the components to the component collection space is then no longer supported by the recycle stream.

In yet another preferred embodiment the gas cleaner comprises a plurality of separation spaces placed parallel to each other. This allows the capacity of the gas cleaner to be increased. All this makes it possible to make the gas cleaner relatively small.

It is also advantageous if the supply channel connects to the at least one separation space through the intervention of a pre-separator. This pre-separator can herein comprise a filter and / or a pre-separator collection space. In practice, a compact and aesthetic construction becomes possible if the pre-separator is provided with a substantially cylindrical filter drum, which for example surrounds the separation spaces.

5

In a preferred variant, the pre-separator comprises a chamber in which the pre-separated contaminated air stream is set in rotation. By also providing the pre-separator with a cyclone separator, the fraction of larger components can be captured with a limited pressure drop.

The pre-separator can also be equipped with a filter. This filter is preferably in the form of a substantially cylindrical filter drum between the chamber in which the air to be separated is put into rotation and the supply of the cylindrical filter drum located at least one separation space. In order to store the larger components captured by the pre-separator, it is desirable that the pre-separator also be provided with a pre-separator collection space.

For further stabilization of the flow profile in the separation space, it is advantageous if a (usually likewise curved) stabilizing element is positioned as part of the rotation means between two adjacent curved guides. Again, this is a measure that leads to a further increase in the efficiency and / or effectiveness of the separation in the gas cleaner.

In order to be able to easily remove the captured components from the gas cleaner, it is desirable that the at least one separation space is releasably coupled to the component collection space. Due to the releasable coupling, the component collection space can be opened in a simple manner, so that the components caught in the component collection space can be removed.

25

For inspection of the operation of the gas cleaner, it is advantageous to manufacture at least a part of the at least one separation space from a transparent material, whether or not in combination with the measure, to provide the gas cleaner with an at least partially transparent jacket. A further more compact construction becomes possible by integrating the casing with at least one separation space.

In order to prevent the cleaned gas flowing out of the separation space from rotating unnecessarily, it is advantageous to provide the gas discharge located on the proximate side of the at least one separation space for the cleaned gas flow with a rotation limiting lenght. Such a vortex breaker or anti-swirl element increases the efficiency of the device even further, because the rotational speed is reduced and as a result the local pressure increases. The result is that the total pressure drop across the separation space decreases.

5

The separation space usually has a tapered shape over at least a part of its length. Preferably, the wall of such a separation space encloses an angle with the axial that is greater than 5 °. In other words, the half "cone angle" of the separation space is greater than 5 °. The G-force in the axial direction (and possibly also in the distal direction) gradually increases as a result of maintaining momentum in combination with the decreasing cross-section; this increases the efficiency of the separation.

Furthermore, it is advantageous and possible to design the separation space in such a compact manner that it has a tapered shape over at least a part of its length, the largest diameter of which is smaller than 100 mm. This largest diameter of the separation space is found at the position where the gas stream has just left the curved guides and is also referred to as the throat diameter. Even more preferably, this largest diameter is smaller than 75 mm, 60 mm or even smaller than 50 mm. All this leads to a further reduction of the total volume of the gas cleaner and a greater separation force G.

In order to further increase the separation level, at least one additional after-separator can be placed for the cleaned gas flow located on the proximal side of the at least one separation space for the cleaned gas flow. Such a post-separator can again be formed by a cyclone (or several parallel-placed cyclones) with a diameter that is at most as large as the diameter of the at least one separation space. On the other hand (whether or not in combination with a possible cyclone post-separator) it is also possible to use a mechanical filter, for example in the form of a bacteriological filter.

30

The present invention will be further elucidated with reference to the non-limitative exemplary embodiments shown in the following figures. Herein: figure 1 shows a perspective and partly cut-away view of a part of a gas cleaner according to the present invention; and Figure 2 is a perspective and partially cut-away view of a separation space (including internal recycle) of a gas cleaner according to the present invention.

Figure 1 shows a part of vacuum cleaner 1 with a tangential supply opening 2. The polluted air is sucked in through this tangential supply opening 2. The air drawn in is then rotated in a pre-separator 3, as a result of which heavier dirt particles fall down in a compartment 4 for coarse dirt. After it has been rotated in an annular cyclone chamber 5 of the pre-separator 3, the pre-cleaned air is passed through a cylindrical filter 6, which also forms part of the pre-separator 3. This will also further pre-clean the polluted air. Again, the collected (mainly larger) dirt particles will fall down into the compartment 4 for coarse dirt.

The air fed through the cylindrical filter 6 then enters a distribution chamber 7 from which the pre-cleaned air is sucked in through a number of multiple ports 8 of six separation spaces 9. Here, the air is sucked in substantially radially through the separation chambers 9. In the separation spaces 9 there are curved guide blades 10 which convert the radial flow direction of the air into an axial flow direction and then into a substantially tangential flow direction. It is noted that in another embodiment variant this can also be, for example, a (direct) conversion of an axial flow direction to a tangential flow direction.

As a result of this change in the direction of flow in the separating spaces 9 and subsequently the tapered inner walls 11 of the separating spaces 9, efficient vortexing occurs in the separating spaces 9. With which the main flow of the (purified) air is axially surrounded by a cores surrounded by the curved guide blades 10. 12 is discharged through gas outlets 13. The smaller dirt particles come out of the separation spaces 9 through dirt outlets 14 at the distal side of the separation spaces 9 to end up in a dirt compartment with finer particles. In order to support the removal of the finer dirt through the dirt drains 14, a (smaller) passage 16 is arranged between the dirt drains 14 and the suction side of the gas drains 13. Due to the presence of this passage 16, a limited air steam will pass through the dirt discharges 14 are generated so that the (finer) dirt can more easily be discharged from the 8 separation spaces 9 into the compartment 15. The pump with which the air is sucked through the vacuum cleaner 1 is not shown. This is coupled downstream of the connection 17 which surrounds the gas outlets 13 and the passage 16.

Figure 2 shows a cut-away view of a separation space 20 of a gas cleaner which shows a great similarity with the separation spaces 9 as shown in figure 1. Corresponding components are therefore designated with identical reference numerals. In the separation space 20 there are curved guide blades 10 which connect to the radially placed supply ports 8. The curved guide blades 10 ensure that the radial flow direction of the air is converted into an axial and then into a substantially tangential flow direction. The sucked-in air subsequently enters an inner side of the separating space 20 bounded by the tapered inner wall 11. The main flow of the (purified) air is discharged axially through a central channel 21 in the core 12 surrounded by the curved guide blades 10 to a core 12 here. otherwise not visible gas discharge.

The smaller dirt particles come out of the separation space 20 on the distal side of the separation space 20 through dirt discharge 14. To support the removal of the finer dirt through the dirt discharge 14, there is a smaller passage 22 (also referred to as an "internal" recycle ") arranged from the dirt outlet 14 to the inside of the separation space 20. This constituent deviates from the passage 16 shown in figure 1. Due to the presence of passage 22 arranged in this case individually for the separation space 20 (this as an alternative to the central passage 16) shown in figure 1, a limited air steam will be generated in the separation space 20, as a result of which the (finer) dirt will exit the dirt outlet 14 more easily. Optionally, a filter (not shown) can be placed on one end 23 of the passage 22 to prevent dirt that has already been captured from being returned to the separation space 9. The re-injection nozzle 24 shown in this figure with which the air from the passage 22 is returned again the air is introduced substantially axially into the separation space. By providing the re-injection nozzle 24 with a different geometry, the air from the passage 22 can, for example, also be returned substantially radially and / or tangentially to the separation space.

Claims (23)

A gas cleaner for at least partially separating entrained components from a contaminated gas stream, comprising: 5. a supply channel for sucking in the contaminated gas stream to be separated; at least one circle space symmetrically connected to the supply channel on a proximal side for separating the contaminated gas stream, which; 10. is provided with a gas discharge for discharging a cleaned gas stream, and - a component discharge located substantially in the axial of the separation space, for discharging separated components; 15. a component collection space connecting to the component outlet of the at least one separation space, for collecting the separated components; and a pump connecting to the gas outlet for sucking in the contaminated gas through the separation space, characterized in that the supply channel connects multiple to the at least one separation space, and that the at least one circular-symmetrical separation space is provided on the inside rotation means in the form of at least two curved guides for rotating the gas flow in the separation space. 2. Gas cleaner as claimed in claim 1, characterized in that the supply channel connects axially to the at least one separation space. 30 A gas cleaner according to claim 1, characterized in that the supply channel connects radially to the at least one separation space. A gas cleaner according to any one of the preceding claims, characterized in that the component collection space connects to the gas outlet for the cleaned gas flow. 5. Gas cleaner according to claim 4, characterized in that the passage of the connection of the component collection space to the gas discharge for the cleaned gas flow is smaller than the passage of the gas discharge for the cleaned gas flow. 6. Gas cleaner according to claim 4 or 5, characterized in that the passage of the connection of the component collection space to the gas discharge for the cleaned gas flow is provided with a filter. A gas cleaner according to any one of claims 1 to 3, characterized in that the gas discharge for the cleaned gas flow from an individual separation space connects to the component discharge from at least one separation space. 15 A gas cleaner according to any one of the preceding claims, characterized in that gas cleaner comprises a plurality of separation spaces arranged in parallel. 9. Gas cleaner as claimed in any of the foregoing claims, characterized in that the supply channel connects to the at least one separation space through the intervention of a pre-separator. 10. Gas cleaner as claimed in claim 9, characterized in that the pre-separator comprises a chamber in which the contaminated air stream to be separated is brought into rotation. Gas cleaner according to claim 9 or 10, characterized in that the pre-separator comprises a filter. A gas cleaner according to claim 11, characterized in that the filter is formed by a cylindrical filter drum which surrounds at least one separation space. A gas cleaner according to any one of claims 9-12, characterized in that the pre-separator comprises a pre-separator collection space. 14. Gas cleaner as claimed in any of the foregoing claims, characterized in that a stabilizing element is positioned as part of the rotation means between two adjacent curved guides. 15. A gas cleaner according to any one of the preceding claims, characterized in that the gas cleaner at least one separation space is releasably coupled to the component collection space. A gas cleaner according to any one of the preceding claims, characterized in that at least a part of the at least one separation space is made of a transparent material. 15 A gas cleaner according to any one of the preceding claims, characterized in that the gas cleaner is provided with an at least partially transparent jacket. 18. Gas cleaner as claimed in any of the foregoing claims, characterized in that the gas discharge for the cleaned gas flow located on the proximal side of the at least one separation space is provided with a rotation-limiting element. 19. Gas cleaner as claimed in any of the foregoing claims, characterized in that the separation space has at least a part of its length a tapered shape whose wall encloses an angle with the axial that is greater than 5 °. A gas cleaner according to any one of the preceding claims, characterized in that the separation space over at least a part of its length has a tapered shape, the largest diameter of which is less than 100 mm. 30 A gas cleaner according to any one of the preceding claims, characterized in that the separation space over at least a part of its length has a tapered shape, the largest diameter of which is smaller than 60 mm. A gas cleaner according to any one of the preceding claims, characterized in that at least one additional post-separator is disposed for the gas discharge located on the proximal side of the at least one separation space for the cleaned gas flow. 5 23. Gas cleaner as claimed in claim 22, characterized in that the additional after-separator is formed by a plurality of separating spaces arranged in parallel, and wherein the throat diameter of these parallel arranged separating spaces is smaller than the throat diameter of the upstream at least one circle symmetrical separating space.