EP3072430A1 - Device for vacuum cleaning with a vacuum cleaning device and filter bag - Google Patents

Abstract

The invention relates to a device for vacuuming with a vacuum cleaner and a filter bag, in which the vacuum cleaner has a motor-fan unit, which is designed such that the vacuum cleaner with inserted filter bag at aperture 0 according to EN 60312 a negative pressure between 30 kPa and 6 kPa, preferably generates a negative pressure between 20 kPa and 8 kPa, and more preferably a negative pressure between 15 kPa and 8 kPa, EN 60312 designating the standard in the version EN 60312: 1998 + A1: 2000 + A2: 2004, and at aperture 8 (40 mm) generates an air flow of between 25 l / s and 49 l / s, preferably an air flow of between 30 l / s and 45 l / s, and more preferably an air flow of between 35 l / s and 45 l / s, and the filter bag A disposable filter bag made of nonwoven fabric, which in the examination of the reduction of the maximum air flow with partially filled dust container analogous to EN 60312, a reduction in air flow of less than 15%, preferably who iger than 10%, more preferably of less than 5%.

Description

FIELD OF THE INVENTION

The invention relates to a device for vacuuming with a vacuum cleaner and a filter bag made of nonwoven fabric.

DEFINITIONS

The following standards, definitions and measurement methods are used to describe the state of the art and the invention:

EN 60312: EN 60312 refers to the standard in the version EN 60312: 1998 + A1: 2000 + A2: 2004.

EN 60335: EN 60335 refers to the standard in the version EN 60335-2-2: 2010.

Determination of the air data: The air data of a vacuum cleaner are determined in accordance with EN 60312 Section 2.8. The measuring device B is used in accordance with section 5.2.8. If motor-blower units are measured solo, ie without a vacuum cleaner housing, the measuring device B is also used.

The measurement of the reduction of the maximum air flow with partially filled dust container according to section 2.9 takes place at aperture 8 (40mm).

Nominal electrical power consumption of a vacuum cleaner: The power consumption of a vacuum cleaner is determined in accordance with EN 60335. According to EN 60335 and EN 60312, the input power is referred to as P ₁ . Nominal power consumption is the arithmetic mean of the maximum recording power and the minimum recording power according to EN 60335. The maximum power consumption at the highest air flow (open airflow) and the minimum power consumption at an air flow of 0 l / s (sealed suction) are measured. Electromotive driven attachments, such as brushes and the like, are not taken into account in the determination of the recording power.

Air flow: The air flow is determined according to EN 60312 with the measuring chamber according to version B. In the prior art, this air flow is often referred to as volume flow or suction air flow.

Air flow waste , constant air flow: The air flow waste is determined in the scope of suitability for use of vacuum cleaners in accordance with EN 60312 (section 2.9 of this standard) with the measuring chamber version B. Deviating from the standard, the decrease in air flow is checked by absorbing 400 g of DMT8 test dust in 50 g portions, provided that the maximum usable volume of the filter bag (see section 2.7 of this standard) is greater than 2 l. The three conditions that should lead to the termination of the test in accordance with section 2.9.1.3 of the standard are not taken into account. For volumes less than 2 liters, proceed as described in section 2.9.1.3. This method of measuring the airflow drop modified in this way in comparison with standard EN 60312 is referred to in the present specification and the patent claims as "analogous to EN 60312".

• q_max = maximaler Luftstrom bei leerem Staubbehälter
• q_c = maximaler Luftstrom bei teilgefülltem Staubbehälter

A constant air flow q is given if the air flow q _c after sucking up the DMT8 test dust is not lower than the air flow q _max with empty dust container (cyclone vacuum cleaner) or with empty filter bag (bag vacuum cleaner). Typically, 400 g of DMT8 test dust are absorbed in 50 g portions. The test is performed at aperture 8 (40 mm). Please refer to EN 60312, section 5.2.8.2 for the definition of the term diaphragm. This panel corresponds to a relatively open floor nozzle. The airflow drop is calculated according to: $$\mathrm{Airflow\; waste}\left[\%\right]=\left(\left({\mathrm{q}}_{\mathrm{Max}}-{\mathrm{q}}_{\mathrm{c}}\right)/{\mathrm{q}}_{\mathrm{Max}}\right)\times \mathrm{100}$$

• q _max = maximum air flow with empty dust container
• q _c = maximum air flow with partially filled dust container

With a substantially constant air flow is in the present description of the prior art and the invention, however, not meant that the air flow in different work situations, such as. As the sucking of carpet or hard floor or sucking with accessory nozzles, remains constant. Due to the different opening area of these nozzles and the different degrees of reduction of this opening area on different floor coverings, different air flows result depending on the work situation. In terms of EN 60312, this would correspond to a test with different apertures. Aperture 0 corresponds to the state with a clogged nozzle. Aperture 9 (50 mm) corresponds to an almost unhindered inflow. Common floor jets usually have an operating point in the range of aperture 7 (30 mm) to 8 (40 mm).

Increasing the power of the blower motor: The increase in power of the blower motor is understood to mean an increase in the power consumption [W]. In the case of a universal motor, the power setting takes place via a phase control. The SR motor (see below) regulates the control voltage of the motor.

SR motor: An SR motor is a switched reluctance motor characterized by a simple and robust design and high possible speeds (> 100,000 rpm). The torque is generated via the reluctance force.

Flat bags: Under a flat bag in the sense of the present invention filter bags are understood, the filter bag wall of two individual layers of filter material with the same surface is formed such that the two individual layers are interconnected only at their peripheral edges (the term same area does not exclude of course that the two individual layers differ from one another in that one of the layers has an inlet opening).

The connection of the individual layers can be realized by a weld or adhesive seam along the entire circumference of the two individual layers; but it can also be formed by a single layer of filter material is folded around one of its symmetry axes and the remaining open peripheral edges of the resulting two partial layers are welded or glued (so-called tubular bag). With such a production three welding or gluing seams are therefore necessary. Two of these seams then form the filter bag edge, the third seam can also form a filter bag edge or lie on the filter bag surface.

Flat bags in the sense of the present invention may also have so-called gussets. These gussets can be completely unfoldable. A flat bag with such gussets is for example in the DE 20 2005 000 917 U1 shown (see there Fig. 1 with folded gussets and Fig. 3 with unfolded gussets). Alternatively, the gussets may be welded to portions of the peripheral edge. Such a flat bag is in the DE 10 2008 006 769 A1 shown (see there in particular Fig. 1 ).

Surface folds: A filter bag whose filter bag wall has surface folds is known per se from the prior art, for example from the European patent application 10163463.2 (See there in particular Fig. 10a and Fig. 10b and Fig. 11a and Fig. 11 b). If the filter bag wall comprises several surface folds, then this material is also referred to as a pleated filter material. Such pleated filter bag walls are in the European patent application 10002964.4 shown.

Fig. 1 and Fig. 2 show a filter bag in cross-section with a wall, each having two surface folds. By such surface wrinkles, the filter surface of the filter bag is increased, resulting in a higher dust holding capacity of the filter bag with higher separation efficiency and longer life results (each opposite a filter bag with the same outer dimensions and no surface wrinkles).

In Fig. 1 is a filter bag 1 with a filter bag wall 10, which has two surface folds 11 in the form of so-called dovetails shown. The filter bag is shown here in cross section through the filter bag center. The longitudinal axes of the surface wrinkles thus run in a plane which in turn is perpendicular to the plane of the drawing, and the surface wrinkles go at their longitudinal ends in the plane parallel to the drawing plane and lying before and behind the plane of the weld seams of the filter bag. Thus, the surface wrinkles can develop most in their midst. The filter bag is shown here in a state in which the surface wrinkles are already unfolded somewhat.

In Fig. 2 is a filter bag 2 with a filter bag wall 20, which has two surface folds 21 in the form of so-called triangular folds shown. The filter bag is shown here in cross section through the filter bag center. The longitudinal axes of the surface wrinkles thus run in a plane which in turn is perpendicular to the plane of the drawing, and the surface wrinkles go at their longitudinal ends in the plane parallel to the drawing plane and lying before and behind the plane of the weld seams of the filter bag. Thus, the surface wrinkles can develop most in their midst. The filter bag is also shown here in a state in which the surface wrinkles are already unfolded.

In addition to the in Fig. 1 and Fig. 2 surface wrinkles are also possible surface wrinkles with other shapes. That the surface folds in the versions after Fig. 1 and Fig. 2 The surface folds are perpendicular to a bag edge is not to be understood as a limitation. Of course, the surface wrinkles may also be at an angle to the edges of the bag.

Suction power: Suction power is the product of negative pressure [kPa] and air flow [I / s]. According to EN 60312, the suction power is referred to as P ₂ .

Efficiency: The efficiency of a vacuum cleaner or a motor-blower unit is determined according to EN 60312 section 2.8.3.

STATE OF THE ART

The demands placed on devices for vacuuming have undergone a significant change in recent years.

The study by the "AEA Energy & Environment Group" commissioned by the "European Commission Energy" for the definition of the requirements for an eco-design for vacuum cleaners shows that it would be desirable in the future from an energy policy point of view, to limit the input power below 1100 W. should. However, vacuum cleaners users will expect the cleaning performance of vacuum cleaners, as available today with significantly higher pick-up power, to be substantially inferior.

The customer requirements for the hygiene of a device for vacuuming refer not only to the lowest possible dust emissions of the devices but also to the hygienic disposal of sucked dust.

With regard to the separation concept, vacuum cleaners without filter bags and vacuum cleaners with filter bags can be distinguished. These devices each have typical advantages and disadvantages.

Vacuum cleaners with filter bags are characterized by a high airflow. As the loading of the filter bag increases, however, the airflow decreases more or less. Until about the year 2000 filter bags made of paper were used in the first place. Such paper filter bags show a reduction in the maximum air flow with partially filled dust container analogous to EN 60312 an air flow drop of about 80% (or 60% when using a Innentissues). Thereafter, filter bags began to slowly enforce with nonwoven layers. First, filter bags were used with fleece layers of low dust storage capacity (SMS filter bag). By introducing filter bags Nonwovens with a capacity position, this decrease in air flow could be significantly reduced (see EP 0 960 645 ). Such filter bags show when checking the reduction of the maximum air flow with partially filled dust container analogous to EN 60312 an airflow drop of about 30%. Further improvements have been made by prefiltering loose fibers in the bag ( DE 10 2007 060 747 . DE 20 2007 010 692 and WO 2005/060807 ) or a pre-separation through a bag in the bag ( WO 2010/000453 . DE 20 2009 002 970 U1 and DE 20 2006 016 303 U1 ) reached. Flow deflections or flow distributions in the filter bag are in the EP 1 915 938 . DE 20 2008 016 300 . DE 20 2008 007 717 U1 (Dust-storing insert), DE 20 2006 019 108 U1 . DE 20 2006 016 304 U1 . EP 1 787 560 and EP 1 804 635 proposed. With such filter bags can be achieved by testing the reduction of the maximum air flow at partially filled dust container analogous to EN 60312 an airflow drop of about 15%. As a result, a further improvement in the Saugleistungskonstanz is achieved. The European patent applications 10002964.4 . 10163463.2 , and 10163462.2 disclose improved dust holding capability by pleating the filter material or by providing the filter bag with so-called surface wrinkles. The European patent application 10009351.7 shows how an optimized positioning of the bag in the vacuum cleaner improves the suction capacity. For example, such filter bags show an airflow drop of approximately 5% when testing the reduction of the maximum air flow in the case of partially filled dust containers in analogy to EN 60312.

With regard to the hygienic disposal of the sucked up dust holding plates have been developed, with which the filter bag is sealed manually, semi-automatically or automatically before removal from the vacuum cleaner (eg. EP 2 012 640 ).

Bagless vacuum cleaners - in particular cyclone vacuum cleaners - are distinguished by the fact that the air flow remains substantially constant when the dust collecting container is loaded with dust. The constant air flow of a cyclone vacuum cleaner is at first glance an advantage compared to vacuum cleaners with filter bags, which clog more or less with increasing loading of the filter bag, whereby the air flow is reduced accordingly. However, this is paid for by a very high nominal electrical power consumption of the cyclonic vacuum cleaner. This high energy input is required because of the high losses that the separation principle entails, namely the loss of maintaining the high velocity of rotation of the dust-laden air in the cyclone separator.

By combining several cyclone separators into multi-stage cyclones, an attempt was made to increase the efficiency and the separation efficiency ( EP 0 042 723 ). With such devices for vacuuming, an air flow of 33 l / s can be achieved. However, this is offset by a nominal electrical power of more than 2000W. With cyclone vacuum cleaner with an electrical power of approx. 1400 W an air flow of approx. 25 l / s can be realized.

With conventional devices for vacuuming with filter bags, an air flow of about 40 l / s can be realized today with newly inserted and unfilled filter bags. Such vacuum cleaners have a nominal input power of about 1300 W.

However, when filling with dust, the air flow decreases sharply, as in Fig. 3 you can see. Fig. 3 shows the reduction of the air flow as a function of the sucked amount of DMT 8 dust analogous to EN 60312 in known devices with filter bags (for example Miele S5210 with a nominal electrical power of 2200 W and various filter bags made of nonwoven fabric) and without filter bag (Dyson DC23 alergy with a nominal electrical power of 1400 W).

In addition to the improvements on the filter bags, there are some approaches in vacuum cleaners with filter bags by an electronic control to realize a constant air flow.

That's how it shows US 4,021,879 a device for vacuuming, the vacuum cleaner device has a control device by which the vacuum cleaner is controlled so that a substantially constant air flow is realized. In this device, however, filter bags made of paper are used. Due to the high tendency of filter bags to become clogged with paper (approx. 80% air flow waste with 400 g DMT8; US 4,021,879 not yet used), however, a very large control range for the nominal electrical power consumption must be provided. Although theoretically a constant air flow can be realized, this is very low. For this reason, this concept was no longer pursued and thus could not be translated into a successful product in the market.

DESCRIPTION OF THE INVENTION

In view of the aforementioned disadvantages of the prior art, the present invention seeks to provide a device for vacuuming with a vacuum cleaner and filter bags, in which the nominal electrical power consumption is significantly reduced, with the cleaning performance compared to devices for vacuuming, as they are today significantly higher recording power are available, may not deteriorate significantly.

This object is achieved by a device for vacuuming with the features of claim 1, that is by a device for vacuuming with a vacuum cleaner and a filter bag, in which the vacuum cleaner has a motor-fan unit, which is designed such that the vacuum cleaner with inserted filter bag At Aperture 0 a negative pressure between 30 kPa and 6 kPa, preferably a negative pressure between 20 kPa and 8 kPa, and particularly preferably a negative pressure between 15 kPa and 8 kPa, produced, and at Aperture 8 (40 mm) an air flow between 25 l / s and 49 l / s, preferably produces an air flow of between 30 l / s and 45 l / s, and more preferably an air flow of between 35 l / s and 45 l / s, and in which the filter bag is a disposable nonwoven filter bag When testing the reduction of the maximum air flow with partially filled dust container in accordance with EN 60312 a reduction of the air flow of less than 15%, vorzugswei less than 10%, more preferably less than 5%.

This particular characteristic of the motor-blower unit differs from the characteristic conventionally found in apparatuses for vacuum-cleaning motor-blower units in that the latter produce a much higher vacuum and a much lower maximum airflow.

Surprisingly, it has been found that such motor-blower units are particularly energy-efficient in use, and together with the disposable filter bags made of non-woven fabric, which reduces the air flow, i. an airflow drop of less than 15%, are comparable in their cleaning performance with vacuuming devices available today with significantly higher input power.

According to a particularly preferred development of the inventions described above, the vacuum cleaner device at aperture 8 (40 mm) can have an air output of more than 250 W, preferably more than 300 W, particularly preferably more than 350 W. sets If the invention is so, a fully satisfactory suction operation can be ensured via the complete filling of the filter bag.

The inventions described above can be further developed such that the vacuum cleaner device has a nominal electrical input power of less than 1200 W, preferably less than 1100 W, particularly preferably less than 900 W. Such recording services fully meet the future energy policy requirements.

Preferably, the motor-blower unit at aperture 8 (40 mm) has an efficiency according to EN 60335 of at least 20%, preferably of at least 25% and particularly preferably of at least 30%. This development of the invention leads to particularly energy-saving devices for vacuuming.

According to a preferred development of all inventions discussed above, the device may have a control device that controls the vacuum cleaner device so that the air flow at a loading of the filter bag with DMT8 test dust analogous to EN 60312 substantially constant at a value of at least 34 l / s, preferably is kept substantially constant at a value of at least 37 l / s, more preferably substantially constant to a value of at least 40 l / s.

An essential point expected of users of vacuuming devices, namely that the vacuuming device produces a constant air flow even with increasing dust loading, or in other words that the vacuuming device does not show any airflow drop with increasing dust load, can according to this preferred training can be realized.

This development is based on the concept that a device for vacuuming with filter bag is operated with an empty filter bag with a recording power that is set lower than the maximum power of the engine, so that the power consumption of the motor can be increased corresponding to the increasing loading of the filter bag. It has surprisingly been found that with filter bags having a tendency to clog of less than 15%, preferably less than 10%, more preferably less than 5%, only a relatively small increase in the intake power of the engine is required to the air flow on a for efficient vacuuming, ie at least 34 l / s, to be kept constant. Thus, a device for vacuuming could be realized, the one with substantial loading of the filter bag substantially Constant flow rate can be provided while maintaining the maximum electrical input power of the vacuum cleaner under a predetermined - from the viewpoint of power consumption acceptable - value of 1200 W.

According to a development of the invention described in the last three paragraphs, the device for vacuuming comprises an electronic control device, which is designed such that it regulates the electrical power consumption of the motor-blower unit.

The device is then preferably designed such that the increase in power consumption of the motor-blower unit necessary for maintaining the substantially constant air flow when loading the filter bag with DMT8 dust in analogy with EN 60312 does not exceed 35%, preferably not more than 20%. and more preferably not more than 15%, based on the power consumption of the motor-blower unit with empty filter bag is. According to this embodiment, devices for vacuuming can be realized with a constant air flow with a suction behavior, as it is known from today's non-adjustable devices, the future energy policy requirements can be easily met.

Particularly suitable for such a device is a motor-blower unit which has a reluctance motor, preferably a switched reluctance motor. Such motors are characterized in particular by the fact that they are robust and durable.

Alternatively, according to another preferred embodiment of the invention, a device may be provided, in which the control device has a throttle valve, which regulates the air flow so that it is substantially constant.

As controlled variables, the negative pressure downstream of the filter bag, the negative pressure upstream of the filter bag or the flow velocity measured at any desired point in the flow path can be used as a controlled variable in the two alternative refinements of the control device. Also possible are any combinations of these three sizes.

According to a preferred development of all inventions described above, the filter bag can be provided in the form of a flat bag. The flat bag form is the most common form for nonwoven bags since bags of this shape are very easy to manufacture. Because in contrast to the paper filter material used in filter bags made of paper, nonwoven filter material is very difficult because of the high resilience permanently fold, so that the production of more complex bag shapes, such as from block bottom bags or other bottom bag forms, is very complicated and expensive.

Particularly suitable for use in the device according to the invention are vacuum cleaner bags with pleated filter material or with surface wrinkles. Such vacuum cleaner bags are characterized by a particularly low air flow waste.

According to another embodiment of all the inventions described above, the vacuum cleaner device may have a filter bag change indication, which indicates when during the suction operation, the air flow for a predetermined time falls below the substantially constant value. In particular, the sensors that are already provided for the measurement of the controlled variables can be used for this purpose.

According to another preferred development of the inventions described above, the filter bag has a volume measured in accordance with EN 60312 in a range from 1.5 l to 8 l. Such filter bags are used primarily in vacuum cleaners, which are designed as a vacuum cleaner, as a hand vacuum cleaner, as Kesselsauger or Upright for household use.

BRIEF DESCRIPTION OF THE FIGURES

Fig. 1

und

Fig. 2:

Filterbeutel gemäß dem Stand der Technik mit Oberflächenfalten;

Fig. 3:

die Reduzierung des Luftstroms für Vorrichtungen zum Staubsaugen mit Staubsaugergeräten und Filterbeuteln gemäß dem Stand der Technik und für eine Vorrichtung zum Staubsaugen ohne Filterbeutel gemäß dem Stand der Technik;

Fig. 4:

die Luft-Kenndaten für eine Motor-Gebläseeinheit, die gemäß dem Stand der Technik in Vorrichtungen zum Staubsaugen eingesetzt wird;

Fig. 5:

die Luft-Kenndaten für eine Motor-Gebläseeinheit, die gemäß dem Stand der Technik nicht in Vorrichtungen zum Staubsaugen eingesetzt wird und sich besonders zur Implementierung der vorliegenden Erfindung eignet; und

Fig. 6:

Luftstrom und elektrische Aufnahmeleistung einer ersten und einer zweiten Ausführungsform der vorliegenden Erfindung.

The figures serve to explain the state of the art and the invention. Show it:

Fig. 1

and

Fig. 2:

Filter bag according to the prior art with surface wrinkles;

3:

the reduction of the air flow for devices for vacuuming with vacuum cleaners and filter bags according to the prior art and for a device for vacuuming without filter bag according to the prior art;

4:

the air characteristics for a motor-blower unit, which is used according to the prior art in devices for vacuuming;

Fig. 5:

the air characteristics for a motor-blower unit, which is not used in the devices for vacuuming according to the prior art and is particularly suitable for implementing the present invention; and

Fig. 6:

Air flow and electrical power of a first and a second embodiment of the present invention.

EMBODIMENTS OF THE INVENTION

In Fig. 5 the characteristic of the motor-blower unit according to an embodiment of the invention is shown. This is characterized by comparatively low maximum negative pressure at aperture 0 and a high volume flow at aperture 9 (50 mm). In particular, a negative pressure of 14.3 kPa is achieved at aperture 0. Aperture 9 (50 mm) results in an air flow of 86.5 dm ³ / s. The characteristic is therefore very flat. At maximum air flow, the engine consumes 1240 W of power. The air output (product of negative pressure and air flow) is a maximum of 498 W at aperture 7 (30 mm).

Fig. 4 shows the characteristic data for a motor-blower unit as used in the prior art in devices for vacuuming. At aperture 0, the motor-blower unit reaches a negative pressure of 35.8 kPa, at aperture 9 (50 mm) results in an air flow of 53.5 dm ³ / s. The fan characteristic is therefore very steep. At maximum air flow, the engine consumes 1900 W of power. The air output reaches 614 W. For highly clogging filter bags made of paper, such a design was also necessary and useful.

In the most preferred embodiment of the present invention, surface-folded filter bags are used as described in the DEFINITIONS section above.

With the in Fig. 5 shown motor-blower unit can be realized in combination with a filter bag with surface wrinkles and adapted to the filter bag space with a corresponding automatic control of the air flow, a vacuum cleaner, which achieves a high constant air flow at a power input of less than 1000 W. Fig. 6 shows the results for two embodiments according to the present invention. Both have in common that a very high constant air flow is achieved with low electrical input power.

Claims (15)

Device for vacuuming with a vacuum cleaner and a filter bag, in which
the vacuum cleaner device has a motor-blower unit, which is designed such that the vacuum cleaner device with inserted filter bag at orifice 0 according to EN 60312, a negative pressure between 30 kPa and 6 kPa, preferably a negative pressure between 20 kPa and 8 kPa and more preferably a negative pressure between 15 kPa and 8 kPa, where EN 60312 is the standard in the version EN 60312: 1998 + A1: 2000 + A2: 2004, the motor-blower unit is further designed such that the vacuum cleaner with inserted filter bag At aperture 8 (40 mm) according to EN 60312 an air flow between 25 l / s and 49 l / s, preferably an air flow between 30 l / s and 45 l / s, and particularly preferably an air flow between 35 l / s and 45 l / s generated, and the filter bag is a non-woven disposable filter bag having a reduction in air flow of less than 15%, preferably less than 10%, most preferably less than 5%, in the test of reducing the maximum air flow with partially filled dust container in analogy to EN 60312. Device according to claim 1, in which the vacuum cleaner device at aperture 8 (40 mm) has an air output of more than 250 W, preferably of more than 300 W, particularly preferably of more than 350 W. Device according to claim 1 or 2, in which the vacuum cleaner has a nominal electrical power of less than 1200 W, preferably less than 1100 W, more preferably less than 900 W. Device according to one of the preceding claims, in which the motor-blower unit at aperture 8 (40 mm) has an efficiency according to EN 60335 of has at least 20%, preferably of at least 25% and more preferably of more than 30%. Device according to one of the preceding claims, in which a control device is provided which controls the vacuum cleaner device so that the air flow at a loading of the filter bag with DMT8 test dust analogous to EN 60312 substantially constant at a value of at least 34 l / s, preferably in the is kept substantially constant at a value of at least 37 l / s, more preferably substantially constant to a value of at least 40 l / s. Device according to claim 5, in which the control device is an electronic control device which is provided such that it regulates the electrical power consumption of the motor-blower unit. Device according to claim 6, in which the increase in the power consumption of the motor-blower unit necessary to maintain the substantially constant air flow when loading the filter bag with DMT8 dust analogous to EN 60312 is not more than 35%, preferably not more than 20% and particularly preferred not more than 15%, based on the power consumption of the blower motor when the filter bag is empty. Device according to one of the preceding claims, in which the motor-blower unit comprises a reluctance motor, preferably a switched reluctance motor. Apparatus according to claim 5, in which the control means comprises a throttle valve provided to regulate the flow of air. Device according to one of the claims 5 to 9, in which the control device is designed such that the negative pressure downstream of the filter bag of the vacuum cleaner device and / or the negative pressure in front of the filter bag of the vacuum cleaner device is used as a controlled variable. Device according to one of the claims 5 to 10, in which the control device is provided such that the measured at any point in the flow path flow rate is used as a controlled variable. Device according to one of the preceding claims, in which the filter bag is designed as a flat bag. Device according to one of the preceding claims, in which the filter bag has surface folds. Apparatus according to any one of claims 5 to 13, in which the vacuum cleaner has a filter bag change indicator which indicates when, during the suction operation, the air flow falls below the substantially constant value for a predetermined time. Device according to one of the preceding claims, in which the filter bag has a volume measured according to EN 60312 in the range of 1.5 l to 8 l.

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