Surface cleaning device

Abstract

Surface cleaning device with a suction unit (22) for generating a suction flow, and with a suction nozzle (14) in flow communication with the suction unit (22) for extracting a liquid-air mixture, and with a separating device (44) for separating liquid from the extracted liquid-air mixture, and with a liquid tank (42) for receiving the separated liquid, wherein the separating device (44) has an inlet channel (60) for the extracted liquid-air mixture, at least one flow deflection element (70) for deflecting the liquid-air mixture and an air outlet channel (62) for releasing the extracted air to the suction unit (22), wherein the separating device (44) has a separating unit (52) with an inner tube (54) and an outer tube (56) circumferentially surrounding the inner tube (54) forming an annular space (82),wherein the inlet channel (60) and the air outlet channel (66) are arranged in the inner tube (54) and the annular space (82) is arranged downstream of the at least one flow deflection element (70) with respect to the suction flow and forms a vortex chamber, and wherein the annular space (82) has at least one annular space inlet (92) and at least one annular space outlet (94, 96), wherein the at least one annular space outlet (94, 96) opens into the air outlet channel (62), characterized in that the annular space (82) has two annular space outlets (94, 96) arranged circumferentially offset from each other.

Description

[0001] The invention relates to a surface cleaning device with a suction unit for generating a suction flow, and with a suction nozzle in flow communication with the suction unit for extracting a liquid-air mixture, and with a separation device for separating liquid from the extracted liquid-air mixture, and with a liquid tank for receiving the separated liquid, wherein the separation device has an inlet channel for the extracted liquid-air mixture, at least one flow deflection element for deflecting the liquid-air mixture and an air outlet channel for releasing the extracted air to the suction unit.

[0002] With the help of such a surface cleaning device, a surface, such as a floor or tabletop, a tiled wall, or a glass surface, especially a window pane, can be cleaned. The surface cleaning device can be guided along the surface to be cleaned and has a suction nozzle that is connected to a suction unit. The suction unit generates a suction flow, under the effect of which a liquid-air mixture can be extracted from the surface to be cleaned or from a cleaning element of the surface cleaning device that is in contact with the surface. A cleaning roller, a cleaning pad, or a cleaning cloth can be used as a cleaning element, for example.

[0003] The suction unit typically comprises a suction turbine and an electric motor driving the turbine. To prevent liquid from entering the suction unit and being released into the environment, a separator is installed in the flow path between the suction nozzle and the suction unit. This separator is designed to remove the extracted liquid from the liquid-air mixture. The separated liquid is collected in a liquid tank, which can be emptied as needed.

[0004] To separate liquid from the extracted liquid-air mixture, EP 2 959 814 A1 proposes a separation device comprising an inlet channel and an air outlet channel aligned coaxially with it. The inlet channel is connected to the suction nozzle via an inlet line, and the air outlet channel is connected to the suction unit via an air outlet line. Two flow deflectors are arranged in the flow path between the inlet channel and the air outlet channel, each deflecting the extracted liquid-air mixture by at least 90°. The extracted air can readily follow this deflection, whereas at least a large proportion of the extracted liquid impacts the flow deflectors and is separated there.

[0005] A similarly designed separation device is known from EP 2 992 798 A1. In this separation device, the extracted liquid-air mixture is deflected by 90° at the outlet of the inlet channel by means of a first flow deflector, so that at least part of the extracted liquid separates at the first flow deflector. On the side facing away from the first flow deflector is the inlet of a second flow deflector, to which the air outlet channel is connected.

[0006] Publication CN 203991418 U discloses a separation device in which a total of three channels, essentially aligned with each other, are used, between which the extracted liquid-air mixture is deflected.

[0007] Publication DE 10 2008 004 964 B3 discloses a hard surface vacuuming device comprising a suction nozzle and a suction unit for extracting a liquid-air mixture from a hard surface, a separation device for separating liquid from the liquid-air mixture, and a liquid tank for collecting the separated liquid. The dirty liquid tank has a tank emptying opening that can be tightly sealed by means of a lid.

[0008] A surface cleaning device of this type is known from DE 20 2014 004 864 U1.

[0009] Surface cleaning devices of the type mentioned above are often moved by the user along the surface to be cleaned at a highly uneven speed, with the direction of movement of the device relative to the surface being cleaned changing abruptly. This makes effective liquid separation difficult, as there is a risk that already separated liquid droplets will be forced into the air outlet duct and sucked towards the suction unit due to inertial forces during abrupt changes in direction and speed of the device. This effect is further amplified if the user operates the surface cleaning device overhead, so that the suction nozzle is positioned below the separation device and the suction unit. The surface cleaning device can assume such a position, for example, when cleaning a window pane or a table surface.

[0010] The object of the present invention is therefore to further develop a surface cleaning device of the type mentioned at the outset in such a way that it ensures the separation of liquid from the extracted liquid-air mixture in a manner that is as independent of position as possible.

[0011] This problem is solved by a surface cleaning device with the features of claim 1.

[0012] The surface cleaning device according to the invention uses a separation device with a separation unit comprising an inner tube and an outer tube surrounding it. The inner tube accommodates the inlet channel and also the air outlet channel of the separation device.

[0013] The inlet channel can be separated from the air outlet channel within the inner tube by means of a partition.

[0014] In particular, it may be provided that the inlet duct is aligned parallel to the air outlet duct.

[0015] Under the influence of the suction unit, the extracted liquid-air mixture first flows through the inlet channel and then encounters at least one flow deflector. At least a portion of the extracted liquid separates at the at least one flow deflector.

[0016] Downstream of the at least one flow deflector, the separator unit has an annular space located between the inner and outer pipes. This annular space forms a vortex chamber, allowing the extracted air to create a vortex within it. This enhances the separation effect. From the annular space, the air flows into the air outlet duct located in the inner pipe. The extracted air then passes through this duct to the suction unit, from which it is discharged to the environment via at least one exhaust opening.

[0017] The annular space surrounding the inner tube has at least one annular space inlet arranged downstream of the at least one flow deflection element and two annular space outlets arranged circumferentially offset from each other, which open into the air outlet channel.

[0018] It has been shown that the surface cleaning device according to the invention can be operated in any position without any noticeable effect on the separation efficiency. The user can guide the surface cleaning device along the surface to be cleaned with abrupt changes in speed and direction, and it can also be operated upside down, so that the suction nozzle is positioned below the separation device and below the suction unit. Despite abrupt changes in speed and direction, the extracted liquid is reliably separated from the extracted air and collected in the liquid tank, thus ensuring, in particular, that the extracted air is not released into the environment via an exhaust vent located downstream of the suction unit.

[0019] The extracted liquid is often water, which may also contain a cleaning chemical. This can lead to foam formation in the separation direction, especially during abrupt changes in speed and direction of the surface cleaning device. However, it has been shown that such foam formation has only a negligible effect on the separation efficiency.

[0020] With respect to the longitudinal axis of the air outlet duct, the two annular outlets advantageously open radially into the air outlet duct. As already mentioned, an air vortex can form within the annular space, and from this vortex, the air can then flow radially into the air outlet duct.

[0021] It is advantageous if the two annular outlets are diametrically opposed to each other.

[0022] With respect to the longitudinal axis of the air outlet duct, in an advantageous embodiment of the invention, the annular space inlet opens axially into the annular space. In such an embodiment, the extracted air and any entrained liquid droplets, after being deflected by the at least one flow deflection element, can flow axially into the annular space. Within the annular space, entrained liquid droplets are reliably separated on the inside of the outlet pipe due to the formation of an air vortex, and the air can then flow from the annular space through the air outlet duct to the suction unit and from there to the environment via at least one exhaust opening.

[0023] It is advantageous if the annular space extends beyond the at least one annular outlet in the direction away from the annular inlet. For example, the annular space can extend practically over the entire length of the inner tube, and the at least one annular outlet is arranged approximately centrally in the annular space in the axial direction, so that fluid can separate in the axial direction both in the area between the annular inlet and the at least one annular outlet, and in the area between the at least one annular outlet and the end of the annular space away from the annular inlet.Particularly in overhead operation, where the suction nozzle is positioned below the suction unit and the separator, it is advantageous if the annular space extends beyond the at least one annular space outlet in the direction away from the annular space inlet, because in such a position of the surface cleaning device, separated liquid can collect in the area of ​​the annular space extending beyond the at least one annular space outlet without the risk of the separated liquid reaching the air outlet duct via the at least one annular space outlet.

[0024] In an advantageous embodiment of the invention, a flow deflection element is arranged at the downstream end of the inlet tank. In such an embodiment, the extracted liquid-air mixture, after flowing through the inlet channel, directly encounters a flow deflection element.

[0025] In a particularly advantageous embodiment of the invention, the flow deflection element arranged at the downstream end of the inlet channel is designed as a hollow body which forms a hollow body inlet line arranged in line with the inlet channel and at least one hollow body inlet line arranged at an angle to the hollow body inlet line.

[0026] It is advantageous if the hollow body forms two opposite hollow body outlet lines, through which a portion of the extracted liquid-air mixture is led out of the hollow body.

[0027] Preferably, the at least one hollow body outlet line is oriented perpendicular to the hollow body inlet line. In such a configuration, the extracted liquid-air mixture undergoes a flow deflection of 90° within the flow deflection element arranged at the downstream end of the inlet channel.

[0028] Advantageously, the flow deflection element arranged at the downstream end of the inlet channel is designed in the form of a T-piece, in which two hollow body outlet lines facing away from each other and each aligned perpendicular to the hollow body inlet line are connected to a hollow body inlet line arranged in line with the inlet channel.

[0029] In an advantageous embodiment of the invention, the outer tube is longer than the inner tube, with the at least one hollow outlet pipe extending through the outer tube in an end section projecting beyond the inner tube. In such an embodiment of the invention, the extracted liquid-air mixture undergoes a further flow deflection on its way from the flow deflection element to the annular space surrounding the inner tube, since the flow path from the at least one hollow outlet pipe leads around the end region of the outer tube, so that a further portion of the extracted liquid is separated and the extracted air can flow into the outer tube at the free end face and from there into the annular space.

[0030] In an advantageous embodiment of the invention, the flow cross-section of the outer tube decreases with increasing axial distance from the end of the inner tube. The end region of the outer tube that projects beyond the inner tube can, for example, be conical in shape. Due to the changing flow cross-section of the outer tube, the air experiences a change in its flow velocity, thereby enhancing the separation effect of the separator.

[0031] It is advantageous to have a protective hood at the free end of the outer pipe. The extracted air must flow around the protective hood on its way to the suction unit, so that further liquid separation occurs at the hood. In addition, the protective hood reduces the risk of separated liquid entering the outer pipe.

[0032] It may be provided that the separation device is arranged in a separation chamber that is structurally separate from the liquid tank, so that the separation of liquid from the extracted liquid-air mixture takes place within the separation chamber and the separated liquid can then flow from the separation chamber to the liquid tank.

[0033] In a preferred embodiment of the invention, the separation unit is immersed in the liquid tank. In such an embodiment, the separation of liquid from the extracted liquid-air mixture takes place directly in the liquid tank. For this purpose, the separation unit is immersed in the liquid tank; that is, both the inner and outer tubes are immersed in the liquid tank. The at least one flow deflector arranged downstream of the inlet channel can direct the extracted liquid-air mixture against the wall of the liquid tank, so that at least a portion of the extracted liquid is separated on the wall of the liquid tank.

[0034] Preferably, the separator unit extends at least to the middle of the liquid tank. If the surface cleaning device is operated in an upright position, that is, in a position where the suction nozzle is located above the liquid tank and the separator unit, separated liquid can collect inside the tank below the separator unit. If the surface cleaning device is operated upside down, the separated liquid can collect inside the tank in the area surrounding the separator unit. This minimizes the risk of separated liquid entering the separator unit if the surface cleaning device changes position.

[0035] In an advantageous embodiment of the invention, the separating device has a cover on which the separating unit is held, wherein the cover closes a tank opening of the liquid tank in a flow-tight manner and has an inlet opening leading into the inlet channel and an air outlet opening leading into the air outlet channel, wherein the inlet opening is in flow communication with the suction nozzle via a suction line, and wherein the air outlet opening is in flow communication with the suction unit via an air outlet line.

[0036] The cover can be designed in the form of a plug that tightly seals a tank opening of the liquid tank and has an inlet opening and an air outlet opening.

[0037] Conveniently, the cover at the tank opening is designed to be removable, so that the cover, along with the separator unit, can be separated from the liquid tank by the user if necessary.

[0038] The surface cleaning device according to the invention comprises a housing. In a particularly advantageous embodiment of the invention, the liquid tank, together with the separator, forms a detachably mounted assembly in the form of a liquid collection device, wherein a tank drain opening is arranged on the cover, to which a closing wall of the housing is assigned. The tank drain opening can be tightly sealed by the closing wall and is freely accessible by detaching the liquid collection device from the housing. In such an embodiment of the invention, the cover has a tank drain opening in addition to the inlet opening and the air outlet opening. When the liquid collection device is mounted, i.e., connected to the housing, the tank drain opening is tightly sealed by a closing wall of the housing assigned to it.When the liquid collection device is installed, no liquid can escape from the liquid tank via the tank drain opening. However, when the liquid collection device is detached from the housing, the housing's closing wall, which corresponds to the tank drain opening, releases the opening, allowing the liquid tank to be emptied without having to remove any additional sealing element. This makes handling the surface cleaning device very easy when emptying the liquid tank.

[0039] The tank emptying opening is conveniently located offset from the separator unit on the cover.

[0040] To seal the tank opening, the cover preferably has a sealing device, in particular an elastic molded seal.

[0041] The surface cleaning device according to the invention is advantageously designed as a handheld device that has a handle by which the user can grasp the surface cleaning device.

[0042] It is particularly advantageous if the surface cleaning device according to the invention is designed as a portable window cleaning device. For this purpose, at least one flexible squeegee lip can be arranged at a suction opening of the suction nozzle, so that the surface cleaning device can be moved along a window pane in the manner of a manual window squeegee and liquid accumulates in the area of ​​the suction opening under the action of the squeegee lip, which is then captured by the suction flow.

[0043] The following description of an advantageous embodiment of the invention, in conjunction with the drawing, serves for further explanation. The drawing shows: Fig. 1: A side view of a surface cleaning device with a suction nozzle and a liquid collection device, which are detachably held on a housing; Fig. 2: a sectional view of the surface cleaning device along line 2-2 in Fig. 1; Fig. 3: a side view of the surface cleaning device, with the liquid collection device removed from the housing; Fig. 4: a side view of the liquid collection device; Fig. 5: a perspective view of the liquid collection device in the style of an exploded view; Fig. 6: a side view of a separation device of the liquid collection device; Fig. 7: a sectional view of the separation device along line 7-7 in Fig. 6; Fig. 8: a sectional view of the separation device along line 8-8 in Fig. 7; Fig. 9: a sectional view of the separation device along line 9-9 in Fig. 6.

[0044] The drawing schematically illustrates an advantageous embodiment of a surface cleaning device according to the invention, which is designated by reference numeral 10. In the illustrated embodiment, the surface cleaning device 10 is designed as a hand-held hard surface cleaning device with which liquid can be extracted from a hard surface, for example, a window pane, a table surface, a tiled wall, or a shower cubicle.

[0045] The surface cleaning device 10 has a housing 12 to which a suction nozzle 14 and a liquid collection device 16 are detachably attached. The housing 12 forms a handle 18, which the user can grip with one hand to guide the surface cleaning device 10 along the surface to be cleaned. In the drawing, the surface cleaning device 10 is shown in an upright position, with one longitudinal axis 20 of the surface cleaning device 10 aligned vertically and the suction nozzle 14 positioned above the housing 12. However, the surface cleaning device 10 can be used by the user not only in the upright position but in any orientation; for example, the surface cleaning device 10 can be operated lying down, i.e., with its longitudinal axis 20 aligned horizontally, or even upside down.This makes it easier for the user to guide the surface cleaning device 10 along, for example, a window pane or a table surface.

[0046] Below the handle 18, a suction unit 22 is arranged in the housing 12. This unit comprises a suction turbine 24 and an electric motor 26 that drives the suction turbine 24. Adjacent to the electric motor 26, a rechargeable battery 28 and control electronics 30 are arranged in the housing 12. A manually operated switching element 32 is positioned at the end of the handle 18 opposite the suction unit 22 for switching the electric motor 26 on and off.

[0047] The suction nozzle 14 is detachably held on the housing 12 and has a first squeegee lip 34 and a second squeegee lip 36, which are positioned at a suction opening 38. A suction line 40 connects to the suction opening 38.

[0048] The liquid collection device 16 is also detachably held on the housing 12. It comprises a liquid tank 42 and a separating device 44. The liquid tank 42 and the separating device 44 together form an assembly that can be separated as a whole from the housing 12.

[0049] The liquid tank 42 has a tank opening 46, which is designed in the form of a nozzle. The separating device 44 has a cover 48 that covers the tank opening 46 and includes a molded seal 50 that extends into the tank opening 46 and seals it tightly.

[0050] A separator unit 52 is held on the cover 48 and is immersed in the liquid tank 42. The separator unit 52 has an inner tube 54 and an outer tube 56 that circumferentially surrounds the inner tube 54. The inner tube 54 is divided by an angled partition 58 into an inlet channel 60 and an air outlet channel 62. The inlet channel 60 and the air outlet channel 62 are aligned parallel to the longitudinal axis 20 of the surface cleaning device 10, that is, the longitudinal axis 67 of the air outlet channel runs parallel to the longitudinal axis 20 of the surface cleaning device 10. The inlet channel 60 is in flow communication with the suction line 40 via an inlet opening 64 of the cover 48, and the air outlet channel 62 is in flow communication with an air outlet line 68 via an air outlet opening 66, which passes through the handle 18 and extends to the suction unit 22.

[0051] At the downstream end of the inlet channel 60, away from the inlet opening 64, a T-shaped flow deflection element 70 is arranged in the form of a hollow body, which has a hollow body inlet line 72 aligned in line with the inlet channel 60 and two hollow body outlet lines 74, 76 facing away from each other and each aligned perpendicular to the hollow body inlet line 72.

[0052] The outer tube 56 is formed in two parts and comprises a first outer tube section 78 and a second outer tube section 80 adjoining it. The first outer tube section 78 surrounds the inner tube along its entire length, forming an annular space 82 that extends to the cover 48. The second outer tube section 80 connects to the end of the first outer tube section 78 facing away from the cover 48 and projects beyond the inner tube 54 with respect to the longitudinal axis 20 of the surface cleaning device 10, so that the outer tube 56 has a greater overall length than the inner tube 54.

[0053] With increasing distance from the first outer pipe section 78, the flow cross-section of the second outer pipe section 80 decreases. The second outer pipe section 80 is penetrated by the two hollow body outlet lines 74, 76 of the flow deflection element 70. This is particularly evident from Fig. 8 clearly.

[0054] The free end of the second outer tube section 80, facing away from the first outer tube section 78, forms an opening 84 which is partially covered by a protective hood 86. The protective hood 86, as can be seen in particular from the Fig. 6 and Fig. Figure 7 clearly shows a base 88 arranged at a distance from the opening 84 and partially covering the opening 84, and a jacket 90 which is integrally connected to the base 88 and extends circumferentially over an angular range of at least 180°, completely surrounding the opening 84 of the second outer tube section 80 on the side facing the housing 12. The protective cover 86 is held on the second outer tube section 80.

[0055] The annular space 82 surrounding the inner tube 54 circumferentially extends from the cover 48 to the free end of the first outer tube section 78 and forms an annular space inlet 92 at its end facing away from the cover 48, extending over the circumference of the inner tube 54. The air outlet duct 62 is closed at its end facing away from the cover 48, but it is in flow communication with the annular space 82 via two opposing annular space outlets 94, 96. This is particularly evident from Fig. 9 clearly.

[0056] In addition to the inlet opening 64 and the air outlet opening 66, the cover 48 has a tank drain opening 98, which is arranged offset from the separator unit 52 and is covered by a closing wall 100 of the housing 12 when the liquid collection device 16 is installed. A sealing device 102 is arranged on the closing wall 100. This is particularly evident from Fig.3 clearly. In the assembled state, in which the liquid collecting device 16 is held on the housing 12, the inlet opening 64, the air outlet opening 66 and the tank emptying opening 98 are in a liquid- and flow-tight manner against the sealing device 102.

[0057] As already mentioned, the liquid collection device 16 is detachably connected to the housing 12. For this purpose, the liquid tank 42 forms a support wall 104, which rests on a stepped retaining wall 106 of the housing 12. The retaining wall 106 is located at the level of the suction unit 22 and extends to a bottom wall 108 of the housing 12.

[0058] The cover 48 has a retaining clip 110, which in plan view is essentially C-shaped, with a first elastically deformable leg 112 and a second elastically deformable leg 114. A locking hook 116 or 118 is held at the free ends of each leg 112, 114, respectively. When the liquid collection device 16 is mounted, these locking hooks engage a complementary locking projection 120 or 122 of the housing 12. The locking hooks 116, 118, in combination with the locking projections 120, 122, form a locking connection that can be released by the user by pressing the two legs 112, 114 together to detach the liquid collection device 16 from the housing 12. The tank drain opening 98, which is covered by the closing wall 100 in the assembled state, is then freely accessible so that the liquid tank 42 can be emptied.

[0059] The surface cleaning device 10 can be started by the user by actuating the switching element 32. Under the action of the suction unit 22, a suction flow is formed, which extends from the suction opening 38 via the suction line 40, the inlet opening 64 and the inlet channel 60 through the flow deflector 70 into the liquid tank 42. From the liquid tank 42, the suction flow runs via the front opening 84 through the second outer pipe section 80 into the annular space 82 and from there via the two annular space outlets 94, 96 into the air outlet channel 62 and from there via the air outlet opening 66 and the air outlet line 68 to the suction unit 22. The air can be released to the environment via an exhaust opening 124 of the housing 12.The exhaust opening 124 is covered by the liquid tank 42 when the liquid collecting device 16 is mounted, but an air gap forms between the housing 12 and the liquid tank 42, through which the exhaust air can be released.

[0060] The surface cleaning device 10 can be used to vacuum liquid from a surface to be cleaned, for example, a window pane or a table surface. The user can guide the surface cleaning device 10 along the surface to be cleaned, using the squeegee lips 34, 36 to extract the liquid and direct it to the suction opening 38. In the area of ​​the suction opening 38, the liquid is captured by the suction flow of the suction unit 22, so that a mixture of liquid and air is fed to the separator 44 via the suction line 40. The extracted liquid-air mixture flows through the inlet channel 60 and the hollow body inlet line 72 connected to the inlet channel 60, and is then deflected by 90° and discharged into the liquid tank 42 via the two hollow body outlet lines 74, 76.A large portion of the liquid impacts the wall of the liquid tank 42 and separates there, whereas the air enters the second outer tube section 80 through the end-face opening 84 and flows from there essentially axially through the annular space inlet 92 into the annular space 82. An air vortex forms within the annular space 82, as the air can only escape radially through the two annular space outlets 94, 96 into the air outlet channel 62 and from there subsequently flows via the air outlet line 68 to the suction unit 22. The deflection of the extracted liquid-air mixture by means of the flow deflector 70 already results in a considerable separation of liquid. Further separation occurs as the air flows around the second outer tube section 80 and enters the second outer tube section 80 through the end-face opening 84.Within the annular space 82, which forms a vortex chamber in which the air is swirled, even the last liquid droplets are removed from the extracted air.

[0061] Liquid separation occurs regardless of the orientation of the surface cleaning device 10. In particular, liquid separation also occurs when the surface cleaning device 10 is in a horizontal or upside-down position. Any residual liquid that separates within the annular space 82 when the surface cleaning device 10 is operated upside down can be temporarily stored in the area of ​​the annular space 82 that extends between the annular space outlets 94, 96 and the cover 48. Therefore, even when operating upside down, there is practically no risk of liquid entering the air outlet duct 62 and from there reaching the suction unit 22.

[0062] During operation of the surface cleaning device 10, the separated liquid collects in the liquid tank 42. To empty this tank, simply release the locking connection between the liquid collection device 10 and the housing 12 by pressing together the two arms 112, 114, and remove the liquid collection device 16 from the housing 12. The liquid tank 42 can then be easily emptied via the tank drain opening 98 without having to remove a separate tank closure element, such as a plug, from the liquid tank 42.

[0063] The surface cleaning device 10 according to the invention is thus characterized by reliable, position-independent separation, without the risk of liquid being released into the environment via the exhaust opening 124. Furthermore, the surface cleaning device 10 according to the invention is characterized by its ease of use, with the liquid tank 42 being easily emptied.

Claims

[1] Surface cleaning device with a suction unit (22) for generating a suction flow, and with a suction nozzle (14) in flow communication with the suction unit (22) for extracting a liquid-air mixture, and with a separating device (44) for separating liquid from the extracted liquid-air mixture, and with a liquid tank (42) for receiving the separated liquid, wherein the separating device (44) has an inlet channel (60) for the extracted liquid-air mixture, at least one flow deflection element (70) for deflecting the liquid-air mixture and an air outlet channel (62) for releasing the extracted air to the suction unit (22), wherein the separating device (44) has a separating unit (52) with an inner tube (54) and an outer tube (56) circumferentially surrounding the inner tube (54) forming an annular space (82),wherein the inlet channel (60) and the air outlet channel (66) are arranged in the inner tube (54) and the annular space (82) is arranged downstream of the at least one flow deflection element (70) with respect to the suction flow and forms a swirl chamber, and wherein the annular space (82) has at least one annular space inlet (92) and at least one annular space outlet (94, 96), wherein the at least one annular space outlet (94, 96) opens into the air outlet channel (62), , characterized by , that the annular space (82) has two annular space outlets (94, 96) arranged circumferentially offset from each other. [2] Surface cleaning device according to claim 1, characterized by , that the two annular outlets (94, 96) open radially into the air outlet channel (62) with respect to the longitudinal axis (67) of the air outlet channel (62). [3] Surface cleaning device according to claim 1 or 2, characterized by, that the at least one annular space inlet (92) opens into the annular space (82) in an axial direction with respect to the longitudinal axis (67) of the air outlet duct (62). [4] Surface cleaning device according to claim 3, characterized by , that the annular space (82) extends in the direction away from the at least one annular space inlet (92) beyond the at least one annular space outlet (94, 96). [5] Surface cleaning device according to one of the preceding claims, characterized by , that a flow deflection element (70) is arranged at the downstream end of the inlet channel (60). [6] Surface cleaning device according to claim 5, characterized by , that the flow deflection element (70) is designed as a hollow body which forms a hollow body inlet line (72) aligned in line with the inlet channel (60) and at least one hollow body outlet line (74, 76) aligned at an angle to the hollow body inlet line (72). [7] Surface cleaning device according to claim 6, characterized by , that the hollow body forms two hollow body outlet lines (74, 76) facing away from each other. [8] Surface cleaning device according to claim 6 or 7, characterized by , that the at least one hollow body outlet line (74, 76) is aligned perpendicular to the hollow body inlet line (72). [9] Surface cleaning device according to claim 6, 7 or 8, characterized by , that the outer pipe (56) is longer than the inner pipe (54), wherein the at least one hollow body outlet pipe (74, 76) extends through the outer pipe (56) in an outer pipe section (80) that projects beyond the inner pipe (54). [10] Surface cleaning device according to claim 9, characterized by , that the flow cross-section of the outer tube (56) decreases with increasing axial distance from the end of the inner tube (54). [11] Surface cleaning device according to one of the preceding claims, characterized by , that a protective hood (86) is arranged at the free end of the outer tube (56). [12] Surface cleaning device according to one of the preceding claims, characterized by , that the separator unit (52) is immersed in the liquid tank (42). [13] Surface cleaning device according to claim 12, characterized by that the separation unit (52) extends at least to the middle of the liquid tank (42). [14] Surface cleaning device according to claim 12 or 13, characterized by, that the separating device (44) has a cover (48) on which the separating unit (52) is held, the cover (48) sealing a tank opening (46) of the liquid tank (42) in a flow-tight manner and having an inlet opening (64) opening into the inlet channel (60) and an air outlet opening (66) opening into the air outlet channel (62), the inlet opening (64) being in flow communication with the suction nozzle (14) via a suction line (40), and the air outlet opening (66) being in flow communication with the suction unit (22) via an air outlet line (68). [15] Surface cleaning device according to claim 14, characterized by, that the surface cleaning device (10) has a housing (12) and the liquid tank (42) in combination with the separating device (44) forms a liquid collection device (16) which is detachably held on the housing (12), wherein a tank emptying opening (98) is arranged on the cover (48) and a closing wall (100) of the housing (12) is associated with the tank emptying opening (98), wherein the tank emptying opening (98) can be tightly closed by the closing wall (100) and is freely accessible by detaching the liquid collection device (16) from the housing (12). [16] Surface cleaning device according to claim 15, characterized by , that the tank emptying opening (98) is arranged offset from the separating unit (52). [17] Surface cleaning device according to one of the preceding claims, characterized by , that the surface cleaning device (10) forms a portable window cleaning device.

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