vacuum pump

Abstract

Vacuum pump as part of a vacuum wastewater system for emptying and flushing toilets and urinals - with a collecting inlet line which is connected to an inlet (2) in a housing (1) of the vacuum pump and is closed inside the housing by a flap valve (12) when the vacuum pump is not in operation, - with a cutting device (4) which is axially arranged and which crushes solid substances in the wastewater, - with an axially arranged screw spindle (5) which, when rotated, forms a water ring (6) necessary for generating the vacuum and draws in the wastewater by means of vacuum, - with an outlet (7) and - with a drive motor (9) for the cutting device (4) and the screw spindle (5), characterized in that the inlet (2) is continued inside the housing (1) as a tubular channel (10) and the outlet opening (11) from the channel (10) can be closed by the flap valve (12), supported by gravity or part of the gravity of the flap (13) of the flap valve (12).

Description

[0001] The invention relates in particular to a vacuum pump, such as those used for emptying and flushing toilets or urinals, etc., in a vacuum wastewater system of ships, aircraft, and trains. The wastewater containing fecal matter is drawn in by the vacuum pump via collection lines, the solid components of the wastewater are macerated in the vacuum pump, and then the entire wastewater is conveyed to a collection tank. The vacuum pumps usually operate on the screw spindle principle.

[0002] Such a vacuum pump, arranged in a vacuum wastewater system with multiple wastewater sources, is known, among other places, from EP 0 454 794 B2 and WO 2012 / 115 521 A1.

[0003] Such vacuum wastewater systems operate discontinuously and are only activated when needed, i.e., the vacuum pump motor is only switched on when required. For the system to function and the vacuum pump to generate a vacuum, it is advisable, or even necessary, to maintain a vacuum within the system and to keep a certain volume of water in the vacuum pump. The latter is necessary to create the water ring required for vacuum generation in the area of ​​the screw spindle. If there is no or too little water in the vacuum pump, it must be refilled, which requires additional effort.

[0004] Therefore, valves are used that block the supply line to the vacuum pump and, if necessary, also the outlet from the vacuum pump when not in operation.

[0005] As can be seen from the cited EP 0 454 794 B2 and WO 2012 / 115 521 A1, the inlet line with inlet nozzle located at the top of the vacuum pump can be closed inside the housing by a flap valve, a rubber flap. When wastewater flows into the housing, this flap hangs down – thus not obstructing the flow – and is drawn in by the negative pressure in the inlet system when the vacuum pump is switched off, as the rubber flap then rests against the inlet nozzle, thus sealing it.

[0006] The KR 10 1 688 219 B1 describes a vacuum pump transfer device.The vacuum pump transfer device comprises: a housing with an inlet unit at the front, into which foreign materials flow, and an outlet unit at the rear, through which foreign materials are discharged to the outside; furthermore, a comminution unit, which is installed inside the housing and serves to comminute foreign materials introduced through the inlet; a suction unit, which is arranged at the rear of the comminution unit and draws the foreign materials introduced through the inlet unit into the comminution unit; a transfer unit, which is arranged at the rear of the suction unit and transfers the foreign materials drawn in by the suction unit; and a drive motor, which supplies rotational force to the comminution unit, the suction unit and the transfer unit by rotatably connecting a drive shaft element at the rear of the transfer unit and rotating the drive shaft element.

[0007] It has now been shown that, particularly after longer periods of inactivity, this cost-effective type of flap valve with a rubber flap is limited in its function, i.e., the necessary sealing of the inlet nozzle is no longer achieved, as the rubber flap bends downwards due to gravity and no longer rests against the inlet nozzle.

[0008] The object of the invention is to ensure a secure closure of the inlet port to the vacuum pump, even after extended periods of operation and downtime, while retaining a flap valve, thus eliminating the need for regular repairs and replacements of the rubber flaps. Simultaneously, sufficient water should always be present in the vacuum pump to ensure the necessary water ring for reliable start-up and rapid vacuum build-up without the need for refilling. This problem is solved with the features of claim 1; advantageous embodiments are the subject of the dependent claims.

[0009] A vacuum pump is used as part of a vacuum wastewater system for emptying and flushing toilets, urinals, etc. - with a collecting inlet line that is connected to an inlet in a housing of the vacuum pump and is closed inside the housing by a flap valve when the vacuum pump is not in operation, - with a cutting device that is axially arranged and shreds solid materials in the wastewater, - with an axially arranged screw spindle which, when rotated, forms a water ring necessary for generating a vacuum and draws in the wastewater through vacuum, - with an outlet and - with a drive motor for the cutting device and the screw spindle, it is proposed according to the invention that The inlet within the housing is continued as a tubular channel and the outlet opening from the channel can be closed by the flap valve, supported by gravity or part of the gravity of the flap of the flap valve.

[0010] If the inlet to the housing is from above, which is usual, the outlet opening from the channel is located lower down, with the outlet opening pointing upwards. This means that the channel is preferably routed around half the inner circumference of the housing on one or both sides.

[0011] The outlet opening from the channel is preferably arranged at a distance from the cutting device, with the distance (a) being between 70 and 110 mm. This distance ensures that the incoming wastewater is mixed in such a way that it can be processed by the cutting device without any problems.

[0012] It has proven effective to use a distributor, projecting beyond the cutting device towards the housing, on the axis of the cutting unit and the screw spindle to mix the solids in the wastewater. In a preferred embodiment, the distributor has a head in the shape of a square pyramid.

[0013] In a further advantageous embodiment, the flap and / or the edge of the outlet opening are provided with a seal. Since the channel and the housing are manufactured as a single casting, this measure also compensates for roughness resulting from the casting process.

[0014] The flap is preferably attached to the housing, in the area of ​​a viewing window, which ensures easy access to this attachment point. Attaching it to an inclined inner surface of the housing optimizes the effect of gravity during closure and minimizes obstruction of the wastewater flow into the housing.

[0015] The flap preferably has an angle of inclination α relative to the axis of the cutting device and the screw spindle, with this angle α being in the range of 20° to 60°. The inclined inner housing surface for mounting also has this angle of inclination α.

[0016] An embodiment of the vacuum pump according to the invention, as used in vacuum wastewater systems for emptying toilets on ships, is shown in the figure. In this embodiment, axis 3 is horizontal. The inlet and outlet are from and to the top, respectively.

[0017] The vacuum pump shown is divided into three sections: - a housing 1 with the inlet 2 arranged at the top for the wastewater from one or more toilets etc., - the actual pump housing, in which a cutting device 4 and a screw spindle 5 are arranged on an axis 3, and which has the outlet 7 at the top and - a drive motor 9 that drives the axle 3, whereby a water ring 6 forms in the pump housing when the drive motor 9 is running, which is responsible for generating the vacuum.

[0018] In the state of the art, the inlet is designed as a nozzle that ends immediately after entering the housing and is to be closed by a flap that can only be controlled by the pressure conditions and the inherent tension of the flap (material) in the system.

[0019] In contrast, the inlet 2 continues as a tubular channel 10 in the housing 1, here over half the inner circumference of the housing 1, so that the outlet opening 11 is located approximately opposite the inlet 2 - at the bottom of the housing 1. The outlet opening 11 is not parallel to the axis 3, but at an angle α of 22°.

[0020] Furthermore, the outlet opening 11 from the channel 10 is located below the axis 3 of the cutting device 4 and the screw spindle 5, here with a lateral distance (a) to the cutting device 4 of approximately 90 mm, in order to achieve thorough mixing of the wastewater upstream of the cutting device 4. This mixing is supported by a distributor 15 arranged on the axis 3 of the cutting device 4 and the screw spindle 5, which projects beyond the cutting device 4 towards the housing 1. The distributor 15 has a head in the shape of a square pyramid.

[0021] If, as shown, a flap valve 12 with flap 13 is arranged above the outlet opening 11, the flap 13 closes the outlet opening 11 not only through the pressure conditions in the system, but also due to a portion of the flap's weight acting on it, and, if the water level in the housing 1 is sufficient, also due to water pressure, so that it is securely closed when not in use. Additionally, the flap 13 and / or the edge of the outlet opening 11 is provided with a seal 14.

[0022] The flap 13 is attached to the side of the outlet opening 11 on the housing 1, so that the attachment point is easily accessible when the viewing window 16 is removed.

[0023] Maintaining a water level in the vacuum pump not only maintains the vacuum but also keeps the sliding seals 8 of the shaft 3 in place, thus preventing dry running and therefore damage to the sliding devices 8.

[0024] The vacuum pump according to the invention thus ensures stable operation of the vacuum wastewater system. Furthermore, the vacuum pump is designed so that it can be integrated into existing wastewater systems without major modifications. Reference symbol list 1 housing for inlet 2 Inlet 3-axis 4 Cutting device 5 screw spindle 6 Water ring 7 Outlet 8 Sliding seal 9 Drive motor 10-channel 11 Exit opening 12 flap valve 13 flap 14 Seal 15 distributors 16 viewing windows

Claims

[1] Vacuum pump as part of a vacuum wastewater system for emptying and flushing toilets, urinals - with a collecting inlet line which is connected to an inlet (2) in a housing (1) of the vacuum pump and is closed inside the housing by a flap valve (12) when the vacuum pump is not in operation, - with a cutting device (4) which is axially arranged and which crushes solid substances in the wastewater, - with an axially arranged screw spindle (5) which, when rotated, forms a water ring (6) necessary for generating the vacuum and draws in the wastewater by means of vacuum, - with an outlet (7) and - with a drive motor (9) for the cutting device (4) and the screw spindle (5), characterized by, that the inlet (2) is continued inside the housing (1) as a tubular channel (10) and the outlet opening (11) from the channel (10) can be closed by the flap valve (12), supported by gravity or part of the gravity of the flap (13) of the flap valve (12). [2] Vacuum pump according to claim 1, characterized by , that the inlet (2) into the housing (1) is arranged from above and the outlet opening (11) from the channel (10) is located lower in the housing (1), with the outlet opening (11) pointing upwards. [3] Vacuum pump according to claim 1 or 2, characterized by , that the outlet opening (11) from the channel (10) is arranged at a distance from the cutting device (4), preferably with a distance (a) between 70 and 110 mm and in particular greater than 85 mm. [4] Vacuum pump according to any one of claims 1 to 3, characterized by , that the flap (13) and / or the edge of the outlet opening (11) are provided with a seal (14). [5] Vacuum pump according to any one of claims 1 to 4, characterized by , that the flap (13) is attached laterally and / or above the outlet opening (11) on the housing (1) on an axis (3) of the cutting device (4) and the screw spindle (5) inclined inner surface of the housing. [6] Vacuum pump according to claim 5, characterized by , that the flap has an angle of inclination (α) to the axis (3) of the cutting device (4) and the screw spindle (5), preferably in the range of 20° - 60°. [7] Vacuum pump according to any one of claims 1 to 6, characterized by , that the channel (10) and the housing (1) are manufactured as a single casting. [8] Vacuum pump according to any one of claims 1 to 7, characterized by , that the channel (10) is guided on one or both sides over half the inner circumference of the housing (1). [9] Vacuum pump according to claim 5 or 6, characterized by, that on the axis (3) of the cutting device (4) and the screw spindle (5), a distributor (15) projecting beyond the cutting device (4) in the direction of the housing (1) is arranged for mixing the solids in the wastewater. [10] Vacuum pump according to claim 9, characterized by , that the distributor (15) has a head in the shape of a square pyramid.

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