DE102006048812A1 - Wet suction device i.e. sucker, for sucking e.g. swarf, has device for monitoring liquid level in intake container, and including sensor that is designed as temperature sensor and arranged in area of preset maximum level height - Google Patents

Abstract

The device (1) has an intake container (6) receiving a liquid (3) and a device (100) for monitoring a liquid level (101) in container. The device has a control- and evaluation unit (16) that causes disconnection of a suction device (5) and/or activates a display device, if the liquid reaches a preset maximum level height, and a sensor arranged in an area of the height. The sensor is designed as a temperature sensor (13) e.g. thermoresistive sensor, negative temperature coefficient- or positive temperature coefficient-thermistor, and arranged in a housing made of plastic and stainless steel.

Description

The Innovation relates to a wet vacuum, especially for Solids containing liquids, after the features of the preamble of claim 1.

From the EP-A-0 456 084 a liquid aspirator is known which comprises a suction device, a liquid receiving receptacle and a device for monitoring the liquid level in the receptacle. In this case, the device for monitoring the liquid level contains a sensor arranged in the region of the maximum fill level and a control and evaluation device arranged outside the receptacle and connected to at least one sensor, which activates a display device when the liquid has reached the maximum fill level. As a sensor for level switching is used in this known sucker a light barrier.

When A disadvantage is the use of photoelectric sensors for level switching however, proved that the Light source and the reflector especially when sucking strong contaminated liquids easily contaminated and the corresponding components are cleaned regularly have to.

From the DE-A-38 03 826 Furthermore, a wet vacuum is known in which a level shutdown is done by means of a table tennis ball-shaped float. This float acts as a valve body and closes upon reaching the predetermined liquid level, the suction opening of the receptacle. The then abruptly occurring in the suction line vacuum increase is used to actuate a pressure switch, which interrupts the power supply of the suction device.

adversely is in this known Naßsauger, that the Swimmer due to contamination or adhesion of particles in his guideway is blocked and liquid then get into the suction device. In addition, the float is added foaming Media often not raised, because the density of the foam significantly below that of the liquid lies. The float therefore does not float on strong foam formation, and the foam is sucked into the suction device.

Of the Innovation is the object of a Naßsauger of the type mentioned indicate which sensor has a liquid level monitor contains which always generates a signal when the liquid reaches a predetermined level has achieved, even if it is a foaming, is electrically non-conductive or a solids-carrying liquid, which with the wet vacuum to be sucked up.

These Task is renewal by the Characteristics of claim 1 solved. Further, particularly advantageous embodiments of the invention reveal the dependent claims.

The Innovation is based essentially on the idea of temperature change take advantage of the corresponding, initially surrounded by air sensor learns when he is with the sucked liquid in touch comes. It is therefore proposed, in the range of critical level height at least to arrange a temperature sensor, which in contact with the ascending Liquid generated corresponding switching signal, which then from a control and processing unit further processed and optionally to shutdown the suction device or used to display a warning message can be.

When Advantageously, it has proven to be a temperature sensor thermoresistive sensor (i.e., a sensor whose electrical conductivity temperature-dependent is) is used. In particular, the use has NTC thermistors (thermistor) or PTC thermistors (PTC thermistors) as appropriate.

in the Case of using a PTC thermistor turns to electrical Load one of the respective cooling condition appropriate balance between the supplied electrical and the derived thermal energy. The immersion of the PTC thermistor in a liquid elevated the thermal conductivity and hence the power consumption, with the resulting current change serves for signaling.

Of the respective temperature sensor may optionally be part of the Supply lines in a protective housing Made of plastic or stainless steel and resistant and stable in the distance to the container wall be held, wherein the respective sensor in the protective housing means an electrically non-conductive casting compound, for example made of plastic, can be fixed and very insensitive to moisture etc. is.

Although the use of a protective housing and the casting by means of a corresponding mass usually causes a certain delay in the response of the sensor, but this is in many cases quite desirable to premature reaction of this highly sensitive component already on moisture mist (moist air, fine mist , light foam or the like.) To prevent. Should droplet droplets on the sensor These are immediately miterhitzt and do not lead to a change in power consumption. However, if the heated sensor comes in contact with cool liquid or heavy foam, the desired change in power consumption occurs.

Should with a wet vacuum in the long term very warm to hot liquids be sucked, so the use of a thermistor is provided, the Power consumption changes with temperature increases.

Provided a wet vacuum for sucking up normal or cool liquids as well as for sucking up by hot liquids is used, it makes sense as a combination of sensors Cold and hot conductors to use.

Further Details and advantages of the innovation emerge from the following, explained with reference to figures Embodiments. Show it:

1 schematically the partially sectioned side view of a Naßsaugers according to the invention and

2 an enlarged view of the in 1 with II designated section.

In 1 is with 1 an inventive Naßsauger referred to, which is a sucker, both solids (eg metal shavings) 2 as well as liquids (or emulsions) 3 should absorb, with the solids 2 and the liquid 3 are separately disposable.

The wet vacuum 1 consists essentially of a chassis 4 on which a per se known suction device (suction blower unit) 5 and a receptacle 6 are attached. In this case, the receptacle 6 for emptying the liquid 3 on his the chassis 4 facing side a tap 7 on. To absorb the solids 2 is in the upper area of the receptacle 6 a solid container 8th provided, which by lifting a lid 9 from the receptacle 6 is removable and can be emptied.

The lid 9 of the receptacle 6 has both a first pipe socket 10 on, with an intake, not shown, for absorbing the solids 2 and the liquid 3 is connectable, as well as a second pipe socket 11 who has a flexible line 12 with the suction device 5 connected is.

Furthermore, the Naßsauger contains a device 100 for monitoring the liquid level 101 in the receptacle 6 located liquid 3 , This device 100 comprises according to the invention a temperature sensor 13 ( 2 ), which is in the range of the critical fill level (here slightly below the solids container 8th ) on the inner wall 14 of the receptacle 6 is arranged. In this case, have as temperature sensors 13 especially thermoresistive sensors proven in practice (in the illustrated embodiment, for example, a PTC thermistor (PTC thermistor) was used).

As soon as the rising liquid during the suction process the temperature sensor 13 touched, in the case of using a thermoresistive sensor, a change in the conductivity of the corresponding sensor 13 because the temperature of the liquid 3 usually different from that of the air 15 that previously the temperature of the sensor 13 has determined. This conductivity change of the sensor 13 is from a control and evaluation unit 16 the device 100 evaluated and for generating a switching signal for switching off the suction device 5 used.

As 2 is removable, there is the actual temperature sensor 13 with its connecting wires 17 in a protective housing, for example made of stainless steel 18 , wherein the cavity of the protective housing 18 with a corresponding, electrically insulating plastic compound 19 is poured out.

The Invention is self-evident not limited to the embodiment described above. So The wet vacuum according to the invention also more than just a temperature sensor to monitor the fluid level exhibit. In a further, not shown embodiment For example, two spaced-apart temperature sensors were used used, wherein it is a temperature sensor to an NTC thermistor and the other temperature sensor is a PTC thermistor.

In addition, can the sensor signal generated by the temperature sensor also for display warnings (e.g., of light and / or sound signals) become.

1

wet vacuum

2

solids

3

liquid

4

chassis

5

suction

6

receptacle

7

tap

8th

Solid container

9

cover

10

(First) pipe socket

11

(Second) pipe socket

12

management

13

Temperature sensor, sensor

14

inner wall

15

air

16

Tax- and evaluation unit

17

connecting wire

18

housing

19

Plastic compound

100

contraption

101

liquid level

Claims (6)

Wet vacuum cleaner, in particular for liquids containing solids, with a suction device ( 5 ), the liquid ( 3 ) receiving receptacles ( 6 ) and a device ( 100 ) for monitoring the liquid level ( 101 ) in the receptacle ( 6 ), the device ( 100 ) at least one sensor ( 13 ) in the range of a predetermined maximum filling level and one outside the receiving container ( 6 ), with the sensor ( 13 ) connected control and evaluation unit ( 16 ), which is a shutdown of the suction device ( 5 ) and / or activates a display device when the liquid ( 3 ) has reached the predetermined maximum filling level, characterized in that the sensor ( 13 ) is a temperature sensor. Wet vacuum according to claim 1, characterized in that the temperature sensor ( 13 ) is a thermoresistive sensor. Wet vacuum according to claim 2, characterized in that the temperature sensor ( 13 ) is an NTC thermistor or a PTC thermistor. Wet vacuum cleaner according to claim 3, characterized in that the temperature sensor ( 13 ) in a protective housing ( 18 ) is made of plastic or stainless steel. Wet vacuum according to claim 4, characterized in that the temperature sensor ( 13 ) within the protective housing ( 18 ) in a plastic mass ( 19 ) is poured. Wet vacuum cleaner according to claim 1, characterized in that the device ( 100 ) for monitoring the liquid level comprises two spaced-apart temperature sensors, wherein it is a temperature sensor to an NTC thermistor and the other temperature sensor is a PTC thermistor.