WATER SAMPLING IMMERSION PROBE

Abstract

The present invention relates to a water sampling immersion probe (50) for continuously filtering a water sample from wastewater (14). The water sampling immersion probe (50) includes a distal coarse filter (60) with a porosity of 0.1 to 1.0 mm, a proximal fine filter (70) arranged downstream of the coarse filter (60) and having a porosity of less than 5.0 μm, and a sample suction opening (74) arranged downstream of the fine filter (70). The coarse filter (60) is arranged to not contact the fine filter (70).

Claims

1.-15. (canceled)

16. A water sampling immersion probe for continuously filtering a water sample from wastewater, the water sampling immersion probe comprising: a distal coarse filter comprising a porosity of 0.1 to 1.0 mm; a proximal fine filter arranged downstream of the distal coarse filter, the proximal fine filter comprising a porosity of less than 5.0 μm, the distal coarse filter and the proximal fine filter being arranged so as to not contact each other; and a sample suction opening arranged downstream of the proximal fine filter.

17. The water sampling immersion probe of claim 16, wherein a space between the distal coarse filter and the proximal fine filter defines a venting chamber which comprises at least one venting opening through which venting air can be blown into the venting chamber.

18. The water sampling immersion probe of claim 16, wherein the proximal fine filter is defined by a fine filter membrane which is air-impermeable.

19. The water sampling immersion probe of claim 16, wherein the distal coarse filter is defined by a coarse filter membrane which is self-supporting.

20. The water sampling immersion probe of claim 16, wherein the distal coarse filter is defined by a coarse filter membrane which is at least one of self-supporting and comprises a lipophilic surface.

21. The water sampling immersion probe of claim 16, further comprising: a suction chamber arranged downstream of the proximal fine filter; and a separate stiff support body arranged in the suction chamber which mechanically supports the proximal fine filter and which is permeable to water.

22. The water sampling immersion probe of claim 19, wherein the coarse filter membrane of the distal coarse filter is substantially flat.

23. The water sampling immersion probe of claim 22, wherein, the coarse filter membrane of the coarse filter and the fine filter membrane of the fine filter are each flat and are arranged substantially parallel to each other, and a general plane of each of the coarse filter membrane, the fine filter membrane, and the resulting venting chamber are inclined with respect to the vertical (V) at an inclination angle (a) of 5° to 80°, and more preferably, at the inclination angle (a) of 10° to 40°.

24. The water sampling immersion probe of claim 19, wherein the proximal fine filter is defined by a fine filter membrane, wherein the coarse filter membrane and the fine filter membrane are each generally cylindrical in shape and are arranged coaxially with respect to each other.

25. The water sampling immersion probe of claim 24, wherein, the venting chamber is generally cylindrical, and the venting opening is arranged at a vertically lowest region of the venting chamber.

26. The water sampling immersion probe of claim 17, wherein, the water sampling immersion probe is generally cylindrical and comprises a cylinder axis, and the cylinder axis of the immersion probe is inclined with respect to a horizontal (H) at an inclination angle (A′) of 10° to 80°.

27. The water sampling immersion probe of claim 16, further comprising: a protection fork comprising at least two fork tines, the protection fork being arranged distal of and at the outside of the coarse filter membrane, wherein, a lateral tine distance (D) of two neighboring fork tines of the at least two fork tines is 5 to 50 mm.

28. The water sampling immersion probe of claim 27, wherein, each of the at least two fork tines comprise a free end and at least one closed end, and the free end of each of the at least two fork tines are arranged downstream in a direction of a flowing wastewater, and the free end of each of the at least two fork tines is arranged higher than the at least one closed end of the at least two fork tines in the direction of the flowing wastewater.

29. The water sampling immersion probe of claim 28, further comprising: a next upstream flow resistance structure, wherein, a distance (X) between the at least one closed end of the at least two fork tines and the next upstream flow resistance structure is at least 50 mm.

30. A process water analysis arrangement for continuously analyzing a water sample of wastewater, the process water analysis arrangement comprising: a water sampling immersion probe for continuously filtering a water sample from wastewater, the water sampling immersion probe comprising: a distal coarse filter comprising a porosity of 0.1 to 1.0 mm; a proximal fine filter arranged downstream of the distal coarse filter, the proximal fine filter comprising a porosity of less than 5.0 μm, the distal coarse filter and the proximal fine filter being arranged so as to not contact each other; and a sample suction opening arranged downstream of the proximal fine filter; a control unit comprising a sample pump, and a water analysis apparatus, wherein, the water analysis apparatus is fluidically connected to the sample suction opening so that the water sample is pumped from the water sampling immersion probe by the sample pump to the water analysis apparatus.

Description

[0029] Two embodiments of the present invention are described below with reference to the drawings, wherein:

[0030] FIG. 1 schematically shows a process water analysis arrangement including a first embodiment of a generally flat and plane water sampling immersion probe provided in a wastewater tank and including an control unit with a water analysis apparatus which is arranged remote from the immersion probe;

[0031] FIG. 2 shows the process water analysis arrangement of FIG. 1 in greater detail;

[0032] FIG. 3 shows a second embodiment of a water sampling immersion probe with a generally cylindrical shape; and

[0033] FIG. 4 shows a cross-section of the water sampling immersion probe of FIG. 3.

[0034] FIG. 1 schematically shows a process water analysis arrangement 10 for continuously analyzing water samples of wastewater 14. The wastewater 14 continuously flows into a primary wastewater tank 12 through a tank inlet 16, and continuously flows out of the wastewater tank 12 through a tank outlet 18, so that a general wastewater flow 20 is generated within the wastewater tank 12 between the inlet 16 and the outlet 18. The process water analysis arrangement 10 is provided for quasi-continuously determining one or more analytes of the wastewater 14, for example, ammonium and/or phosphate and can be a part of a wastewater treatment plant.

[0035] The process water analysis arrangement 10 basically comprises a water sampling immersion probe 50 which is immersed into the wastewater 14 and which is held and positioned by a stiff holding structure 54. The immersion probe 50 is fluidically and electronically connected to a land-sided control unit 30 comprising a sample pump 34, a venting air pump 32 and a water analysis apparatus 36 for analyzing one or more analyte of a water sample of the wastewater 14. The analysis apparatus 36 can alternatively be provided remote from the control unit 30 in a control center of the wastewater treatment plant, whereas the control unit 30 with the pumps 32, 34 is located as close as possible to the immersion probe 50.

[0036] FIG. 2 shows a first embodiment of a water sampling immersion probe 50 in greater detail. The immersion probe 50 is generally provided as a flat, plane and rectangular body which is defined by a probe housing 52 defining a generally plane and rectangular probe opening 56 at the distal side of the probe housing 52. The probe opening 56 is closed by a distal coarse filter 60 which is defined by a coarse filter membrane 62 with a porosity of about 0.6 mm. The coarse filter membrane 62 is made of stainless steel, is stiff and self-supporting, and has a lipophilic surface.

[0037] A fine filter 70 is provided proximal of the coarse filter 60. The fine filter 70 is defined by a plastic fine filter membrane 72 which is substantially air-impermeable and which has a nominal porosity of 50 μm.

[0038] The fine filter membrane 72 and the coarse filter membrane 62 do not contact or touch each other, but are provided with a constant distance of a few millimeters to each other over the entire plane surface of the filters 60,70. The space between the coarse filter 60 and the fine filter 70 defines a plane and rectangular venting chamber 66 which is not filled with any solid substance. The rectangular and generally plane space proximal of the fine filter membrane 72 defines a suction chamber 76 which is completely filled with a separate stiff support body 77 which mechanically supports the fine filter membrane 72. The support body 77 is a stiff plastic body which is permeable to water and air.

[0039] The coarse filter membrane 62 and the fine filter membrane 72 are arranged substantially parallel to each other. The general planes of the coarse filter membrane 62 and the fine filter membrane 72 are inclined with respect to the vertical V with an inclination angle a of about 15°.

[0040] Numerous venting openings 64 are provided at the bottom of the venting chamber 66 through which venting air bubbles 19 enter the venting chamber 66 and rise upwards along the distal surface of the fine filter membrane 72. The venting openings 64 are provided with venting air via a venting tube 63 which fluidically connects the venting openings 64 with the venting air pump 32 provided at the control unit 30. The air bubbles 19 finally exit the venting chamber 66 through the small pores of the coarse filter membrane 62, and thereby mechanically clean the coarse filter membrane 62 from substances adhering to the distal side of the coarse filter membrane 62.

[0041] The sample pump 34 can, alternatively, be provided at the immersion probe 50.

[0042] The suction chamber 76 proximal of the fine filter membrane 72 is provided with a sample suction opening 74 through which the filtered water sample is sucked out of the suction chamber 76 and pumped by a sample pump 34 provided at the control unit 30 to the water analysis apparatus 36 of the control unit 30 via a sample line 73.

[0043] The process water analysis arrangement 10 generally works intermittently so that a sample suction and analyzing interval is followed by a venting interval which is followed by a sample suction and analyzing interval etc.

[0044] An almost continuous sample flow and analysis can be realized by two immersion probes which are working in an alternating manner.

[0045] FIGS. 3 and 4 show a second embodiment of a water sampling immersion probe 50′ which is not designed to be generally flat, but which is designed to have a generally cylindrically shape. The reference signs in FIGS. 3 and 4 are generally provided with an apostrophe if the corresponding parts and features are designed differently, but have the same function as at the immersion probe 50 of the first embodiment shown in FIG. 2.

[0046] As can be seen best in FIG. 4, the generally cylindrical concept of the immersion probe 50′ results in a generally cylindrical coarse filter 60′ with a cylindrical coarse filter membrane 62, a generally cylindrical fine filter 70′ with a cylindrical fine filter membrane 72′, a generally cylindrical and ring-like venting chamber 66′, and a generally cylindrical suction chamber 76′ with the generally cylindrical support body 77′.

[0047] The immersion probe 50′ is provided with numerous venting openings 64′ at the ring-like cylinder bottom wall of the venting chamber 66′. Four sample suction openings 74′ are provided at the proximal suction chamber surface from where the water sample flows to the sample line 73.

[0048] As can be seen in FIG. 3, the cylinder axis 51 of the generally cylindrical immersion probe 50′ is inclined with respect to the horizontal H in an inclination angle a′ of about 20°.

[0049] The immersion probe 50′ is provided with a generally cylindrical protection fork 80 with six fork tines 90 surrounding the immersion probe 50, and in particular surrounding the coarse filter membrane 72′. The fork tines 90 are generally provided parallel to each other, and the cylinder defined by the fork tines 90 is provided coaxially with the cylindrical immersion probe 50′. The fork tines 90 have a substantially constant cross-section over their entire length.

[0050] The orientation of the immersion probe 50′ including the protection fork 80 is chosen so that the free ends 91 of the fork tines 90 are at the lee side with respect to the wastewater flow 20 in the wastewater tank 12. The lateral distance D of the fork tines 90 to each other is about 20 mm. The closed ends 81 of the fork tines 90 are provided with a distance X of about 50 mm from the next upstream flow resistance structure 83. The flow resistance structure 83 in this case is a bow shoulder of the probe holding structure 54′ which is, in this embodiment, generally cylindrical in cross section and has the same diameter as a cylindrical fork basis 82 of the protection fork 80.