Process water sampling immersion probe

Abstract

The present invention relates to a process water sampling immersion probe (10), A filter module (20) equipped with a filter screen (24, 24'), In the vertical direction, a cleaning air generator (40) is positioned adjacent to the vertical lower end (d24) of the filter screen (24, 24'), Equipped with, The cleaning air generator (40) includes a bubble generator housing (41) equipped with air outlet openings (51, 52) having a non-horizontal opening surface (p54), The air outlet openings (51, 52) of the process water sampling immersion probe (10) expand vertically downward such that the upper width (wt54) of the air outlet opening at the upper end (t54) of the opening is smaller than the lower width (wd54) of the air outlet opening at the lower end (d54) of the opening.

Description

Technical Field

[0001] The present invention relates to a process water sampling submerged probe for continuously filtering water samples from wastewater.

Background Art

[0002] Stationary process water sampling submerged probes are used as part of process water analyzers for analyzing one or more target substances in water, such as wastewater in wastewater tanks that are part of, for example, wastewater treatment facilities.

[0003] A typical stationary water sampling submerged probe is disclosed in Patent Document 1. The water sampling submerged probe is provided with two filter screens each lying in a filter screen plane inclined relative to the vertical axis of the earth. At the lower end of each filter screen, a plurality of air outlet openings are arranged in a horizontal row, through which pressurized air is discharged, thereby generating a cleaning air bubble curtain along the assigned filter screen. Deposits can grow on the air outlet openings due to substances in the wastewater and cause clogging, which continuously degrades the cleaning quality of the air curtain. Accordingly, the air outlet openings need to be manually cleaned from time to time, which is cumbersome. The air pump that supplies the pressurized cleaning air must operate continuously to reduce the tendency for clogging and the clogging rate over time.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problem to be Solved by the Invention

[0005] The objective of this invention is to improve the handling and performance of process water sampling immersion probes. [Means for solving the problem]

[0006] The sampling immersion probe also includes a cleaning air generator positioned vertically adjacent to the lower vertical end of the filter screen. The cleaning air generator includes a bubble generator housing having at least one air outlet opening, the air outlet opening having a non-horizontal opening surface.

[0007] Preferably, at least two air outlet openings are provided in the bubble generator housing. The cleaning air pressurized into the bubble generator housing is discharged through the air outlet openings, thereby generating bubbles distal to the air outlet openings, which rise along the distal surface of the filter screen with a vertical component. The opening surface of the air outlet opening is not in a horizontal plane, but rather in a more vertically inclined plane or a perfectly vertical plane.

[0008] The air outlet opening has a vertical upper end and a vertical lower end, but the horizontal upper width at the upper end of the air outlet opening is smaller than the lower width at the lower end of the air outlet opening. The width of the air outlet opening is the distance horizontally from one point on the opening edge to the opposite point on the opposite opening edge.

[0009] In general, especially in wastewater applications, it is impossible to completely avoid clogging of the air outlet opening. Because the air outlet opening expands downward horizontally, the pressure difference between the pressurized cleaning air inside the bubble generator housing and the wastewater outside the bubble generator housing causes a destructive force against the clogging structure, while the total destructive force increases proportionally to the horizontal width of the air outlet opening. Even if the clogging structure is relatively strong, it will break at a relatively low position in the air outlet opening where the air outlet width is relatively large. Another effect of the downward-extending air outlet opening is that the clogging structure is continuously eroded by the cleaning airflow at the horizontal center of the air outlet opening, which results in a concave effect at the center of the clogging structure. The vertical position of the true air outlet may change depending on the vertical extension of the clogging structure within the air outlet opening, but the horizontal position of the true air outlet does not change substantially and is relatively precisely defined at the horizontal opening center regardless of the vertical extension of the clogging structure.

[0010] As a result, the structure of the bubble carpet is not substantially affected by clogging of the air outlet opening. Since clogging of the air outlet opening does not substantially affect the structure and quality of the cleaned air bubble carpet, it is not necessary to operate the cleaned air pump continuously at maximum pressure performance, thereby extending the life of the cleaned air pump.

[0011] The process water sampling immersion probe was field-tested in a wastewater treatment plant tank in 2023. Even after 160 days without manual cleaning of the water sampling immersion probe, the cleaning air generator functioned without any degradation related to the quantity and quality of the bubble curtain produced. As a result, the pump performance for continuously pumping filtered wastewater from the process water sampling immersion probe to the onshore analysis station only decreased from 1600 ml / h to 1400 ml / h. As a practical result, the interval between manual cleanings can be significantly extended by at least two times.

[0012] Preferably, the air outlet opening expands continuously between the upper and lower ends of the opening. The width of the air outlet opening expands continuously, rather than in steps, from the upper vertical end to the lower vertical end of the air outlet opening.

[0013] Preferably, the air outlet opening is substantially inverted V-shaped, while the side edges of the air outlet opening are not necessarily straight but may be curved, thereby defining a gradual vertical increase in the opening width in the vertically downward direction. More preferably, the average total opening angle of the inverted V-shaped air outlet opening is greater than 15°, and more preferably greater than 30°.

[0014] Preferably, each filter screen is provided with at least two air outlet openings. More preferably, two parallel filter screens are provided, each filter screen being provided with at least two air outlet openings.

[0015] Preferably, the bubble generator housing has an inverted cup-shaped structure with a housing opening having a horizontal housing opening surface. The air outlet opening extends into the horizontal housing opening, so that the air outlet opening does not have an opening edge closing the lower side of the air outlet opening. The lower end of the air outlet opening extends seamlessly into the horizontal housing opening. As a result, the air outlet opening is easily accessible from the bottom surface of the bubble generator housing and can be easily cleaned mechanically, either manually or automatically.

[0016] Preferably, the bubble generator housing has substantially vertical side walls with air outlet openings. As a result, the lateral distance of the true air outlet, as defined by the clogging structure, remains constant with respect to the general surface of the filter screen, thereby ensuring that bubbles exiting the cleaning air generator always remain close to the filter screen, regardless of the expansion of the clogging structure within the air outlet opening.

[0017] Preferably, a guide device having a vertical guide wall is provided to guide the bubble curtain. The guide wall is set distal to the corresponding filter screen in the horizontal direction, thereby defining a vertical bubble channel between the filter screen and the guide wall. The vertical bubble channel holds the bubble carpet close to the filter screen, thereby maintaining a constant cleaning effect across the entire vertical height of the filter screen. Preferably, the guide wall completely covers the corresponding filter screen when viewed horizontally. More preferably, the vertical guide wall has a lower edge that is not above the air outlet opening in the vertical direction.

[0018] Preferably, the bubble generator housing is provided with an air inlet opening through which pressurized cleaning air passes when it is pumped into the bubble generator housing by a suitable pump. The lowest edge of the air inlet opening is at least 1.0 mm vertically above the upper edge of the air outlet opening. The wastewater surface level always remains vertically below the air inlet opening, thereby ensuring that the air inlet opening is safe from clogging caused by substances in the wastewater.

[0019] Preferably, a check valve is provided upstream of the cleaning air inlet opening, and more preferably, at a fluid distance of less than 15 cm from the cleaning air inlet opening. The check valve opens in the direction of the flow of cleaning air being pumped into the bubble generator housing. Even when the cleaning air pump is not operating, the static pressure of the air cushion in the bubble generator housing 41 remains relatively high, thereby keeping the wastewater level below the cleaning air inlet opening.

[0020] According to independent claim 13, there is provided a process water sampling apparatus comprising a process water sampling immersion probe having the features of any one of the preceding claims. The process water sampling apparatus further includes a cleaning air pump and an intermittent operation pump control unit that intermittently operates and stops the cleaning air pump. The cleaning air pump is intermittently operated and stopped, for example, according to a stored cleaning schedule, or by measurement of a clogging structure at an outlet opening or a specified height. Since the cleaning air pump is not driven continuously, the service life of the cleaning air pump can be significantly extended.

[0021] One embodiment of the present invention will be described below with reference to the drawings. [Brief Description of the Drawings]

[0022] [Figure 1] Schematically shows a process water analysis apparatus having a process water sampling immersion probe viewed in a vertical cross section. [Figure 2] Shows the process water sampling immersion probe of Fig. 1 in more detail. [Mode for Carrying Out the Invention]

[0023] Figure 1 schematically shows a process water analysis apparatus 100 for continuously analyzing a water sample of wastewater W. Wastewater W continuously flows into the wastewater tank 130 through the tank inlet, and continuously flows out from the wastewater tank 130 through the tank outlet, so that a general wastewater flow is generated in the wastewater tank 130. Alternatively, the wastewater tank 130 may be filled and discharged at intervals. The wastewater tank 130 may be part of a wastewater treatment facility.

[0024] The process water analysis apparatus 100 is provided for quasi-continuously identifying the concentration of one or more analytes in wastewater W, for example, ammonium and / or phosphate.

[0025] The process water analyzer 100 essentially comprises a process water sampling immersion probe 10, which is completely immersed in wastewater W and held in place by a rigid holding structure (not shown). The immersion probe 10 is hydrodynamically, electrically, and / or electronically connected to a land-based analyzer station 105, which comprises an electric sample pump 132, an electric wash air pump 110, an electronic intermittent operation pump control unit 122 that controls the wash air pump 110, and an analyzer unit 120 for analyzing the concentration of one or more test substances in a water sample of wastewater W.

[0026] The immersion probe 10 is generally provided as a flat, planar rectangular body substantially comprising a filter module 20 having two parallel vertical filter screens 24, 24', a cleaning air generator 40 positioned directly adjacent to the vertical lower end of the filter module 20 in the vertical direction, and a flow guide device 30 having two vertical guide walls 34, 34'.

[0027] The two filter screens 24 and 24' of the filter module 20 are each located in a vertical plane yz and are parallel to each other, and together with the two vertical side walls 33 and 33', the horizontal bottom wall 38, and the horizontal top wall 39, they surround a rectangular filter module cavity 36. At the upper end of the filter module cavity 36, the housing of the filter module 20 has a sample outlet opening 32, and the filtered water sample is continuously pumped through the sample outlet opening 32 to the analyzer unit 120 via the sample line 133 by the sample pump 132. The analyzer unit 120 semi-continuously determines the concentration of each test substance in the water sample.

[0028] The cleaning air generator 40 is positioned in the vertical direction close to the lower vertical ends d24 of the two filter screens 24, 24' and directly adjacent to the bottom wall 38 of the filter module housing. The cleaning air generator 40 comprises a substantially rectangular bubble generator housing 41 having a total of four air outlet openings 51, 52. The opening surfaces p54 of the air outlet openings 51, 52 are each in the vertical plane yz and are in substantially the same vertical plane as the corresponding filter screens 24, 24'. As shown in Figure 2, the rectangular bubble generator housing 41 is provided with a horizontal top wall 42, two vertical end walls 46, 47 parallel to each other, and vertical side walls 44, 45, each having two air outlet openings 51, 52. The bubble generator housing 41 has an inverted cup-shaped structure, enclosing the rectangular housing interior 60, and has no bottom wall, defining a horizontal housing bottom opening 50 with a horizontal housing opening surface p50.

[0029] A cleaning air inlet opening 141 is provided on one end wall 47 of the bubble generator housing 41. When the cleaning air pump 110 is operating, pressurized cleaning air is pumped through this opening into the interior 60 of the bubble generator housing. When the cleaning air pump 110 is operating, cleaning air is drawn in through a suction opening 126 and pumped through the cleaning air line 111 to the cleaning air inlet opening 141. Two check valves 116 and 117 are provided along the path of the cleaning air line 111. One check valve 116 is located adjacent to the upstream side of the cleaning air inlet opening 141, and the other check valve 117 is located relatively close to the downstream side of the cleaning air pump 110. However, under normal circumstances, only one check valve is required, which is preferably the check valve 116 located close to the cleaning air inlet opening 141.

[0030] Each vertical bubble generator housing side wall 44, 45 is provided with two air outlet openings 51, 52. The air outlet openings 51, 52 are designed to widen continuously horizontally downward vertically, as shown in Figure 2. The four air outlet openings 51, 52 are identical in shape and are substantially symmetrical inverted V-shapes with a total opening angle A of approximately 50°. Each air outlet opening 51, 52 has a vertical opening surface p 54. The horizontal opening upper width wt 54 at the upper end t 54 of the opening is smaller than the opening lower width wd 54 at the lower end d 54 of the opening, as shown in Figure 2. The edges 54 of the air outlet openings 51, 52 transition to the horizontal opening edge of the horizontal housing bottom opening 50 of the bubble generator housing 41. As a result, the air outlet openings 51, 52 are fully accessible in the vertical direction y for manual cleaning of the air outlet openings 51, 52.

[0031] As shown in Figure 2, the upper ends or upper edges of the air outlet openings 51, 52 have a vertical distance y54 at least 2 cm below the lowest opening edge of the cleaning air inlet opening 141 of the bubble generator housing 41.

[0032] As shown in Figure 1, the process water sampling immersion probe 10 is provided with a guide device 30 having two planar vertical guide walls 34, 34' parallel to each other and to the filter screens 24, 24'. Each guide wall 34, 34' is set back several centimeters horizontally from the corresponding filter screens 24, 24', thereby defining vertical bubble channels 28, 28' between the filter screens 24, 24' and the corresponding guide walls 34, 34'. As shown in Figure 1, the straight lower edges e34 of both guide walls 34, 34' are not vertically above the air outlet openings 51, 52, but slightly below the lower edges d54 of the air outlet openings 51, 52.

[0033] The intermittent operation pump control unit 122 is provided with an operation schedule memory 123 for storing the intermittent operation schedule of the cleaning air pump 110. The intermittent operation pump control unit 122 controls the operation of the cleaning air pump 110 by intermittently switching it on and off with, for example, a 50% on rate and an interval length of, for example, a full on / off cycle of 5 minutes. Alternatively or additionally, the operation of the cleaning air pump 110 may be controlled by a closed-loop control circuit that includes a clogging sensor for measuring the degree of clogging of the air outlet openings 51, 52.

Claims

1. A process water sampling immersion probe (10), A filter module (20) equipped with a filter screen (24, 24'), In the vertical direction, a cleaning air generator (40) is positioned adjacent to the vertical lower end (d24) of the filter screen (24, 24'), Equipped with, The cleaning air generator (40) includes a bubble generator housing (41) equipped with air outlet openings (51, 52) having a non-horizontal opening surface (p54), The process water sampling immersion probe (10) has air outlet openings (51, 52) that expand vertically downward such that the upper width (wt54) of the air outlet opening at the upper end (t54) of the opening is smaller than the lower width (wd54) of the air outlet opening at the lower end (d54) of the opening.

2. The process water sampling immersion probe (10) according to claim 1, wherein the air outlet openings (51, 52) expand continuously between the upper end (t54) and the lower end (d54) of the air outlet openings (51, 52).

3. The process water sampling immersion probe (10) according to claim 1 or 2, wherein the air outlet openings (51, 52) are substantially in the shape of an inverted V.

4. The process water sampling immersion probe (10) according to claim 3, wherein the average opening angle (A) of the inverted V-shaped air outlet openings (51, 52) is greater than 15°, more preferably greater than 30°.

5. The process water sampling immersion probe (10) according to claim 1 or 2, wherein at least two air outlet openings (51, 52) are assigned to one filter screen (24, 24').

6. The process water sampling immersion probe (10) according to claim 1 or 2, wherein the bubble generator housing (41) has a cup-shaped structure with a housing opening (50) having a horizontal housing opening surface (p50) such that the air outlet openings (51, 52) do not have an opening edge at their lower end.

7. The process water sampling immersion probe (10) according to claim 1 or 2, wherein the bubble generator housing (41) comprises substantially vertical side walls (44, 45) having the air outlet openings (51, 52).

8. The process water sampling immersion probe (10) according to claim 1 or 2, wherein the filter screen (24, 24') is arranged vertically.

9. A process water sampling immersion probe (10) according to claim 1 or 2, comprising a flow guide device (30) having vertical guide walls (34, 34'), wherein the guide wall (34) is separated distally from the corresponding filter screen (24, 24'), thereby defining a vertical bubble channel (28, 28') between the filter screen (24, 24') and the guide wall (34, 34').

10. The process water sampling immersion probe (10) according to claim 9, wherein the vertical guide wall (34, 34') has a lower edge (e34) that is not located above the air outlet opening (51, 52) in the vertical direction.

11. The process water sampling immersion probe (10) according to claim 1 or 2, wherein the upper end of the air outlet opening (51, 52) has a vertical distance (y 54) of at least 1.0 mm below the cleaning air inlet opening (141) of the bubble generator housing (41).

12. The process water sampling immersion probe (10) according to claim 1 or 2, wherein the cleaning air flows into the bubble generator housing (41) through the cleaning air inlet opening (141), and a backflow prevention valve (116, 117) is provided upstream of the cleaning air inlet opening (141).

13. A process sampling apparatus (100) comprising a process water sampling immersion probe (10) according to claim 1 or 2, further comprising a cleaning air pump (110) and an intermittent operation pump control unit (122) for intermittently operating the cleaning air pump (110).

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