EP0672801B1 - Screen element, gully and street and sewer cleaning vehicle comprising such a screen element - Google Patents

Abstract

The sieve component comprises a sieve plate with several systematically arranged trickle holes (17). These trickle holes are arranged in parallel, spaced, running horizontally and superimposed rows. They are screened by downwardly facing screen components (18) at an angle. Dewatering material or cleaning material (56) cannot accumulate directly in front of the trickle holes. It instead forms a trickle channel in the wedge-shaped corner between the sieve plate and the screening components.

Description

The invention relates to a screen element, a drainage trough as well as a street or sewer cleaning vehicle with such a sieve element.

Drainage troughs serve as collection containers for Items to be cleaned or waste containing a lot of water, which should run as much as possible. For example in such troughs, screenings from sewage treatment plants or collected sewer cleaning items. such a Well still contains a substantial amount of water, the should be removed before the troughs are removed, to use the trough volume primarily for the solids and not unnecessarily loaded with water. At the same time the drainage of the goods during storage in the trough pre-drying if the product is subsequently further processed, e.g. is burned. To the water of the groupage Drainage troughs have drainage troughs at least in a wall or corner Perforated sheet. However, these perforated sheets are relatively set quickly too, so that water drainage is inhibited and drainage is insufficient. If possible, will then tried from the inside of the trough or from the outside Scrape, poke or rinse perforated sheets. In in practice, one helps oneself to clog the Prevent perforated sheets by using a coarse filter acting stone layer in front of the perforated plate.

A similar, but probably more essential problem exists in those aimed at water recovery Drainage of sweepings or sewer cleaning material, the Pick up street sweeping and sewer cleaning vehicles. First the development of road sweeping vehicles is discussed. In road sweeping vehicles, the dirt is removed rotating brushes of various designs or over one Suction mouth added. The debris consists of a substantial Dust content. This was the case with older sweepers Dust whirled around inside the machine and for the most part blown back into the free atmosphere with the exhaust air flow. A first improvement brought sweepers where Water from a tank integrated in the vehicle body was sprayed onto the sweeping surface to prevent contamination, especially from grooves in the street surface, to flush it out and, on the other hand, to bring the dust to the water tie. This made it possible for the dust whirled up caused pollution can be significantly reduced. at this type of machine had to be a large one Water tank should be provided or the tank content was soon sprayed, because the water was sprayed only once and was therefore lost (see for example the DE-AS 12 17 424).

A further development is from DE-PS 25 45 137 known. The sweeper proposed therein is in the Sweeping chamber with a sieve on which the essential Water content separated from the muddy debris and is returned to the water cycle. To this In this way, multiple use of the water is achieved, thereby the water tank can be made smaller and at the same time the duration of use of the cleaning vehicle with a Water tank filling increased. Through the sieve arrangement the bulk of the sweepings was retained, the separated However, water is heavily contaminated, which leads to disturbing deposits and blockages of the nozzles leads as well heavy wear in the flow-through units, especially pumps.

From DE-GM 91 11 692 a device is known which should enable water in a sweeper of higher purity, which then is used again. For this purpose, the water recovery device contains a multi-chamber system with the fineness graduated filter walls and downstream backwashable Fine filters. The equipment structure required here is very high complex and as far as the throughput of waste water is concerned, the device is only of limited performance. In addition, the filter walls as well as the fine filters must be used frequently cleaned or renewed frequently.

Often even larger amounts of dirty water are in Treat sewer cleaning vehicles. You are here too in order to recover the water as far as possible a reservoir of rinsing water integrated in the vehicle endeavor. Deposits are removed with a pressurized water jet washed away in a channel section and the deposit-laden Rinsing water sucked back into the vehicle. There is a more or less rough separation between Solids and water after that also used in sweepers Principle - with the same shortcomings - instead of. The water is separated using the known sieve walls and filter arrangements. So far, roughly purified water is returned to the reservoir and from here used again for pressure flushing.

The previously known devices for water separation in drainage troughs or for water recovery in street sweeping and sewer cleaning vehicles all in terms of their cost-benefit ratio not as be rated optimally. As disadvantages - they occur alternatively or in combination on - are to be mentioned in particular: insufficient purity of the recovered water, too fast blockage of the used separators, elaborate apparatus construction and too low throughput.

Such a separator is known from FR-A-2 215 396 known a domestic water tank, the one in the installed state in has substantially vertically arranged sieve plate. The Separator has trickle breakthroughs, before which pre-folds are provided as shielding elements for the Giant breakthroughs serve. The pre-folds form together with the wall of the sieve element thin, lamellar channels through which the water has to get to the trickle breakthroughs to passing through the trickle openings on the beyond wall to be able to drain the sieve element into a trough, where any solids still in the water accumulate The bottom of the trough. The folds on the this side wall of the sieve element, i.e. on the wall, which facing the sludge act as siphons, which with increasing sludge level from the sludge be closed so that the water can no longer pass through such a closed channel and through the associated Giant breakthrough can get through, but only through the next higher open channel on the other side can get into the trough.

The aim of the invention is therefore a device with improved efficiency at low to create equipment expenditure. It is also said to the device may be possible, even large, muddy Dirty water quantities and debris with less water content with sufficient purity to separate water and solids, without quickly clogging fine filters Need to become. It must be ensured that the used Filtration assemblies with little effort even under high loads cause for their cleaning.

The device according to the invention, the sieve element, is independent Claim 1 defined. A drainage trough with such a Siebelement is defined in claim 5, a street cleaning vehicle with such a sieve element in claim 6, a sewer cleaning vehicle with such a screen element in claim 9. Especially advantageous features emerge from the dependent claims.

Figur 1 :

Prinzip der Vorrichtung zur Wasserrückgewinnung für Strassenkehrfahrzeuge;

Figur 2a:

Seitenansicht des Abscheidesiebes;

Figur 2b:

Frontansicht des Abscheidesiebes gemäss Figur 2a aus der Richtung des Pfeiles A;

Figur 2c:

Detailansicht des Abscheidesiebes gemäss dem Ausschnitt B aus Figur 2a, und

Figur 3 :

Prinzip der Vorrichtung zur Wasserrückgewinnung für Kanalreinigungsfahrzeuge.

The invention is explained in more detail below, in specific embodiments, with reference to the attached schematic drawings. Show:

Figure 1:

Principle of the device for water recovery for road sweeping vehicles;

Figure 2a:

Side view of the separating sieve;

Figure 2b:

Front view of the separating sieve according to Figure 2a from the direction of arrow A;

Figure 2c:

Detailed view of the separating sieve according to section B of Figure 2a, and

Figure 3:

Principle of the device for water recovery for sewer cleaning vehicles.

The relevant part of the road sweeper here consists of the dirt hopper 1, which is on the vehicle frame 2 is mounted and around a container axis 3 for Emptying process can be tilted, opening it an emptying flap 5 is provided on the rear drop side 4 is that pivot up about the flap axis of rotation 6 leaves. A suction pipe 7 projects into the dirt hopper 1, whose outer end is designed as a suction mouth 8, with the the water-sprayed debris from the road surface 9 in the dirt hopper 1 is sucked. The suction on the suction mouth 8 is generated by a high-performance blower 10 which over a suction channel 11 with the interior of the dirt hopper 1 communicates. In the transition from suction channel 11 to the dirt hopper 1 is a coarse screen 12 in the cover plate 13 of the Waste container 1 arranged in addition to the function as a container wall also serves as a baffle on which the sucked in Debris its essential share of kinetic Depletes energy. The coarse sieve 12 has to prevent the task that pieces of debris whirling around in the dirt hopper 1 do not get out again via the suction channel 11. The output of the high-performance blower 10 goes into the free Atmosphere and can also be wholly or partly to support of the sweeping process steered onto the road surface 9 become. Upstream of the dirt hopper 1 is a by a screen wall 14 divided trickle 15. The Sieve wall 14 is a vertical partition with several superimposed lines (see Fig. 2b) of Giant breakthroughs 17 by aligned on these lines Shielding elements 18 are shielded.

In the bottom 19 of the trickle shaft 15 is a drain opening 20 with an attached drain connector 21, which opens into a settling tank 22 at the pool inlet 23. The settling basin 22 has a conical shape at the bottom narrowing bottom plate 24 with a cone angle α of about 60 ° to 150 °. The bottom plate 24 has in the depression 25 a drain member 26, e.g. Tap, flap or slide open. A vertical wall is attached to the funnel-like base plate 24 27 on, between the base plate 24 and the vertical wall 27 a container corner 28 is formed. From the pool inlet 23 extends almost into the corner of the container 28 Guide element 29, which has the shape of a cover-like insert plate owns or is made up of segments. That to the vertical central axis of the settling basin 22 and downward hood-like, conically widening guide element 29 spans at a guide element opening angle (γ), which is approximately in the range of 60 ° to 120 °.

Above the guide element 29 and near the vertical wall 27 attaches a transfer pipe 30 to the Service water tank 31 and leads to the consumer. In the course of the transfer pipe 30 there are two T-branches 33, 34 provided, immediately behind the sedimentation basin 22 in the transfer pipe 30, a solenoid valve 35 is positioned. The further course of the transfer pipe 30 leads to the first T-branch 33. From here runs a vertical line branch as suction line 36 in the Lowering nozzle 37 of the domestic water tank 31. At the bottom of the lowering nozzle 37 is a drain member 32, e.g. a rooster or one Flap, built-in. In the course of the suction line is the solenoid valve 38 arranged. Extends from the T-junction 33 the transfer pipe 30 to the second T-branch 34, the between the two T-branches 33, 34 Domestic water pump 39 is located. At the second T junction 34 branches a vertical branch as a supply line 40 to the domestic water tank 31 from. The solenoid valve 41 is in the feed line 40 Installed. Also extends from the second T-junction 34 a consumer feed line 42, also in this one solenoid valve 43 is seated. From a distribution cross 44 lead individual lines 45 to 47 to the different Consumers 48 to 50. To close or open the Individual lines 45 to 47 to consumers 48 to 50 is an actuator in each individual line, e.g. a ball valve 51 provided up to 53.

The structure of FIGS. 2a to 2c is shown in FIG Screen wall 14 emerges, the most appropriate geometric Relationships are described with reference to Figure 2c. The partitioning of the trickle shaft 15 from the dirt hopper 1 Screen wall 14 extends between the bottom 19 and the cover plate 13. The screen wall 14 consists of the screen plate 54 and the shielding elements 18, which in the screen plate 54 systematically provided trickle openings 17 assigned are. Perforated lines 17 come as perforations 17 or longitudinal slots. For specific applications, e.g. when separating sand or fine-grained Debris, it can be advantageous to use the trickle openings 17 cover with a mesh screen (not shown). As It could also prove expedient, the giant breakthroughs 17 near the bottom 19 initially very small hold and then with increasing height towards the Cover plate 13, to enlarge, because the finer debris 56 by the shaking movements when the sweeper is traveling rather compacted towards the bottom 19, while the coarser ones Collect solids on top of Kehrgutberg 57.

A shielding element is located above each perforated line 55 18 arranged, the sloping downward, canopy-like, shields the perforated line 55 from the dirt hopper 1. The accumulated debris 56 fills the space below the shielding element 18 not completely off; it remains irregular trickle channel 58. When debris is being accumulated 56 the sweepings are retained against the screen wall 14 to the extent than the immediate run-up to the breakthroughs 17 remains free, meaning that sweepings 56 are hardly in front of you can accumulate the breakthroughs 17. The choice of materials for the sieve plate 54 and the shielding elements 18 according to economic criteria and the required strength happen. The sieve plate 54 and the shielding elements 18 must withstand the dynamic pressure of the sweeping mountain 57, the shielding elements 18 also have sufficient stability if, for example, larger stones hit.

• Die Abschirmelementenlänge l als Distanz vom Ansatz 59 des Abschirmelementes 18 an der Siebplatte 54 bis zur Aussenkante 60 des Abschirmelementes.
• Der Anstellwinkel β als vom Abschirmelement 18 und der Siebplatte 54 eingeschlossener Winkel.
• Der Abschirmelementenabstand a als Distanz vom Ansatz 59 eines Abschirmelementes 18 an der Siebplatte 54 zum Ansatz 59 des nächsten Abschirmelementes 18 an der Siebplatte 54.
• Der Durchbruchdurchmesser d als Durchmesser oder adäquates Mass für die Grösse der Rieseldurchbrüche 17.
• Die Durchbruchtieflage t als Distanz vom Ansatz 59 eines Abschirmelementes 18 an der Siebplatte 54 bis zur Unterkante 61 der unterhalb dieses Abschirmelementes in der Siebplatte 54 befindlichen Lochzeile 55.
• Das Projektionsmass p als Ankathetenabschnitt auf der Siebplatte 54 zum Anstellwinkel β und bezüglich der Abschirmelementenlänge l bzw. als Projektion der Abschirmelementenlänge l auf die Siebplatte 54.
• Der Bodenabstand b als senkrechte Distanz von der Aussenkante 60 des untersten Abschirmelementes 18 zum Boden 19.

So that the trickle channels 58 form correctly and the dewatering of the debris 56 runs optimally, the geometric dimensions of the screen wall 14 must adhere to certain relationships. These relevant dimensions are:

• The shielding element length l as a distance from the shoulder 59 of the shielding element 18 on the screen plate 54 to the outer edge 60 of the shielding element.
• The angle of attack β as the angle enclosed by the shielding element 18 and the sieve plate 54.
• The shielding element distance a as the distance from the shoulder 59 of a shielding element 18 on the sieve plate 54 to the shoulder 59 of the next shielding element 18 on the sieve plate 54.
• The breakthrough diameter d as the diameter or an adequate measure for the size of the trickle breakthroughs 17.
• The breakthrough depth t as the distance from the shoulder 59 of a shielding element 18 on the sieve plate 54 to the lower edge 61 of the perforated line 55 located below this shielding element in the sieve plate 54.
• The projection dimension p as a section of the catheter on the sieve plate 54 at the angle of incidence β and with respect to the shielding element length l or as a projection of the shielding element length l onto the sieve plate 54.
• The ground clearance b as a vertical distance from the outer edge 60 of the lowermost shielding element 18 to the floor 19.

l ≈ 150 mm bis 300 mm

β ≈ 30° bis 60°

a ≈ 1,2 l

d ≈ 5 mm bis 10 mm

t ≈ 1 / 3 P

b ≈ 20 mm.

The following values were found to be advantageous in extensive test series:

l ≈ 150 mm to 300 mm

β ≈ 30 ° to 60 °

a ≈ 1.2 l

d ≈ 5 mm to 10 mm

t ≈ 1/3 P

b ≈ 20 mm.

The dimensioning of the breakthrough deep position t is crucially dependent on the length of the shielding element l and the angle of incidence β, in which case it was assumed that the sieve plate 54 is perpendicular to the floor 19, which serves for an appropriate use of space with regard to the dirt hopper 1 and the trickle shaft 15.

Now the device according to Figures 1 to 2c described in function. At a beginning street cleaning tour one assumes that the domestic water tank 31 is filled while the settling tank 22 is empty. All drain members 26 and 32, all solenoid valves, are closed 35, 38, 41 and 43, the ball valves 51 to 53 as well the emptying flap 5. The sweeping process with water spray - assuming the consumer 49 is to be switched on - started, the high-performance blower 10 and Domestic water pump 39 activated; at the same time you open the Solenoid valves 38 and 43 and the ball valve 52. Likewise the corresponding ones, not shown here, are switched on Sweeping units. From the street surface 9 is the suction mouth 8 the moistened waste is picked up and over the Suction pipe 7 drawn into the interior of the dirt hopper 1. During the cleaning tour there will be 1 form a debris hill 57, with debris 56 before the Screen wall 14 accumulates. Through the repellent shielding elements 18 the room will be directly under the shielding elements and not completely with debris 56 near the sieve plate 54 fill in, but there will remain free channels 58. The debris 56 itself acts as the first filter layer for the escaping water, which is in the trickle channels 58 accumulates and through the trickle openings 17 in the sieve plate 54 runs into the trickle shaft 15. Coarse debris parts are retained by the screen plate 54 while fine-grained material is partially washed away. The end The water flowing out of the Kehrgutberg 57 reaches the Trickle shaft 15 through the drain opening 20, over the drain port 21 in the pool inlet 23 and finally in the sedimentation tank 22. The fine-grained debris washed away 56 settles in the depression 25 of the settling basin 22 as Solid layer 62, while there is a relative clean water layer 63 forms.

About contactors, not shown, in the settling tank 22 - triggered at high water level - and / or in Service water tank 31 - triggered when the water level is low - the operator receives a switchover signal. Now it is about recovered water from the settling tank 22 into the process water tank 31 to transfer. It finds a basic one Change in the switching position of the solenoid valves 35, 38, 41 and 43 instead. Now the solenoid valves 35 and 41 are opened and the solenoid valves 38 and 43 closed. In order to the domestic water pump 39 sucks the water layer 63 from the Sedimentation basin 22 and conveys the water via the supply line 40 in the domestic water tank 31. During pumping the sweeping process is briefly interrupted. Is pumping around is ended, it is again in the previous operating state hazards. This way, much of the over the consumers sprayed 48 to 50 water several times in the Cycle managed and used. Of course, the Device also with two separate pumps and corresponding Valve arrangement are operated so that no switching or no sweeping interruptions are necessary.

The conical base plate has a special function 24 in the settling basin 22. This favors the settling process, i.e. the precipitation of the fine-grained, washed away Sweepings. Essential for funding of the settling are also the guide elements 29. Due to the arrangement of the guide elements 29 become the accumulated solids in the settling basin 22 during the vibrations caused by the Driving movements and the flowing current calms down. Further prevents the shielding effect of the guide elements 29, that of the suction pipe of the transfer pipes 30 too Substance is also sucked out of the solid layer 62.

Has the depression 25 in the settling tank 22 very much filled the solid layer, this can be opened by opening the Drain element 26 drained off at a designated place become. The domestic water tank also has a cleaning function 31 a drain member 32 at the bottom of the countersink 37. For special applications could still be provided in Use a fine filter in the course of the feed line 40. Consequently would find the first filtration stage on the screen wall 14, on the settling tank 22 the second filtration stage and on the eventual Fine filter the third filtration stage instead.

Figure 3 shows that the invention - i.e. the screen wall 114 and the settling tank 122 - also in a sewer cleaning vehicle 100 can be used. The following Exposure is therefore no longer based on the structure and function of the structural units essential to the invention, but only their basic arrangement in a sewer cleaning vehicle 100 described.

Located on the sewer cleaning vehicle 100 a process water tank 131, in the bottom of which a suction line 136 flows into. A domestic water pump 139 conveys the water from the tank 131 via a consumer feed line 142 to the Consumer 150, here a spray nozzle in one to be cleaned Channel 109. The consumer supply line 142 is from the hose reel 170 designed as a hose. With the spray nozzle a jet of water is poured into the channel 109 and thus settled Mud washed up. This water-solid mixture is sucked off from a suction nozzle 108 and via the suction pipe 107 passed into the washware container 101. The washware container 101 is of a through a sieve wall 114 Rieselkammer 115 divided. Collects in the cleaning container 101 the items to be cleaned 156, with a concentrate layer 157 settles down while one less concentrated thin sludge layer 171 forms over it.

The concentrate and thin sludge layer 157, 171 jam in front of the sieve wall 114, which also consists of a Sieve plate 154 with trickle openings arranged in lines 155 117 and these canopy-like shielding elements 118 exists. The essentially water thin sludge layer 171 deposited on top becomes without a filtration process through the trickle openings 117 in drain the screen wall 114 in the direction of the trickle chamber 115. In contrast, the viscous concentrate layer Accumulate 157 on screen wall 114, the shielding elements 118 the concentrate does not reach the trickle openings 117 bide; here, too, form immediately before the breakthroughs 117 trickle channels 158. In this way the Concentrate layer 157 drained without the screen plate 154 added soon.

Is a certain water level in the trickle chamber 115 exceeded, e.g. by a swimmer 172 a sewage pump 173 can be switched on from the trickle chamber 115 through a connecting pipe 121 Pump dirty water into settling tank 122. In the settling tank 122, as already described for FIG. 1, the second filtration stage takes place. In the depression 125 of the sedimentation basin 122 a solid layer 162 settles out while a layer of water 163 forms over it. In the sedimentation basin 122 extends into the water layer 163 - arranged over the guide elements 129 - a transfer pipe 130. By means of a clarified water pump 174, the clarified water from Sedimentation basin 122 pumped into the process water tank 131. if necessary can in the course of the transfer pipe 130 a rewindable filter 176 can be installed. Via a downpipe 175, the bottom - at the sink 125 - of the sedimentation basin 122 and in the washware container 101 leads, can be formed in the settling basin 122 Solid layer 162 can be drained cyclically.

If the washware container 101 is excessive Concentrate 157 is filled, the container is on usual Emptied, e.g. by means of a pneumatic extension piston or by tipping over. For the arrangement of the Screen wall 114 and settling tank 122 on the sewer cleaning vehicle 100 are other options than previously shown here. The screen wall 114 could also do this be provided in the front part of the vehicle and that Sedimentation basin 122 need not be in or near the process water tank 131 be placed. Thanks to the arrangement, it is now too possible, with relatively simple means, the rinse water in Sewer cleaning vehicles 100 repeatedly in the circuit to use. The withdrawn water is sufficient Purity processed so that the affected Conveying and distribution units for reuse of the clarified water.

The inventive sieve element can be advantageous can also be used in drainage troughs. This will at least one outer wall of the drainage trough through the Screen wall formed, their nature and mode of action already described with reference to Figures 1, 2a and 3 has been. It is also conceivable that all four walls of the drainage trough to be designed entirely or partially as a screen wall. It should be sufficient for certain applications be one or more horizontal or vertical Provide wall strips in the form of the sieve wall. Also one window-like arrangement is conceivable.

Claims (11)

1. Screening element for drainage troughs or for apparatuses for recovering water in road-cleaning and sewer-cleaning vehicles, comprising a screening plate (54,154) which is arranged essentially vertically in the installed state and has a multiplicity of systematically arranged trickling through-passages (17,117), which are provided in horizontally running lines (55,155), spaced apart parallel to one other and arranged one above the other, and which are shielded by shielding elements (18,118), characterized in that the shielding elements (18,118) are arranged such that they project rectilinearly and obliquely in the downward direction from the screening plate (54,154) in a canopy-like manner at a setting angle (β), which is in the range of from 30° to 60°, and shield the trickling through-passages in a canopy-like manner, as a result of which drainage material or material which is to be cleaned (56,156) is unable to accumulate directly in front of the trickling through-passages, but rather a trickling channel forms in the wedge-shaped corner between the screening plate and the shielding element (18,118) which also remains if the level of the material which is to be cleaned is located above the respective trickling channel.
2. Screening element according to Claim 1, characterized in that the trickling through-passages (17,117) in the screening plate are configured as bores or slots, it being possible for the trickling through-passages to be configured such that they increase in size in the upward direction starting from the lines (55,155) in the vicinity of the base (19).
3. Screening element according to either of Claims 1 and 2, characterized in that the shielding elements (18,118) are protected against bending and deformation by reinforcements.
4. Screening element according to one of the preceding claims, characterized in that the trickling through-passages (17,117) are covered by a screening mesh.
5. Drainage trough with a base and a variety of outer walls, characterized in that at least one complete outer wall or a horizontal or vertical wall strip or a trough corner or, in a window-like arrangement, a screening element according to one of the preceding claims is provided.
6. Road-cleaning vehicle having a screening element according to one of Claims 1 to 4 as a screening wall (14) for providing a partition between a sweepings container (1) and a trickling shaft (15), and having a settling basin (22) to which the water which has been separated off by means of the screening wall (14) is fed for further cleaning purposes, it being the case that the settling basin (22) has a base plate (24), which narrows in the downward direction at a cone angle (α), and an adjoining vertical wall (27), these together forming a container corner (28), and it being the case that an obliquely downwardly oriented directing element (29) is installed from the basin inflow (23) virtually as far as the container corner (28), said directing element being mounted in a hood-like manner at a directing-element opening angle (γ).
7. Road-cleaning vehicle according to Claim 6, characterized in that the conical base plate (24) forms a depression (25), at the lowermost position of which a discharge element (26) is provided, it being the case that a layer of solids (62) and, above the latter, a layer of water (63) form at the bottom of the settling basin (22), and it being the case that the water is drawn off from the settling basin (22) by a transfer pipe (30), the connecting piece of the latter starting above the directing element (29), in the vicinity of the vertical wall (27) and the container corner (28), and leading into a service-water tank (31), and is directed into the service-water tank (31), and thus withdrawn from the sweepings (56) and recirculated to consuming units (48,49,50) of the road-cleaning vehicle.
8. Road-cleaning vehicle according to either of Claims 6 or 7, characterized in that the cone angle (α) is between 60° and 150° and the directing element (29) is formed in a single piece in the manner of a cover or comprises a plurality of sheet-like segments, the directing-element opening angle (γ) being between 60° and 120°.
9. Sewer-cleaning vehicle having a screening element according to one of the Claims 1 to 4 as a screening wall for providing a partition between a cleaning container (1010) and a trickling chamber (115), and having a settling basin (122) to which the water which has been separated off by means of the screening wall (14) is fed for further cleaning purposes, it being the case that the settling basin (22) has a base plate (24), which narrows in the downward direction at a cone angle (α), and an adjoining vertical wall (27), these together forming a container corner (28), and it being the case that an obliquely downwardly oriented directing element (129) is installed from the basin inflow (23) virtually as far as the container corner (28), said directing element being mounted in a hood-like manner at a directing-element opening angle (γ).
10. Sewer-cleaning vehicle according to Claim 9, characterized in that the conical base plate (24) forms a depression (125), at the lowermost position of which a discharge element (26) is provided, it being the case that a layer of solids (162) and, above the latter, a layer of water (163) form at the bottom of the settling basin (122), and it being the case that the water is drawn off from the settling basin (122) by a transfer pipe (130), the connecting piece of the latter starting above the directing element (29), in the vicinity of the vertical wall (27) and the container corner (28), and leading into a service-water tank (131), and is directed into the service-water tank (131) and thus withdrawn from the material which is to be cleaned (156) and recirculated to a consuming unit (150) of the sewer-cleaning vehicle.
11. Sewer-cleaning vehicle according to either of Claims 9 and 10, characterized in that the cone angle (α) is between 60° and 150° and the directing element (129) is formed in a single piece in the manner of a cover or comprises a plurality of sheet-like segments, the directing-element opening angle (γ) being between 60° and 120°.

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