EP0387759B1 - Sewer cleaning vehicle - Google Patents

Abstract

The sewer cleaning vehicle has an intermediate compartment (22) connected between those for slurry and water, and an additional front compartment (24) connected between it and the slurry compartment (14). Three pipes (32,66,76) connect the compartments, which are set in a row in a common tank (10), with the water compartment (82) in two parts at the tank sides. The first and third pipes each contain a low-pressure pump (42,78) below the tank, and the second filter (44) is in the front compartment above the bottom, the first pipe discharging above the periphery of its drum (48). The second pipe leads from the filter to the intermediate compartment, and a suction pipe (58) extends from the bottom of the front compartment below the filter back to the top of the slurry compartment.

Description

The invention relates to a sewer cleaning vehicle with a sludge compartment to be closed by a pivotable tailgate and with a service water compartment, both of which are connected to one another in terms of pipes. In the sludge water compartment there is a first filter for coarse screening of the sludge water present in this compartment and drawn in from outside the vehicle through a sludge hose. In this line there is also a second filter in the form of a rotating sieve drum provided with wipers. A high-pressure pump is installed in the other line leading away from the service water compartment.

With the sludge hose lowered into a sewer or the like, the sludge water present there can be sucked off into the sludge water compartment, which is under vacuum. This sludge water is pumped into another process water compartment, where it flows through several filter systems. The process water is therefore relatively clean in relation to the sludge water, so that it cannot be disposed of, but can be reused. This service water can be sent into a flushing hose with a high-pressure pump, which is provided with a nozzle head and is also lowered into the sewer to be cleaned. With the help of the pressure jet emerging from the nozzle head, the solid sludge present in the sewer is loosened and drawn to the sewer shaft so that it can be sucked off through the sludge hose.

Such a sewer cleaning vehicle is known from DE-OS 3140200. Mud water compartment and process water compartment are available in this vehicle in a common tank, one behind the other. The common partition between the two compartments is designed in the form of a piston which is longitudinally displaceable in the boiler, so that by displacing this piston the one compartment can be made smaller in volume and the other compartment correspondingly larger. In the process water compartment there is a rotating sieve drum provided with wipers for fine screening, over the lateral surface of which the feed line leading from the mud water compartment into the process water compartment ends. The purified water accumulating inside this sieve drum is removed from the process water compartment and led to the high-pressure pump. In front of the inflow opening of the line leading away from the sludge water compartment and leading to the process water compartment, an intermediate wall designed in the form of a coarse sieve is installed in the sludge water compartment, through which the mouth opening is to be kept free from the sludge and other contaminants sinking into the sludge compartment.

From the high-pressure pump, water can only be drawn from the service water compartment through the sieve drum. The delivery rate depends on the performance of this filter. An additional removal directly from the service water compartment is not provided and also does not make sense, since the dirt stripped from the outer surface of the screen drum by its wipers is present in the water accumulated in the service water compartment. The water in the process water compartment does not form a real water reservoir for charging the high pressure pump.

Starting from this prior art, the invention is based on the object of specifying a sewer cleaning vehicle of the type mentioned at the outset which does not have the disadvantages known from the prior art and which can be used optimally.

This invention is given by the features of the main claim. The sewer cleaning vehicle known from the prior art is characterized in particular by the fact that in the common tank container the sludge water compartment has an intermediate compartment and a further front compartment, in each case one behind the other. The actual process water compartment is formed by two additional tanks on the side of this tank container. The second filter, which is designed in the form of a rotating sieve drum, is arranged in the front compartment, above the bottom of the tank container. The cleaned water leaving this filter is introduced into the intermediate compartment, while the dirt accumulated by the filtration accumulates in the bottom area of this front compartment and cannot flow into the intermediate compartment. From the bottom area of this front compartment, a suction line also leads back into the sludge water compartment, so that the accumulated dirt can be returned to the sludge water compartment and can no longer be dragged along in the line system to the process water compartment. The water from the intermediate compartment is then pumped through a separate pipe into the process water tanks. Service water can therefore be drawn from the tanks by the high-pressure pump, regardless of whether the rotating sieve drum is also in operation at this moment or not. In the sewer cleaning vehicle according to the invention, the process of recycling the accumulated sludge water is thus spatially and functionally separated from the process of extracting the used water by the various water compartments present. Due to their separate arrangement, the process water tanks never come along Sludge water in contact so that it can be cleaned easily. This has the advantage that the initial supply of the sewer cleaning vehicle with drinking water into these tanks is possible without great effort.

In order to prevent the filter in the front compartment from being flooded by the dirty water accumulated in the bottom area of this compartment, an upper float switch is provided in such a way that the pump, which is present in the line leading to the front compartment, is switched off when the maximum water level within the front compartment is correspondingly high becomes. In addition, a further float switch is available, which closes the suction line leading into the sludge water compartment with a corresponding minimum level of dirty water in the front compartment. If there is a vacuum in the sludge water compartment, a vacuum cannot therefore also be created in the front compartment through the suction line.

In order to improve the quality of the hot water, according to a further feature of the invention, a further filter is installed in the line leading from the intermediate compartment to the hot water tanks. This filter acts as a fine filter and removes dirt particles that are larger than 0.08 mm from the dirty water. These dirt particles can still pass through the upstream sieve drum, since only dirt particles up to about 0.3 mm in size can be sieved out of the same. This fine filter located in the line to the service water tanks is automatically monitored with regard to its effective filter area. This monitoring controls the cleaning process of the filter surface without interfering with the recovery process. As a result, service water for the high-pressure pump can be drawn from service water tanks regardless of whether this fine filter is in operation.

According to a further feature of the invention, that in the mud compartment before the mouth is that leading to the front compartment The existing coarse screen is not formed down to the floor, but is attached to an intermediate floor. This largely prevents clogging of this coarse screen, since sludge and other larger contaminants can settle below it in the bottom area of the sludge water compartment. The screen surface of this coarse screen remains practically fully effective. This only changes when the volume of sludge and dirt settled in the bottom of this sludge water compartment is so large that it is higher than the intermediate floor. Before this happens, however, the water in the mud water compartment has risen so high that the vehicle is fully loaded and can no longer work.

According to a further feature of the invention, between the sludge water compartment and the intermediate compartment there is the piston-like configuration of the common partition wall, which is known per se from the prior art. The arrangement of the piston between these two compartments has no effect on the usable volume available in the service water tanks. If a large percentage of sludge is sucked in through the sludge hose, the sludge water compartment can be chosen to be relatively large and the intermediate compartment can be selected to be correspondingly small without the reprocessing process being adversely affected thereby; the amount of hot water available there is still available from the hot water tanks. Conversely, if the percentage of solid dirt is relatively low, the sludge water compartment can be chosen to be small and the intermediate compartment can be chosen to be large. This also has no influence on the amount of water accumulating in the process water tanks and available there.

So that the water to be drawn off from the sludge water compartment or from the intermediate compartment is as sludge-free as possible, the corresponding line openings are attached to the mechanical Schwinner displays in these compartments. The openings are therefore desirable far above of the corresponding compartment floor.

Further advantages and refinements of the invention can be found in the features further specified in the claims and in the exemplary embodiment below.

Fig. 1

einen schematischen Längsschnitt durch die verschiedenen Wasserabteile eines erfindungsgemäßen Kanalreinigungsfahrzeuges mit schematisierter Darstellung der verschiedenen Leitungsverbindungen zwischen den Abteilen und

Fig. 2

eine schematisierte Darstellung des in der Vorderkammer vorhandenen Siebtrommel-Filters.

The invention is described and explained in more detail below with reference to the embodiment shown in the drawing. Show it:

Fig. 1

a schematic longitudinal section through the different water compartments of a sewer cleaning vehicle according to the invention with a schematic representation of the different line connections between the compartments and

Fig. 2

a schematic representation of the filter drum present in the front chamber.

A tank container 10 is attached to a sewer cleaning vehicle, not shown in detail. This tank container 10 has a circular cylindrical shape in cross section. Its rear end with respect to the vehicle is designed in the form of a rear plate 12 which can be folded upwards by a hinge arrangement at the top and can thus be folded away from the tank container 10.

The tailgate 12 is the rear end boundary of a mud water compartment 14, which is delimited by an end wall 16 on its opposite end side facing away from the driver's cab. This end wall 16 is part of a piston arrangement 18 which at this point closes the tank container 10 in cross section. Due to a circumferential sealing profile 20, the mud water compartment 14 is one separated by the piston assembly 18 intermediate compartment 22.

In front of this intermediate compartment 22, a front compartment 24 is still present within the tank container 10. The front compartment 24 is delimited on its front side by the end face 26 of the tank container 10. In the tank container 10, the sludge water compartment 14, the intermediate compartment 22 and the front compartment 24 are thus arranged one behind the other.

A suction hose 28 protrudes into the sludge water compartment 14 from above, through which sludge water can be sucked into the sludge water compartment 14 from outside. The suction takes place due to the negative pressure generated in the sludge water compartment 14.

An intermediate floor 30 is fastened to the tailgate 12 and is connected to the remaining wall of the tank container 10 lying above the intermediate floor 30 via wall regions designed as a coarse sieve 31. The coarse screen wall areas 31 can be folded up by a hinge 33.

In the tailgate 12, above the intermediate floor 30, a first line 32 opens into the mud water compartment 14 from the outside, which ends inside the mud water compartment 14 in a flexible piece of hose 34. The mouth 36 of this flexible hose piece 34, which is provided at its free end, is attached to a mechanical float indicator 38. This ensures that the mouth opening 36 is always in the area of the water level 40 present in the mud water compartment 14.

The line 32 leads to a low-pressure pump 42 below the tank container 10 and from there to the front compartment 24 of the tank container 10. The line 32 opens into this front compartment 24 and ends there in the area of a second pre-filter, a sieve drum filter 44 Sieve drum pending, fed through line 32 Water 46 flows through the outer surface 47 of the sieve drum 48 from the outside inwards and from there below through the outer surface, the surface of the outer surface 47 being covered with dirt particles 50 which are larger than 0.3 mm in diameter. When the sieve drum 48 rotates, which is represented by the arrow 52, these dirt particles 50 are removed again from the lateral surface 47 by a scraper 54. These dirt particles 50 fall into the bottom area of the front compartment 24 and form a more or less dense layer of dirty water 56 there.

A suction line 58 projects into the dirty water layer 56 at one end. This suction line 58 leads from above into the sludge water compartment 14.

A lower float switch 60 and an upper float switch 62 are provided in the front compartment. The lower float switch 60 controls a shut-off valve 64 installed in the suction line, which it closes when the dirty water layer 56 has an extremely low water level. The upper float switch 62 switches off the low pressure pump 42 present in the first line 32 when the water level of the dirty water layer 56 has reached a maximum upper water level. This maximum upper water level is still below the sieve drum filter 44, so that this filter 44 cannot be impaired in its cleaning action by the dirty water layer 56.

The water cleaned by the sieve drum filter 44 flows in a free flow via a second line 66 through the partition wall 68 between the intermediate compartment and the front compartment into the intermediate compartment 22.

In the intermediate compartment 22 there are floating bodies 72 in a guide box (not shown) for protection against surge movements, to which the mouth opening of a flexible piece of hose 74 is fastened. This piece of tubing 74 opens at one end into a third line 76, in which a second low-pressure pump 78 is installed and which leads to a fine filter 80. In this fine filter, the water sucked out of the intermediate compartment 22 through the flexible hose piece is further cleaned down to a dirt particle size of 0.08 mm in diameter. The cleaned water emerging from the filter is further guided by means of this low-pressure pump 78 into separate service water tanks 82 arranged laterally next to the tank container 10.

The dirt particles accumulating in the fine filter 80 are pumped back into this compartment 14 via a return line 84 which opens into the sludge water compartment 14 from above.

The fine filter 80 has an integrated pressure difference control which, for example, visually indicates the degree of contamination when there is a differential pressure between the filter inlet and filter outlet and initiates a cleaning process for this filter, the recovery process not being interrupted.

A line 88 leads from each of the two service water tanks 82 to a high-pressure pump (not shown in more detail). This high-pressure pump supplies a rinsing hose that can be lowered into the sewer to be cleaned with process water.

From this high-pressure pump, a branch line 90 leads back to the screen drum filter 44, so that the service water 92 present in the service water tank 82 can also be used to clean the screen drum 48. This is done by nozzles 93, which flush the screen drum 48 from the inside out.

In order to avoid turbulence when sucking water out of the service water tanks 82, a so-called vortex breaker 96 is located in the area of the inlet opening of the respective line 88 available.

Lines 98 and 100 each lead from above into the two process water tanks 82 and the intermediate compartment 22, each of which can be connected to a drinking water supply source 102. There is a fine filter in line 98, so that even when filling with fresh water e.g. Contamination from a hydrant cannot get into the tanks and from there to the high pressure pump. Drinking water can thus be filled both in the service water tanks 82 and in the intermediate compartment 22.

When cleaning with fresh water, e.g. the intermediate chamber is completely filled with tap water at least once.

Valves are also present in the various lines, so that the corresponding lines can be blocked or opened in accordance with the respective mode of operation of the sewer cleaning vehicle.

Claims (13)

1. Sewer cleaning vehicle having

― a sludge liquor compartment, which can be closed by a tail-gate which can be swivelled away from said sludge liquor compartment,

― a service water compartment,

― a first pipe connection, consisting of a plurality of pipes, between the sludge liquor compartment and the service water compartment,

― a first filter inside the sludge liquor compartment for the coarse filtering of the sludge liquor which is present in this compartment and is taken in from outside the vehicle through a sludge hose,

― a second filter in the form of a revolving screen, provided with scrapers, in the first pipe connection,

― a high-pressure pump in another pipe leading away from the service water compartment, characterised in that

― there is an intermediate compartment (22) connected by piping between the sludge liquor compartment (14) and the service water compartment (82),

― there is an additional front compartment (24) connected by piping between this intermediate compartment (22) and the sludge liquor compartment (14),

― a first pipe (32) being present between the sludge liquor compartment (14) and the front compartment (24),

― a second pipe (66) being present between the front compartment (24) and the intermediate compartment (22),

― a third pipe (76) being present between the intermediate compartment (22) and the service water compartment (82),

― the sludge liquor compartment (14), the intermediate compartment (22) and the front compartment (24) being present, located in series one behind the other, in a common tank (10),

― the service water compartment being formed by two tanks (82) arranged in each case at the sides of the tank,

― a low-pressure pump (42, 78) being present in each case in the first pipe (32) and third pipe (76) at a level below the tank (10),

― the second filter (44) being arranged in the front compartment (24) above its bottom,

- - the first pipe (32) opening out above the outer surface (47) of the revolving screen (48) of this filter (44),

- - the second pipe (66) leading from this second filter (44) into the intermediate compartment (22),

- - a suction pipe (58) leading from the lower inside region (56) of the front compartment (24) from below the second filter (44) back into the sludge liquor compartment (14) and opening out there from above into said sludge liquor compartment.

2. Vehicle according to Claim 1, characterised in that
an upper float switch (62) is mounted in the front compartment (24) in such a way that, at a maximum water level corresponding to this float switch (62) inside the front compartment (24), which is still located below the second filter (44), the first pump (42) is switched on and the suction pipe (58) is opened.

3. Vehicle according to Claim 2, characterised in that
a lower float switch (60) is mounted in the front compartment (24) in such a way that, at a minimum water level corresponding to this float switch (60) inside the front compartment (24) the suction pipe (58), which is still immersed at this water level and leads to the sludge liquor compartment (14), can be closed (64).

4. Vehicle according to Claim 1, characterised in that
there is a further filter (80) in the third pipe (16), said filter (80) being connected additionally to a return pipe (84) which opens out into the upper region of the sludge liquor compartment (14) and through which the dirt accumulating at this filter (80) can be returned into the sludge liquor compartment (14).

5. Vehicle according to Claim 1, characterised in that

― this filter (80) has an integrated pressure differential control which initiates a cleaning operation in the case of a differential pressure between the filter entrance and the filter exit,

― due to the differential pressure between the return pipe (84) and the clean side of the filter, the particles of dirt are pulled off the filter and fed to the return pipe (84) through a rotating suction nozzle driven by a hydromotor, which return pipe opens out into the upper region of the sludge liquor container,

― this return operation is supported by the negative pressure in the sludge liquor container,

― this return operation operates fully automatically and the recovery process is not interrupted because, in terms of volume, only a small portion passes back to the sludge container via the return pipe.

6. Vehicle according to Claim 1, characterised in that

― there is partially an intermediate bottom (30) in the sludge liquor compartment (14) having side walls (31) which adjoin upwards and are partially constructed as a screen,

― the orifice (36) of the first pipe (32) is present above this intermediate bottom (30),

― the wall region, constructed as a screen, can be swivelled up by a hinge (33).

7. Vehicle according to Claim 1, characterised in that
the common partition, which is present between the sludge liquor compartment (14) and the intermediate compartment (22), is constructed as a piston (18) which can be displaced through the tank (10), with the result that, by displacing this piston (18) a corresponding reduction in the intermediate compartment (22) corresponds to an enlargement of the sludge liquor compartment (14).

8. Vehicle according to Claim 7, characterised in that,
with the tail-gate (12) swivelled away, the piston (18) can be passed completely through the sludge liquor compartment (14), with the result that the sludge present in this compartment can be pushed out by the piston (18) when the tail-gate (12) has been swivelled away.

9. Vehicle according to Claim 1, characterised in that
a pipe (98, 100) projects from the two tanks (82) and the intermediate compartment (22) at the top in each case for connection to a supply (102) of fresh water.

10. Vehicle according to Claim 1, characterised in that
the orifice (36) of the first pipe (32) projecting into the sludge liquor compartment (14) and the orifice of the third pipe (74, 76) opening out into the intermediate compartment are each attached to mechanical floating indicators (38, 72).

11. Vehicle according to Claim 1 or 9, characterised in that
there is in the intermediate compartment (22) a mechanical floating indicator (69), by means of which the pump (78) present in the third pipe (76) can be switched off at an extremely low water level and the pump (42) present in the first pipe (32) can be switched on at an extremely high water level.

12. Vehicle according to Claim 1, characterised in that
there is in the tanks (82) a mechanical floating indicator (99), by means of which the third pipe (76) can be closed at an extremely high water level.

13. Vehicle according to Claim 1, characterised in that
the tanks (82) are connected by piping.

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