EP0629749B1 - Apparatus for cleaning of sewer conduits - Google Patents

Abstract

The invention relates to an apparatus for cleaning sewer ducts by flushing by means of water, in the case of which provision is made for a flushing apparatus which is equipped with a cleaning nozzle (6) and is supplied with high pressure water by a high pressure water pump, and for a suction/pressure unit which acts as a water jet pump and is terminated by a suction head (7). The motive water for the water jet pump is produced by a second liquid pump. Both the cleaning nozzle (6) and the suction head (7) are fed by a common high pressure water pump (2), it being possible for the high pressure water jet which is produced by the high pressure water pump (2) to be divided up by a three-way valve (4) into a liquid jet which is fed to the flushing head (6) and a liquid jet which acts as motive water for the suction head (7), designed as an ejector. A water treatment apparatus (13) exhibits a coarse filter, a hydrocyclone and a fine filter. <IMAGE>

Description

The invention relates to a device for cleaning sewers by rinsing by means of water in which rinsing devices and suction devices are used.

Various devices and vehicles for cleaning channels are known in which the required rinsing water is carried in a water tank and is fed to the rinsing device by means of a high-pressure pump. Furthermore, a suction unit is provided which ensures that dirty water and the solids more or less dissolved by the rinsing water are sucked in. This dirty water is returned to the tank in sufficient purity via upstream filter devices. In this way, a constant liquid circulation is ensured and the facility largely covers its process water requirements from the water supply it carries with it. This is a largely automomotive facility.

According to DE-AS 26 48 851 and DE-OS 33 23 719 a sludge suction vehicle is known in which the flushing devices are supplied with flushing water by a high-pressure pump via high-pressure water hoses, which is removed from the water tank. A second pump unit is used to extract the dirty water. There is one on the cleaning vehicle for conveying the sludge attached, suction water jet pump provided, the motive water flow is generated by a low pressure water pump.

According to DE-AS 23 15 656 a sewer cleaning vehicle is known which has a water tank, a flushing device and a high-pressure pump for conveying flushing water from the water tank to the flushing device and also a suction unit, a suction line and a suction basket for sucking in dirty water. The dirty water is passed through a filter device and converted into process water that is fed to the tank.

From US-A-3,013,665 a device for suctioning water and sludge from a retention basin is known. The device is mounted on a motor vehicle. It has a tank with a flap, which is divided into several sedimentation tanks by several plates. The last pool near the flap is used to hold the sludge, while the first pool is said to contain the reasonably purified water. A pump with its own drive motor is arranged next to the tank, which sucks the water out of the tank and conveys it to a suction / pressure unit via a three-way valve. The suction / pressure unit is introduced into the retention basin during operation and i conveys the sludge-water mixture from this via a pressure line into the tank. A hose that runs over a hose drum is used as the pressure line. The three-way valve also serves to connect the pressure side of the pump in a second position to a drain line which runs along under the tank when a further suction line is introduced into the retention basin via a further valve arrangement in order to draw off the upper liquid layer therefrom. The water pumped from the retention basin in this way is simply drained onto the street through the free end of the drain line. The three-way valve therefore differentiates between two operating positions, namely once the water is directed from the tank to the suction / pressure unit to convey a water-sludge mixture and in another position for sucking off the water layer above the mud and discharging it onto the road.

DE-C-686 519 discloses a tank car for cleaning sink boxes which works by means of a suction hose and which consists of a work vehicle and a trailer wagon separate therefrom. The work vehicle contains a feed tank, which has approximately the volume of a sink box to be emptied, while the trailer wagon carries a sludge container. The feed tank is firmly mounted on the work vehicle together with a three-way valve and other components, and the sludge tank is also not removable from the trailer truck, but can only be swiveled up on it for the purpose of emptying.

The mentioned and other sewer cleaning devices working on the same principle have common disadvantages.

Separate pump units are used both for the implementation of the flushing process by commissioning the flushing device and for the suction of the dirty water by means of a corresponding suction unit, which leads to expensive and complex solutions.

In addition, the efficiency of the pump unit used to draw in the dirty water depends on the suction height to be overcome. The further the suction head moves away from the pump unit, the greater the suction losses, which can only be compensated for by an appropriate design of the suction pump. The impairment of the suction height can lead to the suction flow being cut off and thus to cavitation and thus damage to the pump set. In addition, the maximum delivery head in suction systems when using a vacuum pump is physically limited to around 8 m, taking into account the atmospheric pressure and the specific weight of the pumped medium.

The invention has for its object a cost-effective device for cleaning sewers with high operational reliability and to create a large conveying capacity which is arranged in a mobile manner on a suitable vehicle and has a largely low-loss water circuit for rinsing and suctioning off mud, sand, faeces and the like. is guaranteed and is also suitable to convey the sludge up to a sludge tank over a height of at least 15 m.

In this case, the heavily polluted water in the sludge tank sucked in by the jet suction device should be cleaned in such a way that the high-pressure water pump can be continuously supplied with water of sufficient quality from the water tank.

The device according to the claim serves to achieve this object.

A feature of the invention is that the device consists of two modules designed as containers, of which one container is a vehicle attachment and the other container is a trailer attachment, the vehicle attachment for receiving the container for the process water, all units that the Rinse the sewer with process water, suction the dirty water and process the dirty water to process water, and the trailer attachment is provided to hold the sludge tank. The functional connection between the vehicle attachment on the one hand and the trailer attachment on the other hand can be established by means of quick-connect hoses.

In view of the large rinsing / suction capacity (1000 l / min at 210 bar) required for the described sewer cleaning process, filtered water with a relatively high degree of purity must be made available to ensure as little wear as possible. The permissible size of the dirt particles is approx. 100 µm.

Due to the high suction power of the jet vacuum cleaner, the proportion of suspended matter and whirled up residues in the sludge tank is relatively high.

It is already known to use hydrocyclones with different pre-filtering (perforated plates, chains, etc.). However, their main disadvantage is that only solids with a significantly greater specific mass than water can be separated. This means that suspended matter cannot be separated. This is disadvantageous because, especially with high-performance pumps, considerable premature wear can occur.

For this reason, various downstream fine filter stages have already been used. These are mostly drum filters with scrapers. The main disadvantages of these fine filters are that, due to the surface tension of the water, only gap widths of up to about 300 µm can be achieved. Narrow, but elongated dirt particles can get through the filter gaps. And finally, mechanical wipers can only remove particles from the filter surface, but not remove stubborn dirt from the filter gaps.

Backwash filters as fine filters have proven themselves in many areas of industrial cleaning. The use in the context of water treatment on sewer cleaning vehicles is known from DE-C-27 36 587 .

Figur 1

eine schematische Ansicht des Ausführungsbeispiels; und

Figur 2

Einzelheiten der Wasseraufbereitungseinrichtung von Figur 1.

The invention is explained in more detail below with reference to figures; show it:

Figure 1

a schematic view of the embodiment; and

Figure 2

Details of the water treatment device of Figure 1.

In the figures, the same parts are provided with the same reference symbols throughout. Details of component "13" from FIG. 1 are designated in FIG. 2 by the reference symbols "131-139".

According to FIG. 1, the device according to the invention is expediently assigned to two mutually independent containers. One of the two containers is designed as a vehicle attachment 14, the other container as a trailer attachment 15. With suitable lifting means, both the vehicle attachment 14 and the trailer attachment 15 can be parked at the place of use and put into operation together.

The preferred embodiment provides for the vehicle attachment 14 to be equipped with a filled water tank 1, from which domestic water is pumped with a water pressure of approximately 210 bar by a high-pressure pump 2 driven by a diesel unit 3. In the pressure side of the high-pressure pump 2 there is a three-way valve 4 which divides the liquid flow and continues it in two lines. Part of the high-pressure water is fed to a cleaning nozzle 6 via a hose. A driven hose reel 5 ensures that the hose and thus the cleaning nozzle 6 are guided in the sewer.

After the cleaning nozzle 6, the suction head 7, which is designed as a jet suction device or ejector, is arranged, with which the sludge suction is carried out. The suction head 7 is connected to the second part of the high-pressure water flow supplied by the high-pressure pump 2, which acts as a motive water flow. The driving water flow introduced into the suction head 7 and accelerated by nozzles generates a negative pressure in the suction head 7, which sucks in the impurities dissolved by the cleaning nozzle 6 with rinsing water and presses at high pressure through the suction hose 8 into the mud container 9 located on the trailer attachment 15. There If the ejector is located at the bottom of the suction hose 8, both the suction properties and the pressure properties of the jet suction device can be used, which for this reason is also referred to as a “suction / pressure unit. This means that significantly higher delivery heights can be achieved compared to the purely suction processes .

The process water is separated from the sludge by a perforated plate 10 and collected in a collecting trough 11. The recovered service water is sucked off with a dirty water pump 12 and filtered to a very high degree of purity in a multi-stage water treatment device 13 and returned to the water tank 1.

The division of the device according to the invention into two containers which can be handled independently of one another, of which one container, in addition to the water container 1 for the used water, all units which serve to rinse the sewer with used water, to extract the dirty water and to process the dirty water into used water, includes and the other container accommodates the sludge container 9 has the advantage that a simple exchange of filled sludge containers 9 with empty sludge containers 9 can be carried out and the device has to accept correspondingly short downtimes. The necessary hose connections can be made easily using quick-release couplings.

FIG. 2 shows details of the water treatment device 13 which is arranged between the sludge tank 9 and the water tank 1. In FIG. 2, the sludge tank 9 is shown reversed from the illustration in FIG. 1, ie the sludge conveyed by the jet suction device via the suction hose 8 enters the sludge tank 9 on the right, in which residues settle on the perforated plate 10, while dirty water from the drip pan 11 is pumped out by the dirty water pump 12 from the left part of the sludge tank 9. The dirty water pump 12 conveys the dirty water pre-filtered through the perforated plate 10 via the line 17 into a hydrocyclone 131, in which by vortex formation Solid components are separated from the process water, the specific mass of which is significantly higher than that of water. The solids sink down and are returned to the sludge tank 9 via a process water return line 138. The service water freed from the heavier solid particles flows out of the hydrocyclone 131 at the top and is fed from above into a buffer tank 132, which serves to collect service water bursts and to continuously supply service water to a downstream backwash filter. For this purpose, the process water is sucked out of the buffer tank 132 by a sludge pump 133 and fed to a last filter stage, namely the backwash filter 134. This filter stage ensures that the dirt particle size in the water tank 1 does not exceed the size of 100 microns. The filter effect is achieved by a filter fabric applied to the circumference of a drum. With increasing contamination of the filter surface, the pressure difference between the filter inlet and the filter outlet of the backwash filter 134 increases, which is detected by a sensor 135 and passed on to a controller 16.

If the filter contamination level and accordingly the differential pressure measured by the differential pressure sensor 135 exceed a preset value, the filter is backwashed and the surface of the filter fabric is thus freed of dirt particles.

For the backwashing, cleaned water is sucked out of the water tank 1 by a centrifugal pump 136 and fed with a pressure of about 6 bar to a cleaning arm 139, which is arranged in the backwashing filter 134 and rinses the filter fabric. For this purpose, the cleaning arm 139 has a nozzle, with which rinses the rinsing water from the filter fabric in the opposite direction to the normal filter flow. In this way, even stubborn dirt particles are released from the filter fabric and, together with the rinsing water, are flushed back to the sludge tank 9 via the return line 138.

During the backflushing, the cleaning arm 139 is continuously moved in a circular movement along the filter cylinder surface so that the entire tissue surface can be cleaned during one revolution. The process water filtering in the backwash filter 134 is not interrupted during the entire flushing phase.

Finally, a level sensor 137 in the water tank 1 ensures that the level in the water tank 1 is measured and the measurement result is transmitted to the controller 16. The water treatment is accordingly regulated with the fill level sensor 137.

• Grobfilter (10)
• Hydrozyklon (131)
• Feinfilter (134).

The water treatment according to the invention is thus divided into three stages:

• Coarse filter (10)
• Hydrocyclone (131)
• Fine filter (134).

The continuous determination of the degree of contamination of the backwash filter 134 makes it possible to carry out the backwash only when this is actually necessary. As a result, the not inconsiderable amount of water required for backwashing can be adapted to the fluctuating degree of pollution of the water to be cleaned. This represents a decisive advantage in view of the large amount of water required for the jet suction process.

Claims (1)

1. A device for cleaning sewer conduits by rinsing with water and removal of sludge by suction, having:

   a) a removable vehicle fixture (14) comprising:

   a1) a water tank (1);

   a2) a high-pressure pump (2) which is connected to the water tank (1);

   a3) a diesel unit (3) which drives the high-pressure pump (2);

   a4) a three-way valve (4) which is disposed on the output side of the high-pressure pump (2) and divides the stream of liquid and conveys it to a cleaning nozzle (6), which can be introduced into the sewer conduit, and/or to a suction/output unit which can also be introduced into the sewer conduit, acts as a water jet pump and ends with a suction basket (7), with the part of the stream of liquid conveyed to the unit serving as motive water for the suction basket (7) constructed as a jet suction device.

   a5) a hose reel (5) for coiling and guiding the hose leading from the three-way valve (4) to the cleaning nozzle (6);

   a6) a water treatment apparatus (13), which is connected to the water tank (1) and filters the water to a very high degree of purity;

   b) a removable trailer fixture (15) comprising:

   b1) a sludge tank (9) with collecting vat (11) and coarse filter apparatus (10), which is connected via a delivery hose (8) to the suction/output unit (7);

   b2) a waste water pump (12), which conveys the service water from the collecting vat (11) of the sludge tank (9) via a pipe (17) into the water treatment apparatus (13); and

   b3) rapid action couplings, which produce the hose connections from the trailer fixture (15) to the vehicle fixture (14) and to the suction/output unit (7) without any problems.

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