DE20007500U1 - Sewage lifting station - Google Patents

Description

LONG PA.' -

INDUSTRIAL PROPERTY LAW OFFICE ■ PATENT ATTORNEY OFFICE

32425 MINDEN · GERMANY

Attorney file: 464.202

Wolf-Dieter Börner
Wachtelweg 18

32457 Porta Westfalica

Wastewater lifting station

The invention relates to a sewage lifting plant, preferably for domestic and property sewage, which flows into a collecting tank of the lifting plant via an inlet line and an inlet opening and is conveyed into an outgoing pressure pipeline with the aid of compressed air.

Known lifting systems for house and property drainage work primarily with centrifugal pumps or other sewage pumps,

which transport the wastewater via pressure pipelines into the public sewer system or a connected treatment plant. In pressure drainage via small-dimensioned pipelines, wastewater pumps with external cutting tools are used to break down the impurities and thick materials contained in the wastewater into easily flowable material. This requires powerful electric motors for the pump and cutting unit drives, e.g. in the form of powerful, explosion-proof three-phase motors.

In order to save the considerable costs for the installation and maintenance of the pump drives, lifting systems have been developed that can be operated pneumatically and for this purpose require a compressed air compressor and an open/close valve in the inlet line. The present invention deals with the type of pneumatically operated sewage lifting system.

Known pneumatic lifting systems are controlled in such a way that the open/close valve in the inlet line to the collecting tank and also the vent line of the collecting tank are closed when the maximum filling level of the waste water in the collecting tank is reached, whereupon the collecting tank is pressed by a compressed air compressor via

a compressed air line is pressurized with compressed air and the waste water is transported into the pressure pipe via the outlet opening near the bottom in the collecting tank, i.e. is pressed into the pressure pipe.

For cost reasons, the impurities and thick matter in the wastewater are not crushed, which in turn means that not only the inlet pipe and the inlet opening into the collecting tank, but also the outlet opening from the collecting tank and the pressure pipe must have a sufficiently large cross-section.

This also applies to the on/off slide valve in the supply line, which is better suited to shutting off larger pipelines than a valve, but (compared to a valve) generally causes greater resistance to movement. As a result, the positive drive of the slide valve always requires a high external energy supply, regardless of whether the positive drive of the slide valve is electromechanical, hydraulic or pneumatic.

»&iacgr;♦ Il .■»

♦ « * * *■ ii .

i,ii nt

In the case of pneumatic lifting systems, it is advisable to operate the slide valve pneumatically, but this cannot be carried out without metallic components on the drive side and, due to the sometimes (also chemically) aggressive atmosphere in a wastewater lifting system, requires an increased frequency of repairs and maintenance.

The object of the invention is to reduce the frequency of repairs and maintenance in pneumatically operated sewage lifting systems and to show a way how a lifting system of this type with all essential functional components can be manufactured entirely from plastic and at the same time the energy balance of such systems can be optimized.

This object is achieved according to claim 1 in that the inlet opening is positioned in the upper ceiling of the collecting tank and is surrounded on the inside of the ceiling by a vertical pipe which is hermetically connected to the upper ceiling and whose lower outlet end is arranged at a distance from the bottom of the collecting tank, wherein the outlet opening of the collecting tank near the bottom is formed by the lower inlet end of a riser pipe which opens into the pressure pipeline and whose rise height is greater than the height position of the inlet opening in the collecting tank with the proviso that

in ti i-i

the lower inlet end of the riser pipe is positioned approximately at the same level as the lower outlet end of the vertical pipe, and that a floating ball is arranged freely floating in the vertical pipe, which seals the inlet opening when the waste water is at its maximum fill level, and whose outer diameter is dimensioned in relation to the inner diameter of the vertical pipe such that it leaves a sufficient inlet cross-section between the floating ball and the vertical pipe when the waste water is at a level lower than the maximum fill level.

According to claim 2, both the vertical pipe and the riser pipe are each installed from above in the ceiling of the collecting tank by means of a flange cover and can be removed upwards from the collecting tank for cleaning purposes and that the collecting tank forms the entire lower part of an underground installation shaft.

According to claim 3, it is provided that all functional components of the system are made of plastic, namely the shaft itself with the collecting container integrated at the bottom and (on the inlet side) the inlet line, inlet opening and the vertical pipe with the floating ball as well as (on the outlet side) the riser pipe with the outgoing pressure pipe.

•♦ ·

Si m »&idigr; ,

• i * . . &idigr;

»it * i · &idigr;&iacgr; i »ti

The solution according to the invention has the decisive advantage that on the inlet side of the pneumatic lifting system, the closing and opening of the inlet opening is carried out completely automatically by the floating ball, without forced drive and without any external energy supply. The level of the waste water in the collecting tank alone is sufficient to close the inlet opening, and the pressurization of the collecting tank with compressed air during the pressurization phase, i.e. during the conveying process, is sufficient to keep the inlet opening closed.

This is achieved by the inventive combination of the floating ball with a vertical frame which is hermetically sealed against the upper ceiling of the collecting tank, which results in the fact that when the floating ball seals the inlet opening (which is always the case when the maximum filling level of the collecting tank is reached), the air space in the vertical pipe above the waste water level is hermetically sealed and the water column in the vertical pipe is held in the position of its maximum filling level (and consequently the inlet opening remains closed), provided and as long as the air pressure in the collecting tank, which prevails during the compressed air application phase, i.e. during the conveying process in the collecting tank, is of an order of magnitude

·« '·-· &idigr;&idigr; i it ·

which is greater than the water column pressure generated by the level of the water column at the lower outlet end of the vertical pipe.

In order to always and automatically achieve this order of magnitude of the air pressure in the collecting tank during the pressurization phase or during the conveying process, according to the teaching of the invention, there is a riser pipe inside the collecting tank, the riser height of which (measured above the lower inlet end of the riser pipe) is greater than the height position of the inlet opening in the collecting tank, the lower inlet end of the riser pipe being positioned approximately at the same level as the lower outlet end of the vertical pipe.

As a result, with the aforementioned simple means of a floating ball, a vertical pipe and a riser pipe (all of which can be easily manufactured from plastic), a functional sequence is achieved in a sewage lifting plant according to the invention that is completely free of externally controlled forced drives and thus completely free of components that are forced to move relative to one another. Disadvantageous signs of wear and necessary maintenance and repair work are practically no longer present in a plant according to the invention.

c**■·■ ·&ngr;

especially if all essential components of the system (shaft, collecting tank, pipes, floating ball, etc.) are made of a corrosion-proof and rot-proof plastic, such as PEHD or PVC.

To operate the sewage lifting system according to the invention, an electric air compressor with sufficient delivery pressure and sufficient air delivery capacity is required, which can be selected independently of the manufacturer and can be of a commercially available design. The supply and exhaust air in the collecting tank is most easily controlled using commercially available, electrically operated solenoid valves, which are installed in the vent line of the collecting tank and in the compressed air supply line in the collecting tank.

In principle, to operate such an all-plastic lifting system according to the invention, only an electrically operated solenoid valve in the vent line of the collecting tank and an electric air compressor are required, and the customer can choose whether these electrically wired components are to be installed in the underground installation shaft of the system or outside the shaft (e.g. in a weather-protected room in the house).

The air compressor and the solenoid valves are conveniently time-controlled in the

When the maximum wastewater level in the collecting tank is reached, the solenoid valve in the collecting tank's vent line is closed and the air compressor starts up. This operating state is maintained by a time relay until the collecting tank is emptied. The time required for this is to be statistically measured according to the air compressor's output and the back pressure.

An embodiment of the invention is described in more detail below with reference to the drawings.

Fig. 1 a vertical longitudinal section

by the system according to the invention with an underground installation shaft,

FiQ -, 2 a detail enlargement of the

Outlet end of the vertical pipe and the inlet end of the riser pipe according to Fig.

Fig. 1 shows an installation shaft 3 with a cover 4 and the shaft ventilation 5 as well as an integrated waste water collection tank 6, which forms the entire lower part of the shaft.

*i »V Si' · «· Vi-

- 10 -

The house and property wastewater flows into the collection tank 6 via the inlet pipe 7 and the inlet opening 8, from above through the flange cover 9 of the collection tank. The vertical pipe 10 is connected in an airtight manner to the underside of the flange cover. The outlet end 11 of the vertical pipe is located just before the bottom of the collection tank, i.e. at a distance from the bottom that is sufficient to allow the wastewater, including the impurities and thick matter contained in the wastewater, to flow into the collection tank.

In the vertical tube 10 there is the ■n"! floating ball 12 with an outer diameter that ensures that the floating ball

.;maximum filling level of the collecting container seals the inlet opening 8 and at the same time at a filling level lower than the maximum

,.JZ-W ₁ Isehen,-its outer diameter and the ,.inner diameter of the vertical pipe 10 leaves a sufficient inlet cross-section for the waste water.

If the maximum filling level of the waste water is reached in the collecting tank 6 and the inlet opening 8 is blocked by means of the floating ball 12, the vent line 13 of the collecting tank is closed by means of a solenoid valve (not shown), for example, which can be operated electrically, and the pressure

air supply line 14 is opened (if necessary again .. by means of an electrically operated solenoid valve), and at the same time a compressed air compressor starts up (not shown), which feeds compressed air into the collecting tank 6 via the compressed air supply line 14. The compressed air compressor as well as the aforementioned solenoid valves can usually be installed in the upper free space of the shaft, but can also be arranged outside the shaft, e.g. in a weather-protected room, since it is very easy to lay the relatively small-dimensioned ventilation line 13 and the compressed air supply line out of the shaft into an adjacent room.

.-.■._. -During the pressurization phase of the collecting tank 6, the waste water is conveyed via the lower inlet end 15 of the riser pipe 16 into the outgoing pressure pipe 17. Usually, the pressure pipe 17 contains a check valve 18 and (for maintenance purposes) also a ball shut-off valve 19.

The lower inlet end 15 of the riser pipe is positioned at approximately the same level as the lower outlet end 11 of the vertical pipe 10. This is to ensure that the falling wastewater level in the collecting tank at the end of the conveying process almost simultaneously reaches the inlet end

- 12 -

of the riser pipe and the outlet end of the vertical pipe, so that almost simultaneously the water column in the vertical pipe drops (so that the floating ball releases the inlet opening 18) and the conveying process is terminated.

Fig. 2 shows, on an enlarged scale, a particular detail of the embodiment of the lifting system according to Fig. 1. This detail is characterized in that the lower inlet end 15 of the riser pipe 16 is cut off at an angle in such a way that the falling wastewater level initially exposes a small outlet opening cross-section and then increasingly a larger outlet opening cross-section. Viewed in the direction of the falling wastewater level, the opening of the smaller outlet opening cross-section of the riser pipe begins by the dimension 20 before the opening of the lower outlet end 11 of the vertical pipe. This ensures that some compressed air (and thus oxygen) flows into the riser pipe and thus the pressure pipeline in advance in order to avoid a lack of oxygen in the wastewater and a resulting anaerobic state of the wastewater.

Claims (4)

1. Wastewater lifting station - preferably for domestic and property waste water, which flows into a collecting tank of the lifting station via an inlet pipe and an inlet opening and is pumped into an outgoing pressure pipe with the help of compressed air, - whereby the lifting system is controlled in such a way that the vent line of the collecting tank and an on/off valve in the inlet line are closed when the maximum filling level of the waste water in the collecting tank is reached, whereupon the collecting tank is pressurised with compressed air and the waste water is conveyed into the pressure pipeline via an outlet opening in the collecting tank close to the ground, characterized by - that the inlet opening ( 8 ) is positioned in the upper ceiling of the collecting container ( 6 ) and is surrounded on the inside of the ceiling by a vertical pipe ( 10 ) which is hermetically connected to the upper ceiling and whose lower outlet end ( 11 ) is arranged at a distance from the bottom of the collecting container, - that the outlet opening of the collecting tank near the ground is formed by the lower inlet end ( 15 ) of a riser pipe ( 16 ) which opens into the pressure pipe ( 17 ) and whose rise height is greater than the height position of the inlet opening ( 8 ) in the collecting tank, the lower inlet end of the riser pipe being positioned approximately at the same level as the lower outlet end of the vertical pipe, - and that a floating ball ( 12 ) is arranged in the vertical pipe ( 10 ) so as to float freely, which seals the inlet opening ( 8 ) when the waste water is at its maximum fill level and whose external diameter is dimensioned in relation to the internal diameter of the vertical pipe ( 10 ) such that it leaves a sufficient inlet cross-section between the floating ball and the vertical pipe when the waste water is at a fill level lower than the maximum fill level. 2. Lifting system according to claim 1, characterized in - that both the vertical pipe ( 10 ) and the riser pipe ( 16 ) are each installed from above in the ceiling of the collecting tank ( 6 ) by means of a flange cover and can be removed from the top of the collecting tank for cleaning purposes - and that the collecting tank forms the entire lower part of an underground installation shaft. 3. Lifting system according to claim 1 or 2, characterized in - that all functional components of the system are made of plastic, namely the shaft itself with the collecting tank and (on the inlet side) the inlet pipe, the inlet opening and the vertical pipe with the floating ball as well as (on the outlet side) the riser pipe with the outgoing pressure pipe. 4. Lifting system according to one of the preceding claims, characterized in that the lower inlet end ( 15 ) of the riser pipe ( 16 ) is cut off at an angle such that the falling wastewater level initially exposes a small outlet opening cross-section and then increasingly a larger outlet opening cross-section of the inlet end of the riser pipe.