FR2467922A1 - METHOD AND DEVICE FOR AUTOMATIC CIRCULATION IN PUMPED WATER PUMPING STATIONS - Google Patents

Abstract

The invention relates to a method and a device for automatic circulation in pumping stations of wastewater. In a pumping station 1 using a submersible pump 4 there is provided, on output 3 of the station or output 5 of the pump, an electrically or hydrostatically controlled valve 7 which, during a predetermined time interval, opens a connection between outlets 3 or 5 and the pumping station to circulate the pumped fluid and thus mix the layers of mud. The invention applies to wastewater pumping stations.

Description

The invention relates to a method and a device ensuring a circulation

  in pumping stations that are part of a network

Municipal Egotit.

  In a pumping station, which also serves as a storage chamber for wastewater, sludge layers occur at the bottom as well as at the surface of the water. These layers are more common for

  low water velocity and for large pumping intervals.

  There is a microbiological degradation of the sludge whose speed depends on the temperature. When oxygen has been used, a fermentation process takes place, producing H2S (hydrogen sulfide), CH4 (methane), etc. Acid is also produced which results in a lower pH value. Hydrogen sulphide emits an odor and is also toxic. Fatalities occurred during maintenance work in pumping stations filled

hydrogen sulphide.

  Hydrogen sulphide produces, in combination with oxygen, sulfuric acid whose pH has a value close to 1. This means

  significant corrosion damage to parts that are

  above the surface of the water, such as electrical equipment and

  ture. In addition, the piping system corrodes when pumping

  the water. Concrete pipes can collapse due to the corro-

and block the link.

  Methane can easily ignite, causing explosions.

  To avoid this, it is necessary to provide costly installations

explosion.

  The methods used so far to prevent the production of sludge have given poor results. This means in practice that the pumping stations must be rinsed with clean water at regular intervals so that the layers of mud break and become

mix with water.

  This method of getting rid of this septic mud is however very expensive because the mud becomes septic in four to six

  hours in northern Europe and in one to three hours in a tropical climate.

  The invention relates to a method and devices for circulating and mixing water in pumping stations at

  temporary pumping in recycling using the pumps available.

in the station.

  The invention will be better understood and other features

  will appear with the following description and accompanying drawings

  o: - Figure I shows a pumping station comprising a valve according to the invention; FIG. 2 represents a pumping station where the valve is arranged differently;

  FIG. 3 represents a valve comprising a special type of arrangement

control system; and

  FIG. 4 represents another embodiment of the valve according to the invention;

  tion. In the figures, the number 1 identifies a pumping station with its inlet 2 and its outlet 3. The number 4 identifies a submerged pump with an outlet 5 connected to a discharge connection 6 of the outlet pipe 3. The number 7 landmark a valve comprising a device

  control 8, an output (diffuser) 9 and an output line or

  return number 10. Figures 11 and 12 identify water levels.

  The number 13 identifies a valve piston, the number 14 a scroll membrane, the number 15 a level tank, the number 16 a partition wall, the number 17 a return spring, the number 18 a needle valve, the figure 19 a valve stem, the number 20 a pipe, the number 21 a connecting pipe, the number 22 a

  valve shutter and the number 23 a lever.

  In FIG. 1, a pumping station 1, with conventional equipment,

  tional device, comprises a device according to the invention. According to the pre-

  pump 4 is started when the water level reaches the mark 11. The pump then rotates until level 12 is reached and starts again when the level is reached again. As a result, there is no real mixing of the water in the pumping station, which increases the risks of water formation.

layers of mud.

  According to the invention, a valve 7 is connected to the outlet 5 of the pump 4. When the pump starts, this valve is open, which means that the pumped fluid flows back into the pumping stations and

  creates a strong current and mix, which homogenizes the pumped fluid.

  After a while, the valve closes and the fluid is pumped through the outlet 3, in the usual way, until level 12 is reached. The valve then opens again and remains in

  this position until the next start of the pump.

  Figure 2 shows another connection of the valve according to the invention. When the valve 7 is open, the pumped fluid flows into the pumping station through the pipe 10 which ends near the bottom of the station, where the sludge layers occur. To any other

  point of view, this device works in the same way as the

according to Figure 1.

  The valves described here are electrically controlled. Figure 3 shows a hydrostatic control valve that operates

as follows.

  When the pump starts, the valve is opened, leaving an open connection between the pump outlet and the pump station, so that a reflux described above is obtained. The piston 13 is

  is then in a high position under the influence of spring 17. The

  sion prevailing in line 20, connected to the outlet of the pump

  push down the membrane to unwind 14. The speed of this movement

  downward, that is to say the closing time, is determined by a device of the type needle valve o collaborate a leakage hole in the partition wall and the needle 18. It can be done

  vary the closing speed by narrowing the needle.

  When the piston 13 has reached its low position, the linkage

  its 21 closes and stays there as long as the pump is working.

  When the pump stops, the pressure in the line 21 decreases and the spring 17 returns the unwinding membrane 14 and the piston 13 to their original position thus allowing a new cycle myping. In the embodiment shown in FIG. 4, the valve is designed as a two-way valve with a rotating shutter disposed in the outlet 3. When the pump starts, the outlet is closed by the shutter 22, while the orifice towards the return line 10 is open. The fluid then flows through the pipe 9 rotating diffuser. After a period of time, the drive unit 8, controlled by a timed relay, rotates the shutter 22 so that the orifice in the direction of the return line closes while

  the orifice towards the outlet opens.

  According to the invention, a method and arrangements are thus provided.

  automatic control of pumping and reflux (circulation) in a pumping station. The invention brings obvious advantages

  concerning the improvement of the environment at pumping stations

  page and reducing the risk of failures caused by

sludge.

  The devices described above are only possible embodiments. Several other solutions are possible in

the limits of the invention.

Claims (7)

  A method of automatic circulation in sewage pumping stations containing one or more pumping units, characterized in that the outlet (3) of the pumping station (1) or the outlet (5) of the pumping unit (4) in the station comprises a valve (7) which, during a predetermined time interval (intervals of time), opens a connection between the outlets (3) or (5) and the pumping station (1), this which results in a reflux of everything or part of the pumped fluid.   2. Method according to claim 1, characterized in that the   connection is always open when the pump starts.   3. Device for implementing the method according to one   claims 1 or 2, characterized in that it comprises a valve (7)   electrically controlled disposed in the outlet (5) of the pump (4).   4. Device for implementing the method according to one   claims 1 or 2, characterized in that it comprises a valve (7)   with an electric control arranged in the outlet pipe (3) of the pump, which valve can be arranged above the maximum level of the water (11), this valve (7) being connected to a pipe (10) which   ends near the bottom of the pumping station (1).   5. Device for implementing the method according to one   claims 1 or 2, characterized in that it comprises a driving   link (21) at the outlet (5) of the pump (4), which pipe is connected to an adjustable connection with an outlet (9) and to a cylinder which has a diaphragm (14) influenced, in the direction opening of   the adjustable connection by a spring (17) and in the closing direction   the pressure in the outlet of the pump (5), control means (15, 16, 17, 18, 19) being provided for controlling the time interval required before the pressure   the pump does not outperform the spring force enough for the connection its adjustable closes.   6.Tevice according to any one of claims 3 to 5,   characterized in that the outlet (9) of the valve (7) can rotate in the pumping station (1).   7. Device according to any one of claims 3 to 5,   characterized in that the valve (7) is a two-way gate valve turning point.