Pump station arrangement and method for removing harmful fluids from wastewater

Patent metadata

Field	Value
Publication number	US-11235995-B2
Application number	US-201616062254-A
Country	US
Kind code	B2
Filing date	Dec 12, 2016
Priority date	Dec 16, 2015
Publication date	Feb 1, 2022
Grant date	Feb 1, 2022

Abstract

A pump station arrangement for removing harmful fluids from wastewater and a method for removing harmful fluids from wastewater in such a pump station arrangement. The pump station arrangement includes a pre-chamber, a pump sump, a recirculation channel extending from the pump sump to the pre-chamber, and a gas sensor arranged in the pump sump and configured to measure the content of harmful fluids in the form of gas in the pump sump. The pump station arrangement is configured to recirculate the wastewater via the recirculation channel from the pump sump to the pre-chamber if the measured content of harmful fluids in the form of gas in the pump sump exceed a predetermined value. Also disclosed is.

First claim

The invention claimed is:

1. A pump station arrangement in a wastewater transportation system, wherein the pump station arrangement comprises:
a pre-chamber having an inlet for influent wastewater connected to one or more households and an outlet,
a pump sump having an outlet connected to a sewage system or to a sewage treatment plant for effluent wastewater, and an inlet that is in fluid communication with the outlet of the pre-chamber by an intermediate conduit such that wastewater is transported from the pre-chamber to the pump sump under the influence of gravity through the intermediate conduit,
at least one pump connected to the outlet of the pump sump and to a recirculation channel extending from the pump sump to the pre-chamber, and
a gas sensor arranged in the pump sump and configured to measure the content of hydrogen sulphide (H 2 S) in the form of gas in the pump sump,
wherein the pump station arrangement is configured to remove hydrogen sulphide (H 2 S) in gaseous phase or in liquid phase from the wastewater by transformation of the H2S by oxidation to an oxidized sulphuric species by recirculating wastewater via the recirculation channel from the pump sump to the pre-chamber if the measured content of H 2 S in the form of gas in the pump sump exceeds a predetermined value.

2. The pump station arrangement according to claim 1 , wherein the inlet of the pre-chamber is arranged in a vertical direction at a level above said outlet of the pre-chamber.

3. The pump station arrangement according to claim 1 , wherein the recirculation channel has an opening in the pre-chamber that is arranged in a vertical direction at a level above the outlet of the pre-chamber.

4. The pump station arrangement according to claim 1 , wherein during normal operation, the pump station arrangement is configured to keep the outlet of the pump sump closed and the recirculation channel open if the measured content of hydrogen sulphide (H 2 S) in the form of gas in the pump sump exceeds said predetermined value.

5. The pump station arrangement according to claim 1 , wherein the pre-chamber is hermetically sealed from the surrounding atmosphere.

6. The pump station arrangement according to claim 1 , wherein the inlet of the pump sump is arranged in the vertical direction at a level below the outlet of the pre-chamber.

7. The pump station arrangement according to claim 1 , wherein the gas sensor is configured to measure content of hydrogen sulphide (H 2 S) in the form of gas in the pump sump in parts per million (ppm).

8. The pump station arrangement according to claim 1 , wherein the predetermined value is either a predetermined Short Term Exposure Limit (STEL) or a predetermined Time Weighted Average (TWA) limit.

9. The pump station arrangement according to claim 1 , wherein the pump station arrangement comprises a second gas sensor arranged in the pre-chamber and configured to measure the content of hydrogen sulphide (H 2 S) in the form of gas in the pre-chamber.

10. The pump station arrangement according to claim 1 , wherein the pump station arrangement comprises a gas pump configured to transport gas from the pump sump to the pre-chamber.

11. The pump station arrangement according to claim 10 further comprising an aerator at the bottom of the pre-chamber that is configured to be supplied with pressurized gas from said gas pump.

12. The pump station arrangement according to claim 10 , wherein the gas pump is located in the pump sump.

13. The pump station arrangement according to claim 1 , wherein a distance between the pump sump and the pre-chamber is in a range of greater than or equal to 20 meters to less than or equal to 30 meters.

14. The pump station arrangement of claim 2 , wherein the pre-chamber comprises an air volume and the recirculation channel extends from the pump sump to an opening in the pre-chamber located in the air volume.

15. The pump station arrangement of claim 14 , further comprising a distribution plate arranged directly under said inlet of the pre-chamber and in a vertical direction at a level above said outlet of the pre-chamber.

16. The pump station arrangement of claim 15 , wherein the inlet for the influent wastewater is arranged so that the influent wastewater flows or splashes down onto the upper surface of the distribution plate from said inlet of the pre-chamber.

17. The pump station arrangement of claim 11 , wherein said gas pump is connected to said aerator via an air hose, and said air hose is arranged in a casing tube extending from the pre-chamber to the pump sump.

18. The pump station arrangement of claim 10 , further comprising a suction hose extending from the pump sump to the gas pump.

19. The pump station arrangement of claim 1 , wherein the inlet is configured to receive influent wastewater from a plurality of households.

20. The pump station arrangement of claim 10 , wherein the at least one pump consists of a single pump located in the pump sump and connected to both the outlet of the pump sump and to the recirculation channel, with a controllable valve positioned between the pump and respective connections to the outlet and to the recirculation channel to direct flow from the pump.

21. The pump station arrangement of claim 10 , wherein the at least one pump comprises a first pump connected to the outlet of the pump sump and a second pump connected to the recirculation channel.

Assignees

• Xylem Ip Man S A R I
• Xylem Europe Gmbh

Inventors

• Strandberg Tore
• Hedmark Per

Classifications

• F04B23/02 Primary

  having reservoirs · CPC title

• F04B51/00 Primary

  Testing machines, pumps, or pumping installations · CPC title

• C02F2301/046

  Recirculation with an external loop · CPC title

• F04B15/00

  Pumps adapted to handle specific fluids, e.g. by selection of specific materials for pumps or pump parts · CPC title

• C02F2101/101

  Sulfur compounds · CPC title