SYSTEM AND METHOD FOR PURIFYING DOMESTIC WASTEWATER USING ONE CYCLE A DAY

Abstract

A system and method for purifying domestic sewage using 1 cycle per day, which reduces constructive complexities, energy demand and avoids the emission of hydrogen sulfide into the environment, the system comprising: a reactor comprising at least two air diffusers located at the bottom of the reactor; a sludge outlet duct and a clarified water outlet duct; a feed pipe connected at one end to a pump submerged inside a pumping chamber and at the other end to a wastewater inlet located at the bottom of the reactor; a programmable logic control; a valve arrangement consisting of four valves connected to a blower, each valve being connected to one of: the sludge outlet duct, the clarified water outlet duct, and the at least two diffusers.

Claims

1. A system for purifying domestic sewage using 1 cycle per day, which reduces construction complexities, energy demand and avoids the emission of hydrogen sulfide into the environment, comprising the system: a reactor (10) comprising at least two air diffusers (11) located at the bottom thereof; a sludge outlet duct (12) and a clarified water outlet duct (13); a feed pipe (23) connected at one end to a submerged pump (22) inside a pumping chamber (20) and at the other end to a waste water inlet (24) of the reactor (10); a programmable logic controller; wherein the wastewater inlet (24) is located at the bottom of the reactor and in that the system further comprises: a valve arrangement (30) consisting of four valves (31.1, 31.2, 31.3, 31.4) connected to a blower (40), each valve (31.1, 31.2, 31.3, 31.4) being connected to one of: the sludge outlet duct (12), the clarified water outlet duct (13) and one or two diffusers (11).

2. The system according to claim 1, wherein it further comprises an overflow pipe (50) having an opening (51) located at a minimum operating level of the reactor (10), said overflow pipe (50) being inclined.

3. The system according to claim 1, wherein one end of the overflow tube (50) which is inside the reactor (10) has an opening (51) in chamfer type cut.

4. The system according to claim 2, wherein the overflow tube (50) is inclined at 60°.

5. The system according to claim 1, wherein the sludge outlet pipe (12) empties into a septic tank.

6. The system according to claim 2, wherein the clarified water outlet conduit (13) and the overflow pipe (50) discharge to a disinfection plant.

7. The system according to claim 1, wherein the outlet conduits (12, 13) each consist of PVC pipes, with a first curved portion (12.1, 13.1) located at the top of the reactor and connected to a first vertical portion (12.2, 13.2) extending to the bottom of the reactor and connected to a second curved portion (12.3, 13.3), wherein said second curved portion is connected to a second vertical portion (12.4, 13.4) which extends to outside of the reactor (10), above a maximum water level.

8. The system according to claim 7, wherein said first curved portion (12.1, 13.1) has an open end (12.5, 13.5).

9. The system according to claim 1, wherein the pumping chamber (20) is connected to an inlet pipe (21) for domestic wastewater.

10. The system according to claim 1, wherein the connection between each valve (31.1, 31.2, 31.3, 31.4) and one of the sludge outlet pipe (12), the clarified water outlet pipe (13) and the at least two diffusers (11), is by means of hoses (32.1, 32.2, 32.3, 32.4).

11. The system according to claim 1, wherein the reactor (10) comprises two diffusers (11), each being connected to a valve (31.2, 31.3).

12. The system according to claim 1, wherein the reactor (10) comprises two pairs of diffusers (11), each pair being operated by a valve (31.3, 31.4).

13. A method for purifying domestic sewage in a system as defined in claim 1, using 1 cycle per day, wherein each cycle comprises the steps of: a) loading from a pumping chamber (20) and by means of a submerged pump (22), sewage water into a reactor (10) for a given time; b) actuating alternately for a given time two solenoid valves (31.3, 31.4) of a valve arrangement (30) connected to a blower (40), injecting air into at least two diffusers (11) located in the reactor (10); c) carrying out step a) until the pumping chamber (20) is completely emptied and from a given time carrying out step b) in parallel; d) turning off the submerged pump (22) and the solenoid valves (31.1, 31.2) for a given time; e) carrying out step b) for a given time; f) carrying out step d) for a given time; g) discharging clarified water from the reactor (10) by activating for a given time a solenoid valve (31.2) connected to a clarified water outlet line (13) located in the reactor (10); h) carrying out the step b) and g) alternately for a given time; i) discharging sludge from the reactor (10) activating a solenoid valve (31.1) connected to a sludge outlet conduit (12) located in the reactor (10) for a given time; j) carrying out in parallel and for a given time the steps a) and b); k) carrying out step b) for a given time; l) carrying out step c); m) carrying out steps b) and a) alternately for given times; n) definitively switching off the solenoid valves (31.1, 31.2, 31.3, 31.4) and the submerged pump (20).

14. The method according to claim 13, wherein the step i) comprises discharging sludge at a value of 1/25 of the height of the minimum operating level in the reactor (10).

15. The method according to claim 13, wherein it further comprises the steps of: o) detecting an overflow in the pumping chamber (20) or in the reactor (10); p) suspending the current cycle; q) discharging all the wastewater from the pumping chamber (20) into the reactor (10); r) carrying out step d); s) discharging water from the reactor through an overflow pipe (50) having an opening (51) located at a minimum operating level of the reactor (10); t) repeating steps q) to s) until no overflow is detected in the pumping chamber (20) or in the reactor; u) resuming the cycle in case it should be in progress.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0057] As part of the present invention, the following figures are presented which are representative of the present invention and, therefore, are not to be considered as limiting to the definition of the subject matter claimed.

[0058] FIG. 1 illustrates a general schematic of the components of the system of the present invention.

[0059] FIG. 2 illustrates a detailed schematic of the components of the sludge outlet and water outlet conduit.

[0060] FIG. 3 illustrates a detailed schematic of the valve equipment of the system and its connection to the various components.

[0061] FIGS. 4a to 4c illustrate modalities of the reactor of the invention for different wastewater treatment capacities.

DETAILED DESCRIPTION OF THE INVENTION

[0062] According to the preferred embodiment illustrated in FIG. 1, the system is formed by a reactor 10 consisting of a preferably cylindrical tank which inside and specifically at the bottom thereof, comprises at least two air diffusers 11.

[0063] To the interior of the reactor 10 there is also arranged a sludge outlet conduit 12 which, according to an embodiment of the invention, discharges the sludge towards a septic tank (not illustrated) and a clarified water outlet conduit 13 this discharging the clarified water to for example a disinfection plant (not illustrated and optional), which according to the exemplified embodiment are opposite and arranged close to the walls of the reactor 10. Preferably and as can be seen in more detail in FIG. 2, the outlet conduits each consist of PVC pipes, with a first curved portion (12.1, 13.1) located at the top of the reactor and connected to a first vertical portion (12.2, 13.2) extending to the bottom of the reactor and connected to a second curved portion (12.3, 13.3). Said second curved portion is connected to a second vertical portion (12.4, 13.4) which extends to the outside of the reactor, above a maximum water level.

[0064] The first curved portion (12.1, 13.1) has an open end (12.5, 13.5) which configures an inlet for the fluid flowing through each conduit. Furthermore, said curved portion is connected with a respective support (14, 15) configured to hold each conduit and keep it positioned inside the reactor, which preferably consists of a PVC pipe.

[0065] Referring back to FIG. 1, it is shown that the system comprises a pumping chamber 20 consisting of a small drum which receives the domestic wastewater by means of an inlet pipe 21 and which comprises in its interior a submerged pump 22 configured to pump the stored wastewater into the reactor 10, by means of a feed pipe 23. The feed pipe 23 flows into the bottom of the reactor 10, preferably into a wastewater inlet 24.

[0066] According to a preferred embodiment of the invention, the pumping chamber consists of a PVC drum with lid (sealed) and with a capacity of preferably 200 L.

[0067] As can be seen in FIG. 1, the system comprises a valve arrangement 30, consisting of 4 solenoid valves connected to a blower 40. Furthermore as illustrated in more detail in FIG. 2, a first valve 31.1 is connected by means of a first hose 32.1 to the sludge outlet conduit 12, preferably by means of a first starting collar 33.1.

[0068] A second valve 31.2 is connected via a second hose 32.2 to the clarified water outlet conduit 13, preferably via a second starting collar 33.2. A third valve 31.3 is connected by means of a third hose 32.3 to at least one diffuser 11, while a fourth valve 31.4 is connected by means of a fourth hose 32.4 to at least another diffuser 11.

[0069] According to the embodiment of the invention where four diffusers are used (see FIG. 4c), the third valve 31.3 is connected to a flow divider and then by means of two hoses to each of the diffusers 11 of the first pair of diffusers. Similarly, the fourth valve 31.4 is connected to a flow divider and then by means of two hoses to each of the diffusers 11 of the second pair of diffusers.

[0070] The size of the reactor 10 and the number of diffusers 11 will depend on the treatment capacity required by the system, for example according to the number of people living in the place where the plant will be installed. Accordingly, FIGS. 4a to 4c show three top views of the reactor 10 with preferred arrangements depending on the treatment capacity and whose characteristics are summarized in the table below:

TABLE-US-00001 Reactor's Reactor's height diameter No of FIG. Capacity (m) (m) diffusers 1a 4 persons 2.00 1.20 2 1b 6 persons 2.00 1.50 2 1c 10 persons  2.00 1.95 4

[0071] In the embodiment illustrated in FIGS. 4a and 4b, designed for a capacity of 4 and 6 persons respectively, the only thing that varies is the diameter of the reactor 10, the spacing of the diffusers acting in each virtual semicircle (15, 16) of the reactor and the size of the blower feeding those diffusers.

[0072] In the case of FIG. 4c, the diffusers 11 are distributed in pairs within each virtual semicircle (15, 16), so that each pair of diffusers 11 is fed by the same solenoid valve, unlike the embodiments of FIGS. 4a and 4b, where each diffuser 11 is fed by a separate solenoid valve.

[0073] The proposed system, in order to operate in safe terms having a reduced volume, is equipped with an overflow detection means that allows the evacuation of excess water from inside the reactor 10 without losing biology. To perform said evacuation and according to FIG. 1, the system comprises an overflow tube 50 located at a desired maximum level of fluid in the tank and which prevents a sudden increase in flow rate from exceeding said maximum level. Said overflow tube 50 projects into the reactor 50 up to the minimum operating level and with a slope preferably of 60° to prevent loss of the biology present in the reactor. Furthermore, at its end to the interior of the reactor it has an opening 51 in chamfer type cut to prevent the entry of bubbles. Preferably, the overflow tube 50 has a diameter of 75 mm.

[0074] To perform this emergency operation, either the pumping chamber 20 or the reactor 10 comprises an overflow sensor (not illustrated) which when activated, the programmable logic control acts by suspending the cycle in progress. A set sedimentation time is then initiated. Subsequently and through the overflow pipe 50 whose opening 51 is at a higher suction point than the open end 13.5 of the clarified water conduit 13, the excess water is evacuated from inside the reactor to a disinfection plant, an operation that has very little chance of entraining biology, since the suction point is already in a zone of clarified liquid and its inclination produces the effect of lamellar settling, that is, it allows the biology to decant inside the reactor faster than it would tend to flow out of the tube towards the outside of the reactor.

[0075] This emergency operation could be extended for as long as necessary until the level sensor is deactivated. When the latter has happened, the scrubbing cycle is resumed if it is on schedule.

NUMERICAL REFERENCES

[0076] 10 Reactor [0077] 11 Diffuser [0078] 12 Sludge outlet duct [0079] 12.1 First curved portion [0080] 12.2 First vertical portion [0081] 12.3 Second curved portion [0082] 12.4 Second vertical portion [0083] 12.5 Open end [0084] 13 Clarified water outlet duct [0085] 13.1 First curved portion [0086] 13.2 First vertical portion [0087] 13.3 Second curved portion [0088] 13.4 Second vertical portion [0089] 13.5 Open end [0090] 14 Support [0091] 15 First virtual semicircle [0092] 16 Second virtual semicircle [0093] 20 Pumping chamber [0094] 21 Inlet pipe [0095] 22 Submerged pump [0096] 23 Feed pipe [0097] 24 Wastewater inlet [0098] 30 Valve arrangement [0099] 31.1 First valve [0100] 31.2 Second valve [0101] 31.3 Third valve [0102] 31.4 Fourth valve [0103] 32.1 First hose [0104] 32.2 Second hose [0105] 32.3 Third hose [0106] 32.4 Fourth hose [0107] 33.1 First starter collar [0108] 33.2 Second starter collar [0109] 40 Blower [0110] 50 Overflow tube