JPS6333440B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates generally to wastewater purification technology, and more particularly to sewage treatment equipment.

Devices embodying features of the invention are applicable to the treatment of wastewater in ships or buildings and structures not connected to sewer mains.

At present, the problem of pollution in living spaces is arousing worldwide attention. Dumping of waste into rivers, lakes and oceans occupies a special place in the overall pollution of living areas. The rapid development of ships has significantly increased the amount of ship waste dumped into rivers, lakes, and oceans, and as a result, countries around the world have taken measures to exclude ships that are not equipped with wastewater purification and decontamination equipment from their territorial waters. This led to a situation where According to the Agreement on the Prevention of Marine Pollution from Waste and Other Sources, ships must be equipped with such purification and decontamination equipment. Modern marine engineering provides automatic steering of onboard wastewater treatment equipment. Accordingly, there is great interest in developing high performance and trouble-free equipment for the purification and decontamination of shipboard wastewater. Many wastewater treatment devices are currently known that can be applied to ships under construction. but,
Under the terms of the aforementioned agreement, both new and existing ships must be equipped with such wastewater treatment equipment, so this requirement usually applies to older ships with only limited capacity sewage tanks for improved designs. This raises the issue of equipping wastewater treatment methods. Such systems require extensive floor space and generally must be installed separately from the ship's sewage tanks.

The Saren-Battennod wastewater treatment system known as the "Nepteimate Retro" (see Salen-Battennod, Brochure No. 1, published July 16, 1979) is widely used; It includes level meters for the upper and lower water levels in the water tank, and when it receives signals from these level meters,
The switch of the device is opened and closed accordingly. The sewage tank also has a water intake unit whose end facing the inlet of the wastewater is covered with a screen perpendicular to the wall of the housing of the water intake unit and the flow of the wastewater. An intake pipe and a pipe for recirculating untreated water are installed on the inside wall of the water intake unit. The water intake pipe is connected to the suction end of the circulation pump. The pressure end of the circulation pump communicates via a pressure line, a pressure tank and a pressure supply line with a flotation unit in which the waste water is purified. The pressure tank also communicates with pipes that recirculate untreated wastewater. A drain is installed in the piping connecting the wastewater recirculation pipe to the pressure tank, and this drain is intended to vent the water passing through the intake pipe. The discharger is in communication with the gas phase part of the sludge collector and with the clarification water tank. The metering pressure line is typically a length of graduated tube that supplies wastewater at a predetermined rate to the flotation unit.

Reagents such as FeCl ₃ or Al ₂ (CO ₄ ) ₃ are injected with a special pump to coagulate contaminants in the wastewater passing through the pressure tube.

The flotation unit includes a vessel for purifying the water, a scraper for removing flotsam formed during wastewater treatment, and a device for discharging the purified water.

The flotation unit communicates with a sludge collector with a sludge discharge pump and a clarification tank with a clarified water drainage pump. The device further comprises a control section electrically coupled to a circulation pump, a sludge discharge pump and a purified water discharge pump, and upper and lower water level gauges in the sewage tank.

During operation of the device, the circulation pump sucks wastewater from the housing of the water intake unit through the intake pipe and conveys the wastewater under pressure to the pressure tank. Large solids carried by the wastewater are then retained by a network of water intake units. A heavy pressure of about 2 or 3 ata (absolute pressure) is created in the pressure tank. Approximately 60% of the water in the pressure tank is returned to the housing of the wastewater intake unit through the raw wastewater recirculation pipe. An ejector connected to the raw wastewater recirculation line aerates the wastewater, and the wastewater sent to the pressure tank contains a significant amount of undissolved air. Approximately 40% of the wastewater is delivered to the flotation unit via a metered delivery pressure line. This line is designed as a graduated tube, so that under constant water pressure in the pressure tank, the rate of inflow in the metering pressure line is constant or unchanged. A coagulant is injected into the water stream delivered to a flotation unit where gravity flotation occurs. The sludge of sludge formed in this process is transferred by a scraper to a sludge collector, while the purified water is sucked into a treatment water tank. Provisions are also made to inject decontamination solvents into the water stream.

This is due to the fact that large contaminants are retained by the screen, and firstly due to the fact that these large solids are carried away by the return flow of wastewater entering the intake unit through the untreated wastewater recirculation pipe. Therefore, the above-mentioned devices suffer from the drawback of low performance. On the other hand, the net becomes clogged with solid matter generated as the work continues.
As a result of the blockage, the amount of waste water delivered to the pressure tank is reduced, while the amount of waste water discharged from the pressure tank to the flotation unit by the metered delivery pressure line remains constant.
This reduces the amount of water that enters the housing of the wastewater intake unit through the recirculation pipe and flushes or cleans the screen, further increasing the likelihood of blockage of the screen. Therefore, the amount of wastewater supplied to the pressure tank by the circulation pump is further reduced, while the proportion of wastewater discharged from the pressure tank by the metering pressure line remains at the previous level, which reduces the return path of the circulation line. The water flow rate through which the water flows back to the sewage tank is again reduced, and so on. The chain of events described above is irreversible and may even lead to failure of the circulation pump. To prevent this,
Operation must be stopped and the net washed with an external stream of water.

It is an object of the present invention to improve the performance of wastewater treatment equipment by more effective cleaning of the screens of wastewater intake units.

This purpose consists of a wastewater intake unit having a housing provided in the sewage tank and a net covering the tip of the housing facing the wastewater flow, each arranged sequentially along the wastewater flow; a water intake pipe and a recirculation pipe for returning untreated wastewater to the water unit; a circulation pump whose inlet is connected to the intake pipe by a water pipe and whose outlet is connected to the untreated wastewater recirculation pipe; and a metered delivery pressure pipe. a flotation unit connected by a channel to the outlet of the circulation pump; a sludge collector and a treatment water tank, both having a sludge discharge pump and a pump for discharging purified water, respectively, in communication with the flotation unit; A wastewater treatment device including a control section electrically connected to a pump for discharging sludge and discharging purified water, and a level meter for upper and lower water levels in a sewage tank, and further electrically connected to the control section. including a water pressure sensor located in a water pipe connecting the water intake pipe and the inlet of the circulation pump, the outlet of the circulation pump being connected directly to the pipe recirculating untreated wastewater, and electrically connected to the control section. This is achieved by providing the wastewater treatment device characterized in that a connected self-closing valve is arranged between the circulation pump flotation unit of the metering line.

Preferably, the waste water intake unit includes a casing which is fastened to the front of the screen and has openings in its lower part for the passage of waste water, and the screen of the water intake unit is oriented at an angle of 30 to 40 degrees to the waste water flow path. A stream of untreated water, inclined at an angle and supplied by a circulation pump, passes through the screen, reverses from the casing, and acts on the surface of the screen to wash it of contaminants.

When using the present device for wastewater treatment, a more reliable purification of wastewater is guaranteed without the need for personnel to be present.

The wastewater treatment apparatus according to the present invention includes a wastewater intake unit 1 (FIG. 1), an upper water level gauge 2 and a lower water level gauge 3 in an onboard sewage tank 4. The water intake unit 1 has a housing, generally designated 5, with a casing part 6 open at its lower side. The end of the housing 5 facing the wastewater flow is covered with a screen 7. The water intake unit 1 has an intake pipe 8 for receiving incoming wastewater and a recirculation pipe 9 for recycling untreated wastewater. The water intake unit 1 is also provided with a device 10 for washing the screen 7, which device 10 is installed inside the housing 5 and is connected to the outside main water pipe (not explicitly shown) via an automatically actuated inlet valve. contact.

The water intake pipe 8 is connected to the inlet of a circulation pump 14 through a water pipe 12 and a valve 13. The water pipe 12 houses a water pressure sensor 15. The circulation pump 14 is a water pipe 16
and is connected to the untreated wastewater recirculation pipe 9 through a valve 17. The water pipe 16 has an automatic operating valve 19 and a flow rate adjustment membrane 2.
It communicates with the flotation unit 21 via a metering pressure line 18 with 0. The flotation unit 21 is connected via a water pipe 22 to a treated clarified water tank 23 and via a water pipe 24 to a sludge collector 25 equipped with a fan 26. Next, the treated purified water tank 23 is connected to a purified water discharge pump 28 via a water pipe 27,
On the other hand, the sludge collector 25 is connected to the sludge discharge pump 3.
Concatenate with 0. The sludge is collected in the sludge collector 25.
From there, a sewage tank 4 is installed along a water pipe 31 equipped with a valve 32.
It can be discharged to the vessel or via a water pipe 33 provided with a valve 34 onto the ship (not explicitly shown).

The device further includes a control section 35, which includes an upper water level gauge 2, a lower water level gauge 3, a circulation pump 14, a purified water discharge pump 28, a sludge discharge pump 30, automatically operated valves 13, 17, 19, and a fan 26. It is also connected to the water pressure sensor 15 by an electric wire.

In order to have a more pronounced effect on the contaminants clogging the net 7 of the water intake unit 1 and to increase the efficiency of cleaning the incoming wastewater, the net 7 (Fig. 2) is set at an angle of 30 to 40 degrees with respect to the flow of the waste water. The stream 36 of untreated wastewater flowing into the water intake unit 1 after being recirculated by the circulation pump 14 is arranged at an inclination of
The casing 6 provided on the front side of the net 7
It then turns over, thus acting on both the inner and outer surfaces of the screen 7 and flushing the contaminants from the screen to the bottom of the sewage tank.

The angle of inclination of the net 7 is preferably in the range of 30 degrees to 45 degrees. This is because it is at such an angle that the force of the water flow reversed from the casing 6 of the water intake unit 1, as well as the force and gravity of the water flow of the untreated wastewater entering from the pipe 9 recirculating the raw wastewater, are most effective. This is because it is guaranteed only by

If the angle of inclination of the net 7 exceeds 45 degrees, the efficiency of the scraping force generated by the water flow reversed from the casing 6 decreases significantly, while below 30 degrees a sharp decrease in gravity occurs, thereby The water flow reversed from the casing 6 is unable to scrape the contaminants from the surface of the screen 7, and the contaminants tend to stick further.

The wastewater treatment device according to the invention operates as follows.

The circulation pump 14 (FIG. 1) sucks wastewater from the housing 5 of the wastewater intake unit 1 through the net 7 and conveys it from the pipe 8 to the water pipe 16. Large contaminants or solids carried by the water flow cannot pass through the screen 7, while the casing 6 prevents large solids suspended in the wastewater from passing through the screen 7. Housing 5 of waste water intake unit 1 under water pressure below a predetermined value in water pipe 12 following the inlet of circulation pump 14
At normal flow rates of water delivered to the water pressure sensor 15
does not generate a signal to the control section 35 and therefore the valve 19 of the metering pressure line 18 does not open. Water pipe 1
The water flow along 6 is divided into two. The lower flow rate (approximately 30%) enters the metering pressure line 18, and the higher flow rate (approximately 70%) returns to the untreated wastewater recirculation line 9. This water flow separation is carried out by the quantitative delivery pressure line 18.
This is ensured by the membrane 20 placed therein. The wastewater being treated passes through this pressure line 18 to the flotation unit 21 where it is finally purified and decontaminated. The resulting sludge is discharged from flotation unit 21 through water pipe 22 to treated water tank 23. Waste water intake unit 1 from water pipe 16
A stream of water flows into the housing 5 and washes away large solid objects from the screen 7.

When the screen 7 begins to become clogged with contaminants, the water pressure in the water pipe 12 in front of the circulation pump is detected by the water pressure sensor 15.
actuated to transmit a signal to the control section, which signals the valve 19 of the metering pressure line 18 to close. In the closed state of the valve 19, all water flow drawn up by the circulation pump 14 enters the untreated wastewater recirculation pipe 9 through the water pipe 16, from where it returns to the housing 5 of the wastewater intake unit 1. As a result, the flow of water directed by the water tube 16 toward the screen 7 is intense, facilitating efficient flushing of the screen 7 and removing entrenched contaminants from the screen. The arrangement of the casing 6 and the slope of the screen relative to the direction of the recirculating water flow further facilitate cleaning of the screen 7.
After passing through the open eyes of the screen 7, the recirculating water stream 36 (FIG. 2) turns away from the wall of the casing 6 and flows at an acute angle to the outer surface of the screen 7. The contaminants that block the mesh 7 are therefore acted upon from two sides. That is, the return flow 36 of wastewater acts on blockages from inside the housing 5 and forces them away from the screen, while the reversed flow 36 from the casing 6 tends to scrape contaminants from the outside surface of the screen 7. This dual effect of waste water circulation makes the cleaning efficiency of the net 7 very high. Net 7 cleaned in this way
promotes the inflow rate from the sewage tank 4 to the waste water intake unit 1, and the resulting drop in water pressure at the inlet of the circulation pump 14 (FIG. 1) causes the water pressure sensor 15 to increase.
When the signal is again activated and communicated to the control section 35, the control section 35 opens the automatic valve 19 in the metering pressure line 18 and the wastewater stream enters the flotation unit 21.

The sludge produced during the waste water purification process in the flotation unit 21 is conveyed by a water pipe 24 to a sludge collector 25, from where it is sucked by a pump 30 along a water pipe 29 for further use.

The sludge collector is ventilated by a fan 26.

The purified water conveyed from the flotation unit 21 to the treated water tank 23 along the water pipe 22 is discharged onto the ship through the water pipe 27 by a pump 28.

In view of the above, it can be seen that by using the proposed device, when the net 7 becomes clogged with contaminants, it does not impede the reliable operation of the system incorporated in the device and does not require the intervention of the crew. Automatically wash the net 7 without
It is possible to wash it.

The screen 7 can also be automatically cleaned by opening the valve 11 and supplying the cleaning liquid to the screen cleaning device 10, and within 3 minutes after starting the automatic valve 19, the inlet of the circulation pump 14 is If no increase in water pressure occurs, the screen washing device 10 will automatically operate.

Moreover, since such a device can be easily installed in a relatively small space in a machinery room, its use onboard ships allows for the supplementation of existing wastewater treatment equipment at minimal cost. For example, for a ship with 50 crew members
Requires a volume of 1.7cm ³ and an area of only 0.7m ² . Moreover, the present system can be operated using the existing sewage tank without disassembling and inspecting the sewage treatment equipment on board.

[Brief explanation of the drawing]

FIG. 1 is a functional diagram of a wastewater treatment device equipped with a wastewater intake unit according to the invention, shown in longitudinal section. FIG. 2 is an enlarged sectional view of the wastewater intake unit of the wastewater treatment apparatus according to the present invention. 1...Wastewater intake unit, 2...Level meter for upper water level, 3...Level gauge for lower water level, 4...Sewage tank, 5...Housing, 6...Casing, 7...
...Net, 8...Wastewater intake pipe, 9...Untreated wastewater recirculation pipe, 10...Net washing device, 11, 13, 1
7, 19, 32, 34... automatic valve, 12, 16,
22, 24, 27, 29, 31, 33... water pipe,
14...Circulation pump, 15...Water pressure sensor, 18
...Quantitative delivery pressure pipe line, 20...Flow rate adjustment membrane, 2
1...flotation unit, 23...treated water tank, 25
...Sludge Collector, 26...Juan, 28...
Purified water discharge pump, 30...Sludge discharge pump, 35...Control classification.

Claims (1)

[Scope of Claims] 1. Wastewater comprising housings 5 provided in the sewage tank 4 and a net 7 covering the tip of the housing 5 facing the wastewater flow, each sequentially arranged along the wastewater flow. A water intake unit 1, an intake pipe 8 for taking in waste water and a recirculation pipe 9 for returning untreated waste water to the water unit 1, an inlet connected to the intake pipe 8 by a water pipe 12 and an outlet for recycling untreated waste water. A circulation pump 14 connected to the circulation pipe 9 and a flotation unit 21 connected to the outlet of the circulation pump 14 by a metered delivery pressure line 18, both in communication with the flotation unit 21, and a sludge discharge pump 30 and a purification unit, respectively. A sludge collector 25 and a treatment water tank 23 each having a pump 28 for discharging purified water, the circulation pump 14, pumps 28, 30 for discharging sludge and discharging purified water, and level meters for the upper and lower water levels in the sewage tank. 2 and 3 and a control section 35 electrically connected to the control section 35, and a water pipe 12 electrically connected to the control section 35 and connecting the water intake pipe 8 and the inlet of the circulation pump 14. The circulation pump 14 includes a water pressure sensor 15 arranged therein.
The outlet of the circulation pump 1 of the metering line 18 is connected directly to the pipe 9 for recirculating the untreated wastewater, and the self-closing valve 19 is electrically connected to the control section 35.
The wastewater treatment device is arranged between four flotation units 21. 2. The waste water intake unit 1 includes a casing 6 which is fastened to the front side of a screen 7 and has an opening for passage of waste water in its lower part, and the screen 7 of the water intake unit 1 is oriented at 30 degrees to 40 degrees with respect to the flow path of the waste water. The flow of untreated wastewater, which is inclined at an angle of A wastewater treatment device according to claim 1, characterized in that: