The invention relates to an eddy manhole used in replacement of a septic tank to collect domestic wastewater. The eddy manhole consists of a cylindrical main body; a lid; a bottom; an eddy gutter defined by the main body and a lateral wall to form a downward-pointed spiral-shaped groove with a slope i, an end of the eddy gutter being arranged behind the entrance; a waste capture basket located below the exit of the trough, below the still water; an insoluble waste barrier arranged in front of the exit, the lower edge of the insoluble waste barrier equal to the still water level of the eddy manhole.


The proposed manhole design, in particular the eddy wells used in wastewater collection systems.


Typically, in the wastewater collection system in use, black water sources (effluent from urinals and urinals) and gray water effluent (waste water from kitchens, bathrooms, washing machines and water Other wastewater is discharged into the public sewer prior to treatment in the centralized treatment area where the gray waste water leads directly to the public sewer and the black waste water must be discharged through the septic tank before draining into sewer.

Septic tanks have long been used in wastewater collection systems and have the effect of dissolving soluble solids in toilet bowl dispensers such as human excrement, toilet paper, insoluble solids such as sanitary napkins, paper bags, etc., do not allow them to drift into the waste water collection pipe after the septic tank. The septum is an anaerobic tunnel so that it can decompose some organic matter in the water by means of anaerobic microorganisms in it. However, the amount of anaerobic microorganisms in the septic tank is not so great that they cannot decompose all the organic components present in the wastewater. Many experiments show that the BOD content of wastewater is reduced by 30% when passing through the septic tank, 70% of the BOD and other organic components in the wastewater continue to pour into the collection tube, the wastewater after the septic tank is very heavy. The cost of constructing septic tanks is quite high but the effect (as mentioned above) is not large, causing waste in investment. Rapid septic tanks are filled with debris, sand,.., in the wastewater, usually after 5 to 7 years of use, people need to smoke and clean the septic tank, very annoying, expensive and contaminating the environment.

In addition, because only black waste water flows through the septum, the gray waste water from the kitchen, washing machine, bathroom, floor washing,.., has not been processed, not passing through the septic tank but poured into the pipe collect. In gray wastewater there are many objects that are insoluble or insoluble such as leafy vegetables, vegetable stalks, rice husks, hairs, muds, etc. They accumulate on the collecting pipes to clog pipes and stink during decomposition. Therefore, in the collection system in use, the pipe collected in this case has a large diameter (prolonged use due to avoidance of the rule), the actual collector pipe is usually made of concrete pipe, or square trench with cover made of concrete blocks for easy removal and cleaning… The stench situation along the collection system located along the street is very heavy smell, polluting habitat in urban areas and concentrated residential areas. Cleaning work, pipeline collection is very troublesome, costly, affecting the community activities and polluting the environment.

Some types of manhole are known, but the treatment efficiency is not high, waste water after treatment still contains many non-soluble objects, almost remain the same state, size as when not processed.

Due to these disadvantages, it is desirable to produce a system that can collect and treat both black and gray water with higher efficiency.


A manhole are proposed to be used in wastewater collection systems where both wastewater and gray wastewater are fed into the manhole including the cylindrical main body; lid; bottom; the eddy manhole is limited by the main body and a lateral wall to provide a helical guide downward with a slope of i, the eddy manhole head positioned after the inlet; the sloping wall (7) is sloped downwards, facing inward from the main body, located beneath the gates of the eddy manhole to gather objects from the eddy manhole to the center of the eddy manhole; The garbage can (6) is located on the underside of the tilt wall, below the exit of the trough and below the still water; the insoluble waste is arranged in front of the exit. The bottom edge of this waste shaft is at par with the static water level of the manhole. The advantages of this system are:

  1. Thanks to the special structure in the turbine vane with trough and inclined walls, it quickly dissolves completely soluble solids in the wastewater when flowing into it (manure, toilet paper). Waste flows through the manhole to the collecting pipe in the form of slurry. On the other hand, thanks to the network of garbage racks placed at the bottom of the eddy manhole to prevent insoluble solids (women’s toilet paper, glossy paper bags, vegetable leaves, vegetable stems, tubers, fruits, tangled hair, human unintentionally put into the waste water source) not allowing them to flow into the collection pipeline; Sand in the waste water settling down the pit. Water after the whirlpool completely eliminates the risk of clogging collectors, thereby reducing the diameter of the collecting pipe, reducing the slope of the collecting pipe, reducing the back or eliminating the manhole intermediate, saving investment costs and easier in the construction of pipe collectors.
  2. From the above use, use a eddy manhole manhole to eliminate the use of septic tanks, meaning that the eddy manhole shafts used in the new system will play the role of septic tanks. Further clarification: Wastewater treatment has the advantage of the eddy manhole flow in the trough and the force generated by the potential impact on the static water, the insoluble wastes will be disintegrated, the sludge will be kept in the sand pits. Insoluble wastes and sludge in the wastewater will be retained in the trash can and the bottom of the manhole (sand pits) to facilitate cleaning. The wastewater, after flowing through the manhole, is in the form of a slurry, free of insoluble insoluble solids (sanitary napkins, tangled hairs, nylon bags…) and large soluble solids person, toilet paper…). The amount of wastewater that is permanently present in the turbine nozzle does not exceed 42 liters (for whirlpools used for one to three households), with tight lid system, odor of this wastewater does not affect the environment.


Figure 1 is a vertical cross-sectional drawing of a eddy manhole according to the invention;

Figure 2 is a sketch showing the eddy manhole of B-B on Figure 1;

Figure 3 is a partially cut perspective view showing the eddy manhole.


Hereinafter, the invention will be described according to the drawings. Eddy manhole 1 of the invention has a structure comprising a cylindrical main body 2, a cap 3, a bottom 4, a trough 5. The trough 5 is delimited by the main body 2 and the sidewall 51 to form a profile groove downward spiral. Thanks to the helical structure, the length of the waste transport path increases to more than 3.14 times, the slope for the trench is greater or 1% to increase the velocity of the waste, thus the waste is partially discomposed.

According to the embodiment shown in the drawings, the trough comprises only a spiral and a constant swirl width. However, it is possible to make a swirl that consists of several spiral rings in a different way and the width of the groove may vary throughout the length of the groove to increase the force, i.e., the width of the groove to be narrowed.

Entrance 10 is connected to the main body 2 at the entrance of the eddy manhole, ie at the top of the helical conductor. The outlet of the trough 5 is formed at the end of the spiral duct. The outlet of the trough is set higher than the static water level of the eddy manhole and the flow direction down to the center of the eddy manhole. As such, the potential energy of the flow generates a static force acting on the static water that dissolves partially disrupted objects after flowing in the trough. Consequently, objects such as solute or soluble waste will be subjected to continuous forces that further disintegrate.

Under the static water surface there is a trash can 6 to retain the insoluble matter due to the inadvertent user. At the same time, garbage bin 6 (resulting from floor cleaning) flows through and settles beneath the bottom of the manhole, the amount of settling sand is removed by manual methods such as dredging by the hopper. The amount of sand deposited on the bottom of the garbage can. In addition, the trash can 6 is positioned on a tilted inclined wall 7 to indicate that the objects have not been dissolved centrally around the stationary water at the manhole center, above the trash can. The water from the outlet of the runner 5 will dissipate the dissolved objects. According to the results, the optimum tilt is 45 °. Basket-shaped basket racks enhance the storage capacity of insoluble waste and facilitate the removal of waste from the manhole.

Exit 20 is located on the main body 2, an insoluble waste bundle 9 is arranged in front of the exit 20. The lower edge of the waste shaft is transversely to the static water level of the turbine cavity, whereby the substance No solids are flowing into the outlet 20, ensuring no solid objects enter the sewage collection system behind the manhole.

The static water is higher than the top of the trash can. 6, the sand pit 8 contains high water to the static water surface. Water is stored continuously to make waste such as toilet paper, so that dissipation will be easier, at the same time, sand settling to the bottom of the pit.

The top of the eddy manhole manhole has a lid 3, the cap edge and the conical flanges form the cone opposite in order to fit so that the odor from the manhole does not diffuse into the environment.

Turbine vents are made in modular form with various specifications suitable for different collection sizes; Materials made of FRP (Fiberglass Composite) or Stainless Steel 304 are durable in the natural environment.

Advantages of the manhole:

  1. Investment cost savings:

(first). Excluding septic tanks, eddy manhole charges = 1/8 to 1/20 of septic tank cost.

(2). Reduced construction time: Eddy wheel installation time = 1/20 time of septic tank construction.

(3). The wastewater, after flowing through the manhole, is in the form of a slurry, free of insoluble insoluble solids (sanitary napkins, tangled hairs, nylon bags…) and large soluble solids people, toilet paper…) to reduce the slope of sewage collection pipes without fear of congestion, save investment costs, installation and increase the safety of the pipe system. collect.

(4). The waste does not exist on the collecting pipe, so it is possible to shrink and remove some of the intermediate manholes on the waste water pipeline, save on investment costs, operation and maintenance costs of medium manholes, space and shorten construction time.

  1. Operating cost savings:

(first). Excludes annual cost of smoking.

(2). The cost of sanitary eddy manhole cleaning in a simpler way than suction extraction, the process of cleaning the manhole will provide feedback on the sense of community drainage, step by step. change the habit of arbitrarily discharging solid waste into the drainage system of the population.

  1. Prevent environmental pollution:

(1). Vented skirt caps and rubber gaskets, the amount of waste water remaining in the turbine, gas and odor in the wastewater diffuse into the environment.

(2). Removal of septic absorption increases the time between closure evaporation times, thus reducing the pollution at each septic tank vacuum and cleaning the pipeline.


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