JPS5852706B2 - Sunano Bunrikaishyuhouhouhou Oyobi Souchi - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method and apparatus for separating and removing foreign matter contained in sewage sediment containing putrefying organic matter or coarse dust to recover clean sand.

The sediment that settles and accumulates on the bottom of the settling basin installed at an urban sewage pumping station is mixed with urban waste along with the sediment until the sewage flows into the settling basin. ), organic matter, coarse dust, etc. are mixed.

This mixed organic matter and coarse dust easily decomposes, emitting bad odors, and attracting pests.

Therefore, since disposal such as dumping or landfilling causes pollution, it has been desired to separate the mixed organic matter and coarse dust to make clean sand and reuse it if possible.

Conventionally, the method of raking sand and separating the organic matter contained therein was to wash the sand with water, air, or water + air in a conveyor trough during transportation or in a sand washing tank after raking, but trace amounts of organic matter were mixed in. However, if a large amount of organic matter is present, it becomes difficult to diffuse and separate the sand, and the sand washing effect cannot be obtained at all.

Another method of removing organic matter was to use a wire mesh or a screen, but these methods clogged severely and were not practical.

Furthermore, as the living standards of citizens have improved, the amount of organic matter in sewage has been increasing at an accelerating rate, and the removal of organic matter has become urgently desired.

In view of the above-mentioned circumstances, it is an object of the present invention to provide a method and apparatus for efficiently separating and recovering highly inorganic sand with good drainage properties, regardless of the amount of putrefactive organic matter and coarse dust mixed in settling sand. shall be.

This invention focuses on the above-mentioned drawback that it is difficult to diffuse and separate the sand even if sewage sediment containing a large amount of organic matter is washed. It was discovered that fibrous organic matter is intertwined with each other, hindering the separation and diffusion of sand and organic matter.

As a result of the test, it is possible to apply impact or vibration to the sand to which the fine fibrous organic matter is attached, and to peel off the attached fine fibrous organic matter due to mutual friction, thereby making it possible to separate and diffuse it.

The main point of this invention is to add an appropriate amount of cleaning liquid to the collected sand containing organic matter and coarse dust, and perform forced friction stirring to form a mixed water that separates and diffuses the sand and organic matter.The coarse dust is removed from this warm water using a screen. Next, the highly inorganic sand content and putrefactive organic matter in the mixed water are concentrated from a mixed state to a separated state due to the difference in specific gravity, and the sand is recovered.

One embodiment of this invention will be described.

The sand 1 scraped up from the sand settling tank and the washing water 2 pumped from the sand settling tank are put into the stirring tank 3, and stirred by the stirrer 4 to peel off the organic substances adhering to the sand and separate and diffuse them. Some of the organic matter with low specific gravity floats between the barrier plate 5 that partitions the corner of the tank 3 and the wall of the tank 3, and is returned to the settling basin from the overflow weir 6 of the tank 3 via the water collection gutter 7 outside the tank. urge

The mixed water of sand, organic matter, and coarse dirt is passed through the slit 8 into an induction tank 9 with no stirring flow, and the coarse dust is removed by a known automatic screen 10 that crosses the flow path of the tank 9, and the mixed water of sand and organic matter is pumped. 11 to a cyclone 12 at high speed.

Washing water containing organic matter separated at high speed by the cyclone 12 is discharged from an upper port 13 of the cyclone 12 and returned to the sand settling basin, and sand separated at high speed is discharged from a lower cyclone port 14 and collected by a conveyor 15.

According to the above treatment, the washing water 2 imparts fluidity to the raked sand, and separates and diffuses the exfoliated organic matter and sand into the washing water.

The agitator 4 collides and rubs the sand to which organic matter is attached, thereby peeling off the organic matter from the sand.

The barrier plate 5 blocks the agitation flow and creates a still water area in which organic matter is suspended.

The slit 8 prevents the stirring flow and stabilizes the flow in the induction tank 9.

The automatic screen 10 automatically scrapes and removes coarse dirt that is caught on the screen, allowing continuous operation of the pump 11.

The pump 11 pumps the mixed liquid into the cyclone 12 at an optimal flow rate.

Cyclone 12 quickly separates organic matter and highly mineralized sand.

The conveyor 15 carries out the separated sand.

The organic matter-containing wash water separated as described above may be returned to the settling basin or may be subjected to other treatment.

As described above, this invention was able to quickly separate and recover highly inorganic sand by separating, diffusing, and centrifuging the organic matter adhering to the sand.

A comparison of raked and settled sand and recovered and separated sand is shown in the table.

[Brief explanation of the drawing]

The figure is an explanatory diagram showing an embodiment of the invention. 3: stirring tank, 9: induction tank, 11: pump, 12: cyclone separator,

Claims (1)

[Claims] 1. A stirring tank containing a sand agitator and an induction tank containing a non-removal screen for coarse dust are installed adjacent to each other, and the two tanks are communicated through a slit, and a cyclone is installed downstream of the induction tank via a pump. A sand separation and recovery device characterized by being equipped with a mold separator.