JPS6026893B2 - Drainage and rainwater collection structures - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a drainage and rainwater collection structure, and its purpose is to collect drainage (particularly non-oil-containing drainage) and rainwater within a factory premises and utilize the collected drainage as industrial water.

Japan has long been said to be a country rich in ancient pottery and water, but with the rapid development of industry and population growth, the amount of water used has increased, making it difficult to meet the demand with natural water alone.

For this reason, in industry, cooling water is recycled,
Treated water obtained by purifying sewage and other wastewater through biochemical treatment such as activated sludge method is reused. The amount of water used is expected to increase year by year, so securing the amount of water used is an important issue. In order to solve this problem, the present inventors examined the relationship between water and wastewater, and researched ways to circulate and use a limited amount of raw water and methods for utilizing rainwater.

There are many different types of industrial wastewater, but taking wastewater from oil refining as an example, it is classified into non-oil-containing wastewater, oil-containing cooling wastewater, process wastewater, and sanitary wastewater, each of which is collected and purified if necessary. After that, they are released.

The main object of the present invention is to collect wastewater that does not contain oil, that is, non-oil-containing wastewater and rainwater, and reuse it as water for use.

In factory wastewater measures, rainwater accounts for about 40~40% of the total wastewater volume.
It accounts for 60%, and the drainage equipment is approximately 2-2% during normal operation.
．． It is customary to install one with five times the capacity. However, according to the present invention, part of the rainwater is collected and used, so the original drainage equipment can be made into a 4-type system. The present invention will be explained with reference to the drawings.

FIG. 1 is an explanatory diagram showing one embodiment of the present invention, in which a part of the factory site is excavated and a water collection pond 2 is constructed above with impermeable material.
will be established.

Impermeable materials include concrete, asphalt, metal plates,
Any material such as a synthetic resin plate or synthetic resin sheet may be used, but a material with high flexibility such as silt cement is preferable because it has excellent workability. The size and shape of the catchment pond should be selected appropriately, taking into consideration the surrounding conditions. A water intake tank 3 is arranged in a part of the water collection pond 2. Details of the water intake tank 3 will be described later. Other spaces within the water collection pond 2 are filled with earth and sand with a low effective water content. Such soil includes gravel, pongee sand, coarse sand,
There is also Tsumugi sand soil. The reason why the soil layer 4 is formed in the water collection pond is to effectively utilize the underground self-cleaning action of soil microorganisms and the like. In addition, before filling this earth and sand, it is preferable to fill the periphery of the water intake tank from the inside to the outside with a bottle of crushed stone, gravel, gravel, or lees to facilitate water collection. The upper part of the earth and sand layer 4, that is, the ground surface, is a permeable layer 5 made of a permeable material. The thickness, strength, porosity, etc. of the layer are selected depending on the purpose. Porous asphalt concrete is preferred as the water permeable material used here. Porous asphalt concrete consists of small particle size aggregate and 3-6% asphalt based on the weight of the aggregate, and generally has a porosity of 20-45%. Although crushed stone is preferable as the aggregate, gravel, metal particles, coke, etc. can be used alone or in combination with silk. The particle size of the aggregate is preferably about 1.5 to 1 m.
Asphalt functions as a binding material, and various types such as straight asphalt, blown asphalt, and cat blown asphalt can be used. As a striping aid, for example, natural or synthetic rubbers (rubber latex is particularly preferred), epoxy resin, etc. can be mixed. If the porosity of porous asphalt concrete is less than 20%, water permeability is insufficient, and
If it exceeds 5%, the strength will be insufficient, which is not preferable.
An example of the composition of porous asphalt concrete is 10 parts by weight of crushed stone with a particle size of 2.5 to 5, 6 parts by weight of filler (calcium carbonate), and 4.5 parts by weight of asphalt, with a porosity of 35%. There is something. On the other hand, any means for guiding the non-oil-containing wastewater to the water collection pond may be used, such as providing a drainage ditch or arranging a conduit above or underground.

In this case, it is preferable to be able to adjust the amount of inflow of wastewater. The above-ground map of the water collection basin will be made slightly higher than the ground level by placing blocks 6, etc.

FIG. 2 is an explanatory diagram showing details of the water intake tank 3.

The water intake tank will be placed about 20 to 3 feet above the bottom of the water collection basin, and the space will be filled with crushed stone or gravel. The bottom and side walls of the water intake tank are made of water permeable material 7. As the water-permeable material, the above-mentioned porous asphalt concrete is preferred.
The size, shape, etc. of the water intake tank will also be determined as appropriate, taking into consideration the purpose of use and other factors. It is not preferable to use a reinforced concrete perforated pipe as a water intake tank because the inflow speed of water from the hole is long and the inflow of earth, sand, sediment, etc. is unavoidable.
When porous asphalt concrete is used, water permeates from the entire surface of the tank, and the inflow rate can be adjusted as desired, and it is easy to achieve a rate of 3 k/sec or less, which was previously considered impossible.

Even if the inflow speed is slow, the amount of inflow will not decrease because it can flow from the entire surface of the mill. When installing a water intake pipe, the intake slope should be 1/500 or less, and the average flow velocity at the outlet end should be 0.
．． It is desirable to set it to 3/sec or less.

It is desirable that the side wall surface of the water intake tank is made of an impermeable material such as a reinforced concrete layer 8 above the lowest groundwater level to prevent infiltration of wastewater that has not been sufficiently purified.

Also, for the same reason, the side walls of the water intake tank are more than 30 degrees higher than the ground surface. Water is pumped up from the water intake tank by a water pump 9 and sent to a water storage tank or the like.

The water pump is preferably of an automatic level switch type, and the water intake point 10 at the tip is wrapped in a mesh-like water-permeable material (wire mesh, synthetic resin silk, cloth, etc.), and a chlorine sterilization chamber 11 is provided if necessary. .

In addition, an emblem 12 can be attached to the top of the water intake tank exposed on the ground surface to improve the water pumping capacity. Although the structure of the present invention can be applied to factories in various industries, it is particularly effective when applied to oil refineries, petrochemical factories, etc. That is, since the premises of refineries and the like are regulated to have 10% or more of them as green belts, a large amount of money is required for the accompanying water sprinkling equipment construction. If the structure of the present invention is adopted, this water sprinkling equipment becomes unnecessary or can be reduced in size. Similarly, rainwater drainage construction costs can also be reduced. Since the water quality required for industrial water is almost the same as for drinking water, sufficient consideration is required when collecting and using non-oil-containing wastewater or rainwater.

In the present invention, since the lower layer of the permeable ground surface is a soil layer, drainage water and rainwater are naturally purified as they move downward. Furthermore, when this water enters the water intake tank, it is also purified by earth and sand. Therefore, the water pumped from the water intake tank can be fully used as industrial water.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing the drainage and rainwater collection structure of the present invention, and FIG. 2 is a detailed explanatory diagram of the water intake tank. In the figure, 2 is a blind pond, 3 is a water intake tank, 4 is a sand layer, 5 is a permeable layer, and 13 is a water intake pipe. Figure 1 Figure 2

Claims (1)

[Claims] 1. A water collection basin with a bottom and side walls made of impermeable material is installed on the excavated factory site, and a water intake tank with a bottom and side walls made of permeable material is placed in a part of the water collection basin. , the other part is filled with earth and sand with a low effective water content to make the ground surface a water-permeable layer made of a water-permeable material, and the water intake tank is connected to a means for guiding the water in the tank to the ground. Drainage and rainwater collection structures.