JPS5832790Y2 - abrasive - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an oil recovery device that combines an oil-water separation tank that utilizes the difference in specific gravity between oil droplets and water, and an oil recovery machine.

As a gravity-type oil-water separator that utilizes the difference in specific gravity between oil and water, the American Petroleum Institute (API)
The API oil wood separation device developed at Petroleum Institute (Petroleum Institute) is the simplest and most common method and is used in many ways.

In the API device, the length, depth, and width of the channel are calculated based on the experimentally determined floating speed so that oil droplets with a diameter of 150 μm or more can be floated and separated inside the device.

At the downstream end of the flotation and separation channel, a partition having a water passage at the bottom is arranged, and a rotary oil collecting pipe is provided in front of the partition.

Therefore, with the API device, oil droplets with a diameter of 150μ or more can be collected by a rotating oil collecting pipe.

However, since the floating speed of an oil droplet is proportional to the square of its diameter,
If it is attempted to collect even finer oil droplets using an API device, the total length of the oil-water separation tank will become extremely long, which is undesirable as it will increase the equipment cost.

In order to avoid the above-mentioned problems, this invention places a coarse-grained net in front of the oil recovery machine to give the fine oil droplets a chance to meet and grow into larger oil droplets, improving recovery efficiency. It is.

Next, it will be explained with reference to the drawings.

In Fig. 1, 1 is an oil-water separation tank, and 2 is a belt-type oil recovery machine. It is possible to remove the sludge that has accumulated in the tank.

An inlet 6 is opened in the side wall of the main body above the sludge storage 3, and a dust removal basket 7 is attached to the inlet 6.

The dust removal basket 7 is made of a wire mesh for removing coarse garbage from the oil-containing wastewater introduced from the inlet 6, and the coarseness of the wire mesh varies depending on the type of wastewater, but is preferably about 1 to 5 mesh.

The flow rate of the wastewater that has passed through the inlet 6 and the dust removal basket 7 decreases in the tank 1, so that foreign matter (sludge) sinks into the sludge storage 3.

Inside the tank body 1', oil droplets of length L and width B (Fig. 2) are floated in the downstream (right side of the figure) of the sludge storage 3, allowing oil-containing wastewater to flow quietly at depth D. A separation channel 8 is provided, and the values of depth D, length L, and width B are such that while the wastewater passes through the interior, oil droplets with a predetermined particle size or more completely reach the surface. It can be determined experimentally or by a calculation formula developed by the API, taking into consideration the amount and properties of wastewater and including a safety factor.

The channel 8 is provided with a partition 9 at its downstream end, and the water flowing at the bottom of the channel 8 passes through a water channel 10 below the partition 9 into a channel 8' downstream of the partition 9.

11 and 12 are coarse-grained nets arranged so as to fill the cross section of the channel 8, and these are elements 1 made of foam material or cloth having interconnected air cells inside the corrosion-resistant cage.
1' and 12' are filled and inserted from above into the grooves 13 and 14 provided in the inner wall of the tank body 1'.

The elements 11' and 12' are preferably hydrophobic and lipophilic, such as commercially available polyurethane foam or polypropylene cloth.

Coarse particles) 11.12 promote the association of oil droplets in wastewater, provide a place for fine oil droplets to grow into larger oil droplets, and serve as a filter for suspended contaminants.

An endless belt 15 made of lipophilic material of the oil recovery machine 2 is immersed in the water surface between the net 12 and the partition 9, and the oil floating on the water surface is pulled up into the recovery machine 2 by being driven to circulate in the direction of the arrow. The oil is then squeezed out by a squeezing roller (not shown).

Reference numeral 16 indicates a frame, and reference numeral 17 indicates a drainage pipe for returning water separated within the recovery machine 2 into the flow path 8.

On the downstream side of the partition 9, in front of the discharge port 19, a capture net 20 is provided to capture remaining oil droplets that did not float (usually have an oil droplet diameter of 120 to 150 μm or less).

This net 20 is a corrosion-resistant basket filled with polypropylene foam, similar to 11.12.
It is inserted from above into a groove 21 provided on the inner wall surface of the tank body 1'.

Therefore, like the nets 11 and 12, the net 20 can be replaced with a new or recycled product as appropriate depending on the oil absorption capacity.

In order to increase the efficiency of the drain port 19 (20), a suction pipe 22 extending downward is provided so that only moisture can be discharged from the bottom of the channel 8', and the moisture can be discharged in a siphon style.

While the wastewater from which coarse dirt and sludge have been removed by the dust removal basket 7 and the sludge storage 3 moves slowly downstream in the channel 8, most of the oil droplets inside float to the surface due to the difference in specific gravity.

When the wastewater roughly separated into oil and water passes through the coarse-grained net 11.12, fine oil droplets are given an opportunity to grow together within the net 11' and 12'. The part of the wastewater that has passed through is further separated into water and oil, and then the belt 1 of the oil skimmer 2
5 effectively recovers the oil at the top.

Further, the fine oil droplets still contained in the wastewater that has exceeded the partition 9 are adsorbed by the capture net 20, and the oil content on the downstream side of the net 20 is greatly reduced.

Moreover, since the discharge port 19 is opened at the bottom of the tank by the suction pipe 22, the discharge of oil droplets is also prevented here.

The effects of the present invention are listed below: (1) The structure is simple, easy to handle, and of high practical value.

(2) The oil/water separation tank 1 is not only made of concrete but also made of iron plate.
It is economical because it can be easily manufactured as a unit using FRP or the like.

(3) In combination with the oil recovery machine 2, it is possible to achieve at least the current regulation value (3 to 5 ppm or less of N-hexane extractables) for oil-containing wastewater in a mechanically suspended state.

(4) Most of the oil in wastewater is recovered as is by the oil recovery machine 2, making it easier to process the recovered material compared to coagulation methods or other electrical or chemical methods. The cost will also be lower.

(5) Since the oil is coarser than the API device) 11.12 is provided, the oil recovery efficiency is improved, the length of the flow path 8 can be shortened, and the processing capacity is also significantly improved.

It is even more effective since it is equipped with a trapping net 20.

3 to 5 show modified examples of the present invention, and the same reference numerals as those in FIG. 1 indicate corresponding parts.

In these modified examples, the flow path 8 for flotation and separation of oil droplets is improved by means of a guide plate 25 so that it meanders within a plane.

Therefore, there is no risk that the oil-containing wastewater in the flow path 8 will cause disturbances such as switching up and down during meandering, and since the flow path length increases, it becomes easier to float smaller diameter oil droplets, which is effective for improving oil recovery efficiency. It is.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of an oil recovery device according to the present invention, FIG. 2 is a plan view, and FIGS. 3 to 5 are plan views showing modified examples. 20... Capture net, 19... Outlet.

Claims (1)

[Scope of utility model registration request] A dust removal basket 7 is attached to the upper part of one end of the oil/water separation tank 1, and an inlet 6 for oil-containing wastewater is opened into the basket 7. Below the dust removal basket 7, there is a sludge storage 3 deeper than other parts, and a drain port with a valve. 4, a long channel 8 necessary for flotation and separation of oil droplets is formed on the downstream side of the sludge storage 3, and a partition 9 having a water channel 10 at the bottom is provided in the cross section of the downstream end of the channel 8. Thick-wall coarse-grained nets 1 made of hydrophobic and lipophilic material are provided on a plurality of cross sections in front of the partition 9, the meshes of which are finer on the downstream side.
1.12 is removably arranged, and the coarse-grained net 1 at the downstream end
The lipophilic endless belt 15 of the oil recovery machine 2 is immersed in the water between the oil recovery machine 2 and the partition 9 and driven to circulate. A suction pipe 22 opened at the bottom of the flow path 8' is placed at the downstream end of the flow path 8'.
An oil recovery device characterized in that it is provided with a discharge port 19 having a discharge port 19.