This Non-provisional application claims priority under 35 U.S.C. ยง 119(a) on Patent Application No(s). 2003-199167 filed in Japan on Jul. 18, 2003, the entire contents of which are hereby incorporated by reference.
1. Field of the Invention
The present invention relates to a reservoir tank for storing a liquid, and in particular to a reservoir tank whose bottom structure is improved.
2. Description of the Related Art
There is a reservoir tank for storing a liquid. It is necessary to seal the inside of the reservoir tank in order to prevent the stored liquid from leaking. If the bottom of the reservoir tank corrodes due to deterioration and so forth, the liquid is likely to leak therefrom. For the purpose of preventing the stored liquid from leaking out of the reservoir tank, various ideas are conceived regarding a bottom structure of the reservoir tank, such as described in Japanese Patent Laid-Open Publication No. 9-272991, for example. The Publication No. 9-272991 relates to an electric anticorrosion method for an outer surface of a tank bottom plate to be placed on an asphalt sand. With respect to this method, linear insoluble electrodes are arranged on the asphalt sand in a lattice state. A conductive material is laid over the whole surface of the asphalt sand so as to cover the insoluble electrodes. Further, a sand layer is formed on the conductive material. The insoluble electrode is connected to a plus side of a DC power supply and the tank is connected to a minas side thereof to supply a predetermined anticorrosive current to the outer surface of the tank bottom plate.
However, as for the electric anticorrosion method of the above-noted publication wherein an external power-supply system is adopted for the outer surface of the bottom plate of the outdoor tank, it is necessary to lay the linear insoluble electrodes on the asphalt sand, on which the reservoir tank is placed, in the lattice state. Thus, there arise problems in that an installation operation takes a lot of labor and the cost increases. In a case of the outdoor-type reservoir tank having a large size, it is impossible to transfer it through a general rode. Therefore, welding for assembly is performed at a place for setting the reservoir tank. Sometimes it is impossible to deal with the reservoir tank such as described in the above-noted Publication No. 9-272991. Further, it is difficult to externally check the liquid leaking out of the bottom. In case the liquid leaks out of the bottom, there arises a problem in that the leakage liquid pollutes the underground.
In view of the foregoing, it is a primary object of the present invention to provide a reservoir tank adapted to prevent underground pollution to be caused by a liquid, which has leaked out of the bottom thereof.
It is a second object of the present invention to provide a reservoir tank adapted to securely retrieve a leakage liquid.
In order to achieve the above and other objects, the reservoir tank according to the present invention comprises a tank body and a double bottom. The tank body stores a liquid. The double bottom is fixed to the bottom of the tank body. It is preferable that the double bottom has an airtight structure and a declivity. Further, it is preferable that the double bottom is provided with a port for detecting gas concentration.
In a preferred embodiment, the double bottom comprises a reinforcement member for supporting a tank bottom plate of the tank body. The reinforcement member is formed with a cutout through which the leakage liquid is allowed to move. Moreover, it is preferable that the double bottom has an outlet for discharging the leakage liquid accumulated in the double bottom. The tank is preferable to be a large-sized outdoor tank of which the tank body is directly fixed to a base.
According to the reservoir tank of the present invention, the liquid having leaked from the tank body is accumulated in the double bottom so that the liquid is prevented from flowing out of the reservoir tank. Since the double bottom has the airtight structure, the leakage liquid is surely prevented from flowing out of the reservoir tank all the more.
The double bottom has the declivity so that the leakage liquid is easily discharged to the outside. Since the double bottom is provided with the port for detecting gas concentration, it is possible to confirm whether or not the liquid leaks from the tank body to the double bottom. Moreover, since the double bottom has the outlet for discharging the leakage liquid of the double bottom, the leakage liquid, which is accumulated in the double bottom, is easily discharged to the outside.
The above objects and advantages of the present invention will become apparent from the following detailed description of the preferred embodiments of the invention when read in conjunction with the accompanying drawings, in which:
As shown in
As shown in
The roof 8 has a taper shape going down toward the edge thereof. The wall segment 11a of the tank body 3 is formed with a maintenance opening 16 to which a flange 17 is fitted so as to cover it. When the inside of the tank body 3 is checked and cleaned, the flange 17 is detached. Incidentally, the roof 8 may be vertically moved, instead of attaching to the tank wall 10, depending on an amount of the liquid 6 stored in the tank body 3.
An inlet pipe 18 is attached to the roof 8. The inlet pipe 18 is inserted into the tank body 3. The liquid 6 is injected into the tank body 3 through the inlet pipe 18. An outlet pipe 19 is attached to the wall segment 11d. The outlet pipe 19 is welded to a through hole 20 (see
As shown in
The rim 22 is formed with three detection ports 27 for detecting the liquid 6 leaking from the tank body 3. The detection ports 27 are positioned at intervals of 120 degrees, for example. A checking pipe 28 (see
As shown in
The double bottom 4 is fixed to a concrete base 30 made in the outdoors. The concrete base 30 has a cutout through which the discharge pipe 31 passes to connect with a recovery pit 33. An exit of the discharge pipe 31 is provided with a valve 32. By opening this valve 32, the liquid 6 accumulated in the double bottom 4 flows into the recovery pit 33 to retrieve the liquid 6. By the way, instead of the discharge pipe 31, a recovery port may be formed in the rim 22. The recovery port is usually closed with a flange or the like, and is opened by detaching the flange to retrieve the liquid 6.
After assembling the double bottom 4 on the concrete base 30, the tank body 3 is built on the double bottom 4 such as described above. The first wall 11 of the tank body 3 is fixed to the rim 22 of the double bottom 4 by means of welding. Thereupon, the inside of the double bottom 4 becomes an airtight state.
As just described, the double bottom 4 is fixed to the bottom portion of the tank body 3 and the inside of the double bottom 4 is sealed. Thus, in case the liquid 6 leaks from the tank body 3, the leakage liquid is accumulated in the double bottom 4 and is prevented from leaking to the outside of the reservoir tank 2. Further, by inserting the gas concentration meter and so forth into the detection port 27 formed in the double bottom 4, it is possible to confirm whether or not the liquid 6 leaks from the tank body 3 to the double bottom 4. Since the leakage liquid outlet 24 is formed in the left side of the double bottom plate 21 and is connected to the discharge pipe 31, the liquid 6 accumulated in the double bottom 4 is gathered into the recovery pit 33 through the discharge pipe 31.
Although the present invention has been fully described by way of the preferred embodiments thereof with reference to the accompanying drawings, various changes and modifications will be apparent to those having skill in this field. Therefore, unless otherwise these changes and modifications depart from the scope of the present invention, they should be construed as included therein.
Number | Date | Country | Kind |
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2003-199167 | Jul 2003 | JP | national |
Number | Name | Date | Kind |
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2460054 | Wiggins | Jan 1949 | A |
3902356 | Rupf-Bolz | Sep 1975 | A |
4871081 | Ershig | Oct 1989 | A |
5096087 | Thomas | Mar 1992 | A |
5102803 | Weaver | Apr 1992 | A |
Number | Date | Country |
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10234190 | Feb 2004 | DE |
9-272991 | Oct 1997 | JP |
Number | Date | Country | |
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20050011899 A1 | Jan 2005 | US |