US3501917A

US3501917A - Liquid storage

Info

Publication number: US3501917A
Application number: US737028A
Authority: US
Inventors: Clyde V Detter
Original assignee: Phillips Petroleum Co
Current assignee: Phillips Petroleum Co
Priority date: 1968-06-14
Filing date: 1968-06-14
Publication date: 1970-03-24
Anticipated expiration: 1987-03-24

Description

March 1970 c. v. DETTER I 3,501,917

LIQUID STORAGE Filed June 14. 1968 ORIGINAL GRADE LEVEL FIG.

O INVENTOR. c. v. DETTER (.0

BY 5 :5 q Q '52 m A T TORNEYS United States Patent 3,501,917 LIQUID STORAGE Clyde V. Detter, Bartlesville, 0kla., assignor to Phillips Petroleum Company, a corporation of Delaware Filed June 14, 1968, Ser. No. 737,028 Int. 'Cl. B65g 5/00; E211? 17/16 US. Cl. 611 9 'Claims ABSTRACT OF THE DISCLOSURE In many regions there is an acute need for an efficient, low cost reservoir for collecting and storing surface water. In view of the fact that the soil in many arid regions is porous, temperatures are normally high, and winds may be quite strong, conventional open pit storage is not satisfactory. Water is lost from such pits at excessive rates due to seepage into the soil and evaporation. While these storage pits can be lined with an impermeable material to reduce seepage losses, evaporation still is a major problem. Although various types of covers have been proposed in the past, these devices are either quite expensive or are not effective to eliminate evaporation losses.

These problems are solved in accordance with the present invention by the use of a cover which is made of a relatively thin, flexible material. For example, polyethylene film of approximately 10 mil thickness can be employed. While film of this type meets the requirement of low cost, there is a serious danger that the film will be destroyed by wind action. This problem is overcome in accordance with the present invention by controlling the pressure within the reservoir between the surface of the water and the film. In one embodiment, the pressure in this region is reduced so that atmospheric pressure retains the film in contact with the surface of the water, and thereby prevents the film from being whipped in the Wind. In another embodiment, the interior of the reservoir is maintained at an elevated pressure so that the sheet bellows out. This also reduces the tendency of the film to be whipped in the wind, The pressure control within the reservoir can conveniently be accomplished by the use of suction or blowing devices which are actuated by the wind.

Accordingly, it is an object of this invention to provide an improved, low cost system for storing surface water.

Another object is to provide an eflicient method of collecting and storing surface water in windy, arid regions.

Other objects, advantages and features of the invention should become apparent from the following detailed description, taken in conjunction with the accompanying drawing in which:

FIGURE 1 is a view, shown partially in section, of a first embodiment of the storage system of this invention. FIGURE 2 illustrates a second embodiment of the pressure maintenance feature of this invention.

Referring now to the drawing in detail and to FIGURE 1 in particular, there is shown a reservoir 10 formed in the surface of the earth. Such a reservoir can be formed by the use of a bulldozer or other dredging device, and is located in an area to collect water which flows along the surface following a rain. Reservoir 10 is surrounded by a dike 11 which defines the outer contour of the reservoir.

One or more filling pipes 12 can extend through the dike to permit the reservoir to be filled from the watershed area. These pipes can be provided with suitable inlet screens 13 to prevent debris from clogging the pipes.

The base of reservoir 10 is preferably lined with a water impermeable material 14 to prevent loss of water into the soil. Various materials can be employed for this purpose. For example, roofing material or felt mats formed of synthetic or natural fibers impregnated with asphalt can be used to advantage in many areas. Liner 14 can also be formed of a flexible synthetic material, such as rubber or plastic sheeting. If the reservoir is to be formed in soil which is relatively impermeable, this liner is not needed. However, in most arid regions a liner is necessary. The liner can be anchored at its ends to dike 11 by any suitable means. In order to prevent evaporation of water from reservoir 10, a cover 15 is positioned across the top of the reservoir. This cover is made of a relatively thin flexible material, such as polyethylene film. The edges of cover 15 are also anchored in dike 11 so as to cover the reservoir completely. A delivery pipe 16 extends from reservoir 10 through dike 11 to a stock tank 17 or other point of water usage. A valve 18 is provided in pipe 16 to control the withdrawal of water from reservoir 10.

As previously mentioned, it is desirable from an economic viewpoint to use a relatively thin, flexible material for cover 15. However, this poses problems because the cover is likely to be damaged by wind. In order to avoid this problem, the pressure above the water in reservoir 10 is adjusted to minimize movement of cover 15. As illustrated in FIGURE 1, a pipe 20 extends through dike 11 to a region above the surface of the water in reservoir 10. The inner end of pipe 20 is provided with guard rods 21 to keep cover 15 from closing the pipe. The outer end of pipe 20 is provided with a rotary turbine ventilator 22 to increase the draft provided by pipe 20. In this manner, wind blowing across the top of the reservoir tends to evacuate the interior of the reservoir. The resulting pressure reduction forces cover 15 against the surface of the water and thereby prevents the cover from whipping in the wind. An advantage of this system resides in the fact that any increase in wind velocity results in a corresponding decrease of pressure within the reservoir to hold cover 15 more tightly against the surface of the Water. While any means for evacuating the interior of the reservoir can be employed, the ventilator is advantageous because it is inexpensive to construct and does not require any appreciable amount of maintenance.

A second embodiment of this invention is illustrated in FIGURE 2. In this embodiment, the pressure reducing means of FIGURE 1 is replaced by apparatus which increases the pressure within the reservoir. To this end, a pipe 20' extends through dike 11 in substantially the same manner as does pipe 20 of FIGURE 1. However, the upper end of pipe 20' is provided with a rotatable wind scoop 25 which faces into the wind because of an attached weather vane 26. Air scoop 25 results in the passage of air into the region 23 above the surface of the liquid so that cover 15 bellows upwardly. In this manner, cover 15 tends to remain in a relatively stationary position so that wind damage is minimized. In this embodiment, pipe 20' is normally positioned within a region of dike 11 upstream of the reservoir in the prevailing wind.

In view of the foregoing description, it can be seen that an efficient, economical reservoir is provided in accordance with this invention. While the invention has been described in conjunction with presently preferred embodiments, it should be evident that it is not limited thereto.

What is claimed is:

1. A reservoir for liquids comprising:

means forming a chamber adapted to hold a liquid to be stored, said chamber normally being open at the p;

a gas impermeable cover extending over said chamber and sealed to the edges thereof, said cover being formed of a flexible material; and

means communicating with the interior of said chamber to change the pressure inside said chamber above the liquid being stored, thereby tending to displace said cover relative to the surface of liquid being stored in said chamber, said means to change pressure comprising conduit means extending from the interior of said chamber above the surface of liquid being stored to a region, exterior of said chamber, and

gas transfer means connected to said conduit means to pass gas therethrough to change the pressure above the surface of liquid in said chamber.

2. The reservoir of claim 1 wherein said gas transfer means comprises means to pass gas through said conduit means to said exterior region to reduce the pressure within said chamber above the surface of liquid being stored so that said cover tends to be forced downwardly into engagement with the surface of the liquid.

3. The reservoir of claim 1 wherein said gas transfer means comprises means to pass gas through said conduit means to the interior of said chamber to increase the pressure within said chamber above the surface of the liquid being stored so that said cover tends to be forced upwardly away from the surface of the liquid.

4. The reservoir of claim 1 wherein said chamber is formed in the surface of the earth and further comprising:

second conduit means extending from the interior of said chamber to the exterior thereof at a region adjacent the surface of the earth to collect surface water and pass same into said chamber; and

third conduit means extending from the interior of said chamber to the exterior to permit withdrawal of water from said chamber.

5. The reservoir of claim 4, further comprising a water impermeable liner covering the surface of the earth forming the bottom of said chamber.

6. A reservoir for water comprising:

a chamber formed in the surface of the earth so as to be open at the top;

a cover formed of flexible material extending over said chamber and sealed to the edges thereof;

first conduit means extending from the interior of said chamber to the exterior thereof at a region adjacent the surface of the earth to collect surface Water and pass same into said chamber;

second conduit means extending from the interior of said chamber to the exterior to permit withdrawal of Water from said chamber; and

means to change the pressure inside said chamber above the surface of water being stored, comprising third conduit means extending from the interior of said chamber above the surface of water being stored to a region exterior of the chamber, and a ventilator secured to said third conduit means to Withdraw air from the interior of said chamber through said third conduit means so as to reduce the pressure within said chamber and thereby tend to force said cover downwardly into engagement with the surface of the liquid.

7. The reservoir of claim 6, further comprising a water impermeable liner covering the surface of the earth forming the bottom of said chamber.

8. A reservoir for water comprising:

a chamber formed in the surface of the earth so as to be open at the top;

' second conduit means extending from the interior of said chamber to the exterior to permit withdrawal of water from said chamber; and

means to change the pressure inside said chamber above the surface of water being stored, comprising third conduit means extending from the interior of said chamber above the surface of water being stored to a region exterior of the chamber, and an air scoop secured to said third conduit means to pass air into the interior of said chamber through said third conduit means so as to increase the pressure within said chamber and thereby tend to force said cover upwardly out of engagement with the surface of the liquid.

9. The reservoir of claim 8, further comprising a water impermeable liner covering the surface of the earth forming the bottom of said chamber.

References Cited UNITED STATES PATENTS 2,211,958 8/1940 Mahatfey 6l.5 X 3,052,380 9/1962 Prins 6l.5 X 3,330,118 7/1967 Biais 6l.5 3,425,791 2/1969 Koberg 6l.5 X

PETER M. CAUN, Primary Examiner