Safety Tank Apparatus for Liquid Storage Having Fire Resistant Construction

There is great and continuing need for environmentally safe, fire resistant, easily shipped, and readily installable and usable containment systems for flammable liquids and contaminants. Such systems should be fireproof insofar a possible. I am not aware of any presently available system having the usual advantages in construction, modes of operation and results, as afforded by the present invention, as well as meeting the above needs.

It is a major object of the invention to provide an improved system meeting the above need, as well as providing additional advantages in construction and mode of operation. Basically, the safety tank or system of the invention comprises:

a) structure including first and second inner metallic tanks, and an outer metallic housing protectively receiving the inner tanks, the outer housing having a side wall, there being upper interior space above the inner tanks and within the housing, the second tank located within the first tank,

b) the housing including a cover extending over the inner tanks,

c) an opening in the side wall, and a closure closing the opening, the closure movable to expose the upper interior space to access from the exterior,

d) and control means below the cover, and accessible through the opening for controlling flow of the liquid into the second tank from the exterior of the safety apparatus.

As will appear, the inner tanks are enclosed, and when the cover is located on the housing and its side wall closure is closed, weather is excluded from the upper interior space below the cover, and above the inner tanks, so that the control means is protected, as well as space between the side walls of the housing and inner tanks, and space below the inner tanks. That space may be vented. In addition, space between inner tanks may contain fire-resistant material. Enhanced fire protection is also thereby provided, the outer housing also offering protection, as from contaminant liquid leakage to the exterior of the inner tanks. Such leakage might for example occur due to inadvertent handling of the hose or line connection to a liquid pump, or handling of other closures for bungs in the top cover of the inner tank.

Another object is to provide a way to convert a waste oil storage tank to a fuel supply tank.

It is a further object of the invention to provide for access to pump means having a liquid intake port and a delivery port, the delivery port communicating with the interior of one inner tank, and a pneumatic fluid control valve connected with the pump drive for controlling pressurized drive fluid flow to the pump drive. The valve has associated means for sensing the level of liquid in the one inner tank, and for closing the valve in response to rising of the liquid surface to a predetermined level. Also an audible alarm may the be activated. In this regard, the structure above the inner tanks and below the cover typically has an upper or top wall that supports the pump and valve to be directly accessible via the opening in the closure side wall.

Another object includes provision of means to control inflow of liquid into an inner tank in response to liquid level changes in the inner tank and also within a safety space surrounding the inner tank.

Additional objects include the provision of a first aperture in the upper wall, as defined, via which liquid in the inner tank may be removed by a duct extending below the inner tank top wall; and the provision of a second aperture in the top wall for venting air from the inner tank as liquid is filled into the inner tank by operation of the pump. These elements, as well as others, are easily accessed when the closure or door in the side wall of the top closure is opened. Multiple tank combinations may also be provided.

These and other objects and advantages of the invention, as well as the details of an illustrative embodiment, will be more fully understood from the following specification and drawings, in which:

FIG. 1 is a perspective view showing a system in accordance with the invention;

FIG. 2 is a section taken in elevation through the system of FIG. 1 to show interior construction;

FIG. 3 is an enlarged section taken in elevation on lines 3--3 of FIG. 2;

FIG. 4 is a schematic view of an air (pneumatic fluid) valve control mechanism;

FIG. 5 is a schematic showing of automatic means to control inflow of liquid to the inner tank;

FIG. 6 is a front elevation of a modified multi-tank unit;

FIG. 7 is an end elevation taken on lines 7--7 of FIG. 6;

FIG. 8 is a front elevation showing interior construction of the FIG. 6 unit;

FIG. 9 is a front elevation of another modified multi-tank unit;

FIG. 10 is a front elevation showing interior construction of the FIG. 9 unit;

FIG. 11 is an end elevation taken on lines 11--11 of FIG. 10;

FIG. 12 is a side elevation showing interior construction of the FIG. 9-11 unit;

FIG. 13 is a front elevation of yet another modified tan construction;

FIG. 14 is an end elevation taken on lines 14--14 of FIG. 13;

FIG. 15 is a front elevation of the FIG. 13 unit, broken away to show interior construction;

FIG. 16 is an end elevation on lines 16--16 of FIG. 15;

FIG. 17 is a front elevation, broken away, to show interior construction of the inner tank of the FIG. 13 unit;

FIG. 18 is a top plan view taken on lines 18--18 of FIG. 17;

FIG. 19 is a view like FIG. 2 showing a modification;

FIG. 20 is a fragmentary view showing three inner tanks;

FIG. 21 is an elevation showing a further modification; and

FIG. 22 shows roller support of the FIG. 21 tank structures.

In FIGS. 1-3, the safety tank apparatus 10 includes an inner metallic tank 11, which is closed, and an outer metallic tank 12 protectively receiving the inner tank. The outer tank is upwardly open and has a removable top or cover 24 so that the inner tank may be lowered downwardly into the inner tank to be supported by spaces 14 located between the bottom wall 15 of tank 11 and the bottom wall 16 of tank 12. Likewise, feet or spacers 17 support the bottom wall 16 on the ground or pavement 18. Feet 17 are channel shaped to receive the tines of lift trucks or the like. Also, the feet allow visual inspection of the bottom of the outer tank.

The inner tank has a side wall or walls 19 which extend upright in inwardly closely spaced relation from the side wall or walls 20 of the outer tank. While various tank configurations are possible, each tank preferably has four walls, whereby inner tank 11 has maximum capacity. See space 21. All tank walls are typically metallic (thin steel sheet, for example) and walls 19 and 20 extend upright. The inner tank is closed by a metallic top wall 22, generally near but below the level of lower hinge 31a of a closure 31 for a side opening 30 in an upright wall of the outer tank, for lateral accessibility of controls mounted on that top wall 22, as will appear. Such controls are generally designated at 23. Note brackets 185 connecting walls 20 to top wall 22 to position the inner tank in the outer tank.

Cover 24 extends over the inner and outer tanks 10 and 11 to protect the controls 23 and secondary containment spaces 21 and 35. That cover 24 has a top wall 25 spaced above inner tank top wall 22 (see space or interior 26), and side wall or walls indicated at 27. The latter are removably attached to the outer tank side walls, as at 27a, rigidizing the overall assembly, and preventing any unauthorized entry into space 26, as well as access to controls 23. Cover 24 may be square in outline, as shown, or have other configuration.

As referred to, the closure 31 (lockable at 31c) is hinge attached to the outer tank front wall to be movable, i.e, openable for example on hinge or hinges 31a, to expose the space or interior 26 of the cover, thereby providing direct access to the controls, without having to lift or raise the top cover 24. Also, opening of the closure allows downward visual inspection of spaces 21 and 35. At the same time, the cover always provides protection for the controls, as against adverse weather, vandalism, impacts, fire, etc. Also, with the closure 31 normally closed, outside air (i.e., oxygen) is sufficiently excluded from access to the interior 26, for minimizing risk of fire at the controls, and to exclude access of exterior flames to the controls and to the inner tank. Some air circulation is provided by louvered vents at 198.

The controls or control means 23 are so located, due to the construction and interfitting of the tanks 11 and 12 and the cover 24, as to provide direct lateral access to the controls via the opening 30, when the closure 31 is open. As shown, the controls are carried on the top wall 22 of the inner tanks so that any liquid spillage will drain downwardly into the narrow space between the tanks 11 and 12, to the bottom spaces 21 and 35. Liquid leaking to or otherwise collecting in spaces 21 or 35 may be removed as by a suction line.

Referring to FIGS. 3 and 4, the control means is shown to include a pump and pump motor unit 40, the pump having an intake port 47 for in-flowing waste liquid, and a discharge port 41 for that liquid. Unit 40 may be of double diaphragm, reciprocating type. Port 41 is connected via permanent line 42 and fitting 42a and 42b with a pipe or duct 42b extending vertically from a port 42a in top wall 22 downwardly to a discharge point 42c near bottom wall 15, whereby waste liquid pumped into the tank system is delivered into the inner tank. A single hose may connect between the top of 42b' and port 41. Pipe 42b' is metallic, and extends close to the bottom of the tank to eliminate static electricity build up. See also line or duct 44 extending from waste liquid collection unit or caddy 43 (as used at oil-change stations) to the pump intake line 45 in space 26. Line 45 extends from a connection at 46 to wall 20 via knockout 20a to the pump intake port 47. Duct 44 may be attached endwise to line 45 at the connection 46.

Likewise, a line 48 from a source 49 of pressurized air passes through upright wall 20 via knockout 20b and leads to a valve 52 near the pump. The valve is in turn connected at hose 53 to the pump motor air intake regulator 54a, which is in turn connected to pump motor air intake port 54. Thus, the pump may be air motor driven, for safety. Exhaust air is vented to space 26. An air supply control valve appears at 58 to control operation of the motor. Overflow liquid from the pump passes via port 40a, fitting 40b, and through line 40c and through a cap 40e of emergency relief vent 40d to drain into the inner tank. If excess pressure builds up in the inner tank, it is released by blow off of cap 40e.

Valve control means is provided for sensing the level of liquid in the inner tank, and for automatically closing the valve 52 in response to rising of the top level 60c of waste liquid 60 in the inner tank to a predetermined level, as for example to about 95% of full level in the inner tank. Also, the valve by-passes incoming air to a relief port 52a providing an audible alarm to indicate that level 60c has reached the predetermined level. An air activated alarm device, such as a whistle 52a', can be located on or associated with 52a. Such control means is shown in FIG. 4 to include a float 64 in the inner tank, and floating in or on the waste liquid. A stem 66 connects the float to a rotating disc-type stopper at location 67 in the valve, to seat or close the stopper when 95% level is reached, thereby shutting off compressed air supply to the pump motor. Note parallelogram linkage arms 90 and 91 slidably connected with vertical link 92, attached to stem 66. Also note counterweight 94.

Liquid may be removed from the filled tank by unlocking and opening the access door 31, and by connecting a removal line 70 to a connector 70a on stand-pipe 70a in take 11, and via a top opening 22e in wall 22, and a connection at 70b, pipe 70a normally closed by a cap 71 in space 26. Line 70 may be extended through the opening 30 in the outer tank side wall 20 when the closure 31 is opened. See FIG. 3. Other openings, with appropriate plugs, may be provided in top wall 22, as for example normal and emergency vents, to vent air and fumes from the upper tank as it is filled with liquid, etc. See vent pipe 165 and opening 165a to the inner tank. Pipe 165 passes through the opening provided by knockout 20c.

As noted, the system does not require any electricity, all components being mechanical.

Site level gauge 166' may be located next to the air shut-off valve, to indicate the remaining fill capacity of the inner storage tank. It is viewed via port or window 169 in closure 31. Port 169 has a covering of clear material, such as plexiglass, to provide for visual inspection of level gauge 166 without opening closure 31, and to keep weather and excess air out of spaces 21, 35 and 26.

When transferring liquid to the storage tank, the operator first looks at the site gauge to determine the existing fill capacity of the tank to see if transfer is possible, or if pick-up is needed. Second, the suction hose 44 is coupled to the collection caddy 43 and the air source is turned on, as by opening valve 58. When the collection caddy is emptied, the hose 44 is disconnected, and then the air is turned off at valve 58.

If the automatic shut-off valve 52 closes during transfer of liquids into the storage tank 11, the predetermined maximum fill level has been reached. The valve 52 will bypass air from 40 to an audible air alarm 52a which can be located inside the enclosure or remotely. The pump motor will then remain inoperable until the liquid in the tank has been lowered below a predetermined level.

If at any time the site gauge 166 indicates the liquid level is near maximum fill capacity, or the automatic shut-off valve engages, the operator should contact a waste oil hauler to schedule a pick up.

When emptying the inner storage tank, the first step is to unlock the environmental closure 31 (normally locked at 31c) and open it so that the control assembly area is accessible. Second, a visual inspection of spaces 21, 35, and 26 should be conducted. Third, suction hose 70 from the truck should be connected to the coupler at connector 70a' after removing the cap 71. Fourth, when disconnecting the suction hose, the suction should remain "on" so the liquid remaining in the hose empties completely into the removal truck. Fifth, place the cap 71 back on at 70a', and conduct another visual inspection of spaces 21, 35 and 26. Sixth, the environmental closure 31 should be closed (or lifted) back into place and locked.

Space 26 is vented at openings 198 in side wall 20.

Drainage of inadvertently spilled liquid in space 26 can occur off top wall 22 into spaces 21 and 35, as referred to, for safety.

In FIG. 5, elements the same as in FIGS. 2 and 4 bear the same numerals. Control means is provided for automatically effecting flow of liquid (hydrocarbon, for example) as via line 45 and pump 40, into the inner tank, from the exterior of the safety apparatus if the level of liquid in the inner tank drops below a predetermined level (see level 160); the control means also prevents flow of each liquid into the inner tank if the level of liquid rises to or above a predetermined upper level (see level 161). Such control means includes, for example, a valve 52 via which pressurized motive fluid (air, for example) flows via line 53 to the pump 40 operating to pump liquid via lines 45 and 42b into the inner tank, and a first float 64 for sensing the actual surface level of the liquid 60 in the inner tank. If the liquid level rises to 161, the float is elevated to a position to close valve 52, and if the level drops to 160, the float is lowered to a position to open valve 52. Other equivalent means may be employed.

Also provided is other control means for automatically preventing inflow of liquid into the inner tank if the level 165 of liquid in space 21 is above a predetermined level, as at 170. This provides an additional safety feature in that, if the inner tank leaks to space 21, and sufficient liquid flows into that space, no further liquid will be passed into the inner tank. Note for example that such other control means may include a valve 152, like valve 52, and in series therewith via motive air pressure line 153. If the level of leaked fluid in space 21 rises to 170, the float 172 in space 21 also rises, causing a link 166 to close the valve 152, stopping the pump 40. Liquid in space 21 may then be sucked or pumped out, as at 174; and the float 172 then drops to open valve 152 and allow resumption of operation of pump. Equivalent structure may be provided.

Accordingly, in the example shown, the pump is controlled by automatic operation of either of the valves 52 or 152 by means of sensors sensing liquid levels in inner tank, and in the safety space 21 surrounding the inner tank.

FIGS. 6-8 show a multiple tank assembly in a single unit. The outer tank 212 (corresponding to tank 12) is elongated to receive two like inner tanks 211, each of which corresponds to tank 11. Equipment is mounted on the top wall of each inner tank, and corresponds to the equipment discussed in FIGS. 1-5. The same identifying numerals are used to identify the item of such equipment.

The outer tank front wall panel 220a is of a length to accommodate the two inner tanks between outer tank end wall panels 220b, and also between front and back panels 220a and 220c. Two closures 231 (like closure 31) are hinge attached at 232 to the front wall to be movable, i.e., openable to expose the equipment mounted on the inner tank top walls 222. Note also the locks 231c for the closures, and the ports 269 in the closures via which oil level indicators 280 are visible. Note the spillage and leakage receiving spaces 221a between the inner tank upright walls, and the outer tank upright walls; the spillage space 221b between the two inner tanks, and the bottom space 235, corresponding to space 35. See also feet or spaces 214 and 217.

Associated with an outer tank end wall panel 220b are: louver vents 298, working vent (knock out) 301, air pressure line inlet (knock out) 302; and suction line inlet (knock out) 303. A working vent pipe elbow, with cap, is indicated at 304. Both inner tanks may be used to receive waste oil, as at vehicle filling stations, truck stops, and the like. Other fluids, such as new oil, etc., may be similarly handled.

FIGS. 9-12 are like FIGS. 6-8 in that the outer tank 312 encloses or receives two like inner tanks 311a and 311b. The latter are spaced apart front-to-rear, relative to the front side or wall panel 320a of the outer tank. Accordingly, the two inner tanks have left to right length (see FIG. 10) about the same as, but slightly less than, the left-to-right length of the outer tank. The two inner tanks are in intercommunication, as via a duct or pipe 380 seen in FIG. 12, as located near the bottoms 316 of the two inner tanks or the like. Accordingly, only one set of operating equipment is used, at the top of the inner front tank 311a. This is accessible via end closure 331, like one of the closures 231 referred to above. Two outer tank rear wall panels 320c and 320c' are provided, panel 320c located rearwardly of rear inner tank 311b, and panel 320c' located above the level of panel 320a, and forwardly thereof as an offset (in FIG. 11) to close the equipment space 326. See also outer tank side panels 322 and 323, and top walls 324 and 325.

FIGS. 13-18 again show a sidewardly elongated outer tank 412, having a single closure 431 via which access is gained to a single equipment set, as in FIGS. 1-5. The latter equipment is mounted on top wall 422 of a single inner tank 411, which is also elongated, left to right, as is clear from FIGS. 15 and 17. FIG. 17 shows interior construction of the inner tank. Thus a single, enlarged, inner tank is provided. FIG. 18 shows the position of:

pump base 486 on wall 422.

suction line port 487 on wall 422

sight level port 488 on wall 422

working vent port 489, in 422

emergency evacuation vent port 490 in 422

shut-off valve mounting flange 491 on 422.

FIG. 19 is a view generally like FIG. 2 but showing a modification. Elements in FIG. 19, the same as in FIG. 2, bear the same numerals. The outer metallic tank 12 may be considered to represent a metallic housing. Within that housing are first inner metallic tank 11 (as before) and second inner metallic tank 511. The latter is surrounded or enclosed by the former, and space 550 therebetween (at all sides as well as at the top and bottom) is filled with fire-resistant (or fireproofing) material 550a, examples being FENDOLITE (which is a mixture of vermiculite and Portland cement) or lightweight foam concrete, which is pumped int the space and cured in situ. The second inner tank 511 functions to store liquid hydrocarbon (for example fuel, waste oil, or anti-freeze) in the same manner as tank 11 in the FIG. 2 configuration; however, the encapsulation or enclosure of storage tank 511 in FIG. 19 by fire-resistant material (held in place by tank 11) significantly enhances the fire safety and bullet resistivity of the equipment, which is typically installed and operated aboveground. Note that ducts 70a and 42b' extend downwardly through the top walls 22 and 522 of both inner tanks.

The inner tank side walls are indicated at 523 and 524, and bottom walls at 15 and 515 with spacings therebetween as indicated. Supports between walls 15 and 515 are indicated at 535. All walls typically consist of thin sheet steel.

In FIG. 20, an additional or third metallic tank 611 is located between first and second tanks 11 and 511. Tank 611 is encapsulated by tank 11 and everywhere spaced therefrom; and tank 511 is encapsulated by third tank 611 and everywhere spaced therefrom. The fire-resistant material 550a, as referred to above, is here located or filled into or in space 550' between tanks 611 and 511. Space 550'', between tanks 611 and 11, is left free of such material, but may also contain such material to fill the space for additional fire resistance.

In both FIGS. 19 and 20, the float 564 is supported by an arm 566 that swings as the level of the liquid 60 in the inner most tank rises or falls. Note pivot location 66a, associated with valve structure 552 which controls inflow of pneumatic fluid via lines 48 and 53, to pump apparatus 40. When the float arm 566 swings to broken line position 566', the valve apparatus shuts off the pneumatic fluid flow to the pump; and when the arm swings to full down position, due to lowering of liquid level 60c, the valve apparatus opens to pass fluid to the pump.

Also shown in FIG. 19 is a means whereby the outer tank 11 (containing inner tank 511) may be installed in the housing 12, and supported laterally therein. See laterally extending brackets 580 attached to the top wall 22, with tongues 581 that fit downwardly into receptacle brackets 582 attached to the inner sides of the housing walls.

In FIG. 21, elements corresponding to those shown in FIG. 19 bear the same numbers, the units being generally alike and incorporating the same elements

Note, however, the following: heavy duty L-shaped brackets 320 have upright 321 engaging or adjacent walls 11, and horizontal extents 322 engaging the upper side of bottom wall 16, to prevent shifting of tank 511 relative to tank 11. Bracket extents 322 also have edges 322a fitting against walls 20. Elements 580, 581, and 582 may therefore be omitted. The outer tank 12 is stabilized against lateral shifting, as by L-shaped brackets 324. The latter have uprights 325 adjacent the outer sides of walls 20, and lower horizontal extents 326 attached, as by heavy duty bolts 327 to a concrete or other pad 328. Need for associated berm structure about the tank assembly is thereby eliminated.

An air pressure regulator is provided at 54a, in series with line 48, and a whistle alarm at 52a', as before. Tank 11 is here acting as a containment sleeve, and has a removable lid or cover 322b, which is removable from walls 11 to provide downward access to space 388 between 11 and 511. After fire resistant material 550a is filled into space 388, lid 322b is applied, to the position shown. It has openings at 589, 590 and 591 to pass pipes 70a, 42b, and valve structure 552. Fire resistant blocks, such as refractory bricks, may be located at positions 14 and 535. Fire resistant flowable material 550a, such as FENDOLITE (vermiculite and foamed concrete in aqueous mix) or lightweight foamed concrete, is pumped or poured into the space 388 between tanks 511 and 11 to fill such space about tank 511, and allowed to cure in situ. Likewise, fire resistant blocks, such as refractory bricks 594, may be placed between 11 and 511, as shown to block lateral shifting of inner tank relative to tank 11. The thickness dimension "d" between walls 20 and tank 11 may be easily increased by providing a larger outer tank or cabinet 12, as may be required by environmental standards. All tanks and their walls are made of thin steel sheets and are transportable to a selected site or sites.

An air-line water trap may be installed at 599, in series between 58 and 49.

FIG. 22 shows the use of rollers 577 and roller supports 577a beneath bottom wall 16 to support the FIG. 21 tank and cabinet structures, like those of FIG. 21. Such rollers allow limited lateral travel of the tank assembly, as during an earthquake.

Vermiculite has the following typical range of chemical analysis:

Finally, FIG. 21 shows a side receptacle 420 attached to wall 20 of the housing to receive in-pouring of liquid (waste oil, for example) when lid 421 is lifted. See lid hinging at 422. Such liquid may pass through a strainer screen 423 in the receptacle, that excludes larger particles or pieces, and then drains at 424 to a pump 425. The latter pumps the liquid into inner tank 511, as for example via line 48.