Oil transfer system

A hazardous fluid removal and storage apparatus for the fail-safe removal and storage of hazardous liquids. An electrically monitored and electro-pneumatically controlled system provides safe pumping and storage of hazardous liquids with automatic pump shut-down and warning signals for leak detection and full storage tank conditions.

BACKGROUND OF THE INVENTION 
The present invention relates to a waste oil removal apparatus and, more 
particularly, relates to a fail-safe apparatus for removal and storage of 
hazardous liquids. 
The transfer and storage of waste oil or like hazardous liquid has resulted 
in environmentally dangerous spills. It is known to place a limit switch 
in a storage tank to indicate full capacity and it is also known to 
provide a containment means in the event of a leak. However a faulty 
switch or a poor connection from the switch to the control panel may 
result in a spill situation. 
It is an object of the present invention to provide an apparatus for the 
fail-safe removal and storage of hazardous liquids. It is desired that the 
system be fail-safe in that pumping will cease in the event of a leak 
detection in a storage tank or upon filling the storage tank to capacity. 
Also it is desirable that the system be provided with visual and audio 
modes for the reliable identification of full (i.e. 95% full) or leaking 
conditions. 
SUMMARY OF THE INVENTION 
The hazardous liquid removal and storage apparatus of the present invention 
comprises an air operated pumping means operatively connected at its 
suction port to a hazardous liquid container, at its discharge port to a 
storage tank, and at its air supply port to an electrically operated 
solenoid valve; and an electrical control circuit connected in series 
comprised of a tank leak indicator switch, located in the containment 
tank, an ON/OFF switch, an electrically operated solenoid valve and a 
storage tank full switch located in the storage tank. 
In a more specific embodiment, a signal light is connected in parallel to 
the series control circuit to indicate sufficient power supply, a warning 
circuit having visual and audio signalling means is connected in series 
with the full storage tank switch, and a second warning circuit having 
signalling means is connected in series with the tank leak indicator 
switch. 
In its broad aspect, the hazardous liquid removal and storage apparatus 
comprises, in combination an enclosed liquid storage tank, an enclosed 
containment tank in which the storage tank is placed, a liquid container 
for receiving hazardous liquid fluids to be disposed, an air-actuated 
liquid pump in communication with the liquid container and the storage 
tank for transferring liquid from the liquid container to the storage 
tank, a pressurized air supply for actuating the liquid pump, and an 
electrically energized solenoid actuated valve in the air supply for 
controlling the flow of air to the pump, and a leak detector sensor in 
said containment tank and a tank full sensor in the storage tank in a 
normally-closed series-connected control circuit in electrical series with 
the solenoid-actuated valve for normally actuating the solenoid valve to 
permit the flow of pressurized air to the liquid pump for actuation of the 
pump whereby sensing of a leak by the leak detector or sensing of a full 
tank by the tank full sensor will open the said series connected control 
circuit to de-energize the solenoid and stop the flow of air to the pump 
to cease the transfer of the liquid liquid.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
With reference to FIG. 1, a hazardous liquid, such as liquid crankcase oil 
requiring disposal, is contained in a hazardous liquid container 12. An 
air operated pump 16, in communication with air supply line 21 via an 
electrically-operated solenoid valve 28 and air supply line 30, is 
employed to draw hazardous liquid from container 12 through a suction line 
14 and discharge said hazardous liquid to a storage tank 20 via discharge 
line 18. The storage tank 20 is positioned within a containment tank 22 as 
a precautionary means to contain any leaked hazardous liquid from said 
storage tank 20. 
Control panel 24 comprising a single-pole single-throw ON/OFF switch 44, a 
green power light 42, a red tank full light 46, a red leak detected light 
50 and an intermittent buzzer 48 is electrically connected to the 
electrically operated solenoid valve 28 housed therein, the 95% full 
proximity sensor 34, and the tank leak proximity sensor 36 through 
electrical conduit 32. 
Referring now also to FIG. 2, a schematic representation of the electrical 
circuitry of the present invention, a power source of 120 volt AC is 
received through a standard 120 volt AC male plug 38 and carried to 
control panel 24 shown in more detail in FIG. 1-A via lines 52 and 54, 
fuse 40 being connected in series in line 54 to protect the circuitry in 
the event of an electrical short. Power light 42, connected between line 
52 and fused line 55, will illuminate to confirm fuse 40 is intact and 
power is being received. 
Closing the ON/OFF switch 44, while normally-closed contact 58 of the 
single-pole double-throw tank leak proximity sensor 36 and normally-closed 
contact 60 of the single-pole double-throw tank 95% full proximity sensor 
34 are closed, completes the circuit 64 between line 52 and fused line 55 
and energizes the electrically-operated air solenoid 28, allowing air to 
flow to the air-operated pump 16 and the subsequent pumping of hazardous 
liquid to the storage tank 20. 
A parallel circuit 68 comprises normally-open contact 62 of the 95% full 
proximity sensor 34, located inside the storage tank, and a full tank 
indicator light 46. Sensing of liquid by the 95% full proximity sensor 34 
as the storage tank 20 nears capacity will open contact 60 of said sensor 
34 disrupting current flow through circuit 64 de-energizing electrically 
operated solenoid valve 28, thus terminating flow of hazardous liquid, and 
close contact 62 of said sensor 34 diverting current to flow through 
circuit 68 energizing full tank light 46. 
A second parallel circuit 66 comprises the tank leak proximity sensor 36, 
located at the bottom of the containment tank, connected in series with a 
parallel arrangement of the intermittent buzzer 48 and the leak detection 
light 50. Upon detecting escaping liquid in the containment tank 22, 
contact 58 of the tank leak proximity sensor 36 is opened terminating 
electrical flow to the electrically operated solenoid valve 28, thus 
ceasing the flow of hazardous liquid. Contact 56 is closed diverting 
current through circuit 66 energizing the intermittent buzzer 48 and the 
leak detected light 50 causing said buzzer 48 to sound and said leak 
detection light 50 to illuminate as warning of leak detection. 
The hazardous liquid removal apparatus of the present invention provides a 
number of advantages. The storage tank 95% full proximity sensor 34 and 
the tank leak proximity sensor 36 are arranged in series with the 
electrically operated solenoid valve 28 to provide an intrinsically safe 
circuit producing automatic pump shut-down in the event of a storage tank 
20 leak, a 95% full storage tank 20, or a poor electrical connection, 
sensor damage or sensor disconnection. The invention also provides visual 
and audio warning alarms concurrent with automatic shut-down due to leak 
detection and visual alarm upon 95% full detection as well as a visual 
indicator of power supply and fuse conditions. 
A switch may be connected between line 52 and line 66 and a second switch 
may be connected between lines 55 and 68 to allow for the testing of 
intermittent buzzer 48 and tank full indicator light 46 respectively. 
It will be understood, of course, that modifications can be made in the 
embodiments of the invention illustrated and described herein without 
departing from the scope and purview of the invention as defined by the 
appended claims.