FUEL TANK PROCESS AND WASHER Field of Invention The present invention falls into the class of devices for washing and cleaning of metal products-fuel tanks and other containers. The subject matter of this invention is a transportable washer suitable for washing and cleaning of both fixed and portable fuel tanks-containers and falls into the sub-group C 236 5/04 of the International Patent Classification.

Technical Problem The technical problem resolved with this invention involves the structure of this device. Its technical features make this device suitable for: - Washing and cleaning of a wide range of fuel containers, from small ones (cans, drums) to tank trucks and large underground tanks; - Separation (while washing) of the mixture components (fuel, water, sludge) resulting in a considerable fuel saving.

- While washing, the operator does not stay inside the tank.

- Environmentally friendly washing operation.

- This device is an adequate substitute for similar imported devices and its manufacturing costs are very low as compared to the cost of such imported devices.

Spare parts as well as repair and maintenance services are available.

State of the Art Fuel tank washing and cleaning operations, both in Croatia and worldwide, have mostly been performed manually. Such manual washing and cleaning have various disadvantages, in particular: - Poor washing quality and high fuel loss because the fuel is not separated from water and sludge.

- The operator works inside the tank wearing a mask under conditions that have a harmful effect on his health and result in low performance.

- Manual washing causes environmental pollution.

- In addition to many other drawbacks, imported units (from Germany etc. ) are too expensive.

For imported units, the spare part supply is inadequate and the maintenance and repair services are not available.

Brief Description of Drawings The invention is illustrated with the enclosed drawing (Fig. 1) showing the structure of the"Dada"fuel tank washer, in particular: (1) corresponds to the hot water producing unit (2) corresponds to the high pressure pump (3) corresponds to the main control cabinet (4) corresponds to the power generating set (5) corresponds to the fuel tank (6) corresponds to the detergent tank (7) corresponds to the hydrant (8) corresponds to the collector tank (9) corresponds to the hose reel (10) corresponds to the gun for manual washing (11) corresponds to the support for small containers (barrels, drums, cans) (12) corresponds to the washing head for interior washing of truck tanks (13) corresponds to the support for a large tank washing head (14) corresponds to the large tank washing head (15) corresponds to the self-propelled trolley for small tank washing (16) corresponds to the small tank washing head (17) corresponds to the sludger for the mixture (fuel, water, sludge) (18) corresponds to the super centrifuge (19) corresponds to the fuel drum (oil, petrol) (20) corresponds to the collector tank (8) filter (21) corresponds to the high pressure hose (22) corresponds to the high pressure hose (23) corresponds to the mixture (water, sludge, fuel) suction hoses (24) corresponds to the tank-sludger interconnecting hose (25) corresponds to the fuel tank (5) filter (26) corresponds to the switch in the collector tank (8) (27) corresponds to the switch that turns the pump (17) on when the tank is empty

(28) corresponds to the switch that turns the pump (17) off (29) corresponds to the mixture (water, sludge, fuel) tank (30) corresponds to the water discharge valve (31) corresponds to the decanter-centrifuge (32) corresponds to the sludge tank (33) corresponds to the sludger II (34) corresponds to the mixture (water-fuel) pump Brief Functional Description of the"DADA"washer This unit operates on the following principle: The hot water producing unit (1) produces a required quantity of water at 150°C and, by means of the high pressure pump (2) having an output of 6300 1/h, the water pressure of 120 Bar is achieved.

The fuel (light oil) is supplied to the burner installed in the cleaning plant from a 350 1 fuel tank (5) placed on a vehicle. The hot water is pumped through the high pressure hose (21) to the interior washing heads (11,12, 14,16) of the gun (10) and to special self-propelled trolley (15). The water degreases and washes the tanks, truck tanks and other containers. After the washing, a sludger (17) having an output of 65001/h is put into the tank, which pumps the mixture (sludge, water, fuel) through the hose (23) and delivers it to the tank (29). The tank (29) is furnished with the switches (27,28) designed to: 1. Switch the sludger (17) on when the tank (28) is filled-up 2. Switch the sludger (17) off when the sludger II (33) has pumped out all mixture (water, fuel, sludge) from the tank (29).

The sludger II (33), having an output of 24001/h, pumps the mixture (water, fuel, sludge) from the tank (29) into decanter-centrifuge (31). The on/off switching of the sludger II (33) is performed manually. The sludger II (33) is switched on when the sludger (17) starts to fill the tank (29) and is switched off when all the mixture (water, fuel, sludge) has been pumped out from the tank (29). The decanter (31) separates the sludge from water and fuel. The output of the decanter-centrifuge is 2400 1/h. The sludge is then discharged into the sludge tank (32), the mixture (water, fuel) is recirculated into the system, while the sludge is neutralized and safely disposed without any risk of environmental

contamination. The decanter-centrifuge (31) is switched on simultaneously with the sludge pump II (33).

The mixture (water, fuel) is pumped from the decanter-centrifuge (31) by means of the pump (34) and delivered to the super-centrifuge (18) having an output of 2400 1/h, where the heavier liquid is separated from the lighter liquid, i. e. petrol/oil from water in this particular case. The petrol/oil is discharged in drums for further use and the waste water is either recirculated into the process through the collector tank (8) or discharged in the environment without any risk of environmental contamination.

Application of Invention First of all, the"Dada"washer may be used in the oil industry worldwide, in particular by all those involved in the transport, use and storage of oil and oil products, for the washing of truck tanks, underground tanks at filling stations, various fuel storage tanks from 1000-5000 m3 and over, small containers (cans, drums) etc.

This washer is fully transportable and may be taken to any location where the cleaning-washing of a fuel tank is required. All component parts of the washer are preassembled in a container which is mounted on the body of a car or trailer. When out of use, the container is removed from the truck with adequate lifting equipment, so that the truck may be used for other purposes.