21023 - Laboratory washer for fuel tanks

The laboratory washer is used to test the technical cleanliness of fuel tanks. It flushes out contaminants left inside the tank after production and collects them on a laboratory filter. The filter is then analysed for the amount and type of contamination.

Intended use of the machine

The machine is designed for quality control laboratories of fuel tank manufacturers and their suppliers. The tank is washed inside with a nozzle and outside with a spray gun. The alkaline washing liquid circulates in a closed circuit and is heated to the set temperature.

Description of operation

The washer works in three automatic cycle modes, selected with a switch on the control desk:

• WASHING: the operator selects the tank reference and starts the cycle. The washer heats the liquid in the reservoir, stabilises the temperature in the entire system and then carries out the main wash for the set time. Finally, the tank can optionally be rinsed with the gun. Suction can be switched on during washing;
• RINSING: the washer heats the liquid and rinses the tank with the gun;
• SUCTION: the washer extracts the liquid from the tank with the suction nozzle.

The operator confirms the successive cycle steps with a foot switch, leaving both hands free to handle the tank. If the liquid temperature drops below the minimum, the washer pauses washing and reheats the liquid. This guarantees repeatable test conditions.

Machine design

WASHING CHAMBER

The washing chamber has access doors and an extraction hood. The structure, including the frame and housing, is made of stainless steel.

PROCESS INSTALLATION

The installation includes:

• a 26 l liquid reservoir with a 2 kW heater;
• diaphragm pumps: supplying the washing nozzle, for suction, and generating vacuum in the filter circuit;
• a laboratory filter mounting assembly and filter unit;
• a valve terminal and pneumatically operated (NC) valves;
• a pressure reducer on the washing nozzle;
• sensors for temperature, minimum and maximum level, and pressure upstream of the filter and at the nozzle.

CONTROL SYSTEM

The washer is controlled from a desk with operating mode selection, CYCLE START/STOP buttons and alarm indication, and from an HMI operator panel. The recipes (references) store the liquid temperature, washing time and pressure warning thresholds. The process screen shows temperatures, pressure and the time remaining until the end of washing. The panel also has pages for manual movements, sensor status and alarm history.

Safety level

In accordance with EN ISO 12100, the washer has a main switch that also serves as an emergency stop, and an emergency stop button on the control desk. The compressed air supply is shut off with a manual valve, and the machine is marked with warning pictograms.

Benefits for the customer/user

• repeatable washing conditions and comparable results of technical cleanliness tests;
• recipes for different tank types, selectable from the panel;
• a closed circuit of heated liquid, meaning lower consumption of washing agent;
• convenient operation: foot switch, internal and external washing at one station;
• stainless steel construction resistant to washing liquids.