The can enters the filling machine through the can feeding star wheel , reaches the predetermined center after the can table, and then the filling valve descends along the supporting cam to center the can and pre-press to seal. The cylinder is pressurized, and the air pressure in the cylinder can be adjusted by the pressure reducing valve on the air control cabinet. The back pressure gas in the cylinder is flushed into the tank and flows into the vacuum channel. Vacuuming is used to implement the CO2 flushing process to remove the air in the tank. Through this process, the oxygen increase of the material is reduced to the lowest level during the filling process, and no negative pressure is generated in the tank. Therefore, even if the wall is very Thin aluminum cans can also be flushed with CO2.
For filling without vacuuming, the filling machine can directly use the CO2 gas in the original vacuum channel to directly flush the tank. After the vacuum valve is closed, the equal pressure is established between the tank and the cylinder, the liquid valve is opened by the spring, and the filling begins. Install the cylinder.
Change the height of the filling level by changing the length of the return air pipe.
When the liquid level of the material reaches the return gas pipe, the return gas is blocked, the filling is stopped, and an overpressure is generated in the upper gas part of the tank, thereby preventing the material from continuing to flow down.
The fork closes the air valve and the liquid valve. Through the exhaust valve, the exhaust gas balances the pressure in the tank with the atmospheric pressure, and the exhaust channel is far away from the liquid surface, thereby preventing the liquid from being brought out during exhaust.
During the exhaust period, the gas at the top of the tank expands, the material in the return pipe falls back into the tank, and the return pipe is emptied.
At the moment when the can is out, the centering cover is lifted under the action of the cam, and under the action of the inner and outer guards, the can leaves the can table, enters the can conveying chain of the capping machine, and is sent to the capping machine.
If the liquid level in the tank is unstable, insufficient filling or foaming will occur during filling. Therefore, it is very important to control the liquid level in the tank stably for normal filling.
The whole liquid level control device is composed of reed switch type float liquid level sensor, digital regulator, eccentric rotary valve (including valve positioner) and so on.
The liquid level in the cylinder is measured by the reed switch type float liquid level sensor, and converted into a current signal of 4-20 mA, which is passed through the mercury rotary joint. It is sent to the digital regulator. After PID adjustment, the output signal is sent to the electrical valve positioner of the main liquid inlet valve to control the opening of the main liquid inlet valve and achieve the purpose of controlling the liquid level of the filling tank.
The liquid level in the filling tank can be set at any time on the digital regulator as required, and the entire liquid level control device will adjust the liquid level in the tank in real time according to the change of the set value.