Early domestic vacuum material suction machine technology improvement case;

The vacuum feeding machine (suction hopper) is a widely used auxiliary equipment in the plastic molding industry. Its function to use low vacuum to suck raw materials into the drying hopper of molding machines such as injection molding machines and extruders.

Imported suction hoppers take into account many possibilities in actual production, such as material shortage, full barrel, fan failure, etc., and are equipped with shutdown alarm devices to avoid the invalid operation of fan and also bring convenience to on-site maintenance and operators to solve such problems.

However, domestic suction hoppers did not have the functions of shutdown alarm for material and full barrel at that time. In this way, when the material in the oven is full, the level switch often still closes, or there is no material in the suctionper, and the fan is still intermittently circulating. Frequent startup not only wastes a lot of electricity but also causes excessive wear of the equipment.

We can solve above problems by improving and simplifying the electrical control circuit of the suction hopper.

Improved working principle: The discharge valve is automatically closed, sQ is closed KM is sucked up, the fan is started, and the material is started to be fed. When the 405 timer is up, KM (fan contactor is disconnected, the fan stops, and the discharge timing starts (about 205). Due to the disappearance of vacuum, the valve is opened under the action of gravity the raw material, the material is discharged, and the valve is closed after the material is emptied, and the next cycle starts.

In this circuit, if you add time relay KT2 (dashed line), you can achieve the effect of automatic shutdown when the barrel is full and the material is discharged. The time relay KT2 is to twice the time of material addition plus material discharge time. Since the level switch sQ is always in the closed position when the barrel is full or the material is short, if discharge valve does not open to discharge the material in the next working cycle, it can be considered that the addition hopper is empty or the oven is full, and the KT delay contact is disconnected, the fan stops, and when the raw material is consumed to a certain extent, the valve is opened to discharge the material, and the next cycle is automatically.

After the suction hopper is improved, the benefits are very obvious, more energy-saving, and the frequent startup of the suction hopper motor is avoided extending the service life of the suction hopper.