Stabilized compost according to Pal

6 May 2013

Pal Green Division, the PAL-IMAL group’s division dedicated to the environmental sector, broadens its production range by developing two important solutions dedicated to the treatment and recovery of organic fractions of waste.

As regards refining techniques, a system was developed, as an alternative to traditional methodologies, with rotating sieves, star and disc screens, plastic remover.

In this case the set objectives were:

- general specific increase in the compost production;

- possibility of obtaining very high quality fractions for agronomic and nursery-gardening uses;

- sharp reduction in dust emissions during plant processing;

- reduction in the overall amount of waste to be sent to the landfill;

- possibility of recovering and recycling bulking agents of vegetable matrix;

The proposed plant comprises:

- a main sieve, the STEPPER SCREEN

- a secondary refining sieve (DYNASCREEN or VME);

- a plant for light pollutants suction and dust collection.

Thanks to the new screening concept patented by PAL, the STEPPER SCREEN combines within a single machine the possibility of separating fine organic matrix (<30 mm) from the polluting and/or bulking agents with a specific yield that is considerably higher than that of rotating screens. At the same time, through the extraction system integrated in the machine it is possible to remove light pollutants (plastic, textiles, paper, etc.) from the bulking agents of vegetal origin.

Therefore, the machine generates three fractions made up of:

- fine organic matrix (<30mm) to be refined;

- clean vegetal bulking agents to be re-circulated for subsequent cycles;

- light pollutants to add to the final disposal or the production of RDF.

The fine organic matrix is subsequently refined by two final screens, to be identified in relation to the overall rate of moisture of the stabilized compost.

For organic matrix with moisture greater than 30% a precision roller screen is used, the DYNASCREEN. The machine is fitted with a bed of precision rolls, the rolls being responsible for gauging the product depending on the desired size. The machine is extremely dynamic and through simple operations it allows to change the size of the final product also in several separate fractions.

As regards matrices with lower moisture rate (<30%) we recommend the use of the VME, an oscillating multi-stage screen that generates selected and higher quality final product.

All machines are enclosed and connected to the suction plant as part of the system. The system thus is extremely clean and free from dust emissions during the production processes and, all dust collected is fully recovered in the fine compost thereby increasing the specific yield of the compost produced by the plant.