PES Promeco Extruder System ©

The PES - Promeco Extruder System ® - is the simpler, more flexible, efficient and effective solution to the problems of agglomeration and volume reduce compacting to produce briquettes & pellets.

The flexibility of this machine allows you to treat different materials. PES systems have been successfully used to process:

• Mixed plastics, paper and cardboard, textiles and wood
• Commercial waste and waste residual from sorting plant
• Industrial solid waste similar to municipal waste
• Plastics (PE, HDPE, EPS, PP, PVC, Mix of polymers etc..)
• Mix composed by  the constituents of the typical inorganic fraction of MSW used as RDF (lightweight plastics, textiles, wood, paper and cardboard);
• car fluff after pre-treatment plant
• Wood waste and green waste

The applications of PES system are endless. Amongst them:

• Production of RDF pellets (thickened or briquettes)
• Production of profiles and/or finished goods (e.g.: spacers for pallets; poles for agriculture, wheel stoppers for cars; profiles for walls, structures and insulation; curbs outdoor)
• Agglomeration of mixed plastics
• Pre-treatment of the organic fraction for composting
• Production of peat substitute for wood waste

PES systems have been successfully used upstream of traditional extruders, exploiting  their characteristics to pre-treat the material. More specifically, PES are particularly suitable for the pre-treatment of materials in output from washing lines (packaging films, agricultural films).

Principles of Operation

The PES is a twin-screw extruder with short screws, that agglomerates the material in input combining the effects of pressure and mechanical friction, determining a significant increase the temperature of the material in the extrusion chamber.

The input materials are loaded in the feeding bunker  (Pos 1) of the PROMECO EXTRUDER SYSTEM.
Material to process is received in a  receiving bunker equipped with two screws, and  is fed to a vibrating  table (Pos 2) dosing and regulating the flow entering in the extrusion chamber (Pos 3), where a process of "thermo-mechanical disintegration" takes place, thanks to the heating of the material and its partial disruption induced by mechanical friction. The temperature increase allows for the dehumidification of treated material, the removal of organic impurities, and the melting of materials which can act as "glue" for others (eg, low melting point plastics such as polyolefins).
The motor is generously oversized, to guarantee the best results even when dealing with "difficult" materials. However, in most situations the total power available is used only to the extent of 60%.

Based on readings of a level probe, the feeding/dosing operations can be stopped and to be restarted according to the need of material.
Agglomerated/densified material comes out of the extrusion chamber through a matrix  (Pos 5), whose section is a function of the required characteristics (size and shape). Matrix is equipped with a system controlling the pressure on the processed material; in case of pellets production this system is not necessary.
Extruded material comes out from the matrix in a continuous way, and a cutting system guarantees the adjustment of the length of the final product. Above the extrusion chamber and the cutting system is an aspiration system to collect any dust and vapours and send them to treatment.
The PROMECO EXTRUDER SYSTEM is designed to operate under heavy loads, and this determined the considerable strength and sturdiness of all the machine components, starting from its structure. Forces are balanced, and only the static weight of the machine is discharged to the machine structure, which must be positioned on a proper floor.
The cooling system of the gearbox, tightly bound to the Extruder, consists of an oil closed circuit.
The speed of main motor (Pos 4) is adjustable, allowing the optimization of the screws rpm  according to the quantity of material actually treated and the desired characteristics of the output.

Flexibility of the system

Waste is characterized by the inconsistence of its quality. Moisture, density, composition and size can vary significantly.
The PES system was designed to automatically compensate for any fluctuations, in order to maintain as stable as possible the production rate or quality of the output.

The main motor is generously oversized in order to maintain the production rate even in the presence of material more "difficult" to treat. Under normal conditions, however, is used 60% of installed capacity.

The control system, based on PLC, continuously monitors several parameters, including electrical power consumption and temperature of the extruded material, in order to adjust the operations of the machine accordingly.
The control action is based on this principles:

• Decrease in electrical power consumption: the speed of the augers of the feeding bunker is increased, in order to maintain a constant production rate
• Increase in electrical power consumption: the control system acts on the matrix of extrusion, by opening the top, allowing an easier flow of material.
• Decrease in the temperature of the material, below a desired value: the control system closes the matrix extrusion, decreases the speed of the augers of the feeding bunker, reduces the motor speed.
• Increase in the temperature of the material: the control system opens the extrusion matrix, increases the speed of the augers of the feeding bunker and increases the speed of main motor

Input materials

1. MSW overscreens, paper, cardboard and plastic

• Absence of metal fractions and of inerts with a diameter > 4 mm
• Optimal size of about 40x40x10 mm
• Average humidity 15%, max humidity up to 20-23% depending on the characteristics required for the briquettes.
• Relatively homogeneous mixture of materials, with a minimum of 25% (in weight) of low melting plastics (polyethylene, LDPE film).

2. Thermoplastic and thermosetting plastic waste

• No metal fractions or aggregates with a size diameter > 4 mm.
• Low amount of foreign material.
• Particle size previously reduced by grinding.
• Mixed plastics having similar melting point (low melting / high flux)
• Polyethylene (washed or unwashed), even if mixed with other materials; polypropylene; PVC; ABS; Polycarbonate

3. Car fluff from auto shredder residues (ASR)

Material to process consists mainly of a mix of plastics, elastomers, rubber parts, textiles, protective coatings, electrical cables, glass, soil fractions and non-ferrous materials in general.
The requirements that such a mix must satisfy in order to ensure the effectiveness of the extrusion process are essentially:

• Minimal presence of metals, and absence of inerts with a diameter > 4 mm.
• Optimum particle size of about 40x40x10 mm, easily achieved with a pre-grinding.
• Max humidity up to 20-23% depending on the characteristics required for the briquettes / pellets.

4. Organic waste

• No metal fractions or aggregates with a diameter > 4 mm.
• Reduced presence of foreign material (plastic < 5%).
• Particle size previously reduced by grinding, shredding or chipping.
• Homogeneity of the input waste, with a fibrous cellulosic material content of at least 25-30%.

The degree of wear of the parts depends essentially on the waste composition and on the presence of inert and metal fractions; metals increase significantly the wear of mechanical parts and therefore must be removed first. The wear parts are replaced every 250 ~ 1,000 hours but can be restored by the addition of materials with hard solder.
The estimated cost relating to the wearing parts can be estimated at about 2.00 ~ € 3.00 / ton.

Products

Densified RDF, RDF pellets and  briquettes:

• Densified RDF is obtained pressing and slightly melting the fluff; the result is a material pressed at low compaction and adhesion. The main function is to increase the specific gravity of the material while maintaining a high degree of flammability of the product.
• Pellets have a diameter of 30-40 mm and medium-high adhesion and compaction. The product has a low flash point.
• The briquette has different shapes, sizes from 40-200 mm, an average degree of compactness and high adherence. Briquettes can then be ground (in a shredder without grate) to obtain a mix of high density material with a variable size 5-80 mm, particularly suitable for fluidized bed furnaces.
• Specific gravity  between 0.4 and 1.2 kg / dm³.
• Moisture content ranging between 2 and 11% depending on the composition of the refusal to start.

Densified plastics for granulation and finished products

• Output material diameter output between 30 and 60 mm.
• Input material humidity <18% H₂O
• Moisture content between 2 and 10%, usually depending on the composition

PROMECO Extruder advantages:

• Strong reduction of the time to densify the product
• Fewer machines to install and manage, and relative reduction of investment costs
• Small areas occupied
• Minor electric power installed and used
• Simplified maintenance
• Increased productivity and versatility
• Reduced cost of investment and operations

Compost:

The products obtained with the PROMECO EXTRUDER SYSTEM is not a mature compost, but a matrix having the characteristics of a high-compostable waste, due to:

• Increase in porosity with consequent better possibility of ventilation
• Significant increase in specific surface area available for aerobic bacteria.
• Optimization of the structure, size and texture of the matrix.
• Reduction of moisture content.
• Specific weight of the treated waste of about 250-350 kg / m³.

Benefits of treatment with PROMECO Extruder:

• Strong reduction in the time required to compost the product
• Reduction of the areas to be allocated to composting operations, with reduced investment costs
• Elimination of leach ate.
• Removal of unwanted odors
• Peat substitute:
• Pulping wood fiber material, highly porous, with a density of approx. from 50 to 200 kg / m³ according input material quality.
• Intrinsic technical characteristics similar to peat.
• Similarities with respect to the use of peat in agriculture and floriculture

Production capacity

Briquettes:

Capacity changes depending on the characteristics of the treated waste and the desired output; it can reach 4,000 kg/h.
When processing a properly mix of paper, cardboard, textile, wood and plastic having specific weight of 200-250 kg / m³, humidity below 15%, average size of 40 mm, to get an output having 150 mm diameter, density 1,1 kg / dm ³, the expected treatment capacity of a machine PROMECO EXTRUDER SYSTEM 600 is up to 2,500 kg / h.

Pellets:

The capacity of a  PROMECO EXTRUDER SYSTEM type 600 producing pellets with a diameter 30 mm is up to 2,500 kg / h. Input material must be free of metals, cables, high-melting plastics scraps with long size, as they could overlap or obstruct the exit.
When processing a mix consisting of paper and plastic (50% -50%),having specific weight of 200-250 kg / m³, humidity below 15%, size of about 30 mm, in order to get pellets with 35 mm diameter, density 0, 7 kg / dm³, the treatment capacity of a machine type PROMECO EXTRUDER SYSTEM 600 is about 2.000 kg / h

Plastics (LDPE, HDPE, PP, ABS, PVC, polyvinyl chloride, etc..)

The treatment capacity strongly depends on the characteristics of the mixture of plastic in input and required characteristics of the final product. When processing plastic scraps with a density of about 180-220 kg / m³, humidity below 15%, about 4 cm in size in order to get a continuously agglomerate product output Ø = 40 mm, the treatment capacity of a machine type 600 is PROMECO EXTRUDER SYSTEM approximately 1,500-1.800 kg / h.

Compost:

Capacity strongly depends on the composition of the mixture, and on the structure and particle size for the desired output product. It ranges, in case of PES600, between 20 and 30 m³ / h

Substitute for peat:

The production capacity depends on the type of the ligno-cellulosic waste to be treated, and on the structure and size desired for the output products. It ranges, in case of PES600, between 8 and 30 m³ / h.