Products Description
The trommel screen is mainly used to classify materials or remove impurities according to particle size in composting. Its applicability depends on the physical properties of the compost and the processing objectives. The following is an analysis of the compost types and screening scenarios applicable to the trommel screen:
Composting types suitable for trommel screens
1. Urban domestic waste composting
Features: After fermentation, domestic waste compost often contains impurities such as plastic, glass fragments, and stones, and the particle sizes are uneven.
Sieving effect: The drum screen can screen out fine particles ≤5mm (for soil improvement) and coarse particles >5mm (need secondary sorting or removal of impurities).
Applicable conditions: The moisture content of compost must be controlled below 30% to avoid adhesion and clogging of the sieve holes.
2. Agricultural waste composting (such as straw, livestock and poultry manure)
Features: high fiber content, loose particles, and low humidity.
Sieving effect: After screening, fine particles (≤10mm) can be directly used as organic fertilizer, and coarse particles (such as uncomposted straw) can be returned to the fermentation tank for further processing.
Advantages: The rotating motion of the drum screen can break up the agglomerated materials and improve the screening uniformity.
3. Garden waste composting (twigs, leaves)
Features: There are many wood fragments, and large pieces of undecomposed materials need to be screened to remove them.
Screening function: The screen holes are usually set to 8-20mm, retaining the decomposed fine materials and separating the undecomposed wood chips for secondary crushing or composting.
4. Industrial organic solid waste composting (food processing waste, wine lees, etc.)
Features: Containing grease or high-humidity and sticky substances (such as kitchen waste composting).
Applicability: Pretreatment is required to reduce the moisture content (such as adding sawdust to adjust), or choose a drum screen with a clearing device (such as a bouncing ball, a brush) to prevent the screen holes from sticking.
Advantages and limitations of drum screen screening**
Advantages
Efficient grading: Multiple layers of screens can be configured (such as 3-5 layers) to separate multiple particle sizes at one time (for example: coarse residue>15mm, medium material 5-15mm, fine material<5mm).
Strong adaptability: By adjusting the rotation speed (usually 3-20r/min) and inclination angle (3°-5°), it can match composts with different humidity and viscosity.
Low maintenance cost: The screen material can be selected from wear-resistant materials such as manganese steel and polyurethane, with long service life and easy replacement.
Limitations
High-humidity and sticky compost: When the moisture content is greater than 40%, the screen holes are easily blocked, and drying or adding auxiliary materials (such as rice husks) is required to reduce the viscosity.
Fiber compost: Long-fiber materials (such as unbroken straw) may wrap around the drum shaft and need to be pre-crushed.
Optimization suggestions
1. Pretreatment: Turn the high-humidity compost over and dry it first or add moisture-absorbing auxiliary materials (such as bentonite).
2. Equipment selection: Choose a drum screen with self-cleaning function (such as a built-in high-pressure air nozzle), or use a vibrating screen to improve screening accuracy.
3. Maintenance and management: Regularly check the wear of the screen and clean up the blockage in time to avoid a decrease in screening efficiency.
By rationally configuring the parameters of the trommel screen and combining the characteristics of composting, the commercial value of compost can be significantly improved to meet the grading needs of agriculture, gardening, industry and other fields.
