1-1.4T/H Tropical Grass Hammer Mill in Colombia

Why a Dual-Purpose Farm in the Cauca Valley Needed a Tropical Grass Hammer Mill

The Cauca Valley is one of Colombia's most productive agricultural regions, with warm temperatures and abundant rainfall year-round. Elephant grass and Guinea grass grow rapidly – up to 80 tons of fresh matter per hectare per year. But the thick stems are a problem. Cows eat the leaves and softer parts, leaving the stems. The farm owner had been feeding long chopped grass from a stationary forage harvester, but the chop size was still 40-60mm – too long. The cows would sort through it.

He had seen hammer mills at sugarcane processing plants and wondered if a tropical grass hammer mill could work for his forages. He contacted us after a reference from a dairy in Costa Rica. He asked if our mills could handle the high moisture (sometimes 60-70% fresh) and the thick stems. We said yes, but the grass must be dried first – fresh grass at 70% moisture will clog any hammer mill. He started sun-drying the grass for 2-3 days before grinding, bringing moisture down to 15-18%.

The farm owner looked at a Brazilian-made hammer mill offered by a dealer in Cali. The price was $16,000 for a 55kW machine. He looked at a Colombian-assembled mill – $14,500 for a 45kW machine. He found us through a reference from a dairy in Costa Rica. Our price, delivered to the port of Buenaventura, was $11,200 for the SFSP66*60 with 55kW motor. This included the mill, the cyclone, the fabric filter bag, and a starter set of 4mm, 6mm, and 8mm screens.

Machine Selection and Drying Process

After testing dried elephant grass and Guinea grass samples, the farm owner selected the SFSP66*60 tropical grass hammer mill with a 55kW motor. This model has a 660mm rotor diameter and 600mm crushing chamber width – adequate for his throughput needs of about 1,500 tons of dried grass per year.

The drying process is critical. The farm built a simple solar drying shed with a clear plastic roof and concrete floor. Fresh-chopped grass (50-70mm pieces) is spread in a thin layer and dried for 2-3 days. In the Cauca Valley's warm climate, moisture drops from 70% to 15-18%.

The tropical grass crusher machine came with three screens. The owner tested all three on dried elephant grass (16% moisture):

• 8mm screen: Throughput of 1.4 tons per hour. Particle size: 75% between 2mm and 8mm, 15% below 2mm, 10% above 8mm. The cows ate most of it, but some thick stem pieces (over 10mm) remained. Waste: about 8%.
• 6mm screen: Throughput dropped to 1.2 tons per hour. Particle size: 85% between 1.5mm and 6mm, 10% below 1.5mm, 5% above 6mm. The cows ate everything. No visible waste. The owner chose the 6mm screen for both grasses.
• 4mm screen: Throughput dropped to 1.0 tons per hour. More dust. Not necessary for dairy cows.

For Guinea grass (which is leafier), throughput was slightly higher – 1.3 tons per hour on the 6mm screen.

The tropical grass hammer mill in Colombia discharges into a cyclone. The cyclone vent goes into a fabric filter bag. Dried tropical grass produces moderate dust – less than alfalfa but more than temperate grasses.

What the Ground Tropical Grass Is Used For

The farm produces a TMR for their dual-purpose cows:

• 50% ground tropical grass (6mm screen, mix of elephant and Guinea)
• 25% fresh chopped sugarcane (from the farm's own crop)
• 15% wet brewers' grains (purchased from a local brewery)
• 10% minerals and protein supplement

The owner reported that feed waste has dropped from 25% to under 5%. Milk production has increased by about 1.5 liters per cow per day – partly because the cows are eating the stems now, and partly because the TMR is more consistent.

What the Customer Said After 10 Months

We spoke with the farm owner about 10 months after delivery. Here is what he told us:

"The tropical grass hammer mill has transformed our feeding system. The 6mm screen is perfect. The cows eat everything now. No waste. The stems are ground fine enough that they cannot sort them out.

The drying process is the hardest part. We need 2-3 days of sun. During the wet season, we built a drying shed with a plastic roof. That works, but it's slower. We are planning to add a mechanical dryer next year.

The mill runs about 5 hours per day, 5 days per week. We have put about 1,000 hours on it. We changed the hammers at 500 hours – flipped them to the unused side. The 6mm screen is still the original – no holes.

Would I buy from RICHI again? Yes. The mill has paid for itself in reduced waste."

Logistics: Shipping from Qingdao to Buenaventura

Colombia's main seaport on the Pacific is Buenaventura. The mill was shipped from Qingdao to Buenaventura – about 35 days at sea. From Buenaventura, the customer arranged truck transport to the Cauca Valley, about 150 kilometers inland. Total transit time was about 42 days.

Pre-sale services that built their confidence

The farm owner was concerned about drying and moisture. Here is what we did:

• Material testing: He sent us 20kg of dried elephant grass and 20kg of dried Guinea grass by air freight. We ran them through an SFSP66*60 using 4mm, 6mm, and 8mm screens. The 6mm screen produced the best balance. We sent him the particle size analysis and a video.
• Drying advice: We explained that fresh grass at 70% moisture would not work. He built the solar drying shed based on our recommendations.
• Reference from a customer in Costa Rica: We put him in touch with a dairy in San Carlos that had bought an SFSP66*60 from us for tropical grasses. They confirmed that the 6mm screen worked well for their cows.
• Spanish manual: We provided the manual in Spanish.

A Note on Grinding Tropical Grasses

A few practical lessons from this installation:

• Drying is essential. Fresh tropical grass at 60-70% moisture will clog any screen. Sun-drying or mechanical drying to 15-18% moisture is required.
• Elephant grass has thicker stems than Guinea grass. Throughput is about 1.2 tons per hour on the 6mm screen – lower than Guinea grass.
• The 6mm screen works well for dual-purpose cows. The 8mm screen leaves waste. The 4mm screen reduces throughput.
• Dust is moderate. A cyclone with a fabric filter bag is sufficient.
• Hammer wear is moderate. Tropical grasses have more silica than temperate grasses. The owner got 500 hours from the first hammer set.

Global Reach of RICHI Hammer Mills

This project in Colombia is one example. RICHI has exported grass crushers for tropical grasses to over 80 countries. The SFSP66*60 is a popular choice for dual-purpose dairies in Central and South America because it can handle the coarser stems of elephant grass and Guinea grass. The 6mm screen is a standard recommendation for dairy cows.

A tropical grass hammer mill in Colombia makes economic sense for any farm with access to high-yielding forages like elephant grass and Guinea grass. The reduction in feed waste alone often covers the cost of the mill within two years.

If You Are Grinding Tropical Grasses for Dairy Cows

A few things to consider:

• Drying is essential. Plan for sun-drying or a mechanical dryer. Fresh grass over 18% moisture will clog fine screens.
• What screen size do your cows need? For lactating dairy cows, 6mm works well. For beef cattle, 8mm. For dry cows, 8mm.
• What is your grass species? Elephant grass (Napier) has thicker stems than Guinea grass. Adjust expectations accordingly.
• How will you handle the dust? A cyclone with a fabric filter bag is sufficient.
• What is your throughput requirement? The SFSP66*60 can handle 1.0-1.4 tons per hour on a 6mm screen, depending on the grass species and dryness.

If you grow tropical grasses for dairy or beef, a tropical grass hammer mill with a 6mm screen can reduce waste and improve feed efficiency. Send us a sample of your dried grass. We will test it with different screens and send you the particle size analysis. You can see the results before you decide. RICHI Machinery has exported hammer mills for forage processing to over 80 countries worldwide.