How to Choose the Right Screw Press Dewatering Machine for Manure Treatment
If you manage a livestock operation - dairy cows, pigs, poultry - you already know that manure handling is one of the most persistent operational and environmental challenges on the farm. The volume is continuous, the disposal options are limited, and the cost of doing nothing (odour, nutrient runoff, regulatory pressure) keeps rising.
A screw press dewatering machine is one of the most practical tools for solving this problem. But with different models, screen sizes, and throughput capacities available, choosing the wrong specification is easy if you don't know what to look for. This guide walks through the key selection factors.
Step 1: Calculate Your Daily Manure Volume
Before you look at any machine specifications, you need a reliable estimate of how much manure - as slurry or liquid - your operation produces per day, and how many hours per day you want the dewatering machine to run.
Rough production benchmarks (fresh, undiluted manure):
- Dairy cow: 50–80 litres per head per day (liquid manure at ~90–95% moisture)
- Pig (finishing): 5–8 litres per head per day
- Broiler chicken: 0.1–0.15 kg fresh weight per bird per day
Once you have a daily volume figure, divide by your intended daily operating hours (typically 8–16 hours) to get the required throughput in m3/h.
200-head dairy herd - 65 L/head/day = 13,000 L/day = 13 m3/day. If running 8 hours per day: 13 - 8 = 1.6 m3/h required. A CTYZ-200 (rated 3–6 m3/h) would comfortably handle this herd with headroom to spare.
Step 2: Understand the Feed Moisture Content
The moisture content of your feed slurry affects both the required screen aperture and the achievable output moisture. Most dairy and pig manure slurries contain 90–95% moisture. If your manure is diluted with washwater or mixed with urine from a slatted floor system, moisture content may be higher (95–98%), which reduces effective throughput and may require a larger model or pre-thickening step.
Higher dilution = more liquid to remove = more machine capacity needed.
Step 3: Select the Screen Aperture
The screen (also called the filter basket or wedge-wire screen) is the critical wear component in a screw press. Its aperture size directly determines:
- Separation efficiency - smaller aperture retains more fine solids in the cake
- Liquid clarity - smaller aperture produces cleaner effluent
- Throughput rate - smaller aperture can reduce flow rate
- Screen life - very fine apertures may blind (clog) faster with certain materials
For livestock manure, typical recommendations:
- Cow manure (flush system): 0.5–0.8 mm aperture
- Pig manure (liquid): 0.5 mm aperture with upstream fine solid removal recommended
- Chicken manure: 0.8–1.2 mm due to higher fiber content
Step 4: Match the Model to Your Throughput
With your required m3/h figure and material type confirmed, selecting the right CTYZ model is straightforward:
- CTYZ-160: Up to 3 m3/h - small farms, pilot systems, pre-treatment stage
- CTYZ-200: 3–6 m3/h - small to medium dairy or pig operations
- CTYZ-300: 5–10 m3/h - medium farms, 100–500 head dairy operations
- CTYZ-400: 8–15 m3/h - large farms, manure management systems
- CTYZ-500 / CTYZ-600: 12–25+ m3/h - large-scale operations, centralised manure processing
Don't size the machine to run at 100% capacity. A machine running at 70–80% of rated capacity will last longer, handle peak flow days without overload, and give you options if the herd grows. If between two models, choose the larger one.
Step 5: Check Your Electrical Supply
The screw press motor is specified for a particular voltage and frequency. In most countries this is straightforward (380V/50Hz in Europe, 460V/60Hz in North America), but it's worth confirming before ordering. Motors and control panels can be configured for any standard supply - just tell us your local spec when inquiring.
Step 6: Consider the Full System
A screw press is one component in a larger manure management system. For a well-designed installation, also consider:
- Feed pump: A chopper pump or progressive cavity pump is typically used to transfer slurry from the pit to the machine inlet
- Inlet piping: The machine inlet is designed for a specific pipe diameter - confirm before installation
- Solid conveyor: The dewatered cake at the discharge needs to go somewhere - a screw conveyor or belt conveyor to a storage bay is common
- Liquid collection: The press filtrate (liquid fraction) drains to a collection point - confirm your drainage plan before installation
We can provide a system layout drawing and equipment list for a complete installation if required.
Summary
Choosing the right screw press for manure treatment comes down to four numbers: daily manure volume, operating hours per day, feed moisture content, and required output moisture. Get those right and the model selection follows logically. If you're not sure about any of these, our engineering team can help you work through the numbers - contact us with your herd size and we'll provide a specific recommendation within 24 hours.