A vertical in-vessel fermentation tank composts poultry manure in an enclosed, aerated and temperature-controlled vessel, typically in about 7–10 days, while collecting exhaust air for deodorization. The result is a stabilized organic fertilizer base with a fraction of the land use and odor of open windrows.
The challenge
Layer and broiler farms produce large, continuous volumes of manure. Stored or spread raw, it releases ammonia and odor, attracts flies, carries pathogens and weed seeds, and can contribute to nutrient runoff into surface water. Open windrow composting reduces these problems but needs large areas, regular turning, and good weather, and it still emits odor that can trigger complaints from neighbors.
Farms and fertilizer producers want a compact, enclosed process that sanitizes the manure reliably, controls odor and produces a consistent organic fertilizer base that can be sold or used on the farm.
Our solution
The reference solution is a vertical in-vessel aerobic fermentation tank. Blended manure is loaded at the top of an insulated, enclosed cylindrical vessel. A central hollow shaft with stirring arms rotates slowly, mixing the material while blowing air through nozzles on the arms, so oxygen is distributed across the whole bed. Aerobic microorganisms break down the organic matter and raise the temperature into the thermophilic range, which is what sanitizes the material.
Material moves downward through the vessel over the residence time and is discharged from the bottom by a hydraulic or mechanical outlet. Startup heating of the aeration air helps the process reach temperature quickly in cold climates. Exhaust gases are collected from the top of the tank and treated before release.
Because the process is enclosed and continuously aerated, it typically takes about a week to ten days in-vessel, compared with several weeks in windrows, and needs only a small footprint.
Process flow
- Receiving – fresh manure is delivered to a covered receiving area or hopper.
- Blending – manure is mixed with bulking amendment and, where useful, returned compost to adjust moisture, C/N ratio and porosity.
- Loading – a bucket elevator or conveyor lifts the mix into the top of the fermentation tank.
- Aerobic fermentation – the rotating shaft mixes and aerates the material; temperature and oxygen are monitored automatically.
- Discharge – stabilized material is withdrawn from the bottom of the tank on a timed schedule.
- Exhaust deodorization – collected air passes through a scrubber and/or biofilter to reduce ammonia and odor.
- Curing and finishing – discharged material is cured, then screened and optionally granulated or bagged.
Scope of supply
- Vertical in-vessel fermentation tank with insulated shell, hollow-shaft stirring system, hydraulic drive and discharge outlet
- Aeration blower with air heater for startup in cold weather
- Feed bucket elevator or conveyor and discharge conveyor
- Exhaust collection hood and fan with scrubber and/or biofilter deodorization unit
- Temperature and oxygen sensors, PLC control panel with remote monitoring option
- Process design for blending ratios, installation supervision, commissioning and training
Front-end mixers and downstream granulation or packing lines can be coordinated as part of a complete composting equipment package. For farms that also produce wastewater from washing, our wastewater treatment plants can be integrated on the same site.
Why this configuration works
Sanitization is controlled. Holding the whole bed in the thermophilic range, typically at 55 °C or more for several days, is the widely accepted basis for reducing pathogens and weed seeds. In a mixed, insulated vessel, temperature is more uniform than in an open pile.
Odor is contained. Fermentation happens inside a closed tank, and exhaust air is collected and treated rather than released across an open yard.
Footprint is small. A vertical vessel stacks the process upward, typically using far less land than windrows of equal capacity, which is valuable on established farms.
Operation is weather-independent. Insulation and heated startup air keep the process running in cold or wet seasons when windrows slow down.
Labor is low. Loading, mixing, aeration and discharge are automated, so the system runs with minimal daily attention.
Manure moisture, bedding content and amendment availability differ widely between farms, so blending ratios and tank size are set from the actual feedstock data.
To size a composting plant for your farm, send the bird count or daily manure quantity, moisture content, available amendments and intended fertilizer use to inquiry@waste-water-equipment-factory.com or via our contact page.
Reference configuration — final design depends on site data.
Design basis
| Feedstock | Poultry manure with bulking amendment (straw, sawdust or mushroom residue) |
|---|---|
| Design throughput | 5–30 t/day fresh manure (one or more tanks) |
| Mix moisture | Typically 55–65% after blending |
| Fermentation temperature | Typically 55–70 °C, held ≥ 55 °C for at least 3 days |
| Residence time | Typically 7–10 days in-vessel, followed by curing |
| Exhaust treatment | Collected air to scrubber and/or biofilter |
