The award-winning Earth Flow™ is an automated in-vessel composting system designed to limit labor. Since mixing, aeration and moisture addition is automated, this system requires little beyond loading and unloading. The Earth Flow provides excellent control over moisture, odors, vectors, and leachate.

The Earth Flow is capable of composting between 300 pounds and 3 tons per day of biodegradable material (depending upon system size and retention time of material). The auger mixes, breaks up, and aerates the compost producing a rich, friable (e.g., light and fluffy) mix.In-Vessel Earth Flow

The Earth Flow In-Vessel Composting System can be operated as either a batch or a continuous flow composting system:

  • Batch Process: the system is fully loaded with feedstocks. These materials are composted as a batch and then fully discharged. This approach works well for materials such as biosolids, where it is necessary  to isolate material for pathogen reduction.
  • Continuous Flow Process: feedstocks are added into the load end of the vessel and compost is discharged from the other end. In this process, the auger moves the compost slowly toward the discharge end of the vessel. Once materials arrive at the discharge end, the compost is ready to be removed from the system.




1. Feedstock Loading

An organic “recipe” (for example, a mixture of food waste and wood chips) is loaded into the Earth Flow through the load doors via a                      variety of means including manual emptying of containers, using a front-end loader, using tote tipper or chute.

Plastic contamination should be limited. Hard foods such as pineapples, hard crusted loaves of bread, etc. should be chopped up prior to       addition. Since food scraps are wet, a dry bulking agent such as wood shavings must be added to create a balanced compost recipe.

Prohibited materials in an Earth Flow include: long-fiber materials such as tall weeds, rope, clothing, tree branches, bioplastic bags(these get wrapped around the auger) as well as large rocks and sand.

2. Mixing and Active Composting

Once the new material has been added, the traveling auger system blends the new feedstock with existing compost mass. A complete mix can take 30 minutes or more. The auger is programmed to mix automatically one to four times per day.

Thermophilic composting at temperatures above 115° F occurs rapidly in the insulated bin. The food wast “slow cooks” at this temperature and is easily shredded by the auger. Continue adding feedstocks until the bin is filled to the top of the auger screw.

3. Unloading and Curing the Compost

Once the active composting cycle is complete (approximately 14-21 days), composted material can be removed through the discharge end of the vessel. There should be no residual food waste and the material should have a pleasant odor and a black or dark brown color.

The composted material can be discharged automatically using the auger into a bin, rolling cart, truck or conveyor. Alternatively, a front end loader can enter the system to remove compost directly.

This compost can be used immediately as a cover mulch or can be cured in a pile for 30-60 days before being used as a soil amendment. Screening will eliminate residuals (for example, bones and large wood chips) and plastic contaminants, making the finished product even finer.

The Earth Flow In-Vessel Composting System can process 300 pounds to 3 tons of material per day.

  • Schools and Universities
  • Corporate Campuses
  • Remote Communities
  • Parks and Resorts
  • Agricultural Facilities
  • Military Bases
  • Correctional Facilities


The Earth Flow In-Vessel Composting System has an integrated mixing system that allows the compost to be mixed on a daily basis (2-4 times per day). Traveling auger technology provides optimum conditions for hot food waste composting with seven distinct operating functions:

  • Shred – The auger tears up food waste clumps as they cook to reduce particle size and increase available surface area, making the particles more available to the microbes.
  • Mix – The auger mixes material by folding food waste into bulking agent.
  • Aerate – The auger continually fluffs the compost to add oxygen to the matrix.
  • Distribute Moisture – The auger sweeps up wet material from the base of the pile and elevates it to the surface. This maintains an even distribution of moisture throughout the pile.
  • Homogenize – The auger homogenizes food waste with bulking agent for an even distribution of nutrients.
  • Transport – The auger slowly increments compost from the load end to the discharge end.
  • Stack – As compost reduces in volume, the auger continually stacks the material toward the back to maximize utilization of the space.


  • Limits Pests and Nuisance Odors The Earth Flow system incorporates five different engineering controls to prevent pests and nuisance odors.
  • Superior Compost Quality The inclined/vertical auger combines with the positive aeration system to produce an extremely rich, light, homogeneous, oxygenated compost.
  • Cost Effectiveness For its size and capability, the Earth Flow is the most cost effective in-vessel composting system on the market today.
  • Small Footprint  When space is restricted, the Earth Flow is ideal because it maximizes the amount of composting that can be done on its very modest footprint.
  • Complete Control  The Earth Flow gives you complete control of your composting process, allowing you to control temperature, moisture content by adjusting patterns for mixing, aeration and moisture addition.
  • Speed of Composting The Earth Flow system is capable of thermophilically composting food waste in 14-21 days (an additional 1-2 months curing time is recommended after compost exits the Earth Flow).
  • Year Round Composting Capability  Designed and field tested for extreme weather conditions (such as snow, wind and extreme cold).

Earth Flow Specifications

Vessel Specifications EF-20 EF-24
System Capacity (cubic yards) 23 27
Processing Capacity (lbs / day) 1330 1600
Processing Capacity (tons / day) ~0.67 ~0.80
Length – Overall 20′ 24′
Width – Overall 8′-4″ 8′-4″
Approx System Weight (lbs) 7,000 8,000

Earth Flow – Heavy Duty

Vessel Specifications EF-30 EF-40 EF-5010
System Capacity (cubic yards) 34 45 74
Processing Capacity (lbs / day) 2000 3000 6000
Processing Capacity (tons / day) ~1.0 ~1.5 ~3
Length – Overall 30′ 40′ 50′
Width – Overall 8′-4″ 8′-4″ 10′
Approx System Weight (lbs) 10,000 13,000 18,000

Mixing Auger Specifications

Mixing Auger 14″ 304 Stainless Steel (13″ on EF-12)
Gear Motor 5hp 3ph (3hp on EF-12, 208/230/460V – 50/60Hz)
Gear Box Helical bevel synthetic lube
Carriage Drive VS 1/4 hp motor (1/2 hp for EF-30 and up)
Rail Drive VS 1/4 hp motor (1/2 hp for EF-30 and up)
Control Panel Programmable PLC in NEMA 4X panel
Power Requirements (Motors) 30A 220V single or 208V 3 phase
Vessel Insulation R-18 (optional)
Temperature Probe 30″ Hand Held

Blog Posts About the In-Vessel Earth Flow Composting System

In-Vessel Earth Flow FAQ
In-Vessel Earth Flow FAQ
In-Vessel Earth Flow Features And Benefits
In-Vessel Earth Flow Features And Benefits
Earth Flow Business Case White Letter
Earth Flow Business Case White Letter
Earth Flow 2014 Building Green Award
Earth Flow 2014 Building Green Award
AASHE Composting Inside of a Greenhouse
AASHE Composting Inside of a Greenhouse