The double screws compost turning machine is a piece of turning equipment specifically designed for aerobic fermentation troughs; it is suitable for turning and aerating organic wastes such as livestock and poultry manure, sludge, sugar mill filter mud, straw, and sawdust during the fermentation process. The equipment straddles the rails on both sides of the fermentation trough and travels longitudinally along it, utilizing two parallel spiral shafts that rotate synchronously in opposite directions to deeply turn, break up, and mix the materials within the trough.

Working Principle of the Double Screw Compost Turning Machine

The core components of the equipment are two symmetrically arranged spiral shafts featuring wear-resistant alloy spiral blades welded in a staggered pattern. During operation, the left spiral throws material to the right while the right spiral throws it to the left; the blade angle continuously excavates and lifts material from the bottom of the channel, scattering it in a crisscross pattern through the air.

The value of this design lies in its ability to go beyond merely turning the surface layer; it effectively swaps the positions of the bottom-layer anaerobic material and the top-layer material, achieving true three-dimensional turnover across the entire width and depth of the channel. This ensures thorough contact between the material and the air, providing ample oxygen for aerobic microorganisms.

What are the application scenarios for the double screws compost turning machine?

The double screws compost turning machine covers three main areas:

Organic fertilizer production

Used in conjunction with fermentation troughs and screening equipment to enable large-scale, standardized production. The turner serves as the primary site for the biochemical reaction process.

Livestock and poultry manure treatment

Facilitates the centralized fermentation of manure into organic fertilizer, enabling resource recovery and utilization.

Environmental solid waste disposal

Processes organic solid waste such as municipal sludge and kitchen waste. When used with enclosed fermentation sheds and negative-pressure odor extraction systems, it ensures high capture rates for dust and odors generated during turning, making it easier to pass environmental impact assessments.

Other suitable applications

Also suitable for turning and aerating compost substrates at horticultural nurseries and button mushroom cultivation facilities.

What are the core advantages of the double screws compost turning machine?

Uniform turning with no dead zones

The twin spirals operate in a counter-rotating, synergistic manner, casting material across a distance of 1.5-2.2 meters and achieving fermentation uniformity of over 92%. Issues common to traditional single-spiral turners—such as dead zones at the edges and corners or a "dead layer" of unmixed material at the bottom——are virtually eliminated by the twin-spiral design.

Deep turning and powerful pulverization; versatile material handling

It handles a wide range of organic wastes——including livestock manure, crop stalks, sludge, and sugar mill filter mud—and accommodates moisture content levels between 30% and 80% without complex pre-treatment. It can fully turn material in a single pass within deep troughs (1.5-2.0 meters deep and 3-6 meters wide), making it ideal for processing mixtures such as livestock manure with stalks or municipal sludge blended with bulking agents. The spiral blades feature a self-cutting action against fiber entanglement and minor clumping, resulting in fewer jams compared to standard straight-tooth cutter shafts.

Rugged durability and low failure rate

The machine body is constructed from thickened carbon steel treated for rust, corrosion, and wear resistance. The spiral blades are made of high-manganese steel or high-chromium cast iron, with options for a tungsten carbide wear-resistant coating. Equipped with limit switches, the system maintains a failure rate of less than 0.5%.

What are the common issues associated with double screws compost turning machines?

Q: What is the actual difference between twin-screw and single-screw models?

A: The main issue with single-screw turners is uneven turning, which tends to create a "dead layer" of unmixed material at the bottom of the trough. Twin-screw models utilize two counter-rotating shafts working in tandem to gather material from the sides toward the center and lift it from the bottom, achieving full-profile turnover. Simply put, a single-screw turner “ sweeps the surface” whereas a twin-screw turner“turns the material all the way to the bottom”.

Q: Is the equipment installation complex?

A: The equipment features a compact design and is easy to install. The key is ensuring shaft parallelism and proper gear backlash during installation. Manufacturers typically provide on-site installation guidance.

Q: Can it handle high-moisture materials?

A: Yes. The equipment is suitable for materials with a moisture content of 30%-80%. For high-moisture or clumped materials, the hydraulic drive system delivers stable power, allowing for easy breakdown without the need for pre-processing.

Q: Can a single machine only service one trough?

A: No. The equipment can be paired with a transfer carriage to enable automatic movement between multiple troughs. A single machine can service several fermentation troughs in rotation, significantly reducing equipment investment costs.