Turn and Screen

Turn and Screen

For many years Turn and Screen.com has focused on top quality equipment for the recycling and waste industries. Our expertise is in the following areas: compost windrow turners turner pusher design—no need for creeper-gear tractor, compost bagging system, compost covers, windrow management products - windrow watering system; windrow manager probe and productivity software, compost/topsoil screening equipment, small horizontal grinder, dairy bio-liquid/solid system that really works .

Company details

1818 Airport Road, Ste. 330 , Chapel Hill , NC 27514 North Caro USA

Locations Served

Business Type:
Industry Type:
Market Focus:
Internationally (various countries)

For many years, Turn and Screen.com has focused on top-quality equipment for the recycling and compost industries. Our expertise is in the following areas:

  • compost windrow turners
  • compost/topsoil screening equipment
  • small horizontal grinder
  • compost bagging system
  • windrow covers
  • windrow management products

Bacteria Farming
There is no magic, no shortcuts. There is only MANAGEMENT. Composting is simply a matter of making the indigenous bacteria very, very happy. If these bacteria are kept at their optimum environmental conditions (plenty to eat, good room-temperature, and lots and lots of fresh air) they will perform their natural work — making finished compost, in record time, without odors.

Windrow Dynamics
This is basically the natural, or unassisted, airflow and subsequent bacterial activity of an undisturbed windrow caused by heated air rising. The diagram above illustrates the concept of 'windrow dynamics'

Windrow Dynamics
In the illustration, Zone #1 represents what is referred to as 'the dead zone', or the anaerobic spot that normally begins immediately in a newly formed windrow. Zone #2, which is the most active zone, is the hottest and has the most biological activity. This zone is the ideal zone —the 'sweet spot' of composting. It is possible, however, to have temperatures rise too high in this zone, which will destroy beneficial bacteria. Zone #3 is the least compact zone in the entire windrow. It is cooler than Zone #2, but warmer than Zone #1. As the moisture evaporates and cool air penetrates, bacterial activity in this zone slows down rapidly.

Forming of the Zones
In most new windrows, other than straight yard debris, Zone #1 begins to form immediately and increases in size rapidly. What little oxygen exists is consumed rapidly, and the relatively high moisture content of the material begins to settle here. zone #2 is basically undefinable yet, but begins to form as a result of an active Zone #3, which remains small but active. If the row is not mixed and aerated soon , it will all become Zone #1. This is the most critical point because the odors generated can be cause of complaints that ultimately close the site. These zones must be refreshed promptly. All the material must change places and, preferably, must change zones. This is accomplished by completely mixing and aerating the windrow, which is exactly what the Frontier windrow turner is designed to do.

Particle Size
It is widely known that bacteria work only on the surface of the material. The more surface area that can be exposed, the more bacteria the material can support. As the structural integrity of the material weakens due to bacterial activity, the vortex action of the Turborator breaks up the material into smaller particles, increasing the surface area and dramatically accelerating microbial activity. Smaller particle size adds to the value of the end-product, and golf courses and turf growers, for example, will pay more for fine material (< quarter-inch.) However, particle size should be be considered in isolation, since there can be problems unless the challenge of aeration is also addressed.

Air Flow
Virtually every study on odors shows a direct correlation between lack of oxygen and the presence of odors. Forcing air into the material is important. Keeping it there is vital. Unlike other turners on the market that actually squeeze the material like a sausage-maker, it is the patented throwing action of the Turborator itself that forms and shapes the discharge pile, not the shape of the tunnel. The front-to-rear airflow is shaped into two distinct counter-rotating vortices — one is spiraling from the left, and the other, from the right. The 18 ft. wide turner generates in excess of 35,000 CFM of fresh air while turning 2,000 - 4,000 CFM of material. That's over 15 times more air being moved than material!
100% Mixing is Critical

The third action of the Turborator is mixing:

  • it assures that all the material is being exposed to every zone in the windrow
  • it distributes the various bacterial colonies to every part of the windrow
  • it re-establishes families of microbes destroyed by high temperatures in Zone #2, or due to lack of oxygen in Zone #1
  • it distributes the nutrients to every part of the windrow
  • it allows the windrow dynamics to begin with a Zone #2 condition
  • it equalizes the heat to every area of the windrow
  • it distributes the various types of material throughout the mix

The benefits of 100% mixing:

  • it results in a vast reduction in odors
  • it substantially increases the diversity of organisms working in the material
  • it results in a more complete biological breakdown of the material
  • the finished product is consistent
  • it insures the broadest variety of microorganisms in the finished product to encourage plant life

Aeration is not 'agitation', more the mere exposing of the material to the ambient air inside the tunnel, as rotootillers or flat paddle type turners do. The ambient air in the tunnel can be full of carbon dioxide released from inside the pile, and short on much-needed oxygen. The essence of successful turning/aeration is to force (and retain) fresh air into all the material, as well as to completely 'disrupt', 'reshape' and 're-stack' the row. This action thoroughly exchanges the material in all three Zones, creating an entire row with the characteristics of Zone #2. Over time, windrow dynamics will reform the three Zones. Therefore, proper timing of the turns will lead to a windrow with the optimal environment.

When a baker is making a cake from scratch, he does not simply place all the ingredients in a bowl, stir it and expect the cake to turn out OK. His primary purpose is to thoroughly mix all the ingredients; to eliminate chunks, ensure consistency and allows complete incorporation of the ingredients. The finished product—the cake— will be as good as the ingredients and how well they are blended. Now matter how you cut it, being able to produce consistent, mature compost with little or no odors does not happen by accident. It is the result of proper windrow management, with the unparalleled Frontier Windrow Turner with the patented Turborater.

Good screening is the cornerstone of successful materials handling. For producers in the compost-processing/recycling industry, we offer the following:

  • Small, vibratory screener
  • Grinder

For all your screening needs, we recommend only the best equipment on the market. We offer heavy-duty, portable, screening plant that cater to the small and medium-sized producer. In addition to the smaller lines of screening and shredding equipment, we offer screeners capable of screening high-moisture compost (organics) and topsoil, available in small medium and large capacity.