The Tornesh Dryer is a new innovation for drying wet solids. It can process foods, dairy products, pharmaceuticals, grains, solid chemicals, minerals and ores from 1 micron in size up to 1/2 diameter. Development of this product was initiated because of a need for a less costly alternative to fluid bed drying of fine powders or sluggish materials. Flash drying can sometimes be used but sacrifices in energy efficiency are typical and many materials cannot be completely dried in a flash dryer. Indirect dryers and tray dryers are very large, expensive, and unable to process sticky materials. The Tornesh Dryer provides a cost-effective and energy efficient means to processing these materials and many others. It also offers many other advantages over traditional drying equipment including less floor space requirements, ease of cleaning between product changes, and fewer components to maintain.
The name Tornesh Dryer was derived from the words "tornado" and "flash" because the dryer is a pneumatic dryer much like a flash dryer but the materials to be dried swirl in a cyclonic pattern like a tornado. The Tornesh Dryer is a direct-type dryer capable of handling a wide range of products. Wet product is introduced to the feed chamber via a screw conveyor or other feed device. The feed chamber consists of a bottom air plenum and side air plenum. The plenum surfaces are perforated with directional holes that create a circular hot air path. As wet feed falls to the bottom plenum, it begins to swirl and flow in a circular pattern. As moisture is removed from the product, it becomes lighter and eventually is entrained in the upward hot gas stream. If agglomerates are introduced to the feed chamber, they will dry and crack, exposing wet raw material to the hot gas stream. Eventually, all of the feed material is entrained in the upward hot gas stream.
The dried product then passes through an acceleration chamber and discharge chamber before entering a dust collector. The dust collector discharges the dried product. If further drying is required, an expansion chamber is added between the acceleration chamber and the discharge chamber. Partially dried product falls out of the upward gas stream in the expansion chamber and swirls along the outside surface until it becomes light enough to become entrained in the upward gas stream.
The walls of the acceleration chamber and expansion chamber can be jacketed for hot water, steam, or hot oil to add further capability. Cool water can also be circulated in the jacketed walls to prevent products from adhering to the inner surfaces as products near their melting point.
When extremely wet and sticky materials are processed, a feedback system can be used by bleeding off a portion of the dried material and mixing it with the wet feed material. Varying the ratio of the airflow supplied to the bottom plenum and the side plenum controls retention time. For longer retention times, the airflow to the side plenum is increased. For shorter retention times, the airflow to the bottom plenum is increased. The retention time is also increased by adding an expansion chamber. Three different expansion chambers are available and interchangeable.
The dryer is self-cleaning and there are no internal moving parts, so frequent access to the dryer interior is seldom necessary. If cleaning is required between product runs, a CIP system is available. The main body is a simple, tubular design that is very easy to clean. The individual chambers can be bolted or clamped together depending on your requirements. A uni-body design can also be supplied if necessary.
The Tornesh Dryer was developed to create an energy efficient and inexpensive means to dry wet powders and other difficult to handle materials. Besides the added benefits of minimal floor space requirements and ease of installation, it also offers complete system flexibility. The Tornesh Dryer can be used as a primary dryer or a pre-dryer in a multi-stage system. The process gas can be re-circulated to reduce emissions, save energy, or recover vapors.
A new Tornesh Dryer has been added to the lab facilities at Carrier Vibrating Equipment Inc.'s headquarters in Louisville, Kentucky to complement the conventional fluid bed, vibrating fluid bed, flash drying, slurry drying, and indirect drying test equipment already available. If testing at Carrier's facilities is not practical, the Tornesh Dryer can be shipped for field-testing. Either way, Carrier will provide a written process guarantee based on the testing. Carrier will test each potential Tornesh Dryer application as a stand-alone system or part of a multi-stage system, with the ultimate goal being the most cost-effective and efficient drying solution for the customer's needs.