Serious factory level food production requires the use of tumbling drums for size reduction, crumbling, crushing and mixing. Machine manufacturers can make tumbling drums that have multiple speeds and voltages. The most popular barrel dimensions of the tumbling drums vary in diameter (18″ to 36″) and in length (18″ to 42″). Usually, the diameter is smaller than the length. Horizontal barrel speeds vary from 20 to 38 RPM, depending on the barrel size and the items to be tumbled.
Screening falls under two general categories: dry screening and wet screening. From these categories, screening separates a flow of material into grades. These grades are then either further processed to an intermediary product or a finished product.
For dry tumbling, the horizontal octagonal barrel is used almost exclusively. This barrel sometimes has a metal skin, and a hardwood lining which can be replaced when necessary. A barrel that is 30″ in diameter by either 36″ or 42″ in length is considered standard. Tumbling will take anywhere from 6 to 24 hours Tumbling will take anywhere from six to 24 hours depending upon the amount of material to be removed from the parts. A two-compartment barrel mill is designed for dry milling of construction materials of low and medium hardness.
Rotary crushers are typically built with shaft impactors to create considerable force. The are ideal for both recycling and food processing and can be calibrated for a size reduction ratio between 10:1 and 25:1.
Rotary speed varies from 85 rpm to 1,200 rpm. Modern models can be customized with different sets of hammers that enable the machine to work on different materials.
For barrel loads, the optimum load height is 50%, with approximately three parts media to one of parts to keep parts from impinging. Barrel load heights should not be less than 45% or more than 60% of capacity including parts and media. Load heights between 40% and 45% produce more action but a poorer finish. The number of parts which will fit safely into a barrel will be determined by the barrel size, size of the part, the fragility of the part, shape and weight and the end result desired. Parts usually account for 1/3 of the total barrel load.
High frequency vibrating equipment is a shaker whose frame is fixed and the drive vibrates only the screen cloth. High frequency vibration equipment is for particles that are in this particle size range of an 1/8 inch or three mm. down to a +150 mesh.
A Rigimill provides solutions for marine, aerospace and automotive Industries. It uses a rigid hammer that is a great mill for use in a wide range of applications from pre breaking to fine grinding, depending on product characteristics It has been established that a full circle hammer mill will be able to grind at a 15% higher capacity than a half circle hammer mill because of the larger screen area. This is true for hammer mills using the same screen hole size and using the same horsepower.
For your tumbling drum needs, look for the reputable manufacturer that has the resources and ingenuity to design parts feeders to suit all of your industrial automation requirements.
