Chain Mills are machines designed to reduce the particle size of a material by impacting the material with the high velocity rotation of a series of links of chains. In a dual rotor chain mill, there are two independent chain rotors being rotated in opposite directions. The direction and speed of rotation of the rotors, the spacing of the rotors, and the careful management of the material flow path through the machine all contribute to the high efficiency of the J&H HD Chain Mill. Solid welded construction and wear resistant impact pads and liners, and a unique suspension and vibration isolation system provide exceptional durability and life to the chain mill. Large doors on the chain mill provide complete access to the rotors for inspection and maintenance. Several chain mill sizes are available to match the capacity requirements for the application.
The efficiency of the J&H Chain mill comes not only from the correct rotor velocity, but also on the configuration of the chains on the rotor. J&H has standardized rotor design to hold the required number of chain links for the selected Chain Mill machine size. Proper chain spacing allows some of the material to fall lower into the path of the chain links before being impacted. The J&H Chain mill’s dual rotor configuration also promotes multiple impacts of the material as it is propelled through the mill. The number and configuration of chains on each rotor has been determined by J&H to maintain balance of the rotors, and to increase chain life by distributing the material impact over a larger area of the chain. This results in increased mill efficiency while reducing maintenance.
The unique and innovative feature of the J&H MOD III HD Chain Mill is that the rotors are completely supported and driven from one side of the machine. This configuration of the J&H Chain Mill permits large access doors on the front and sides of the machine for very easy access to all of the necessary points that need to be reached for service. It places all of the mechanical parts of the machine on one side for easy inspection and evaluation of mechanical systems. General maintenance of the mechanical system is easier and more efficient.
The inboard bearings, which support the majority of the weight of the rotors, are soft mounted on rubber rails, allowing the shafts to independently respond to the forces of start up and shut down as well as the many material impacts that occur when the machine is in operation. The flexing of the rubber rails against the rigidity of the support structure absorbs the motion of the rotor and dissipates the stresses generated in the shaft. This takes the loads off of the rotor bearings, increasing bearing life. Vibration forces that are common for most chain mills are dissipated and reduced to a negligible amount in the frame of the J&H HD Chain Mill. The advantage is that the J&H MOD III Chain mill does not have to be isolated from the plant building structure and can be mounted directly to concrete floor curbs using standard anchor bolts.
In this series of photos, it is good to note the following: 1) The chain mill is running at full speed as evidenced by the extended position of the chain links, 2) The chain mill is not anchored down in any way. The machine is sitting free on the concrete floor of the shop, and 3) notice that the photo of the cup of water is an enlargement of the cup sitting on the middle top of the running machine. You have to look very closely at the water in the cup to see any ripples at all. The J&H Chain mill is dynamically balanced and produces almost zero vibration when operating normally. The design of the cantilevered rotor shaft and the rubber floating bearing absorb nearly all of the vibrations that are generated by the rapidly spinning rotors.
If plant floor space is a concern, check out our more compact HDS / HDF Chain mill designs.