The requirements for throughput rates and fineness in the grinding of pet food and fish feed for extrusion have increased significantly in recent years, while the recipes are becoming ever richer in fat and protein. With the FD 32 Pro hammer mill, Tietjen is presenting a completely new development that has been specially designed to meet these requirements.

Well-known features of Tietjen hammer mills such as robustness, user-friendliness and the smooth running of the rotor have been retained and supplemented with new design features. For example, the rotor diameter has been increased by 100 mm to achieve a higher beater tip speed and the distance between the beater tip and the screen has been reduced to prevent the screen openings from clogging in the case of high-fat contents.

The grinding chamber was extended to 1,600 mm and divided by a center wall so that the screens, each 800 mm wide, are handled easily. Four screens are installed per grinding chamber segment, resulting in a total screen area of 4.8 m² (7,440 in²). A special screen fastening seals the screens so that no oversize particles can get into the product.

Optionally, impact plates can be installed in place of the upper screens, with which the particle size distribution can be additionally influenced in the direction of higher fineness while maintaining a narrow particle size range. Additional impact areas are available on the sides between the screen segments. This means that coarser screen diameters can be used to save energy while maintaining the same product quality.

In daily operation, the FD 32 Pro impresses with its ease of maintenance and economical operation. Large sliding doors on both sides of the machine allow easy access for screen and beater change. Beaters are changed using the beater frame system, which has been well-proven in Tietjen's large chamber mills for more than 40 years. The advantages of this system are quick replacement of the beaters and reduced idling energy of the mill.