Aspirating a mill and removing the ground product are almost as important as the grinding itself. The hammer mill requires a certain amount of air so that the ground product can be transported out of the grinding chamber and cooled during the crushing process; the ground product should be supplied and extracted under controlled conditions. The Tietjen grinding module therefore not only includes the hammer mill but also the grinding material metering, the aspiration, the discharge of the ground product and, where necessary, measures for explosion protection. This means that all components are carefully co-ordinated with each other to ensure optimum interaction in the grinding process.
Precise control with a user-friendly interface is of great importance in order to fully utilise the performance of a system for different products and to ensure its optimum utilisation. We incorporate our procedural expertise into process automation and manufacture tailor-made control cabinets with corresponding process visualisation. The fact that everything comes from a single source means that there is no loss of information. The procedural and process technology are optimally coordinated with each other.
Whether for piece goods or bulk material, in dry, liquid or gaseous form, the main requirement for conveyor systems is safe, careful and energy-efficient transport as well as precise dosing within a load-dependent process. At Tietjen, we focus on our core competence: conveyor systems and dosing machines for systems to process natural substances. We offer mechanical, pneumatic or hydraulic transport.
Our hammer mills are considered reliable and durable. Tietjen has been synonymous with quality for more than 60 years. We have already delivered more than 2,100 systems for tailor-made plants worldwide and even added impact classifier mills to our programme in 2018. From simple self-feeding grinding systems for small operations to computer-controlled large chamber mills with automatic screen change for 24/7 operation. Fineness ranges from > 3 mm to 150 microns. The machines are in operation throughout the world under a wide variety of conditions. They are robust, built to be maintenance-friendly, and specially designed to be extremely energy-efficient to operate. Our drive power varies from 11 to 450 kW. Tietjen’s mills perform a variety of specific crushing tasks. We have the right mill for your product as well – contact us.
Aspirating a mill and removing the ground product are almost as important as the grinding itself. At Tietjen, we provide the appropriate in-house filtration and the right screw system or pneumatic conveying system for every application and type of mill. Process design and explosion protection are just as important as energy efficiency within the grinding system. That is why, here at Tietjen, we address different pressure and flow conditions in the grinding module, the incoming flow in the Tietjen filter, various filter materials and the optimal design of the filter – from the filter type and model to the individual nozzle for cleaning. We know that a system can only be as good as the quality or sum of its individual components.
The volume and shape of our Tietjen receptacle (also called a plenum or trimelle) are customised to meet your unique product characteristics, the mill used and the on-site spatial conditions. A tailor-made container is important to prevent bridging, ensure pressure shock resistance and guarantee a low flow speed towards the filter. It also serves as a frame for the explosion protection relief valves. Tietjen’s upstream containers are always individually tailored according to batch size. Below the container are the screws for the safe removal of the grist as well as the rotary valve for decoupling.
We are able to offer the right grinding module for every application and mill type, always taking into account the product properties, the available space in the facility and explosion protection.
Therefore, there are two concepts for the grinding module: With mechanical discharge and with pneumatic discharge. Both systems are of identical design up to the hammer mill and typically consist of an upstream container, feeder and mill.
In the case of mechanical discharge, the ground product is collected in a container beneath the mill. A low air velocity has the effect that dust particles are able to sink and therefore the dust load on the filter is reduced. The filter can be found directly next to the mill on the secondary container. A fan generates the air flow for aspiration.
The ground product and the cleaned filter dust are mixed using a discharge screw and transported out of the secondary container. A rotary valve at the outlet of the screw conveyor ensures that the air is sealed off.
Where pneumatic discharge is used, the crushed product is extracted below the mill by the aspiration air into a filter. In this case, the filter does not have to be positioned directly next to the mill, allowing the material to be transported pneumatically over longer distances. A fan also generates the air flow for aspiration and conveying here. After the product-air mixture has been separated in the filter, the ground material is then discharged via a rotary feeder.
Both systems can be equipped with components for explosion decoupling to the upstream and downstream process as well as in the pneumatic conveying line in the case of explosive materials. Measures for explosion pressure relief round off the safety concept.
“We carefully coordinate the components for you to ensure that they work together in the best possible way in the grinding process.”