HP-STM: Tumbler screening machine

Optimum screening results

The HP-STM is used for the highly effective separation of powdery materials into an upper and lower particle size fraction. Depending on requirements, the HP-STM can also be configured so that the sample can be fractionated into three or more particle size classes. Typical applications for the HP-STM are the classification of recycling materials, but the machine can also be used for other sample types.

The HP-STM is a tumbler screening machine with a circular design. The product to be screened is fed centrally and continuously onto the screen and is then distributed uniformly from the inside to the outside. The movements of the machine are infinitely adjustable and can be optimally adapted to the properties of the sample material. This makes it easy to set the discharge speed, retention time on the sieve insert and sieve material speed, for example, in order to achieve the desired separation efficiency and processing times. 

For special samples, an ultrasonic unit can be used to keep the screen mesh open and to separate the sample material more effectively (optional). The use of ultrasound not only increases the sample throughput, but also improves the screening accuracy. 

Perfectly suited for fully automatic operation

The HP-STM has been designed and optimized for fully automatic operation in a robot automation system. The material is fed in via a rotating discharge unit, which enables targeted, low-dust and uniform discharge onto the sieve. The extraction hood installed above the discharge unit effectively removes the released dust. 

Top and bottom particles are collected in separate sample cups and weighed in the machine (optional). This allows any material loss to be precisely determined. In addition, the quantity of top grain can be used to decide whether further comminution of the top grain and a new screening process are necessary. This enables time-optimized processing of the sample material. Lifting devices under the cups ensure that no material is lost from the discharge hose and feed nozzle, but remains completely in the sample cup.
 

Efficient cleaning and contamination prevention

The HP-STM has highly efficient cleaning mechanisms. After completion of the sieving process, the feeding unit, sieving machine and outlet hoses are cleaned using compressed air and simultaneously exhausted. Vibrators in the area of the feed nozzles and hoses also ensure that any material residues are removed. In addition, the surfaces of the input hopper are coated according to the type of material in order to prevent possible build-up in this area.

If an ultrasonic system is available, it can also be used to remove residual material from the screen mesh. Overall, this prevents cross-contamination of subsequent samples and maintains screening efficiency at an optimum level.

High maintainability and occupational safety

The HP-STM is characterized by its ease of maintenance. All components are easily accessible inside the generously dimensioned frame through the large machine flaps. The functional unit on the base of the sieve, which is used to control the sieve performance, is also easy to reach, allowing for uncomplicated adjustment.

The screens installed in the HP-STM are easy to remove for inspection and maintenance purposes. The sieve shaker can be opened and closed without additional tools using the built-in quick-release clamps. Removal and insertion of the screen is possible without great effort.

When designing and selecting the installed components, we placed the highest value on occupational safety. The installation of the sieve in a frame further reduces the already low noise level, so that comfortable operation in a laboratory is possible. The numerous extraction points minimize dust pollution.