These grabs work at a different speed depending on the resistance they find when manipulating different products, diverse and mixed.
STEMM has developed a new range of state-of-the-art grabs. Smart Grabs that during each handling process automatically adapt themselves to the product specific characteristics with no direct manual intervention from the worker required.
Should the product be heavy or compacted, of big granulation or sometimes mixed with light products or plastic packages, the grab works at a lower or higher speed, regulating the penetration force required and with the adequate dragging of the material; it changes the speed and regulates the pressure according to the material characteristics in each moment.
It is basically a very special hydraulic circuit, that coordinated with an automaton allows for the regulation of pressures, time-delays, and combination of various parameters.
The working mode of the machine can previously be programmed according to the products and materials that are going to be handled. This programming is done on remote, either from the crane cabin or via a remote control from a tablet, PC or smartphone.
The grab’s operating regime can be known and controlled on remote, obtaining data of the number of fast and slow manoeuvres that are carried out during the homogenization and preparation phase, and therefore gaining a considerable amount of time.
Stemm’s Smart Grabs feature external signalization with lamps running on fast or slow flashes frequency and colours depending on the condition or working regime at each moment.
Handling with STEMM’S last-generation grabs provides significant added value. These grabs are highly appreciated in the following sectors:
Incineration lines are fed by waste handled by electrohydraulic grabs installed hanging on cranes bridges. From the pit the mixed residues are manipulated to feed the hoppers, but first it is necessary to carry out continuous operations of homogenisation and preparation of the surfaces, prior to feeding of hoppers and conveyors. Since granulometry, density and composition of the various materials are different, different penetration, drag and speed processes are required.
The qualitative advantage of using Stemm’s smart grabs is specially appreciated when handling plenty of light residues, plastics, packages … in this case great penetration force is not needed, and rapid and agile maneouvres are achieved.
Before the combustion in the boiler, biomass requires a previous preparation process. The product is homogenized, uniformizing, mixing and adjusting the granulometry and the degree of humidity so that the boiler receives a constant energy flow of similar value, which will facilitate the combustion and reaction process.
Grabs will work adapting to the various materials, compositions and granulometries that are found in the preparation phase.
In scrap yards there are stored various types of scrap with very different densities and granulometries, such as chips, fragmented scraps, light metal waste, OA and structural scrap....
Handling times, preparation and homogenization of scrap yards, as well as baskets loading times will be very different for each range of scraps.
When handling light chips, components and additives, the required penetration forces will be lower and therefore the manoeuvres times will be faster and more agile, optimizing handling times and thus saving significant time that will impact production processes.
After crushing the limestone and clay at the quarries they are transported to the processing plant where they are gradually mixed until the suitable composition (depending on the type of cement sought to be made) is reached.
During the mixing process in the pit, various irregular areas require different force and dragging treatment.
In the cement manufacturers process there is an important stage, the grinding of the raw material, for which an appropriate homogenization and mixing treatment of the raw material is required.
Port cranes are equipped with various grabs for handling various types of bulk of different densities and granulometries. As not always the most suitable equipment for each bulk is available, equipment with grabs that cover the maximum and higher range of material densities.
This entails higher closing times, with penetration forces that are not always so necessary; In short, the result is very slow and long boat unloads.
When the bulk carried in the hold is lighter, the manoeuvre times are automatically adapted with the appropriate penetration force and speed, resulting in great time savings in the unloading of the boats and therefore a major economic impact for port dockers.
Source: STEMM