The black smoke in lines of rubber mixtures

Once integrated into the mix, the black smoke adds to the rubber different qualities that this alone does not have: abrasion resistance, resistance to stress and dissipation of heat, among others. For this reason, it is no accident that the majority of gums that we see around us are black.

The black smoke occurs normally in the form of pellets to facilitate its handling and dispersion in the mix, with an apparent density close to 0.35 kg/dm³. Although these pellets have a variable hardness depending on the type of black, in most cases their fragility is a drawback to be taken into account. Rupture of the pellet and therefore created fine, cause serious problems of process as well as be able to vary the technical conditions of mixtures. Taking into account the above, Solids System-Technik has developed facilities for automatic handling of this product in enterprises in the market of rubber mixtures.

These facilities include all necessary processes from the download of sacks, big-bag, containers or tanks, storage silos, as well as dosing and feeding to internal mixers. Appropriate automation of these processes is key to reducing production costs, ensure traceability, enhance security and reduce the exposure of workers to unsanitary environments.

It is possible to divide these facilities for the management of the black smoke into clearly differentiated stages: receipt and unloading; storage; pneumatic transport; dosage; loads mineral, plasticizers and polymers, and automation of the process.

Receipt and unloading of the black smoke is the more cumbersome phase in the process and the time in which the workers are exposed to their harmful effects. The low density of the black smoke and the content in fine impalpables do very volatile, so any download or spill caused dust clouds and slum conditions, littering the teams and increasing the costs of cleaning and maintenance.

For sacks of manually downloading we propose the installation of booths ergonomic bags vaciadoras, equipped with filters with vacuum cleaner for the abstraction of the fine in suspension. A variant of these cabins is the solution combined with release of big-bag system.

Download of big-bag bags, Solids System-Technik has developed the watertight and mobile, download head that prevents the emission of dust to the atmosphere and facilitates the complete draining of the big-bag. When the consumption are important, the black smoke can receive in tankers to which Solids System-Technik applicable release Solids Truck Discharge system, to load the storage silos minimizing breakage of pellets. Another way to get the black smoke are trailers container cantilever chairs. These trailers are actually mobile silos and offer an interesting alternative to the bags big-bag and transport with tanks. From container trailers, the firm installs the system of pneumatic transport specific to the silos of daily consumption.

When the black of smoke in pellets loads in silos of storage or in silos of daily consumption, does not present special difficulties regarding flows of download, internal stability or extraction equipment equipment. But this is not like this if the black presents in dust or if during the load of the silos break the pellets by the use of a system of unsuitable pneumatics transport. The presence of fine ocasiona adherencias and apelmazamientos that hamper the flow and the extraction equipment equipment of the silos or even the obstruction of the pipes of exit.

With regard to the conditions of hygiene of the installation, has to take into account the property fuel of the black of smoke and therefore the possibility of generation of explosive atmospheres or fires.

Although the indexes of explosividad of the black of smoke are low (St 1) do not have to despise. Thus, they have to adopt consistent preventive measures in the installation of equipment certified to work in Atex and adecuación of the specifications of the cableado and conexionado electrical, as well as the general measures like maintenance of equipotencialidad, put to earth, etc.

In addition to the measures of prevention, have to adopt measured of consistent protection in the installation of panels or valves of venteo of explosion.

As seen above, the fragility of the pellet of black smoke affects the choice of the pneumatic transport system. Aware of this condition, Solids System-Technik opts in its facilities by the Solids Puls Pneu system. This is a system of careful pneumatic transport, cartridges, made up of the pulsor as pressure vessel, the valve of impetus for the formation of product cartridges, and an auxiliary pipe provided with stations relay, for the conservation of cartridges black during transport.

The Solids Puls Pneu system achieves to minimize the generation of fine during pneumatic transport up to 4% approximately, as are achieved speeds of the product in the pipeline of about 0.5 to 6 m/s in the origin and end respectively.

Another special feature which applied Solids System-Technik in the pneumatic transport of black smoke is the use of pipes special, completing the most favourable conditions for a careful transportation.

The dosage of the black smoke to internal mixers should be characterized by its speed, accuracy and repeatability. With times of cycle even under 3 minutes, recipes of various types of black and runs without interruption, the challenge requires secure systems.

To achieve these three objectives Solids System-Technik has joined all his experience taking the dosage through special spindles of low speed, scales with minimum tara and hoppers of flexible material with integral vibration application. These measures ensures the most high-precision and repeatability.

Guaranteed the reliability of the system of dosage, Solids System-Technik offers the possibility to reprocess the fine of the recuperator, bringing them to the recipe as a partial component, thus putting in value a by-product which generates costs of treatment or disposal.

Rubber mixtures also involve other components such as polymers, plasticizers oils, mineral loads, and other minority. All of them are integrated in automation to take for each system and specific procedure.

Among them are the dosing cabins of plasticizers that Solids System-Technik has been standardized as a result of years of experience. They have entries for 8 different types of plasticisers, Gravimetric dosing, compact construction and aluminium, heated and insulated from the set.

All these processes are controlled from a closet of central command equipped with a PLC of last generation, which governs all the maneuvers of the installation. Also settle tables premises in the area of food of polymers and minority, as well as in the reception area of raw materials which are validated through bars or other procedures code readers.

To monitor, supervise, as well as programming recipes and parameters is implanted an application Scada (Supervisory Control And Data Acquisition), developed by Solids System-Technik under standards but personalized to each user. This application may shoot on one or more local or remote computers.

The Scada system integrates, supervises and monitors, and dosage processes, maneuvers and variables of the internal mixer and later roller controlled by other PLC.

As the culmination of the automation, Scada system communicates and exchanges data and commands with the ERP (Enterprise Resource Planning) system that may exist. This interrelationship is guarantees the traceability recording the tour and made processes products, lots, types of blends, parameters and all the aspects that have to do with the preparation of a mixture of rubber.