Know How

Lower investiment, much lower energy consumption, easier startup and shutdown

DGC granulation plants are particularly suitable for high, medium-high and medium density powders, ranging between 700 and 1000 g/l, depending on the formula and raw materials specification. The product obtained is a free flowing, dust-free detergent powder of very constant granulometry, in line with the most modern market trends of "compact" or "ultra" products. The products which can be obtained are: washing machine powders, hand whashing powders, dish washing powders, scouring powders. DGC plants can be operated 1, 2 or 3 shifts per day and they do not produce any liquid affluence while exhaust air is purified by a filter to permit its free discharge into the atmosphere, even in situation of tight environmental regulations.

A special feature of the DGC plant is to abstain densities as low as 700g/l

If desired, DGC plant can be placed, with some modifications, in conjunction to an existing spray drying plant, to increase the production capacity as well as the formulation flexibility. The DGC plant produces synthetic detergent powders using the agglomeration-granulation technology, consisting of neutralization of LABS with sada ash (sodium carbonate) and other alkaline raw materials in a Continuous Granulator - Agglomerator - Neutralizer. Other powder (builders and filers) like zeolite or the humid granules are there dryer in a fluid bed dryer. After it there is a post-addition section for the incorporation of thermo-sensitive materials,like perborate,enzymes,etc.

Typical process description

The following in the description of a typical plant although it is then normal to adapt it to satisfy every single customer requiements. Powdery raw materials (sodium carbonate, sodium sulphate, sodium tripolyphosphate or zeolite) are pneumatically tranferred to relevant silos. A premixture of minor ingredients is prepared in a mixer and traferred to its storage silo. Each silo is complate with a bag filter, to recover fines from exhaust air. Powders are ectracted from storage silos using different systems depending on plant capacity. On solution is buy extraction-dosing belts which measure with precision all components onto a belt conveyor. They are then discharged inside the Continuous Granulator - Agglomerator - Neutralizer together with liquid raw materials (LABS, sodium silicate, water, non-ionic solution,etc.), dosed with great accuracy directly from storage thanks using positive displacement pumps and mass-flowmeters. The granulation process is an aggregation of powders obtained by spraying over them some liquid components that act as binding agents: larger particles are obtained and therefore a density different from the one of starting powders is reached. The operation is done inside a special machine: the Continuous Granulator - Agglomerator - Neutralizer. Inside it, special rotating blades are responsible for the even distribution of liquids over the powders and to keep the granules dimensions constant and controlled. Sulphonic acid is neutralized by sodium carbonate while sodium silicate solution and other solutions act as aggregating agents. Others powdery raw materials fed to granulator are evenly dispersed by the vigouros agitation of its mixing-dispersing blades. At this stage a "compact" high density powder base is obtained (density 700 - 1000g/l). Then the mass is fed to a fluid bed where detergent granules are dried by the action of a hot air stream and then cooled by a cold air stream. The detergent base is raised by a bucket conveyor and can be additivated with heat sensitive materials like perborate, enzymes, non-ionic, perfume, etc. An electronic control system controls all dosing devices to ensure that all flowrates of additives are consistent witn the requested formulation. Powders and liquids, like perfume and non-ionic detergent, are blended inside a rotatong mixer. At the end, lumps are separated by a vibrating sieve.