TPT May 2017

AR T I C L E

Rivit SpA

To obtain the diagram shown in Figure 4, certain perfor- mances have been assumed in the industrialised process that decrease with the increasing number of tubes per cycle. In conclusion, HFree Life Pickling has developed an eco- industrial process that entailed remarkable environmental benefits with the complete elimination of the toxic substances and the consequent reduction of the environmental impact. Moreover, the process has achieved excellent production capacities, with possible potential for improvement connected to the chosen plant engineering and a containment of the costs correlated to less energy used compared to the traditional process with consequent benefit, even from an environmental viewpoint.

Pickling time for one tube

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tt “HFree”

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tt “1300R”

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In order to evaluate the production potentials of HFree electro pickling it has been compared with the traditional chemical pickling process, which allows the treatment of one or more tubes simultaneously during the same dive cycle according to its size. The production has been standardised based on the geometrical characteristics of the material that is being treated and this has helped to obtain an average pickling time for tubes and for the more critical alloys. The results are summarised in Figure 3. As can be seen, the ‘HFree’ process for a single tube appears to be very convenient in its treatment of large diameters. The condition becomes critical with smaller diameters where the traditional process allows the treatment of bundles of tubes. For this reason the second stage of the research has been directed towards the analysis of the number of tubes that can be treated in the minimum cycle in the range of diameters shorter than 365mm. Figure 3: Time for one tube in the two processes Pickling time for one tube [h/tube] Pickling time for one tube [h/tube] Figure 4: Time for tube of the two processes in small diameters, Ø<365mm Figure 4 shows the time for small diameter tubes, assuming to treat tubes per cycle. 0-365 365-699 700-800 800-1016 Ø>1016 [mm] 0 1 2 3 4 5 0,8 0,7 0,6 0,5 0,4 0,3 0,2 0,1 0,0 n el [N° tubes per cycle] Pickling time for one tube, small diameters

tt “HFree” tt “1300R”

Rivit SpA 36030 Caltrano, via Andrea Palladio 129, Vicenza, Italy

Fax: +39 0445 359 300 Email: sales@rivit.com Website: www.rivit.com

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MAY 2017