Professionalisation of the shipbreaking industry

Statistics provided by the NGO, Shipbreaking Platform, in its latest annual report, confirm the importance of South-Asia, China and Turkey in end-of-life ship dismantling.

NGO Shipbreaking Platform

Even though the location of demolition remains unknown for one vessel in five (An Econometric Analysis of Market Dynamics and Industry Trends Sabine Knapp1, Shashi N. Kumar2 and Anna Bobo Remijn3 Econometric Institute, Erasmus University Rotterdam Econometric Institute Report 2007-52 (revised)), international pressure for dismantling to be carried out properly is likely to result in the modernisation of many sites.

An initial consequence of this pressure, which is also linked to the fact that the price of used vessels has more than doubled in the last decade, has been a strong reduction in the number of ships being dismantled: down 50% in 7 years.

Shipbreaking-structure

The processing of scrap material from ships

The scrap obtained from the breaking of ships is in a form that does not allow optimum feeding of furnaces. As well as creating heavy quantities of scrap, torch-cut material often generates 1.5m cubes, filled with empty space (see below). The shearing of this scrap, whose density ranges from 0.25 to 0.4 t/m3 generally allows a higher output density, of 0.6, or even 0.7 t/m3, to be obtained.

Shipbreaking-photo3     Shipbreaking-photo5     Shipbreaking-photo4

The shearing process, in itself, is relatively simple and can be carried out, in theory, using 1000t hydraulic shears. However, the form of the scrap to be cut can make preparation for shearing difficult. For this reason, lateral-box shears are the best choice to break down the volumes created by this “structural” scrap.

Shipbreaking-CIB-cinematique

When selecting shearing equipment for this type of scrap, it is imperative to look very closely at the choice of lateral reducer and lid. Even a 500t lateral reducer, applying a force of 50t per linear metre in a 10m box, will not be enough to crush the scrap.

For duties such as these, we prefer to specify a shorter precompression box of 8m, or even 6m, or for optimum processing a variable-angle lateral-reducer that is able to concentrate power at a single point (the patented POWER-S system).

Power-S     Shipbreaking CIB box with side reducer     Shipbreaking CIB box with power-S system

The position of the articulation and the moment (Nm) of the lid are the other key elements in the processing of this type of scrap. The forces applied to the scrap by the lid in the precompression box will vary, depending on the position of the latter. In a two-stage shearing process, it is imperative to fully cover and compress the scrap, in order close the box; hence the importance of applying a moment that remains high for as long a time as possible.

With this in mind, an alternative is to select a variable-angle lateral-box combined with three-stage processing. The difficulty of reducing these 1.5m cubes to a height of less than 1m is no longer an issue, as a result of being able to introduce material under a lid that can accept materials of heights up to 1.9m.

Today there are many proven technical solutions that can be used to improve the productivity of scrap recovery from shipbreaking operations. The possibility of using this type of scrap without penalising the productivity of furnaces is essential to the future of this industry, particularly in Asian countries and Turkey.

Sujets liés :
http://www.danieli-centro-recycling.com/fr/2011/04/cisailles-bac-lateral-turquie-ouvre-ses-portes-akros-henschel/
http://www.danieli-centro-recycling.com/fr/2014/06/powers/

Crédits :
http://www.shipbreakingplatform.org
http://www.frw.rug.nl/persons/groote/cursus/global%20village/websites/0910/trash/Globalization_of_Trash/Ship_Recycling.html
https://www.osha.gov/SLTC/etools/shipyard/ship_breaking

Coordonnées

Danieli. Plants and equipment for the steel industry

Danieli Team mission is to serve Customers with competitive plant and process technology/automation to produce quality at the lowest depreciation and production cash costs and offer efficient after-sale service. The technology spectrum and relevant process know-how provided by our Product Lines, the well-known tendency towards innovation and high reliability are the best guarantees in reaching this target.

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