The Alquería paper mill is a company located in the province of Alicante, whose activity is the manufacturing of paper from recycled material.
It has recently considered an advance in its energy supply under an environmental improvement action plan, aiming to obtain energy in a cleaner and more efficient way.
The Catalan company L. Solé carried out a design study for a plant generating pressurised steam from the combustion of biomass in order to totally or partially replace the steam used by the company in its internal processes, which is generated by natural gas boilers.
In the design of the above company collaborated bridge crane manufacturers with G.H. and the clamshell grab manufacturer Stemm. The goal was to generate a steam flow of 30 MT/hour with a steam pressure of 14 bars, using wood chips and waste from the local timber industry as fuel, as well as forest and fruit biomass from the region.
This would save 10% in electricity consumption, which was initially 1000 MW/hour/year, and 95% in natural gas consumption, which was 420,000 m3/year, subsequently saving of 1,300 MT/year of CO2 emissions.
Total safety in the operation of the grab was required, with no breakdowns, no stoppages and a sufficiently high and optimal dragging and loading capacity, which should never fall below 4 m3 .
The chosen clamshell grab was a 2CH-4000-1,1 type specially designed for this type of processes, with adequate closing and emptying times to achieve maximum performance in the plant, as was later confirmed during the start-up, with outcomes in terms of load takings considerably higher than those initially foreseen.
The clamshell grab has an automation kit with safety and signaling peripherals that are necessary to work in an automatic process of 24/24 hours, without the operator being present.
Amongst the most noteworthy components are: the electric oil level combined with a signal horn and alarm signal emitter via wifi, thermostats, anti-condensation systems in the hydraulic group of the grab, phase and rotation control of the electric motor, PTC/PTB thermistor motor probe and, of course, a series of indicator lights showing the state of the manoeuvre at all times.
The grab was equipped with the internal GRAB CONNECT automaton which constantly monitors and secures all operating parameters and even enables preventive maintenance actions.
This STEMM clamshell grab belongs to a newly designed, state-of-the-art series that has been installed for several years in other recent installations in the Nordic countries.
