Energy Saving with better Performances

Danieli Breda has launched a series of technological packages, some of easy installation even on existing machines, aimed at reducing consumption while maximizing productivity

by Paolo Fraternale, Vice President, Danieli Breda Division

In recent years, global awareness of the environmental impact of both industry, domestic heating and car emissions has reached peaks of attention. In 2017, 17.6% of total energy consumption in Italy (electricity, thermal and transport) is represented by renewable sources. The National Energy Strategy foresees 28% of Renewable Energy by 2030. In the automotive sector all the main players have now turned the page, preferring the electric or hybrid motorization to the Otto or Diesel cycle. The weight reduction, which affects consumption so much, especially during acceleration/deceleration and therefore when driving in the city, has become a leit motif in the design of new land transport vehicles. The same, for years, is also occurring in the aeronautical and ship building sector. The new frontiers have opened up on the use of high-strength steels, to reduce weight, or of light alloys or composite materials. In a closely intertwined world like ours, where the speed of osmosis between one sector and another of the industry has greatly increased, the inspiring principles of the automotive world have also rapidly influenced the world of extrusion. The KERS (Kinetic Energy Recovery System) of the Formula 1 or the Start and Stop device, which we daily experience on our cars, or the Emergency Call, which will be mandatory on the newly registered cars from April 18, are some of the inspiring concepts. Difficult is the need to combine Energy Saving with Performances, because they are usually antithetical. Starting from the concepts presented, Danieli Breda has launched a series of technological packages, some of easy installation even on existing machines, aimed at reducing consumption while maximizing productivity. Following a brief presentation of ESED TechPack.

ESED 4.0 (Energy Saving Electrical Drive): the start and stop of the extrusion? Much more…
The extrusion cycle can be divided into two parts: the extrusion phase and the dead cycle time to load a new billet. During the extrusion, which lasts about 90% of the entire cycle, the main driver is the force, during the dead time it is speed. The force is strictly connected to areas and pressure, the speed to the number of pumps and power of their motors. The force does not therefore depend on the number of pumps installed but on the pressure and the areas, on the contrary of the speed, especially during the dead cycle time. How to say: the number of pumps in excess of those related to the extrusion speed is due exclusively to the dead cycle time, which lasts 10% of the entire cycle.
For this reason, during the extrusion phase the capacity of the not required pumps is set to zero: consumption is reduced and the active pumps are working in the area of the best efficiency / flow-rate regulation. During the dead time, on the contrary, the speed is the driver: it is necessary to maximize the flow to reduce the time lost between an extrusion and the other.
As we said Performances and Energy Saving are often antithetical: few pumps means long dead times, many pumps means increased costs not only for investment but also for operation and maintenance. The Columbus egg had begun to take shape three years ago with the ESED Patent, today it has been refined with the birth of ESED 4.0.

The concept
Do you need a little oil during extrusion, which lasts 90% of the total cycle? Install the number of pumps and engine power as close as possible to the maximum speed you want in extrusion (high pressure). Will I miss oil during the dead time? We increase the number of revolutions of the pump motors to get more oil. Which way? Mounting inverters on the motors, increasing the r.p.m. by 40% during the dead time. That said it may seem trivial, but a series of “consequential damage” arises. What happens to the transients of dead cycle time? How to quickly accelerate the motors, having greater inertia than the pump swish plate? What happens to the maintenance installing motors at variable speed instead of constant?

The solution
Danieli & C. Officine Meccaniche has an average annual turnover of around 2.5 to 3 billion euros. 5% is dedicated to research and development: ESED 4.0 is a child of this investment. In the R & D department of Udine, a Test Bench was set up to test the various possible configurations in the laboratory: type of pumps, pump displacement, engine power, type of inverter…
The tests were carried out by simulating work cycles for different extrusion modes: Cycle for profiles Construction (typically window frames), Industrial Profile Cycle, Cycle for Micro-Multiport and Cycle for Hard Alloys.The ESED 4.0 was born from the mix of the different solutions, which translates into:

• Fixed pumps: Heavy Duty type, almost maintenance free, low investment or replacement cost, easy calibration (not necessary) and maintenance. No proportional valves and pilot pump required.
• Motors: Primary Brand, standard type, high power. Maximum rotation 1500rpm during extrusion, 2100rpm during dead time. No water cooling or square cage. Easy availability for after sales. Well proven reliability.
• Inverter: to overcome the inertia of the industrial motors, a device similar to the KERS has been patented, to give quick response during dead cycle time.
From the above, the problems of inertia reduction, ease of maintenance, optimization of installation and operating costs have been brilliantly solved. But still a substantial gap in oil flow needed, between Extrusion and Dead Time, remained to be solved. To bring the cylinder’s thirst even balanced during the two phases, the press movements that do not require high pressures have been made electric or released from the oil consumption: the loader, the shear and the die change will be implemented by means of drives that do not they require flow to the pumps.
It has been experimentally reached, according to the Product Mix, a reduction of consumption from 5% to 35% and above all an easier and less expensive maintenance (no proportional valve, simpler hydraulic blocks, no expensive revision of variable flow pumps, precision and repetitiveness in the extrusion speed control…) and finally optimization of downtime.

NRG Handling
Up to now we have talked about presses, but for several years now Danieli Breda has become Full Liner: the current market needs have pushed us to extend the know-how to downstream and upstream of the press. The belonging of the DFO (Danieli Ferrè Olivotto, specialist in high performance industrial furnaces) to the Danieli Group, has allowed to design and supply a new family of furnaces with low consumption and reduced environmental impact.
Even the downstream handling has undergone a profound technical review: the recruitment of 9 expert engineers, coming from the most qualified Competitors, has allowed to develop new solutions for:
• Intensive Cooling Box: designed for alloys that require robust cooling at the exit of the press, it has been designed to have a high temperature precipitation rate, reducing its length and ensuring the best metallurgical quality of the profiles. Its length shortening has also a beneficial influence allowing to increase the length available for flying cut, with the same overall dimensions. Higher extrusion speed achievable.
• Electric Train Pullers: they are a real revolution in the puller field. Increased plant reliability and ease of maintenance. One of the pullers can be parked off-line for maintenance and guarantee higher speed control compared to hydraulic motor drive.
• Electric Stretcher: reduces the necessary hydraulic power units and the footprint, guarantees greater precision when stretching profiles and facilitates maintenance.