Authors: Lars Hovda, Martin Fitje from SMV A/S Topics: pot room vehicle design, improving logistics, hot bath crushing, anode milling, anode beam repair, anode transportation Published by: GMC Ltd. in Aluminium World Journal
71 AWJ 2013 FRESH THINKING FOR A BETTER WORKING ENVIRONMENT AND IMPROVED EFFICIENCY The most important element for smelters around the world today is qualified personnel. Today a modern smelter has a high focus on security and good working conditions for their employees. Further, there are several other areas which can be improved with regard to safety, the working environment and process performance. SMV has worked in close co-operation with our customers for more than 55 years and have developed concepts which have contributed to achieving these improvements. As a supplier it is essential that we remain conscious about the developments that are taking place, and continue to actively contribute with good solutions to the challenges emerging from an ever evolving market. As an example for this, I would like to mention one project we had some years ago. A customer contacted us and wanted to discuss how they could improve upon one specific type of pot room vehicle they were using in their operation. With regard to this vehicle, they were weighed down with heavy maintenance costs as well as a higher incidence of sick leave compared to operators on other vehicles. Together with our customer we discovered the areas with potential for improvement by using the maintenance log. We made a new design to accommodate the working tools more efficiently and focused on improving the ergonomic factors the client was having issues with. The modifications we made on the vehicle, for delivery to the client, were: Installing hydraulic suspension on all the wheels, Equipping the cabin with an air suspended operator chair mounted on a hydraulic rotating table to ensure correct orientation towards the working area. After some months of operating the upgraded vehicle we delivered, it was discovered that sick leave related to neck, shoulder and back problems had been more than halved. After one year in operation the findings demonstrated that the maintenance costs were also more than halved. The strong focus given to these important factors contributes to a better working environment, as well as enabling the investment made to pay it itself off in a short amount of time. In the last few years we have seen a considerable extent of involvement from the people involved in executing the day-to-day tasks, such as maintenance, vehicle and process operators. This change has been very positive and we can conclude that it contributes to better products from us, and a greater sense of ownership from the customers side. In the following I will present some of our concepts that have been developed very much in the same way with good customer involvement, combined with the creativeness of our skilled staff. Reduce HF and improve working Conditions with the Hot Bath Crushing system (HBC) In aluminium production hot baths are produced through the operation of changing anodes. Most smelters today focus on how to reduce HF emissions, improve working conditions, effective utilization of the buildings areas and effective logistics. SMV Hot Bath Crusher is designed to receive grabbed bath from the anode changing operation. The first two hours are are especially important with regard to HF emissions, and it is critical to bring the bins with hot bath to the HBC as soon as possible after anode changing. Hot Bath Crushing System
Transcript
71AWJ 2013
FRESH THINKING FOR A BETTER WORKING ENVIRONMENT AND IMPROVED EFFICIENCY
The most important element for smelters around the world today is qualifi ed personnel.
Today a modern smelter has a high focus on security and good working conditions for their employees. Further, there are several other areas which can be improved with regard to safety, the working environment and process performance. SMV has worked in close co-operation with our customers for more than 55 years and have developed concepts which have contributed to achieving these improvements.
As a supplier it is essential that we remain conscious about the developments that are taking place, and continue to actively contribute with good solutions to the challenges emerging from an ever evolving market. As an example for this, I would like to mention one project we had some years ago.
A customer contacted us and wanted to discuss how they could improve upon one specifi c type of pot room vehicle they were using in their operation. With regard to this vehicle, they were weighed down with heavy
maintenance costs as well as a higher incidence of sick leave compared to operators on other vehicles. Together with our customer we discovered the areas with potential for improvement by using the maintenance log. We made a new design to accommodate the working tools more effi ciently and focused on improving the ergonomic factors the client was having issues with.
The modifi cations we made on the vehicle, for delivery to the client, were:
Installing hydraulic suspension on all the wheels,
Equipping the cabin with an air suspended operator chair mounted on a hydraulic rotating table to ensure correct orientation towards the working area.
After some months of operating the upgraded vehicle we delivered, it was discovered that sick leave related to neck, shoulder and back problems had been more than halved. After one year in operation the fi ndings demonstrated that the maintenance costs were also more than halved.
The strong focus given to these important factors contributes to a better working environment, as well as enabling the investment made to pay it itself off in a short amount of time. In the last few years we have seen a considerable extent of involvement from the people involved in executing the day-to-day tasks, such as maintenance, vehicle and process operators. This change has been very positive and we can conclude that it contributes to better products from us, and a greater sense of ownership from the customers side.
In the following I will present some of our concepts that have been developed very much in the same way with good customer involvement, combined with the creativeness of our skilled staff.
Reduce HF and improve working Conditions with the Hot Bath Crushing system (HBC)
In aluminium production hot baths are produced through the operation of changing anodes. Most smelters today focus on how to reduce HF emissions, improve working conditions, effective utilization of the buildings areas and effective logistics. SMV Hot Bath Crusher is designed to receive grabbed bath from the anode changing operation.
The fi rst two hours are are especially important with regard to HF emissions, and it is critical to bring the bins with hot bath to the HBC as soon as possible after anode changing.
Hot Bath Crushing System
72 MATERIALS HANDLING AND TRANSPORTATION
Once the bins with hot bath are tilted into the HBC the process starts automatically, the fumes are extracted into the suction/scrubber system, the material is crushed down and distributed onto a covered cooling conveyor. The length of the cooling conveyor is determined depending on the capacity needed and what temperature the second stage fine processing can handle.
This system is suitable for reducing fluoride emissions, substantially reducing the amount of bins in circulation, freeing up expensive cooling areas for bins as well as reducing the need for handling equipment and operators in the recycling process.
Improve Anode Consumption with the Hot Anode Milling machine
In Aluminium plants with pre-bake technology, peaks can occur under the anodes in different conditions. This can occur on start-up of the pots, thus lowering anode quality and having an adverse effect on the operation and tuning of the pots. The resulting deviations can present as
"mushrooms" or peaks in appearance, or as a generally uneven surface on the anode blocks underside. In both cases these deformations disturb the electrolysis and should be removed.
Normally the troubled anode is taken out and replaced, or the anode is taken out and an attempt is made to remove the deformation by dragging it over the fl oor, usually with limited success.
To secure optimal utilization of the carbon block, SMV have designed the Hot Anode Milling Machine, and since 1985 we have delivered over 32 machines. The principle of operation is that the machine is moved to the pot where the troubled anode is, and the anode is placed into the milling area of the machine by crane or anode changer vehicle. The milling operation takes approx. 4-6 min, after this the anode is put back with a clean and uniform surface. The total time outside the pot should not be more than 10-15 min. and the disturbance of the process and heat loss is minimal for the pot.
The operator is sitting inside the cabin with full overview of the milling and with no exposure to the fumes and heat.
Safe and effi cient Service - Inspection on pots and pipes with SMV Service Wagon
At the top rack over the pots, there are several components which need to be inspected or replaced regularly. Further, most smelters also employ the feeding of oxide trough wall mounted pipes which have to be cleaned or replaced.
The SMV Service Wagon is a small and fl exible vehicle and can be operated by one operator. The service wagon is equipped with a operator basket and a service crane. The platform is
raised and aligned to face the pot, and the crane enables lifting components from the fl oor/ vehicle to the top of the pots.
All movements of the crane and platform are performed from the remote controlled panel. It is designed for effective and secure performance and gives the operator a chance to execute the work in a safe way.
Reduce voltage drop with an Effective Anode Beam Repair System
After some time as the contact surface between the anode beam and anode stem becomes damaged, it is most important to have a smooth surface to avoid voltage drop. SMV have developed a system for the milling and welding of anode beams. The work can be performed inside pot rooms or in the service area for cell reparation.
The system is tailor-made for each customers needs and can be equipped with one or two milling heads, for dual milling/welding or single milling/welding operation. The equipment is hooked onto the anode beam with a crane or a forklift, and is operated from a remote control panel.
Before milling
After milling
SMV service wagon
Anode milling machine
73AWJ 2013
Effi cient Logistics with SMV Anode transporters
Considerable masses of new anodes and used butts are transported. For most aluminium plants these operations represents high costs due to the wear and tear of the fl ooring.
SMV’s Anode Transporters are easily maintained, and their advanced suspension system reduce the damage on floors. The anode transporters consists of a standardized truck with a tailor-made trailer for different customers. The operator has full control with a direct view to the loading/unloading of pallets. If required the wagon may be equipped with covers.
By Lars Hovda, SMV A/S
COMPANY PROFILE
SMV was founded in 1958 and has a wealth of experience as a supplier to a variety of markets. What began as a company supplying the local market in the Sunnhordland region in Norway, has now grown to encompass a range of products and services provided to the local, national and international markets.
Today, SMV is a multi-disciplined company working within the fi eld of industrial mechanics. Our various departments - including development and construction, machining, installation, testing, surface-treatment and service -, make it possible for us to provide packages covering everything from entire projects to smaller, individual sections.
By using modern design and construction programs our engineers perform design of vehicles, stationary machines for Potrooms, and rodding and bath recycling solutions created especially for the aluminium industry.
SMV has long experience with training, start ups, maintenance and preventive service on electro hydraulic machines / equipment. This work is performed both in-house at SMV or on site at Customer facilities (incl. mechanical, electrical, hydraulics, pneumatics). SMV has a number of strategic business partners that complement us in areas such as prefabrication of steel, automation and material transportation.
