Carbon Baking Kiln Upgrade

Client

Carbon Cathode manufacturers and supplier

Services / Products

• Baking furnace pre-heat, cooling and exhaust racks
• Design, supply, install and commission
• Control Panels

Scope of Service

Our client in the global aluminium industry needed to upgrade one of their existing plants in order to increase output and meet product demand.

The project involved the design, supply, install and commissioning of new baking furnace pre-heat, cooling and exhaust racks to overcome production constraints by allowing more of the furnace to be in production at any time.

This type of furnace is divided into sections, into which the product to be baked is loaded, and arranged to form a ‘ring’. Baking is achieved by heating and cooling a group of adjacent sections.

At regular intervals one section is added to the group and one is removed from it, which requires all the firing, waste gas handling and cooling equipment be mobile.

To increase output, the number of sections in the group has to be increased, resulting in a higher fuel input requirement.

Therefore, not only did the quantity of combustion equipment in use need to be increased (requiring that the capacity of the waste gas handling system be increased), but also the post-baking cooling capacity needed to be augmented. The three-part upgrade included;

• Pre Heat  - Two classes of combustion equipment are used on this type of furnace, namely ‘high heat’ and ‘pre-heat’, this latter being used on those sections where the temperature is below 750°C. In order to achieve the required output increase we supplied a new preheat rack. This is a portable steel structure is equipped with main and pilot burners, together with a combustion air fan and flexible hose gas connection. A control panel, providing the required burner monitoring and control functions was also mounted on the rack. The design was also configured such that extra burners could be added at a later date if required.
• Exhaust - To cater for the increased fuel input and resultant increased flue gas production, it was necessary to uprate the rack used to connect the lead furnace section to the fixed waste gas system. Since production could not be interrupted for this, a new exhaust rack was supplied. This was a portable steel structure, equipped with connecting and collecting ducts, linked to a waste gas fan, also mounted on the rack. A control panel, containing a thyristor variable speed drive for the fan motor, was also mounted on this portable structure.
• Cooling - Increased output requires increased furnace cooling capacity. Therefore, a new cooling rack was designed and manufactured. This comprised a portable steel structure, on which a cooling fan and the controls were mounted, together with a distribution header and distribution headers to connect to the furnace.

Benefits of our work

• Required increase in output capacity achieved
• Racks were designed, manufactured and commissioned within 10 weeks of order placement.
• Client able to respond rapidly to increased demand from customers