There are several options when it comes to sanitaryware kiln loading and unloading, and the associated marshalling and storage equipment. Kiln car design also has its part to play.
We take a brief look here at how these systems work and the advances that have been made.
In the traditional system, when the kiln car loaded with fired product exits the tunnel kiln, it is moved laterally to one side of the kiln and is transported adjacent to the kiln on tracks (the return track). At a certain point the car is halted, and the ware is unloaded from the front and back. Further down the return track the car is reloaded and again moved laterally so that it sits ready to enter the tunnel kiln once again.
It would clearly be dangerous to have raised steelwork all the way down the side of the kiln, so the tracks are sunk into a strengthened floor. Additionally, loading and unloading is confined to this area of the factory.
A later alternative method saw the kiln car reduced to about half the width (typically, from around 1.5m to 800cm or so); on reaching the head of the return track the car is then rotated through 90°. Consequently, it takes up far less space, wheels or rollers can be employed to improve manoeuvrability, and the unloading/loading process can be undertaken from just one side.
One of the latest developments is the use of automated guided vehicles (AGVs). Despite the relatively heavy loads involved (typically four to five tons), today’s AGVs can effectively, safely and flexibly transport a laden kiln car to whichever area of the factory it needs to be. This may be away from the production area, used as primitive storage for instance, or direct to where unloaded product really needs to be placed for the next part of the process.
This use of AGVs has a number of benefits:
- Significantly reduced kiln footprint – no return track
- No need for sunken tracks nor return track mechanics, electrics and control
- Speeds up the process
- Uses less energy
- Complete flexibility
Nutec Bickley sanitaryware tunnel kilns also feature automatic car weighing, further optimising load management. We can also incorporate industrial cameras to record images of kiln cars that are planned to be loaded to a pre-defined limit. This real-time visual recorder helps kiln operators to easily identify cars that have been underloaded.
Nutec Bickley has moved away from four-deck loading to two- or three-deck, using wider kiln cars with lower loading. The same loading capacity per kiln car can be achieved, but safety and manoeuvrability are improved.
Firing efficiency is also enhanced as with this system pairs of burners fire both below and above the load. These are installed on opposite sides, and then in the reverse position on the adjacent kiln car, thus generating the ideal turbulence and better all-round firing conditions. We have demonstrated fuel usage reduced by 7% with wider, lower decks.
Nutec Bickley uses updraft exhaust which itself offers a number of benefits. There is generally no need for an exhaust fan; it is simpler as there is less ducting and it’s easier to construct; and cooling is faster with this method. Effective kiln pressure control is still achieved as the pressure is monitored constantly by the system and controlled by a ceramic louver type pressure control damper.
A major contribution to effective sanitaryware loading and unloading is the range of turntables and elevators designed and constructed in-house at Nutec Bickley’s state-of-the-art facility. These allow the customer to achieve optimum loading levels, make it much easier to manoeuvre kiln cars and get them to where they are needed, and to eliminate manual handling.
These are fully automatic systems, enabling the kilns to operate multiple cycles, 24/7, unmanned.
The system can be further enhanced by the introduction of robotic loading.
At Nutec Bickley we are experts in insulation for industrial furnaces and we have an expert team and the latest technology to design your own particular project. Contact our advisory team and tell us about your requirements so that together we can push your operation up to the next level.
Author: Adam Slater, International Sales Director