Chamber Furnace Loading

Separated, it would increase over all surface area of the material to the heat. Which should cut preheating time. Tiles would not make difference if the stacked the same way.

Stack together as you have described it will take longer for those in the core of the pile to reach temperature.

I would think that stacking the bricks to allow for air flow would render a more uniform and quicker result......

What kind of efficiency are you hoping to gain? Without an answer to that, we can give you zero advice!

Stacking them tightly and burning them as you do now will allow you to get more products per heat. The fact that you need to heat them a little longer may be worth the extra units you get per heat. Stacking them tightly will also mean the middle pieces will be exposed to heat more slowly, and you may fail to heat them enough to ensure they are "done". So you may have units in the middle of a stacked pile which are substandard and may need to be discarded. This would certainly happen if you decided to move the heat time from 4 hours to 3 hours in the interests of "efficiency". On the other hand, if you palletized an open stacked network of units, you could, say, do seventy five units in only 2 hours. This would result in a net gain as you can see.

Traditionally, bricks are stacked openly to allow for uniform heating even through the inside of the pile. Why are you not doing that now? Are they even bricks?

Another point of efficiency would be how long it would take the pile to become vitreous. If you could to it in two hours, and produced only half the bricks because of an open stacking pattern, would the increased handling required be worth the trouble? How about if you produced three quarters of the bricks in that same two hours? Would it be worth the extra work then?

Also, the dangers of open stacking might include the whole pile coming down when you tried to get them out of the kiln. Do you need to cool the kiln before you remove the product? If so, then you should get as much as you can out of every single heat, even if you have to take an extra hour to do it. It would take many hours to cool off a pile of bricks to handle by hand, and that is a dead loss, which come to think of it, is the point of the question.

I think you should do some experiments. Make some both ways. See what happens. Without more information,

<...should go?...>

Increase the insulation, obviously.

What kind of product is it? 1200ºC for bricks looks too high... anyway apart from the type of product and the magnitude of efficiency improvement the practices already said by others in this thread are right, I would add one that is quite important, this is to get appropiate currents inside the chamber for the fumes, so they run though the spaces in all directions. In there, the configuration of the brick piles determine the gap way shape, usually two brick straight and lateral (also lateral currents) is a good practice.

Calcinating means less of oxygen.

1200 deg C is quite high temperature and electric heating is expansive.

Weight of each 200 x 100 x100 piece being approx. 700 grams is not a metal. Could be it is some refractory or other clay.

Better look for option of Direct heating by pipe line gas in reducing atmosphere (by adjusting excess oxygen to stoichiometric value).

Or if the material is capacitive try high frequency capacitive or dielectric heating. This generates heat from inside of job to he heated and more efficient.