Drop Bottom Furnace

We are building a drop bottom furnace of maximum temperature 1600'C in which heating elements used are Super kanthal (MoSi2) . First the charged material is lifted to be introduced into the furnace from the bottom and then the temperature is raised to 1600'C whereafter the temperature is gradually lowered to 700'C when the charged material is suddenly lowered into the open atmosphere to give it a thermal shock . But this process may damage the fragile heating elements which also get a thermal shock by way of introduction of cold air into the furnace .

What is the way out ?