I notice a strange behaviour of molten glass droplet chute into polluted water pool.
the first droplet of 1600 C 25 kg molten glass rapidly cool down in polluted water and heat up polluted water considerably.
but second, third, forth, ... droplet drop into the same spot of solid Glass won't add up the heating progress.
50 kg solid glass rapidly cool down at the very same rate to 25 kg solid glass
even when the first 25k solid glass cool down to 50 C , dropping more 1600 C 25kg molten glass won't increase temperature. not even 0.1 C
I avoid it. VIA clearing old batch of solid glass before droping new molten glass droplet.