Kjeldahl Bulb, Borosilicate Glass

A Kjeldahl bulb — the pear-shaped glass bulb fitted between a boiling flask and a condenser to trap droplets carried up by the vapour, so that only clean distillate reaches the receiver.

• Borosilicate glass, resistant to thermal shock
• Traps splashes and entrained droplets during distillation
• Used in Kjeldahl nitrogen determination and in general distillation setups