Patent ID: 7237581

Claim:
A chemical solution dispensing apparatus, comprising: a supply vessel in which solution to be dispensed is stored; a buffer tank having an inlet and an outlet, the supply vessel being connected to the inlet of the buffer tank such that solution flows into the buffer tank from the supply vessel in the apparatus; a pump having an inlet and an outlet, the inlet of the pump being connected to the outlet of the buffer tank so that the pump is operative to pump solution out of the buffer tank through the outlet of the buffer tank; a filter unit connected to the outlet of the pump so as to receive the solution pumped from the buffer tank, said filter unit having a filter that filters the solution issuing from the outlet of the pump; and a bubble removal filter interposed between and connecting the outlet of the buffer tank and the inlet of the pump such that solution passing from the buffer tank passes through the bubble removal filter before flowing into the pump, said bubble removal filter being configured to remove air bubbles from the solution before the solution flows into the pump.