Continuous unit operation
Continuous unit operation means a unit operation where the inputs and outputs flow continuously. Continuous unit operations typically approach steady-state conditions. Continuous unit operations typically involve the simultaneous addition of raw material and withdrawal of the product.
40 CFR § 63.1423
The following terms used in this subpart shall have the meaning given them in subparts A ( 63.2), F ( 63.101), G ( 63.111), and H ( 63.161) as specified after each term: