Systems, devices, methods for delivering hydrogel compositions with self-purging to prevent clogging
A hydrogel composition is formed by conveying separate first and second liquid components subject to a selectively applied application pressure P(A) into an outlet path for mixing and discharge. A liquid flushing agent is automatically conveyed into the outlet path subject to a substantially constantly applied purge pressure P(P) when the application of P(A) is interrupted, to continuously flush residual hydrogel composition from the outlet path.
1. A self-purging delivery apparatus for a multi-component composition, the delivery apparatus comprising:
an applicator comprising two or more interior channels each for separately conveying one of the components and an outlet path which is fluidly connected to each of the interior channels to facilitate mixing of the components therein;
a multi-barrel syringe, wherein each barrel defines a reservoir, and each barrel is coupled at one end to one of the two or more interior channels of the applicator;
a single actuator coupled to each barrel such that application of an application pressure P(A) causes each component to flow simultaneously from each reservoir, respectively, to the interior channels and the outlet path;
a purge assembly comprising a source of liquid flushing agent, under a constant pressure P(P), fluidly coupled to the applicator's outlet path via a purge path to convey liquid flushing agent into the applicator; and
one or more pressure-sensitive valve assemblies operatively coupled to selectively close the purge path when the application pressure P(A) applied via the actuator is greater than the constant pressure P(P) of the source of the liquid flushing agent.
2. The apparatus of claim 1 , wherein the purge path is coupled to the outlet path at a location where comingling of the components occurs.