ISOLATION THERMIQUE DES VEHICULES CALOPORTEURS

摘要

Ducts in an inaccessible underground gallery are thermally insulated by injecting at intervals into the gallery a foaming compsn. comprising a phenol-formaldehyde precondensate which forms an emulsion with a hydrocarbon of b.pt. 20-45 deg.C using a polyoxyethylene-fatty ester as emulsifier, and which contains a polymsn. initiator in amt. such that it is completely consumed after polymsn. The injected compsn. has a significant swelling and creaming time, but has short polymsn. time. It is injected at at least 15 deg.C and the duct in the dug-out has a temp. of at least 20 deg.C at the moment of injection. For insulating e.g. fluid conveying pipes. The process allows insulation to be carried after the pipes have been laid. The foam used can fill up all gaps between the gallery and the ducts before hardening occurs.