Meaning: Membranous structure that functions as the circulatory system in mammal embryos until the heart becomes functional. Classified under: Nouns denoting animals. Synonyms: umbilical vesicle; vesicula umbilicus; vitelline sac; yolk sac. Hypernyms (vesicula umbilicus is a kind of...): sac (a structure resembling a bag in an animal)
electric fan; blower. Hypernyms (blower is a kind of...): fan (a device for creating a current of air by movement of a surface or surfaces) Meronyms (parts of blower): electric motor (a motor that converts electricity to mechanical work) fan blade (blade of a rotating fan)
Wall blowers are used to clean the furnace walls and will probably use approximately 2,200 to 2,300 scfm. Wall blowers normally operate in one or more pairs depending on the overall cycle. Their basic job is to reduce slag that has accumulated on the pipes in the upper levels of the boiler, and superheated region.