Home › B.Tech Civil › civilengineering › Concreting Equipment › Liquid nitrogen is used as an alternate cooling …
Liquid nitrogen is used as an alternate cooling agent. The unit gives its boiling temperature as approximately:
Answer & Solution
Correct answer: D.
1. Liquid nitrogen is an inert cryogenic fluid used to chill mixing water and form ice.
2. The unit reports its boiling temperature as about −196 °C.
3. At a batch plant, liquid nitrogen lances inject directly into the water storage tank.
4. This brings the mixing water down to about 1 °C before charging the mixer.
5. The other temperatures misstate the boiling point of liquid nitrogen.
_Source: IGNOU Concrete Technology, Unit 7 "Concreting Equipment" (Mixers, Cableways, Batchers, Buckets, Pre/Post Cooling)._
Related questions
Refrigeration plant capacity for pre-cooling of mass concrete is expressed in tons of refrIn the heat-balance equation, the specific heat of cement is generally taken between:In the heat-balance equation Eq. 7.2 for ice quantity, the latent heat of fusion of ice isIn the post-cooling pumping plant, each pipe coil is supplied at a flow rate of approximatThe unit specifies that individual embedded pipe runs may range from 180 to 360 m, with a Embedded post-cooling pipes carry circulating cool water through hardened concrete. The unCement is normally batched dry. To avoid moisture condensation that would adversely affectVacuum cooling of aggregates uses the lower boiling point of water at sub-atmospheric pres