Question

Calculate a rate of cooling down of air from 80 C to 5C Show calculation. Give an answer in cubic meters per minute and cfm.

Answer 1

Step-by-step explanation:

Given that,

Rate of cooling of air

Initial temperature= 80°C

Final temperature = 5°C

We need to calculate

Using newton's law of cooling

`(dT)/(dt)=c(T-T_(0))`

`(dT)/(dt)=c((T_(1)+T_(2))/(2)-T_(0))`

Where,
`dT=T_(1)-T_(2)`

Here,
`T =(T_(1)+T_(2))/(2)`

`T_(0)` = 25°C (surrounding temperature)

dt = 1 minute

`(dT)/(dt)=c((T_(1)+T_(2))/(2)-T_(0))`

Put the value into the formula

`(80-5)/(1)=c((85)/(2)-25)`

`c=(75)/(17.5)`

`c=4.285\ cubic\ meter/minute`

Hence, This is the required answer.