Recent content by electr

hehe i know,just put it here for to check them but i check too and found a few mistakes,but tnx

A fuel gas consists of 75% butane (C4H10), 10% propane (C3H8) and 15% butene (C4H8) by volume. It is to be fed to the combustion chamber in 10% excess air at 25ºC, where it is completely burnt to carbon dioxide and water. The flue gases produced are to be used to generate 5 bar steam from water...

thank you both for your help

still i got 35955.33,you did something different?

https://www.physicsforums.com/threads/heat-transfer.913709/#post-5756268 this is the link

ok,i posted it if you have time take a look,and for this question am i correct or should i give it a try again?

Homework Statement Dry saturated steam at a temperature of 180ºC is to be produced in a fire tube boiler from the cooling of 50 000 kg h–1 of flue gases from a pressurised combustion process. The gases enter the tubes of the boiler at 1600ºC and leave at 200ºC. The feed water is externally...

its just my last questions to finish the HNC that's why i m a m a bit impatient to finish

so chest is my solution ok?and should i post the other question too?like i said some other guys already posted it here but still want u to check it

and thank you too haruspex for taking the time to help me

now i see ,sorry my bad, write it wrong... your correct about the Nu= 0.023Re^0.8Pr^0.33 (when i was writing the question saw the laminar value...),so the 90 kw is not the correct one and all i need to do is the q=hΔT for my final answer? and something else chest,i have one more question but...

thank you for your replies,chester what you mean by 0.4 ,i didnt understand it sorry,and for the Q only be Q=6378.183 x (27 - (-23)) =31890915 ??

Re is reynolds number and PR=Cpμ/κ is the Prandtl number...i thought this is a forum to help people not give exams,someone that knows about this can understand what i m doing and don't need to write the equation because i substitude with the values so its the same thing,i see many people don't...

Homework Statement Liquid ammonia is heated as it flows at a mean velocity of 2 m s–1 through a circular pipe. The pipe, which has an internal diameter of 75 mm, is at a uniform temperature of 27°C, and the ammonia at a section 1.2 m from the inlet to the pipe has a temperature of –23°C. Use...

i m just using the calculator from my laptop,and i was getting that result,thank you for your help if there is anything i can help you,just tell me