smokey2007

(see attachment) here is my problem i know the delta temperature i want my nylon to be. with that i can solve for a multitude of things. to start off, this will give me my heat that is required to leave the nylon. however, something went wrong. i am attempting to cool nylon, through stainless steel, and with flowly water on the other side in a series of heat exchange plates. the last part of the attachment shows that when two different calculations are taken place, a different number results (not good). as well as my Nusselt number is way too low. it should be a min of 100. any help would be greatly appreciated on what i did wrong?! heat_transfer2_calcs.txt

i have seen the proof i seek that turbalent flow is more heat transfer efficient. thanx for the right direction.

i appreciate your help, but that did not answer my question so i will give more info like you suggest. the most important aspect is achieving optimal cooling (i could care less about whether or not the fluid is well behaved). the fluid inside of the jacketed wall will be the water. i am currently using a pump with 40 gallons per minute. but i can increase this if needed. mixing does not matter to me one way or the other. i just need something that works, and i am not sure if laminar or turbalent is more efficient. somebody with a PhD in polymer science told me i should avoid laminar because it is not as efficient. but in order to do so, i have to increase my pump size as well as other things. if i did use laminar flow, then i am not sure how to solve for the heat transfer coefficient of the watear. with turbalent flow it is: Nu=.023*Reynalds number^(4/5)*Prandtl number^n where: D refers to the "characteristic length" used to calculate the respective parameter Pr is the Prandtl number n=0.4 for heating of the fluid, and n=0.3 for cooling of the fluid[2] but i do not think the above is accurate for laminar flow. i have looked up and down google looking for an answer to this, so any help would be greatly appreciated.

i am trying to determine if it is better to have laminar or turbalent flow for my problem. i have a hot material (nylon 6) that needs to be cooled. so i will have a jacketed wall (heat exchange plate) that will have water running through it. should i use dimensions that will result in laminar or turbalent flow? also, i am having trouble finding a simple equation to use that involves laminar flow. thanx!

thanx guys, i have my answer now. it was indeed condensing heat. and with the equation Q=mass flow rate*latent heat of condensation everything worked out fine.

say i have a heat exchanger with a capacity of 100,000 BTU/hr. and that steam will be the heating fluid, and oil will be the process fluid. i understand how to calculate for all my needed info for the process fluid. but i am not sure how to calculate the required info for the heating fluid (steam). i want to be able to figure out how to make sure my heat exchanger is working at its full capacity, but i need to know how much steam i need to get into the system. anybody have the needed equations for this?