JamesB

Thanks for the response. And thank you for the compliment. I think I'm getting there. To be honest it's looking like I'm going to have to get more information regarding the burner itself. I do have one query regarding your suggestion of using a heat exchanger system, if the liquid inside the heat exchanger is water, this would have a maximum temperature, unless pressurised, of 100°C. Would this effectively heat up a body of water enough for evaporation to take place in a reasonable amount of time? increasing the surface area would also speed this up. I have seen similar systems using exhaust gases from burners before however on nowhere near as large amounts of water. But like you said, there could be an issue with corrosion of the piping. I may have to re-think my approach to this. Thanks for the help James

Hi, Thanks for the response. With regards to safety aspects, if there is anything that does stand out as a potential problem please let me know. In terms of temperatures, I am constantly working around far higher temperatures than this so there are already a certain amount of safety protocols in place for anything that I will require. In answer to your questions: I want to evaporate the water. I understand that this can be done at lower temperatures than 100°C but I was using it to try and make things easier, basically I just want to know the calculation so that when I do have all of the information I can work out whether or not it is a feasible option. I'm a chemist/metallurgist but been given an engineering project, as I hope you can imagine I'm a little out of my comfort zone. The point of the evaporator is to separate suspended solids from the water, the steam will just go into the atmosphere, so no replenishment required. As for the chemicals in the water there isn't anything that really raises the boiling point or stop it from evaporating too much. Mainly various compositions of carbonates and hydroxides. I am aware that there are safety concerns here however, as mentioned above, we do have protocols in place for hazardous chemicals. As for the quantity and nature of exhaust gas, currently I do not know. I was hoping that there would be a simple way if you could say the temperature is a constant then you would be able to calculate how long it would take. I know its not 100% efficient but its just a theoretical assumption that I'm looking for. Just a way to progress with the information I currently have. I realise that if you know the kW/h then it's fairly easy to calculate, however I am currently working theoretically so we don't know what the burners will be working at. Hence I was asking that if we can assume a temperature of the pipe we would be able to calculate the time it would take to heat the water to boiling point. It's not the best way to look at it but currently its all I can do. Hope this answers you're queries and thank you for taking the time to help me with this. If it is completely impossible to calculate or I sound like an idiot just tell me as much. It's not really an area I have ever worked in before. Thanks James

Firstly I will apologies if this is in the wrong place, the question I have falls under thermodynamics (maybe) but I'm working on an engineering project. Is there a way to determine the time it would take to boil an amount of water when you only have a temperature? I know you can calculate it if you know the kW/h or BTU used for heating however I do not, I only know the temperature. Let me explain a little better: Lets say you have a metal pipe that constantly has gas flowing through it at 400°C. If this pipe were to go through a tank of water how would you calculate firstly whether you could boil the water, and secondly how long it would take? Basically I am trying to work out whether it is possible to use the heat from an exhaust of a burner as a means for heating an evaporator. The water tank would contain approximately 3500 litres. For ease the water starts off at 10°C and needs to heat to 100°C so the delta T is 90. Thanks for any help. James