Surface Condensers – Part 1





So if you recall a we were discussing regarding condensers and initially I have shown you in our last lecture a power plant condenser which is also known as a surface condenser. And we like to continue with surface condensers through but before doing so what I like to do I like to go back to my previous lecture because the last slide I have told very important I have supplied very important information to you I like to stress about it so if I go back to my previous lecture this was the last flight of the hideous creature to hear you see that last night sing condensacion I will have used so let me tell you a few things regarding this and then again we will go back to the currently how to collect debt let's say this is a vertical flag plate and and she is being taken from people and this side there is it okay to get in contact with you but this will be really thin and then he has made quite a few assumptions and based on that are some since he has determined what could be the transfer number and alsofrom the wall to get back to transfer taking place only contact that is one thing that there is no here at the outer edges of that almost at the stationary condition or we will try to analyse and other otherpeople have died method by which they can take care of these assumptions that the film which forms on the outside of the tube is very thing they need chickens out because all the films are collected and Phil is becoming become thicker and thicker and ultimately as a 6-3 it falls from the bottom of that you and you know that he transferred into conduction so this is liquid feel that is the conduction resistance and that goes on increasing that goes on increasing as we move from the topmost point to the bottlenose point of the tube will be most effective in condensing paper at the topmost point and we’re almost no condensation of paper will take place at the bottom this is important and obviously configuration the element is not in line but standard and these are all important so you are laid out in his jacket so this is very and surface condenser of this complex will be laid out there are different patterns so some of the patterns I have shown here taking from published what is important and what I like you to give some more attention please it is like this steam condensing and emergencynear the temperature in this team has to condense the the steam pressure is sub atmospheric pressure showing part of the circulating fluid loop of a steam power plant the fluid is at a temperature higher than the atmospheric pressure and as part of the loop the pressure is below atmospheric what will happen will take place inside the circulating that means in this team will come to the condenser for condensation it will have here along with it here is a non condensable what will happen again taking some photography from publicity to this is what is the cooling with this green colour is the cooling water red colour is tube wall outside we can see the condensate field but outside their middle ear that means we're quite dense collection of their liberty and obviously then we’d we do not have any paperwork or any vapour molecules which is not going out and content that will increase the pressure of the consent if you think it will reduce the rate of heat transfer is there more it reduces the rate of transfer maurya and their price show is we get to see in summer situation that department capacity of producing that produces the sperm that we have to take this outthis is a typical think this is a typical feature and heat exchanger designer has to take care of this when he is concerned with the design of a condenser for a steam or plant application to let us process here I have shown to very common situation of Steam condenses and these are basically cube layout and hearing see here you see there will be some sort of some sort of greater density of coolant so here we will have more cooling capacity more Webber will be cool and you can get separated from the pack very easy and then it will be taken out by circa extraction it can be taken out from this bottom portion or it can be taken out from the central issue is that we have to help pulling wire explore air extraction point is k so that we are not taking out paper we are only taking out here and also if you’ll be at density will increase so we have to handle this amount of your volume so that is also a secondary point this is one of the very unique design feature of our serviceswe like to help avoid condensation for obvious reasons of very high rate of heat transfer unfortunate that we cannot sustain your boys condensation on commercial tubes which are costly clean environment they can be used and they can suspend rockways condition for a longer. Lot of research is going on but that is not for your Steam condenses voice got invoice condition water feeling or condensing is that is what happenssection of a pot plant contains how many teams are there very large number of 21 tube will wanna let you know that I said too many 20 minuteshas got the maximum capacity of condensing for the next to you I am killing this opportunity because the feeling from the tuba is falling on it and the fee is already ticket here not only that everywhere the TVtransfer navigate from the top view I get from the 2nd to what do I transfer images from the second I will not get from the part you like this this is called face and condensation I mean this is killing condensation in two bundles and this is what happens now flight from this situation one can have if we have this kind of a tube layout which is still unclear but instantly also also we cannot solve the problem if there is lot of people activity and if this film falls with a high velocity then there will be replacing struggling so probably the situation with something different and if there is a positive then it can take care of the liquid inside see if we see again I'll take you back some figure out here so if you see how many teams are there from top to bottom very large number of particular should not be bothered and play number of configuring from the first considering the we will try to see the design of all this kind ofpractical design of a condenser it will be really difficult and I mean it is quite a few activities director procedure which cannot be taken care of but we will try to supply the critical issues points and the physics which goes behind particularly from the heat transfer and continuing of condensationhe has got one more quote him a referral so that is process heat transfer and he could you transfer equipment designs are discussed that he has given in this conservative relationship where the past relationship is that a net cube what will be the transportation and II relationship that it’s like how the average heat transfer coefficient for all that you see there are a number of deals we can so that means the first analysis will be done by the analysis and then for every heat transfer coefficient we had to reduce the transfer efficient and effective is given by the formula shown in the last slide and it can also be from the formula it is sosample of a power of 10 by any number of duis in a particular column this is regarding inundation of the condensate field and which is very important for an we will consider the contents design show will keep it in mind and let us process next next slide I like to give one problem for practice this is very very simple problem we do not have any complexity in it but even then there should be some sort of way there should be some sort of ape practice of what we have learnt so that’s why I have picked up this problem so it says give me send refrigerant 134 a paper that is saturation temperature of 57 degree Celsius is condensing up on a horizontal smooth copper tube of sidewall temperature is maintained constant at 40 degree celsius the outside tube diameter want you to this is our new let’s say some coolant is passing through the tube and and I shoot animals is also another sure we have fun herethis is not sure I know that I’m sure we have fun I really don’t feel we be something like this and this to connect will grow and nothing to analysis has given us the give us the value of Everest film thickness over the surface of a cube surface directly we can use this and then if we go back to our previous the average heat transfer coefficient can be calculated using nascent expression equation sum equation number we have given which is relevant part the equation which I have told you this is from some shows we have taken this data the term of physical property of our 134 a at 47 degrees Celsius are giving this is from some showsbeen facilitating the question related to woodend transfer condition this is just one line so we will substitute this this one and we will get the money transfer coefficient like 162 0.81 per square kilometre of this is simple he has to show how to use this thing which properties are relevant and this is what we have done and probably this kind of problem you have done already in your heat transfer course but before going to a really difficult exam to be like to solve this problem with this way will come to an end of today’s lecture and then we will proceed we have seen condensation on a single tube then we will see you on multiple TV and probably we will go to a heat exchanger particularly the thermal aspects of it some of the points which I have told her very important you don’t listen in condensate condensation particularly when there is a column of tube that is very important because that has got its effect on the entire contents design and particularly relevant for steam condenser design so this is one point I would like you to give an attention. And probably you can also look into literature from the internet to know more about it thank you.