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Lec 21 - Various types of heat exchangers for food process engineering
WEBVTT Kind: captions Language: en
00:00:00.100 [Music] 00:00:21.94000:00:21.950 you 00:00:29.70000:00:29.710 good morning all so today we are going 00:00:32.31000:00:32.320 to discuss about various types of heat 00:00:34.65000:00:34.660 exchanger which are used in the food 00:00:36.96000:00:36.970 process engineering our food process 00:00:39.06000:00:39.070 industries so we go a little 00:00:42.96000:00:42.970 introduction about the heat exchangers 00:00:45.47900:00:45.489 and what our how to design a heat 00:00:47.79000:00:47.800 exchanger and what are all the 00:00:50.70000:00:50.710 applications of heat exchangers in food 00:00:53.10000:00:53.110 process industries and main type of for 00:00:57.29900:00:57.309 heat exchangers we are going to see in 00:00:59.36900:00:59.379 this particular lecture so the heat 00:01:02.25000:01:02.260 exchangers are devices for the exchange 00:01:04.64900:01:04.659 of heat between two fluids separated by 00:01:07.28900:01:07.299 a heat conducting partition so this is 00:01:09.81000:01:09.820 nothing but a wall right two fluids we 00:01:14.64000:01:14.650 have a hot fluid as well as cold fluid 00:01:17.16000:01:17.170 so mostly cold fluid is here is your a 00:01:20.13000:01:20.140 liquid flow food particle sometimes with 00:01:23.31000:01:23.320 the particulate solids heat exchangers 00:01:26.19000:01:26.200 are extensively used in the food 00:01:28.05000:01:28.060 industry for heating which is nothing 00:01:30.48000:01:30.490 but pass tracer and cooling chilled 00:01:33.69000:01:33.700 water generators and heat induced phase 00:01:36.72000:01:36.730 change so which is nothing but a 00:01:38.34000:01:38.350 freezing and evaporation so this 00:01:40.44000:01:40.450 evaporation we have seen in the membrane 00:01:42.42000:01:42.430 separation as well to concentrate the 00:01:44.58000:01:44.590 food material right so then each one of 00:01:48.33000:01:48.340 the fluids may be confined or unconfined 00:01:51.18000:01:51.190 stagnant or flowing so depends upon the 00:01:54.21000:01:54.220 heat exchanger we use so each one of the 00:01:57.39000:01:57.400 two fluids may be confined or unconfined 00:01:59.79000:01:59.800 stagnant or flowing the partition is a 00:02:02.88000:02:02.890 heat conducting solid Volusia Li made of 00:02:05.31000:02:05.320 metal to give high thermal conductivity 00:02:07.52000:02:07.530 the design of a heat exchanger usually 00:02:10.38000:02:10.390 involves two main domains namely thermal 00:02:12.80900:02:12.819 analysis and hydraulic calculations 00:02:15.14900:02:15.159 because the heat exchanger the food is 00:02:17.39900:02:17.409 liquid food right so if you remember in 00:02:19.74000:02:19.750 our a septic processing calculations I 00:02:22.08000:02:22.090 told the same thing because in 00:02:24.74000:02:24.750 continuous thermal processing so we need 00:02:27.80900:02:27.819 to take care of the hydraulic 00:02:29.75900:02:29.769 calculations as well as the thermal 00:02:31.44000:02:31.450 analysis heat transfer as well as fluid 00:02:33.53900:02:33.549 flow so here is one example so this is a 00:02:38.91000:02:38.920 solid wall these two are solid walls 00:02:41.25000:02:41.260 right the heat is given 00:02:43.36000:02:43.370 here in the solid wall so their 00:02:45.88000:02:45.890 temperature here ta in the outside of 00:02:49.78000:02:49.790 the wall 00:02:50.38000:02:50.390 and T be in the other side of the wall 00:02:52.54000:02:52.550 and the wall temperature is t1 and this 00:02:56.08000:02:56.090 side it is t2 and the h1 is nothing but 00:02:59.19900:02:59.209 a heat transfer coefficient H 2 is a 00:03:01.66000:03:01.670 heat transfer coefficient in the other 00:03:03.52000:03:03.530 side right so this is the ambient maybe 00:03:06.46000:03:06.470 we can consider so this is also ambient 00:03:12.80900:03:12.819 or you can consider here maybe another 00:03:18.22000:03:18.230 Florida's there right so now if we want 00:03:22.66000:03:22.670 to write Q the heat balance Q is nothing 00:03:26.50000:03:26.510 but a ta minus TB right so flux which is 00:03:33.78900:03:33.799 nothing but a q upon a write Q upon a is 00:03:36.64000:03:36.650 nothing but he turns fur rate upon area 00:03:39.46000:03:39.470 so heat transfer rate is nothing but in 00:03:41.83000:03:41.840 watts and area is in meter square so 00:03:45.55000:03:45.560 this part is nothing but joules per 00:03:47.31900:03:47.329 second so that means heat transfer rate 00:03:49.66000:03:49.670 per meter square which is nothing but a 00:03:52.00000:03:52.010 heat flux heat flux can be written as a 00:03:55.05000:03:55.060 thermal gradient because in heat 00:03:57.43000:03:57.440 transfer it is a thermal gradient any 00:03:59.77000:03:59.780 flux can be written as a gradient apart 00:04:02.83000:04:02.840 resistance okay so in heat transfer it 00:04:06.25000:04:06.260 is a thermal gradient the R we are going 00:04:08.77000:04:08.780 to write so R if you see so this is the 00:04:11.38000:04:11.390 H 1 H 1 is nothing but ER 00:04:13.75000:04:13.760 he transfer coefficient right convective 00:04:17.28900:04:17.299 heat transfer coefficient and this is 00:04:19.75000:04:19.760 nothing but a solid solid material for 00:04:22.15000:04:22.160 example this is the wall of the heat 00:04:25.30000:04:25.310 exchanger right so this is the wall of 00:04:27.52000:04:27.530 the heat exchanger this side one fluid 00:04:30.07000:04:30.080 resides the other side of the wall 00:04:32.46900:04:32.479 another fluid reside so instead of 00:04:34.60000:04:34.610 ambient you can take an example of heat 00:04:37.87000:04:37.880 exchanger itself right so this is the 00:04:39.96900:04:39.979 heat exchanger wall so one fluid recites 00:04:42.64000:04:42.650 this side another fluid recites that 00:04:44.26000:04:44.270 side so the H one is the heat transfer 00:04:46.90000:04:46.910 coefficient of this particular fluid da 00:04:49.00000:04:49.010 and H two is the heat transfer 00:04:52.27000:04:52.280 coefficient of fluid B and that 00:04:54.37000:04:54.380 temperature T one is at the wall 00:04:57.22000:04:57.230 near the fluidy a site t2 is the 00:04:59.14000:04:59.150 temperature in the wall at near the 00:05:01.09000:05:01.100 fluid B side right so that TB is a 00:05:05.64000:05:05.650 temperature of the fluid B and T a is 00:05:08.95000:05:08.960 the temperature of fluid a so I have 00:05:11.80000:05:11.810 basically three resistance one on the 00:05:14.02000:05:14.030 fluid a side another on the wall and 00:05:16.51000:05:16.520 another on the fluid B side right so I 00:05:19.42000:05:19.430 can combine them 1 upon H 1 because 00:05:22.09000:05:22.100 there hates is nothing but a heat 00:05:23.68000:05:23.690 transfer coefficient resistances one 00:05:26.08000:05:26.090 upon conductance so then your conductive 00:05:29.08000:05:29.090 resistance is nothing but X upon K X is 00:05:32.29000:05:32.300 nothing but a thickness of the wall okay 00:05:36.55000:05:36.560 so that I am taking as a X so X upon k 00:05:40.06000:05:40.070 plus 1 upon H 2 right so this is the 00:05:43.39000:05:43.400 resistance right so here the T is in 00:05:47.44000:05:47.450 Kelvin right so the 1 upon H is watt per 00:05:52.12000:05:52.130 meter square Kelvin so your excess meter 00:05:56.17000:05:56.180 K is watt per meter Kelvin so this is 1 00:06:01.78000:06:01.790 upon watt per meter square Kelvin so 00:06:05.32000:06:05.330 which is nothing but K upon 1 upon if 00:06:09.73000:06:09.740 the meter comes here it is 1 upon meter 00:06:12.40000:06:12.410 so this also 1 upon watt per meter 00:06:14.80000:06:14.810 square 1 upon watt per meter square 00:06:18.52000:06:18.530 Kelvin so this goes about so which is 00:06:22.87000:06:22.880 nothing but KK get cancelled so this 00:06:25.18000:06:25.190 also will become watt per meter square 00:06:27.76000:06:27.770 what per meter square you know 00:06:29.47000:06:29.480 disconcert so I can write my Q as a a TB 00:06:35.08000:06:35.090 minus T ta minus TB 00:06:46.29000:06:46.300 / one upon you so this one upon you is 00:06:50.86000:06:50.870 nothing but 1 upon H 1 + X upon K so 00:06:55.36000:06:55.370 this is a conductive resistance this is 00:06:57.28000:06:57.290 convective resistance plus 1 upon H 2 00:07:00.22000:07:00.230 this is also convective resistance so if 00:07:02.56000:07:02.570 you write Q is equal to you yet ta minus 00:07:05.77000:07:05.780 TB is nothing but del T so U is nothing 00:07:08.92000:07:08.930 but overall heat transfer coefficient AC 00:07:12.25000:07:12.260 area del T is nothing but temperature 00:07:14.74000:07:14.750 difference between the fluids T ADB and 00:07:17.26000:07:17.270 Q is nothing but heat transfer rate so 00:07:19.84000:07:19.850 if you remember we have done in the past 00:07:23.17000:07:23.180 recession play a type heat exchanger 00:07:25.00000:07:25.010 problem we have also calculated number 00:07:27.31000:07:27.320 of plates required for the heating so if 00:07:31.06000:07:31.070 you remember we have taken the you write 00:07:33.85000:07:33.860 the milk side heat transfer coefficient 00:07:36.10000:07:36.110 in heating cooling as well as the 00:07:38.92000:07:38.930 regeneration there we have taken around 00:07:41.17000:07:41.180 approximately thousand watt per meter 00:07:44.35000:07:44.360 squared Kelvin so if your fluid a is 00:07:47.11000:07:47.120 liquid and fluid B is liquid in the 00:07:49.87000:07:49.880 plate heat exchanger type you are use 00:07:52.12000:07:52.130 around thousand to three thousand watt 00:07:54.94000:07:54.950 per meter squared Kelvin so that's what 00:07:57.64000:07:57.650 it is given so based on the fluid for 00:08:00.94000:08:00.950 example if it is a gas gas in tubular 00:08:03.28000:08:03.290 heat exchanger so you were heat transfer 00:08:05.92000:08:05.930 coefficient Phi 250 watt per meter 00:08:08.29000:08:08.300 squared Kelvin so if you remember the 00:08:11.29000:08:11.300 same pasteurization lecture I also told 00:08:14.98000:08:14.990 in the past tracer or sterilizer you 00:08:18.22000:08:18.230 should not keep the AR packets because 00:08:20.59000:08:20.600 AR is a very low conductive medium so 00:08:24.13000:08:24.140 you can see from here the liquid if you 00:08:27.19000:08:27.200 have a fluid is a liquid fluid B as a 00:08:29.65000:08:29.660 liquid you are overall heat transfer 00:08:31.27000:08:31.280 coefficient is thousand around thousand 00:08:33.76000:08:33.770 watt per meter square so if you have a 00:08:35.80000:08:35.810 gaseous heat exchanger so your overall 00:08:38.46900:08:38.479 coefficient is 5 250 watt per meter 00:08:40.71900:08:40.729 squared Kelvin so if you have er packets 00:08:43.54000:08:43.550 inside the sterilizer or the pass racing 00:08:46.93000:08:46.940 unit so that will lead to high 00:08:49.66000:08:49.670 temperature difference between the food 00:08:52.00000:08:52.010 material so that leads to contamination 00:08:54.70000:08:54.710 so this is the reason we need to avoid 00:08:56.92000:08:56.930 yeah 00:08:57.94000:08:57.950 in sterilizing operation okay so the 00:09:01.32000:09:01.330 introduction in continuous heat 00:09:03.52000:09:03.530 exchangers both the fluids are in 00:09:05.62000:09:05.630 movement right so mostly the heat 00:09:08.47000:09:08.480 exchanger we use for continuous flow in 00:09:11.47000:09:11.480 continuous a heat exchanger both fluids 00:09:14.05000:09:14.060 are in moment there are three main types 00:09:16.33000:09:16.340 of flow patterns one is parallel counter 00:09:19.27000:09:19.280 current and cross flow so one example 00:09:22.06000:09:22.070 would be this one so this is a counter 00:09:25.54000:09:25.550 current counter current your heart fluid 00:09:32.74000:09:32.750 is coming in and going this side and 00:09:36.85000:09:36.860 your cold fluid is coming here so and 00:09:41.28000:09:41.290 leaving this side of the heat exchanger 00:09:46.87000:09:46.880 so this is the counter current 00:09:48.16000:09:48.170 co-current means your fluid hot fluid as 00:09:52.47000:09:52.480 well as cold fluid hot fluid hot out hot 00:09:57.73000:09:57.740 in so you are cold in and cold out it 00:10:07.09000:10:07.100 cross flow is nothing but so you are 00:10:10.29000:10:10.300 heart Florida and they were hot fluid 00:10:17.65000:10:17.660 out 00:10:22.61000:10:22.620 so this is inside the tube okay through 00:10:25.73000:10:25.740 your cold fluid will be perpendicular to 00:10:29.38900:10:29.399 a hard fluid direction so this is 00:10:35.72000:10:35.730 nothing but your cross flow okay so this 00:10:41.78000:10:41.790 is counter current flow this is 00:10:43.06900:10:43.079 co-current flow parallel and counter 00:10:45.31900:10:45.329 flow are most common in liquid liquid as 00:10:48.13900:10:48.149 well as liquid to condensing vapor heat 00:10:50.80900:10:50.819 exchange 00:10:51.53000:10:51.540 so this condensing vapor is nothing but 00:10:53.74900:10:53.759 you use the phase change heat to heat 00:10:57.49900:10:57.509 the liquid for example if you take 00:11:00.34000:11:00.350 heating the food material most of the 00:11:03.19900:11:03.209 time we have seen heating medium as a 00:11:05.42000:11:05.430 steam right so this is cold in cold the 00:11:09.31900:11:09.329 fluid in and a cold fluid out so if you 00:11:14.03000:11:14.040 see in the latent heat exchange so there 00:11:16.85000:11:16.860 won't be any temperature difference so 00:11:18.73900:11:18.749 this is a steam temperature hearten and 00:11:23.26900:11:23.279 hot out okay so there won't be any 00:11:27.42900:11:27.439 temperature difference in the steam so 00:11:30.17000:11:30.180 it is a parallel as well as counter 00:11:33.19900:11:33.209 current flow or most common and liquid 00:11:35.44900:11:35.459 liquid or liquid to condensing vapor 00:11:37.73000:11:37.740 heat exchange right and cash flow 00:11:40.30900:11:40.319 exchange is particularly common for 00:11:42.23000:11:42.240 heating or cooling the yeah 00:11:44.21000:11:44.220 so that is gas gas heat exchanger we 00:11:46.36900:11:46.379 have seen right so their grass flow is 00:11:48.41000:11:48.420 mainly used as a result of flow the 00:11:50.96000:11:50.970 temperature of each fluid and therefore 00:11:53.17900:11:53.189 the temperature drop for heat transfer 00:11:55.40000:11:55.410 may change from one point to other point 00:11:58.18900:11:58.199 in the exchanger so this is where the 00:12:00.88900:12:00.899 concept of log mean temperature 00:12:02.78000:12:02.790 difference has come so L M TD so if you 00:12:06.86000:12:06.870 remember in all the calculations we have 00:12:09.98000:12:09.990 used Q is equal to UA Delta young all 00:12:14.26900:12:14.279 right so this is nothing but log mean 00:12:16.73000:12:16.740 temperature difference 00:12:27.32900:12:27.339 so what does it mean so it means 00:12:44.69000:12:44.700 so I'm putting this since a wall so here 00:12:48.26000:12:48.270 is your hard floor den so here is your 00:12:55.37000:12:55.380 hard floor doubt so cold fluid in I am 00:13:02.66000:13:02.670 taking co-current flow and a cold flow 00:13:05.66000:13:05.670 it out okay 00:13:11.84000:13:11.850 so if you make it in terms of X versus 00:13:16.76000:13:16.770 distance versus temperature so that thi 00:13:25.36000:13:25.370 th i th walk th out so this is y n so 00:13:32.78000:13:32.790 the this is TC in and TC out okay so if 00:13:40.61000:13:40.620 I take a particular area so this would 00:13:47.84000:13:47.850 give me t touch in and th out so the 00:13:55.37000:13:55.380 same way for this particular area 00:14:07.01900:14:07.029 TC in and TC out okay so this D had 00:14:15.17900:14:15.189 chain minus TC in we call it as a del T 00:14:18.62900:14:18.639 PI so this we call it as a del T me okay 00:14:24.09000:14:24.100 so then finally the derivation of LM TD 00:14:27.36000:14:27.370 I'm not going to do because that is not 00:14:29.61000:14:29.620 in the syllabus of this particular 00:14:32.51900:14:32.529 course but I would like to tell you that 00:14:34.74000:14:34.750 if you really wanted to know in depth of 00:14:37.88900:14:37.899 why we need to calculate logarithmic 00:14:40.23000:14:40.240 mean temperature difference how to 00:14:41.75900:14:41.769 derive that you may refer some of the 00:14:44.79000:14:44.800 books given in the reference okay so the 00:14:48.42000:14:48.430 the final the del T M how do we write 00:14:51.66000:14:51.670 this which is nothing but del T I minus 00:14:55.35000:14:55.360 del te so this is Inlet this is exit I 00:14:59.17900:14:59.189 divided by lon of del T divided by Del T 00:15:04.92000:15:04.930 so why we are taking mean temperature 00:15:07.35000:15:07.360 difference because the throughout that 00:15:10.19900:15:10.209 distance my delta T is varying so I 00:15:13.47000:15:13.480 cannot take one particular delta T so if 00:15:16.35000:15:16.360 you see here so this is the delta T here 00:15:19.57900:15:19.589 so it is there delta T here okay so it 00:15:23.34000:15:23.350 is varying along the length of the heat 00:15:25.19900:15:25.209 exchanger that is the way we take mean 00:15:27.72000:15:27.730 temperature difference logarithmic mean 00:15:29.54900:15:29.559 temperature difference and also remember 00:15:32.57900:15:32.589 here I have taken use constant along the 00:15:36.56900:15:36.579 length because though my temperature is 00:15:38.63900:15:38.649 varying my overall heat transfer 00:15:40.35000:15:40.360 coefficient is constant so from this I 00:15:43.35000:15:43.360 will calculate the log mean temperature 00:15:45.48000:15:45.490 difference then substitute in the Q 00:15:47.67000:15:47.680 formula which is nothing but you ei del 00:15:49.94900:15:49.959 T here you can substitute u ru and Q you 00:15:54.09000:15:54.100 will be able to know Q's nothing but for 00:15:57.11000:15:57.120 hard fluid mass flow rate of hot fluid 00:16:00.26900:16:00.279 CP of hot fluid and del T del T in the 00:16:05.36900:16:05.379 sense T hatch in minus T hatch out okay 00:16:10.94900:16:10.959 so the if you write for cold fluid it is 00:16:13.43900:16:13.449 a mass flow rate of cold fluid CP of 00:16:16.91900:16:16.929 cold fluid this is TC in - 00:16:19.74000:16:19.750 TC out okay so remember one heart fluid 00:16:26.22000:16:26.230 loses heat losses heat and cold fluid 00:16:39.48000:16:39.490 gains the heat so this is the way we 00:16:49.68000:16:49.690 calculate and design the heat exchanger 00:16:51.96000:16:51.970 right so if I want to know how much heat 00:16:54.63000:16:54.640 transfer area is needed to heat my fluid 00:16:59.67000:16:59.680 the food or liquid food so I will get to 00:17:03.60000:17:03.610 know from Q by u del T ya so the Delta 00:17:08.88000:17:08.890 if I know Inlet outlet temperature if I 00:17:11.57900:17:11.589 know flow configuration whether it is a 00:17:13.53000:17:13.540 counter flow or cross flow or co-current 00:17:16.07900:17:16.089 flow then I'll be able to calculate my 00:17:18.44900:17:18.459 del T I del te and from there I will 00:17:21.12000:17:21.130 calculate the log mean temperature and 00:17:24.54000:17:24.550 from the log mean temperature I will be 00:17:26.85000:17:26.860 able to calculate the area provided u is 00:17:30.99000:17:31.000 given and Q I will be able to calculate 00:17:33.39000:17:33.400 from mass rate of the hot fluid this is 00:17:36.00000:17:36.010 mass rate which is nothing but in kg per 00:17:38.76000:17:38.770 second or hour so this is kilo joules 00:17:41.58000:17:41.590 per kg Kelvin so this is in Kelvin 00:17:45.36000:17:45.370 so this Kelvin Kelvin gets canceled kilo 00:17:47.76000:17:47.770 joules per hour so you if you convert 00:17:50.52000:17:50.530 into joules kilo joules per second so 00:17:54.57000:17:54.580 that is nothing but kilo but so what I 00:17:57.57000:17:57.580 told you is here this is also in butts 00:18:00.78000:18:00.790 right so unit you can calculate the Q 00:18:04.20000:18:04.210 and substitute in the J formula so that 00:18:06.87000:18:06.880 is the way you design the heat transfer 00:18:09.09000:18:09.100 area for liquid to food to be heated in 00:18:12.54000:18:12.550 the heat exchanger so then intro about 00:18:16.62000:18:16.630 the heat exchanger why we need to study 00:18:18.81000:18:18.820 and improvement in quality is one of the 00:18:21.81000:18:21.820 main driving forces behind the 00:18:23.82000:18:23.830 development of continuous heat processes 00:18:26.40000:18:26.410 so the liquid semi-liquid products such 00:18:29.55000:18:29.560 as milk juices and sauces 00:18:32.50000:18:32.510 suffered from over processing in 00:18:34.84000:18:34.850 traditional low-temperature long time of 00:18:38.11000:18:38.120 an in container or batch processing 00:18:40.81000:18:40.820 batch processing in one of the lectures 00:18:43.06000:18:43.070 also we have discussed an Armas Li so I 00:18:45.61000:18:45.620 just to put it and forget it for example 00:18:47.65000:18:47.660 if you see the temperature for the 00:18:51.34000:18:51.350 pasteurization 63 degree centigrade 00:18:54.31000:18:54.320 about 30 minutes so this causes the 00:18:57.13000:18:57.140 lower processing so due to which the 00:19:00.28000:19:00.290 continuous process came into existence 00:19:02.95000:19:02.960 so caramelized two flavors poor color 00:19:05.77000:19:05.780 retention and a lack of a reproducible 00:19:08.91900:19:08.929 product where all the problems 00:19:10.65900:19:10.669 associated with the products processed 00:19:13.45000:19:13.460 by batch method so to overcome these 00:19:16.50000:19:16.510 disadvantages then to keep product 00:19:20.16900:19:20.179 safety in mind the continuous processing 00:19:23.40900:19:23.419 approaches were developed the 00:19:26.04900:19:26.059 achievement of safe products by a 00:19:28.03000:19:28.040 thermal processing is based upon the 00:19:30.19000:19:30.200 theory behind the destruction of 00:19:31.98000:19:31.990 microorganisms so why we are thermal 00:19:34.51000:19:34.520 processing it the for the reason for 00:19:37.02000:19:37.030 destruction of microorganisms the 00:19:39.82000:19:39.830 products must be heated to a set 00:19:42.34000:19:42.350 temperature for a set time in order to 00:19:44.77000:19:44.780 achieve a commercially sterile product 00:19:47.23000:19:47.240 in continuous heat processing also 00:19:49.90000:19:49.910 called continuous flow processing the 00:19:52.39000:19:52.400 product is thermally processed before 00:19:54.52000:19:54.530 being placed into an appropriate 00:19:56.79900:19:56.809 container on a continuous basis through 00:19:59.95000:19:59.960 a heat exchanging plant so the main part 00:20:02.59000:20:02.600 of the continuous thermal processing is 00:20:05.35000:20:05.360 nothing but a heat exchanger okay so the 00:20:11.79900:20:11.809 heat exchanger paratus will be used to 00:20:13.84000:20:13.850 for both heating as well as cooling 00:20:16.20000:20:16.210 cooling phase of the process this we 00:20:19.33000:20:19.340 discussed in our earlier lectures itself 00:20:21.82000:20:21.830 so heating as well as cooling and in few 00:20:24.73000:20:24.740 see in the aseptic process regeneration 00:20:27.07000:20:27.080 also in between heating regeneration and 00:20:29.95000:20:29.960 cooling in continuous system the foots 00:20:33.07000:20:33.080 under consideration are liquid or 00:20:35.32000:20:35.330 semi-liquid products which may be pumped 00:20:38.44000:20:38.450 through a system heated and cooled while 00:20:41.23000:20:41.240 continuously flowing down the process 00:20:43.29900:20:43.309 line a wide range of prod 00:20:45.67000:20:45.680 so I processed by this method that means 00:20:47.86000:20:47.870 the continuous flow process either a 00:20:50.02000:20:50.030 main process to achieve a safe product 00:20:52.48000:20:52.490 the main process itself a heat 00:20:55.00000:20:55.010 exchanging process which is nothing but 00:20:56.98000:20:56.990 ultra heat treated or ultra high 00:20:59.08000:20:59.090 temperature are a step with enough 00:21:01.81000:21:01.820 further processing the heat exchanger 00:21:03.94000:21:03.950 may be used as an intermediate step to 00:21:06.76000:21:06.770 heat the fluid or the main process 00:21:09.49000:21:09.500 itself a heat exchanging process which 00:21:11.68000:21:11.690 is happening in the ultra high 00:21:13.33000:21:13.340 temperature or even aseptic processing 00:21:15.61000:21:15.620 the three main types of process are 00:21:18.43000:21:18.440 suitable for continuous flow processing 00:21:20.74000:21:20.750 or a septic systems which is high and 00:21:23.41000:21:23.420 low acid foot and heart fill systems 00:21:25.98000:21:25.990 pasteurization process so everything 00:21:28.66000:21:28.670 comes under this continuous flow process 00:21:31.27000:21:31.280 category aseptically pact products or 00:21:34.75000:21:34.760 process two temperatures that will 00:21:36.73000:21:36.740 render the product commercially sterile 00:21:39.34000:21:39.350 so aseptic processing we have already 00:21:41.56000:21:41.570 seen in maybe three lectures I guess so 00:21:46.30000:21:46.310 then heating applications so this also 00:21:48.94000:21:48.950 we have discussed if it is a high acid 00:21:51.28000:21:51.290 products such as juice can be processed 00:21:54.61000:21:54.620 at pasteurization temperature to destroy 00:21:56.83000:21:56.840 the microorganism that can cost the 00:21:59.14000:21:59.150 spoilage of the product there are then 00:22:01.42000:22:01.430 rapidly cool to reduce the loss of 00:22:03.88000:22:03.890 volatiles within the product also to 00:22:06.40000:22:06.410 reduce the contamination of thermo 00:22:09.28000:22:09.290 philic bacterias right because when you 00:22:11.98000:22:11.990 slowly cooling there may be a chance for 00:22:14.86000:22:14.870 the Bri contamination so the cooling is 00:22:17.65000:22:17.660 done very rapidly and filled into a 00:22:21.00000:22:21.010 pre-sterilized pack under sterile 00:22:23.35000:22:23.360 conditions so hot acid products we do 00:22:25.93000:22:25.940 pasteurization and a packet under 00:22:28.27000:22:28.280 sterile conditions in a sterilized 00:22:30.34000:22:30.350 packaging the low acid products which 00:22:33.01000:22:33.020 undergo same principle however the 00:22:35.02000:22:35.030 temperature employed are much higher to 00:22:37.45000:22:37.460 and should no survival of the pathogenic 00:22:40.27000:22:40.280 bacteria so that's why we go for a 00:22:42.61000:22:42.620 sterilization the temperature applied 00:22:44.95000:22:44.960 here at 125 to 145 degree so allowing 00:22:48.61000:22:48.620 for much shorter holding times and 00:22:50.89000:22:50.900 promoting a higher quality product the 00:22:53.86000:22:53.870 continuous flow processing system can 00:22:55.90000:22:55.910 also be used in a heartful processes for 00:22:59.04900:22:59.059 high acid products again heart fill 00:23:00.94000:23:00.950 processes r5 high acid products that 00:23:03.78900:23:03.799 would otherwise lose product quality 00:23:05.86000:23:05.870 through slow cooling methods and high 00:23:10.62900:23:10.639 acid choices again high acid food comes 00:23:13.57000:23:13.580 under pasteurization category they are 00:23:15.78900:23:15.799 filling directly into suitable 00:23:17.59000:23:17.600 containers using the heat of the product 00:23:20.28900:23:20.299 to decontaminate the packaging so 00:23:23.04900:23:23.059 sometimes this also tried so this method 00:23:25.60000:23:25.610 is this method allows a much quicker 00:23:28.29900:23:28.309 throughput than a typical batch process 00:23:31.60000:23:31.610 would offer the high acid cetain high 00:23:34.41900:23:34.429 acid foots path traced and filled in the 00:23:37.77900:23:37.789 normal containers not in a sterile 00:23:39.94000:23:39.950 containers so the product heat itself 00:23:42.39900:23:42.409 further decontaminate the packaging so 00:23:44.98000:23:44.990 this also another heating applications 00:23:46.98900:23:46.999 where heat exchanging systems are used 00:23:48.99900:23:49.009 and pasteurization of low acid products 00:23:51.85000:23:51.860 that will then be cooled and held under 00:23:54.15900:23:54.169 chill the conditions so this is where we 00:23:56.20000:23:56.210 don't so we need to refrigerate them 00:23:58.98900:23:58.999 even low acid products so pasteurized 00:24:01.35900:24:01.369 milk juices soups everything comes under 00:24:04.11900:24:04.129 this category this processing step 00:24:06.51900:24:06.529 extends the shelf life and ensures the 00:24:09.46000:24:09.470 safe product the product must be chilled 00:24:12.27900:24:12.289 to maintain its safety and quality 00:24:14.20000:24:14.210 throughout the shelf life shelve lives 00:24:16.57000:24:16.580 up to ten days can be achieved for some 00:24:19.21000:24:19.220 products so these are all some of the 00:24:21.24900:24:21.259 heating up applications furnace high 00:24:23.16900:24:23.179 acid products which are pasteurized and 00:24:26.00900:24:26.019 part-owner sterilized to packaging under 00:24:28.60000:24:28.610 sterile condition low acid products 00:24:30.66900:24:30.679 which are to be sterilized to kill the 00:24:33.07000:24:33.080 pathogenic bacteria and heartful 00:24:35.73900:24:35.749 processes where high acid products are 00:24:38.10900:24:38.119 processed and these high acid products 00:24:41.95000:24:41.960 are processed and filled in the 00:24:43.69000:24:43.700 packaging so that temperature of the 00:24:45.97000:24:45.980 products itself will take care of the 00:24:48.21000:24:48.220 decontamination of the packaging system 00:24:50.71000:24:50.720 then further pasteurization of low acid 00:24:53.79900:24:53.809 products here we did sterilization so if 00:24:56.61900:24:56.629 you do pasteurization that has to be 00:24:58.53900:24:58.549 chilled to extend the further shelf life 00:25:01.88900:25:01.899 okay so although heating vessels are 00:25:04.89900:25:04.909 cooking kettles by definition heat 00:25:07.50900:25:07.519 exchanges so whatever we use in 00:25:09.51900:25:09.529 day-to-day life those also called as a 00:25:11.88900:25:11.899 heat 00:25:12.40000:25:12.410 changer because the heat exchanger is 00:25:14.32000:25:14.330 one which exceeds the heat right through 00:25:17.11000:25:17.120 a solid one they themself cooking 00:25:19.42000:25:19.430 kettles themself as a heat exchanger 00:25:21.79000:25:21.800 even one of the lecture I mentioned 00:25:23.52000:25:23.530 whatever we do in normal day-to-day 00:25:26.14000:25:26.150 process which is nothing but a 00:25:28.12000:25:28.130 pasteurization of milk so whenever we 00:25:30.37000:25:30.380 are heating the milk we are doing 00:25:32.11000:25:32.120 pasteurization but that is not the case 00:25:34.36000:25:34.370 with the industry they have to handle 00:25:36.73000:25:36.740 the large volume and they have supposed 00:25:38.74000:25:38.750 to store and distribute for further use 00:25:41.44000:25:41.450 so in that case GMP regulations were to 00:25:44.20000:25:44.210 be followed right good manufacturing 00:25:46.12000:25:46.130 practices to be followed here also the 00:25:50.32000:25:50.330 heat exchangers cooking kettles also by 00:25:53.11000:25:53.120 definition heat exchangers but the only 00:25:56.50000:25:56.510 continuous inflow heat exchangers which 00:25:59.17000:25:59.180 are used in the food processing industry 00:26:00.96000:26:00.970 which we will be discussed in this 00:26:03.76000:26:03.770 lecture because of strict sanitary 00:26:06.49000:26:06.500 requirements right so only a few of the 00:26:09.70000:26:09.710 many heat exchanger types utilized in 00:26:12.19000:26:12.200 the process industry are suitable for 00:26:14.44000:26:14.450 food applications so the same thing I'll 00:26:17.95000:26:17.960 be telling in the dryers as well so we 00:26:21.82000:26:21.830 are also going to have a lectures on dry 00:26:23.86000:26:23.870 as various andreas used in the food 00:26:26.08000:26:26.090 processing industry there there are lot 00:26:28.60000:26:28.610 of dryers are there and even normal 00:26:30.97000:26:30.980 chemical industry also uses various 00:26:33.16000:26:33.170 dryers but these dryers which are used 00:26:37.51000:26:37.520 in food industry should be hygienic 00:26:39.70000:26:39.710 right the dehydration plant should be 00:26:41.92000:26:41.930 contamination free for for the dryers to 00:26:46.18000:26:46.190 be used in the food industry the same 00:26:48.10000:26:48.110 thing here even though there are lot 00:26:50.11000:26:50.120 many varieties of heat exchangers are 00:26:52.30000:26:52.310 available in the processing industries 00:26:54.22000:26:54.230 but food processing industry strictly 00:26:56.83000:26:56.840 follows the sanitary requirements so 00:26:59.23000:26:59.240 because of which very few types of heat 00:27:01.75000:27:01.760 exchangers are used 00:27:03.42000:27:03.430 the first one is tubular heat exchanger 00:27:06.34000:27:06.350 the simplest representative of this 00:27:08.74000:27:08.750 group consists of a pair of 00:27:10.59000:27:10.600 concentrating tubes for ease of cleaning 00:27:13.81000:27:13.820 the food product usually flows in the 00:27:16.39000:27:16.400 inner tube and the heating or cooling 00:27:18.43000:27:18.440 medium in the outer annular space there 00:27:21.52000:27:21.530 variation of this type is the triple 00:27:23.86000:27:23.870 tube right so which 00:27:26.01900:27:26.029 has three tubes as a concentric tube in 00:27:29.16900:27:29.179 the middle tube your product would be 00:27:31.53900:27:31.549 flowing the other two inner and outer 00:27:34.18000:27:34.190 tube your heating and cooling medium if 00:27:36.31000:27:36.320 it is a heating process it is a heating 00:27:38.85900:27:38.869 medium if it is a cooling process it is 00:27:40.69000:27:40.700 a cooling medium the product is fed into 00:27:42.90900:27:42.919 the middle tube and the heating or 00:27:45.12900:27:45.139 cooling medium to the inner and outer 00:27:47.04900:27:47.059 tube which provides the heat transfer 00:27:49.33000:27:49.340 areas on both side of the middle tube so 00:27:51.96900:27:51.979 if you have a tube in concentric double 00:27:56.56000:27:56.570 pipe heat exchanger so you will have the 00:27:59.82900:27:59.839 hard fluid flowing in here so if you 00:28:03.48900:28:03.499 have one more tube 00:28:05.13900:28:05.149 so probably we will see in the here the 00:28:07.57000:28:07.580 water Steuben tube as well as tube in 00:28:10.14900:28:10.159 tube in tube heat exchanger first we 00:28:12.45900:28:12.469 will see the theory so the product is 00:28:14.79900:28:14.809 fed to the middle tube and that heating 00:28:16.98900:28:16.999 and cooling medium to the inner and 00:28:18.72900:28:18.739 outer tube thus providing heat transfer 00:28:20.95000:28:20.960 areas on both side of the middle tube 00:28:23.13900:28:23.149 the calculation of overall heat transfer 00:28:25.14900:28:25.159 coefficient for this type of equipment 00:28:27.45900:28:27.469 is more complex so whatever I told here 00:28:30.19000:28:30.200 so here fluid is flowing other side of 00:28:32.68000:28:32.690 the wall one heat exchanger wall is 00:28:34.83900:28:34.849 there one fluid is flowing this side 00:28:36.51900:28:36.529 another fluid is flowing this side so 00:28:38.49900:28:38.509 that is the way we calculated the 00:28:39.99900:28:40.009 overall heat transfer coefficient but if 00:28:42.12900:28:42.139 you have a three tubes then you need to 00:28:44.44000:28:44.450 further calculate the heat transfer 00:28:46.26900:28:46.279 coefficient that is not that easy or 00:28:48.94000:28:48.950 straightforward method to calculate the 00:28:51.20900:28:51.219 overall heat transfer coefficient for 00:28:53.46900:28:53.479 the triple tube heat exchanger than the 00:28:56.58900:28:56.599 double tube heat exchanger so the next 00:28:59.37900:28:59.389 one is shell and tube the tubular heat 00:29:01.59900:29:01.609 exchanger consists of a bundles of 00:29:03.87900:29:03.889 parallel tubes inside a larger 00:29:06.21900:29:06.229 cylindrical jacket again the product is 00:29:09.07000:29:09.080 fed into the tube side so in your type 00:29:11.88900:29:11.899 of tubular exchanger known as a Joule 00:29:14.32000:29:14.330 effect heater the tube wall is 00:29:16.69000:29:16.700 electrically heated so it is not to be 00:29:19.38900:29:19.399 necessarily the cold fluid will be 00:29:21.54900:29:21.559 heated through the hot fluid so here in 00:29:25.38900:29:25.399 the certain type of tubular exchanger 00:29:28.18000:29:28.190 which is called as a Joule effect heater 00:29:30.51900:29:30.529 the tube wall is founded with the 00:29:32.28900:29:32.299 electrical coils they can be heated 00:29:35.22900:29:35.239 electrically as well the tubular heat 00:29:37.89900:29:37.909 exchangers are particularly so 00:29:39.73000:29:39.740 trouble for heating or cooling highly 00:29:41.98000:29:41.990 viscous products we're relatively high 00:29:44.89000:29:44.900 pressures must be applied or therefore 00:29:47.74000:29:47.750 heat relized foreign bulk inflow 00:29:49.87000:29:49.880 sterilization of the products containing 00:29:52.21000:29:52.220 solid particles and for the heat 00:29:54.79000:29:54.800 treatment of cooling of tomato paste 00:29:57.22000:29:57.230 prior to aseptic processing so these are 00:30:01.00000:30:01.010 used to fer bulk inflow sterilization of 00:30:03.79000:30:03.800 the products which has certain solid 00:30:06.16000:30:06.170 particles as well are for the heat 00:30:08.44000:30:08.45000:30:10.60000:30:10.610 prayer to aseptic processing so that 00:30:13.45000:30:13.460 means high viscous high viscous liquid 00:30:18.66900:30:18.679 for hot so they can also be used with 00:30:24.07000:30:24.080 the liquid food with the solid particles 00:30:30.48000:30:30.490 food with solid particles so the tubular 00:30:39.54900:30:39.559 heat exchanger are also the heat 00:30:41.89000:30:41.900 transfer component in a tubular 00:30:43.87000:30:43.880 evaporators so here is what your double 00:30:48.28000:30:48.290 pipe heat exchanger so which is nothing 00:30:50.08000:30:50.090 but a tubular heat exchanger so your 00:30:52.48000:30:52.490 heart fluid goes in here are you can say 00:30:57.16000:30:57.170 your liquid food material is inside the 00:30:59.62000:30:59.630 tube liquid food so your heat medium or 00:31:05.91900:31:05.929 heating medium in terms of heating or 00:31:08.16900:31:08.179 cooling medium in terms of cooling flows 00:31:11.38000:31:11.390 this side she think not cooling medium 00:31:19.56000:31:19.570 okay so this is the shell and tube shall 00:31:24.34000:31:24.350 earn you 00:31:30.38000:31:30.390 this is the shell and tube heat 00:31:32.49000:31:32.500 exchanger where number of tubes so if 00:31:35.49000:31:35.500 you see number of tubes are put together 00:31:37.59000:31:37.600 in a bundle so then the shell side your 00:31:41.81000:31:41.820 normal heating or cooling medium will be 00:31:44.52000:31:44.530 flowing so this is heating or cooling 00:31:47.31000:31:47.320 medium heating or cooling medium so this 00:31:57.12000:31:57.130 is heating 00:32:02.78000:32:02.790 or cooling medium so inside that you've 00:32:09.87000:32:09.880 your food material is flowing so this is 00:32:12.90000:32:12.910 where in the industry where tubular heat 00:32:15.69000:32:15.700 exchanger looks like right and one more 00:32:18.90000:32:18.910 thing what we have seen is the triple 00:32:21.39000:32:21.400 pipe right so triple pipe is something 00:32:24.24000:32:24.250 like this right so we told so the inner 00:32:31.05000:32:31.060 pipe as well as the outer pipe right so 00:32:34.53000:32:34.540 in the both places you are heating or 00:32:38.19000:32:38.200 cooling medium is flowing in the middle 00:32:47.73000:32:47.740 of the pipe right in the middle pipe so 00:32:51.63000:32:51.640 your flow a liquid fluid is flowing 00:32:55.64000:32:55.650 liquid foodless know so this is tube in 00:33:02.16000:33:02.170 tube in tube heat exchanger so this is 00:33:06.54000:33:06.550 shell-and-tube this is tubular exchanger 00:33:09.21000:33:09.220 which has two concentric tubes so this 00:33:12.75000:33:12.760 is scrap the surface so we will see 00:33:14.97000:33:14.980 about the theory and come back so this 00:33:18.09000:33:18.100 is a clay right like shell and tube as 00:33:20.49000:33:20.500 well as tubular exchanger this is the 00:33:22.26000:33:22.270 basic types so in the tube your liquid 00:33:25.44000:33:25.450 food material is going so other tubes 00:33:27.78000:33:27.790 you are our tube our shell side you are 00:33:30.27000:33:30.280 heating or cooling medium is flowing so 00:33:33.18000:33:33.190 it is not necessary I need to heat or 00:33:35.91000:33:35.920 cold my liquid food with the hot fluid 00:33:39.66000:33:39.670 or cold fluid so there may be 00:33:41.79000:33:41.800 electrically rounded tubular exchanger 00:33:44.07000:33:44.080 also there so in that case it is called 00:33:46.20000:33:46.210 as Joule effect heater and these shell 00:33:50.37000:33:50.380 and tube heat exchangers are used or 00:33:53.34000:33:53.350 tubular heat exchangers are used to for 00:33:55.70000:33:55.710 liquid food which contain solid 00:33:58.32000:33:58.330 particles as well as the high viscous 00:34:01.95000:34:01.960 liquid food also can be handled in the 00:34:04.40000:34:04.410 tubular heat exchangers so the scrap the 00:34:08.01000:34:08.020 surface heat exchangers so which has a 00:34:10.29000:34:10.300 they consist of a jacketed cylinder a 00:34:12.84000:34:12.850 cooped with the central 00:34:14.37000:34:14.380 dating - sure with scrapping blades so 00:34:17.01000:34:17.020 that is right here so this is your 00:34:19.05000:34:19.060 jacket so in the middle you have a rotor 00:34:24.03000:34:24.040 right so the rotor has blades so this is 00:34:27.18000:34:27.190 the side view so this is blades so this 00:34:30.63000:34:30.640 is a rotor so this at this place 00:34:34.56000:34:34.570 you are liquid food with the high amount 00:34:38.16000:34:38.170 of solid particles stays there okay so 00:34:42.78000:34:42.790 they consist of a jacketed cylinder 00:34:45.06000:34:45.070 equipped with the central rotating - 00:34:47.16000:34:47.170 sure with scrapping blades so they can 00:34:49.53000:34:49.540 be horizontal or vertical the product is 00:34:52.50000:34:52.510 fed into the cylinder they rapidly 00:34:55.08000:34:55.090 rotating the rotating speed is about 600 00:34:58.65000:34:58.660 to 700 rpm and they spread scraps and 00:35:03.03000:35:03.040 moves the product as a flim over the 00:35:06.00000:35:06.010 wall the heating or cooling medium is 00:35:08.61000:35:08.620 fed into the jacket so here you have 00:35:11.52000:35:11.530 your heating or cooling medium so these 00:35:14.16000:35:14.170 rotors helping the products because it 00:35:17.19000:35:17.200 has high amount of solids because the 00:35:20.69000:35:20.700 scraplet surface heat exchanger is 00:35:23.07000:35:23.080 mainly used to for high viscous fluids 00:35:25.65000:35:25.660 or liquid food contains a large amount 00:35:28.86000:35:28.870 of solid particulates so for this 00:35:30.98000:35:30.990 application only this crapola surface 00:35:34.11000:35:34.120 heat exchangers are used so in that case 00:35:36.99000:35:37.000 so this blades are helping the solids 00:35:41.01000:35:41.020 liquid food with the high amount of 00:35:44.16000:35:44.170 solids to form a film layer near the 00:35:46.94000:35:46.950 jacketed one in the other side of the 00:35:50.01000:35:50.020 jacketed one you are heating our cooling 00:35:52.35000:35:52.360 medium is flowing so the scrap surface 00:35:55.83000:35:55.840 heat exchangers are used to for heating 00:35:57.99000:35:58.000 cooling highly viscous fluids and for 00:36:00.93000:36:00.940 slush freezing the continuous ice cream 00:36:04.20000:36:04.210 freezes and slush freezes or essentially 00:36:07.80000:36:07.810 scrap the surface heat exchanges with 00:36:10.53000:36:10.540 the refrigerant evaporating in the 00:36:12.60000:36:12.610 jacket so one thing is as I said earlier 00:36:15.96000:36:15.970 it need not be always hard fluid or cold 00:36:18.96000:36:18.970 fluid here the refrigerant is also used 00:36:21.57000:36:21.580 as a heating or cooling medium because 00:36:24.75000:36:24.760 it gets evaporated the less tempering 00:36:32.14000:36:32.150 okay so the scrapple exchanger is an 00:36:35.69000:36:35.700 expensive piece of equipment both in 00:36:38.12000:36:38.130 price as well as in operating cost 00:36:40.34000:36:40.350 because it has got many moving parts so 00:36:43.34000:36:43.350 the exchanges are expensive so the next 00:36:46.49000:36:46.500 one is very important heat exchangers in 00:36:49.43000:36:49.440 the food industry so it is almost came 00:36:51.89000:36:51.900 into existence in 1923 and in most of 00:36:55.34000:36:55.350 the pass tracing or a aseptic processing 00:36:57.68000:36:57.690 the plate type heat exchangers are used 00:37:00.26000:37:00.270 so the plate type heat exchangers are 00:37:03.20000:37:03.210 well established method for processing 00:37:05.93000:37:05.940 homogeneous products of low viscosity 00:37:08.32000:37:08.330 making them ideal for use within Diaries 00:37:12.43000:37:12.440 mostly in the past recession or aseptic 00:37:15.41000:37:15.420 processing of milk the plate heat 00:37:17.98000:37:17.990 exchangers consist of a series of plates 00:37:20.69000:37:20.700 connected on a frame the product and 00:37:23.78000:37:23.790 heating or cooling media flow in 00:37:26.69000:37:26.700 alternate channels in thin layers to 00:37:29.72000:37:29.730 provide good heat transfer conditions so 00:37:32.35900:37:32.369 I have a plates eight one side my heart 00:37:36.41000:37:36.420 fluid is flowing other side cold fluid 00:37:38.96000:37:38.970 other side hot fluid other side cold 00:37:41.24000:37:41.250 fluid so this is the way the alternative 00:37:43.49000:37:43.500 channels are arranged the plates are 00:37:45.92000:37:45.930 sealed by elastic sealing gasket 00:37:48.60900:37:48.619 cemented into a perforated gru right so 00:37:52.60900:37:52.619 generally the plates are of polished 00:37:54.92000:37:54.930 stainless steel which is of about 0.5 to 00:37:58.55000:37:58.560 1 point to 5 mm in thickness separated 00:38:01.97000:38:01.980 by 3 to 6 mm right 00:38:04.60900:38:04.619 so these plates of are of stainless 00:38:07.28000:38:07.290 steel the thickness of them is 0.5 to 00:38:10.01000:38:10.020 1.25 mm they are separated by the 00:38:12.74000:38:12.750 distance 3 to 6 mm okay so in these 00:38:16.64000:38:16.650 plates are separated by 3 to 6 mm and 00:38:19.88000:38:19.890 they are sealed by elastic sealing 00:38:21.98000:38:21.990 gasket cemented into a perforated groove 00:38:24.83000:38:24.840 so this we will see in picture so the 00:38:27.92000:38:27.930 surface of the plates is usually 00:38:30.05000:38:30.060 corrugated in order to increase the area 00:38:32.87000:38:32.880 available for heat transfer as well as 00:38:35.48000:38:35.490 enhance the turbulence present in the 00:38:38.06000:38:38.070 system resulting in a high thermal 00:38:40.91000:38:40.920 efficiency so these are corrugated to 00:38:43.88000:38:43.890 promote mainly the turbulence and also 00:38:48.08000:38:48.090 sometimes it also gives the strength to 00:38:50.84000:38:50.850 the plates which are stacked together 00:38:57.58000:38:57.590 okay so the thermal regeneration can in 00:39:01.10000:39:01.110 the plate type exchanges as we have seen 00:39:03.80000:39:03.810 in many of our lectures the thermal 00:39:06.23000:39:06.240 regeneration as possible which can lower 00:39:08.66000:39:08.670 the energy cost substantially then 00:39:11.24000:39:11.250 narrow gaps mean that the units are best 00:39:14.42000:39:14.430 suited for low viscosity homogeneous 00:39:17.27000:39:17.280 products because the gaps between the 00:39:19.85000:39:19.860 plates are very very narrow so we cannot 00:39:23.09000:39:23.100 handle the liquid food with the large 00:39:26.00000:39:26.010 amount of particulate solids because it 00:39:28.76000:39:28.770 gets in between the plates and further 00:39:31.37000:39:31.380 fouling can occur so attempts to process 00:39:34.31000:39:34.320 particulate products which is example is 00:39:36.89000:39:36.900 nothing but the fruit juices with the 00:39:38.84000:39:38.850 pulp right that cells may result in 00:39:41.39000:39:41.400 black two channels and eventually blown 00:39:44.00000:39:44.010 plates due to the pressure imbalance 00:39:45.83000:39:45.840 between the product and the media sites 00:39:48.53000:39:48.540 of the plates so for this reason only 00:39:51.50000:39:51.510 products with less than 10 percentage 00:39:53.69000:39:53.700 particulate content or normally 00:39:55.70000:39:55.710 recommended when processing with plate 00:39:58.10000:39:58.110 type heat exchanger so this has to be 00:40:00.50000:40:00.510 kept in mind so we cannot process the 00:40:03.05000:40:03.060 liquid foot with more than 10 percentage 00:40:06.11000:40:06.120 of the particulate content and the 00:40:08.42000:40:08.430 regeneration is possible in plate type 00:40:11.15000:40:11.160 heat exchangers which lowers the energy 00:40:13.58000:40:13.590 cost and there are many variations of 00:40:16.46000:40:16.470 the plate type heat exchanger so how to 00:40:18.77000:40:18.780 take care of each and every plate and 00:40:21.50000:40:21.510 which type of gross should be there and 00:40:23.72000:40:23.730 based on the product we can select them 00:40:26.12000:40:26.130 so which way we want the plate type heat 00:40:28.79000:40:28.800 exchanger to be designed so here we see 00:40:31.75000:40:31.760 so this is the plate type heat 00:40:34.55000:40:34.560 exchangers looks like so this is your 00:40:36.59000:40:36.600 upper bar so this is the head plate head 00:40:40.46000:40:40.470 plate in the sense header and this is 00:40:42.53000:40:42.540 the fall over right so in between the 00:40:44.84000:40:44.850 header and follower your plates were 00:40:46.85000:40:46.860 arranged so as I said so here your hot 00:40:50.51000:40:50.520 fluid is flowing and hear your heart 00:40:52.91000:40:52.920 fluid is flowing here you are 00:40:54.71000:40:54.720 a hot fluid is flowing so there is a 00:40:56.39000:40:56.400 mechanism which transfers this hard 00:40:59.24000:40:59.250 fluid to here and so here your cold 00:41:02.21000:41:02.220 fluid is flowing right so that means so 00:41:06.67000:41:06.680 this flows through the plate okay so 00:41:10.46000:41:10.470 this is the lower but this is upper but 00:41:13.06900:41:13.079 so in which there are two mechanism 00:41:16.01000:41:16.020 oneness the plates you can remove via 00:41:19.94000:41:19.950 bars or it can be hanged in the bar so 00:41:23.24000:41:23.250 if it is hanged in the bar it can be 00:41:25.19000:41:25.200 easily taken out because one of the 00:41:28.49000:41:28.500 advantage for this plate type heat 00:41:30.47000:41:30.480 exchanger is this is a module type right 00:41:32.66000:41:32.670 so in future if I want to increase the 00:41:35.75000:41:35.760 protection so I can just add one more 00:41:38.15000:41:38.160 module in the plate type heat exchanger 00:41:39.92000:41:39.930 so in that way the module can be easily 00:41:42.41000:41:42.420 added or removed based on the need of 00:41:45.26000:41:45.270 the process industry so that is the way 00:41:47.32900:41:47.339 we have seen right number of plates 00:41:48.98000:41:48.990 requirement right so for regeneration 00:41:51.23000:41:51.240 section how many number of plates are 00:41:53.17000:41:53.180 heating section how many number of 00:41:55.19000:41:55.200 plates on cooling section how many 00:41:56.96000:41:56.970 number of plates so we have estimated as 00:41:59.75000:41:59.760 a number of plates in the each section 00:42:02.66000:42:02.670 so in that way the plates can be hanged 00:42:05.18000:42:05.190 or the plates can be welded in the bar 00:42:08.35900:42:08.369 so that it can be removed in the later 00:42:10.97000:42:10.980 stage but hanging would give me 00:42:13.18000:42:13.190 advantage if I want to remove our are 00:42:16.01000:42:16.020 the plates and so this is the plate 00:42:18.29000:42:18.300 package and this bolts so this will come 00:42:21.85900:42:21.869 here so to stack the plates right it to 00:42:26.00000:42:26.010 keep them intact between the header and 00:42:29.00000:42:29.010 follower so these are various categories 00:42:32.24000:42:32.250 of plate configuration so this 00:42:34.67000:42:34.680 configuration is washboard so this is 00:42:36.98000:42:36.990 zigzag and this is sevran or herringbone 00:42:40.55000:42:40.560 the C type there are D typists 00:42:42.98000:42:42.990 protrusions and depressions and e type 00:42:46.22000:42:46.230 is washboard with secondary corrugations 00:42:48.71000:42:48.720 and F is oblique washboard there are 00:42:52.48000:42:52.490 different varieties right so that's what 00:42:55.37000:42:55.380 I told so when the fluid is passing 00:42:56.99000:42:57.000 through so it is designed in such a way 00:42:59.69000:42:59.700 to increase the heat transfer and to 00:43:04.16000:43:04.170 give further turbulence 00:43:07.68000:43:07.690 - the turbo lends to the fluid okay so 00:43:16.26900:43:16.279 that is the way it increases the heat 00:43:18.30900:43:18.319 transfer and if you compare your 00:43:21.21900:43:21.229 shell-and-tube module and plate module 00:43:23.70900:43:23.719 this is the way it looks like so in that 00:43:25.56900:43:25.579 way it is very compact compared to shell 00:43:29.49900:43:29.509 and tube heat exchanger so the advantage 00:43:32.52900:43:32.539 wise the capacity can be increased or 00:43:35.07900:43:35.089 decreased by adding or removing plates 00:43:37.53900:43:37.549 this I already discussed so that 00:43:39.99900:43:40.009 flexibility I have in the plate type 00:43:42.16000:43:42.170 heat exchanger the sanitation by opening 00:43:45.00900:43:45.019 the stack both sides of the entire 00:43:47.28900:43:47.299 exchange area are made accessible for 00:43:49.69000:43:49.700 cleaning and inspection so it is just 00:43:51.91000:43:51.920 the plate right in the plate the fluid 00:43:54.00900:43:54.019 is flowing so I can remove the plate 00:43:55.95900:43:55.969 very easily and clean them and inspect 00:43:58.56900:43:58.579 them when needed right so the sanitation 00:44:01.47900:44:01.489 wise it is very much advantageous and 00:44:03.57900:44:03.589 high heat transfer coefficient due to 00:44:05.85900:44:05.869 increase the turbulence in the narrow 00:44:07.77900:44:07.789 flow channel that's the way the 00:44:10.02900:44:10.039 corrugations were made and a compact 00:44:12.33900:44:12.349 heat exchange surface to volume ratio is 00:44:15.37000:44:15.380 very high so that is the way it is 00:44:17.22900:44:17.239 compact on the other hand disadvantage 00:44:19.98900:44:19.999 sight it is a narrow size of the flow 00:44:22.18000:44:22.190 channels results in high pressure drop 00:44:24.75900:44:24.769 and limits is used to only low viscosity 00:44:28.39000:44:28.400 fluids which does not contain large 00:44:32.01900:44:32.029 suspended particulates this is the 00:44:34.25900:44:34.269 disadvantage and also their need for 00:44:36.60900:44:36.619 gaskets gaskets in the sense so here if 00:44:39.75900:44:39.769 you see in this so this is nothing but 00:44:42.09900:44:42.109 an gaskets okay so which prevents the 00:44:46.71900:44:46.729 further leaking of the fluid right so 00:44:50.25900:44:50.269 the need for gaskets is very much 00:44:52.80900:44:52.819 disadvantageous one as I discussed there 00:44:55.56900:44:55.579 are many improvements made in these kind 00:44:58.29900:44:58.309 of heat exchanges for example there is 00:45:00.69900:45:00.709 something called double plate security 00:45:02.89000:45:02.900 system so that means the both the plates 00:45:05.17000:45:05.180 where welded and formed as a channel 00:45:07.77900:45:07.789 then after that these formed channels 00:45:10.53900:45:10.549 where further made together in the 00:45:13.87000:45:13.880 module by gaskets right so if there is 00:45:17.46900:45:17.479 any leakage between the plates then 00:45:20.49900:45:20.509 obvious 00:45:21.10900:45:21.119 it is known because it is kept as a 00:45:23.08900:45:23.099 channel so in that way the security 00:45:26.29900:45:26.309 system can be improved to avoid the 00:45:29.45000:45:29.460 leakage of the liquid foot product when 00:45:33.20000:45:33.210 it is heated so there are many 00:45:35.50900:45:35.519 improvements and also I say served 00:45:38.66000:45:38.670 earlier so all to be performed in the 00:45:41.20000:45:41.210 contamination free area so that one has 00:45:43.94000:45:43.950 to ensure while using any of the heat 00:45:46.60900:45:46.619 exchange equipment in the food 00:45:48.52900:45:48.539 processing industry so that sulphur heat 00:45:53.05900:45:53.069 exchanges so these are the references 00:45:55.70000:45:55.710 and additional resources what I have 00:45:57.73900:45:57.749 used in this particular lecture thank 00:46:00.55900:46:00.56900:46:01.23000:46:01.24000:46:23.84000:46:23.850
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