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Heat Exchangers Condensers and Reboilers Training

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Kind: captions
Language: en

00:00:11.090
there are many different types of shell
00:00:13.400 00:00:13.410 and tube heat exchangers and each one is
00:00:15.920 00:00:15.930 designed to accomplish a specific
00:00:17.480 00:00:17.490 function in a process condensers are one
00:00:21.019 00:00:21.029 type of shell and tube heat exchanger
00:00:22.820 00:00:22.830 they're designed to convert gases or
00:00:25.160 00:00:25.170 vapors into their liquid States here's
00:00:28.130 00:00:28.140 an example of a typical condenser it's
00:00:30.650 00:00:30.660 used to turn steam into water so that
00:00:33.050 00:00:33.060 the water can be reused in a steam
00:00:35.060 00:00:35.070 generating system condensers can also be
00:00:38.270 00:00:38.280 used to cool and condense product
00:00:40.250 00:00:40.260 vapours for example the vapor produced
00:00:42.980 00:00:42.990 in this distillation column flows into a
00:00:45.470 00:00:45.480 condenser and is converted to a liquid
00:00:47.690 00:00:47.700 depending on the process involved the
00:00:50.450 00:00:50.460 liquid formed in a condenser may be
00:00:52.250 00:00:52.260 referred to by different names the water
00:00:54.950 00:00:54.960 that's formed when steam is condensed is
00:00:57.080 00:00:57.090 called condensate on the other hand the
00:01:00.260 00:01:00.270 liquid that's formed when product or
00:01:02.270 00:01:02.280 by-product vapors are condensed is often
00:01:04.819 00:01:04.829 called distillate to get a better
00:01:07.370 00:01:07.380 understanding of how a condenser
00:01:08.990 00:01:09.000 operates let's look at an illustration
00:01:10.999 00:01:11.009 of a condenser that uses cooling water
00:01:13.849 00:01:13.859 to condense product vapours into
00:01:15.739 00:01:15.749 distillate this condenser has a shell
00:01:19.599 00:01:19.609 tubes tube sheets a vapor Inlet a
00:01:24.459 00:01:24.469 cooling water inlet called a head a
00:01:27.459 00:01:27.469 distal eight outlet a cooling water
00:01:30.919 00:01:30.929 outlet head and a receiver on this type
00:01:35.300 00:01:35.310 of condenser the cooling water heads may
00:01:37.639 00:01:37.649 also be referred to as water boxes
00:01:40.359 00:01:40.369 during operation on the tube side of the
00:01:43.550 00:01:43.560 condenser cooling water enters through
00:01:45.889 00:01:45.899 the inlet head passes through the tubes
00:01:48.349 00:01:48.359 and flows out of the condenser through
00:01:50.840 00:01:50.850 the outlet head on the shell side of the
00:01:53.809 00:01:53.819 condenser vapour passes through the
00:01:55.940 00:01:55.950 inlet and flows around the tubes when
00:01:59.239 00:01:59.249 the vapor comes into contact with the
00:02:01.039 00:02:01.049 cool surfaces of the tubes heat is
00:02:03.319 00:02:03.329 transferred from the vapor through the
00:02:05.330 00:02:05.340 walls of the tubes to the cooling water
00:02:07.339 00:02:07.349 as heat is transferred to the cooling
00:02:10.070 00:02:10.080 water the vapor cools and condenses on
00:02:12.860 00:02:12.870 the surfaces of the tubes the condensed
00:02:15.350 00:02:15.360 vapor or distillate drips off the tubes
00:02:18.050 00:02:18.060 and falls to the bottom of the shell it
00:02:20.540 00:02:20.550 then flows through the distillate outlet
00:02:22.700 00:02:22.710 and into
00:02:23.420 00:02:23.430 receiver the receiver receives or
00:02:26.089 00:02:26.099 collects the distillate that drains from
00:02:28.399 00:02:28.409 the shell of the condenser the
00:02:30.170 00:02:30.180 distillate is usually sent on for
00:02:31.970 00:02:31.980 further processing or to storage now as
00:02:34.880 00:02:34.890 the vapor condenses a low pressure is
00:02:37.459 00:02:37.469 created inside the condenser this low
00:02:39.979 00:02:39.989 pressure draws more vapor into the
00:02:41.750 00:02:41.760 condenser in order for vapor to continue
00:02:44.539 00:02:44.549 to flow into the condenser the pressure
00:02:46.610 00:02:46.620 inside the condenser must be lower than
00:02:49.009 00:02:49.019 the pressure of the vapor entering it
00:02:51.520 00:02:51.530 condensers can be operated at almost any
00:02:54.410 00:02:54.420 pressure as long as it's below that of
00:02:56.479 00:02:56.489 the entering vapor for example the vapor
00:02:59.479 00:02:59.489 entering this condenser is at 250 psi
00:03:02.569 00:03:02.579 and the condenser is operating at a
00:03:04.729 00:03:04.739 pressure slightly less than that on the
00:03:07.429 00:03:07.439 other hand this condenser is operating
00:03:09.679 00:03:09.689 under a vacuum because the vapor
00:03:11.569 00:03:11.579 entering it is near atmospheric pressure
00:03:14.000 00:03:14.010 in a condenser that operates under a
00:03:16.369 00:03:16.379 vacuum the condensing vapor normally
00:03:18.890 00:03:18.900 maintains the vacuum however when the
00:03:21.860 00:03:21.870 condenser is started up auxiliary
00:03:24.050 00:03:24.060 equipment such as a steam jet air
00:03:26.240 00:03:26.250 ejector may be needed to establish the
00:03:28.550 00:03:28.560 initial vacuum a steam jet air ejector
00:03:32.240 00:03:32.250 consists of a steam Inlet a nozzle a
00:03:35.740 00:03:35.750 suction port and a combining tube
00:03:39.789 00:03:39.799 normally the combining tube is connected
00:03:42.140 00:03:42.150 directly to a small condenser called an
00:03:44.599 00:03:44.609 air ejector condenser as the steam
00:03:47.149 00:03:47.159 passes through the nozzle it is
00:03:48.979 00:03:48.989 accelerated as the fast-moving steam
00:03:52.009 00:03:52.019 leaves the nozzle it draws air in from
00:03:54.469 00:03:54.479 the main condenser through the suction
00:03:56.479 00:03:56.489 port and to the combining tube where the
00:03:59.059 00:03:59.069 air mixes with the steam this mixing
00:04:02.089 00:04:02.099 process is referred to as entraining as
00:04:04.749 00:04:04.759 the steam and air mixture flows out of
00:04:07.610 00:04:07.620 the air ejector an area of low pressure
00:04:10.129 00:04:10.139 forms in the air ejector suction port
00:04:12.589 00:04:12.599 this low-pressure draws additional air
00:04:15.319 00:04:15.329 in from the main condenser this air also
00:04:17.930 00:04:17.940 becomes entrained in the steam and the
00:04:20.300 00:04:20.310 process continues the final result is
00:04:23.029 00:04:23.039 that the pressure in the main condenser
00:04:25.040 00:04:25.050 decreases in some systems the air
00:04:28.760 00:04:28.770 ejector and its condenser are shut down
00:04:31.040 00:04:31.050 after a vacuum has been established in
00:04:33.110 00:04:33.120 the main condenser but in some processes
00:04:35.659 00:04:35.669 the air rejectors room
00:04:37.189 00:04:37.199 and service to remove air and other
00:04:39.260 00:04:39.270 gases that won't condense you see non
00:04:42.830 00:04:42.840 condensable gases can build up inside a
00:04:45.200 00:04:45.210 condenser when this happens the gases
00:04:47.540 00:04:47.550 insulate or blanket the tubes and reduce
00:04:50.480 00:04:50.490 the amount of heat transferred in the
00:04:52.010 00:04:52.020 condenser as a result less vapor will
00:04:54.830 00:04:54.840 condense and the pressure inside the
00:04:56.809 00:04:56.819 condenser will increase the increase in
00:04:59.779 00:04:59.789 pressure may reduce the flow of vapor or
00:05:02.029 00:05:02.039 it could stop the flow all together as
00:05:04.309 00:05:04.319 an operator you may be responsible for
00:05:07.159 00:05:07.169 the operation of many different types of
00:05:09.200 00:05:09.210 heat exchangers including condensers so
00:05:12.019 00:05:12.029 it's important for you to understand how
00:05:14.209 00:05:14.219 they can be started up and shut down to
00:05:17.749 00:05:17.759 get an idea of the steps involved in
00:05:19.640 00:05:19.650 starting up and shutting down a
00:05:20.899 00:05:20.909 condenser
00:05:21.709 00:05:21.719 we'll watch an operator as he places a
00:05:24.170 00:05:24.180 condenser in service and then takes it
00:05:26.450 00:05:26.460 off line the condenser we'll use in our
00:05:29.239 00:05:29.249 example is part of a distillation
00:05:30.890 00:05:30.900 process it operates at a pressure well
00:05:33.619 00:05:33.629 above atmospheric and the cooling in the
00:05:36.079 00:05:36.089 condenser is accomplished by water that
00:05:38.239 00:05:38.249 passes through the tubes before starting
00:05:41.240 00:05:41.250 up this condenser the operator verifies
00:05:43.700 00:05:43.710 that the valves on the condenser and its
00:05:45.740 00:05:45.750 associated equipment are properly lined
00:05:48.139 00:05:48.149 up according to his startup procedure
00:05:50.769 00:05:50.779 with the valve checks completed the
00:05:53.570 00:05:53.580 operator opens the vent valve on the
00:05:55.639 00:05:55.649 tube side of the condenser then he
00:05:57.920 00:05:57.930 partially opens the cooling water inlet
00:06:00.110 00:06:00.120 valve the sound of escaping air means
00:06:02.540 00:06:02.550 that cooling water is filling the tube
00:06:04.490 00:06:04.500 side of the condenser when the tube side
00:06:07.189 00:06:07.199 is filled a stream of water flows from
00:06:09.679 00:06:09.689 the vent then the operator closes the
00:06:12.469 00:06:12.479 tube side vent valve with the vent valve
00:06:15.200 00:06:15.210 shut the operator fully opens the
00:06:17.510 00:06:17.520 cooling water inlet valve the cooling
00:06:20.239 00:06:20.249 water flow is controlled by the outlet
00:06:22.429 00:06:22.439 valve so the operator partially opens
00:06:25.309 00:06:25.319 the cooling water outlet valve to a
00:06:27.110 00:06:27.120 predetermined position to establish flow
00:06:29.809 00:06:29.819 through the condenser at this point the
00:06:32.629 00:06:32.639 control room is contacted and the
00:06:34.550 00:06:34.560 process can be started when the
00:06:37.100 00:06:37.110 distillate reaches a predetermined level
00:06:39.110 00:06:39.120 in the receiver the distillate pump is
00:06:41.959 00:06:41.969 started and the condenser startup is
00:06:44.749 00:06:44.759 complete now for a condenser that
00:06:47.899 00:06:47.909 operates under a vacuum the air ejectors
00:06:50.509 00:06:50.519 would be
00:06:51.020 00:06:51.030 farted before the process fluid flow has
00:06:53.180 00:06:53.190 started this would remove the non
00:06:55.340 00:06:55.350 condensable gases from the condenser and
00:06:57.530 00:06:57.540 create the initial vacuum in addition to
00:07:00.740 00:07:00.750 starting up a condenser operators are
00:07:03.050 00:07:03.060 also involved in taking condensers out
00:07:05.270 00:07:05.280 of service during a condenser shutdown
00:07:08.660 00:07:08.670 if the flow of cooling fluid is stopped
00:07:10.970 00:07:10.980 before the process fluid flow the
00:07:13.280 00:07:13.290 condenser could overheat and be damaged
00:07:15.530 00:07:15.540 once the process has been shut down the
00:07:18.800 00:07:18.810 condenser can be shut down for
00:07:20.420 00:07:20.430 maintenance the operator shuts down the
00:07:22.970 00:07:22.980 condenser by closing the cooling water
00:07:24.950 00:07:24.960 inlet valve and closing the cooling
00:07:28.010 00:07:28.020 water outlet valve since the condenser
00:07:30.680 00:07:30.690 is being shut down for maintenance the
00:07:32.690 00:07:32.700 tube side will need to be drained that's
00:07:35.060 00:07:35.070 done by opening the tube side vent valve
00:07:37.310 00:07:37.320 and the tube side drain valve once the
00:07:40.610 00:07:40.620 tube side is drained the shutdown is
00:07:42.800 00:07:42.810 complete in some cases it may be
00:07:46.100 00:07:46.110 necessary to purge a condenser with an
00:07:48.410 00:07:48.420 inert gas after shutdown purging removes
00:07:51.440 00:07:51.450 vapors that could promote a fire when
00:07:53.420 00:07:53.430 exposed to air when a condenser is up
00:07:55.970 00:07:55.980 and running
00:07:56.570 00:07:56.580 operators regularly monitor its
00:07:58.790 00:07:58.800 performance keeping a close watch on
00:08:01.310 00:08:01.320 condenser operation can help ensure that
00:08:03.770 00:08:03.780 the condenser is working properly let's
00:08:06.830 00:08:06.840 take a look at some of the routine
00:08:08.210 00:08:08.220 checks that operators typically make in
00:08:10.460 00:08:10.470 order to identify problems and ensure
00:08:12.980 00:08:12.990 that a condenser operates safely and
00:08:15.020 00:08:15.030 efficiently one important check is the
00:08:18.530 00:08:18.540 level in the receiver this can be
00:08:20.780 00:08:20.790 checked using a sight glass on the
00:08:22.520 00:08:22.530 receiver or from a display or a chart
00:08:25.400 00:08:25.410 recorder in the control room if the
00:08:28.100 00:08:28.110 receiver level is too high the condenser
00:08:30.560 00:08:30.570 shell could flood reducing the
00:08:32.450 00:08:32.460 condensers efficiency if the level in
00:08:34.910 00:08:34.920 the receiver gets too low equipment
00:08:37.160 00:08:37.170 located downstream of the condenser
00:08:38.960 00:08:38.970 could be damaged for example if the
00:08:42.530 00:08:42.540 receiver level gets too low the pump
00:08:44.810 00:08:44.820 that's used to pump this delayed out
00:08:46.430 00:08:46.440 could cavitate the cavitation could
00:08:48.950 00:08:48.960 prevent the pump from operating properly
00:08:50.840 00:08:50.850 and damage the pump a controller on the
00:08:53.840 00:08:53.850 receiver automatically maintains level
00:08:56.120 00:08:56.130 an abnormal level could be an indication
00:08:58.580 00:08:58.590 of a problem with the controller a low
00:09:01.490 00:09:01.500 level could also be an indication of a
00:09:03.890 00:09:03.900 problem with the
00:09:04.850 00:09:04.860 cooling water flowing through the
00:09:06.080 00:09:06.090 condenser another important operator
00:09:08.990 00:09:09.000 check is the units temperatures and
00:09:11.150 00:09:11.160 pressures these indications can be
00:09:13.580 00:09:13.590 checked on instruments attached to the
00:09:15.410 00:09:15.420 condenser or on displays in the control
00:09:18.320 00:09:18.330 room one pressure reading that is
00:09:20.780 00:09:20.790 important to check is the receivers
00:09:22.700 00:09:22.710 pressure if the pressure in the receiver
00:09:25.070 00:09:25.080 drops too low the product liquid may
00:09:27.800 00:09:27.810 flash back into a vapor the condensers
00:09:30.980 00:09:30.990 pressure is also important to check on
00:09:33.310 00:09:33.320 condensers that operate under a vacuum
00:09:35.950 00:09:35.960 insufficient vacuum may affect the
00:09:38.120 00:09:38.130 efficiency of the condenser too little
00:09:40.850 00:09:40.860 vacuum can result from steam pressure
00:09:43.310 00:09:43.320 being too low with the air ejector from
00:09:46.130 00:09:46.140 air leaking into the condenser from too
00:09:48.830 00:09:48.840 little cooling water flow or from the
00:09:51.560 00:09:51.570 cooling water temperature being too high
00:09:53.780 00:09:53.790 many condensers have control valves that
00:09:56.780 00:09:56.790 regulate the unit's cooling water flow
00:09:58.490 00:09:58.500 an abnormal cooling water temperature
00:10:01.100 00:10:01.110 could be an indication of a problem with
00:10:03.590 00:10:03.600 the control system or with the cooling
00:10:05.840 00:10:05.850 water system contamination in a
00:10:07.940 00:10:07.950 condenser may be caused by a tube leak
00:10:10.130 00:10:10.140 in the condenser one way to check for
00:10:13.100 00:10:13.110 contamination is to take a sample of the
00:10:15.740 00:10:15.750 lower pressure fluid and test it for the
00:10:17.960 00:10:17.970 presence of the higher pressure fluid in
00:10:19.820 00:10:19.830 some cases contamination in the sample
00:10:22.640 00:10:22.650 can be seen in addition to sample test
00:10:25.520 00:10:25.530 results conductivity and pH readings of
00:10:28.520 00:10:28.530 cooling water may indicate a tube leak
00:10:30.350 00:10:30.360 if there is any indication of
00:10:32.450 00:10:32.460 contamination it's important to
00:10:34.520 00:10:34.530 determine the source of the problem and
00:10:36.110 00:10:36.120 take the appropriate corrective action
00:10:38.150 00:10:38.160 in this part of the program we looked at
00:10:41.030 00:10:41.040 how condensers operate and we examine
00:10:43.550 00:10:43.560 some typical condensers startup and
00:10:45.530 00:10:45.540 shutdown procedures we also covered some
00:10:48.260 00:10:48.270 of the basic checks that operators
00:10:49.910 00:10:49.920 typically make on condensers now let's
00:10:52.610 00:10:52.620 try some practice questions on this
00:10:54.350 00:10:54.360 material on the shell side of the
00:10:56.300 00:10:56.310 condenser vapor passes through the inlet
00:10:58.880 00:10:58.890 and flows around the tubes when the
00:11:01.850 00:11:01.860 vapor comes into contact with the cool
00:11:03.800 00:11:03.810 surfaces of the tubes heat is
00:11:05.780 00:11:05.790 00:11:07.820 00:11:07.830 00:11:09.830 00:11:09.840 00:11:12.560 00:11:12.570 00:11:15.350 00:11:15.360 the surfaces of the tubes
00:11:16.950 00:11:16.960 the condensed vapor or distillate drips
00:11:19.800 00:11:19.810 off the tubes and falls to the bottom of
00:11:21.990 00:11:22.000 the shell it then flows through the
00:11:24.060 00:11:24.070 distal aid outlet and into the receiver
00:11:26.310 00:11:26.320 when the tube side is filled a stream of
00:11:29.610 00:11:29.620 water flows from the vent then the
00:11:31.860 00:11:31.870 operator closes the tube side vent valve
00:11:34.579 00:11:34.589 contamination in a condenser may be
00:11:36.660 00:11:36.670 caused by a tube leak in the condenser
00:11:39.320 00:11:39.330 one way to check for contamination is to
00:11:42.630 00:11:42.640 take a sample of the lower pressure
00:11:44.130 00:11:44.140 fluid and test it for the presence of
00:11:46.350 00:11:46.360 the higher pressure fluid in some cases
00:11:48.920 00:11:48.930 contamination in the sample can be seen
00:11:51.120 00:11:51.130 in addition to sample test results
00:11:53.940 00:11:53.950 conductivity and pH readings of cooling
00:11:56.760 00:11:56.770 water may indicate a tube leak if there
00:11:59.160 00:11:59.170 is any indication of contamination it's
00:12:01.620 00:12:01.630 important to determine the source of the
00:12:03.449 00:12:03.459 problem and take the appropriate
00:12:05.130 00:12:05.140 corrective action Ketel type reboilers
00:12:07.829 00:12:07.839 are a type of shell and tube heat
00:12:09.210 00:12:09.220 exchanger they're primarily used to
00:12:11.730 00:12:11.740 vaporize process liquids from a
00:12:13.560 00:12:13.570 distillation column and return only the
00:12:16.050 00:12:16.060 vapor back to the column let's look at
00:12:18.449 00:12:18.459 an illustration of this type of reboiler
00:12:20.519 00:12:20.529 to see how it works the major parts of
00:12:23.640 00:12:23.650 this reboiler include a shell a tube
00:12:26.910 00:12:26.920 bundle a tube Inlet a tube outlet a
00:12:31.070 00:12:31.080 shell Inlet baffles a vapor outlet an
00:12:36.410 00:12:36.420 overflow Weir and a liquid outlet in
00:12:40.220 00:12:40.230 this reboiler steam is used to heat the
00:12:43.380 00:12:43.390 process liquid when the steam passes
00:12:45.780 00:12:45.790 through the tubes it transfers some of
00:12:48.030 00:12:48.040 its heat to the process liquid as the
00:12:50.430 00:12:50.440 steam transfers its heat it condenses
00:12:53.010 00:12:53.020 into water which is returned to a steam
00:12:55.410 00:12:55.420 generating system the process liquid
00:12:58.290 00:12:58.300 from the distillation column enters the
00:13:00.210 00:13:00.220 reboiler here the liquid flows around
00:13:02.910 00:13:02.920 the baffles and tubes and receives heat
00:13:05.579 00:13:05.589 from the steam the overflow Weir acts as
00:13:08.460 00:13:08.470 a dam to ensure that the tubes in the
00:13:10.620 00:13:10.630 reboiler always stay covered with the
00:13:12.840 00:13:12.850 process liquid as the process liquid is
00:13:15.810 00:13:15.820 heated some of the liquid boils off as a
00:13:18.240 00:13:18.250 vapor the vapor separates from the
00:13:20.610 00:13:20.620 liquid and collects in the dome-shaped
00:13:22.440 00:13:22.450 space above the tubes in the shell and
00:13:24.750 00:13:24.760 then flows back to the distillation
00:13:26.760 00:13:26.770 column the process liquid that does not
00:13:29.760 00:13:29.770 boil off
00:13:30.780 00:13:30.790 is pumped from the reboiler and sent to
00:13:33.150 00:13:33.160 where it can undergo additional
00:13:34.860 00:13:34.870 processing or be stored a shell and tube
00:13:37.770 00:13:37.780 heat exchanger known as a thermo siphon
00:13:39.990 00:13:40.000 reboiler is used to heat process liquid
00:13:42.840 00:13:42.850 from a distillation column to produce a
00:13:45.060 00:13:45.070 vapor then the vapor and the process
00:13:47.670 00:13:47.680 liquid flow back to the column let's
00:13:50.250 00:13:50.260 look at an illustration of this type of
00:13:51.900 00:13:51.910 reboiler to see how it works the major
00:13:54.990 00:13:55.000 components of this reboiler include a
00:13:57.450 00:13:57.460 shell a tube Rundle a tube side Inlet a
00:14:01.590 00:14:01.600 tube side outlet a shell side Inlet and
00:14:05.760 00:14:05.770 a shell side outlet in this reboiler oil
00:14:10.020 00:14:10.030 that's heated in a furnace is used to
00:14:12.180 00:14:12.190 heat the process liquid the hot oil
00:14:14.280 00:14:14.290 passes through the tubes and is then
00:14:16.650 00:14:16.660 returned to the furnace where it is
00:14:18.420 00:14:18.430 reheated the process liquid from the
00:14:21.300 00:14:21.310 distillation column enters the reboiler
00:14:23.490 00:14:23.500 shell and passes around the tubes heat
00:14:26.490 00:14:26.500 from the hot oil vaporizes part of the
00:14:28.770 00:14:28.780 process liquid the mixture of liquid and
00:14:31.440 00:14:31.450 vapor is then returned to the
00:14:33.120 00:14:33.130 distillation column the flow of the
00:14:35.880 00:14:35.890 process liquid and vapor is caused by
00:14:38.370 00:14:38.380 the difference between the density of
00:14:39.990 00:14:40.000 the liquid entering the reboiler and the
00:14:42.270 00:14:42.280 density of the heated mixture that's
00:14:44.010 00:14:44.020 returning to the distillation column the
00:14:46.650 00:14:46.660 heated mixture in the reboiler is less
00:14:48.660 00:14:48.670 dense than the liquid coming in from the
00:14:50.490 00:14:50.500 column this difference in density causes
00:14:53.550 00:14:53.560 the heated mixture to rise out of the
00:14:55.500 00:14:55.510 reboiler and return to the column the
00:14:57.960 00:14:57.970 result is a natural circulation between
00:15:00.300 00:15:00.310 the reboiler and the distillation column
00:15:02.100 00:15:02.110 as an operator you may be responsible
00:15:05.160 00:15:05.170 for the proper operation of reboilers
00:15:07.380 00:15:07.390 like other components in a process
00:15:09.600 00:15:09.610 reboiler should be checked periodically
00:15:11.700 00:15:11.710 to ensure that they're operating
00:15:13.650 00:15:13.660 properly one important check that should
00:15:16.530 00:15:16.540 be made is the level in the reboiler
00:15:18.450 00:15:18.460 this check is made by observing the
00:15:20.940 00:15:20.950 level in the reboiler sight glass the
00:15:24.120 00:15:24.130 tubes in a reboiler must be covered with
00:15:26.130 00:15:26.140 the process liquid if the level in the
00:15:28.290 00:15:28.300 reboiler drops too low the tubes could
00:15:30.720 00:15:30.730 overheat and be damaged on the other
00:15:32.970 00:15:32.980 hand a level that is too high can be a
00:15:35.370 00:15:35.380 problem too for example if the level in
00:15:38.070 00:15:38.080 a kettle type reboiler gets too high the
00:15:40.860 00:15:40.870 vapor and liquid will not separate
00:15:42.600 00:15:42.610 properly
00:15:43.630 00:15:43.640 a mixture may flow back into the
00:15:45.280 00:15:45.290 distillation column on a thermo siphon
00:15:48.190 00:15:48.200 type reboiler it's important to check
00:15:50.530 00:15:50.540 the circulation of process fluid through
00:15:52.630 00:15:52.640 the reboiler on thermosyphon reboilers
00:15:55.240 00:15:55.250 the circulation is created by the
00:15:58.030 00:15:58.040 difference between the density of the
00:15:59.890 00:15:59.900 liquid entering the reboiler and the
00:16:02.020 00:16:02.030 density of the mixture of vapor and
00:16:03.730 00:16:03.740 liquid leaving the reboiler this
00:16:06.550 00:16:06.560 circulation can be disrupted if the
00:16:08.800 00:16:08.810 liquid level in the distillation column
00:16:10.300 00:16:10.310 is too high if the level in the column
00:16:13.270 00:16:13.280 rises too high it can block the reboiler
00:16:16.000 00:16:16.010 outlet line and disrupt the flow with
00:16:19.330 00:16:19.340 both kettle type and thermosyphon
00:16:21.550 00:16:21.560 reboilers instrument readings should be
00:16:23.770 00:16:23.780 checked frequently in many cases the
00:16:26.590 00:16:26.600 temperature in the reboiler is dictated
00:16:28.630 00:16:28.640 by the temperature needed in the
00:16:30.010 00:16:30.020 distillation column for example a
00:16:32.740 00:16:32.750 controller that monitors temperature in
00:16:35.020 00:16:35.030 this column sends a signal to a steam
00:16:37.360 00:16:37.370 control valve to either decrease or
00:16:39.760 00:16:39.770 increase the amount of steam flow to the
00:16:41.830 00:16:41.840 reboiler on many kettle type reboilers
00:16:44.800 00:16:44.810 the process liquid is pumped from the
00:16:46.780 00:16:46.790 column to the reboiler by a pump the
00:16:49.390 00:16:49.400 pump should be checked to ensure that it
00:16:51.280 00:16:51.290 is operating properly in this topic we
00:16:54.250 00:16:54.260 looked at two types of reboilers kettle
00:16:56.770 00:16:56.780 type reboilers and thermosyphon
00:16:58.840 00:16:58.850 reboilers we examined the major
00:17:00.850 00:17:00.860 components of these reboilers and we saw
00:17:03.430 00:17:03.440 how they operate we also took a look at
00:17:05.980 00:17:05.990 some of the checks that can be made on
00:17:07.420 00:17:07.430 reboilers to ensure that they're
00:17:09.340 00:17:09.350 operating properly now let's try some
00:17:11.949 00:17:11.959 practice questions on reboilers the
00:17:14.590 00:17:14.600 process liquid from the distillation
00:17:16.240 00:17:16.250 column enters the reboiler here the
00:17:19.180 00:17:19.190 liquid flows around the baffles and
00:17:20.980 00:17:20.990 tubes and receives heat from the steam
00:17:23.380 00:17:23.390 the overflow Weir acts as a dam to
00:17:26.410 00:17:26.420 ensure that the tubes in the reboiler
00:17:28.210 00:17:28.220 always stay covered with the process
00:17:30.460 00:17:30.470 liquid as the process liquid is heated
00:17:33.040 00:17:33.050 some of the liquid boils off as a vapor
00:17:35.680 00:17:35.690 the vapor separates from the liquid and
00:17:38.380 00:17:38.390 collects in the dome-shaped space above
00:17:40.720 00:17:40.730 the tubes in the shell and then flows
00:17:42.820 00:17:42.830 back to the distillation column the
00:17:45.550 00:17:45.560 process liquid that does not boil off is
00:17:47.830 00:17:47.840 pumped from the reboiler and sent to
00:17:50.320 00:17:50.330 00:17:52.060 00:17:52.070 processing or be stored the process
00:17:54.850 00:17:54.860 liquid from the distillation column
00:17:56.200 00:17:56.210 enter
00:17:57.200 00:17:57.210 the reboiler shell and passes around the
00:17:59.450 00:17:59.460 tubes heat from the hot oil vaporizes
00:18:02.539 00:18:02.549 part of the process liquid the mixture
00:18:05.000 00:18:05.010 of liquid and vapor is then returned to
00:18:07.159 00:18:07.169 the distillation column the flow of the
00:18:10.100 00:18:10.110 00:18:12.590 00:18:12.600 00:18:14.299 00:18:14.309 00:18:16.519 00:18:16.529 00:18:18.289 00:18:18.299 00:18:20.899 00:18:20.909 00:18:22.909 00:18:22.919 00:18:24.769 00:18:24.779 00:18:27.799 00:18:27.809 00:18:29.779 00:18:29.789 00:18:32.240 00:18:32.250 00:18:34.549 00:18:34.559 00:18:36.610 00:18:36.620 one important check that should be made
00:18:39.139 00:18:39.149 is the level in the reboiler this check
00:18:41.899 00:18:41.909 is made by observing the level in the
00:18:43.730 00:18:43.740 reboiler sight glass the tubes in a
00:18:46.970 00:18:46.980 reboiler must be covered with the
00:18:48.500 00:18:48.510 process liquid if the level in the
00:18:50.539 00:18:50.549 00:18:53.000 00:18:53.010 00:18:55.250 00:18:55.260 00:18:57.620 00:18:57.630 problem too
00:18:58.279 00:18:58.289 for example if the level in a kettle
00:19:00.649 00:19:00.659 type reboiler gets too high the vapor
00:19:03.350 00:19:03.360 and liquid will not separate properly
00:19:05.389 00:19:05.399 and the mixture may flow back into the
00:19:07.549 00:19:07.559 distillation

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