Document BR0wkr7wbzpL09BqjY4y9wJx8
discharged through the fan exhaust. Each fan is equipped with
a vibration switch which will cut the fan's power if
vicration becomes too great, this is a safety feature which
to pro lone the lit* of -fit**
sneJ
i* ted
parts.
NOTE: In winter months, it is not unusual for ice to form on the slats inside the tower even though the return water temperature may be as high as 100-110 degrees F. If ice is noticed, the fan should be shut down on that cell as the tower structure is not designed to withstand the added weight of ice.
TREATMENT:
1) CHLORINE- Chlorine is used to minimize algae inside the tower itself. Chlorine is fed via a one-ton chlorine cylinder and an aspirator system. The controlling range for chlorine is 0.1-0.4 ppm
2) BETZ 25R.- Bets 25K is a mixture of BETZ 20K (which is an inhibitor used to prevent the formation of galvanic cells (corrosion) and provide a protective coating on the steel inside the exchangers) and BETZ 2020 which is a dispersant (used to remove the unusable phosphates found in the make-up water). The controlling range for filtered phosphates is lb20 ppm and the indication for 2020 level is the difference between filtered and unfilterd phosphates. If the difference becomes greater than 3 ppm, there is inadequate dispersant in the system to remove the unusable phosphates and can lead to fouling of the exchanger.
SL 009365
3) CALCIUM- Calcium levels of less than 120 ppm are desirable to minimise the fouling potential in the exchangers. The calcium level is controlled by blowing down the return water to the ditch via an automatic blowdown system. However, leaving the automatic valve wide open and throttling the manual block valve allows for easier control of calcium and less upsets in tower levels. Also, cycles (which is the ppm of calcium in the basin divided by the ppm of calcium in the make-up water) are used to assure that the proper amount of retention time of the chemicals in the exchangers is achieved. Cycles of 6-8 are optimum.
4) PH- The controlling range for PH is 7.2-7.8 and is controlled by adding soda ash to low PH water, and adding Sulfuric acid to high PH water. High PH's can lead to dissolved compounds losing their solubility and dropping out of suspension, thus becoming scale forming and may lead to exchanger fouling. Low PH's can erode the protective film on the metal and may erode the metal itself. Therefore, the PH must remain in the desired range to assure maximum protection from corrosion and fouling.
CONFIDENTIAL"
Subject to P^?tpjstrict Court of 14th
! LOW LEVEL I'M COOL IMG""" TOWER !
uPERATOR 6 NAME______ _________ _ DATE:
_______ _
*********** S#^*****##*******###*^** *##*#****##***#*** ******
.. 1. VERIFY 1_0W LEVEL ALARM IN COOLING TOWER BY VISUALLY CHECKING LEVEL.
_2,.
IF LEVEL IS LOW, CHECK THE CONDITION OF ALL OTHER BASINS AND OBSERVE THE SABINE WATER MAKE UP VALVE AND ENSURE IT IS MAKING UP WATER AT A RATE TO CONTROL BASIN LEVEL. ADJUST THE LEVEL CONTROLLER TO INCREASE MAKEUP IP NECESSARY. KEEP LEAD OPERATOR INFORMED OF YOU ACTIONS AND CONDITION OF COOLING TOWER.
.. 3. ADJUST COOLING TOWER RETURN WATER TO ENSURE EQUAL HEAT DISTRIBUTION.
_4. IF LEVEL IN COOLING TOWER BASINS CONTINUES TO DECREASE, THEN ADDITIONAL WATER CAN BE ADDED FROM SEVERAL SOURCES DEPENDING ON OPERATING CONDITIONS. A. BLOCK OFF ANY BLOW DOWN 8. SWITCH ANY WATER GOING TO THE CLEAN WATER DITCH TO THE BASINS. C. USE LEVEL CONTROLLER BYPASS D. IF LOW LEVEL IS IN #1, 2, OR 3 BASINS, RAISE LEVEL IN #4 TO INCREASE OVERFLOW. E. USE WELL WATER MAKE AS ANOTHER SOURCE OF MAKEUP F. TRIP SPRINKLER SYSTEM TO COOLING TOWER IN FIRE HOUSE.
-EEP YOUR OPERATOR AND LEAD OPERATOR INFORMED OF COOLING TOWER BASIN LEVELS AND OF ALL YOU ACTIONS TO CONTROL. THE LEVEL. LOSS OF COOLING TOWER WATER TO THE UNITS IS A CRITICAL SITUATION.
_6.
SEVERAL THINGS CAN CAUSE A LOW LEVEL IN THE COOLING TOWER, BUT WE HAVE SEVERAL SAFE GUARDS TO KEEP US INFORMED, A. LOW AND HIGH LEVEL ALARMS B. AMP METERS ON ALL PUMPS WITH DEVIATION ALARMS IF
THE AMPS DROP BELOW THE RED LINE SET POINT. C. CHECK VALVES ON PUMP DISCHARGE. D. SEVERAL. SOURCES OF MAKE-UP WATER E. MEANS OF CROSS CONNECTING COOLING TOWER BASINS.
SL 009366
SL 009367
CONFIDENTIAL: Subject to Protective Order of 14th Judicial District Court
No. 91-1145
EDC/yPCfl COOLING TOWERS
Often times the cooling towers seem a trivial part of llano `.'perat ions, and due to the seldom need for attention, th~ aforementioned is somewhat justified. But in reality, the cooling tower system is a vital necessity in the ahemical process. The loss of cooling water to process condensers can cause extremely high pressures on distillation columns resulting in environmental releases, out of spec product, or worse, injury. Therefore, careful attention to basin levels, pump and fan operation, and water temperature are an extremely important part of the operators daily rounds.
OPERATION
Cooling tower water is pumped through process condenser via a total of eight (8) pumps. The basins of nos. 1,2 & 3 towers are equalized through a common suction line and have six (6) pumps associated with it (of which there are normally only 4-5 pumps in service at any one time [a minimum of 4 pumps should be used to insure sufficient water flow to the condensers]). Number four (4) cooling tower has a separate suction and return line from nos. 1,2 & 3, and has two (2) pumps on it's suction (of which only 1 pump at a time is needed for normal operation). There is a suction and a discharge tie-in between the two sets of towers which can be used to optimize tower performances when the heat load is unbalanced.
Towers one, two, and three supply water to the process condensers in the two EDC plants, TCE section, and the D.H. still. Number four tower supplies water to the VDC Reactor, VDC Still, old no.3 EDC plant, and the TCE Stripper product exchangers. Due to the small heat load assigned to number four cooling tower, the basin temperature is noticeably lower than that of nos.1,2 & 3. Therefore it is advantageous to distribute some of number four tower's water to the processes that are cooled by the other three towers. This is done by the suction/discharge tie-ins mentioned earlier, and also by a tie-in by which number four cooling tower water (that has passed through the VDC Reactor and VDC Still condensers) is routed through a booster pump and discharged to the supply line of the other towers. This tie-in is located in the VDCM
Q.V 6 3. .
NOTE : Due to the high amperage draw on nos. 7 & 8 and the booster pump, you should not attempt to run more than two (2) of these three pumps at any one time. Number four 480V bus cannot handle the load and will trip off. The normal amperage draw on pumps 1 through 6 is approximately 75 amps, nos. 7,8 and the booster pump average approximately 175 amps.
If an amperage draw of less than fifty (50) amps is
CONFIDENTIAL*
court
noticed on pumps 1 through 6, or leas than 150 on 7,8 & the
bo.-.:ter pump, then the pump ic not operating at it's capacity
an:] X tj
a
eh n
.
ci
i;
_L
iji f
te attended to. t ion , it shou Id
If be
the pump isolated
cannot be primed due and rep o rted to th &
'.mi t t - er;'i LI 1 i for repairs, and another p ump s aij 4u. 1 d be put i
. - 'v ^ v i e X; -ji - d e c1. For p riming purpose s , an as p irato r i in
; wh ich i d r Ven by well water ) is hook ed to th tfr bowl S 'j. -i.
^ ,' unt
h i*
1i
p
urn it
p; L
S
1V his aspirate r 1 in e is n ceded due to the fact
not to be pu t that the we 1 I
in s e r v io wa te r u .`die*
is discharged to the cooling tower basin and is not a
suitable make-up water except in an emergency.
The level in the cooling towers is maintained by two level control valves (one on tower no.2, and one on tower no. 4 tower) which supply treated Sabine River water to the tcwere for level control. There are high and low level alarms located on the SDC panel board for towers number three and four. As stated earlier, loss of cooling water is critical, therefore a low level alarm on the towers should !.:e attended to without delay. If for some reason adequate 8 Rhine water is not available, for make-up, well water can be used. In case of emergency a fire hose or sprinkler system can be used to restore tower level to normal operation. Another source of make-up water is the return water from no 1 and no.2 EDC freon condensers. These condensers have the capability of using either Sabine or cooling tower water. When on Sabine water their returns are extra make-up and may need to be diverted to the ditch if tower levels exceed the high alarm point.
NOTE: When these freon condensers are on cooling' tower water diversion to the ditch is in effect blowdown.
There are screens located at the suction pits of each fewer which are used to filter the water and not allow trash or debris to enter pump suctions. When the screens become dirty a "waterfall" is created and screens must be cleaned. If a z-reens go unattended, a vortex may form and allow air to be e . eked into the pumps resulting in cavitation and loss of jo.iinfe on process condensers. On the other hand, a high level alarm is not critical, but can be costly if towers are allowed ho overflow (due to loss of expensive chemicals which ar^ aided to treat cooling water [see TREATMENT]).
Each tower has two (2) cells in which the return water is cooled for recirculation. The water is returned to the top of the tower via the return risers and allowed to freefall to the basin. There are numerous slats positioned so that the falling water is broken into droplets which allows the neat to be removed much easier than trying cool a solid stream of water. The cooling is provided by an updraft of air created by the fan located atop the tower cells; air is culled in through the open section at the tower bottom and
SL 009368
CONFIDENTIALI COOLING TOWER SAC NUMBERS Subject to Protective OrF
of 14th Judicial District c.. No. 91-1145
COOLING TOWER PUMPS (55) AND MOTORS (50)
1
55-538
50-1558
*7
55-540
50-1559
yt a
55-813
50-5648
4.
55-1623
50-1552
5.
55-984
50-1900
55-1143
50-2266
~f7 a
55-1511
50-2866
8.
55-1512
50-2867
TOWER
FANS {57)
FAN MOTORS
1-1 (WEST)
57-263
50-1948'
1-2 (EAST)
57-264
50-2822
2-1 (S)
*TMi__ |--i JL jL.
(N)
3-1 (S) (N)TT..... *-->
57-296 57-314
57-361 57--436
50-1489 50-1534
50-6517 50-2267
1 (S) (M)/i --
T 4TM
57-265 57-266
50-2844 50-2845
SEAR BOXES (52) 52-121 52-122
52-142 52-151 52-172 52-260
52-336 52-555
SL 009369
Subject to Protective Order of 14th Judicial District Court . No. 91-1145
CoOU^Os water. DlT&.i&aTt0f4
COOLING TOUEH WATER
11
crt
Coo) < ''6 Tvtij c.cL
SL 009372
CONFIDENTIAL: Subject to Protective Order of 14th Judicial District Court
No. 91-1145
EDC/VDCM COOLING WATER DISTRIBUTION 5/1 I /SO
-j SiKIPPtN LUNU j i-i 71-1520
-*4 VDC RX STMS COOLER t-1 71-2153
l -- i TiT hf*vy sTii.i cnun I
*1 71-1467
i
-- I -J TCE HEAVY STILL CONO.I 4 [ #2 7 1-646
-- I -t4 voc oh still cond. 71-1601
t--r
2
" + + > 4 I
TCE PRODUCT COOLER |----- -
71 - i 2D I
j*- %
JSJ
VOC STILL C0N0. 71-1204
VDC REACTOR CONDENSER 7! -!84fl
CONDENSATE COOLER!
71-1203
I
*
"T"
1
n 4
i <-
tUL PLAN I
II RX CAS 5EP 71-731
_| #1 RX COND.
1__________
ESC STMS REC COND
"I 7I-2S22
EOC BTM REC COND 71-2437
STRIPPER CONDENSE! 71-461
#2 RX CAS SEP 71-4R7
*2 RX CONDENSER j 71-460
SL 009373
H STILL CONO 7I-16S
I PRODUCT COOLER 71-613
#2 PRODUCT COOLER 71-SOS
STRIPPER CONOENER 71-810
RX CAS SEP COND 71-061
#1 RX CONDENSER | 71-162
#2 RX CONDENSER