COOLING TOWER PFB SERIES

RANGE 10 - 1200 RT

PFB COOLING TOWERS Cooling towers are mainly used where it is necessary to reject considerable quantities of heat, by means of simple and economical method. Applications of this kind are:

- Industrial process systems where economical reasons dictate heat rejection by water recirculating systems, rather than by once – through systems.

- Air conditioning applications, utilizing water cooled condenser. Cooling towers series PFB are manufactured by FYROGENIS S.A. in 28 standard sizes covering a range from 10 up to 1200 refrigerant tons. Principle of Operation The operating principle of cooling towers is evaporative cooling, i.e. exchange of sensible and latent heat. The Water to be cooled is distributed over the wet deck surface by spray nozzles. Air is simultaneously blown upwards through the wet deck surface casing the vaporization of a portion of the water remaining in the liquid state. The cooled water flows to the pan and returns to heat source (e.g. condenser). The theoretical limit for the temperature of water leaving the cooling tower is the wet-bulb temperature of the surrounding air entering the tower. This limit is attained for infinite surface of contact. Design advantages Cooling towers series PFBB of FYROGENIS combine several important advantages as:

- Contact surface (wet deck) design for maximum efficiency, easy cleaning and replacement. - Noiseless operation. - Restriction of weight and volume. - Endurance to weather conditions. - Easy installation and maintenance.

GENERAL DESCRIPTION Series PFB cooling towers utilize counter flow arrangement (blow through). This permits smaller dimensions, in comparison with induced draft cooling towers, as well as fan operation with dry air, free of water drops. This has a significant effect on life duration, which is increased, practically, without limit. Also air is discharged vertically directed by the specially designed eliminators, without creating annoying drafts. Series PFB cooling towers comprise the following parts: Fan section Fan section comprises one or more double width, double inlet, forward curved centrifugal fans, having a protective inlet screen. Fans are statically and dynamically balanced at the factory, on automatic electronic machines. an selection, for every standard model, was made at low speed, for a given capacity. This, combined with the low outlet velocity, results in a smooth, noiseless operation. The use of centrifugal fans provides sufficient static pressure and permits thus connection of ductwork, if the tower is to be installed indoors. Fan shafts are selected so that operation speed is much lower than the first critical speed. Shaft bearings are self-aligning ball bearings, selected for continuous heavy duty and maximum service life. Fans are driven by electric motors and V-belts. Drives are protected by special belt-guards. Motors are 3-phase, with protection IP 54 and insulation class F. They are mounted on an adjustable base for belt tensioning. Motor position, under the sloping pan side, provides excellent protection. Pan section Pan is of triangular shape and is fabricated of heavy gauge hot-dip galvanized sheet steel. Pan is completely welded and after welding, the points of welding are covered with a special anticorrosive paint. The pan is kept constantly clean, because water flows continuously down its sloping sides. Any foreign matter is collected at the bottom of the pan and is easily removed.

On the side of the pan there is an overflow, float valve for automatic make-up water inlet, water outlet with mesh-type water strainer, drain and a watertight access door, permitting easy inspection of the interior of the pan. Wet-deck and water distribution section Wet deck surface (Packing) is made of cells in vertical position consisting of high density polyethylene grid. Air and water pass through marrow channels which, due to their shape, promote air turbulence, and thus increase efficiency, as air and water are uniformly distributed and remain in contact for a considerable period of time. Spray nozzles are open type, made of plastic material. Water is rotated in them, by means of a special device and is scattered evenly over the wet-deck surface. Nozzles have low pressure drop and this fact helps to reduce pumping costs for the tower water circuit, as the pump can be selected for a low head pressure. Another major advantage of open type nozzles is that they do not need frequent cleaning. Spray tree is so arranged as to insure even distribution of water over the wet deck. Nozzles are screwed to the headers and are easily removable for maintenance. Over the spray tree is the eliminator surface. Eliminators prevent water drops from getting out of the tower. Casing The whole structure is given a coating of anti-corrosive paint. PFB cooling tower can be delivered dismantled in two or three parts, to reduce weight and volume, and can be easily reassembled on site. Base Base is constructed of heavy steel frame and provides a strong and rigid support to the whole structure. PFB towers can be installed on two steel beams, running through the length of the tower (see chapter of installation). Towers are mounted on rubber-in-shear vibration isolators. These mountings accompany the tower as standard accessories. Sound attenuators PFB cooling towers can be equipped upon request with sound attenuators in the air inlet or air outlet.

COOLING CAPACITES Entering water ºF 95 90 95 90 95 90 97 95 97 95 97 95 temperature (ºC) (35,0) (32,2) (35,0) (32,2) (35,0) (32,2) (36,1) (35,0) (36,1) (35,0) (36,1) (35,0)

Leaving water ºF 85 80 85 80 85 80 87 85 87 85 87 85 temperature (ºC) (29,4) (26,7) (29,4) (26,7) (29,4) (26,7) (30,6) (29,4) (30,6) (29,4) (30,6) (29,4)

Entering air ºF 68 68 70 70 72 72 75 75 78 78 80 80 temperature (ºC) (20,0) (20,0) (21,1) (21,1) (22,2) (22,2) (23,9) (23,9) (25,6) (25,6) (26,7) (26,7)

C O

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C A

P C

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R T

PFB 10 22 14 20 11 16 9 16 15 18 10 11 9,6 PFB 15 27 18 25 16 23 13 22 18 19 15 16 12 PFB 20 33 24 30 22 29 19 29 25 24 20 23 16 PFB 25 39 30 36 27 32 23 31 31 31 25 26 17 PFB 30 49 37 47 33 44 28 44 38 37 30 33 24 PFB 35 54 42 51 38 48 33 48 42 42 35 38 28 PFB 40 59 48 58 42 53 38 52 48 48 40 43 33 PFB 45 70 55 68 48 63 41 62 56 54 45 47 36 PFB 50 78 58 76 54 72 48 72 58 59 50 54 40 PFB 60 87 70 85 66 82 59 82 70 70 60 66 47 PFB 75 115 93 113 82 109 74 109 94 93 75 82 59 PFB 100 158 123 152 123 145 88 144 122 122 100 115 78 PFB 125 170 148 168 136 160 128 159 149 149 125 134 104 PFB 150 250 180 235 160 220 140 220 188 181 150 161 123 PFB 200 268 241 273 209 273 190 273 239 240 200 209 169 PFB 225 378 278 352 241 325 208 326 278 270 225 240 182 PFB 250 402 308 378 262 358 236 357 308 305 250 260 205 PFB 300 505 361 480 322 440 282 440 369 367 300 316 245 PFB 350 540 426 540 376 503 330 503 430 425 350 368 292 PFB 400 538 481 672 423 541 372 540 458 481 400 418 331 PFB 450 745 550 732 485 653 387 647 552 550 450 472 373 PFB 500 797 598 762 530 702 476 701 603 603 500 531 416 PFB 600 1018 739 953 645 878 558 871 740 738 600 640 485 PFB 700 1076 849 1077 750 998 655 998 862 848 700 738 578 PFB 800 1081 961 1080 852 1080 753 1078 968 960 800 845 668 PFB 900 1534 1092 1425 960 1308 836 1310 1108 1100 900 958 722 PFB 1000 1610 1224 1572 1080 1440 930 1438 1243 1218 1000 1055 812 PFB 1200 1605 1436 1605 1280 1605 1130 1605 1450 1430 1200 1262 998

NOTE: The above capacities correspond to water circulation of 3 gpm/RT (684 lt/h/RT). PFB COOLING TOWERS SELECTION The model number of PFB towers implies capacity in refrigerant tons for temperatures of entering and leaving water 95°/85° F (35°/29.4° C) and wet bulb temperature of entering air 78° F (25.6° C). One cooling tower Refrigerant Ton equals 15000 Btu/h and not 12000 Btu/h. (The analogy of absorbed to rejected heat in a refrigerant cycle, in air conditioning applications with water cooled condenser, under full load, equals approximately the ratio 1,2:1,5) This way, cooling tower selection becomes simpler. In table above, performances of PFB cooling towers are given under various conditions. In order to correctly select the proper model for a given application, water flow rate or cooling capacity, entering and leaving water temperatures and entering air wet bulb temperature must be known. Example Given: 250 RT, entering / leaving water temperatures 95°/85° F, entering air wet bulb temperature 70° F. For the above given conditions, model PFB 350 has a capacity of 540 RT. Selection: PFB 350. Note: For selection under a set of conditions not given in the quick selection table, consult the company.

TECHNICAL CHARACTERISTICS

TYPE Air capacity Water flow Cooling capacity Fans Motors

cfm m³/h gpm It/h Btu/h w Nr. Type rpm Nr. (HP)

PFB 10 3.647 6.200 30 6 840 150.000 44.000 1 12 - 12 675 1 1,5

PFB 15 4.176 7.100 45 10.260 225.000 66.000 1 12 - 12 740 1 2,0

PFB 20 4.853 8.250 60 13.680 300.000 88.000 1 15 - 15 565 1 2,0

PFB 25 5.765 9.800 75 17.100 375.000 110.000 1 15 - 15 620 1 3,0

PFB 30 6.765 11.500 90 20.520 450.000 132.000 1 18 - 18 430 1 3,0

PFB 35 7.529 12.800 105 23.940 525.000 154.000 1 18 - 18 470 1 3,0

PFB 40 9.412 16.000 120 27.360 598.000 175.400 1 18 - 18 560 1 4,0

PFB 45 10.588 18.000 135 30.780 675.000 198.000 2 15 - 15 550 1 4,0

PFB 50 12.000 20.400 150 34.200 750.000 220.000 2 15 - 15 610 1 5,5

PFB 60 13.529 23.000 180 41.040 900.000 264.000 2 15 - 15 670 1 7,5

PFB 75 18.529 31.500 225 51.300 1.125.000 330.000 3 15 - 15 650 1 7,5

PFB 100 24.470 41.600 300 68.200 1.500.000 439.900 3 18 - 18 530 1 10,0

PFB 125 27.353 46.500 375 85.500 1.875.000 549.900 3 18 - 18 570 1 12,5

PFB 150 34.180 58.000 450 102 270 2.250.000 659.900 4 18 - 18 550 2 7,5

PFB 200 42.941 73.000 600 136.360 3.000 000 879.800 4 20 - 20 580 2 10

PFB 225 50.000 85.000 675 153.400 3.375.000 989.800 4 20 - 20 665 2 15

PFB 250 55.882 95.000 750 170.450 3.750.000 1.099.800 4 22 - 22 560 2 15

PFB 300 60.000 102.000 900 204.540 4.500.000 1.319.700 4 22 - 22 610 2 15

PFB 350 63.529 108.000 1.050 238.640 5 250.000 1 539.600 6 20 - 20 600 2 15

PFB 400 70.588 120.000 1.200 272 720 6.000.000 1.759.600 6 20 - 20 660 2 20

PFB 450 88.235 150.000 1.350 306.820 6.750.000 1.979.500 8 20 - 20 630 4 12,5

PFB 500 102.941 175.000 1.500 340.900 7.500.000 2 199.500 8 20 - 20 700 4 20

PFB 600 105.882 180.000 1.800 409.090 9.000.000 2.639.300 8 20 - 20 730 4 20

PFB 700 129.412 220.000 2.100 477.270 10.500.000 3.079.200 12 20 - 20 610 4 20

PFB 800 141.176 240.000 2.400 545.450 12.000.000 3.519.100 12 20 - 20 650 4 20

PFB 900 180.000 306 000 2.700 613.640 13 500 000 3.959.000 12 25 - 25 400 4 20

PFB 1000 200.000 340.000 3.000 681 800 15.000.000 4.398.900 12 25 - 25 430 4 20

PFB 1200 211.765 i 360.000 3.600 818.180 18.000.000 5 278.600 12 25 - 25 455 4 25

Note : - Cooling capacities are given for the following conditions. - Entering water temperature 95° F (35° C), leaving water temperature 85° F (29,4° C), - entering air wet bulb temperature 78° F (25,6° C).

Model with one fan and one motor

Model with three fans and one motor

Model with eight fans and for motors

Dimention wight

Model PFB 10-125

MODEL A B C D1 D2 D3 D4 D5 WEIGHTS (kg) PFB (mm) (mm) (mm) Empty Oper. 10 900 825 2135 2" 2" 1 / 2" 11 / 2" 3 / 4" 245 335 15 900 825 2135 2" 2" 1 / 2" 11 / 2" 3 / 4" 250 340 20 1000 1025 2135 2" 2" 1 / 2" 11 / 2" 3 / 4" 290 405 25 1000 1025 2135 2" 2" 1 / 2" 11 / 2" 3 / 4" 295 410 30 1300 1025 2135 3" 3" 1 / 2" 11 / 2" 3 / 4" 370 500 35 1300 1025 2135 3" 3" 3 / 4" 11 / 2" 3 / 4" 370 500 40 1300 1025 2335 3" 3" 3 / 4" 11 / 2" 3 / 4" 410 570 45 1900 1100 2335 3" 3" 3 / 4" 2" 1" 485 880 50 1900 1100 2335 3" 3" 1" 2" 1" 505 900 60 2000 1100 2335 3" 3" 1" 2" 1" 570 960 75 2900 1125 2335 4" 4" 1" 2" 1" 850 1420

100 3000 1125 2335 4" 4" 1" 2" 1" 880 1470 125 3300 1125 2335 4" 4" 1" 2" 1" 955 1455 150 2500 1950 2245 5" 5" 1" 2" 1" 1155 1805 200 3000 1950 2335 5" 5" 1" 2" 1" 1460 2105 225 2900 2500 2810 6" 6" 1" 2" 11 / 2" 1765 2730 250 2900 2500 3205 6" 6" 1" 2" 11 / 2" 1945 3015 300 2900 2500 3405 6" 6" 1" 2" 11 / 2" 2000 3070 350 3800 2800 3215 6" 6" 1" 2" 11 / 2" 2420 4205 400 3800 2800 3415 6" 6" 1" 2" 11 / 2" 2560 4345 450 5500 2800 2830 2 × 6" 8" 2 × 1" 2×11 / 2" 11 / 2" 3425 5750 500 5500 2800 3225 2 × 6" 8" 2 × 1" 2×11 / 2" 11 / 2" 3815 6140 600 5500 2800 3625 2 × 6" 8" 2 × 1" 2×11 / 2" 11 / 2" 3985 6310 700 7800 2800 3225 4 × 6" 2 × 8" 4 × 1" 4 × 11 / 2" 2 × 11 / 2" 5585 9390 800 7800 2800 3625 4 × 6" 2 × 8" 4 × 1" 4 × 11 / 2" 2 × 11 / 2" 6135 9490 900 12200 2800 3335 6 × 6" 2 × 10" 4 × 1" 4 × 11 / 2" 2 × 11 / 2" 9330 13430 1000 12200 2800 3535 6 × 6" 2 × 10" 4 × 1" 4 × 11 / 2" 2 × 11 / 2" 9530 13630 1200 12200 2800 3735 6 × 6" 2 × 10" 4 × 1" 4 × 11 / 2" 2 × 11 / 2" 9830 13930

Model PFB 150-400 Model PFB 450-1200 Water Connections

D1: Recirculation water inlet D2: Recirculation water oulet D3: Make-up water D4: Overflow D5: Drain

OPERATION AND CONTROL

Series PFB cooling towers can be controlled by water side control method.This method utilizes a three way diverting valve or a two way valve, bypassing water around the tower Valves modulate water flow through the tower, in accordance with the required outlet temperature. This method permits also free cooling operation during winter for covering reduced cooling loads (people, lights and solar) while the energy intensive chiller is shut off.

Legends 1. Cooling tower 2. Condenser 3. Water pump 4. Modulating valve (3- or 2-

way) 5. 5 Temperature sensor 6. Check valve 7. By-pass

INSTALLATION PFB cooling towers are installed on isolating base, especially when they are installed on the roof of building. This base is generally constructed of concrete with an intermediate layer of anti-vibration material. The base is extended through the entire surface occupied by the tower. The above base is always recommended, even in the case the tower is to be finally installed on steel beams. Transportation and rigging present no serious problems. In larger models, due to their weight, the unit can be transported in two or three different parts and assembled in its final position. For easy maintenance care must be taken for the following:

- Leave necessary space around the tower (about 3 m) so that parts needing maintenance are readily accessible.

- Install a valve in make up line. Also install a separate water tap for cleaning the tower. - Connect tower to drain system of the building. - Always install an electric switch near the tower to isolate motors independently of the

switch which may be installed in the machinery room, so that any independent maintenance action on the motors can be performed safely.

When the tower is first put in operation the following must be taken care of: - Check water filter and, if necessary, clean it from dirt that may have remained in the piping

system after completion. - Check drive to insure that there is a proper belt tension, and after 30 minutes of operation

readjust. MAINTENANCE To insure proper operation of towers as well as efficient operation and great life duration it is necessary to inspect, in regular time intervals, the major parts to insure they are in a proper condition. At least once in a year, before summer operation begins, the following maintenance actions must be performed:

- Lubricate the bearing housings. - Clean the tower from all foreign matter that may have accumulated internally. This is

easily done with a soft brush and fresh water. - Check condition of nozzles, and if necessary clean them. - Check condition of float valve, water filter and water level in the pan. - Check condition of external paint and restore where necessary.

Every two or three weeks during peak operating season check belts tension and adjust if necessary.

WATER TREATMENT Water treatment, is an essential part of the cooling tower operation and maintenance. Evaporation of water leaves certain solid remainders. Recirculation of water in the condenser cooling tower circuit, and the accompanying evaporation, increases the concentration of solids. This concentration must not be allowed to exceed certain limits, otherwise can cause corrosion problems. The most common method of facing this situation is through bleeding a certain quantity of water from the circuit and replacing it with a new quantity of fresh water. In PFB towers, there is a factory installed bleed line, connecting water inlet to the overflow. Through this line, a certain amount of water is continuously removed from the circuit and is constantly replaced with fresh make-up water. Theoretically, the rate of evaporation is 1.0% of circulating water, for 10° F between entering and leaving water. Maximum evaporation occurs when the tower operates in summer under a great temperature differential. The best approximation of the evaporation rate, for the great majority of ambient conditions, is 0.8% for every 10° F (5.5° C) temperature differential between entering and leaving water. The required blowdown, can be estimated from the following equation:

EHmHs

HmB ×−

= , where

B : rate of blowdown Hm : hardness of make-up water Hs : permissible hardness of recirculating water E : rate of evaporation It should be noted that the ratio in the above equation is independent from the units of hardness used, provided Hs and Hm are expressed in the same units. In order to correctly apply the above information, a sample analysis of water is required to determine hardness. The required amount of blowdown can then be determined and if it is found to be excessive, then the right solution is proper water treatment. Where water treatment is unavoidable the advice of a specialist is necessary and must be followed.

PUMP SELECTION To help select the proper pump for a given model and water flow rate, two charts are given below, where the pressure drop at the nozzles for various water flow rates can be found. To select the pump, first find the pressure drop at the nozzles, for a given model and flow rate. Add to this the pressure drop in the piping system, the pressure drop in the condenser and the necessary pump head to balance the difference in level between nozzles and water surface in the pan (practically the height of the tower, thus introducing a slight safety factor). The resulting head can be used to select the pump.

GUIDE SPECIFICATIONS MECHANICAL DRAUGHT COOLING TOWERS Furnish and install, as indicated on the drawings, mechanical draught cooling tower, factory assembled, blow through type. The tower shall have centrifugal fans and all moving parts shall be mounted and aligned at the factory. The tower shall be constructed of heavy gauge hot-dip galvanized steel sheets. CAPACITY The tower is to cool ………. gpm (m³/h) of water from ………. °F (°C) to ………. °F (°C) with ………. °F (°C) wet bulb of entering air. The tower shall operate under ………. ft W.G. (mm W.G.) external static pressure. Fan section The tower shall have on one or both sides centrifugal fans, double inlet, of the forward curved type. Fan housings shall have aerodynamically shaped inlet cones and inlet screens. Air shall be discharged directly in the pan Fan housings shall be fixed on the sloping sides of pan so that the fans are under the main tower. Fans shall be statically and dynamically balanced at the factory, to ensure smooth, vibration free operation Fan shafts shall be constructed from high quality steel. Shaft bearings shall be self-aligning pre-lubricated ball bearings. Fans shall be driven by electric motors and V-belts. Drives shall be protected by means of special belt guards. Motors shall be 3-phase with insulation class F and IP 54, suitable for operation on ………... Volts and ………. Hz. They shall have dynamically balanced rotors and pre-lubricated ball bearings. The motors shall be mounted on a adjustable base, permitting easy belt tension. Pan section Pan shall be of triangular shape and shall be constructed of heavy gauge hot-dip galvanized steel sheets. Pan shall be completely welded and shall have an extra anti-corrosive paint at the points of welding applied after completion of its construction. Pan shall have overflow, make-up water inlet with float valve, water outlet with mesh-type water strainer and a large water-tight access door permitting easy inspection of the interior of the pan. Wet deck and water distribution section Wet deck surface (packing) shall be constructed of cells in vertical position consisting of high density polyethylene grid, forming passages for air and water. Packing shall be easily cleaned and replaced. Spray nozzles shall be open type, low pressure drop plastic nozzles, screwed on the headers. Spray tree shall insure uniform distribution of spayed water over the wet-deck Water inlet shall be connected to the overflow by means of a bleed line. A hand valve shall be factory-installed on the bleed line. Eliminators shall be made of modules and shall be easily removable, making spray tree accessible Casing The casing shall be constructed of heavy gauge hot-dip galvanized steel sheets, properly reinforced for maximum rigidity. The base of the tower shall be constructed from heavy steel beams. Casing shall have brackets, properly arranged for rigging the tower to the place of its final installation. The tower shall be type PFB ………. as manufactured by FYROGENIS S.A. Fyrogenis S.A., due to continuous improvement of its products, reserves the right to change any specifications without notice.

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