HEAT EXCHANGERS Instructions For Using This Manual This is your manual. You should write The following general procedure is recom- \ your name on the cover. Upon completion mended for using this manual: you will find it helpful to keep it in an 1. Turn to Page 1. Read the material until accessible place for future reference. you come to the first problem or ques- Problems may be included throughout the tion. text. The solutions to the problems are given 2. Work the first problem or answer the at the end of the book. The last page is a question, and enter the answer in the validation sheet which has a number of proper space in ink. [f the problem or questions and problems covering the entire question is shown in both English and manuaL metric units of measurement, answer The manual will be used in ｾｲ｡ｩｮｩｮｧ＠ pro- only the part in units of measurement grams all over the world. In some countries, that you use. glish units of measurement such as feet, 3. Compare your answer with that shown gallons, pounds, etc., are used. In other on the reverse side of the Valida tion countries, metric measurement units, such pages. Answers to problems in English as meters, liters, kilograms, etc., are used. units of measurement are shown on the In order for the manual to be of maximum back of the second Validation page, use, both metric and English units are shown. and answers in metric units are shown The metric unit always appears first, and on the back of the first Validation page. the English unit follows in brackets [ l. If your answer is correct, continue Example: the temperature is 25' C [77' F]. reading until you come to the next The metric equivalent of the English unit problem and work it. If not, restudy wili be rounded off to the nearest whole the manual until you understand the number to simplify the text and examples. reason for your error. Rework the A pressure of 150 psi may be shown as 10 problem if necessary. Leave your wrong bars, when the exact equivalent is 10.34 bars. answer and note the correct one. This will keep you from making the same If you are working in English units, you may find it helpful to mark out the parts mistake later on. that are in metric units, and vice versa. 4. Proceed stepwise as shown above until ｾ＠ Some of the Figures have units of mea- you have completed the text. surement. In such cases, two Figures are The above approach will require thought, included. The first one uses metric units, making mistakes, and rethinking the situa- and the Figure number is followed by the tion. Concentrate on two things - the how letter A (Example: Figure lA). The second and the why. Do not cheat yourself by tak- Figure will be on the next page and will ing short-cuts or looking up the answers in have English units. [t will be the same num- advance. It saves time and errors but pro- ber as the first one, but it will be followed duces no real understanding. Your future by the letter B (Figure lB). If you use metric depends on how efficiently you perform your units, be sure to refer to Figures followed job and not on how rapidly you proceed by the letter A; if you use English units, through this manual. Since this is your refer to Figures followed by the letter B. manual, any errors you make are private. Training For Professional Performance This manual is one of a series for your use It will also teach you how and whyequip- in learning more about equipment that you ment functions. work with in the oilfield. Its purpose is to In order for you to learn the contents of assist in developing your knowledge and the manual, you must dig out the pertinent skills to the point that you can perform your facts and relate them to the subject. Simply work in a mOTe professional manner. reading the material and answering the The manual was prepared so that you can questions is not enough. The more effort you "learn its contents on your own time, with· make to learn the material the more you ou t the assistance of an instructor or class- will learn from the manuaL room discussion. Educators refer to learning Teaching yourself requires self discipline by self-study as Programmed Learning. It and hard work. In order to prepare ｹｯｵｲｳｾｬｦ＠ is a method widely used in all industries as for the sacrifice you will have to make, you a means of training employees to do their should set goals for yourself. Your ultimate job properly and teach them how to perform goal is to perform your work in a professional higher rated jobs. manner. Training is one step in reaching that You can demonstrate your desire to be a goal. Application of what you learn is an- professional by taking a positive attitude other. Seeking answers to questions is a third. toward learning the contents of this manual Once you have established your final goal, and others that are applicable to your job. you must determine the means for reaching A part of professional training is that of that goal. You may decide, for example, that validating the trainee's knowledge of the you must complete a series of 10 or 15 man- subject. Validation is for your benefit to uals to get the basic knowledge and skills indicate that you have taught yourself the you need. After you decide which training material contained in the manuaL material is required, you should set a time r The author of this manual has years of table for completing each section of the experience in operating petroleum equip- material. ment. He also has the technical knowledge Achieving your final goal may take more of how and why petroleum equipment func- than a year, and will require hours of hard tions. The text was written for use by per- work on your part. You will know you have sonnel with little or no previous experience achieved your goal when you understand with petroleum equipment. Consequently, how and why to operate oilfield equipment some of the rna terial may be familiar to you in order to obtain the maximum product at if you have experience with oilfield equip- the lowest cost. Your sacrifice will have been ment. From such experience, you have worth-while from the satisfaction of know- observed the eft'ect of making operating ing that you can perform your job in a changes. The manual will help explain why methodical professional manner, instead of the changes occurred that you observed. a trial-and-error-approach. ABBREVIATIONS & SYMBOLS USED IN THIS MANUAL MEANING EXAMPLE Temperature difference Temp diff is 100 Pressure difference Pres diff is 15 psi or ｢｡ｾｳ＠ METRIC UNIT ABBREVIATIONS ler liter 10 Itr: 10 liters lcr/hr liCers per hour 20 Itr/hr: 20 liters per hour m or mer meter 15 m: 15 meters em cenCimecer 10 cm: 10 centimeters km kilometer 5 km: 5 kilometers m3 cubic meCers 10 m3: 10 cubic meters m3/hr cubic me cers per hour 10 m3/hr: 10 Cll mtr per hr m3/d cubic meCers per day 10 m3/d: 10 ell mtr per day kcal kilocalories 20 kcal: 20 kilocalories kcal/hr kilocalories per hour 20 kcal/hr: 20 kilocalories per hr kcal/m3 kilocalories per cubic 9500 kcal/m3: 9500 kilocalories meCer of gas per cubic meter kcal/kg kilocalories per kilogram. 10 000 kcal/kg: 10 000 kilocalories per kilogram gm gram 10 gm: 10 grams kg kilogram. 25 kg: 25 kilograms kg/ cm2 or bar kilograms per square cen- SO bars: SO kg per sq em timeter of pressure bars a kilograms per sq em of SO bars a: SO kg per sq cm absolute absolute pressure square meter 100 m2: 100 square meters ENGLISH UNIT ABBREVIATIONS gal gallon 10 gal: 10 gallons gpm gallons per minute 25 gpm: 25 gallons per minute gph gallons per hour 25 gph: 25 gallons per hour ef cubic feet 20 cf: 20 cubic feet cfm cubic feet per minute 50 cfm: 50 cubic feet per min cfd cubic feet per day 50 cfd: 50 cubic feet per day Mcfd thousand eu ft per day SO ｍ｣ｦ ｾ Ｚ＠ ｾＧＩｵｲ［ＧＨｦｕｵｾ＠ -eu"): c-vee" (fay MMcfd million cu ft per day 50 MMcfd: 50;000,000 ell fe per day BTU British Thermal Unit BTU/hr British Thermal Units/hr 50 BTU/hr: so BTU per hour MBTU/hr thousand BTU per hour 30 MBTU/hr: 30,000 BTU per hr MMJ3TU/hr million BTU per hour 10 MMBTU/hr: 30,000.000 BTU per hr BTU/cu ft BTU per cubic foot of gas 1000 BTU/Cll ft: 1000 BTU per ell ft BTU/lb BTU per pound 20,000 BTU/lb: 20,000 BTU per Ib Ib pound 10 lb: 10 pounds psi pounds per square inch of 750 psi: 750 Ib per sq in pressure psia pounds per square inch of 750 psia: 750 lb per sq in abs absolute pressure bbl barrel 20 bbl : 20 barrels BPD barrels per day 100 BPD, 100 barrels per day BOPD barrels of oil per day 100 BOPD: 100 bbl oil per day BWPD barrels of ｾ｡ｴ･ｲ＠ per day 100 BWPD": 100 bbl water per day MEPD thousand barrels per day 10 HEPD: 10,000 bbl per day sq ft square foot 25 sq ft: 25 square feet HEAT EXCHANGERS INDEX I. TYPES OF EXCHANGERS A. Shell and Tube Exchangers ......••.... ..•••.... ..•. ..... 2 B. Hairpin Exchangers .... ....... .. ...... ..•••••.... •... .. 11 C. Aerial Coolers .... ... ...... .......... ..••.... ..••. ... . 13 D. Hiscellaneous Types of Exchangers ......••... ...••. .. .. 18 II. PRINCIPLES OF HEAT TRANSFER A. General .•....... ..............••......••... .... •. .. .. 20 B. Temperature Difference ...... ..••. .....••.... ...•.. ... 22 C. Resistance to Flow of Heat .... .•••. ..••••••...••.... . 31 D. Area ...................•.•••.••••••• •••••••• •••••••• ,32 III. APPLICATION OF EXCHANGERS A. Shell and Tube .... ...... ...••• .... ..••..... ..• ..... . 38 B. Hairpin ... ..... ............ ..•.... ..••.......•...... 39 C. Coils ... .... .. .... ...••.. ...•.•... ....•.•....••... .. 40 D. Aerial Coolers .... ....•.....•••.. ....••. .. ...•• ..... 40 IV. OPERATION OF EXCHANGERS A. Shell and Tube or Hairpin ... .•••. ....••.... ...••.. .. . 41 B. Aerial Coolers .... ..... ......•••....••• ......••... ... 1.2 V. TROUBLESHOOTING EXCHANGERS A. Shell and Tube Exchangers .. .. ........ .••.. .. ..••.... .. 43 B. Aerial Coolers ..... ....... ...... .... .••••...... ••... .. 43 VI. GASOLINE PLANT EXCHANGER PROBLEMS A. Gas-to-Gas Exchanger .............. ...••....... ••..... 45 B. Gas Chiller ......... ... ...... ...... .••••••... .•. ..... 48 TABLE I, TYPICAL EXCHANGER COEFFICIENTS .. .....•.... .. .. •... ... 55 TABLE II, EXTERNAL SURFACE AREA OF TUBES .....•••.•.. .••••.. ... 56 VALIDATION - Metric Units ...... .. .... ........ .....••.......•.. 59 SOLUTIONS TO PROBLEMS - Metric Units .... .••. ......••.. ........ 60 VALIDATION - English Units .................................... 61 SOLUTIONS TO PROBLEMS - English Units ....•• .... ...•.... .... ... 62 • v ABBREVIATIONS & SYMBOLS USED IN THIS MANUAL SYHBOL MEANING EXAMPLE ｾ＠ Temperature difference 6t ., 100 : Temp diff is 10° ap Pressure difference 6P - IS: Pres diff is 15 psi or bars METRIC UNIT ABBREVIATIONS ltr liter 10 Itr: 10 liters Itt'/hr liters per hour 20 Itr/hr: 20 liters per hour m or mtr meter 15 m: 15 meters em centimeter 10 em: 10 centimeters km kilometer 5 km: 5 kilometers m3 cubic meters 10 m3: 10 cubic meters m3/hr cubic meters per hour 10 m3/hr: 10 cu mtr per hr m3/d cubic meters per day 10 m3/d: 10 Cll mtr per day kcal kilocalories 20 keal: 20 kilocalories kcal/hr kilocalories per hour 20 kcal/hr; 20 kilocalories per hr kcal/m3 kilocalories per cubic 9500 kcal/m3: 9500 kilocalories meter of gas per cubic meter keal/kg kilocalories per kilogram 10 000 keal/kg: 10 000 kilocalories per kilogram gm gram 10 gm: 10 grams kg kilogram 25 kg: 25 kilograms kg/cm2 or bar kilograms per square cen- 50 bars: 50 kg per sq em timeter of pressure bars a kilograms per sq em of 50 bars a: 50 kg per sq em absolute absolute pressure square meter 100 m2: 100 square meters ENGLISH UNIT ABBREVIATIONS gal gallon 10 gal: 10 gallons gpm gallons per minute 25 gpm: 25 gallons per minute gph gallons per hour 25 gph: 25 gallons per hour cf cubic feet 20 cf: 20 cubic feet cfm cubic feet per minute 50 cfm: 50 cubic feet per min cfd cubic feet per day SO cfd: 50 cubic feet per day Mefd thousand cu ft per day SO Mcfd: 50,000 cu ft per day MMcfd million cu ft per day SO MMefd: 50,000,000 cu ft per day BTU British Thermal Unit BTU/hr British Thermal Units/hr 50 BTU/hr: 50 BTU per hour MBTU/hr thousand BTU per hour 30 MBTU/hr: 30,000 BTU per hr MMBTU/hr million BTU per hour 10 MMBTU/hr: 30,000,000 BTU per hr BTU/eu ft BTU per cubic foot of gas 1000 BTU/eu ft: 1000 BTU per eu ft BTU/lb BTU per pound 20,000 BTU/lb: 20,000 BTU per lb lb pound 10 Ib: 10 pounds psi pounds per square inch of 750 psi: 750 lb per sq in pressure psia pounds per square inch of 750 psi.: 750 lb per sq in abs absolute pressure bbl barrel 20 bbl: 20 barrels BPO barrels per day 100 BPO: 100 barrels per day BOPO barrels of oil per day 100 BOPO: 100 bbl oil per day BWPO barrels of water per day 100 BWPO: 100 bbl water per day MBPO thousand barrels per day 10 MBPO: 10,000 bb1 per day sq it square foot 25 sq ft: 25 square feet vi -1- HEAT EXCHANGERS Heat exchangers are used to conserve heat and save fuel, or to supply heat required by a process. The simplest heat exchanger is a kitchen pan used to boil water. Heat is transferred from the heating element on the stove to the water in the pan. An ice tray in a refrigerator is another simple heat ex- changer. A heat exchanger can be thought of as any piece of equipment in which heat is transferred from a warm material to a cool material through a wall that separates the two materials. HEAT EXCHANGERS IN A PROCESS PLANT NOTE: This manual includes both metric and English units of measurement. If you use English units, disregard the metric units, and vice versa. Refer to the instruction page at the front of the manual. -2- I. TYPES OF EXCHANGERS A. Shell and Tube Exchangers The most common type of heat exchangers used in process plants is a form of shell and tube exchanger. Drawings of such equipment are shown in Figures 1, 2, 3 and 4. Shell and tube exchangers have two obvious major components: 1. A tube bundle, which may contain hundreds of tubes and through which the tube side fluid flows; and 2. A shell that encases the tube bundle and through which the shell side fluid flows. For our purposes, a fluid is a liquid or gas or a mixture of the two. The tube material is usually steel, bronze or aluminum, although stainless steel or other alloys can be used in corrosive or severe tem- perature services. The shell is almost always steel. The inside of a tube usually can be cleaned fairly easily by push- ing a rod through it, or using a high pressure jet on the end of the rod. The outside surface of tubes in an exchanger tube bundle is more diffi- cult to clean, as the surface of many of the tubes is inaccessible. Con- sequently, the fluid that is the most likely to corrode usually flows in- side the tubes. If special material, such as stainless steel, is re- quired to prevent corrosion, only the tubes and channels have to be made of the special material. If the corrosive fluid were to flow in the shell side, the tubes and shell would have to be made of special metal. When water is one of the fluids, the tubes are usually made of a brass alloy called Admiralty, and water flows through the tubes. If both fluids have similar corrosive properties, the stream with the highest pressure usually flows through the tube side. This is be- cause a tube will collapse from an external pressure about one-half the internal pressure that is required to burst the tube. For example, a steel -3- FRONT END REAR END SHEU TYPIS STATIONARY HEAD TYP£5 HEAD TYPES :JfL ｾｾｉｔ＠ T ｾｉ＠ ｉｾ＠ L E A I FIXED TU8ESHEET LIKE "A" STATIONARY HEAD ｾｎｾﾷ＠ ONE PASS SHELL ｾ｢＠ AND REMOVABlf COVER M ｾ＠ e I-i-- I] FIXED TUBESHEET F m ,LIK E "8" STATIONARY HEAD --------- ｣ｃｚｴｩＭＺｾｮ＠ B TWO PASS SHELL N WITH LONGITUDINAL BAFFLE FIXED TUBESHEEf ..... Ｍ ｾ＠ LIKE He' STATIONARY HEAD BONNET (INTEGRAL COVE'!) ｾｉ＠ ------I----- ｉｾ＠ ｾｉｔ＠ Ｎ ｾ＠ G P - - r SPliT flOW OUTSIDE PACKED FLOATING HEAD ］ｾ］ＺＺ ｦｊｴｾ Ｚ］ ［ＺＢ Ｍ］ ］ＬｾｾＬ＠ ｾ＠ｾ＠ '1x ｃｾｾｾｬ｜ｾｨｧｾｾ＠ ｾｉ＠ --i- ｉｾ＠ 5 --i- C m H FLOATING HEAD WITH BACKING DEVICE -- DOUBLE SPLIT FLOW ｾｾＧＺＺｾｽｾｦｴｾｾ＠ FF' T FIXII:O ｾ＠ I ｾ＠ ｾ ｉ＠ I] PUll THROUGH FLOATING HEAD ｾＭＧｃ＠ J ｾ＠ CHANNEL INTEGRAL WlTt1 TUBE- I I ｾ＠ SHEET AND REMOVABLE COVER U ｾ＠ DIVIDED flOW ｾ＠ ｾ＠ U_TUBE BUNDLE " F' I,!.-- ＢＧｦＭＢｦｾ＠ D i.J ｾ＠ ｓＧＺｾ＠ K W Ｇｾｾｾ＠ ·J._iJ SPECIAL HIGH PRESSURE CLOSURE KETTtE TYPE REBOltER PACKWEDIT Hfl OtAATNINnGiN T lUiBNEGS HEE'f Courtesy Tubular Exchanger Mfgrs. Assn. FIGURE 1 TYPES OF SHELL AND TUBE EXCHANGERS -4- 1. Stationary Head-Channel 20. Slip·on Backing Flange 2. Stationary Head-Bonnet 21. Floating Head Cover-External 3. Stationary Head Flange-Channel or Bonnet 22. Floating Tubesheet Skirt 4. Channel Cover 23. Packing Box Flange 5. Stationary Head Nozzle 24. Packing 6. Stationary Tubesheet 25. Packing Follower Ring 7. Tubes 26. Lantern Ring 8. Shell 27. Tie Rods and Spacers 9. Shell Cover 28. Transverse Baffles or Support Plates 10. Shell Flange-Stationary Head End 29. Impingement Baffle 11. Shell Flange-Rear Head End 30. longitudinal Baffle 12. Shell Nozzle 31. Pass Partition 13. Shell Cover Flange 32. Vent Connection 14. Expansion Joint 33. Drain Connection 15. ｆｾｯ｡ｴｩｮｧ＠ Tubesheet 34. Instrument Connection 16. Floating Head Cover 35. Support Saddle 17. Floating Head Flange 36. lifting Lug 18. Floating Head Backing Device 37. Support Bracket 19. Split Shear Ring 38. Weir 39. liquid Level Connection courtesy Tubular Exchanger Mfgrs. Assn. l-PASS SHELL, 2-PASS TUBE EXCHANGER FIGURE 2 HEAT EXCHANGER PARTS