The article is focused on definition of optimum parameters of the pyrolitic unit basic module
heating with respect to specified operating conditions. Suitable available fuel gases are propane and
natural gas. The total capacity of torches is 200 kW. All energetic values has been calculated and
reconciled for the both gases with respect to significant factors influencing the heating process
course. In the conclusion the established values are summarized and evaluated.Příspěvek je zaměřen na určení optimálních parametrů ohřívání základního modulu pyrolýzní
jednotky vzhledem k požadovaným podmínkám provozu. Jako vhodné topné plyny jsou k dispozici
propan a zemní plyn. Celkový výkon hořáků činí 200 kW. Veškeré energetické veličiny jsou
vypočteny a srovnány pro oba plyny, a to z podstatných hledisek ovlivňujících průběh spalovacího
procesu. V závěru příspěvku je shrnutí a vyhodnocení zjištěných hodnot

Honus, Stanislav

Juchelková, Dagmar

Roubíček, Václav

Transactions of the VŠB - Technical University of Ostrava Mechanical Series

DSpace at VSB Technical University of Ostrava

 99 Transactions of the VŠB – Technical University of Ostrava, Mechanical Series No. 1, 2010, vol. LVI article No. 1749   Stanislav HONUS *, Dagmar JUCHELKOVÁ **, Václav ROUBÍČEK ∗∗∗  DESIGN AND CALCULATION OF HEATING OF PYROLITIC FURNACE BASIC MODULE OF THE PYROMATIC UNIT  NÁVRH A VÝPOČET OHŘÍVÁNÍ ZÁKLADNÍHO MODULU PYROLÝZNÍ PECE JEDNOTKY PYROMATIC  Abstract The article is focused on definition of optimum parameters of the pyrolitic unit basic module heating with respect to specified operating conditions. Suitable available fuel gases are propane and natural gas. The total capacity of torches is 200 kW. All energetic values has been calculated and reconciled for the both gases with respect to significant factors influencing the heating process course. In the conclusion the established values are summarized and evaluated.    Abstrakt Příspěvek je zaměřen na určení optimálních parametrů ohřívání základního modulu pyrolýzní jednotky vzhledem k požadovaným podmínkám provozu. Jako vhodné topné plyny jsou k dispozici propan a zemní plyn. Celkový výkon hořáků činí 200 kW. Veškeré energetické veličiny jsou vypočteny a srovnány pro oba plyny, a to z podstatných hledisek  ovlivňujících průběh spalovacího procesu. V závěru příspěvku je shrnutí a vyhodnocení  zjištěných hodnot.  1 DESCRIPTION OF THE PYROMATIC UNIT AND THE BASIC MODULE  FUNCTION The Pyromatic Unit is the technological facility for processing of organic matters (within the processing range from 50 to 200 kg per hour) without oxidant inlet for the purpose of degrading of these matters and recycling of valuable energetic products without negative environmental impacts.   The facility operation comprises feeding of the input raw material to the reaction chamber, its heating without air and cleaning and cooling of produced pyrolytic gas. It also includes outlet of solid and liquid products. Pyromatic Unit is fully automated. In the course of operation all important pa-rameters are monitored by many measuring elements connected to the control room, where all values are displayed and recorded. In the basic module of the facility – in the retort – the material is disintegrated by heat and in the same time it is moved by two primary crew conveyors and one secondary screw conveyor (that feeds the material back to the retort inlet part). The retort of the total length 4000 mm is made of stainless austenitic steel 253 MA (EN 1.4835). The process temperature ranges from 600°C to 800°C.  The time of the material stay in the retort ranges from 45 minutes to 60 minutes.                                                                                                                                                                      *   Ing., VŠB - Technical University of Ostrava, Faculty of Mechanical Engineering, Department of Power Engineering, Faculty of Mechanical Engineering, VŠB - Technical University of Ostrava, 17. listopadu 15, Ostrava, tel.: +420 597 323 270, e-mail: stanislav.honus@seznam.cz ** prof. Ing., Ph.D., VŠB - Technical University of Ostrava, Faculty of Mechanical Engineering, Department  of Power Engineering, 17. listopadu 15, Ostrava, tel.: +420 597 325 175, e-mail: dagmar.juchelkova@vsb.cz  ***prof. Ing., CSc., Dr.h.c., VŠB - Technical University of Ostrava, Faculty of Metalurgy and materials Engineering, Department of Chemistry, 17. listopadu 15, Ostrava, tel.: +420 597 325 293, email: vaclav.roubicek@vsb.cz   100  Fig. 1: Pyrolitic unit PYROMATIC  Pyrolitic gas generated in the retort goes to a cyclone where it is cleaned of solid impurities and it continues to an air cooler and a water cooler. In the course of gas cooling some hydrocarbons are condensed into liquid faction, the properties of which are determined mainly by the composition of material treated by pyrolisis. After this treatment the gas is either accumulated in the gas holder of directly consumed.   Fig. 2: Retort Set     101  2 RETORT HEATING METHOD AND FUEL GASES CHARACTERISTICS  Heat for the retort heating is delivered by indirect heating by five section of gas torches (S1 through S5) arranged one after another under the retort body. Heating gas is either propane or natural gas for higher throughput. Maximum required thermal input of the furnace is 200 kW that means maximum 40 kW for one section of torches. According to the pyrolisis temperature setting the tem-perature of flue gases ranges from 600°C to 800°C.  Burning air enters individual sections through the hole under the torches and it could be regu-lated either by throttling on the inlet or by revolutions of the flues gas fan.  Tab. 1: Fuel gases properties   Propane Natural gas Calorific value [kJ.m-3N] 93 180 35 870 Combustion heat [kJ.m-3N] 101 205 39 794 Density [kg.m-3N] 2,01 0,73 CH4 - 98,39     CMHN - 0,7 Gas chemical composition  [%] C3H8 - 100     CO2 - 0,07       N2 - 0,84  3 CALCULATION METHOD AND DETERMINATION OF COMBUSTION PROCESS     OPTIMUM CONDITIONS FOR PROPOSED FUEL GASES  Following summary presents formulas necessary for calculation of the fuel gas and combus-tion airs quantities, flow, flue gases composition and other parameters of the combustion process.     Based on the calorific values and required thermal capacity necessary gas flow plV. is deter-mined by the formula:   [ ]13,. −⋅= smQPV Nplipl ,     (1) where: P  – thermal output of torches [kW], Qi,pl  – fuel gas calorific value [kJ.m-3N].  Minimum quantity of dry air s tvzV , necessary for combustion of a fuel gas unit is calculated from the gas composition and oxygen content in the air:   ][5,05,08,3421,01 3322,−⋅−⋅+⋅+⋅+⋅⎟⎠⎞⎜⎝⎛ +Σ⋅= NNNMyxs tvz mmOHCOHCHCyxV ,  (2) where:   CMHN – content of ethylenic hydro carbons in the fuel gas [1], CxHy – content of saturated hydrocarbons in the fuel gas [1], CO  – content of carbon monoxide in the fuel gas [1], H2  – content of hydrogen in the fuel gas [1], O2 – content of oxygen in the fuel gas [1].  102 Value defining the actual quantity of humid air v svzV ,  considers air humidity and the surplus air with direct impact on the flue gases temperature:   ][ 33,, −⋅⋅⋅= NNs tvzv svz mmnVV υ ,    (3) where:  n  – air surplus  [1], υ  – humidity coefficient [1] (set υ = 1,03). Produced dry flue gases s sspV ,  are calculated as a sum of produced carbon dioxide and surplus air:  ( ) ][1 33,, 22 −⋅⋅−++= NNs tvzNCOs ssp mmVnVVV ,    (4) where the carbon dioxide content in the flue gases 2COV is determined by the formula:    ][6,2 3322−⋅⋅+⋅Σ++= NNNMXXCO mmHCHCxCOCOV    (5) and content of nitrogen 2NV  is determined by the formula:   ][79,0 33,22−⋅⋅+= NNs tvzN mmVNV      (6)  Humidity of flue gases  OHV 2  is determined by the formula:   ( ) ][14,2233,22−⋅⋅⋅−+⋅+⋅Σ+= NNs tvzNMyxOH mmnVHCHCyHV ν   (7) and actual content of humid flue gases v sspV , is determined consequently:  ][ 33,, 2−⋅+= NNOHs sspv ssp mmVVV .       (8)  Concentrations of individual factions in the flue gases are expressed as a volume share of re-spective element is proportion to the total volume of humid flue gases:    [%]100,22⋅= vsspCOCO VVω ,      (9) [%]10079,0,,,22⋅⋅⋅+= vsspstvzpalNN VnVVω ,    (10)  ( )[%]100121,0,,2⋅⋅−⋅= vsspstvzO VVnω ,     (11) ]1[100,22⋅= vsspOHOH VVω .      (12)  103 Calculated values allow us to establish flow volume of air .,vsvzV  and flow volume of produced flue gases .,vsspV with respect to the fuel gas flow:  ][ 13.,.,−⋅⋅= smVVV Nplv svzv svz ,     (13)  ][ 13.,.,−⋅⋅= smVVV Nplv sspv ssp .     (14)  Based on the composition and enthalpy the temperature of flue gases spt can be determined using the formula:     ( ) [ ]Cbibaatspspspspspsp °⋅−⋅⋅−±−=242 ,    (15)  Flue gases enthalpy spi  is determined from thermal capacity and flow volume of humid flue gases produced:  ⎥⎦⎤⎢⎣⎡= 3.,Nvsspsp mkJVPi .      (16)  Values of auxiliary coefficients spa  and spb are derived from formulas expressing dependence of the gas enthalpy on the temperature. General formula is as follows:  2tbtai iii ⋅+⋅= ,       (17) for actual gases:  oxygen - 2000141614,032107,12ttiO ⋅+⋅= , nitrogen - 2000108509,028392,12ttiN ⋅+⋅= , carbon dioxide - 2000413123,073614,12ttiCO ⋅+⋅= , and water - 2000250404,047301,12tti OH ⋅+⋅= .  Auxiliary coefficient can be determined from contents of individual gases in the flues gases:   iniiisp aa ω⋅=∑==1,      (18)  iniiisp bb ω⋅=∑==1.      (19)  104 Dependences of relevant resulting values on the air surplus possibly on required thermal capacity of torches are presented in Figures 3, 4 and 5.  Note: All volume units apply for normal conditions.   Dependence of total necessary flows of fuel gases and combustion air on the thermal capacity of all torches0,0000,0010,0020,0030,0040,0050,00650 75 100 125 150 175 200Thermal capacity of all torches  [kW]Total flow volume of fuel gas[m3N/s]0,050,070,090,110,130,150,170,190,210,23Total flow volume of combustion air [m3N/s]Total flow volume of propane[m3N/s]Total flow volume of NG[m3N/s]Total flow volume ofcombustion air (n=4) atcombustion of propane[m3N/s]Total flow volume ofcombustion air (n=4) atcombustion of  NG [m3N/s] Fig. 3: Required flows of combustion air and heating gases with respect to the heating capacity  of torches  Dependence of flue gases temperature and flow volume of air on surplus air 400500600700800900100011002,50 2,75 3,00 3,25 3,50 3,75 4,00 4,25 4,50Surplus air [1]Flue gases temperature [°C]0,030,050,080,100,130,150,180,200,230,250,28Flow volume of combustion air [m3N/sTemperature of propane flue gases [°C]Temperature of NG flue gases [°C]Total flow volume of combustion air atcombustion of propane[m3N/s]Total flow volume of combustion air atcombustion of NG [m3N/s]Air flow volume to Section 1 atcombustion of propane [m3N/s]Air flow volume to Section 1 atcombustion of NG [m3N/s] Fig. 4: Dependence of the flue gases temperature on flow volumes or air and surplus air    105 Dependence of temperature and flow volume of produced flue gases on the air surplus400500600700800900100011002,50 2,75 3,00 3,25 3,50 3,75 4,00 4,25 4,50Air surplus [1]Flue gases temperature  [°C]0,120,140,160,180,200,220,240,26Flow volume of produced flue gases[m3N/s]Temperature of propane flue gases [°C]Temperature of NG flue gases [°C]Total flow volume of produced flue gasat combustion of propane   [m3N/s]Total flow volume of produced flue gasat combustion of NG [m3N/s] Fig. 5: Dependence of the temperature and the flow volume of produced flue gases of the surplus air    4 CONCLUSION AND SUMMARY OF RESULTING VALUES  The objective of presented calculation is to establish optimum conditions of the burning proc-ess in Pyromatic pyrolitic unit furnace for heating either with propane or natural gas.   The calculation established that maximum thermal capacity of torches 200 kW requires the supply of 2,15.10-3 m3N.s-1 of propane or 5,58.10-3 m3N.s-1 of natural gas. With respect to required flue gases temperature ranging from 600°C to 800°C it is necessary to supply combustion air with the surplus of approximately 3,25 to 5,50 for the both gases.   The combustion air flow volume for the surplus 4 and maximum capacity of torches is  0,2105 m3N.s-1  for propane and 0,2182 m3N.s-1 for natural gas.  Summary of all relevant energetic parameters is contained in the following tables.     Tab. 2: Necessary flows of combustion air and flue gases with respect to the thermal output of torches Required thermal output of all torches [kW] 50 75 100 125 150 175 200 Total gas flow volume  [m3N.s-1] 0,00054 0,00080 0,00107 0,00134 0,00161 0,00188 0,00215 Total flow volume of combustion air [m3N.s-1] Pro-pane 0,0526 0,0790 0,1053 0,1316 0,1579 0,1842 0,2105 Total gas flow volume  [m3N.s-1] 0,00139 0,00209 0,00279 0,00348 0,00418 0,00488 0,00558 Total flow volume of combustion air  [m3N.s-1] NG 0,0545 0,0818 0,1091 0,1364 0,1636 0,1909 0,2182 Gas flow volume per one section  [m3N.s-1] 0,00011 0,00016 0,00021 0,00027 0,00032 0,00038 0,00043 Gas flow volume per one section  [lN.min-1] 6,44 9,66 12,88 16,10 19,32 22,54 25,76 Air flow volume per one section  [m3N.s-1] Pro-pane 0,0105 0,0158 0,0211 0,0263 0,0316 0,0368 0,0421 Gas flow volume per one section  [m3N.s-1] 0,00028 0,00042 0,00056 0,00070 0,00084 0,00098 0,00112 Gas flow volume per one section  [lN.min-1] 16,73 25,09 33,45 41,82 50,18 58,54 66,91 Air flow volume per one section  [m3N.s-1] NG 0,0109 0,0164 0,0218 0,0273 0,0327 0,0382 0,0436 Note: Flow volume of combustion air apply for the surplus n = 4.  106 Tab. 3: Combustion process energetic parameters in dependence of the air surplus Note: Flow volumes of air and flue gases are related to maximum thermal capacity of torches that means  one section S1  with the output 40 [kW], all five section S1-5 with the output 200 [kW]. Air surplus [1] 2,50 2,75 3,00 3,25 3,50 3,75 4,00 4,25 4,50 Propane 23,81 Theoretical quan-tity of  dry air[m3N.m-3N] NG 9,50 Propane 61,31 67,44 73,57 79,70 85,83 91,96 98,10 104,23 110,36 Actual quantity of humid air  [m3N.m-3N] NG 24,46 26,90 29,35 31,79 34,24 36,68 39,13 41,57 44,02 Propane 3,00 CO2 content in flue gases  [m3N.m-3N] NG 1,00 Propane 18,81 N2 content in flue gases [m3N.m-3N] NG 7,51 Propane 57,52 63,48 69,43 75,38 81,33 87,29 93,24 99,19 105,14 Actual quantity of dry flue gases [m3N.m-3N] NG 22,76 25,13 27,51 29,88 32,26 34,63 37,01 39,38 41,75 Propane 5,79 5,96 6,14 6,32 6,50 6,68 6,86 7,04 7,21 Humidity in flue gases  [m3N.m-3N] NG 2,70 2,77 2,84 2,91 2,98 3,05 3,12 3,20 3,27 Propane 63,31 69,44 75,57 81,70 87,83 93,96 100,10 106,23 112,36 Actual quantity of humid flue gases [m3N.m-3N] NG 25,46 27,90 30,35 32,79 35,24 37,68 40,13 42,58 45,02 Propane 4,74 4,32 3,97 3,67 3,42 3,19 3,00 2,82 2,67 CO2 concentration in flue gases  [%] NG 3,94 3,59 3,30 3,06 2,85 2,66 2,50 2,36 2,23 Propane 74,28 74,49 74,67 74,82 74,95 75,07 75,17 75,25 75,33 N2 concentration in flue gases  [%] NG 73,71 73,98 74,20 74,38 74,54 74,68 74,81 74,91 75,01 Propane 11,85 12,60 13,23 13,77 14,23 14,63 14,99 15,30 15,58 O2 concentration in flue gases  [%] NG 11,75 12,51 13,14 13,68 14,15 14,55 14,91 15,22 15,50 Propane 9,14 8,59 8,13 7,74 7,40 7,11 6,85 6,62 6,42 H2O concentration in flue gases [%] NG 10,59 9,92 9,36 8,88 8,46 8,10 7,79 7,51 7,26 S1 0,0272 0,0298 0,0324 0,0351 0,0377 0,0403 0,0430 0,0456 0,0482 S1-5 Propane 0,1359 0,1490 0,1622 0,1754 0,1885 0,2017 0,2148 0,2280 0,2412 S1 0,0284 0,0311 0,0338 0,0366 0,0393 0,0420 0,0448 0,0475 0,0502 Flow volume of pro-duced flue gases [m3N.s-1] S1-5 NG 0,1419 0,1556 0,1692 0,1828 0,1965 0,2101 0,2238 0,2374 0,2510 S1 0,0263 0,0290 0,0316 0,0342 0,0368 0,0395 0,0421 0,0447 0,0474 S1-5 Propane 0,1316 0,1448 0,1579 0,1711 0,1842 0,1974 0,2105 0,2237 0,2369 S1 0,0273 0,0300 0,0327 0,0355 0,0382 0,0409 0,0436 0,0464 0,0491 Flow volume of neces-sary air [m3N.s-1] S1-5 NG 0,1364 0,1500 0,1636 0,1773 0,1909 0,2045 0,2182 0,2318 0,2454 Propane 1471,82 1341,87 1233,01 1140,48 1060,87 991,65 930,91 877,18 829,32 Flue gases en-thalpy [kJ.m-3N] NG 1409,07 1285,57 1181,97 1093,83 1017,92 951,86 893,85 842,51 796,75 Propane 1003 924 857 799 748 703 663 628 596 Flue gases tem-perature [°C] NG 965 889 824 769 720 677 639 604 574  107 Acknowledgements The article was prepared in the scheme of the following projects:  2A-3TP1/052 – Research and development of module pyrolitic unit for processing of selected faction of biological waste (MPO) and SP/201092 – Research in the field of pyrolytic processes (specific research).    LITERATURE [1] Blahož, V., Lapčík, V.: Návody do cvičení z termomechaniky, Technical University of Ostrava, 1989 [2] Noskievič, P.: Spalování uhlí, Technical University of Ostrava, 2005 [3] Obroučka, K.: Termické odstraňování a energetické využívání odpadů, Technical University of Ostrava, 2001 [4] Rédr, M.: Základy tepelné techniky, Technical University of Ostrava, 1988         108       

Návrh a výpočet ohřívání základního modulu pyrolýzní pece jednotky Pyromatic

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Návrh a výpočet ohřívání základního modulu pyrolýzní pece jednotky Pyromatic

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