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Usmankulov Alisher Kadirkulovich, DSc., doctor of science in technical Sadikov Farkhod Samandarovich, senior lecturer, Djizakh Polytechnic Institute E-mail: daminov.asror86@gmail.com
RESEARCH TEPLOFIZICHESKY PROPERTIES OF THE CLAP-RAW AND ITS COMPONENTS
Abstract: A preparation the basis comparative analysis the productivity of equipment various methods. Keywords: coefficient of useful time, clap-raw, fibers, clamping device, formulas, speed, drying, productivity.
As is known, cotton-the raw unlike firm bodies, possesses hygroscopic and porous colloidal properties [1]. In the humidified condition and at thermal influence inside of a clap of raw kinds molecular and molar carry of a moisture and heat are possible all. Process of carry of heat in damp porous bodies is connected with process of carry of a moisture which inside of a body can be both in the form of a liquid, and in the form of pair. Thus of pairs in times is in rubbed also molecular balance with a liquid and consequently process can be considered evaporation as steam formation in the big vessel. Known scientific and applied works [1; 2] do not allow to receive satisfactory enough thermal and hygroscopic pair-meters a clap-raw. Therefore there was an imperative need in development of the techniques allowing objectively estimating parameters of a clap.
In the given work results experimental effort changes of a thermal capacity of a clap-raw and its components in dependence from temperature and humidity are resulted. Measurement of a thermal capacity was spent in vacuum-pneumatic a calorimeter with discrete input [3]. The copper tight calorimeter in volume of10 sm-3 is used. An error of definition of a thermal capacity in an interval of temperatures 30-1500 oC no more than 0.5. Thus, however, measure -NO not a true thermal capacity, and an average thermal capacity on a temperature interval AT.
C= AQ/AT
AQ The final quantity of heat brought to the sample
(Dj), AT = T2 -T -
The final increment of temperature caused by it about T1 and T2 -
Temperature of the sample before heating; This value of a thermal capacity carry to average temperature Tsr = (T + T2)/2
Temperature of the sample before heating; This value of a thermal capacity carry to average temperature (kg).
C = C obraztsa / m
At measurements the specific thermal capacity of the sample is defined:
C = Cn - C0 / m
Co the Cn -
Thermal capacity of the filled calorimeter (Dj/kg • K),-heat capacity an empty calorimeter (Dj/K).
Technique of carrying out of experiment following: the-calorimeter is filled with known object on weight (cotton-seed, a cotton-fiber, seeds, etc.), and weighed on analytical weights; the-calorimeter is located under a vacuum cap and is made from-rolling in current of 10-20 minutes. After eviction a calorimeter again -NO on analytical weights if within the limits of exactness analytical weights - that the calorimeter is considered change of a lump tight. Further measurement of a thermal capacity on standard techniques is made.
In figure 1-3 curves experimental fibers (fig. 2) and the lowered seeds (fig. 3) from temperature are presented is dependent to a specific thermal capacity of a clap-raw (fig. 1), at different wet. To the dependence show, that in an interval of change of temperature.
In drawing 1-3 curves of experimental dependences of a specific thermal capacity of a clap-raw (fig. 1), fibers (fig. 2) and the lowered seeds (fig. 3) from temperature are presented at different wet. The received dependences show, that in the range of change of temperature 300 C < T < 100 0 C the thermal capacity of a clap of a raw and a fiber increases linearly, and at temperature from above 100 oC it sharply increases, that is connected with change of their structural properties at heats. It is necessary to notice, that in difference from known references [1; 2], change of a specific thermal capacity of a clap-raw in a temperature interval 20-90 With makes an order of 15%, and in the range of 20-150 With - more 45%.
Let's enter density of a clap of a raw and its components (a fiber, the lowered seeds) in the modular condition, defined under formulas
Pax = miPl + m2p2 + m4p4 , Pax = miPl + m3p3 + m4 P4
where p1, p2, P3 and p4 - True density of air, fiber, seeds and water; m1, m2, m3 and m4 - according to their concentration in unit shares, and m1 + m2 + m3 + m4 = 1 For a raw clap, m1 + m2 + m4 = 1 for fiber, m1 + m3 + m4 = 1 for seeds.
On T > 100 0 C Size m4 will correspond concentration of water as a part of steam.
350034003300320031003000 29002800270026002500 2400 2300 2200 21002000 1900180017001600-
O CD Œ CD O -i—' CD CD
As experiences were spent at constant density of a clap of a raw and its components in modular condition pax = 110kg / m3, pav = 76kg / m3, pas = 76kg / m3 to temperature and humidity change there is under different laws a redistribution of concentration of air mx, fibers m2, seeds m3 u of water m4 as a part of a clap of a raw and its components.
-8% —•— -24%
-T—T -A- -36%
—t— -45%
▲-A-
20 40
60
~1— 80
100
120
140
°C
temperature
Drawing 1. Dependence of a thermal capacity of a clap-raw on temperature at different (humidity in%; thermal capacity Dj/kg)
o ra
ra o
ra 0
3200-, 3100 3000 2900 280027002600 2500 24002300 2200 2100 2000 190018001700 1600 150014001300 1200
-7% -17% -38.9% -56.6%
___ ▼-▼ A
▼ T . A ^ ^
•-•
300 320 340 360 380 400
temperature
420
Drawing 2. Dependence of a thermal capacity of a cotton fibre on temperature at different moisture (humidity in%; thermal capacity Dj/kg)
o
2900280027002600-& 2500-to 2400-to 2300" 2200-<u 2100-^ 2000190018001700160015001400-
▲-A
-0% -10% -20% -30%
•—•
20
40
~i— 60
80
temperature
100
120
140
Drawing 3. Dependence of a thermal capacity of the lowered seeds on temperature at various temporize (humidity in, thermal capacity Dj/kg)
This can explain significant change of behavior of curves near to a point where water completely turns in pairs. It is necessary to note also, that the condition of thermodynamic balance comes after end internal теплообменных processes, about differently in a clap a raw and its components. It circumstance, on visible leads to essential difference from each other curves dependences of a thermal capacity of a clap of a raw and its components on themes and humidity. The analysis of these curves shows, that dependence of a thermal capacity on temperature practically submits linear, or is more exact to the square-law law. In this connection experimental curves for thermal capacities a damp clap-raw, a fiber and seeds all over again we shall present by means of the general dependence [4] Cp = aT2 + bT + c , (1) where a, b и c - the constants depending on humidity u and defined from an extreme функционал of a square-law deviation
S = X(y, - aT2 - bT - cY, i= 1
Where y-, - skilled values of a thermal capacity at temperature for the fixed humidity of a material, N - quantity of experimental points. The relative divergence of skilled data of a thermal capacity with its values calculated under the formula (l) was estimated under the formula
|y. - aT2 - bT- - c 1100% A- =Vi-:---1-
i yi
Practical application of the formula (l) causes inconvenience as factors a, b u c implicitly depend on humidity u. Therefore we enter the formula containing obvious dependence of a thermal capacity from humidity. Dependence (l) we will present in a kind
C = (k2u + klu + k0)(a *T + bT + c*),
(2)
Table 1. Comparison of skilled data of change of a thermal capacity cotton -a raw from temperature at various values of humidity with results of calculations under formulas
o
а* =-0.0130, b* = 8.561, c* = 1817.86, k2 = 0, kt = 0.01207, k0 = 0.68
W = 8% a = -0.0234, b = 9.3221, c = 1351.81 W = 24% a = -0.0332, b = 11.06, c = 1624.85
Т °C Experiment Formulas^) Pogr. A (%) i Formulas (2) Pogr. A (%) i Experiment Formulas (1) Pogr. A (%) i Formulas (2) Pogr. A (%) i
1 2 3 4 5 6 7 8 9 10 11
30 1632 1610 1.323 1602 1.835 1912 1926 0.771 2000 4.625
40 1691 1687 0.223 1661 1.747 2047 2014 1.608 2074 1.350
50 1742 1759 0.997 1718 1.329 2101 2095 0.294 2146 2.156
60 1800 1826 1.491 1774 1.433 2152 2169 0.786 2215 0.161
70 1871 1889 0.994 1827 2.321 2219 2236 0.783 2282 0.303
1 2 3 4 5 6 7 8 9 10 11
80 1961 1947 0.678 1878 4.187 2289 2297 0.358 2346 0.121
90 2006 2001 0.243 1928 3.880 2340 2351 0.101 2466 0.280
100 2071 2050 1.022 1975 4.611 2401 2399 0.086 2466 0.112
110 2103 2094 0.434 2021 3.910 2464 2440 0.980 2523 1.623
120 2140 2133 0.316 2064 3.550 2483 2474 0.357 2577 4.768
130 2164 2167 0.181 2105 2.715 2499 2502 0.111 2628 5.194
140 2184 2231 0.636 2144 1.811 2511 2522 0.469 2677 6.641
W = 36% W = 45%
a = 0.0277, b = 1.202, c = 2178.02 a = -0.0231, b = 12.662, c = 2116.77
To C Experiment Formulas^) Pogr. A (%) i Formulas (2) Pogr. A (%) i Experiment Formulas (1) Pogr. A (%) ' Formulas (2) Pogr. A (%) '
30 2225 2239 0.629 2299 3.337 2517 2476 1.635 2523 0.252
40 2273 2270 0.114 2384 4.906 2595 2586 0.337 2616 0.845
50 2310 2307 0.114 2467 6.791 2673 2692 0.713 2707 1.284
60 2355 2349 0.218 2546 8.125 2762 2793 1.139 2794 1.178
70 2411 2397 0.544 2623 8.789 2850 2890 1.395 2878 1.002
80 2483 2451 1.270 2696 8.602 2944 2981 1.280 2959 0.524
90 2499 2510 0.463 2767 10.74 3022 3068 1.554 3037 0.499
100 2543 2575 1.267 2835 11.49 3229 3151 2.396 3111 3.636
110 2638 2645 0.281 2900 9.939 3324 3229 2.838 3182 4.245
120 2719 2721 0.079 2962 8.947 3329 3303 0.779 3251 2.343
130 2798 2802 0.158 3021 7.985 3348 3371 0.712 3316 0.957
140 2906 2889 0.577 3077 5.909 3387 3435 1.446 3378 0.274
Table 2. Comparison of skilled data of change of a thermal capacity of a fiber from temperature at various values of humidity with results of calculations under formulas (1) and (2)
a, = 0.0406, b. = -0.7894, c, = 1894.28, k2 = - 0.003, k, = 0.0287, k0 = 0.5178
3 II 7 Xp W = 17.6%
a = 0.0335, b = -0.8156, c = 1310.19 a = 0.0365, b = 1.375, c = 1593.16
To C Experiment Formulas^) Pogr. A, (%) i Formulas (2) Pogr. A, (%) i Experiment Formulas (1) Pogr. A. (%) ' Formulas (2) Pogr. a, (%) '
1 2 3 4 5 6 7 8 9 10 11
30 1295 1315 1.611 1342 3.680 1673 1667 0.339 1773 6.017
40 1330 1331 0.085 1357 2.039 1721 1707 0.833 1792 4.171
50 1365 1353 0.871 1377 0.903 1787 1753 1.884 1819 1.816
60 1400 1382 1.301 1403 0.231 1798 1807 0.516 1853 3.098
70 1435 1417 1.243 1435 0 1832 1868 1.996 1895 3.465
80 1479 1459 1.337 1472 0.457 1867 1937 3.757 1944 4.168
90 1501 1508 0.465 1515 0.954 1912 2013 5.285 2001 4.694
100 1509 1563 3.607 1564 3.653 2201 2096 4.758 2066 6.122
110 1620 1625 0.345 1619 0.082 2269 2186 3.623 2138 5.761
120 1697 1694 0.150 1679 1.065 2331 2284 1.989 2217 4.853
130 1779 1769 0.506 1745 1.917 2379 2389 0.452 2305 3.109
140 1862 1852 0.524 1817 2.439 2443 2502 2.424 2400 1.771
W = 38.9%, W = 56.75%,
a = 0.0401, b = -1.1413, c = 2221.32 a = 0.0524, b = -2.576, c = 2452.47
To C Experiment Formulas (1) Pogr. A (%) ' Formulas (2) Pogr. A (%) ' Experiment Formulas (1) Pogr. A (%) ' Formulas (2) Pogr. A (%) '
1 2 3 4 5 6 7 8 9 10 11
30 2210 2223 0.595 2251 1.854 2419 2422 0.141 2251 6.938
40 2235 2239 0.214 2275 1.801 2442 2433 0.353 2275 6.821
50 2276 2264 0.508 2309 1.454 2470 2455 0.614 2309 6.507
60 2314 2297 0.730 2352 1.666 2500 2487 0.528 2352 5.891
70 2353 2337 0.656 2405 2.235 2529 2529 0 2405 4.872
80 2398 2386 0.480 2468 2.929 2549 2582 1.300 2468 3.161
90 2432 2443 0.456 2540 4.460 2593 2645 2.028 2541 2.018
100 2479 2508 1.166 2622 5.780 2630 2719 3.403 2622 0.286
110 2502 2580 2.833 2713 8.462 2929 2804 4.270 2714 7.343
120 2739 2661 3.143 2814 2.765 2971 2900 2.429 2815 5.252
130 2780 2750 1.073 2925 5.228 3015 3004 0.357 2926 2.966
140 2821 2846 0.920 3045 7.959 3054 3120 2.165 3045 0.269
Table 3. - Comparison of skilled data of change of a thermal capacity lowered cotton-growing from temperature at various values of humidity with results of calculations under formulas (1) and (2)
a, = 0.0242, b, = 8.468, c, = 1709.95, k2 = 0, k, = 0.016, k0 = 0.75
W = 0% W = 10%
a = -0.0211, b = 7.787, c = 1188.44 a = -0.0285, b = 9.341, c = 1507.74
To C Experiment Formulas^) Pogr. A, (%) ' Formulas (2) Pogr. A, (%) ' Experiment Formulas (1) Pogr. A. (%) ' Formulas (2) Pogr. a, (%) '
1 2 3 4 5 6 7 8 9 10 11
30 1415 1402 0.886 1456 2.945 1777 1762 0.826 1767 0.538
40 1465 1465 0.023 1507 2.900 1835 1835 0.042 1829 0.322
50 1515 1524 0.594 1554 2.619 1891 1903 0.663 1886 0.246
60 1575 1578 0.219 1598 1.476 1955 1965 0.543 1939 0.808
70 1625 1629 0.225 1638 0.811 2010 2021 0.596 1987 1.111
80 1685 1674 0.613 1674 0.623 2101 2072 1.348 2032 3.297
90 1645 1716 4.342 1707 3.779 2075 2117 2.055 2071 0.175
100 1800 1753 2.556 1736 3.542 2187 2157 1.375 2106 3.675
110 1819 1787 1.741 1762 3.152 2205 2190 0.657 2138 3.062
120 1828 1816 0.633 1783 2.436 2225 2218 0.297 2163 2.744
130 1834 1841 0.397 1801 1.764 2235 2240 0.249 2185 2.193
140 1845 1862 0.918 1816 1.561 2247 2257 0.447 2203 1.929
W = 20% W = 30%
a = -0.0254, b = 8.823, c = 1883.34 a = 0.0181, b = -7.075, c = 2284.86
To C Experiment Formulas (1) Pogr. A, (%) ' Formulas (2) Pogr. A, (%) ' Experiment Formulas (1) Pogr. a, (%) ' Formulas (2) Pogr. A, (%) '
30 2139 2125 0.647 2078 2.843 2495 2480 0.567 2389 4.205
40 2200 2196 0.199 2150 2.241 2540 2539 0.041 2472 2.666
50 2251 2261 0.443 2218 1.465 2585 2593 0.326 2549 1.366
60 2301 2321 0.880 2280 0.905 2630 2644 0.544 2687 0.337
70 2368 2376 0.358 2337 1.303 2680 2692 0.432 2746 0.247
80 2417 2427 0.397 2389 1.161 2730 2735 0.191 2679 0.592
90 2485 2472 0.537 2436 1.989 2780 2775 0.170 2800 0.711
1 2 3 4 5 6 7 8 9 10 11
100 2533 2512 0.834 2477 2.210 2831 2812 0.628 2847 0.580
110 2556 2546 0.371 2513 1.670 2856 2844 0.402 2889 1.160
120 2577 2576 0.026 2544 1.264 2877 2874 0.115 2924 1.664
130 2592 2601 0.349 2570 0.836 2894 2899 0.182 2954 2.097
140 2615 2621 0.218 2591 0.914 2912 2921 0.317 2978 2.285
In tables 1-3 values of constants a, b, c., a*, b*, c*, k2,kl, k0 And the given thermal capacities depending on the temperature, received by practical consideration and results of calculations under formulas (l) and (2) for times-personal values of humidity are presented. From data follows, (2) value of a constant is practically equal the formula to zero that will be coordinate with the formula offered in work [1]. Close to each other values have factors and at different BAa^Hocrax separately for a clap of a raw and its components, and factors, and have near values only for a clap of a raw and seeds (tab. 1 and 3), that specifies the general character of change of their thermal capacity from temperature and its moisture.
Conclusions
1. The experimental technique of measurement of a thermal capacity of a cotton-raw and its components depending on temperature and humidity is developed.
2. By the analysis of experimental data it is established, at constant density of a clap of a raw and its components, occurs redistribution concentration of air and a moisture in their structure which can influence to a course of curve dependences of a thermal capacity from temperature and humidity
3. Empirical formulas for calculation of a thermal capacity of a clap-raw and its components, approximating experimental dependence are offered by linear or square-law functions.
References:
1. Shchekoldin M. I. Thermo moist constants of a raw-cotton.- M. Gizleprom, 1958.
2. Lykov A. V. Theor of drying.- M, "Energy", 1968.
3. Shashkov A. G. Method of measurements thermo moist characteristics of materials.- Minsk. 1996.- 136c.
4. Usmankulov A. K. Analytical researches warmly in a two-layer sphere at convection to drying. Samarkand, 2007 the International conference «Modern problems of mechanics».- P. 79-84.
