反渗透制取纯水有个特点是:反渗透膜的实际产水量受温度的影响变化较大。大多数实验室超纯水机或反渗透纯水设备产水量是按反渗透膜在25℃进水温度下的标准产水量来标注的。因此,客户在选择实验室超纯水机或反渗透纯水设备时,考虑到冬季水温较低,以及反渗透膜投入使用后水通量会逐渐降低的影响因素,务必放大需求产水量至设备标称产水量的1.5~2倍考虑。
温度对反渗透膜产水量的影响如下图所示。温度变低,水的粘度增加,水的扩散性减弱,产水量也随着温度下降而降低。在同一压力下,温度下降一摄氏度,产水量可减小3~4%。下列方程是产水通量随温度变化的关系。
TCF=exp[K×(1÷(273+t)-1÷298]
其中TCF是温度校正因子,K是膜材料常数,t是进水摄氏温度。该方程将25℃作为基准,TCF=1。
陶氏的FILMTEC反渗透膜温度校正系数(TCF)
温度 ℃ |
温度校 正系数 TCF |
温度 ℃ |
温度校 正系数 TCF |
温度 ℃ |
温度校 正系数 TCF |
温度 ℃ |
温度校 正系数 TCF |
温度 ℃ |
温度校 正系数 TCF |
10 |
1.711 |
14 |
1.475 |
18 |
1.276 |
22 |
1.109 |
26 |
0.971 |
10.1 |
1.705 |
14.1 |
1.469 |
18.1 |
1.272 |
22.1 |
1.105 |
26.1 |
0.968 |
10.2 |
1.698 |
14.2 |
1.464 |
18.2 |
1.267 |
22.2 |
1.101 |
26.2 |
0.965 |
10.3 |
1.692 |
14.3 |
1.459 |
18.3 |
1.262 |
22.3 |
1.097 |
26.3 |
0.962 |
10.4 |
1.686 |
14.4 |
1.453 |
18.4 |
1.258 |
22.4 |
1.093 |
26.4 |
0.959 |
10.5 |
1.679 |
14.5 |
1.448 |
18.5 |
1.254 |
22.5 |
1.09 |
26.5 |
0.957 |
10.6 |
1.673 |
14.6 |
1.443 |
18.6 |
1.249 |
22.6 |
1.086 |
26.6 |
0.954 |
10.7 |
1.667 |
14.7 |
1.437 |
18.7 |
1.245 |
22.7 |
1.082 |
26.7 |
0.951 |
10.8 |
1.66 |
14.8 |
1.432 |
18.8 |
1.24 |
22.8 |
1.078 |
26.8 |
0.948 |
10.9 |
1.654 |
14.9 |
1.427 |
18.9 |
1.236 |
22.9 |
1.075 |
26.9 |
0.945 |
11 |
1.648 |
15 |
1.422 |
19 |
1.232 |
23 |
1.071 |
27 |
0.943 |
11.1 |
1.642 |
15.1 |
1.417 |
19.1 |
1.227 |
23.1 |
1.067 |
27.1 |
0.94 |
11.2 |
1.636 |
15.2 |
1.411 |
19.2 |
1.223 |
23.2 |
1.064 |
27.2 |
0.937 |
11.3 |
1.63 |
15.3 |
1.406 |
19.3 |
1.219 |
23.3 |
1.06 |
27.3 |
0.934 |
11.4 |
1.624 |
15.4 |
1.401 |
19.4 |
1.214 |
23.4 |
1.056 |
27.4 |
0.932 |
11.5 |
1.618 |
15.5 |
1.396 |
19.5 |
1.21 |
23.5 |
1.053 |
27.5 |
0.929 |
11.6 |
1.611 |
15.6 |
1.391 |
19.6 |
1.206 |
23.6 |
1.049 |
27.6 |
0.926 |
11.7 |
1.605 |
15.7 |
1.386 |
19.7 |
1.201 |
23.7 |
1.045 |
27.7 |
0.924 |
11.8 |
1.6 |
15.8 |
1.381 |
19.8 |
1.197 |
23.8 |
1.042 |
27.8 |
0.921 |
11.9 |
1.594 |
15.9 |
1.376 |
19.9 |
1.193 |
23.9 |
1.038 |
27.9 |
0.918 |
12 |
1.588 |
16 |
1.371 |
20 |
1.189 |
24 |
1.035 |
28 |
0.915 |
12.1 |
1.582 |
16.1 |
1.366 |
20.1 |
1.185 |
24.1 |
1.031 |
28.1 |
0.913 |
12.2 |
1.576 |
16.2 |
1.361 |
20.2 |
1.18 |
24.2 |
1.028 |
28.2 |
0.91 |
12.3 |
1.57 |
16.3 |
1.356 |
20.3 |
1.176 |
24.3 |
1.024 |
28.3 |
0.908 |
12.4 |
1.564 |
16.4 |
1.351 |
20.4 |
1.172 |
24.4 |
1.021 |
28.4 |
0.905 |
12.5 |
1.558 |
16.5 |
1.347 |
20.5 |
1.168 |
24.5 |
1.017 |
28.5 |
0.902 |
12.6 |
1.553 |
16.6 |
1.342 |
20.6 |
1.164 |
24.6 |
1.014 |
28.6 |
0.9 |
12.7 |
1.547 |
16.7 |
1.337 |
20.7 |
1.16 |
24.7 |
1.01 |
28.7 |
0.897 |
12.8 |
1.541 |
16.8 |
1.332 |
20.8 |
1.156 |
24.8 |
1.007 |
28.8 |
0.894 |
12.9 |
1.536 |
16.9 |
1.327 |
20.9 |
1.152 |
24.9 |
1.003 |
29.9 |
0.892 |
13 |
1.53 |
17 |
1.323 |
21 |
1.148 |
25 |
1 |
29 |
0.889 |
13.1 |
1.524 |
17.1 |
1.318 |
21.1 |
1.144 |
25.1 |
0.997 |
29.1 |
0.887 |
13.2 |
1.519 |
17.2 |
1.313 |
21.2 |
1.14 |
25.2 |
0.994 |
29.2 |
0.884 |
13.3 |
1.513 |
17.3 |
1.308 |
21.3 |
1.136 |
25.3 |
0.991 |
29.3 |
0.882 |
13.4 |
1.508 |
17.4 |
1.304 |
21.4 |
1.132 |
25.4 |
0.988 |
29.4 |
0.879 |
13.5 |
1.502 |
17.5 |
1.299 |
21.5 |
1.128 |
25.5 |
0.985 |
29.5 |
0.877 |
13.6 |
1.496 |
17.6 |
1.294 |
21.6 |
1.124 |
25.6 |
0.982 |
29.6 |
0.874 |
13.7 |
1.491 |
17.7 |
1.29 |
21.7 |
1.12 |
25.7 |
0.979 |
29.7 |
0.871 |
13.8 |
1.486 |
17.8 |
1.285 |
21.8 |
1.116 |
25.8 |
0.977 |
29.8 |
0.869 |
13.9 |
1.48 |
17.9 |
1.281 |
21.9 |
1.112 |
25.9 |
0.974 |
29.9 |
0.866 |
校正后流量=实测流量×对应于进水温度的温度校正系数(TCF值)。 |