服務(wù)熱線: 400 886 8302
一、泵類型的確定
泵的類型主要由工作所需的氣量、真空度或排氣壓力而定。
泵工作時(shí),需要注意以下兩個(gè)方面:
根據(jù)以上原則,當(dāng)泵所需的真空度或氣體壓力不高時(shí),可優(yōu)先在單級(jí)泵中選取。如果真空度或排氣壓力較高,單級(jí)泵往往不能滿足,或者,要求泵在較高真空度情況下仍有較大氣量,即要求性能曲線在較高真空度時(shí)較平坦,可選用兩級(jí)泵。如果真空度要求在-710mmHg以上,可選用水環(huán)-大氣泵或水環(huán)-羅茨真空機(jī)組作為抽真空裝置。
二、根據(jù)系統(tǒng)所需的氣量選擇真空泵
初步選定了泵的類型之后,對(duì)于真空泵,還要根據(jù)系統(tǒng)所需的氣量來選用泵的型號(hào)。
關(guān)于真空泵的抽速選擇及抽氣時(shí)間計(jì)算可參照我公司網(wǎng)頁 真空計(jì)算公式。
面對(duì)各種型式的水環(huán)式真空泵及壓縮機(jī),我們特將其各自特點(diǎn)收集如下,以利于用戶選型
三、水環(huán)真空泵的水溫對(duì)其性能影響較大,而水環(huán)真空泵的性能曲線均為在15℃的水溫條件下測得,因此在實(shí)際選用水環(huán)真空泵時(shí)應(yīng)對(duì)水環(huán)真空泵的抽氣速率進(jìn)行修正。
水環(huán)泵的實(shí)際抽速可根據(jù)Qt=Q15K,K=(P1-Pt)/(P1-P15)計(jì)算修正值,其中:
Qt-水溫為t℃時(shí)的氣量m3/min Q15-水溫為15℃時(shí)的氣量m3/min
P1-水環(huán)泵的吸入壓力mmHg Pt-水溫為t℃時(shí)的飽和蒸汽壓力mmHg
P15-水溫為15℃時(shí)的飽和蒸汽壓力mmHg K-氣量修正系數(shù)
水環(huán)真空泵在各種溫度及吸入壓力下的K值可參照下表
水溫 |
吸入壓力 mmHg |
||||||||||||||||
25 |
30 |
35 |
40 |
50 |
60 |
80 |
100 |
120 |
150 |
200 |
250 |
300 |
400 |
500 |
600 |
760 |
|
0 |
1.685 |
1.486 |
1.376 |
1.307 |
1.225 |
1.177 |
1.124 |
1.096 |
1.078 |
1.061 |
1.045 |
1.035 |
1.029 |
1.022 |
1.017 |
1.014 |
1.011 |
2 |
1.627 |
1.445 |
1.345 |
1.281 |
1.206 |
1.162 |
1.114 |
1.088 |
1.071 |
1.056 |
1.041 |
1.032 |
1.027 |
1.02 |
1.016 |
1.013 |
1.01 |
4 |
1.561 |
1.398 |
1.308 |
1.252 |
1.184 |
1.145 |
1.102 |
1.079 |
1.064 |
1.05 |
1.037 |
1.029 |
1.024 |
1.018 |
1.014 |
1.012 |
1.009 |
6 |
1.487 |
1.345 |
1.268 |
1.218 |
1.16 |
1.126 |
1.088 |
1.068 |
1.055 |
1.043 |
1.032 |
1.025 |
1.021 |
1.015 |
1.012 |
1.01 |
1.008 |
8 |
1.403 |
1.286 |
1.221 |
1.181 |
1.132 |
1.104 |
1.073 |
1.056 |
1.046 |
1.036 |
1.026 |
1.021 |
1.017 |
1.013 |
1.01 |
1.008 |
1.007 |
10 |
1.308 |
1.219 |
1.169 |
1.138 |
1.101 |
1.08 |
1.056 |
1.043 |
1.035 |
1.027 |
1.02 |
1.016 |
1.013 |
1.01 |
1.008 |
1.006 |
1.005 |
12 |
1.201 |
1.143 |
1.111 |
1.09 |
1.066 |
1.052 |
1.037 |
1.028 |
1.023 |
1.018 |
1.013 |
1.01 |
1.009 |
1.006 |
1.005 |
1.004 |
1.003 |
14 |
1.081 |
1.057 |
1.045 |
1.036 |
1.027 |
1.021 |
1.015 |
1.011 |
1.009 |
1.007 |
1.005 |
1.004 |
1.003 |
1.003 |
1.002 |
1.002 |
1.001 |
16 |
0.946 |
0.962 |
0.97 |
0.976 |
0.982 |
0.986 |
0.99 |
0.992 |
0.994 |
0.995 |
0.996 |
0.997 |
0.998 |
0.998 |
0.999 |
0.999 |
0.999 |
18 |
0.795 |
0.855 |
0.888 |
0.908 |
0.933 |
0.947 |
0.963 |
0.971 |
0.977 |
0.982 |
0.987 |
0.989 |
0.991 |
0.994 |
0.995 |
0.996 |
0.997 |
20 |
0.627 |
0.735 |
0.795 |
0.833 |
0.878 |
0.904 |
0.932 |
0.948 |
0.958 |
0.967 |
0.976 |
0.981 |
0.984 |
0.988 |
0.991 |
0.992 |
0.994 |
21 |
0.536 |
0.671 |
0.745 |
0.792 |
0.848 |
0.88 |
0.916 |
0.935 |
0.947 |
0.959 |
0.97 |
0.976 |
0.98 |
0.985 |
0.988 |
0.99 |
0.992 |
22 |
0.439 |
0.602 |
0.692 |
0.748 |
0.816 |
0.855 |
0.898 |
0.922 |
0.936 |
0.95 |
0.963 |
0.971 |
0.976 |
0.982 |
0.986 |
0.988 |
0.991 |
23 |
0.337 |
0.53 |
0.636 |
0.703 |
0.783 |
0.829 |
0.88 |
0.907 |
0.925 |
0.941 |
0.957 |
0.966 |
0.972 |
0.979 |
0.983 |
0.986 |
0.989 |
24 |
0.23 |
0.454 |
0.577 |
0.655 |
0.747 |
0.801 |
0.86 |
0.892 |
0.912 |
0.932 |
0.95 |
0.96 |
0.967 |
0.976 |
0.981 |
0.984 |
0.987 |
25 |
0.117 |
0.374 |
0.515 |
0.604 |
0.71 |
0.772 |
0.84 |
0.876 |
0.899 |
0.921 |
0.942 |
0.955 |
0.962 |
0.972 |
0.978 |
0.982 |
0.986 |
26 |
0 |
0.289 |
0.449 |
0.55 |
0.671 |
0.741 |
0.818 |
0.86 |
0.886 |
0.911 |
0.935 |
0.948 |
0.957 |
0.968 |
0.975 |
0.979 |
0.984 |
27 |
- |
0.2 |
0.38 |
0.494 |
0.63 |
0.708 |
0.795 |
0.842 |
0.872 |
0.9 |
0.926 |
0.942 |
0.952 |
0.964 |
0.972 |
0.977 |
0.982 |
28 |
- |
0.106 |
0.308 |
0.435 |
0.587 |
0.674 |
0.771 |
0.824 |
0.857 |
0.888 |
0.918 |
0.935 |
0.946 |
0.96 |
0.968 |
0.974 |
0.979 |
29 |
- |
0.008 |
0.231 |
0.372 |
0.541 |
0.638 |
0.746 |
0.804 |
0.841 |
0.876 |
0.909 |
0.928 |
0.941 |
0.956 |
0.965 |
0.971 |
0.977 |
30 |
- |
- |
0.151 |
0.307 |
0.493 |
0.601 |
0.719 |
0.784 |
0.824 |
0.863 |
0.899 |
0.921 |
0.934 |
0.951 |
0.961 |
0.968 |
0.975 |
31 |
- |
- |
0.066 |
0.238 |
0.443 |
0.561 |
0.692 |
0.762 |
0.807 |
0.849 |
0.889 |
0.913 |
0.928 |
0.946 |
0.957 |
0.965 |
0.972 |
32 |
- |
- |
- |
0.166 |
0.39 |
0.519 |
0.662 |
0.74 |
0.788 |
0.835 |
0.879 |
0.904 |
0.921 |
0.941 |
0.953 |
0.961 |
0.97 |
33 |
- |
- |
- |
0.089 |
0.334 |
0.475 |
0.631 |
0.716 |
0.769 |
0.819 |
0.868 |
0.896 |
0.914 |
0.936 |
0.949 |
0.958 |
0.967 |
34 |
- |
- |
- |
0.01 |
0.276 |
0.429 |
0.599 |
0.691 |
0.749 |
0.804 |
0.856 |
0.886 |
0.906 |
0.93 |
0.945 |
0.954 |
0.964 |
35 |
- |
- |
- |
- |
0.215 |
0.381 |
0.565 |
0.665 |
0.727 |
0.787 |
0.844 |
0.877 |
0.898 |
0.925 |
0.94 |
0.95 |
0.961 |
36 |
- |
- |
- |
- |
0.15 |
0.33 |
0.53 |
0.637 |
0.705 |
0.77 |
0.831 |
0.867 |
0.89 |
0.918 |
0.935 |
0.946 |
0.958 |
38 |
- |
- |
- |
- |
0.012 |
0.221 |
0.453 |
0.579 |
0.657 |
0.732 |
0.804 |
0.845 |
0.872 |
0.905 |
0.925 |
0.937 |
0.951 |
40 |
- |
- |
- |
- |
- |
0.102 |
0.369 |
0.514 |
0.605 |
0.691 |
0.774 |
0.821 |
0.852 |
0.891 |
0.913 |
0.928 |
0.943 |
42 |
- |
- |
- |
- |
- |
- |
0.277 |
0.443 |
0.547 |
0.646 |
0.74 |
0.795 |
0.831 |
0.875 |
0.9 |
0.917 |
0.935 |
45 |
- |
- |
- |
- |
- |
- |
0.122 |
0.324 |
0.45 |
0.57 |
0.685 |
0.751 |
0.795 |
0.848 |
0.879 |
0.9 |
0.921 |
50 |
- |
- |
- |
- |
- |
- |
- |
0.086 |
0.257 |
0.419 |
0.574 |
0.664 |
0.723 |
0.794 |
0.836 |
0.864 |
0.893 |
55 |
- |
- |
- |
- |
- |
- |
- |
- |
0.018 |
0.233 |
0.438 |
0.556 |
0.634 |
0.728 |
0.784 |
0.821 |
0.859 |
60 |
- |
- |
- |
- |
- |
- |
- |
- |
- |
0.004 |
0.27 |
0.424 |
0.524 |
0.647 |
0.72 |
0.767 |
0.817 |
70 |
- |
- |
- |
- |
- |
- |
- |
- |
- |
- |
-0.18 |
0.068 |
0.23 |
0.429 |
0.546 |
0.624 |
0.704 |
80 |
- |
- |
- |
- |
- |
- |
- |
- |
- |
- |
- |
- |
- |
0.115 |
0.297 |
0.417 |
0.542 |
100 |
- |
- |
- |
- |
- |
- |
- |
- |
- |