The operation of primary cooler in workshop in Shanxi Coking Co., Ltd can not meet
the demand of production for its bad heat exchange efficiency. There are many slime
sediment and the sediment deterioration products in primary cooler that Purally Water
has the cleaning for their four machines. The results as follows:
The on-line cleaning for every primary cooler (total 4 sets) has following phrases: loop-
in,water flushing, alkaline wash, displacement, slime peeling, displacement ,acid cleaning,
displacement and passivation, etc.
1. Device inspection after cleaning
Microorganism, organic matter and bio-slime on the surface of the device have already
been cleaned. There are no corrosion products in pipes, with the sooty metallic color on
the surface which shows the good passivaiton effect.
2.the cooling effect for primary cooler
The cooling effect has been improved after cleaning by primary cooler. The temperature
of 3£££¬4££ primary coolers decrease from 47¡æ to 36¡æ. The temperature of 1£££¬2££ is
28¡æ before cleaning that it decreases to 26¡æ.
3.the amount of corrosion products after cleaning
The corrosion products and scales can be accounted by iron and hardness detection.
|
Primary cooler |
1 |
2 |
3 |
4 |
total |
|
Corrosion product£¨by Fe2O3£©ton |
1.22 |
1.76 |
1.59 |
2.14 |
6.71 |
|
Hard scale£¨by CaCO3£©ton |
0.74 |
0.51 |
0.62 |
0.43 |
2.30 |
4.Corrosion monitoring in cleaning process
corrosion rate data of testing sheet
|
Primary Cooler |
1 |
2 |
3 |
4 |
|
Cleaning period/h |
7 |
7 |
11.5 |
8 |
|
Average corrosion rate£¨g/m2¡¤h£© |
1.33 |
2.2 |
5£®41 |
5.63 |
|
control index |
Carbon steel test sheet¡Ü6.00g/m2¡¤h |
|
Operation & corrosion condition |
Little corrosion in carbon steel test sheet | |
