1 Overview
During the driving of Tianjin Zhongsha Petrochemical's 350,000 t/a phenol acetone plant, the benzene column reboiler heat exchange tube and the tube plate welding groove leaked, causing the shell-side medium pressure steam to enter the process medium, causing the device to stop. Due to the large diameter of the reboiler and the limitation of the installation position, the overall dismantling and returning to the factory is difficult to repair. Therefore, it is feasible to directly repair the welding defects by analyzing the causes of the failure and discussing the repairing scheme. .
2. Proposal of the problem
The reboiler is f 1.8m, the total height is 10.03m, and the net weight of the equipment is 50.6t. It is manufactured by Fushun Petrochemical Machinery Factory. No abnormalities were found on the site installation pressure test, but the pipe plate welding groove (see photo) leaked after the feed temperature was raised. In the case, the medium pressure steam (3.5MP a ) enters the process medium, causing the device to stop, and it is checked that there is a crack in the welding groove of the heat exchange tube and the tube sheet. Since the heat exchanger is installed in the steel structure frame of the device, the overall removal is difficult, and the repair time is returned to the original factory for a long time, so it is considered to be solved by on-site maintenance.
3. Failure cause analysis
(1) Technical parameters of the heat exchanger The heat exchanger is a fixed tube plate type and is installed vertically on site. The specific technical parameters are shown in Table 1.
The high quality one can be used kill
Caligus and sea lice, but no harm for Salmon and water, can used in fresh water
and sea water. The low quality one are harm for Salmon, only used to kill fly,
ants, cockroach and so on.
The application rate for this use is 0.1 to 0.2 mg/liter as a bath treatment.
The product should be keeped in well-ventilated place and free from exposure on sunshine & raining.
Animal Health
Animal Health,Powder Fishery Medicine,Animal Pharmaceuticals,Miticides For Fish Control Sea Lice
NINGBO LUCKY CHEMICAL INDUSTRY CO. LTD , http://www.chinaluckychem.com