Dry quenching furnace maintenance issues
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There are more and more dry quenching units nowadays, and they generally need to be overhauled once a year. The dry quenching unit in our plant underwent major repairs in March this year, after 4 years of operation. During its shutdown process, there is a cooling curve; how is this curve determined, and what is the basis for it? I request that everyone provide relevant information; thank you........................
The temperature reduction is based on T5 (the preset section temperature), and it is recorded at the corresponding point on the curve every half hour; any deviation should be corrected promptly. The temperature drop is slight. During the coking removal process, it is necessary to closely monitor the temperature to ensure that it remains below 230 ℃. Criteria for ending cooling down ； The temperature near T5 and various manholes reaches around 50 °C ； Samples of the circulating gas are taken at the roof vent for testing, and it is considered qualified if it meets the specified standards:
The cooling should be primarily at T6 temperature
Start the cooling process. Step 1: From 1000℃ to 400℃ – the cooling rate is controlled by adjusting the volume of circulating air, the amount of nitrogen introduced, and intermittent coke removal. ⑴Introduce air and close all the middle plugs. (But the opening of the middle valve must be determined based on the gas composition within the circulation system and the boiler inlet temperature.) ⑵ The pressure in the storage section is controlled at 100 Pa---150 Pa using heat-resistant butterfly valves. ⑶The preset section pressure control valve and the circulating gas return valve should be manually closed completely. ⑷Open the nitrogen filling valves at the inlet, outlet, and discharge device of the circulating fan. ⑸When the amount of nitrogen filled in is changed, the pressure in the storage section also changes; in such cases, a valve should be used for adjustment. ⑹When the cooling rate is too fast, that is, when T5>17°C/H or T5>11.5°C/H, the following methods can be employed for adjustment. ①, gradually reduce the circulating air volume ； ②Reduce the amount of nitrogen filled in ； ③Stop the discharge of coke. ⑺When the cooling rate is too slow, that is, at T54.8°C/H, the following methods can be used for adjustment. ①, gradually reduce the circulating air volume ； ②Slowly reduce the air intake volume. ⑺, when the cooling rate is too slow, that is, T5