【Daily Question No. 350】December 22, 2018
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【Daily Question No. 350】December 22, 2018: Briefly describe the methods for determining tube coking. (1) With the feed remaining unchanged, check whether the pressure difference between the inlet and outlet of the furnace tube increases; if there is any change, the reasons should be analyzed promptly. (2) The furnace outlet temperature drops, and it is difficult to raise the temperature even by increasing the fuel supply. (3) Check whether the surface of the furnace tubes is red; due to coking inside the tubes, the thermal resistance increases, preventing heat from spreading, which causes the local temperature of the tube walls to rise and leads to reddening of those walls. (Unless otherwise specified, all questions and answers are based on hydrogenation units.) ) Correct: 3 wealth, Incorrect: 1 wealth ； Mass posting of posts – rated based on the lowest score ； Replies that are unrelated to the answer are considered spam and will be deleted immediately. For management purposes, if you need to view content from a few days ago, please go to https://bbs.hcbbs.com/home.php?mod=space&uid=3862647&do=thread&view=me&from=space through the summary post below
(1) With the feed remaining unchanged, check whether the pressure difference between the inlet and outlet of the furnace tube increases; if there is any change, the reasons should be analyzed promptly. (2) The furnace outlet temperature drops, and it is difficult to raise the temperature even by increasing the fuel supply. (3) Check whether the surface of the furnace tubes is red; due to coking inside the tubes, the thermal resistance increases, preventing heat from spreading, which causes the local temperature of the tube walls to rise and leads to reddening of those walls.
1. Compare to see if there is any change in the feed pressure of the furnace tube. 2. There is a large temperature difference at the furnace tube outlet. 3. After prolonged coking of the furnace tubes, red spots appear on their surface.
1) The pressure difference at the furnace outlet increases, causing the furnace pressure to rise. 2) The furnace outlet thermocouple indicates a low reading, with slow response. 3) With unchanged operating conditions, the furnace temperature rises significantly, while the outlet temperature fails to increase. 4) The furnace tubes gradually change from pink to black, and even develop peeling and spots; the refractory brick hangers in the furnace chamber change from a warm red color to white. 5) Increased fuel consumption.
With the feed remaining unchanged, check whether the pressure difference between the inlet and outlet of the furnace tube increases; if there is such a change, the reasons should be analyzed promptly.
⑵Dark red spots or stripes appear； ⑶The furnace feed pressure increases at the same processing volume ； ⑷The furnace temperature rises at the same processing volume ； ⑸Fuel consumption increases at the same processing volume ； ⑹In severe cases, the furnace tubes bulge, bend, or perforate ； ⑺The slow response of the furnace outlet temperature indicates coking at the thermocouple sheath.
(1) With the feed remaining unchanged, check whether the pressure difference between the inlet and outlet of the furnace tube increases; if there is any change, analyze the reasons promptly
(1) With the feed remaining unchanged, check whether the pressure difference between the inlet and outlet of the furnace tube increases; if there is any change, the reasons should be analyzed promptly.
As the fuel gas volume increases, the pressure difference increases
1) The pressure difference at the furnace inlet and outlet increases, and the pressure entering the furnace rises. 2) The furnace outlet thermocouple indicates a low reading, with slow response. 3) With unchanged operating conditions, the furnace temperature rises significantly, while the outlet temperature fails to increase. 4) The furnace tubes gradually change from pink to black, and even develop peeling and spots; the refractory brick hangers in the furnace chamber change from a warm red color to white. 5) Increased fuel consumption.
⑴Put on the protective equipment； ⑵Dark red spots or stripes appear ； ⑶The furnace feed pressure increases at the same processing volume ； ⑷The furnace temperature rises at the same processing volume ； ⑸Fuel consumption increases at the same processing volume ； ⑹In severe cases, the furnace tubes bulge, bend, or perforate ； ⑺The slow response of the furnace outlet temperature indicates coking at the thermocouple sheath.