The tar tank does not heat up despite heating

First, check whether there is a problem with the thermometer by observing the liquid level at the upper part of the tank. Next, consider whether the groove has been in use for a long time, resulting in an accumulation of tar residue at the bottom that affects the heating area.

It is the heat transfer coefficient of the heat exchanger and its heat transfer area that determine the heat transfer temperature difference.

The initial wash is used to determine whether the temperature is accurate; as mentioned on the 2nd floor, the actual temperature at the site should be measured to see if it matches the temperature indicated by the original thermometer. Then consider whether to start a new project, ruling out design issues. Whether the size and quantity of the coils are sufficient, whether the size and specifications of the mixer are appropriate, and the insulation condition of the tank ； Is the tar feed temperature meeting the design requirements? ； Is the tar mixer operating properly? Consider on-site issues again. As mentioned on the second floor, it is necessary to check whether there is coking at the bottom of the tank, whether the feed temperature is below the designed value, whether the insulation is damaged, whether the temperature and pressure of the steam are normal, and whether the drainage of steam condensate is unobstructed (if the condensate cannot be drained, it will affect the heat exchange process and prevent the temperature from rising).

Could it be that the liquid at the temperature measurement point is not moving, resulting in inaccurate temperature readings?

This post was last edited by lupg on 2019-2-10 at 10:36. 1. Analysis from the perspective of heat balance: 1.1. Heat input = Heat loss, maintaining a constant temperature. 1.2. Heat input > Heat loss, resulting in an increase in the temperature of the medium being heated. 1.3. Heat input < Heat loss, resulting in a decrease in the temperature of the medium being heated. 2. Using these basic relationships to analyze temperature changes: 2.1. There may be a shortage of steam, as the poster only provided information on pressure but not on flow rate. 2.2. The oil tank has a large volume, leading to high heat loss. 3. Temperature can rise during the initial stages of heating: 3.1. This is because, at the beginning of heating, there is a large temperature difference between the steam and the medium, resulting in efficient heat transfer. 3.2. The surface temperature of the oil tank is low, resulting in a smaller temperature difference and thus less heat loss. 3.3. As heating continues, the situations described in 3.1 and 3.2 reverse; heat transfer becomes less efficient while heat loss increases, until equilibrium is reached and the temperature remains constant

Based on observations, it is likely caused by excessive slag accumulation at the bottom of the tank

Thank you to all the teachers for their guidance and help.