Freezing problem of instrument steam tracing in chemical plants during winter
Thread Content
In our factory, temperatures can drop to -40 degrees or even -50 degrees in winter. It’s difficult to maintain the steam heating for instruments; if the heating is interrupted for even a short period of time, freezing occurs immediately. What is the appropriate way to handle the instrument at this time? Especially some differential pressure transmitters whose medium is water. How should it be handled?
There is no other way; use steam heating and add an isolation fluid
Having been involved in instrument design for many years, I rarely choose instruments that use pressure transfer tubes, considering factors such as cost-performance and installation/maintenance. So, heat tracing and insulation become much more convenient. A suitable design choice can reduce a lot of maintenance work
If steam tracing is not effective, consider using electric tracing. Medium water contains a certain amount of heat, so it shouldn’t freeze that quickly; if the system is parked for an extended period, the liquid has to be drained.
Our devices, such as waste boilers, generate steam; level transmitters cannot use capillaries – we are currently using differential pressure types with pressure guiding tubes. The temperature is a bit high. What other types of transmitters can be used? ? ?
1 Forms and methods of insulation and heating 2 Installation of insulation and heating systems 3 Selection of drain valves 4 Application examples of insulation and heating 5 Conclusions ① Steam heating is suitable for media that tend to crystallize or are viscous. ②Insulated heating pipelines should be kept at a certain distance from the instrument measurement pipelines used for liquid media, or effective isolation measures should be taken to prevent the liquid from vaporizing and causing errors in measurements. ③Electric tracing is generally used for heating and insulating instruments that are located far from steam sources. ④In the cold regions of the north, in the absence of special requirements, steam heating is the most suitable heating method for production needs compared to electric heating and hot water heating. ⑤Generally, electric heat tracing belts cannot be used together with steam heating; if they are used together, proper isolation measures must be taken.
First, open the steam trap to drain as much water as possible from the heat tracing tubes and pressure tapping pipes. Water cannot be drained from areas where there are bends, but try to remove it as much as possible. Otherwise, if it freezes for an extended period of time, the heat tracing tubes may crack.
Steam tracing is a real hassle in winter! It’s more convenient to use electric heating! If it’s frozen, thaw it! Hot air guns, pouring boiling water, and the like! There are no good solutions!
At such low temperatures, when there is a disruption in the heating supply, it is necessary to immediately drain the condensate from the heating pipelines, switch control to manual mode, stop the meter, and empty the liquid from the pressure guiding pipes. Once normal operation is restored, the system can be put back into use – this approach helps to minimize losses and prevents any significant damage!
The emergency plan we have drafted for now is more or less like this; thank you. .
This post was last edited by dsjce on 2012-3-12 at 21:42. Regarding the unstable heating you mentioned, it is recommended to use electric heating to prevent the instruments from being damaged by freezing; the typical minimum operating temperature for such instruments is minus 20 degrees Celsius