3 replies to this topic

[somen]

Hi,

Based on sulfur plant capacity, we are designing a sulfur storage tank of 30 m dia and 12 m height. Considering molten sulfur behaviour and large size of the tank, I would like to know if it is recommended to have the tank bottoms sloped towards centre which is generally followed for storage tanks.

Regards,

Somen

[Art Montemayor]

Somen:

It has always been my preference to have ALL storage tanks' floors sloped.

But that is only my preference. Sloped floors are extra capital costs and to succeed in obtaining a tank with a sloped floor you have to have economic and/or operational reasons that will make it possible. It winds up with you having to have a strong grasp of your operational, safety, and economic means. If you can come up with strong and positive operational and maintenance reasons for demanding sloped floors, then you should openly declare them. You should also develop an accurate cost adder required for the sloped construction.

We can do all the recommending you need or require, but ultimately you have to justify and backup the need for a sloped floor. Don't forget the safety factor involved in being able to positively drain the tank and reducing the amount and risk of human entry into the confined space due to the positive drain.

I hope this experience helps out.

[fallah]

Hi,

Based on sulfur plant capacity, we are designing a sulfur storage tank of 30 m dia and 12 m height. Considering molten sulfur behaviour and large size of the tank, I would like to know if it is recommended to have the tank bottoms sloped towards centre which is generally followed for storage tanks.

Regards,

Somen

For same cases 2 percent slope have been recommended.

[kkala]

Having seen only pits of molten sulphur, I would share few theoretical thoughts.
1. API-650 tank bottoms, either bottom-up or bottom-down, are designed with a slope of usually 2%. These are tanks for petroleum and other products (e.g. water). Fallah, can you advise whether the reported 2% slope concerns tanks in general or specifically sulphur tanks? "Drain" may not be needed in molten sulphur tanks.
2. Molten sulphur is clearly a different product, so I would search for the applicable practice. Construction of such tank may require a different practice/code to API 650. Besides there are issues of maintaining uniform temperature, controlling corrosion (is it refinery sulphur?), firefighting, etc. Some chemical engineering guides are at http://www.sulphuric...hur/storage.htm.
3. http://ncsp.tamu.edu...eports 1868.htm indicates sulphur bottom-down tank of higher slope, but apparently this was a much smaller tank than the one required.

Edited by kkala, 26 November 2010 - 12:25 PM.