API standard

API std 421

API std 421

Published December 10, 2019 10:24 by Henrique Coltraro, WT Business Development Manager at IONFREE

Note that API standards ...

Note that API standards don't mention coalescing filters, to increase particle size or dosing of emulsion breaking chemicals. 

And: there are no real standards for DAF. You have to consider HRT, flow, load, coagulation and flocculation chemicals, internal recirculation of treated water for air saturation, max. air flow without bubble formation etc.

Published December 4, 2019 23:37 by Gerd Teunissen, technical director at INTERAGUA, Lda.

API design parameters(From ...

API design parameters

(From SIEMENS)

Some of the most important design criteria developed for API separators include:

• Length to width ratio. A minimum length to width ratio of 5:1 is recommended for all API separator designs to keep operating conditions as close to plug flow as possible, minimizing the potential for short circuiting.
• Depth to width ratio. A minimum depth to width ratio of 0.3 to 0.5 is recommended so that separation units are not excessively deep, minimizing the amount of time it takes for oil particles to rise to the surface.
• Maximum channel width and depth. The maximum API separator channel width is 20 ft; maximum depth is 8 ft.
• Horizontal velocity. Maintaining a horizontal velocity of no more than 3.0 ft/sec has been shown to minimize turbulence and its effect on interfering with the separation of oil from wastewater.
• Inlet distribution. To minimize the effect of high wastewater inlet velocities into the API separator, and possible short circuiting associated with these high velocities, reaction jet baffles are recommended to diffuse influent flows across the width and depth of the API separator.
• Oil particle size. Majority of oil particles in most refinery wastewaters are 150 micron in size or larger. Therefore, the design standards for API separators were developed for the removal of oil particles of this size. Particles smaller than 150 micron will normally exit an API separator and will need to be removed by downstream treatment processes, unless allowances are made in the sizing of the API separator to remove these smaller particles.

Published December 4, 2019 18:59 by Gerd Teunissen, technical director at INTERAGUA, Lda.

Hello Hasan, I only know ...

Hello Hasan,

I only know this as I design the covers and extraction systems for the odour control side of things. 

The manual that you are after if I understand your question is the API Manual on Disposal of Refinery Wastes, 1st Ed published in 1969. Chapters 5 & 6 covers separators and Chapter 9 covers DAF Units. 

You would need to approach the American Petroleum Institute directly to purchase a copy of the manual.

Regards

Gary Slenders

Principal Process Engineer - AOMC Pty Ltd

Published December 2, 2019 23:01 by Gary Slenders, Principal Process Engineer

would you mind to identify ...

would you mind to identify yourself?

Published November 26, 2019 18:08 by Gerd Teunissen, technical director at INTERAGUA, Lda.

Hello Hasan, You can write ...

Hello Hasan,

You can write an email to my colleague atorrent@sigmadafclarifiers.com explaining your question. We are a company specialized in DAF, CAF and water oil separators so I think we can help you with this topic.

If you want to explore more about us, our webpage is: https://www.sigmadafclarifiers.com/en

Thank you,

Jordi

Published November 26, 2019 09:14 by Jordi Fàbregas Garriga, Water Treatment Specialist