Tek-Tips is the largest IT community on the Internet today!
Members share and learn making Tek-Tips Forums the best source of peer-reviewed technical information on the Internet!
-
Congratulations cowski on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!
the retention time of oil in Buffer tank? 4
- Thread starter ProEngr
- Start date
-
1
- #2
djack77494
Chemical
You'll need to be more specific in your question. Are you trying to provide sufficient residence time to allow water droplets to "fall" out of the oil phase? Time to allow oil droplets to rise out of the aqueous phase? Residence time for control purposes, etc.? We need to know in order to provide an intelligable response.
Doug
Doug
- Thread starter
- #3
- Thread starter
- #4
Google "Stokes flow"
Going the Big Inch!![[worm]](/data/assets/smilies/worm.gif "[worm] [worm]")
Going the Big Inch!
-
1
- #6
-
1
- #7
(1) assume droplets are 100 microns = droplet rise velocity of 0.10 cm/sec = 0.003 ft/sec
(2) 0.003 ft/sec = 0.003 cf/sf-sec = 1.2 gpm/sf =1600 gpd/sf
(3) Provide minimum of 0.8 sf of water surface area for every 1600 gpd of flow
(4) Use 2.0 sf/gpd to allow for turbulence and poor flow distribution
(5) Increase area if you need to size for smaller droplets.
(6) Put a beaker of the water on your desk, observe how well a 3" layer clarifies in one minute. Estimate the rise rate from this test. 70% clarification = rise rate of 2"/min = 0.003 ft/sec.
(2) 0.003 ft/sec = 0.003 cf/sf-sec = 1.2 gpm/sf =1600 gpd/sf
(3) Provide minimum of 0.8 sf of water surface area for every 1600 gpd of flow
(4) Use 2.0 sf/gpd to allow for turbulence and poor flow distribution
(5) Increase area if you need to size for smaller droplets.
(6) Put a beaker of the water on your desk, observe how well a 3" layer clarifies in one minute. Estimate the rise rate from this test. 70% clarification = rise rate of 2"/min = 0.003 ft/sec.
-
1
- #8
As I understand the vessel is already there, so are known flow rates, temperatures, densities, viscosities, interfacial tension, etc.
The (non-identified) oil's hold time will depend on:
(a) as indicated above, the "separation" zone holdup volume but also on
(b) the volume of the supernatant oil phase between its high and low levels (alarms?), i.e. the expected operating surge volume range, which will depend on the processing purpose of the buffer tank.
I suggest you consult books on liquid-liquid separation to estimate (a), and tell us something about (b) to enable contributing some thoughts.
- Thread starter
- #10
- Status
Similar threads
- Question
- Locked
- Question