4 replies to this topic

[123sm]

Eductor is installed in Tank for homogenous/intimate mixing of liquid having high viscousity. The application is mainly limited to fixed roof tank.
Has anybody come across the eductor installed in Internal Floating Roof Tank (IFR)

[ankur2061]

Eductor is installed in Tank for homogenous/intimate mixing of liquid having high viscousity. The application is mainly limited to fixed roof tank.
Has anybody come across the eductor installed in Internal Floating Roof Tank (IFR)

123sm,

What is the link between the type of tank roof & eductor (also known as jet mixer)? Eductor as you yourself mention is for homogeneous/intimate mixing. Also eductors are designed for liquid submergence.

I simply fail to see the connection of roof type & eductor. Where did you get the information about eductors only being installed for fixed roof tanks?

Regards,
Ankur.

[123sm]

Eductor is installed in Tank for homogenous/intimate mixing of liquid having high viscousity. The application is mainly limited to fixed roof tank.
Has anybody come across the eductor installed in Internal Floating Roof Tank (IFR)

123sm,

What is the link between the type of tank roof & eductor (also known as jet mixer)? Eductor as you yourself mention is for homogeneous/intimate mixing. Also eductors are designed for liquid submergence.

I simply fail to see the connection of roof type & eductor. Where did you get the information about eductors only being installed for fixed roof tanks?

Regards,
Ankur.

Ankur,
Let me explain the concern.In the internal Floating Roof Tank the movable roof will travel across the dia of tank i.e from top to bottom as the liquid levels falls.Therfore when liquid level decreases the floating roof will also gradually comes at the bottom .Now say when the liquid level is at bottom , at that moment doesn't eductor comes in the way of floating roof ( fouling with floating roof).I don't know whether it is acceptable or not.
Now as we know the use of floating roof in tank will minimise the generated flammable gas vol. over the stored liquid.But in case of inductor installed in such tank the travel of floating roof to be limited to certain level to avoid fouling with eductor nozzle and thus allowing generation of flammable gas mixture over the stored liquid.Is that accetable and also whether eductor opeartion is safe at that moment(at low liquid level of tank).This is the concern.If it is still unclear pls. let me know.

[ankur2061]

Ankur,
Let me explain the concern.In the internal Floating Roof Tank the movable roof will travel across the dia of tank i.e from top to bottom as the liquid levels falls.Therfore when liquid level decreases the floating roof will also gradually comes at the bottom .Now say when the liquid level is at bottom , at that moment doesn't eductor comes in the way of floating roof ( fouling with floating roof).I don't know whether it is acceptable or not.
Now as we know the use of floating roof in tank will minimise the generated flammable gas vol. over the stored liquid.But in case of inductor installed in such tank the travel of floating roof to be limited to certain level to avoid fouling with eductor nozzle and thus allowing generation of flammable gas mixture over the stored liquid.Is that accetable and also whether eductor opeartion is safe at that moment(at low liquid level of tank).This is the concern.If it is still unclear pls. let me know.

!23sm,

The eductor or jet mixer is supposed to be installed at the lowest possible point of the tank liquid level so that a free jet of liquid does not impinge on the walls of the tank. It simply defeats the purpose of the eductor if the operating liquid level falls below the eductor nozzle.

So, in principle you are never supposed to allow the tank level to fall below the eductor connection. Hence the concern that roof will foul with the eductor nozzle seems to be misplaced.

Another thing is that if the stored liquid has a low vapor pressure & is very viscous you seriously need to evalauate whether you need a floating roof tank. Floating roof tanks cost a lot of money in comparison to fixed roof tanks.

Hope this helps.

Regards,
Ankur.

[Qalander (Chem)]

Ankur,
Let me explain the concern.In the internal Floating Roof Tank the movable roof will travel across the dia of tank i.e from top to bottom as the liquid levels falls.Therfore when liquid level decreases the floating roof will also gradually comes at the bottom .Now say when the liquid level is at bottom , at that moment doesn't eductor comes in the way of floating roof ( fouling with floating roof).I don't know whether it is acceptable or not.
Now as we know the use of floating roof in tank will minimise the generated flammable gas vol. over the stored liquid.But in case of inductor installed in such tank the travel of floating roof to be limited to certain level to avoid fouling with eductor nozzle and thus allowing generation of flammable gas mixture over the stored liquid.Is that accetable and also whether eductor opeartion is safe at that moment(at low liquid level of tank).This is the concern.If it is still unclear pls. let me know.

!23sm,

The eductor or jet mixer is supposed to be installed at the lowest possible point of the tank liquid level so that a free jet of liquid does not impinge on the walls of the tank. It simply defeats the purpose of the eductor if the operating liquid level falls below the eductor nozzle.

So, in principle you are never supposed to allow the tank level to fall below the eductor connection. Hence the concern that roof will foul with the eductor nozzle seems to be misplaced.

Another thing is that if the stored liquid has a low vapor pressure & is very viscous you seriously need to evalauate whether you need a floating roof tank. Floating roof tanks cost a lot of money in comparison to fixed roof tanks.

Hope this helps.

Regards,
Ankur.

Dear 123sm Hello/Good Morning,

Definitely you have already received 'good' & 'great' guidance on your quary from our friend ankur.

I will like to alert you that the designing stage is the correct point to address and ensure

any jetmixing nozzle's positioning grade level wise, its adequacy

the available sufficient liquid level in the storage tank under discussion; prior to jet nozzle initial start/ regular operation in-service

at all times having it fully immersed to safeguard against hazardous static charges generation,accumulation possibilities.

Few other important ponts are

to have the nozzle fully bonded/ grounded with low resistant metal,

its tip exact vertical orientation ensured;such that the roof does not get any rotation torque induced by the jet.

Hope this proves helpful.