Adjustable Dip Pipe in Pressurised Vessel

[malc_t7]

Hi All
I'm working on a process design that involves settling a suspension in a vessel, and removal of the supernatant above the settled bed. The settled bed volume varies batch-to-batch, and as much of the supernatant as possible needs to be removed before moving to the next step. The proposal is to have an adjustable dip tube that can be manually lowered to just above the bed, and use a pump to draw off the supernatant. However, finding a design for an adjustable dip tube that can be fitted to a pressurised vessel, and maintaining the pressure rating of the vessel is proving difficult. Does anyone have any recommendations, or experience with a similar requirement?
Thanks.

 

[LittleInch]

Why not use a floating suction arm instead?
Problem with a dip tube is surely that it will suck up some of the bed material when it starts flowing?

Then when it touches the bottom layer it just stops.

How variable in depth is the layer?