@ LittleInch
Yes you are right, I was thining that the valve is correcting the % opening based on the pressure upstream but this is a consequence of the set pressure downstream. I will correclty install the PT downstream.
@ pierreick
"I cannot believe that 100kg/h of N2 can affect the VOC...
Thanks everyone!
@ georgeverghese
I located the PIC on the liquor tank because I need to know the pressure upstream the valve to know how to regulate in order to keep the pressure downstream with valve DP. But it is also true that I have a pressure transmitter in the filter so the pressure is...
Yesterday I received new information.
The vents are all conveyed to the VOC cryo unit with a compressor. The issues with the cryo unit are both the pressure (main issue) and flow rate (not critical according to what they say).
The filter dryer is not really operated as a batch as they told me at...
Thanks to everybody.
I personally have no experience with cryo units. Most of our clients have thermal oxydizers so high pressure streams in vents have never been a problem. This is the first time that a client comes up with this issue...
@ LittleInch
The problem with the control loop is that I still have to define a flow rate which is impossible for me to calculate, it should be just assumed and maybe not in a correct way (as Snickster basically said too). 100 kg/h is not the correct flow rate in my opinion. See my previous...
@georgeverghese
Thanks! Just a question: how have you defined the 250 mbarg value for PIC control?
The problem is that I have no idea of what is the normal flow rate. I can assume that the liquor tank is filled in say 5 minutes and in this case the flow rate would be very low approx. 7 kg/h...
@LittleInch
Here a few answers:
- 100 kg/h is the max flow rate of the inlet nitrogen line to the filter, but now i do not think it is a reasonable value to consider for the vent from the tank since they operate the machine as a batch.
- design pressure of the liquor tank is 6 barg (protected...
@ Snickster
It seems basically the same control loop, but made on flow rate. Why do you say this is simpler?
Thanks for the interesting link!
@ georgeverghese
The solution you are proposing would be applicable for continuous systems, but in my case the filter dryer is operated as a batch, so...
Hi all,
Nitrogen is supplied to the filter by self operated reducing valve and a shut-off valve is installed in the line. My understanding from client's description is that they are having this issue only towards the end of the liquid separation phase. Note that for other existing filter dryers...
The liquid drain is DN40. Liquor tank is about 500 liters. The 1" vent line is the vent from thr liquor tank which collects thr vents during liquid sepration phase and it is connected to the existing vent (in all conditions, not only if a crack develops). 110 mbar is the pressure drop in this...
@Snickster
Correct, the vent during the squeezing phase flows only from the liquor tank (not from the filter itself) because the system is operated as a batch, so the steps are:
- the filter is filled and pressurized with nitrogen (with all the system closed)
- the liquid discharge valve is...
Hi Shvet,
This is what I have been told from my instrumental department.
Moreover, I do not think it would be the best option because if I consider 2 barg as sizing pressure, the control vale would not start closing before 2 barg, hence I would still have a high pressure stream if I had nitrogen...
My Client (a chemical production plant) has an issue with the vents from filter dryer mother liquor tank. During the solid/liquid separation they operate the filter dryer with nitrogen at 2 barg and collect the liquid in the tank. At the end of the process a crack may form in the filter cake...
