Process Automation Requirements Specifications

Pharmaceutical Fermenters

2011-05-22T10:10:00.000-07:00

I have recently been looking at ControlDraw models for large scale Pharmaceutical Fermenter Units from 4 different companies. All are broadly similar
I cannot publish them because because they are confidential, agreements signed!

However I have summarised them using some statistics from the models. (Click to enlarge)

Some differences are immediately apparent.

Why is the IO Count for Client 3 so low? This is because they do not use limit switches on their valves. This is something I have never understood as it seems to me that any cost savings would be obliterated by the downtime cause by the inablity to quickly diagnose valve failures.

Why do Clients 1 and 3 have so many parameters? I think that this is in part because they do not distinguish between critical parameters (that can be changed to define the product or CIP ) and other parameters

Storage and Mixing Vessel - with em's and phases

2010-08-13T11:48:00.000-07:00

Responding to the initial version on the Process Automation Modelling LinkedIn Group, we have

LinkedIn Groups

Group: Process Automation Modelling
Subject: New comment (1) on "A combined storage and mixing vessel"

I think the design is flexible and not unique. See my quick idea as below:

(Physical Level)
Unit: UNIT (TK101)
EM: EQM01 (XV911, XV912, XV913, XV914), EQM02 (XV101, XV102, XV103), EQM03 (XV104, XV105, XV106, P102)
CM: VALVE (XV101-XV106, XV911-XV914), MOTOR (M101, P102), TRANSMITTER (WT101, TT104), DI (LSL102)

(Procedure Level)
Phase: AGIT PHASE (agitator), JCKT PHASE (jacket), TXIN PHASE (tank transfer in), TXOT PHASE (tank transfer out), WGHT PHASE (weight)

(Equipment Phase Logic in Controller):
AGIT PHASE: Use agitator on-off command, motoe speed setpoint etc. phase parameters to control M101 start/stop and speed. LSL from WGHT PHASE can interlock the agitator for protecting purpose.

JCKT PHASE: Use Cool, Heat, temperature setpoint etc. phase parameters, and operate EQM01 valves matrix, compare with TT104, to control tank temperature.

TXIN PHASE: Use source route setpoint (eg. 1=Solvent, 2=Upstream1, 3=Upstream2), quantities setpoint etc. phase parameters and operate EQM02 valves matrix, compare with WT101, to transfer liquid into tank.

TXOT PHASE: Use destination route setpoint (eg. 1=Down Stream, 2=Drain), quantities setpoint etc. phase parameters and operate EQM03 valves matrix, compare with WT101, to transfer material out from tank. LSL from WGHT PHASE can also interlock the P102 for protecting purpose.

WGHT PHASE: Use LSL setpoint, density setpoint etc. phase parameters to monitor level and generating LSL alarm message etc.

I think for process engineer, it will be easy to combine these phases and create the different type recipes.

Yuping
Here is a diagram with the equipment modules and phases shown

Storage and Mixing Vessel

2010-08-11T03:53:00.000-07:00

This vessel can be used for several different liquids, one at a time.
It can also be used to blend different liquids.
The Vessel Receives liquid from an upstream source, which may be a tanker delivery or an upstream vessel
If then Delivers liquid downstream
It can stores the liquid at a controlled temperature, This may be above or below ambient depending on the liquid
The liquid is stirred, but the rate of stirring should ensure that energy is not wasted, by stopping the agitator or varying the speed.

Receiving can take place at the same time as delivering downstream, but this is not normally the case.
It is an Operator decision whether to all this.

The downstream process takes the material in batches, and there may be several downstream demands. These together may exceed the capacity of the discharge pump, so an arbitration system is required.

The vessel must be flushed with solvent to prevent cross contamination of different liquids.

The URS Writer Web

2009-07-14T16:51:00.000-07:00

URSWriter.com is about Defining User and Functional Requirements for Process Manufacturing

It is intended to help people to write good specifications. And over the couple of years that it has been on the web it has been improved when I get time.

The web site has some unobtrusive advertising – if you are wondering, at present this just about covers the cost of the hosting and of course adds a few dollars to Google profits. And it also generates some interesting resources for further exploring the topic.

Welcome readers

2009-07-14T16:24:00.000-07:00

This is a place for YOUR comments. Please let us know.

How do you write them?

What software do you use?

What processes are you specifying?

And to comment on the URS Writer website so that it may be improved