Genzyme Corp. recently installed a multi-bus control system platform at its 12-year-old pharmaceutical facility in Allston, Mass., which manufactures enzyme replacement therapies for rare lysosomal storage disorders (LSDs). The facility originally used a conventional distributed control system to make two enzyme replacement therapies, while the multi-bus control system and new process equipment were installed recently in a renovated suite, which is used exclusively for manufacturing Myozyme, which is a drug therapy for Pompes disease.
This was our first introduction to bus technology at Genzyme and our subsequent selection of bus technologies based on the process equipment needs within a cell culture and protein purification manufacturing environment. Bus technology is used in process areas electrically-rated general purpose and Class 1, Div. 2.
[Fieldbus in Biopharma, Part 1, Control, July 06, focused on why Genzyme decided to use fieldbus, how and where it was deployed, and what architecture was used. Part 2 continues coverage of how Genzymes fieldbus segments were designed.]
More Segment Design
The buses selected for our facility included a powered bus and an unpowered bus. The powered buses include FF and AS-i, while the unpowered buses include Profibus-DP and DeviceNet. The goal was to have the stick-built process equipment, which included vessels, transfer panels and skid equipment, use an identical segment design. This allowed us to develop segment design standards that were followed by our engineering design contractor and the skid vendors.
In the third picture in Figure 1 below, you can see green-colored modules near the bottom of the panel. These are discrete I/O modules that are attached to the AS-i segment in this cabinet enclosure. Transfer panel proximity switches are hardwired from the transfer panel location to these modules. There was a concern about not exceeding the AS-i bus segment length, and so the segment length was minimized by placing the I/O modules in the field termination box (FTB) and not at the individual transfer panels. Today, this may not be a concern because segment length is less restrictive with AS-i segment tuners, which didnt exist when our project was implemented.
FIGURE: 1: FIELDBUS SEGMENT DESIGN
Segment design includes the following components: 1) host control system cabinet with the various fieldbus I/O cards along with their respective segment power supplies; 2) stick-built field termination boxes (FTBs) distributed in the process area; 3) interior view of typical FTB; and 4) interior view of typical skid FTB. (Click the image to open an enlarged PDF.)
|FIGURE 2: CIP CART|
Cleaning bioreactor units requires a portable valve cart to be manually hose connected to various process piping headers on the bioreactor.