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In accordance with the ISPE Baseline® Guides, raw materials must be charged into any vessel in a cGMP acceptable manner. Parsons has designed charging systems for a wide variety of raw materials that meet these guidelines.
Bulk Raw Materials
Small quantities of liquid raw materials are typically charged via a drum or other small container. In small scale manufacturing, this is accomplished at the reactor level. In large-scale manufacturing, materials can also be charged from a charging floor located above the reactors. Bulk/large quantities of liquid raw materials are generally charged via pumps and hard piping from a tank farm in order to keep the systems tight. These liquids can be piped throughout the facility for charging into the reactors via hard piping, which can be very costly and require a large amount of space. A cost-effective solution that Parsons has employed has been to utilize a manifold concept.
A manifold room can be utilized for piping solvents to a fixed point such as a transfer panel. Using a spool piece or hose, the selected solvent can then be connected from a tank farm source tank directly to a reactor, and the transfer can take place.
Utilizing this method, any bulk solvent can be hard-piped to any vessel. Also, any vessel can be piped to any other vessel. The amount of piping to be installed in a plant can be significantly reduced while adding the benefit of increased flexibility.
The success of such a design is predicated on having the expertise to address the following key areas.
- Check valves to minimize spill during pipe changeover
- Cleaning and storage area for the spool pieces and hoses
- Containment with appropriate scrubbed ventilation
- Controls interlocking for proper line hookup verification
- Low point drainage
- Proper collection of drainage from the manifold
- Spool pieces to connect appropriate lines
Small Quantity Raw Materials
Solids and small quantities of liquid to be charged present a problem in that the quantities are generally small and may be toxic. Adherence with cGMP design suggests having these materials charged without exposure to the environment. Parsons has found that the use of charging vessels for small scale manufacturing charges works well. The "charging vessels" method involves small vessels being loaded with raw materials under a controlled environment such as a hood, and then wheeled into the production area for closed transfer into the production vessels.
For large-scale manufacturing, the appropriate solution is to design a charging room within the facility located over the vessels to be charged. The raw materials are charged into the selected reactor via a charging/charging system or feed tank system as shown above. Parsons' experience in such system designs incorporates the following features.
- Air locks between the staging area and charging hopper
- Proper valving that is compatible with the intended process
- Ventilation/containment hoods
- Chute positions that must accommodate cleaning
- Clean-up and personnel facilities in proximity to charging
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