Eurotherm Control Solution at Moorfields Hospital
Moorfields Eye Hospital NHS Trust, London, holds stage for new state-of-the-art Pharmacy Manufacturing Unit (PMU). Its main features are sophisticated Water for Injection (WFI) and Clean Steam generation systems for cleaning and sterilization purposes.
The system is designed engineered and commissioned by specialist consultants Honeyman Group Ltd., which provided initial consultancy to MEH, design, supervisory implementation, writing of protocols, validation and final commissioning. System software was designed, tested and built in accordance with the GAMP3 Guide For Validation of Automated Systems in Pharmaceutical Manufacture and also with the requirements of FDA 21CFR Part 11 with respect to electronic records.
It uses a Eurotherm T800 based control solution for all supervisory control functions. The complex system consists of three packaged plants, operating independently with overall supervisory control architecture. In the first plant, reverse osmosis filters and de-ionization processes produce purified water. This is stored as feed water for two additional processes, clean steam generation and distillation for WFI. The entire process is predominantly automated and thus requires minimal operator intervention.
The products of the system are used for a variety of manufacturing, cleaning and sterilizing purposes. WFI is used for production, a number of equipment washing machines and cleaning in place (CIP) tasks, while Clean Steam is used for high temperature autoclaves and steam in place (SIP) purposes.
The three individual packaged plants are self-contained modules with integral local control systems, hand shaking locally and communicating with the central control panel. A number of independent local control panels are also provided for control of dispensing at WFI & Clean Steam points-of-use. The central control panel is also hard wired into the Building Management System (BMS) for soliciting an operator response to alarm conditions.
The Eurotherm T800 at the central control panel is used to execute across-network control operations. Standard features of the T800 controller include a clear touch screen display for screen navigation and execution of operator commands, batch management to ISA-S88, accurate continuous and sequential control, support for Modbus and Profibus, as well as time synchronization.
In this particular application, the controller provides process mimics, bar-graph displays, historic trends, alarm and event logs, keeping the operator fully informed of system status. Key issues in specifying the T800 solution for this WFI/CS system was Honeyman’s clear intention for creating tamper-proof records of key parameters within the fundamental analogue processes synchronized by continuous control. It is operated here in conjunction with five eight-way Eurotherm 2500 I/O controllers.
The five panel-mounted 2500 controllers are used primarily for data acquisition purposes, interconnected with T800 Visual Supervisor via an open ‘Profibus DP’ network. 2500 configuration is achieved using proprietary Eurotherm ‘iTools’ software. Three of the 2500s are mounted with the central control panel, the remaining two operating remotely at local control panels.
The T800 Visual Supervisor logs process data continuously on flash memory for temporary storage, and an integral 1.44 MB diskette for long-term storage with read only restrictions, in a proprietary tamper proof binary format. Process values, events and alarms and trending data are logged once every minute. In terms of access control, the T800 provides four levels of password-protected access to authorized personnel only. A time lock facility ensures that access is cancelled and locked after 15 minutes of operator inactivity.
Roger Newton, Honeyman Project Manager for the MEH system, states that the T800 based control solution was the best possible for both analogue and digital parameters. We have therefore been able get exceptional functionality into compact, cost-effective package. Together with the high level of cooperation provided by Eurotherm’s technical people, made this an obvious solution, which not only meets the current needs of the system but has the flexibility to meet future needs as well.