Unit operations, control automation functions

Microprocessor-Based Automation. Automatic systems now arc used lo carry out functions previously performed manually by the operator. These systems may lake many forms (I) integral to and dedicated lo a single chromatograph and (2) as a separate unit which controls one or several chromatographs. The latter are also available for upgrading older manually operated chromatographs to provide automated data reduction and output. 

Current laboratory robot operations use many of the instrument modules familiar in conventional automation syringe drives, relay drivers, current and/or voltage sensors (including A/ D conversion) etc. The uniquely robotic component is a "pick and place" arm which serves as a "mass mover" of sample, solution etc. from one unit operation to the next. The robot controller functions to control both the pick-and-place component and the separate unit operations. Actually it is poor practice to separate any of the... 

Once APMs have been created in the AIMS, a process control and monitoring software (PCMS) module can be constructed that provides for two-way communication between a database that contains the APMs and the instrument control software. This software allows for the retrieval of APM data from the AIMS by a production scientist and transfer to the instmment control software. Electronic transfer of APMs between unit operations in this manner allows for (a) charting of APM progress on the production floor and (b) collection of APM audit data. The PCMS will facilitate maximal process control for the automated chemical synthesis platform. Functionalities for the array information management and process control management software are summarized in Table 3. 

The development status of process control instrumentation lags that of the quality control instruments significantly Nuclear density gauges function in the coal preparation plant environment The slurry concentration meter has application in the intermediate and fine sized coal cleaning circuits and needs to be tested in a preparation plant Other devices, such as ash monitors to control the operation of heavy media baths or jigs are not available and instruments developed for other process industries are not suitable for use in coal preparation plants Modeling studies of the various unit operations are required in order to ascertain the fundamental parameters required to automate the control of these systems Primary process control instrument needs include ash, sulfur, and moisture monitors secondary needs include an on-line washability and ash fusion measurement ... 

A fully automated system for performing detailed studies has been developed to improve the reproducibility and throughput (Fig. 12.2) [8]. It consists of two functional components a sample-deuteration device and a protein processing unit. The preparation operations (shown at the top of Fig. 12.2) are performed by two robotic arms equipped with low volume syringes and two temperature-controlled chambers, one held at 25 °C and the other held at 1 °C. To initiate the exchange experiment, a small amount of protein solution is mixed with a deuter-ated buffer and the mixture is then incubated for a programmed period of time in the temperature-controlled chamber. This on-exchanged sample is immediately transferred to the cold chamber where a quench solution is added to the mixture. 

The automation concept implemented at Conroe is called computer production control (CPC).2 CPC systems are driven by a general purpose process-control computer (48-K core memory) centrally located and programmed to monitor production and equipment operations and perform oil and gas accounting. As shown in Fig. 11, the computer is connected to a supervisory control system with a computer interface unit (CIU) to provide remote data acquisition and control function capability. 

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