Process variations, equipment

To guarantee shipment on time, you either need to maintain an adequate inventory of finished goods for shipment on demand or utilize only predictable processes and obtain sufficient advanced order information from your customer. When you examine some of the requirements in ISO/TS 16949, you may be tempted to question how you can continually improve performance, reduce costs, and minimize space, material travel, equipment downtime, process variation, etc. and meet 100% on-time shipments. You can t, unless you have a partnership with your customer in which there is mutual assistance to meet common objectives. Without sufficient lead time on orders you will be unlikely to meet the target. However, the standard does acknowledge that you may not always be successful. There will be matters outside your control and matters over which you need complete control. It is the latter that you can do something about and take corrective action should the target not be achieved. 

Finally a 200 B/D 80 tall demonstration unit was used for studying operating parameters, equipment, process variations, and finally catalysts, catalyst treatments, and varying feedstocks. Much of the 200 B/D work has been described in published reports.(8-10) In brief, satisfactory runs with excellent yields and good conversion were made on catalysts containing as much as 12,300 ppm of nickel plus vanadium.(A)... 

Revalidation provides a guarantee of consistent system, process, or equipment usage. It assures that monitoring controls are sensitive enough to identify major problems or drifts in quality and that process or equipment variations have no adverse effect on quality. 

Process Variations. The conventional techniques for tea manufacture have been replaced in part by newer processing methods adopted for a greater degree of automation and control. These newer methods include withering modification (78), different types of maceration equipment (79), closed systems for fermentation (80), and fluid-bed dryers (81). A thermal process has been described which utilizes decreased time periods for enzymatic reactions but depends on heat treatment at 50—65°C to develop black tea character (82). It is claimed that tannin—protein complex formation is decreased and, therefore, greater tannin extractability is achieved. Tea value is believed to be increased through use of this process. 

Commodore has scaled up these treatments and has developed several process variations depending on the nature of the material being remediated. Modules are tailored to each particular remediation site to achieve the highest cost-effectiveness. Mobile equipment is available at the site in the SoLV process, which eliminates the expense of transporting the hazardous... 

Your preparation should also include following a realistic simulation of a process through a complete phase of eight to ten cycles. Realistic simulation implies that measurements of the response to be optimized (e.g., yield, profit, etc.) include some error, or noise, t)-pical of that caused by such factors as raw-material variations, equipment fluctuations and instrument deviations. Because of the conservative nature of EVOP, the response changes and the noise may occasionally have comparable values however, as the number of cycles increases, the simulation will show that even though the best run may vary from cycle to cycle, the effects of the noise will eventually average out so that the true responses and variable effects can be determined. At the completion of a phase, the worksheet calculations... 

It is significant to notice that the concepts and principles to vary and manipulate any aspects of the phenomena will generate the corresponding partial solutions, from which the ultimate intensified process and equipment will be synthesized. Herein, the multiscale approach for variations and manipulations of the phenomena is emphasized. It means that the concepts and principles should be explored at all possible scales for the... 

During the combination of the partial solutions, a major pivotal decision needs to be made is to determine at what scales to implement the processing tasks related phenomena. It can be microscale, or mesoscale or hybridscale (both microscale and mesoscale). Needless to say, it is the corresponding concepts and principles generated for the variations and manipulations of the processing tasks related phenomena that determine the scales of the intensified process and equipment. As a consequence, microscale, mesoscale or hybridscale devices and units are synthesized by the combination of the partial solutions. Thereby, the intensified microstructured devices, the intensified mesoscale process units, or the intensified hybridscale devices are obtained as the conceptual design alternatives from the conceptual process synthesis. The evaluation of PI results is often self-evident as long as the technical feasibility of the intensification concepts and principles can be verified. Nevertheless, once intensified process alternatives have been identified, the further detailed optimization can be performed. 

The Fluid Flame energy systems are designed to run themselves without the need for full-time operators. The system is fully automated and is equipped with annunciators to alert operators when problems arise. A number of electrical process controllers are used to maintain constant temperatures in the bed and in the vapor space of the combustion cell in order to provide steam at constant pressure. Signals from these controllers dictate the feed rate from the metering bin and the amount of excess air fed into the system. The temperature is controlled in order to maintain constant parameters throughout the system and to keep temperatures below the slagging temperatures of the ash. Normal temperature variation is less than +5C° (9F°), and the response time to process variations is rapid. 

Compared with the facilities used in PVD, the CVD equipment does not normally require ultra-high vacuum working environments and the equipment generally can be adapted to many process variations. This great flexibility is advantageous such that it allows many changes in composition... 

As in most processes, a distillation column and other separation processes must be maintained at operating conditions that result in products meeting certain specifications. To achieve this objective on a continuous basis the process is equipped with an automatic control system. Various disturbances can occur during the operation of the process, such as variations in ambient conditions or in the feed flow rate or composition. This can move the process away from design steady-state conditions, causing the products to be off-specification. The automatic controller counters the disturbances by adjusting the operating conditions such as to maintain the process variables at acceptable values. 

Identification and quantification of the desired reaction conditions, particularly temperature and concentration, are necessary to evaluate what may happen if these conditions are not met. This is particularly true where equilibrium considerations are a significant factor in a rate determining step between or among competing reactions. Where multiple products are possible, temperature variations will often significantly alter the ratios of these products. If one of these is unstable or more toxic, this could lead to more stringent temperature control requirements in the process and equipment design. 

The real problem is, of course, the determination of and correlations between process data as input for the model and its solutions. Such expressions are different for each situation, i.e. they depend on feed material and binder characteristics, equipment design and operation, process variations, final product properties, and many more. Data that can serve as input for the model equations must be obtained experimentally. Since access to commercial, often restricted or large scale operations is not available or possible, typically the determination of data and their correlation is based on model experiments. In addition to the difference in size and operation between the laboratory model and the real system, the gathering of data is interrupting and critically changing the process. 

The dies are generally equipped with flow modifiers such as restrictor bars and adjustable lips, to adjust for processing variations such as changes in resin, extrusion temperature, and flow rates. As mentioned, sometimes the lip adjustments are computer-controlled and linked to in-line thickness measurements. 

Pilot scale data for amine removal have been provided by Finland. A biofilter unit (diameter 0.8 m, height 1 m) was installed in a core-making off-gas line, after an acid scrubber. The equipment included a fan and a dewing unit, with which the dampness of the biofiltration unit was adjusted to an optimum level. The odour removal was measured using an olfactometer. Results for the odour and total hydrocarbon levels are given in Table 4.50. Variations in the input analysis are due to process variations. The results show that filtration results in a significant odour and hydrocarbon reduction. 

Continuous, steady-state operation is often regarded as the ideal procedure for many types of process plant equipment, but this is not always true for crystallization processes. Batch operation often offers considerable advantages, such as simplicity of equipment and minimization of encrustation on heat-exchanger surfaces. In many cases, only a batch crystallizer can produce the required crystal form, size distribution, or purity. On the other hand, the operating costs of a batch system can be significantly higher than those of a comparable continuous unit, and problems of product variation from batch to batch may be encountered. 

Account should also be taken of potential changes of duty or use in the lifetime of the equipment. Apart from variations in the product s condition that may arise because of process variations, planned or otherwise, solids commonly vary in condition for a wide variety of reasons. Service conditions also often change in the service lifetime of the equipment. Commonly, feeder duties are up-rated for higher output, formulation changes made, variations of the product s condition, or total product changes made, without any consideration of the effect on feeder power. 

The CVD equipment is relatively simple, does not require ultrahigb vacuum and generally can be adapted to many process variations. Changes in composition during deposition and codeposition of two or more materials are possible... 

Process Variations. ABC, invented in Israel by Holtzman et al., is similar to EE-1. It has been adapted to conveyorized horizontal equipment, but must be followed by a flash electroplating in a proprietary bath. 

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