Product quantity

Besides the quality of various streams, their quantity must also be controlled. If the product bins are nearly full the production rate must be slowed down. Later, after a number of shipments to customers have been made, the rate may be increased. This is called material balance control. 

Often the throughputs of the various process steps in a plant are different, even though on paper they were designed to be the same. This could result in an inadequate amount of feed to one unit while for another unit the feed rate is too great to be handled properly. Again, some type of material balance control is necessary. 

In a petroleum refinery a large number of different products are produced, and the demand for some of these products is seasonal. For instance, there is not much need for residential fuel oil in the summer. The price of products also varies from day to day. To optimize the company s profit, it is therefore necessary periodically to vary the amount of each product produced. This can be done by changing the amounts of material sent to cracking units and reformers and by changing the conditions in these and other process steps. Some petroleum companies provide a computer with the data on market prices, current inventories, and crude oil compositions. The computer output then specifies the operating conditions that will yield the greatest profit for the company. The computer could then make the changes in these conditions directly, or this could be done manually. 

The importance of safety has been discussed in Chapter 4. At this point, it is necessary to look at each stage of the process to see what might go wrong and, if this happened, what might be done to prevent any mishap from occurring. 

For instance, a level gauge in a tank with an alarm on it could warn an operator that unless something is done quickly, the tank may overflow. A spill not only wastes material, but could present a fire hazard as well as a hazard to the environment. A similar alarm system might also alert the operator that the tank is nearly empty. This may be important because a pump downstream may bum up if it continues to operate with no feed. 

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Table 1. Unit Values and Relative Production Quantities for Selected Approved Biopharmaceuticals, 1990—199T...

Economic Aspects. In 1994, there were 16 operating hardboard and hardboard siding mills in the United States. Production was 1.535 x (2) in standard hardboard products. These figures do not include the significant quantities of door skin products made, for which production quantities are not tabulated. Production of hardboards has been relatively stable in recent years, considering them as a group. There have been a few new mill closings and a few mill start-ups. In addition, imports of hardboard have also become more common in recent years. 

Companies whose primary business is the production of ethylene derivatives, such as thermoplastics, tend to use ethane and propane feedstocks which minimise by-product streams and maximize ethylene production for their derivative plants. Table 1 provides a summary of the 1990 production quantity and value of primary olefins petrochemicals and olefin feedstocks in the United States. 

Product Quantity, t Value, Quantity, t Value, Quantity, t Value, ... 

The large candles used by the U.S. Navy have been produced ia the United States by three companies. Mine Safety AppHances Company, Puritan-Beimett Corporation, and Scott Aviation. These sell for 50— 60. Production is less than 10,000/yr. Smaller candles incorporated ia breathing apparatus are produced by equipment suppHers. Production quantities are tied to the number of complete units and the candles are a small percentage of the total price. Production for aircraft oxygen supply during a decompression incident is about 50,000 units per year. In the United States, Puritan-Beimett and Scott Aviation are the primary suppHers as is Draeger in Germany. 

Phosphoms is stored and handled under a protective layer of water. Production quantities are transferred as a Hquid by either water displacement or pumps, with water recycle to maintain the water balance and cover. In earlier times, phosphoms was sometimes stored in underground tanks or pits, but as of the 1990s storage is limited to tanks located inside diked areas that are accessible on the outside for safety and leakage control. 

Production, Storage, and Shipment. A plant of 50,000-t annual capacity could be considered viable for production of isophthahc acid, although no new plants have been constmcted since the early 1980s. Storage of isophthahc acid is in silos. Shipment is in 22.7- and 25-kg bags, 0.5-t and 1-t bags, or hopper tmcks. The far lower production quantity of isophthahc acid and its more varied apphcations vs terephthahc acid mean that high volume... 

Cast and Hand-Molded Refractories. Large shapes such as burner blocks and flux blocks, and intricate shapes such as glass feeder parts saggers are produced by casting sHps, hydraulic cement bonded mixtures, or hand-molding clay or chemically bonded materials. Because these techniques are labor intensive, they are reserved for articles that caimot be satisfactorily formed in any other way, owing to complexity or small production quantities. 

ThaUous sulfate, thaUous nitrate, and thaUous and thaUic oxide are the main compounds produced in bulk quantities by Noah Chemical. Approximately 20 other thallium compounds are also available commercially from Noah Chemical, Cooper Chemical, and Alfa Products, Ventron Division, Thiokol Corporation, in research and production quantities. However, demand for thallium compounds is small and limited to such appHcations as synthetic or analytical reagents. 

Mono- and dichlorotoluenes ate used chiefly as chemical iatermediates ia the manufacture of pesticides, dyestuffs, pharmaceuticals, and peroxides, and as solvents. Total annual production was limited prior to 1960 but has expanded greatly siace that time. Chlorinated toluenes ate produced ia the United States, Germany, Japan, and Italy. Siace the number of manufacturers is small and much of the production is utilised captively, statistics covering production quantities ate not available. Worldwide annual production of o- and -chlorotoluene is estimated at several tens of thousands of metric tons. Yearly productions of polychlorotoluene ate ia the range of 100—1000 tons. 

Product Quantity, f X 10 Reference Ptice, /t Product value, X 10 ... 

The production quantity for the run must he achieved hy executing the appropriate number of hatches. The number of batches is determined from a standard yield for each batch. However, some batches may achieve yields higher than the standard yield, but other batches may achieve yields lower than the standard yield. The ac tual yields from each batch must be monitored and significant deviations from the expected yields must be communicated to those responsible for scheduling production. 

Proration provision for prorating if the contract is ended early Production quantities to be manufactured for fixed term (monthly, quarterly, periodically, as ordered)... 

PRODUCT NAME PRODUCT CODE/ID PRODUCT QUANTITY... 

The analysis indicated that the conformance problems associated with the hub design had a cost of failure of more than 30%. This would represent at the annual production quantity required and target selling price, a loss to the business of several million pounds. As a result of the study the business had further detailed discussions with their suppliers and not surprisingly it turned out that the supplier would only be prepared to stand by its original quotation provided the tolerances on the hub, discussed above, were opened up considerably (more than 50%). Subsequently, this result supported the adoption of another more capable design scheme. 

It is only possible to supply parts with identical characteristics if the measurement system as well as the production processes are under statistical control. In an environment in which daily production quantities are in the range of 1,000 to 10,000 units, inaccuracies in the measurement system that go undetected can have a disastrous impact on customer satisfaction and hence profits. 

Another important parameter is the electric current for discharge. If the current density is too high, the quantity of the hard shell increases and that of the MWCNT decreases. To keep the arc discharge stable and the electrode cool are effective to increase in the product quantity of MWCNT. A considerable quantity of graphite is produced in the cathode deposit even under the most suitable condition to the synthesis of MWCNT. 

Flgure 8-11 A. Troubleshooting desired product quantity and quality. 

Product designers must consider the conditions under which fabrication will take place, because these conditions affect product performance and cost. Such factors as production quantity, labor, and material cost are vital. Designers should also visualize how each product is to be fabricated. If they do not or cannot, their designs may not be satisfactory or even feasible from a production standpoint. One purpose of this book is to give designers sufficient information about manufacturing processes so that they... 

Table 5.2 Substance demand related to the substrate and product quantities in the laboratory scale for the reaction shown in Scheme 5.7.

Annual production = quantity produced per batch x batches per year. 

Table 4.4 is the summary of the mathematical model and the results obtained for the case study. The model for scenario 1 involves 637 constraints, 245 continuous and 42 binary variables. Seventy nodes were explored in the branch and bound algorithm. The model was solved in 1.61 CPU seconds, yielding an objective value (profit) of 1.61 million over the time horizon of interest, i.e. 6 h. This objective is concomitant with the production of 850 t of product and utilization of 210 t of freshwater. Ignoring any possibility for water reuse/recycle, whilst targeting the same product quantity would result in 390 t of freshwater utilization. Therefore, exploitation of water reuse/recycle opportunities results in more than 46% savings in freshwater utilization, in the absence of central reusable water storage. The water network to achieve the target is shown in Fig. 4.14. 

As shown in Table 4.4, the model for scenario 2, which is a nonconvex MINLP, consists of 1195 constraints, 352 continuous and 70 binary variables. An average of 151 nodes were explored in the branch and bound algorithm over the 3 major iterations between the MILP master problem and NLP subproblems. The problem was solved in 2.48 CPU seconds with an objective value of 1.67 million. Whilst the product quantity is the same as in scenario 1, i.e. 850 t, the water requirement is only 185 t, which corresponds to 52.56% reduction in freshwater requirement. The water network to achieve this target is shown in Fig. 4.15. 

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