Design capacity

Fig. 9. Impact of excess design capacity on pump energy use, where A corresponds to actual operating flow, and D to the design point if the designer calls...

Such low capacities result ia a formal way of designating capacity specification in the pumping industry, ie, using capacity per hour, rather than minutes. Common uses are for metering and for controUed-volume process services in the chemical process industries. 

Startup time may be defined as the time span between the end of construction and the beginning of normal operation. Hence it should start when the contractor finishes the whole plant or a specified section of it to enable comparisons to be made with other startup times. It is usual to define normal operation as (1) operations at a certain percentage of design capacity, (2) a specified number of days of continuous operation, or (3) the capabihiy of making products of a specified purity. 

Designation Capacity Typical sample charge, lb Motor Mill diameter, in... 

RADIAL FORCE VS. DESIGN CAPACITY WITH A SINGLE AND DOUBLE VOLUTE... 

A PRT in an FCCU significantly increases total plant efficiency. In practice, many PRTs are not operated at their design capacity. Generally, two categories of problems prohibit users from getting the maximum out of their PRT ... 

Overcrowding issues should be noted. Future occupant density is estimated when the ventilation system for a building is designed. When the actual number of occupants approaches or exceeds this occupant design capacity, managers may find that lAQ complaints increase. At that point, the outdoor air ventilation rate will have to be increased. However, the ventilation and cooling systems may not have sufficient capacity to handle the increased loads from the current use of the space. 

Increased Plant Capacity - When an existing plant capacity is increased, the entire pressure relieving system should be reevaluated, even though new equipment has been added. For example, a unit operating at 120 % of design capacity may require additional pressure relieving capacity. 

Dimensions - The inside diameter of the stack is based on the rate of heat release at design capacity. The following empirical equation can be used to calculate this dimension ... 

A butterfly valve in the line to the first stage seal drum limits the maximum flow to the first stage burner. The valve is set by observing the burners while flaring at design capacity. Once adjusted, the valve should be locked in position. 

V = Flare design capacity, m /h (for a flare system, actual and standard cubic meters are virtually equivalent). 

Figures 6-1 lA, B, and C indicate the capacity of various ejector-condenser combinations for variable sucdon pressures when using the same quandty of 100 psig modve steam. Each point on these curves represents a point of maximum efficiency, and thus any one curve may represent the performance of many different size ejectors each operating at maximum efficiency [1]. Good efficiency may be expected from 50%-115% of a design capacity. Note that the performance range for the same type of ejector may vary widely depending upon design condidons.

The three modve steam pressure curves, 100%-90%-80%, are obtained from the ejector manufacturer as is the performance curve of sucdon pressure versus percent of ejector design capacity. This latter curve for an actual installation would show actual absolute suction pressures versus pounds per hour or cubic feet per minute of air or percent design capacity. 

This assumes dry air with no condensables and negligible pressure drop through the system to the ejector. Also, the jet air handling capacity is assumed approximately twice the design capacity, and air inleakage during evacuation is negligible. 

Speed ranges for single-stage and two-stage units are from 500-1,180 rpm. Consult manufacturers for design-capacity ratings. 

For production plant, the energy used per unit produced is lowest when operated at design capacity. At low throughputs, the energy used increases markedly because the standing losses are constant, irrespective of throughput. 

Heating and humidification. The plant is called upon to perform at its maximum winter design capacity. 

The schematic diagram of a lab-scale MSO system with a designed capacity of 0.5 kg PVC plastics/h is shown in Fig. 1. The salt mixture consists of 50 mol% Li2C03 and 50 mol% NaaCO. The eutectic temperature of the used binary salt mixture is 505 C. The selected... 

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