Transcript ppt - Cachon | Terwiesch

Figure 3.1.: Photo of the Circored Plant
CFB
Preheater
1st Stage
CFB Reactor
2nd Stage
FB Reactor
~ 110 m
Inclined
Bucket Elevator
Process
Gas
Heat
Exchanger
Iron
Ore
Fines
Electrical
Substation&
Control
Room
Briquetting
Plant
Process Gas
Compressor
Fired Gas Heaters
~ 160 m
Figure 3.2.: Engineering drawing
HBI Product
Activities
• Carried out by resources
• Add value and are required
for completion of the flow unit
• May or may not carry inventory
• Have a capacity (maximum number
of flow units that can flow through
the activity within a unit of time)
Arrows
• Indicate the flow of the flow unit
• Multiple flow unit types possible
(see Section 3.5)
Inventory / Buffers
• Do NOT have a capacity; however,
there might be a limited number of
flow units that can be put in this
inventory space at any moment of time
• Multiple flow unit types possible
Figure 3.3: Elements of a Process
Pre-Heater
Pile of Iron ore fines
Figure 3.4.: Process flow diagram, first step
Pre-Heater
Lock
Hoppers
1st Reactor
Pile of Iron ore fines
Figure 3.5: Process Flow diagram (to be continued)
2nd Reactor
Pre-Heater
Lock
Hoppers
1st Reactor
2nd Reactor
Briquetting
Discharge
Flash
Heater
Pile of Iron ore fines
Finished Goods
Figure 3.6. : Completed process flow diagram for the Circored process
Pre-Heater
Lock
Hoppers
1st
2nd
Reactor
Reactor
Discharge
Flash
heater
Briquetting
Pile of Iron
ore fines
Finished
goods
Figure 3.7. : Completed process flow diagram for the Circored process
Supply constrained
Demand constrained
Bottleneck
(Capacity)
Input
Bottleneck
(Capacity)
Input
Flow Rate
Flow Rate
Demand
Excess
capacity
Excess
capacity
Demand
Figure 3.8.: Supply constrained (left) and demand constrained (right) process
Utilization 100%
Mismatch between demand and
supply at the process level
90%
80%
Imbalance relative
To bottleneck
70%
60%
50%
40%
30%
20%
10%
0%
Preheater
Lock
Hoppers
CFB
Stationary Flash
Reactor heater
Bottleneck
Figure 3.9.: Utilization Profile
Pressure Briquetting Total
let-down machine process
system
15% Outflow
7.5% Outflow
Pre-Heater
Lock
Hoppers
10% Outflow
1st Reactor
2nd Reactor
Discharge
Flash
Heater
Pile of Iron ore fines
Briquetting
Finished Goods
Figure 3.10: Refined process flow diagram accounting for mass reduction
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Figure 3.10: Process flow diagram with multiple product types
Prepare a
Process Flow
Diagram
Extensions required
for working with
multiple flow units
Use different
Colors to mark
Flow units
Compute the
Capacity for
each of the
Resources
Note that capacity
levels may differ
depending on
product type
Use demand to
compute the
implied utilization
levels
Compute the workload across all
product types
Identify the
Bottleneck
Step with highest
implied utilization
Figure 3.11: Summary of process analysis
Compute various
Performance
measures