Cpgp day01-session 5 - drawing a process flow diagram 2012 final
- 1. Drawing a Process Flow Diagram
- 2. What is a PFD • A process flow diagram is a pictorial representation of what is happening in a process in a sequential order • It is a snapshot of the process at the time of inspection • It is a paper based tool
- 3. Why Draw a PFD • Industries do not know – What is wasted – Where is it generated – How much is wasted
- 4. PFD for Cleaner Production A simple diagram which uses only three main symbols and one auxiliary symbol Not to be confused with other types of diagrams
- 5. Symbols to be Used Rectangle is used for representing a process step Arrow is used to show link and direction Ellipse represents the beginning and the end of diagram A Circle (with character or sign) is used to show continuation of a process
- 6. Tips in drawing a PFD • List all the process steps prior to drawing PFD • Break larger steps into simpler steps as much as possible • The PFD is drawn from top to bottom of a paper • Arrows link process steps in sequential order • Arrows linking process steps must always be directed downwards (Top to Bottom PFD) • Labour, Time and Capital equipment not included as inputs or waste streams • Inputs should be consumable items/material only
- 7. Always Start With an Ellipse • Draw an ellipse on the top of the page and • Insert the name of the main raw material which undergoes the change to form the final product within it Raw Peanuts
- 8. Drawing Process Steps • Process steps (activities) are depicted by rectangles • Rectangles are drawn below the elipse, one per process step • Sequential process steps (are linked by downward arrows • Insert the name of the process step inside the rectangle Storing Raw Peanuts De-shelling Sorting Frying
- 9. Indicating Resources Used • Resources used are known as INPUTS • Inputs are indicated on the left side of the rectangles (process steps) • Inward arrows are drawn from each input material towards the rectangle • Inputs are consumable material used to carry out the change to the main raw material at each process step Electricity (Lighting) LP Gas Coconut Oil Hot air Storing Raw Peanuts De-shelling Sorting Frying Electricity (Lighting) Electricity (Lighting)
- 10. Indicating Waste Streams • Waste streams are known as OUTPUTS • Outputs are indicated on the right side of the rectangle • Outward arrows are drawn towards each Output stream from the rectangle • All waste stream generated at this point should be indicated on the PFD
- 11. Shells Spilt nuts Dust Oil Spills Nut spills Oil Evaporation Waste Heat Excess gas Over fried nuts Storing Raw Peanuts De-shelling Sorting Frying LP Gas Coconut Oil Hot air Electricity (Lighting) Electricity (Lighting) Electricity (Lighting) Energy Loss Foreign Matter Spilt nuts Dust
- 12. How to End the PFD • The PFD is ended with an elipse depicting the finished product Main Raw material Finished product Inputs Outputs
- 13. Shells Spilt nuts Dust Oil Spills Nut spills Oil Evaporation Waste Heat Excess gas Over fried nuts Storing Raw Peanuts De-shelling Sorting Frying LP Gas Coconut Oil Hot air Electricity (Lighting) Electricity (Lighting) Electricity (Lighting) Energy Loss Foreign Matter Spilt nuts Dust Oil DrainingOil Paper Drained Oil Used Oil Paper Salting Packing Salt Spilt Salt Spilt nuts Packing Material Rejected Packing Material Spilt Nuts Overfilled packs Fried Salted Peanuts
- 14. Continuation • If one page is insufficient to complete the PFD, use another. • Do not try to draw two PFDs on one paper. • Arrows are never directed upwards The following method is not correct
- 15. The following method though correct is not preferred
- 16. The following method is correct and preferred Major Raw Material A Page 1 Finished Product A Page 2
- 17. Repeated Processes Filtering Mixing Bagasse Juice 1 Water Electrical Energy Sugar Cane Crushing Juice 2 Juice 3 Electrical Energy Filtering BagasseElectrical Energy Mixing Filtering BagasseElectrical Energy Water Electrical Energy
- 20. Auxiliary Processes • Auxiliary processes are those that support the main process. • They include cleaning, Bottle washing, Steam Generation, Water treatment etc. • PFD for Auxiliary processes should be drawn separately and linked to the main PFD
- 21. Chemical Spills Waste Chemicals Cleaning Chemical Washing Hot water rinsing First Washing Bottles Cleaned Bottles B Water Electricity (Lighting) Electricity (Lighting) Electricity (Lighting) Electricity (Lighting) Chemicals Hot Water Energy Loss Energy Loss Water Spills Waste Water Energy Loss Energy Loss Hot Water Spills Waste Water Boiling (Boiler) Fuel Chemicals Air Flue Gas loss Radiation Heat loss Steam Leaks Blow-down loss Water Steam A Page 2 Mangoes Washing Peeling & Cutting Crushing Mixing Page 1 Finished Product Cooking Cooling Bottling Labelling and Storing Electricity (Lighting) WaterElectricity (Lighting) Electricity Electricity Steam Electricity Sugar Electricity Bottles Electricity Caps Electricity Labels A B
- 22. How to Indicate Cleaning Processes • Pay attention to processes such as cleaning operations – Floor Cleaning – Machine Cleaning – Equipment Cleaning • Such operations should also be indicated on the PFD
- 23. This Method is Wrong! Mangoes Washing Peeling & Cutting Crushing Mixing Bottled Mango Juice Cooking Cooling Bottling Labelling and Storing Electricity (Lighting) WaterElectricity (Lighting) Electricity Electricity Steam Electricity Sugar Electricity Bottles Electricity Caps Electricity Labels A B Water Detergents
- 24. How to Indicate Cleaning of the Juice Cooking Pan Page 1 Mangoes Washing Peeling & Cutting Crushing Mixing Bottled Mango Juice Cooking Cooling Bottling Labelling and Storing Electricity (Lighting) WaterElectricity (Lighting) Electricity Electricity Steam Electricity Sugar Electricity Bottles Electricity Caps Electricity Labels A B C Page 2 Washing Electricity (Lighting) C Pan Cleaning Process Detergents Hot Water Energy Loss Waste Water Water Spills Detergent Spills
- 25. PFDs for Services • The PFD for a service organization may be drawn as a block diagram/Unit Process • These are prepared for activities that do not have sequential steps, such as Boilers, Housekeeping activities in Hotels, Kitchen activities in Hotels etc. House keeping Room Cleaned Room Energy Room cleaning chemicals Cotton Rags Toilet cleaning chemicals Tissue Paper Toilet paper rolls
- 26. Use ofUse of Raw MaterialsRaw Materials ManufactureManufacture DistributionDistribution UseUse DisposalDisposal Product Life CycleProduct Life Cycle For PFDs are not drawn for products We can draw Life Cycle Diagrams Can we Draw PFDs for Products?
- 27. Wording • All process steps are considered to be dynamic (process step is taking place at the time of observation) • Therefore all steps are referred in present continuous – Checking Frying Dyeing Drying
- 28. • Do not Mention the equipment as the process step • These terms are wrong - Dry - Dye - Fry - Dried - Dyed - Fried - Dryer - Dying Machine - Frying Pan
- 29. Additional points • However small the resource quantity may be indicate it on the PFD. • However small the waste stream may be indicate it on the PFD. • When considering the process steps the normal, abnormal, occasional ,accidental and maintenance operations should also be taken into account
- 30. Other Tools
- 31. Ecomapping - One little picture says more than a long speech ! • A visual, simple and practical tool to analyse and manage the environmental performance of companies industries • An easy, creative and systematic method of obtaining environmental data • An awareness - creation and learning tool based on the physical reality of the company • A dynamic inventory of the changes in the environmental behaviour of the company
- 32. How to Use Eco-maps • Indispensable materials – A4 -sized paper and a photocopy machine. • Time needed – Less than one hour of work for each map. • When to do it? – After the end of the accounting year. • How often should they be up-dated ? – Once a year, or if the site is renovated, or activities are extended. • Filing – With documentation for your environmental management system, with your annual accounts . • Who can use them? – The maps can be used by many different types of companies: from small manufacturing and service companies to large structures and local authorities.
- 33. How to Eco-map 1. Prepare Map of the urban situation • Make a map of the site, seen from above, including car parks, access areas, roads and the surrounding environment. • It should show the real situation.
- 34. 2. Map of the site • Draw the outline of the site using a scale and showing the interior spaces. This map should be copied and will be the basis for the work to be done. • The maps should show the real situation - they should be simple, recognisable and in proportion. Maps should have a date, a name and a reference. Integrate one or two significant objects such as machines and boilers, which will enable the user to orient himself with the site easily • If the site covers very different areas, individual maps of the different areas can be prepared and brought together.
- 35. 3. Symbols • Develop your own symbols, but use at least two Hatched lines: small problem (area to be monitored, problem to be studied) • Circle: large problem (stop, corrective action) • The more serious the problem, the thicker the circle
- 37. Case Study