What are the steps involve in the plant design?
The mechanical design and development of the plant has three major steps as: -
A. Conceptual layout design.
B. Equipment layout design.
C. Piping layout design.
A. Conceptual layout design.
It is the part of basic engineering package. It consists of following information: -
A. Essential process design requirement such as horizontal & vertical relationship of equipment.
B. Space allocation for basic plant requirement (space required for laboratories, office, storage etc.)
C. Planning for control room, motor control center room etc.
B. Equipment layout design.
It is the detailing of conceptual layout. It is the basic document of mechanical engineering design or in
other words this document is the basis for development of construction drawing by all disciplines. It is
sometimes also referred as plot plan for large outdoor plant.
It consists of following information: -
A. Floor space needed for the equipment and other facilities are shown.
B. Access, removal space, cleaning area, storage space and handling facilities are outlined.
Data / documents required for preparation of equipment layout?
The essential data or documents required for preparation of equipment layout is as: -
A. Process flow diagrams (PFD) and Piping & instrument Diagrams (P& ID).
PFD/ P& ID indicates the inter connectivity of each equipment, information regarding solid handling, gravity feed, line slopes, loop sizes, venting requirement, special piping materials etc. which in turns governs the equipment location to a great extent.
B. Project design data.
This consists of following information as: -
- Geographic location, proximity to roads and railway, topography and local codes and regulations, weather conditions such as rainfall records, seasonal temperature differences, wind direction, outlet points for drains etc.
- The above information such as wind direction influences the location of cooling towers, furnaces,stacks etc. Similarly, the information regarding outlet drain points affects the design of storm water drains and requirements of enclosures.
C. Equipment sizes and Building.
This includes fabricated equipment such as vessels, Heat Exchangers, Reactors, Tanks and proprietary equipment like pumps, Compressors, Furnaces etc. For locating the above, the equipment is grouped to have optimum location for minimum pipe run as well as fallow the process flow sequence.
Basic configurations for the equipment layout
The equipment layout can basically be divided into two configurations:
- The Grade Mounted Horizontal Arrangement:- The grade mounted horizontal arrangement equipment layout seen in the refineries and petrochemical plants. In the Grade mounted horizontal arrangement, the equipment is placed on the either side of the central pipe rack with auxiliary roads. Advantage of this arrangement is that the equipment is located at grade level, which makes it easier to construct, operate and maintain. Disadvantage is that it takes lot of ground area.
- The Vertical Arrangement:- The vertical arrangement equipment layout seen in many chemical process industries.The structure mounted vertical arrangement has equipment located at multilevel in steel or concrete structure. This could be indoor or outdoor. Advantage is of small coverage area and ability to house the facility to suit process requirement or climate conditions.