Engineering systems in manufacturing, industrial buildings
Manufacturing and industrial facilities have some unusual engineering requirements, especially air handling, power needs, and fire/life safety systems.
Jonathan Eisenberg, PE, Associate Manager, Rolf Jensen & Associates Inc., Boston
Brian P. Martin, PE, PDX Electrical Discipline Manager, CH2M Hill, Portland, Ore.
Peter Pobjoy, PE, LEED AP, Chief Design Officer, Southland Industries, Los Angeles
Peter Zak, PE, Principal, GRAEF USA, Milwaukee
CSE: Please describe a manufacturing or industrial facility you’ve worked on—share details about the project, including building location, size, etc.
Jonathan Eisenberg: We are currently working on a large industrial/chemical facility in South America that includes manufacturing space, bulk chemical storage and dispensing rooms, and a central utilities plant. Our role on the project includes building and fire code consulting, as well as detailed fire suppression design.
Peter Zak: American Orthodontics is a world leader in the production of braces and other hardware used by the dental profession. Due to the success and growth of the business, the original manufacturing operations and corporate offices that encompassed multiple buildings was combined and relocated to a single 300,000-sq-ft building purchased in 2012, located in Sheboygan, Wis. The entire facility is climate controlled to maintain a comfortable work environment for the employees to maintain a stable production platform. The renovation included three new electrical services and new rooftop equipment. The entire production process was relocated to the new facility, which required the design of multiple voltage equipment connections and an overhead process/utilities delivery system for plumbing, exhaust, compressed air, and specialized gases to all machines. The transition to the new facility was carefully coordinated between the architect and facilities staff, which produced a detailed utility installation series of plans.
CSE: How have the characteristics of manufacturing or industrial facilities changed in recent years, and what should engineers expect to see in the near future?
Zak: As part of a brazing process, the manufacturer used dissociated anhydrous ammonia, which created a hydrogen by-product. The product moved through a series of chambers on a belt. There was a zero tolerance for draft or airflow that could compromise the brazing process. As the product moved through the chambers, the challenge was to collect the spent hydrogen gas and remove the radiated heat (1800 F) from the surrounding area without creating a draft. This was accomplished with the design of a low-velocity hood system and space pressure controlled ventilation system.
Eisenberg: In our industrial/chemical project work, we see a trend toward more complex processes that often have a need for materials that are both more hazardous and are required in larger quantities. This is driven by significant advancements in chemical process technologies. For example, as semiconductor device sizes continue to get smaller and need advanced capability, the processing involved in their manufacture becomes more involved.
Zak: In the past, the sole purpose of operations was to support facilities production. Maintenance by failure was common, and the primary job of the facilities engineer was to keep things glued together to get the product out. As operating costs began to increase due to age and inefficiencies, it became increasingly difficult to remain competitive and the costs associated with upgrades were prohibitive. There appears to be a tendency for more planning or forward-thinking by industrial clients that includes not only short- and long-term needs, but serviceability, flexibility, efficiency, and sustainability when appropriate. As with anything, cost is always an issue, but there is a concentrated effort to not be short-sighted.
Brian P. Martin: The biggest change that has taken place, and will continue to evolve, is the use of advanced modeling from the initial concept, throughout the design, during commissioning, and throughout the lifecycle of the facility. Different modeling software packages are being used to develop initial costs, to model the airflow throughout the facility, to provide 3-D models for construction, and to provide a 4-D model of the construction sequence and as a part of the measurement and verification strategy for U.S. Green Building Council LEED and energy code compliance. In many cases, these software packages are allowing facilities to meet other long-term strategic goals, such as greater energy efficiency, sustainability, a higher level of facility flexibility for process changes, increased power density, and better integration into the community. All of these have become or are becoming baseline requirements for industrial facilities.
CSE: How does a manufacturing or industrial facility differ from any other large building?
Pobjoy: They now have large open areas to bring equipment in either with roll-up doors or louvers. The equipment is very large and is delivered in large sections that require extensive rigging space, not just for simply installing the equipment, but also in case of future removal. A lot of catwalks and access ladders are installed around the equipment for service and maintenance. Trenches for needed for utilities, drainage, etc. as all utilities are typically required to be accessible for maintenance at all times. Dedicated aisle space must be kept clear for service equipment. Utilities are routed on industrial racks to keep service areas clear and to provide access to valve manifolds, electrical disconnects, etc.
Zak: The most obvious difference is that the building design is usually very fundamental or basic. The structure is purpose-built to support the production side of the business. The power requirements can vary greatly as will ventilation and exhaust air, which traditionally is driven by occupancy in a commercial building but process-driven in an industrial facility. Cooling and heating systems will not only support the building environment but are also used as part of the process.
Eisenberg: Industrial facilities have fire protection hazards that are in a different realm than, for example, a high-rise office building. The actual number of occupants in an industrial plant may be comparatively low and the employees are familiar with the hazards. However, the fire and explosion hazards associated with the materials being stored and used are unique in an industrial setting. The goal from a fire protection engineering standpoint is to plan for these hazards early in the design process.
CSE: What unique engineering issues do you encounter with these facilities, and how do you overcome them?
Martin: During the initial planning stages, most large industrial projects have typically not been announced to the public or to public agencies. Many owners want to know their cost with certainty at a very early stage of the design, but without engaging the authority having jurisdiction (AHJ), this can be very difficult. This is typically overcome by making assumptions early based on the design team’s experience with the local jurisdiction. Once the development has been announced, then these assumptions are validated with the AHJ. Utility and master site planning is also a challenge when you are not able to engage the local jurisdiction and utilities. Owners want to know how long it will take the utilities to ramp capacity to support their plant, but may not be ready to discuss the ramp with the utilities. You can get stuck in a chicken-and-egg scenario, which is typically identified as a risk until the conversation can take place.
Eisenberg: We analyze and recommend solutions for issues such as site separation distance from exposures, bulk chemical storage and transfer, fire protection water supply requirements, and local fire suppression needs for specific chemical process equipment. The key to reaching solutions for these issues that are workable for the facility is to perform a thorough hazard analysis at the start of the project. From this study, we get a clear picture of how the facility operates, and what effective fire protection measures are the most practical.
Zak: Several challenges we encounter are:
- What is the impact of the process equipment on the mechanical, electrical, and plumbing (MEP) systems?
- Which codes are in force?
- Current and future needs of the facility or process
- Future planning.
The issues are best addressed during the planning and schematic design phases if possible. There has to be continuous dialogue with the owner/end user from the beginning of the design to the end of construction.
Pobjoy: In critical systems that require a high level of reliability, systems must be designed with redundancy to maintain operation in the event of a component failure. Major pieces of equipment with very specific requirements for structural support and vibration isolation require close collaboration with the equipment manufacturers in order to coordinate the details. This includes multiple shop drawing reviews, modeling, and templates in the field.