LJ Minor / Nestle Cornerstone Process Plant Expansion
Tec provided the mechanical design for a 75,000 sq. ft. addition to the process facility where Nestlé mass produces soup base and other similar products. The project was design/build and the facility operates 24/7 with the facility fully operational during construction. The design includes providing HVAC to seven bays of process/packaging areas. The addition is divided into areas that are designed with spaces rated as low, medium to high hygiene with the highest quality of air in the high hygiene areas and airflow within the building designed to transfer air to lower hygiene areas. The addition uses HVAC provided by 2-star rated (minimum hollow bodies, cleanable smooth surfaces) air-handling equipment which includes filtration, chilled water glycol and heating water with VAV reheat. The cooling for the 2-star units is provided by the chilled water/glycol system mentioned above with the refrigeration system. The units provide service to the high hygiene production areas.
The two star air-handling unit duct system includes all stainless steel welded ductwork for supply and return air. The outlet distribution in the production space included fabric ductwork that is easily removable and cleanable with minimum downtime. To maintain positive pressure in the return air duct relative to the surrounding air, fan systems were utilized to push the air from the space into the 2-star units. Normally, the air handling unit would be 100% outside air; using this scheme for the return air permitted the air handlers to be run with less outside air which saves energy.
When a production change occurs in any room where a new food product is made in one of the production rooms, Nestlé requires complete change over and clean-up of the room. The 2-star units are designed so that any production room can be in a clean-up mode while other production rooms are operating in a normal mode. After clean-up, the production room must be fully dried before introducing the new product line. A maximum ventilation with cooling and reheating mode is used to expedite the drying time for quick change over of the room. Consideration of the drying time was made to minimize downtime between product lines. During maximum ventilation, all the air was exhausted from the production room.
Other air-handling equipment provides heating and cooling in the facility.