Energy consumption and water usage are two areas in which food manufacturers can improve the sustainability of their operations. Advances in continuous-process cooking and cooling can help companies make significant improvements in reaching critical energy and water efficiency levels.
Consistent quality and output
The batch method, previously the standard method in commercial cooking and cooling systems, has a number of drawbacks. Maintaining precise temperature and time parameters is difficult, and keeping production rates consistent at the same time is problematic.
Because conveyor-based systems can lead to inconsistent product quality, these have been replaced by rotary drum continuous-process cooker/coolers. These cooker/coolers, which use an augur to move food products through an enclosed water-filled drum, have helped improve throughput and consistency of quality.
Another improvement is the Hydro-Flow system, which applies a combination of air and water injection. This physically and buoyantly supports heavier loads, more evenly distributing food products in cookers and coolers.
Automated controls have helped facilitate such improvements. Programmable logic controllers (PLCs) provide precise control of process functions, including recipe management, and enable uniform cooking temperatures and control of water flow, achieving a totally consistent end process. The control systems also minimize the time required for complex tasks, reduce error, cut cycle times and help increase quality and throughput.
The benefits from these automated process technologies have also minimized energy and water consumption. Compared to batch systems and conveyor-based cooker/coolers, the latest improvements in rotary drum continuous-process cooker/coolers enables them to process the same volume of pasta, rice or vegetables in less time, using significantly less energy to heat the water required for the processes. Monitoring energy and water usage, and managing process systems in these rotary drum cookers and coolers has played an important role supporting sustainability efforts in food processing plants.
With conventional rotary drum continuous-process cooking, the cooker is filled with ambient-temperature water and heated to cooking temperature. In processing pasta, rice or vegetables, the water needs to be heated constantly to compensate for addition of ambient-temperature product.
Further, because water is absorbed into the products during cooking, the load in the cooker increases, adding to energy consumption. Water can be overflowed to reduce starch buildup; discarding the water means wasted resources.
New developments continuous-process rotary drum cooking is now captures and reuses the heated overflow water. It is moved to an adjacent storage tank, pumped through a heat exchanger, then transferred to a reservoir of ambient-temperature make-up water before it is put into the cooker.
This process means less energy is used to get the water up to its cooking temperature. This, in turn, reduces the heating load requirements of the cooker, leading to significant energy savings.
This rotary drum continuous-process cooking and cooling system was developed by Lyco Manufacturing, a leader in the manufacture of commercial rotary drum continuous-process cooking and cooling equipment. It can be integrated into existing rotary drum continuous-process cooking lines.
On the cooling end of conventional systems, considerable energy is expended to reduce temperature after cooking is completed. With this new system, energy usage is reduced with the addition of a mid-process quench step, which adds a small reservoir between the cooker and the cooler.
Instead of moving product from the cooking-temperature water into the chiller water, a mid-process quench cycle uses unheated ambient-temperature water to capture much of the heat. After that step, which requires no energy input, the chiller has less work to do to bring the product down to its low-end target.
The Easy-Flow quench system reportedly provides uniform cooling with very little product damage. Pasta, rice or vegetables are pulled through a cooling plenum at the bottom of the tank by Venturi effect, which increases the velocity of the fluid without pump impeller contact; the Venturi effect creates a pressure differential that pulls the water and product through at a high speed with the capability of moving 300 gallons of water and product through the plenum per minute.
According to the manufacturer, all of these advances in continuous-process cooking and cooling have allowed food processors to significantly reduce their energy and water consumption. In addition, the new capabilities reportedly help food processing firms achieve a better return on their equipment and process investments.