Tanks and Equipment: Cleaning and Sanitation
Cleaning and sanitizing tanks, presses, crushers, and other equipment is one of the largest uses of water within a winery. Improved equipment cleaning and sanitation practices can significantly reduce both the amount of water used, and the strength of the wastewater leaving the winery.
Case Study: Tank Cleaning & Sanitation at Stratus
Stratus switched from a caustic-citric wash process to using Cleanskin, an alkaline detergent that does not require a citric rinse. To further reduce water used for tank cleaning, Stratus implemented a water recycling procedure, where wash water from the bottom of a tank was pumped to the Gamajet nozzle inserted in the top. Once the tank is clean, the Gamajet is moved to the top of the next tank and wash water is pumped from the bottom of the first tank into the new tank being washed. When all wash water has been transferred, the collection hose is connected to the bottom of the new tank to recirculate wash water until the tank is clean.
This process is repeated to clean subsequent tanks and Stratus tries to schedule tank cleanings so that as many as possible can be washed in one chain.
Reduce tank transfers and equipment change-overs
Reducing tank transfers can significantly reduce water use and product loss. Using in-line floatation and in-tank blending can reduce the total number of tank transfers required.
If possible, dedicate a press for white varietals or schedule as many sequential red loads as possible to reduce the amount of times you have to clean red pomace from presses.
Develop standard operating procedures
Developing standard procedures for tank washing is a low-cost approach that can produce large improvements. Standard procedures may include:
- what type of equipment to use
- what temperature of water to use
- how long wash and rinse cycles should last
- how water is captured and reused
Wineries should develop these standard procedures to minimize water use while still ensuring adequate cleaning.
Use dry cleaning techniques
Using dry cleaning techniques including squeegees, non-abrasive clothes or sponges , and shovels, to remove residual solids. This has multiple benefits: reduces the amount of water needed to clean the equipment; prevents organic material from entering the wastewater stream; and reduces the liquid content of solids that can be composted.
Capture and recirculate water and caustic
Caustic wash and other cleaning agents can be recirculated within and between tanks. During multiple tank cleanings, additional caustic can be added to the solution if the pH drops to the point where it is no longer effective at cleaning.
In addition, final rinse water from equipment can be used as first-wash water for subsequent equipment cleaning.
Use sanitation methods that don’t require a final rinse
Certain sanitation methods, such as peracetic acid or steam, do not require a final rinse to remove chemical residue, thereby saving water.
Use water-efficient equipment
Clean-in-place systems can be costly to install but they can significantly reduce the amount of water required to clean tanks and facilitate the reuse of wash water. These systems also save time in the cleaning process.
Other water-efficient equipment that can be used by wineries includes advanced impingement nozzles, spray ball nozzles, or pressure washers to reduce cleaning time and water use.
Consider ease of cleaning when purchasing new equipment
Sharp corners, joints and protrusions all require additional effort and water to clean. When purchasing new equipment, consideration should be given to features such as rounded corners, fully polished seams, and other features that make cleaning easier.