Cleaning procedures recirculation

Flush the system to remove dust and major debris. Recirculate detergent or alkali cleaner at elevated temperatures to remove grease or oil. Flush and recirculate an acid at elevated temperatures to dissolve any ferrous particles in the system. Flush with water of the same quality as will be used in service. The cleaning procedure shall be validated by making chemical analysis of surface residues. System functional checkout... 

Spray gun cleaning procedures may be a once-through type with collection of spent solvent in a container for disposal or reuse. Some facilities use commercial gun washers. Because gun washers are enclosed and recirculate solvent, they can reduce the amount of solvent lost by evaporation. In either case, the emissions are calculated as the difference between the amount used and the amount recovered. 

A typical batch ultrafiltration plant is represented in Figure 1. It consists of a processing tank, a feed pump, a circulation pump and a membrane unit with a number of modules in parallel. A permeate is obtained from the membranes while the retentate is recirculated until the desired concentration in the processing tank is reached. Then, a cleaning procedure is performed and the system is ready for the next batch. 

Specific logistics for cleaning may vary depending on the type of fryer. For example, a direct-fired fryer with no oil recirculation will require more manual procedure compared with that with an oil recirculation pump because the pump can move the caustic solution through the entire system. Similarly, a kettle fryer will require manual scrubbing for sanitation, whereas a continuous potato chips fryer can use the recirculation pump to get the cleaning action. 

Most of these cleaners use a non-oxidizing biocide such as DBNPA (dibro-monitriloproprionamide) or isothiazolins, and are pre-packaged by vendors. They are typically used following high pH cleaning as a final step. Procedures usually can be a recirculation of the product followed by a good flushing rinse. 

---