Cleaning process equipment

Process operations. The third source of process waste we can classify under the general category of process operations. Operations such as start-up and shutdown of continuous processes, product changeover, equipment cleaning for maintenance, tank filling, etc. all produce waste. 

In both batch and continuous processes, it may be necessary to clean equipment to prevent contamination of new product. Materials used for equipment cleaning often cannot be recycled, leading to waste. 

Effective procedure training not only affects process safety, it also affects quality. Process yields, batch turnaround time, and equipment cleaning are all enhanced when the procedures are technically accurate and fully understood by the crews. 

Clean up includes identifying, gathering, storing (when appropriate), and classifying materials associated with a specific toll. Decisions can then be made as to which raw materials, intermediates, and product will be shipped back to the client or kept by the toller. Some off-spec product, retained samples, or unused intermediates may be considered waste materials at this point. Equipment clean up can be extremely important to preserving quality and process safety integrity prior to the next production run of a new product. 

Routine Process equipment cleaning Materials handling (discharge, conveying, bagging) Waste handling/deposition ... 

Improved Operating Procedures 11. Segregate process waste waters from stormwater systems. 12. Optimize the frequency of tank and equipment cleaning. 13. Prevent solids and oily wastes from entering the drainage system. 14. Establish and maintain an emergency preparedness and response plan. 

CFCs have been widely used as cleaning solvents, as they are nonflammable and their toxicity is low. Now, flammable solvents are coming back into favor. A news item from a manufacturer described "a new ozone-friendly cleaning process for the electronics industry, which "uses a unique hydrocarbon-alcohol formulation. It did not remind readers that the mixture is flammable and that they should check that their equipment and procedures are suitable. 

Simple strainers remove gross materials. These should not normally occur in public supply, but strainers are sometimes fitted to protect sensitive equipment or processes against breaks in the main, etc. The commonest form contains a stainless-steel wedge wire screen and is piped with a bypass so that the screen element can be isolated and removed for cleaning when necessary. If the load on the filter makes this kind of cleaning burdensome a self-flushing filter can be used. These can incorporate strainer elements down to 50 pm. 

For some processes, though they would not be classified as batch processes, the period of continuous production will be limited by gradual changes in process conditions such as, the deactivation of catalysts or the fouling of heat-exchange surfaces. Production will be lost during the periods when the plant is shut down for catalyst renewal or equipment clean-up, and, as with batch process, there will be an optimum cycle time to give the minimum production cost. 

Production schedules for batch processes can be sequential, overlapping, parallel, use intermediate storage, or use a combination of these. Such schedules can be analyzed using Gantt charts. Batch processes often produce multiple products in the same equipment and can be distinguished as flowshop or multiproduct plants. Equipment cleaning and material transfer policy have a significant effect on the production schedule. 

Facilities and Equipment System This includes (1) buildings and facilities along with maintenance (2) equipment IQ, QQ, calibration, maintenance, cleaning, and validation of cleaning processes and (3) utilities such as HVAC, compressed gases, steam, and water systems. 

Buildings and Facilities Contamination/Cross Contamination, Water SystemAVater Quality, Aseptic/SterUe Processing Equipment Multipurpose Equipment, Equipment Cleaning and Use Log, Equipment Located Outdoors, Protected Environment, Cleaning of Product Contact Surfaces Raw Materials... 

INORGANIC FILMS Oxide films Air oxidation Excessive heating O2 in deposition equipment Oxidative cleaning processes... 

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