Manual cleaning

Fig. 3. Suspended magnets, where A = conveyor belt width B = suspension height C = overall height D = distance to magnet centerline and E = location of lift point, (a) Manually cleaned over conveyor mn system, (b) manually cleaned over head pulley, and (c) self-cleaning separator over head...

More frequent manual cleaning of tubes was suggested as on-line sponge-ball cleaning did not appear effective. Higher concentrations of tolyltriazole were fed with no discernible effect. 

Swedish standard SIS 055900 contains two pictorial standards for manual cleaning, St2 and St3. Both require the removal of loose millscale, surface rust and foreign matter. The second and higher standard describes the prepared and dusted surface as having a pronounced metallic sheen. The St2 preparation is described as a faint metallic sheen . Both are expected to correspond with their respective coloured prints in the standard. These relate to four grades of new unpainted steel ... 

Where low-cost labor is available, operators can provide intensive manual cleaning during the annual plant shutdown period. However, this is not a model for operational efficiency, and low-cost labor is seldom that low when quality and productivity is factored in. In the long run, it usually is far better to aim for a higher operational standard from the beginning. 

Although generally associated with manual cleaning, it is possible to obtain fully automatic bag filter systems. These have a hydraulic backwashing and bag-cleaning device solidly attached to the steel bag housing. 

There are several approaches to cleaning. The favored approach is clean-in-place (CIP), in which cleaning solutions are piped to the vessel under computer control. In cases where CIP is not suitable, clean-out-of-place (COP) is used. This approach is mostly for smaller items. COP may be carried out manually or with automated tanks. A third approach is manual cleaning, although this is prone to human error and is not generally adopted. 

With many polymerizations reactor cleaning is very important. On large reactors manual cleaning of the inside walls is less economical than mechanical or chemical cleaning. In manual wall cleaning with scraper tools a scaffold must be erected in the reactor, or a raft must be introduced to float on water, on which the workmen can stand and lower the level from which to work by draining water away. 

Nevertheless, there are still some cooling systems (especially closed-loop systems) that do not receive any form of chemical inhibitor dosing or other treatment. This situation typically persists because the operator either remains uneducated or skeptical concerning the benefits and cost-effectiveness of water treatment or relies on low-cost labor to provide regular manual cleaning. 

The sealed box is the simplest but most labor intensive process. In this process, whole tires are stacked manually in a steel cylinder equipped with airtight heads on each end. Heat is added either externally or directly inside the reactor until the reactor reaches the desired pyrolysis temperature. The reactor is then held at that temperature for several hours. Next the reactor is cooled, opened, and manually cleaned to remove char, wire, and fabric. It is... 

Pros and cons of manual cleaning Clean in place (CIP)... 

Training operators in the cleaning SQP is an important part of validation maintenance, particularly for manual cleaning methods. Training in a manual method should include a classroom discussion of the method, observation of the SOP being performed by a trained operator, and then demonstration of proficiency by performance of the SQP by the trainee. Training should always follow revision of the SQP, and retraining... 

---