Drum washer

Figure 7-51. Suction drum washer (Courtesy of Artos, Germany).

Cationic electrocoating is now used on dryer drums, washer cabinets, and areas where superior corrosion resistance is required. Although cationic electrocoating is somewhat more expensive (10% higher than anodic), its advantages for certain applications justifies the higher cost. 

Pulp and paper. Due to recycling of waste fluids and the need for greater equipment reliability and life span, titanium has become the standard material for drum washers, diffusion bleach washers, pumps, piping systems, and heat exchangers in the bleaching section of pulp and paper plants. This is particularly true for the equipment developed for chlorine dioxide bleaching systems. ... 

When a-sulfo fatty acid esters are used as the major active component in detergents they can cause problems because of their foaming properties. In European horizontal drum-type automatic washers they produce too much foam, and in the rinse cycle of the American and Japanese pulsator-type washers the foam cannot be completely rinsed out [38]. The problem of inefficient rinsing can be solved by the addition of soap [63] or sulfonated unsaturated fatty acid esters [64]. For European applications special foam inhibitors are needed. 

Valves for both cylinders and drums may be composed of a "Monel metal spindle, PTFE gland packing and lead outlet-washer on the cover nut. 

Figure 7-59. Wash tank with spray drum. Figure 7-60. Jet washer (Courtesy of E.

Because of its high vapour pressure and high density MDC should be stored in heavier gauge drums than those normally used for solvents. Mild steel drum ends of 1.6 mm and bodies of 1.1mm are recommended. Washers for bimgs and titscrews should be in B type BPDM synthetic rubber, since MDC dissolves many plastics and softens and shrinks many others. Not only drums but also smaller vessels made of plastic should not be used for storage and distribution. 

The washer-extractor (Miele WS 5220 TR), with a drum volume of220 litres, has a loading capacity of 8-10 kg for delicate outerwear, 12-15 kg of ordinary outerwear and 20-22 kg of normal textiles designated washable by the care label. The special outerwear cleaning is carried out using flie LANADOL process, for which approx. 140 litres of water are used per load. Cycle time is about 25 minutes. 

The temperature sensor, a type of thermometer which fits inside the washer drum, measures the water temperature and signals it to the control unit. The control unit compares it with the temperature needed for the program being used. If the water temperature is too low, the control unit will switch on the heater. The temperature sensor continues to check the temperature and keep the control unit informed. Once the correct temperate re is reached, the control unit switches off the heater and moves on to the next stage of the program. 

The temperature sensor fits inside the washer drum. 

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