Belt unit, construction

Belt units are constructed such that the continuous belt is suspended between a driven pulley above the fluid to a lower, idling pulley immersed below the fluid surface. As the belt descends into the liquid, the floating oil adheres to both sides of the belt. Wipers are attached to the upper unit to scrape the oil, which drains into a trough that conveys it to storage containers. 

While a new tire may have excellent resistance to crack initiation and propagation between the steel belts, an aged tire of the exact same construction can exhibit dramatically reduced crack growth resistance, which in some cases may contribute to tire failure. To further underscore the point, the United States National Highway Traffic Safety Administration (NHTSA) determined that tire aging was a main contributor to the Firestone Wilderness AT tire recall [1]. Figure 34.1 shows the failure rate of Wilderness AT tires as a function of tire age (determined from date of tire manufacture). 

A different iterative method for the construction of ribbon and belt type molecules using tetrafunctionalized arenes and cyclophane monomers was developed by us [42]. The newly designed key compound 23 allows a repeated elongation of a ribbon type molecule by two benzene units (Fig. 12) [43]. 

Conveyor systems are applied in a number of areas in the rubber industry. The types used can range from simple canvas belt conveyors used for haul-off from conventional extruders, to systems used for transport and cooling of profile products, both in and emerging from continuous vulcanisation units. The latter types have to be resistant to the temperatures used in such systems and are variously constructed from glass fibre-reinforced polytetrafluoroethylene or a silicone rubber covered belt. 

Rope and belt skimmer units are quite efficient at removing thin layers of LNAPL from both open-trench wells and larger surface areas (ponds, or even manholes). Recent developments include development of belts that are sufficiently narrow to use in open wells. Both smooth flexible-tube and belt systems rely upon continuous rotation of a flexible closed-loop tube (or belt) constructed of an oleophilic material (Figure 7.16). The automatic unit draws the oil-covered tube (or belt) through scrapers and returns it to the surface to gather more oil. 

Figure 11.11. Continuous horizontal vacuum filters especially suited to free settling and draining solids, (a) Principle of the conveyor belt filter units may operate up to 0.S m/sec with a cycle time up to 10 min and produce cake thicknesses up to 15 cm. (b) Showing the construction of a grooved rubber belt support for the filter cloth of the belt filter (Purchas, 1981). (c) Rotating horizontal vacuum filter the unit has readily accessible piping and is amenable to thorough washing of free draining solids (Dorr-Oliver Inc.).

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