Final answer:
Increasing the redesigned drum's capacity to hold 800 liters of petroleum ether will likely increase the pressure on both the walls and floor, and this change will depend on the drum's new dimensions. It's essential that the drum design remains above the discard thickness to maintain structural integrity under the new pressure conditions.
Step-by-step explanation:
When discussing the redesign of a drum to hold 800 liters of petroleum ether, we must consider the impact on the pressure exerted on the drum walls and floor. If a drum is redesigned to hold more liquid, there could be an increase in pressure on the drum's walls due to the larger force exerted by the additional volume of liquid. However, this will depend on the drum's new dimensions. If the drum is taller, the pressure on the walls may not significantly change, but the pressure on the bottom will increase due to the higher column of liquid.
On the other hand, if the drum diameter is increased, the wall pressure could increase because there would be a larger area for the liquid to exert force upon. To ensure the drum does not exceed its safe limits, it's vital to calculate whether the new design stays above the discard thickness after accounting for the wall pressure that would result from the added volume.
Utilizing the historical 'rule of thumb' which suggested 5 diameters side-to-side and 7-8 diameters deep could be revamped to the newer recommendation of 8 diameters side-to-side and 15 diameters deep, ensures that a drum is not only capable of holding the increased volume but also maintains structural integrity under the heightened pressure.