Question: Molten metal is poured from a ladle. Total weight of the full ladle is 18 tons. Just as the pour begins, there is a power failure. Fortunately, the hydraulic circuit has a bank of accumulators charged to 2750 psi that will supply the fluid to move the ladle back to a safe position. Acceleration of the load must be limited to 290 in/s2. An operator manually activates a DCV to direct the accumulator fluid to the 7-in. diameter cylinder moving the ladle. This operator cracks the DCV and watches the ladle to achieve the correct motion.
a. What pressure is required to accelerate the load to 290 in/s2?
b. What pressure drop across the DCV must be maintained during the period when the load is being accelerated?
c. If the force to move the load at constant velocity is FL= 2700 lbf , what pressure drop across the DCV is required? Assume the accumulator pressure has dropped to 1950 psi by the time the load has just reached constant velocity.