Bethlehem Porcupine Dryer. Model 4878, S/N 35-1134. This "Porcupine" Dryer has a shell rated for 15 psi full vacuum, working pressure of agitator 125 psi. Jacket: 55 psi. Working capacity: 23 cu ft. All of the contact parts are 316L stainless steel. Unit designed for steam or hot water. Reference dwg # 267D-4V-414. Dryer: 72 in. L x 30 in. dia. Internal vacuum rating: 55 psi. Motor: dual voltage 230/460 V, 10 hp. Agitator. Made to operate under full vacuum. Batch size: 400 to 500 gallon range.