Aquitherm™ - V (Water heated with shrunk-fit displacer body)
The volume displacer-type roll consists of a chilled cast iron shell with a large central bore, bolted-on flanged journals, and a steel volume displacer inserted in the roll bore. The displacer diverts the heating fluid (hot water) to the ID of the roll bore, where it flows through a 0.3" to 0.4" wide annulus formed between the displacer and roll body. The large diameter of the roll bore serves to increase the area available for heat transfer, reduce the distance heat must travel in order to affect the roll surface temperature, and reduce the overall weight of the roll.
The Aquitherm-V has the following operational characteristics:
- Water Heated Only
- Chilled Cast Iron Body
- Shrunk Fit Steel Displacer Body/Can
- Moderate Operating Temp < 250 deg F
- Superior Balancing
- Mass Centering
- Excellent S/C Application
- Great for High L/D Applications
With monoflow rotary joints, the heating fluid enters one end of the roll, passes through the annulus and exits through the other end of the roll. With a duoflow rotary joint (fluid entering and exiting the same end), the fluid enters one end of the roll, passes through the roll through a siphon pipe in the bore of the displacer, then is diverted back through the annulus across the roll and exits through the same end of the roll as it entered.
Advantages of the Aquitherm-V™ type roll are apparent when high length-to-diameter ratios and high speeds are required. Both dynamic balancing and critical speed of rotation are enhanced by this design. This design also enables the roll to be balanced in three-planes, where balancing weights can be added to the center of the displacer body which reduces center whip, as well as removing or adding weight to the ends of the roll body. This generates an exceptionally smooth running calender roll.