Products Isobar® Heat Pipe

Acrolab's Isobar® heat pipes have their roots in thermosyphons. Thermosyphons function as a super-thermal conductor only in a vertical or near vertical plane. In a thermosyphon, a small quantity of working fluid is placed in an evacuated tube. Heat is applied to the base of the tube, causing the temperature of the working fluid to rise — as this fluid heats, it vaporizes. This vapor then migrates to the colder end of the tube where it is condensed. The condensate is returned to the heated tube end by gravity. Since the latent heat of evaporation is large, considerable quantities of heat can be transferred with a very small temperature difference from end to end. The thermosyphon is limited in application because the evaporator region must be situated lower than the condenser region.

The Isobar® Heat Pipe improves on this in that it incorporates a sophisticated solid-state pump to return the condensate to the evaporator site. This pump takes the form of a fine metallic wick that resides tight to the inner wall of the Isobar. This wick, through its capillary action, returns the working fluid to the evaporator without regard to orientation. In a normal environment, the wick permits equal function in vertical and horizontal planes. In applications where the evaporator site is above the condenser, the performance of the Isobar® Heat Pipe is controlled by the capillary action of the wick structure.

Isobar® Heat Pipe are super-thermal conductors have the capacity to transfer large amounts of heat at high speeds in both heating and cooling applications. In fact, Isobar® Heat Pipes have, in some applications and orientations, a thermal conductivity in excess of 20,000 times the rate of a solid copper bar of the same geometry. Isobar® Heat Pipes are also high-speed superthermal distributors. The working fluid constantly changes phase due to the low vapor pressure inside the unit — the device is innately isothermal. Temperature uniformity along the entire length from the evaporator to the condenser is typically in the range of ±1°C while transferring large amounts of energy.

Isobar® Heat Pipes can be designed or retrofitted into many molding applications to improve efficiency related to cycle times, cure rates, mold temperature uniformity, set-up times and recovery rate. Isobar® Heat Pipe technology works equally well with tools drawing their energy from heated platens and with integrally heated molds. Energy sources such as oil, steam or electric heaters may be used.