Capillary device for use in heat pipe and method of manufacturing such capillary device

A method of manufacturing a heat transfer apparatus in which heat is transferred by a working fluid from an evaporator plate to a condenser plate through a vapor space disposed between the evaporator plate and the condenser plate, the method comprising placing a first layer of powdered material on the condenser plate, melting spaced-apart selective regions of powdered material in the first layer of powdered material by an energetic beam to form fused powdered material regions separated by unfused powdered material regions, wherein each fused powdered material region in the first layer of powdered material forms a fused porous region adjacent the condenser plate, placing successive layers of powdered material over the first layer of powdered material, melting spaced-apart selective regions of powdered material in each successive layer of powdered material by an energetic beam to form fused powdered material regions separated by unfused powdered material regions, wherein each fused powdered material region in each successive layer of powdered material aligns with a fused powdered material region in an adjacent layer of powdered material and each unfused powdered material region in each successive layer of powdered material aligns with an unfused powdered material region in an adjacent layer of powdered material, wherein the fused powdered material regions of the successive layers of powdered material form a plurality of rigid porous walls to at least partially define a plurality of chambers that extend between the evaporator plate and the condenser plate, wherein each chamber encloses a plurality of unfused powdered material regions, and wherein each fused powdered material region in a last layer of powdered material forms a fused porous region adjacent the evaporator plate.

A method of manufacturing a capillary device for use in a heat transfer apparatus in which heat is transferred from a first region to a second region by a working fluid, the method comprising, the method comprising:

• placing successive layers of powdered material over a donor material and selectively melting regions of each successive layer of powdered material by an energetic beam, including
• selectively melting the powdered material of each layer in a first plurality of successive layers of powder material to forms first portion of a solid housing of fused powdered material proximate the donor material, wherein the solid housing defines an interior space,
• selectively melting each layer in a second plurality of successive layers of powdered material to form (i) a second portion of the solid housing of fused powdered material adjacent the first portion of the solid housing, (ii) a ring-like capillary structure of porous fused powdered material along an interior surface of the second portion of the solid housing, and (iii) a region of unfused powdered material disposed within the ring-like capillary structure,
• selectively melting each layer in a third plurality of successive layers of powdered material to form a third portion of the solid housing of fused powdered material adjacent the second portion of the solid housing 1 and distal from the donor material,
• removing the unfused powdered material from the region disposed within the ring-like capillary structure to leave a central elongated channel within the interior space of the solid housing, and
• wherein selectively melting each layer in the second plurality of successive layers of powdered material forms separated porous capillary protrusions projecting radially into the central elongated channel from an inner surface of the capillary structure.

A method of manufacturing a heat transfer apparatus in which heat is transferred from a first region to a second region by a working fluid, the method comprising:

• placing successive layers of powdered material over each other and selectively melting regions of each successive layer of powdered material by an energetic beam, including
• selectively melting the powdered material of a first plurality of successive layers to form a first portion of a solid housing of fused powdered material, wherein the solid housing defines an interior space;
• selectively melting a second plurality of successive layers of powdered material to form (i) a second portion of the solid housing of fused powdered material adjacent the first portion of the solid housing, and (ii) a first portion of solid circumferential vapor channels of fused powdered material within the interior space,
• selectively melting a third plurality of successive layers of powdered material to form (i) a third portion of the solid housing of fused powdered material adjacent the second portion of the solid housing, (ii) a second portion of solid circumferential vapor channels of fused powdered material adjacent the first portion of solid circumferential vapor channels, and (iii) a circumferential ring-like capillary structure of porous fused powdered material within the interior space, wherein the capillary structure extends along a length of the solid housing and defines an annular chamber, and (iv) a region of unfused powdered material disposed within the annular chamber of the ring-like capillary structure,
• selectively melting a fourth plurality of successive layers of powdered material to form (i) a fourth portion of the solid housing of fused powdered material adjacent the third portion of the solid housing, and (ii) a third portion of solid circumferential vapor channels of fused powdered material adjacent the second portion of solid circumferential vapor channels, and
• removing the unfused powdered material from the annual chamber disposed within the circumferential ring-like capillary structure to leave a central elongated bore within the interior space of the solid housing.