Wire mesh for heat exchanger components

Wire Meshes are open cell structures with low weight and density, high permeability and good heat conductivity that make them suitable for a great range of industrial applications including fluid and heat flow. Thermal spray coating processes were used in the production of advanced high temperature stainless steel heat exchangers.  Stainless steel wire mesh heat exchangers were modeled by connecting the tube to the wire mesh through wire arc thermal spray coating that offered suitable connections between the wire mesh and tube’s outer surface and has potential to replace costly brazing or other metal connection methods.

There have been innovations in increasing the efficiency of combustion and reaching stoichiometric AFR made by many companies across the globe, although some companies have tried to recover the heat of the combustion. By positioning a heat exchanger box above the hot gas stack, the heat of combustion can be captured. Although it is hard to produce heat exchangers that can withstand high combustion temperatures and have a sufficient efficiency to make them commercially feasible.

Waste gases exit flares at temperatures above 1000oC that exceeds the service temperature of most high heat conductivity materials like copper and aluminum that are normally used to develop heat exchangers. High efficiency heat exchanger design can compensate for the low heat conductivity of materials for example stainless steel and Inconel that can withstand high temperatures.

Heat transfer through a heat exchanger depends on its geometry and thermal properties. The magnitude of heat that passes through a material is based on thermal conductivity of the material. To increase the efficiency and functionality of heat exchangers, the chosen material should have high heat conductivity.

Heat exchangers are made to transfer heat between two fluids that are at different temperatures while keeping them separate from each other. Design of heat exchangers varies based on application however it often involves convection in both fluids, conduction in the separation wall and radiation.

Compact heat exchangers are normally used because of their large heat transfer surface area to volume ratio that is named area density. This large surface area is often received by connecting fins to the wall separating both fluids with the fluid with low heat flow coefficient flowing on the fin side of the wall.

Tungsten wire meshes are commercially available in a great range of sizes and there are also several wire orientations popular in the industry. Metallic wire meshes are porous materials comprising of different metals in square, rectangular and round hole shapes. Wire mesh screens are made in different pore sizes, wire diameters and wire types. They are also classified depending on the connection type between the wires such as woven, crimped and others. Woven wire meshes are made in different pore densities. For effective fluid flow and heat transfer performance of wire meshes, mesh pattern and shape are highly significant. Wire meshes have been used in tube heat exchangers to improve heat flow in a similar way to solid plate fins, additionally their porosity also reduces the pressure drop.