A quatherm’s novel heat exchange module can improve process efficiency and recover pure water in commercial laundry industrial applications. L&N Uniform & Costume in Santa Ana, California, and part of the Aramark family of businesses, installed the TMC Aqua module above its steam tunnel to recover heat and pure water from the intensive process. The initial installation and operation has confirmed ROI on sustainable operations for the company and long-term viability of the Aquatherm’s TMC module.

According to Aquatherm, there have been few commercially viable solutions to-date that recover pure water and heat from high-moisture and low temperature process gas streams. While there has always been a need for this type of solution within various industries, the economics have never been favourable enough to warrant investment. Low heat transfer from existing solutions and susceptibility to corrosion end up costing more to maintain than the value of the heat and water recovered.

Aquatherm’s Transport Membrane Condenser (TMC), uses technology first developed at the Gas Technology Institute based on a nanoporous ceramic membrane to extract a portion of the water vapour and its latent heat from exhaust and process gas streams for plant uses. Water vapour passes through the membrane and is then condensed in direct contact with a low-temperature water stream. Contaminants such as CO2, O2, NOx, and SO2 are inhibited from passing through the membrane by its high selectivity. The recovered water is of high quality and mineral free, and can be used as supplemental makeup water for almost all industrial processes.

TMC technology was initially developed in exhaust applications for industrial boilers. Given its wide range of potential applications, GTI partnered with L&N Uniform and Costume to demonstrate and analyse the efficiency gain within a laundry’s steam intensive industrial process.

L&N Uniform and Costume Service, has been laundering and drycleaning Disneyland Resort’s costumes and linens since 2000, and launders thousands of items of clothing and restaurant supply items daily. There is a steam tunnel in the plant to iron out wrinkles from the garments when they come out of the dryers. There is significant steam lost from its tunnel exhaust stack, detailed effluent parameters are given in Table1.

GTI selected L&N Costume and Linen Service as the host site for the TMC water and heat recovery system field demonstration in the commercial laundry space. The engineering unit design is based on the L&N steam tunnel exhaust stream parameter detailed above.

After initial installation of the heat exchanging unit the following qualitative and estimated resulting output was obtained from L&N. Performance results in Table 2:

According to L&N’s president, the TMC Aqua can recover 400-500,000 BTU/hr of heat and 50 gallons/hour of water. In three hours, enough energy is recovered from the TMC to heat 15 loads worth of water for L&N’s largest capacity washing machine, and enough water is recovered to fill 1-1/2 loads of that same machine. The waste heat recovery made possible by the TMC Aqua module, preheats water so it is available without having to rely on steam from the boiler. This makes it possible for L&N to enjoy an advantage over competitors for production process start-ups in the morning due to the usage of residual heat and energy from existing processes, and faster production times throughout the day, leveraging recovered heat from the steam process and operations.