Safety Shower Recirculation Technology nominated as 2021 Work Health and Safety Invention of the Year Finalist

2021 Work Health and Safety Excellence Awards – Finalists announced

The Department of Mines, Industry Regulation and Safety has nominated Heat Trap Solutions and the invention of the Remote Skid Safety Shower Recirculation Technology as a finalist in the 2021 Work Health and Safety Excellence Awards.

These awards recognise outstanding solutions and innovations to specific workplace health and safety problems in Western Australia. Winners will be announced at the awards ceremony on 22 October 2021 at Optus Stadium.

Remote Skid Safety Shower Recirculation Technology

Heat Trap Solutions Pty Ltd has developed both a Flo-Thru fully flushed self-draining eyewash safety shower and a remote skid based application of their Safety Shower Recirculation Technology for installation in high maintenance mining process facilities and Hazardous Areas in Oil & Gas and Petrochemical projects.

There have been three major developments demonstrated in this latest innovative implementation of Heat Trap Solution’s Remote Skid Safety Shower Recirculation Technology.

  1. Separating the potable water supply for eyewash safety showers from all other process or operational requirements eliminates any disruptive interference between them.
  2. Continuous recirculation provides the opportunity to manage both temperature and water-borne pathogens in potable water supplies for eyewash safety showers.
  3. Eliminating entirely all dead legs and stagnant water in potable water supplies to eyewash safety showers including within the internal pipework of the eyewash safety showers.

The skid-based 5,000L insulated tank, pumps and chillers are located external to the process area and provides the opportunity to manage both temperature and water borne pathogens such as Legionella Bacteria and Naegleria Floweri amoeba in the potable water for the safety showers.The skid mounted chiller maintains the storedpoatble water at a steady 30oC.

Skid mounted constant pressure pumps supply potable water to the Flo-Thru safety showers throughout the process area via the safety shower potable water supply main.The Flo-Thru 316 stainless fully flushed self-draining eye/face wash safety showers have no internal dead legs to hold stagnant water plus a stainless cover lid over the basin.

Constant flow valves in the outlet nozzle of the Flo-Thru safety showers regulate the return flow from each safety shower back to the insulated tank on the skid.

Returning potable water passes through a UV sterilizer before entering the tank.
The skid mounted chiller removes the heat gained from the flow and return lines and keeps the storage tank at an even 30oC.

Kalgoorlie Minesite Case Study

Heat Trap Solutions (HTS) was asked to assist a mining company to resolve a problem they were experiencing at their Kalgoorlie minesite due to excessive water loss from anti-scald valves on eyewash safety showers.

The recommended safe operating temperature for water dispensed from eyewash safety showers is 37.8oC and the water in the potable water tank was in excess of 40oC which is also in excess of the set temperature of the anti-scald valves which are fully open at 39oC.

The Water Corporation was threatening financial penalties due to potable water summer drawdown being in excess of the amounts allotted.

HTS had already established the Safety Shower Recirculation Technology to manage excess temperature and high risk levels of water borne pathogens with eyewash safety shower chillers which continuously recirculate water between the safety shower and the chiller where it passes through a cooling circuit and a UV sterilizer before going back to the shower.

The difficulty in installing our existing eyewash safety shower chillers is they can only service up to six eyewash safety showers each and they needed to be located within the processing facility where they would be exposed to daily washdown with hypersaline water.

HTS needed a new approach to have the cooling equipment located remote from the process area and powerful enough to manage the potable water supply to all 24 eyewash safety showers in the process area.

Without a solution, the eyewash safety showers are unsafe to use in summer and the company faced significant financial penalties and possible restrictions on the supply of potable water for their process requirements.

HTS looked for a new way of providing cool water at the showers. The technology HTS had employed for the chillers previously was to store sufficient chilled water in a tank and use this chilled water to mix with incoming hot potable water to provide 90 to 100 L/minute of 36oC water at a shower for a minimum of 15 minutes.

HTS calculated that the worst-case scenario would be two eyewash safety showers operating simultaneously or consecutively. This would require 4,000 Litres of tepid water if two showers were each dispensing 100 L/minute for 20 minutes. So it was decided to put an insulated 5,000L storage tank on a skid and to keep this skid remote from the process facility.

HTS then developed the Flo-Thru fully flushed, self-draining eyewash safety showers and dedicated potable water flow and return mains to send water out to the showers and to bring recirculated water back to the storage tank via a UV sterilizer.

Dual constant pressure pumps, one on duty and one on standby, provide the recirculation flow and return and dual chillers remove the solar and ambient heat gained by the piping and the storage tank on a series of 50oC days. The chillers keep the stored water at 30oC and the maximum temperature at the furthermost shower is kept below 37oC.

The key aspects of the invention are:

1) eliminating the internal deadlegs in conventional eyewash safety showers and;

2) managing the return flow back from each safety shower to the storage tank.


Deadlegs in the Safety Shower Solution

With the HTS Flo-Thru eye/face wash safety shower, HTS has solved the issue of the deadlegs in the safety shower by putting dual three-way valves in a header at the base of the eyewash safety shower. When a valve is turned on the potable water flows up from the header, through the valve and up the standpipe and out the dispensers. Transit time for potable water to flow from the dispenser is less than one second and water temperature in both the eyewash and deluge shower dispensers is stabilized in less than a second.

Return Flow Issue Solution

HTS resolved the return flow issue by installing 5 L/minute fixed flow orifices in the return outlet of the safety shower header. The constant flow orifices provide a fixed flow over a large range of pressure differences and are particularly suitable for managing return flow from widespread safety showers each with different inlet and outlet pressures. The arrangement with multiple constant flow orifices was tested in the factory before the first field installation.

About Heat Trap

Heat Trap, established in 2011, is a WA company that provides innovative technical solutions to the mining industry to improve the safety, comfort and productivity of workers in Australia’s hottest climates. We are a team of engineers, plumbers and technicians pushing the boundaries of “acceptable” and finding new ways of combining simple, cooling technology to further enhance safety and comfort for individuals working in harsh Australian climates. If you need a safety shower or solution to deal with Australia’s hot climates, contact us here.