Water sterilisation in hospitals
The public health benefits of plumbing are never more apparent than in hospitals, but along with the expected quality of medical care comes a high water cost.
In view of recycling water that would otherwise go to waste, a Melbourne manufacturer has developed a unique method for diverting water used to sterilise instruments and dressings for reuse elsewhere in the system.
Originally founded in 1889, Atherton is a leading producer of infection control products, sterilisers, washer disinfectors and warming cabinets for the health care market.
They believe they have identified a new method of reusing waste water in a hospital setting without compromising water quality.
In the ordinary operation of a steriliser, a sterilising cycle lasts about 45 minutes and uses a high volume of steam to pressurise the chamber in order to carry out the sterilising function. The steam is then discharged through a cooling pit to waste.
“In the process of the condensate discharging into waste it goes through a plate heat exchanger, which is made of stainless steel, and uses water as the cooling media. There is no connection between the condensate and the cooling water,” says executive chairman Stephen Atherton.
“In most hospitals potable water is used to cool this steam condensation so it can go to waste. In a conventional system when the potable water comes through the plate heat exchanger it is discharged to waste as well. We’re saying instead of going to waste, if it goes up into a collection tank it can be used for something else in the system.”
Stephen says that there is no risk of cross contamination as the water travelling to the sterilising area is protected by a backflow device and the primary fluid and cooling media are kept separate.
“The plate heat exchanger has two distinct paths that prevent cross contamination – the primary fluid in one chamber and the cooling media in the other. They don’t come into contact with each other.
“In the one in a million chance that there is a split inside the plate heat exchanger and you’re reusing the potable water, it’s protected by a backflow device.”
Hospital sterilisers must be fitted with a plate heat exchanger to cool the condensate before it can flow to waste as regulations stipulate that it must be below 85 degrees before it can be discharged – otherwise the high temperature may melt the pipes.
Stephen says the idea came about over years of industry experience and believes the system can make a valuable contribution to hospital water saving goals, which are becoming increasingly pertinent as water resources dwindle.
“Each one of these sterilisers uses 220L of water per cycle. On average a hospital runs 10 cycles per day so each steriliser uses 2,200L per day.
“For example, the Peninsula Hospital in Frankston has two so they’re using 4,400L of potable water per day. A similar situation is occurring in every major hospital nationally.”
While some hospitals are recycling the water independently for irrigation purposes, Stephen believes a significant number are reluctant to install the system due to concerns about its compliance with the appropriate regulations.
“A lot of hospital engineers say they’re not willing to put their neck on the line if they are confused about the regulations and just keep wasting water.
“There are other companies who sell sterilisers, so there’s no advantage to us – we will still sell the sterilisers. I’m driving this as a plumber who sees an opportunity for water saving. I’m trying to be a good corporate citizen – it’s not going to affect whether we sell the sterilisers or not.”
Director of the Plumbing Industry Commission (PIC) in Victoria Shayne La Combre says the system developed by Atherton is a good example of water saving practices and applications that plumbers are capable of producing.
While the PIC doesn’t endorse individual products, as its role is primarily that of ensuring regulatory compliance, Shayne says the PIC is happy to take queries and confirm in writing that an installation is compliant with relevant plumbing regulations in Victoria. (Plumbers in other States will need to contact their plumbing regulator.)
As water prices continue to rise, Stephen believes the system makes economic sense to hospital management and that with the support of regulatory bodies it could alter the way the steriliser market operates.
“Water is going to become more expensive. You keep hearing from hospitals that they don’t have any money, so we’ve developed a way to save them money and conserve a vital natural resource.”