Energy efficiency is not usually associated with laundering the many different types of linen that pass through health care facilities. Hygienically clean linens are a necessity, and the traditional means of getting them clean involves many chemicals, hot water, and high sewage costs. However, ozone laundering, a relatively new method used in all major upcoming countries, is changing the perception of laundry as a non-energy-efficient necessary evil.
The concept of washing clothes with the aid of ozone (O3) gas dissolved in ambient temperature water was first introduced to the American laundry industry in 1991. The system touted the capability of reducing energy use and traditional wash chemicals while recycling most of the wash water for reuse.Since that time, the number of laundries embracing this technology has grown dramatically. Ozone occurs in nature as a result of electrical discharge (for example, lightning), ultraviolet radiation, or the photochemical action of sunlight on atmospheric oxygen.
To remove the stains from the clothes and disinfect them, ozone is the right choice as it is ecofriendly and doesn't damage the cloth fibre.
Benefits of Using Ozone in Your Laundry
The operational benefits of using an ozone laundry system are many. But the primary benefits are :
The Eltech System enables your laundry to wash in cold water. The energy to heat the water is no longer used. Because the wash is done in cold water, many locations can, and have, turned off their hot water heaters completely.
Water and sewer bills are lower when using an Eltech Ozone Laundry System. With less chemicals injected into the wash, fewer rinse cycles are needed to flush linens of chemical residuals.
An Eltech Ozone Laundry System could mean fewer chemicals required during the wash cycle. This could amount to significant annual savings depending on the amount of linen processed over that period.
The life of the linen is extended by reducing the time and chemicals exposure throughout the laundry process - no hot water, less wash time, less dryer time, less chemicals.
The reduction in time to complete a wash and dry cycle can be reduced by 15% - 20%. If this equates to 10 minutes less per load and there are 6 loads per day processed by that equipment, the daily operation for that load factor could be reduced by one hour.
The Eltech system results in linens that are softer, smell better, and more absorbent. The process is also hypoallergenic. Some laundry room associates have even reported less of a skin irritation when handling the processed linens.
Laundry water is rich in detergents and surfactants, most of which are very slow to degrade. This increases the Chemical Oxygen Demand (COD).This water can no longer be let out in to the sewage system and needs downstream water treatment plants to reduce the presence of these detergents and surfactants along with some of the other chemicals used. The use of ozone for treating laundry water has been found to have many advantages as more and more large laundry units are opting to use ozone for their laundry. Ozone not only breaks down the detergents, but also reduces the use of these chemicals in water. Apart from this, the other advantage is that ozonised water, when used for laundry, there is no need to increase the water temperatures, like for linens. These are washed in ozonised water with lesser amount of detergents and other bleaching chemicals and at ambient temperatures. The resultant wash is better in terms of colour and brightness and they are disinfected as well (which helps in its use in laundry in hospitals). The other advantage is that there is a good deal of saving in water as part of the water is recycled in some of the cases as reported. The waste water is far more environment friendly as compared with regular laundry chemicals without ozone. Ozone reduces COD in the water and the water breaks down the detergents to more biodegradable molecules.
The normal procedure is to dissolve ozone in water in a pre-tank before the laundry machines (individual ozonator for each laundry machine). The ozonised water with some residual ozone in water is the wash water for the laundry. The water is not heated, but used at ambient temperature, thereby saving on the cost of energy zone. Limited amount of detergents and other chemicals are added to the water along with the wash clothes. The amount of detergents and other chemicals required to be added with ozone varies from wash to wash depending upon the type and quantity of wash load and type of detergents and surfactants used. Ozonised water is recirculated with the continuous injection of ozone while the wash cycle is in progress.
A properly engineered ozone system specifically designed for the laundry water treatment reduces the use of water as well as energy cost for heating. Hence the overall benefits include the reduction of water, detergent and energy consumption. This brings in a large savings for the laundry. Besides this, the added advantage is that the waste water from the laundry has much lower COD and requires very little or no waste water treatment prior to letting it out in to the sewage system. This is the major reason why ozone has been increasingly in demand for the laundry water for large laundryunits.
In an aqueous solution, it is an effective biocide, capable of destroying bacterial and viral colonies. It is also effective against molds and fungi and as a deodorizer of air and water. Ozone works well as a disinfectant because upon disintegration it reverts to its original form, oxygen (O2). It dissipates quickly in water temperatures more than 38ºC (104ºF), which mandates the use of lukewarm water. Ozone has been utilized for more than 100 years in Europe in positive applications as diverse as primary disinfection of municipal drinking water supplies, aquaculture, and pulp bleaching. Its widespread use in the United States has been hampered by the preference for inexpensive chemicals (especially chlorine) compared with the expensive, generally unreliable ozone-generating equipment. But with mounting federal government pressure to reduce chemical pollution of the environment, coupled with the development of cost-efficient, reliable, and low-maintenance ozone-generating systems, these systems are gaining popularity. The main benefits of Laundering with ozone are as follows :-
Water heating cost reduction (85-95%): Conventional washing methods require that 70% of wash water be heated to temperatures in ranges of 60º to 82º for proper stain removal when used in conjunction with conventional chemicals. With the ozone washing system, no water is heated to more than 32º C to 40º C, and then only in heavily soiled wash loads.
Chemical cost reductions (60-65%): Ozone substantially reduces the amount of wash chemicals required to achieve the same or better results than conventional processing. The oxidizing power of ozone dissolved in the wash water attacks oxidisable soils and chemically transforms insoluble soil into soluble substances.
Water and sewage cost reductions (15-75%): Major water and sewer savings are achieved only in the closed loop (recycling) configuration, although the open loop (non-recycling) system will reduce water consumption somewhat (20-30%) by cutting the rinse time.
Improved sewage quality (30-50%): The oxidizing power of ozone in the wash wheel breaks down soils, bacteria, and other microorganisms, which constitute the biological oxygen demand, before they reach the drain area. Also, by decreasing the chemicals rinsed down the drain, the chemical oxygen demand levels are greatly improved. Because ozone is an effective waste-water treatment chemical, some laundries have actually saved money by reduced surcharges from city sewer companies.
Increased productivity (10-45%): The ozone washing system can, almost without exception, reduce the wash formula time of any laundry facility. In most cases 25-30% of wash time is spent rinsing or filling and draining the washer while different chemistry is being applied to the linen.