Cleaning with Dry Steam

Adopting an effective cleaning and sanitizing programme is crucial to eliminate pathogens from surfaces and equipment. With industrial steam machines this type of processing becomes faster and easier as dry steam reduces system and line down times and saves chemical costs. These machines also enable total sanitization and killing of micro-organisms because of the heating shock.

Dry steam technology leaves surfaces dry and is more effective in cleaning difficult to reach workplaces. It is widely used in food industry. Some of the areas dry steam is applied in the food processing include:

• Cleaning and degreasing of workbenches, walls and ceilings
• Removing food residues
• Cleaning of batching systems
• Cleaning and sanitizing of blending tanks
• Removing grease from control panels and electrical boards
• Sanitizing filters and grilles
• Cleaning and maintenance of ventilation ducts
• Thorough cleaning of conveyors, chains, belts, rollers and packings
• Sanitizing refrigeration system
• Cleaning and defrosting refrigeration fins and coils
• Chemical free killing of listeria in drains and pipes

Saturated dry steam

Dry Steam application considerably reduces consumption of water and the use of detergents. Saturated dry steam is also an ecological method of deep cleaning as it removes chemicals, toxins and dirt without using solvents. Latent heat transmitted by super-heated dry steam eliminates all types of pathogenic micro-organisms and harmful bacteria, but does not result in bacterial resistance as is often the case with chemical disinfectants.

Advantages

• No ground contamination
• Saves time by cleaning without swilling and rinsing
• Avoid allergies and skin irritation
• Protects the taste of food

Saturated humid steam

Unlike saturated dry steam, saturated humid steam is the steam in which water is present at a liquid state as micro drops is saturated humid steam. In this case the above-mentioned ratio is between 0 and 1. In Saturated dry steam no water is present in a liquid state as micro drops and the ratio is equal to 1. Saturated dry steam can also be referred to when the ratio value is 0.94-0.95. In other words, near to 1 even if not equal to 1. Such humidity ratio is obtained with boilers which generate steam at a temperature ranging from 140^oC to 180^oC with a pressure between 6 and 10 bar. In this case the steam contains about 5% micro drops of water.

Such steam has a strong sanitizing power to kill micro-organisms/bacteria by thermal shock. It also has a high cleaning capacity with the solvent power of the micro drops of water at a high temperature and the pressure made on the surface to be cleaned.

Pathogenic agents are not resistant to the thermal shock of vapour cleaning. Research has demonstrated that saturated steam treatment eliminates 99% of bacterial fungi and mold on virtually any surface. Unlike other cleaning methods, vapour is able to enter into all surface cracks and crevices. Even with frequent vapour cleaning, pathogenic agents are unable to build up immunity to the thermal shock. The absence of water, the instantaneous drying of the cleaned surfaces and the reduced use of detergents are all factors which help maintain the optimum sanitary conditions.

Phenomenon

When comparing the phases which characterize the traditional cleaning method with saturated dry steam procedure, the advantage of the latter is obvious in terms of efficiency. In fact, there are only three stages required by saturated dry steams instead of the six required by the traditional method.

Traditional cleaning

1. Physical removal of solid dirt
2. Pre-wash
3. Clean/wash
4. Rinse
5. Dry
6. Disinfection

Saturated dry steam cleaning

1. Physical removal of solid dirt
2. Clean only with steam or steam/water/detergent
3. Dry by removal or absorption

With reference to efficacy, the cleaning cycle with saturated dry steam compared with tradition method enables:

1.Thermal shock

An efficient sanitizing due to the thermal shock the micro-organisms are subjected to, moreover there can be no bacterial adoption to the recurrent use of the chemical agents of the disinfectants.

2.Ideal for complex surfaces

A more efficient cleaning of complex surfaces due to the possibility to intervene even in difficult areas which could not be reached by the traditional method.

3. Cleaning electric components

The possibility to clean electric panels, electric connections, engine blocks, refrigerators or electronic parts due to the limited presence of micro drops of water in saturated dry steam and to the rapid drying of the surfaces by means of heat.

NB: Electric panels and machineries must NOT be connected to the main supply while cleaning operation are carried out. It is suggested to use compressed air before connecting to the mains supply in order to remove any trace of humidity.

4. No surface damage

The surfaces treated with saturate dry steam will not be damaged by thermal shock.

5. Save water

A limited consumption of water: about 11/h for every Kw, versus 1500-200 litres/h of water when using water jet machines.

6. Environment friendly

A more economical and environmentally friendly technology, in fact the use of detergent is required in only 20% of the cases versus the 100% requirement of the traditional method.

7. No contamination risk

A safe method for the operator who does not risk contamination as with traditional methods or with low and high pressure bolts of water.

Applications

The environment of bedding is optimal for most dust mites, and comparative studies have shown that the density of dust mites in mattresses to be on average greater than 2500 per gm of dust. Cleaning beds with most vacuum cleaners will not remove dust mite allergens, but could throw them into the air and increase their volatility. Exposure to a high temperature shock will typically prove fatal to house dust mites. Cleaning with dry steam at lethal temperatures has shown to be sufficient to kill dust mites in bedding.

Massimiliano Menichini

General Manager

Menikini

HACCP guidelines

Any area used for the preparation and administration of meals should follow the cleaning and sanitizing procedures. The sequence of the cleaning operations should be carried out as

• Removal of coarse residuals
• Cleansing
• Sanitizing

The removal of coarse residuals should be carried out every time a process ends and it consists of removing from the work areas all the residuals which were originated during the raw material processing and which would hinder further cleaning operations. Traces of flour, sugar, powders, packaging parts, liquid and other materials should be removed by means of sweeping of the floors and dusting of tables and equipment.

Cleansing enables removal of dirt from the surfaces so as to make them become visibly clean. Dirt may be classified as normal dirt or fat dirt. In order to remove such dirts, detergents are used. Attention should be paid to the technical safety data of the detergents as they may have toxic characteristics.

Sanitizing destroys the pathogenic germs and the other micro-organisms. The chemical agents which are mostly used by the firms where food is dealt with are chlorine based components and quaternary ammonium salts.

It is important that sanitization is carried out only after an accurate cleansing, even a great use of disinfectant is not effective if grease residuals and dirt remains on the treated surface. The duration of the contact between disinfectant and surface is very important usually 10-15 minutes are required. Surfaces treated with disinfectant must be abundantly rinsed afterwards in order to avoid contamination of food.

Pressured Dry Steam with temperatures between 140^oC and 185^oC represents the most ecological and modern method to attack dirty surfaces. Pressure, associated with heat action, plays an efficient cleansing and disinfecting action on all kinds of surfaces. Saturated steam therefore enables to operate both in the cleansing and in the sanitizing phase.