Mist humidification systems
Pressure humidification of the air with water mist
We design and implement industrial humidification of air with water mist for the needs of industrial halls with significant cubic capacity (up to 100,000 m 3 and larger). We are able to build a system with any large water flow and precision of humidity control in the standard up to 3% RH. Depending on the specification of the facility, we use mechanical filtration, absorbers of dissolved mineral compounds or filters based on reverse osmosis.
General characteristics of mist systems
- water flow: 100-950 l/h (application to halls with a cubic capacity of up to 100 000 m 3)
- number of independent humidification zones: 3
- possibility of remote control of the fog system from the Internet
- thanks to the integrated filter station, no limestone raids on the equipment of the humidified room
- critical event alert system with SMS notification
- possibility of integration with ventilation and air conditioning systems
The principle of operation of fog systems – industrial air humidification
Air humidification in rooms with a significant cubic capacity is carried out on the basis of pressure fogging. Purified and demineralized water is subjected to a pressure of 70 bar, and then sprayed through specialized pressure nozzles made of precision ceramics. Thus, the obtained fog is characterized by drops of several to several microns. With this size of droplets, the evaporation area of each liter of water applied is more than 600 m2. As a result, water, taking heat from the environment, evaporates in a very short time after leaving the nozzle, causing a very rapid increase in relative humidity of the air.
Problems of low humidity in industry
Electrostatic charges
A humidity level below 30% contributes to a significant increase in electrostatic charges on all kinds of non-conductive surfaces (dielectrics). This situation usually takes place during the heating period when the frosty air from the manor is heated by heating devices to room temperature, as a result of which its relative humidity drops sharply. The effect of excessive accumulation of charges is damage to electronic equipment as well as the risk of fire or explosion of volatile substances. A very effective method of reducing electrostatic charges in a large industrial area is to increase the relative humidity of the air by using a fog humidification system.
Dust
The reduced relative humidity of the air in many areas of industry promotes the formation of volatile particulate matter. This is caused partly by the accumulation of electrostatic charges and partly by a decrease in the density of the water-free material. The use of a fog humidification system reduces dust by eliminating electrostatic charges, reducing the volatility of solid particles by increasing their density, and by directly absorbing dust particles by micro droplets of fog (as a result of which the particles merge into larger groups losing their volatile properties).
Health problems
The ideal level of relative humidity for humans in terms of comfort and health is RH = 40-60%. Lower humidity causes discomfort, drying of mucous membranes as well as respiratory diseases. Too high humidity is the cause of a feeling of shortness of breath, fatigue, causes distraction, and also promotes the development of spores of mold fungi.
Storage issues
Each stored hygroscopic material interacts with the surrounding air. It absorbs moisture from too humid air and gives the water contained in itself to air that is too dry. The problem occurs mainly in the storage of food products, wood, tobacco, etc. Loss of water from them to the environment causes weight loss and quality loss – cracking and deformation in the case of wood-based products, paper; brittleness of fibers in the textile industry, etc.
Problems in the process of gluing and varnishing
Nowadays, when nitro varnishes are replaced by water-based varnishes or polyurethanes, the proper relative humidity is of particular importance. The recommended air humidity when applying the varnish coating is 50-60%. In the case of applying water-based varnishes at a humidity of 20%, the water, which is the support base for this type of varnishes, rapidly evaporates, which leads to the formation of surface tensions and, as a result, the formation of the so-called water. “Orange peel” and cracks. The situation is similar in the case of polyurethane adhesives. In the bonding process, proper humidity is equally important. The effect of not meeting the proper parameters of gluing in the carpentry industry is peeling off veneer, ungluing parts of furniture, doors and windows.
Maintaining a constant level of humidity when air humidification is in operation
Thanks to precise temperature and humidity sensors, we are able to control air humidity with an accuracy of 2% RH. Maintaining humidity at a constant level is extremely important. Humidity fluctuations are very harmful, especially when storing cardboard or wood. Frequent evaporation and soaking of water causes a decrease in the durability of the material and its delamination. Therefore, in order to prevent fluctuations in air humidity, precise sensors should be used, which, in combination with an intelligent controller, precisely control the amount of water in the air. However, it is necessary to take into account the air exchange that takes place in the room that we humidify. Air drawn in from the outside usually has less humidity than that ejected from the inside. In addition, heating it to the right temperature causes a further decrease in humidity. All these factors must be taken into account when designing and installing an air humidification system. The proper operation of an industrial humidification system requires appropriate algorithms and specialist knowledge combined with many years of experience.
What is relative humidity
Relative humidity (RH) is the percentage ratio of the amount of water vapour dissolved in the air to the amount of steam at which condensation would occur at a given temperature and pressure. Relative humidity is expressed as a percentage – 0% means dry air, 100% means air completely saturated with water vapor. At a relative humidity of 100%, cooling of the air will cause condensation of water vapor. A close relationship with relative humidity has the so-called dew point (graph on the right). Knowing that at a temperature of 14°C the air can contain a maximum of 12g of water (dew point), we easily calculate that air with a relative humidity of 40% at the same temperature contains 4.8g of it.
