• Technical engines

    for pure water

Water treatment

Under German Work-place Ordinance and German Industrial Safety Ordinance, operators are responsible for the hygienic operation of an air humidifier.

VDI 6022 and the operating instructions for the air humidifier provide important information in this regard. These stipulate that air humidifiers must be operated, in principle, in a way that prevents any growth of microorganisms.

The wet areas within the air humidifier encourage microbial proliferation.

To prevent the total colony count increasing above the limit value set out in VDI 6022, we recommend water sterilisation in addition to regular cleaning.
Adherence to hygiene requirements must be ensured and recorded by means of regular reviews (hygiene controls/ inspections).

To ensure hygienic operation, special requirements are therefore placed on the system components and maintenance measures:
  1. Supplied water must meet the microbiological requirements of the German Drinking Water Ordinance
  2. Good accessibility of areas exposed to water
  3. In the event of extended shutdown phases (>48h), the humidifier tank including all water-bearing components must be completely drained. Systems with an effective sterilisation unit are exempt from this regulation
  4. The total colony count in the humidifier water must be below 1,000 CFU/ml
The following systems, which can also be used in combination depending on bacterial load of the supply air, are available: Blowdown, physical water sterilisation and chemical water sterilisation

Manual/automatic blowdown

Circulating water spray humidifiers (air washers) experience thickening of the circulating water due to water evaporation and dirt particle washout. This concentration of foreign substances needs to be periodically counterbalanced by blowdown devices to prevent malfunction and excessive contamination. Manual blowdown is therefore part of every LAVAIR air washer.

The desludged water flow is either set manually via a ball valve – manual blowdown – or controlled via a motor-driven ball valve in line with the measured conductivity – automatic blowdown. The advantage of the automated mode is that it provides blowdown rate as needed. Fluctuations in humidifier capacity and contaminant input are reliably levelled out, thereby maintaining consistent water quality.

UV immersion emitters

The UV immersion lamps are installed directly underwater within the humidifier tank. This means that the complete tank contents are simultaneously sterilised. Depending on tank size, a variable number of immersion lamps are installed to obtain the best possible effect.

UV reactor

The external UV sterilisation unit consists of a stainless steel UV reactor with an internal UV lamp, an electronic monitoring unit, a UV sensor and a pressure or flow switch. A recirculating pump is used to suck the water from the tank, pump it through the reactor and then channel it back to the tank. The monitoring unit measures the UV radiation strength and the lamp’s runtime, outputting an alarm signal if the maximum runtime is exceeded or if the radiation intensity falls below the minimum requirement.