Cases study

Pet food industry: odour reduction by means of an osmogenic barrier

Using nebulization systems and specific neutralizing products, we solved a problem of bad odour emission coming from the premises a company producing pet food

Field of activity

Food processing industry

Activity

Pet food production

Location

Central Italy

Critical emissions

Unpleasant odours deriving from various processes

Service supplied by Labiotest

Design and installation of an osmogenic barrier equipment

Critical emissions of the pet food facility

In companies that produce animal food, problems due to smelly emissions often occur.

Generally, these odours are due to the processing of raw materials used to obtain the finished product, as in the case of an industry in central Italy that contacted us for a problem with odorous emissions generated during three specific processing phases: extrusion, drying and cooling.

Pet food processes causing smells

Let us have a look at some details, which these three phases consist of.

Extrusion

The product goes through a cooking process ensuring a reduction of the bacterial load, to make it safe from a microbiological point of view due to temperature (above 100°C) and pressure (between 20 and 40 bar as an average).

Limited to the production of fresh meat sticks, extrusion is a cold process, which allows shaping meat cords to cut be by means of a special cutter, before they are sent to the cooking oven.

Drying

A methane or steam dryer ensures temperatures that allow the evaporation and removal of excess water absorbed by the product in previous phases, if the process time is adequate. In such a way, humidity decreases, which ensures more stability to the product.

In the production of fresh meat sticks, the drying production process takes place in a ventilated tunnel oven. In this case, drying coincides with the slow cooking of the product at a low temperature (about 70°C for 4 hours).

Cooling

Cooling products with a forced airflow at room temperature helps avoiding condensation in the subsequent storage phase, while ensuring more product stability over time.

Seven emission points

Our client's critical emission points, due to the three above-mentioned production phases, were seven as a whole:

  • 2 dryers/extruders with cyclone abatement
  • 1 dryer exhaust suction system
  • 1 extrusion system with cyclone abatement
  • 2 vertical coolers - extruders with cyclone abatement
  • 1 horizontal cooler - extruder with cyclone abatement.

Specifically designed nebulization system

After examining the situation and the data provided by the client regarding effluents to be treated, our technicians developed a customized project to deal with critical emissions.

We used the plenum as a calming chamber to obtain optimal conditions as regards air speed and therefore guarantee the contact time necessary for our neutralizing product LT Air Plus, diluted at an optimal concentration, to ensure its best possible performances in order to reduce odour concentration.

In the lower part inside the calming chamber, six stainless steel bars were set up, each equipped with five spraying nozzles.

Two additional bars were positioned in the upper part of the plenum. The whole unit is handled by a nebulization system called HPS Midi Plus.

Abatement results obtained

Using our osmogenic barrier, the client obtained a significant improvement in odorous criticalities, also demonstrated by olfactometric investigations that detected a reduction in odor concentration equal to 78%.

The customer has signed a total maintenance contract.