Odor scrubber for fragrances and flavors

A custom-made vertical scrubber for a gas flow of 8,500 Nm3/h made of PP which is specially configured with a diameter of 1,600 mm and a height of 6,500 mm.

The scrubber works according to a so-called closed loop system in which the washing section consists of an open spray system. The scrubber has removable spray lances equipped with tangential spray nozzles divided into two sections, an agglomerator, dividing redistributor plate and a wire mesh demister.

Process description

• Alkaline wash section with caustic soda (NaOH) solution. The dosage of caustic soda will have to be based on the pH. The washing section is equipped with an inspection hatch. The washing section consists of spray nozzles which are mounted co-current and counter current. The blockage-free tangential spray nozzles create fine droplets to capture as many dust/gas particles as possible. The section is constructed in such a way that the nozzles, due to their joint large flow rate, rinse the inside of the washing section well at the same time. The nozzles are mounted with an overlapping spray image on several spray pipes in succession, creating a very intensive cleaning system. This means that the contaminated gas cannot pass through the spray section without being moistened and cleaned. As a result, packings are completely unnecessary, so that the pressure loss is exceptionally low and, above all, remains low. The chemicals can be dosed in the buffer tank, where the conductivity of the washing water must also be measured. Based on these measured values, it can then be automatically sprayed and supplemented from the second (neutral section) and then the required amount of caustic soda can be dosed in the scrubber.
• The pre-separator/ agglomerator is intended to separate the coarse droplets and relieve the wire mesh demister. It could clog or become overloaded without a pre-separator/ agglomerator. In addition, this separator also functions as an agglomerator, which means that the fine droplets that are normally inseparable are agglomerated. Small droplets coagulate into large(er); this allows the wire mesh demister to function optimally.
• The separation soil prevents washing water from the second section from running directly back to the first alkaline section.
• Above the separation bottom, again counter-current spraying nozzles have been mounted for a second wash.

Finally a wire mesh demister functions as a fine separator with a high degree of separation and a low pressure loss.