R&D ACTIVITIES

AWS promotes the innovation, in which new ideas are generated and turned into business opportunities. Qualified and experienced engineers develop innovative solutions that are adapted to our customers.

Our equipped R&D facility and the collaboration of the Department of Chemical Engineering, University of Pisa and Milano, enable us to carry out tests and feasibility studies.

PROJECT APC004 : NEW WESP GENERATION WITH HIGH CONDUCTIVE FRP

Abstract

Dust removal from flue gases has been studied in an pilot scale Wet Electrostatic Precipitator (WESP), which is integrated in a scrubber and equipped with a water cooled condensing collector fabricated in conductive fibre reinforced plastic (FRP). The conductive FRP collector showed no signs of influence from 10 weeks of continuous operation. The high frequency transformer operated WESP unit was found to be more energy efficient than the other studied dust removal devices. Dust measurements and real time particle size distribution measurements showed removal efficiencies of typically > 99% and downstream dust concentrations below 0.3 mg/Nm3 dg. equal to 3% of the applicable emission limit.

Background

A high concentration of submicron particles in the ambient air, often referred to asPM2.5(Particulate Matter,i.e. particles < 2.5 µm), leads to an enhanced health risk and causes premature death of 350 000 EU citizens per year. In many urban environments, the ambient air levels of PM2.5 are higher than stipulated by EU directives 1999/30/EC and 96/62/EC.Combustion processes for heat and power production is an important source of PM2.5 emissions. To meet future requirements of economical and robust dust cleaning equipment, more research work is needed in this area.

The aim of this work is to demonstrate a new scrubber integrated, cylindrical WESP (Wet Electrostatic Precipitator),fabricated in conductive FRP (Fibre Reinforced Plastic). It is furthermore equipped with a water cooled condensing collector and a high frequency transformer.

Measurement methods

Concentrations of particles in the gas into (Cin) and out from WESP (Cout) have been measured with the aim to calculate the dust removal efficiency η:

The mass concentration of particles has been measured using the European dust measurement standard method EN 13284-1. It means isokinetic sampling with a heated probe (100-120 °C) and associated heated filter. Chemical analyses were conducted on the dust upstream of the WESP unit. The following elements were analysed: Al, Ba, Ca, Fe, Mg, Mn, P, Si, Zn, Na, K, Ti, Cu, Pb och Li, sulphate, Cland Br. The mass size distribution (0,030-10 µm) of particles were measured using a low pressure impactor. On-line-measurement of number concentration and size distribution (0,007-7 µm) was performed using two ELPI (Electrical Low Pressure Impactor). The temperature of the flue gas had to be below 40 °C during the measurements. To meet this requirement and to avoid condensing in the sampling system during measurement, a sampling system according to Figure III was set up. The principle used was heating of the probe, dilution air and diluter and thereafter the flue gas is cooled down by passing through a transparent Tygon hose.

 

Results

The concentration of dust upstream of the WESP unit varied between 6.2 and 28 mg/Nm3 dry gas.All measured outlet dust concentrations were below 0.3 mg/Nm3 (dry gas., 11% O2) as shown in Table I. This equals 3% of the applicable emission limit. The dust removal efficiency has been higher than 97% in all the measurements. The mean concentration for all the dust measurements was 15.2 mg/Nm3 upstream and 0.14 mg/Nm3 in downstream (both as dry gas, 11% O2), which gives an average removal efficiency of slightly more than 99%. The removal efficiency increased with increasing inlet dust concentration, SO2 concentration and ΔT of the collector cooling. Chlorine, potassium, sodium, silicon and sulphur dominated the composition of the dust.

 

PROJECT ASMS003 : NEW FIBERWIND MIST ELIMINATORS

FIBERWINDTM pilot system

  • high flexibility
  • particles analysis system

R&D 's objective: new types of FIBERWINDTM to lower pressure drop and / or to higher rate of filtration.

PROJECT WWTP001 : ADVANCED WASTE WATER TREATMENT

CONFIDENTIAL

PROJECT ASMS002 : NEW TIDEVANE MIST ELIMINATOR

TIDEVANETM collection mechanism

TIDEVANETM mist eliminators are inertial separators because liquid droplets are removed due to their inertial momentum. Good removal efficiency when the mass of the droplets to be removed is in the range of 10 micron and larger. Below 10 micron they still show reasonable efficiency which is higher, the higher is the face gas velocity.

TIDEVANETM mist eliminators have an high resistance to fouling, they can work in presence of sticky or insoluble solids.

TIDEVANETM pilot system

R&D 's objective: new types of TIDEVANETM to lower pressure drop and remove high liquid amounts combined with high gas flow rates.