Hydrogen Inhibition as Explosion Prevention in Wet Metal Dust Removal Systems

Hydrogen energy attracts an amount of attention as an environmentally friendly and sustainable energy source. However, hydrogen is also flammable. Hydrogen fires and explosions might occur in wet-dust-removal systems if accumulated aluminum dust reacts with water. Hydrogen inhibition is a safe method to address these issues. For this purpose, we used sodium citrate, a renewable and nontoxic raw material to inhibit H2 formation. Specifically, hydrogen inhibition experiments with sodium citrate were carried out using custom-built equipment developed by our research group. When the concentration of sodium citrate solution was in the range of 0.4–4.0 g/L, a protective coating was formed on the surface of the Al particles, which prevented them from contacting with water. The inhibitory effect was achieved when the concentration of sodium citrate was in a certain range, and too much or too little addition may reduce the inhibitory effect. In this paper, we also discuss the economic aspects of H2 inhibition with this method because it offers excellent safety advantages and could be incorporated on a large scale. Such an intrinsic safety design of H2 inhibition to control explosions in wet-dust-removal systems could be applied to ensure the safety of other systems, such as nuclear reactors.

Using sodium D-gluconate to suppress hydrogen production in wet aluminium waste dust collection systems

The reaction of aluminium dust and water generated in the production of aluminium products generates hydrogen, which poses a risk to wet collection systems for hydrogen explosions. In this paper, non-toxic and environmentally friendly sodium D-gluconate is used to suppress the hydrogen production reaction of aluminium waste dust and water. The results of the hydrogen evolution curves and chemical kinetics of 7 different concentrations of sodium D-gluconate showed that when the sodium D-gluconate concentration reached 0.25 g L^-1, there was almost no hydrogen generation, and the rate constant was almost zero. The scanning electron microscopy (SEM) results showed that the surface of the reaction product became smoother with increasing solution concentration. The energy dispersive spectroscopy (EDS) results showed that increasing the solution concentration slowed the formation of aluminium oxide in the product, confirming the effectiveness of sodium D-gluconate in inhibiting the reaction of aluminium waste dust particles with water. The Fourier transform infrared (FTIR) results showed that sodium D-gluconate formed a chemical adsorption film on the surface of aluminium waste dust particles to prevent the dust from contacting water, thus suppressing hydrogen production. This method provides a new approach to design safe wet collection systems by suppressing hydrogen production.

Application and Research of Swirling Curtain Dust Collection Technology in Mines

During the production process in mines, large amounts of dusts are produced. The dusts pose a potential hazard to the health and safety of miners. Traditional dust removal methods, such as ventilation, water sprays and foam technology, cannot completely solve the problem of dust pollution, due to low efficiency or high consumption of water or large resistance (>2000 Pa). Therefore, a swirling curtain dust collector (SCDC) was proposed to collect the dust in mines. The device was combined swirling atomization with spray curtain for dust removal. The performance of SCDC was investigated. According to the results, the optimum working condition of the device was: air pressure: 0.35 MPa, water volume: 30 L/h; liquid–gas ratio: 0.15 L/m3; air speed: 14–16 m/s. Under these operation parameters, the suppression efficiency of total dust and respirable dust were over 99.8% and 97%. The proposed device was applied at transfer stations of Luohe Metal Mine in Anhui, China. The application results showed that the dust concentration at the outlet of SCDC in the transfer station is lower than 20 mg/m3, which is stipulated by Chinese standard GB 28661-2012. The proposed device is expected to replace the traditional Venturi wet scrubber in mines.

Study of hydrogen explosion control measures by using l-phenylalanine for aluminum wet dust removal systems

The reaction between aluminium dust and water in wet dust removal system is inhibited by using l-phenylalanine.