ABSTRACT
Natural gas generates varying concentrations of H2S during natural formation and extraction, and H2S leak accidents are frequent, posing a significant threat to the safety of human life and the environment. Conventional treatment technology equipment is large and does not meet the emergency requirements of the complex topographical gas field. This study aimed to design a pilot-scale method coupling the venturi and bubbling reactors to reduce equipment size and improve emergency capabilities for the absorption of leaked H2S. It found that the ring system self-priming venturi reactor, which was suitable only for the coarse treatment of toxic gases, maintained an absorption efficiency of around 50% under most operating conditions, with substantial variations due to changes in process parameters, but that redundancy of the bubbling reactor was high. With the synergistic effect of venturi and bubbling, the coupling process had an extremely high absorption efficiency, basically more than 95%. The experiments also showed that the H2S concentration at the outlet of the venturi-bubbling reactor increased with increasing inlet gas concentration and gas volume. The absorption performance improved significantly on increasing Fe3+ concentration; it increased first and then remained constant, and the optimum Fe3+ concentration for the absorption of leaked H2S was 21â¯000 mg/m3. The absorption performance decreased with increasing submergence height and then remained stable after the size of the inlet approached 600 mm, whereas the overall absorption efficiency of the venturi-bubbling reactor remained constant. The optimum operating temperature range was 10 °C-50 °C. The experimental system kept the outlet concentration below the emergency discharge standard for a continuous period of 48 h following practical use in the gas field and resulting in significant enhancement in mass transfer performance, fully satisfying the emergency requirements.
ABSTRACT
<p><b>OBJECTIVE</b>To probe into the mechanism of pneumothorax caused by acupuncture or acupoint injection and the preventive methods.</p><p><b>METHODS</b>Retrospectively analyze the clinical original symptoms of 38 cases with pneumothorax caused by acupuncture and acupoint injection, which were divided into four clinical types: dyspnea type, shock type, thoracalgia type and tardy type. Illustrate the relation of the clinical types with severe degrees of pneumothorax, and the mechanism of pneumothorax inducing death of the patient.</p><p><b>RESULTS</b>In the series there were 38 cases with pneumothorax induced by acupuncture or acupoint injection, including 4 cases of dyspnea type, 16 cases of shock type, 14 cases of thoracalgia type, 4 cases of tardy type. After proper treatment, 37 cases were cured and one case of dyspnea type died of tension pneumothorax.</p><p><b>CONCLUSION</b>The mechanism of pneumothorax caused by acupuncture or acupoint injection is that due to the filiform needle tip or the syringe's needle tip inserting into the lung tissue at the patient's respiration in acupuncture or acupoint injection, the filiform needle tip or the syringe's needle tip lacerates the lung tissue. Air in alveolus goes into the thorax pleura cavity to form pneumothorax. In acupuncture or acupoint injection, the needle tip must not insert into the lung tissue, which is a key for prevention of pneumothorax.</p>
