以超音波震盪技術處理溫泉碳酸鹽結垢之可行性研究

The Feasibility Study of Ultrasound Assisted Decarbonating Process for Scaling Problem in Hot Spring Water

台灣溫泉質可分為三類，分別以氯離子為主之氯化物泉、碳酸氫根離子為主之碳酸鹽泉、以及硫酸根離子為主之硫酸鹽泉。當上述幾種類型之溫泉水在管線輸送途中，以含碳酸氫根離子成份之泉質易附著及沉積於管線設備中，形成管線結垢之現象，此一問題長久以來深深困擾著一些溫泉業者。因此，為根本解決溫泉輸送管線及設備結垢之問題，本研究旨在研究及探討以模擬溫泉水樣通過尖端式超音波震盪器處理後，觀察循環系統中水樣之pH值變化及分析反應前後鈣離子之濃度，以驗證溫泉水中碳酸鈣結垢物之生成機制及超音波震盪處理後之抑制結垢效應。模擬溫泉水樣結垢機制之分析結果顯示，當循環系統於低流速時，陰陽離子問有較穩定之接觸作用，使其結垢物生成較穩定，較易產生結垢及沉澱之現象，反應後鈣離子濃度較低；然而，當流速增加時，因水中之擾動頻率增加，離子間失去穩定的生成機制，因而降低結垢物生成之機率，故呈現反應後鈣離子濃度較高之結果。此外，模擬溫泉水樣因受到高溫之影響，水樣中陰陽離子易以離子型態存在，可減緩結垢物生成及沉澱之時間。實驗結果與實地查訪時觀察之結果相互符合。因此，當溫度越高時，溫泉水體較不易出現結垢物之沉澱現象。超音波物理震盪效應抑制結垢物生成之結果顯示，超音波震盪處理系統適合於環境參數在低溫及低流速時，其物理性震盪效應可增加陰陽離子以離子態存在，因而產生穩定之抑制機制。因此，本研究所使用之超音波功率及頻率，受溫度及流速之影響，其震盪處理效應於低溫及低流速下較具抑制成效；然於高溫及高流速狀態時，其抑制效益較不明顯，此項結論仍需持續之研究及探討。

There were three types of hot spring water in Taiwan, including chlorine, carbonate and sulfate salt types. When the hot spring water was transported by pipeline system, the carbonate was easily precipitated in the interior of pipeline and storage tank, which considered as an essential problem for the hot spring industry. The huge maintenance cost and the produce of wasted pipes were considered as an environmental problem. Therefore, to solve scaling problems with green technologies, ultrasound energy was studied to the simulation process of hot spring transportation system. The hot spring scaling formation mechanisms and the performance of ultrasound inhibition process were studied basing on the changes of pH values and calcium ion concentrations. The experimental results indicated that the cations and anions were easily collided to form the precipitations under the low recirculation flow rate and the calcium were maintained in low concentration. Inversely, in high recirculation flow rate the calcium ion existed in higher concentration. When the temperature change in hot spring recirculation system, similar variation trends affected with flow rate also found. Higher temperature in spring water resulted in higher calcium concentrations remained. Thus, low flow rate and temperature could form a stable cations and anions collision reaction in hot spring water which resulted in high opportunity of scaling problems. The results indicated that scaling inhibition with ultrasound was depended on water flow rate and temperature. When the control system was under lower spring water flow rate and temperature, the performance of scaling problem inhibition was well. However, the performance was not obvious under higher water flow rate and temperature. The experimental results of this study are insufficient to conclude the optimization control conditions of ultrasound assisted inhibition process, which needs further researches and studies to fulfill the requirements.