化學存儲Monitoring

On a recent visit to evaluate several level transmitters on chemical storage applications at a new combined cycle power plant, we had the opportunity to work with the EPC firm, plant personnel and the chemical supplier. This provided an interesting look at the level instrumentation package for the chemical storage side of things from an engineering perspective, as well as from a daily operations point of view.

氨，酸和腐蝕性化學儲存

雖然重要的測量，氨，酸和腐蝕罐是磁離子的難度水平應用^®and Orion Instruments^®by any stretch. However, we found that small nuances on how the applications are monitored relative to technology can have a dramatic effect on the day-to-day practicality and reliability of the type of instrument(s) used. Additionally, there are safety considerations when replenishing these chemicals, which can be addressed simultaneously with inventory monitoring by implementing a few simple, cost-effective modifications to the instrumentation package.

這些化學儲罐可以是水平或垂直血管直徑/高度六至10英尺，氨儲罐通常是三個中最大的。看到某種類型的非接觸電平發射器（超聲波是最普遍的）並不罕見，以便在罐底部的局部顯示器向控製室提供電平指示，其中串聯與4-20 mA係列發射器輸出或從控製室重複。控製室的信號跟蹤庫存，充當溢出保護的高報警，並建立再補給間隔。本地顯示有助於監控供應商的卡車的化學物質的卸載。

您可以在這些應用程序中拋出許多級別技術。我們的偏好是酸和苛性罐中的通過空氣（非接觸式）雷達或導向波（接觸）雷達，以及氨儲存的後者。這並不意味著非接觸式超聲波變送器或其他技術不達到任務。簡而言之，雷達對整個當前血管的蒸氣空間內容的變化漠不關心。通常，這些變化會影響超聲波突發，導致我們稱為滋擾警報，例如，它間歇地失去信號，或者級別的指示隻能恢複技術人員到達場景時的時間不穩定。這些類型的問題難以隔離，因為它們是間歇性的，並且與儀器中的安裝或配置異常或硬故障無關。如果不需要校準的競爭性所需的技術，並且可以通過改變過程條件不受影響，我們將采取該路徑。雷達符合這三個標準。

來自I＆C團隊的績效觀點

討論與儀控技術和化學upplier during the evaluation process were confined to reliability, remote indication and performance verification of the level transmitter. Both preferred an independent visual indication along the lines of a Magnetic Level Indicator (MLI) on all three tanks. From the technician’s perspective it allows for easy verification of the level transmitter’s performance and adds a layer of redundancy in case the transmitter was out of commission for whatever reason. We have a lot of confidence in our instrumentation hitting the mark right out of the gate, but we have to admit it is nice to have a second opinion on the reading following initial commissioning. Sticking these tanks is usually not an option during normal operation.

Level Gauge Readability During Product Transfer

化學品供應商的洞察力專注於從卡車轉移到坦克的產品期間的可讀性。盡管他通常卸載船舶應在派遣之前的水平指示適應的固定數量的材料，但知道轉移過程中的水平是防止過度填充的安全措施。他的評論是，可以在管理其他任務的同時輕鬆地從一段距離輕易讀取MLI，而他必須在LCD型顯示頂部以監控進度。當使用氨儲罐時，這尤為重要。

Considerations When Top Filling

One item worth pointing out that would simplify the commissioning of the instrument is the close proximity of the top-fill piping to the instrument mounting nozzle on the smaller acid and caustic tanks. Since non-contact technologies are ubiquitous on these applications and rely on projecting a circular or elliptical signal footprint perpendicular to the surface of the material being measured, locating the instrument nozzle as far away from the turbulence generated while top filling is the ideal. Furthermore, such close proximity allows the spray pattern created as the chemical enters the vessel to interact with the transmitted beam, which could cause a loss of signal during the fill process leaving the supplier blind as to the remaining space in the vessel. Tweaking the instrument’s configuration to overcome such obstacles is possible with time and patience. On the flipside, separating these two entry points during the design phase of the vessels would eliminate any potential problems without adding cost or extending the commissioning time. The present nozzle/fill line configuration is another point to argue the case for an MLI or opting for Guided Wave Radar technology to eliminate any potential interference and excessive turbulence near the transmitter.

After surveying each application and visiting with the I&C department and chemical supplier, we reviewed the various options with the engineering team. Our collaboration yielded three options to improve the reliability and enhance the day-to-day functionality of the instrumentation package.

這種方法的另一個好處是在儀器噴嘴安裝位置相對於容器頂部填充管道布置的更具靈活性。引導波雷達是一種接觸測量，其傳感元件可以忽略湍流和先前提到的化學噴霧圖案。此增加的益處不僅簡化了儀器的調試，而且將測量與罐動力學分開以提高可靠性。

最後，我們看著包括一些“願望清單”項目，I＆C技術人員和化學品供應商指出並添加了視覺指示器（ORION Instruments atlas™或極光^®模型）用於水平驗證，冗餘和多樣化的測量技術以及正常植物操作期間的可讀性。即使考慮到在最小安裝中包含的外圍物品，此方法也會向儀表包添加成本。除了傳統上具有用於容納外部安裝裝置的工藝連接的氨儲罐，與酸和苛性罐添加類似的工藝連接也會達到容器的成本。在宏偉的事物方案中，與長期利益相比，額外的成本很小，但它需要考慮化學儲存監測。