【a brief introdction】
Chu Yi vehicle urea solution concentration online detection sensor adopts the principle of critical angle detection, directly installed on the pipeline or the tank, and measures the change of vehicle urea concentration at any time. The measured value is transmitted to the PLC or DCS, which is adjusted by PID to accurately output the valve The bit signal controls the amount of make-up water to ensure a constant urea solution concentration. The detection is not affected by the color, turbidity, bubbles, solid particles and other impurities of the material, and it has a high-precision automatic temperature compensation function.
F （DieselExhaustFluid，即柴油机尾气处理液） ， 柴油机尾气处理液(国内俗称为: 汽车尿素 ， 车用尿素 ，汽车环保尿素)，是 SCR 技术中必须要用到的消耗品。 The urea solution for vehicles was first called Adblue in Europe, and DE F (DieselExhaustFluid, diesel exhaust gas treatment fluid) in North America . Diesel exhaust gas treatment fluid (commonly known in China: automotive urea , automotive urea , automotive environmentally friendly urea), is SCR Consumables must be used in technology. ， 用于还原氮氧化合物 。 The urea solution for vehicles is a colorless, transparent and clear liquid with a concentration between 31.8% and 33.2%. It is composed of 32.5% high-purity urea and 67.5% deionized water for reducing nitrogen oxides . 使用尿素浓度为32.5%的尿素水溶液作为复原剂, 是 因为此浓度的车用尿素溶液结晶点最低(初始结晶点-irc)。 Diesel vehicles use a urea solution with a urea concentration of 32.5% as a reconstituting agent because the urea solution of this concentration has the lowest crystallization point (initial crystallization point -irc). Vehicle urea equipment manufacturers need to take insulation measures if the urea solution for vehicles is operated below -irc. The urea solution for vehicles will begin to freeze at -11 ° C. In actual use, it will completely freeze at -20 ° C. The current technology is to prevent the solution from solidifying by adding modifiers to lower the freezing point of the solution and adding a heating device.
Domestic urea for vehicles is mainly purified from industrial urea. Its main principles are: 1) At a temperature of 70-75 ° C, urea is hydrolyzed in an aqueous solution. 2) When the temperature is below 30 ° C, urea is recrystallized from the aqueous solution. 3) The purity will be greatly improved after each hydrolysis and crystallization. Generally, the industrial urea is used to hydrolyze and crystallize once to reach the standard of urea for vehicles. The output ratio is 1.5: 1. Because the SCR catalyst carrier of automotive urea is prone to metal ion poisoning and loses its catalytic effect, the automotive urea solution must use first-class ultrapure water (resistivity ≥18MΩ? Cm) in the electronics industry.
Pure water process:
Raw water → raw water tank → booster pump → sand filter → activated carbon filter → scale inhibitor device → 5μ precision filter → first stage high pressure pump → first stage membrane treatment system → first stage RO tank → second stage high pressure pump → second stage Membrane treatment system → Secondary RO water tank
Urea production process
Tap water → pretreatment → primary reverse osmosis → secondary reverse osmosis → ultrapure water storage tank → material storage tank → homogenization system → primary filtration system → decolorization system → extraction → purification → filling
采用临界角检测原理， 直接安装于管路上或槽体上，随时测量 车用尿素 浓度的变化，测量值传送到 PLC或 DCS ， 通过PID调节，精确输出阀位信号控制补给水量，保证 尿素液 的浓度恒定 。 Chuyi vehicle urea solution concentration online detection sensor adopts the principle of critical angle detection, directly installed on the pipeline or tank, and measures the change of vehicle urea concentration at any time . The measured value is transmitted to PLC or DCS , which is adjusted by PID to accurately output the valve. The bit signal controls the amount of make-up water to ensure a constant urea solution concentration . The detection is not affected by the color, turbidity, bubbles, solid particles and other impurities of the material, and it has a high-precision automatic temperature compensation function. Adopting excellent split design, fully shielded anti-interference design, direct conversion processing of photoelectric signals. Discard the shortcomings of integrated intolerance of vibration and high temperature, ensure the accuracy of online measurement and extend the service life of the instrument. ， 传感器由：蓝宝石棱镜（9个摩氏）、内置PT1000温度传感器、长寿命LED光源（10000h）、3648像素分辨率 的 传感器组成。 The built-in optical fiber optical path transmission system has excellent shock resistance and high stability . The sensor consists of: a sapphire prism (9 Mohs), a built-in PT1000 temperature sensor, a long-life LED light source (10000h), and a sensor with 3648 pixel resolution .
，测量 速度快、准确，精度0.1% 。 Chu Yi car's urea solution concentration online detection sensor , no consumables, no maintenance, no drift , fast and accurate measurement, accuracy of 0.1% . 操作简单方便、维护量少、工作可靠 ， 可减轻维护人员的工作量。 The automatic cleaning and cleaning system of the instrument automatically cleans the prism and self-diagnostic function to eliminate faults in a timely manner. The operation is simple and convenient, the maintenance is small, and the work is reliable , which can reduce the workload of the maintenance staff. The fully-cast glass fiber reinforced plastic shell and the fully shielded steel plate inner wall design ensure that the instrument can run smoothly under any harsh working conditions.