電動調節(jié)閥的調整與切斷控制一直是自動化生產(chǎn)控制中的難題,高溫切斷更加困難。主要表現(xiàn)為高溫膨脹引起的堵塞和斷流。所以調整器的高溫控制一直是廠家和設計單位關注的重。應怎樣選擇高溫電動調節(jié)閥?
The adjustment and cut-off control of electric control valve has always been a difficult problem in automatic production control, and it is more difficult to cut off at high temperature. It is mainly characterized by blockage and cut-off caused by high temperature expansion. Therefore, the high temperature control of regulator has always been the focus of manufacturers and design units. How to select high temperature electric control valve?
一、電動調節(jié)閥閥體及閥內件的材料選擇
1、 Material selection of valve body and trim of electric control valve
當閥門溫度大于450℃時,可以使用普通材料制成的電子控制閥,其溫度約為50℃。通常538℃以上是以鉻為主要用途。在1035℃左右的高溫下,通常采用SUS310S不銹鋼,因此材樣中的碳含量需要控制在0.04-0.08。于更高的溫度,建議使用非金屬耐熱材料(在1200℃下使用)或特殊的高溫高強度合金(在1000℃下可直接使用高溫高強度合金,如發(fā)動機燃燒室中的高溫高強度合金)。
When the valve temperature is greater than 450 ℃, the electronic control valve made of ordinary materials can be used, and its temperature is about 50 ℃. Generally, chromium is the main use above 538 ℃. SUS310S stainless steel is usually used at a high temperature of about 1035 ℃, so the carbon content in the material sample needs to be controlled at 0.04-0.08. For higher temperatures, it is recommended to use non-metallic heat-resistant materials (used at 1200 ℃) or special high-temperature and high-strength alloys (high-temperature and high-strength alloys can be directly used at 1000 ℃, such as high-temperature and high-strength alloys in engine combustion chambers).
二、電動調節(jié)閥填料耐高溫
2、 High temperature resistance of electric control valve packing
聚四氟乙烯標準填料只能在低于20O℃的溫度下使用。如需在中高溫環(huán)境下使用,需要使用延長閥蓋,以防止填料受高溫環(huán)境影響。但更長更細勺閥桿高溫下強度較低,高溫易彎曲。因此,在高溫下應采用耐溫性好的彈性石墨填料(60℃),可大大降低延長閥蓋高度。與此同時,采用“旋轉閥+粗閥桿”的方式,提高了閥門的整流強度,使問題得到較好的。
Teflon standard packing can only be used at temperatures lower than 20O ℃. If it needs to be used in medium and high temperature environment, it is necessary to use extended bonnet to prevent the packing from being affected by high temperature environment. However, the longer and finer spoon stem has low strength at high temperature and is easy to bend at high temperature. Therefore, elastic graphite packing with good temperature resistance (60 ℃) should be used at high temperature, which can greatly reduce and extend the height of the bonnet. At the same time, the way of "rotary valve + thick valve stem" is adopted to improve the rectification strength of the valve and better solve the problem.
三、電動調節(jié)閥密封方式的選擇
3、 Selection of sealing mode of electric control valve
由于在高溫下難以獲得較高的切削性能,傳統(tǒng)的高性能密封方法大多不適用,如O型環(huán)、四氟乙烯材料、彈性材料等。如果溫度低于50℃,則可采用異形復合石墨聞座軟封。如果超過50NC,只能使用金屬對金屬的硬密封(如蝶閥結構)。
Because it is difficult to obtain high cutting performance at high temperature, most of the traditional high-performance sealing methods are not applicable, such as O-ring, tetrafluoroethylene material, elastic material and so on. If the temperature is lower than 50 ℃, special-shaped composite graphite can be used for soft sealing. If it exceeds 50nc, only metal to metal hard seal (such as butterfly valve structure) can be used.
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