三组换向阀与RT0三个蓄热室对应，通过一定的顺序打开、关闭，引导烟气通过蓄热室、燃烧室，最终排放到大气中。工作时RTO焚烧炉内呈微负压状态。高温侧换向阀的外侧与烟气出口管道连通，区域温度最高达300°C;低温侧换向阀的外侧与烟气进口管道连通，区域温度最高达200°C。炉内废气具有一定的腐蚀性。装置运行时，换向阀每60-180s开闭一次，动作频繁。

Three sets of directional valves correspond to the three heat storage chambers of RT0, which are opened and closed in a certain order to guide the flue gas through the heat storage chamber and combustion chamber, and finally discharged into the atmosphere. During operation, the RTO incinerator is in a slightly negative pressure state. The outer side of the high-temperature side directional valve is connected to the flue gas outlet pipeline, with a maximum temperature of 300 ° C in the area; the outer side of the low-temperature side directional valve is connected to the flue gas inlet pipeline, with a maximum temperature of 200 ° C. The exhaust gas in the furnace has a certain degree of corrosiveness. During device operation, the directional valve opens and closes frequently every 60-180 seconds.

换向阀的平面阀板与密封端面通过直接接触实现密封。阀板闭合后，因加工、装配精度低导致密封不严，废气在压力作用下流动，在阀板处形成少许内漏，不通过蓄热体及炉瞠焚烧直接排放。同时，阀杆在往复运动中对密封填料造成磨损，使废气通过填料直接泄漏到大气中，发生外漏。

The flat valve plate of the directional valve is sealed by direct contact with the sealing end face. After the valve plate is closed, the sealing is not tight due to low processing and assembly accuracy, and the exhaust gas flows under pressure, forming a small internal leakage at the valve plate, which is directly discharged without passing through the heat storage body and furnace combustion. At the same time, the valve stem causes wear on the sealing packing during reciprocating motion, causing exhaust gas to leak directly into the atmosphere through the packing, resulting in external leakage.

另外，换向阀内部存在高温烟气，经长期运行后，原阀杆与阀板均存在不同程度的腐蚀损坏。由于原换向阀设计存在上述问题，加之在排放指标、环保指标更为严格的情况下，即使少量的泄漏也会对排放指标产生很大的影响，因此需要通过改造提高阀门的密封性、耐蚀性和耐用度，使装置能够满足现有工况条件下长期稳定运行的要求，并且使排放的废气满足《GB31571-2015石油化学工业污染物排放标准》的排放指标。

In addition, there is high-temperature flue gas inside the directional valve, and after long-term operation, the original valve stem and valve plate have varying degrees of corrosion damage. Due to the aforementioned issues with the original directional valve design and the stricter emission and environmental standards, even a small amount of leakage can have a significant impact on the emission indicators. Therefore, it is necessary to improve the sealing, corrosion resistance, and durability of the valve through modification, so that the device can meet the requirements of long-term stable operation under existing working conditions, and the emitted exhaust gas can meet the emission indicators of the "GB31571-2015 Petrochemical Industry Pollutant Emission Standard".

根据长期运行后装置换向阀出现的泄露、损坏等问题，结合故障点的出现位置，可以从以下三个方面对换向阀的结构进行分析，并考虑改进办法:

Based on the leakage and damage of the reversing valve after long-term operation, combined with the location of the fault point, the structure of the reversing valve can be analyzed from the following three aspects and improvement methods can be considered:

1.阀杆材料及其连接结构换向阀的主要动件是阀杆和圆形阀板，因阀门动作频繁，密封结构及支撑结构负荷较大。加之炉中废气温度较高且有较强的腐蚀性，装置运行一段时间后，阀杆与阀板均发生了一定的磨损与破坏。

The main moving parts of a directional valve are the valve stem and circular valve plate. Due to frequent valve movements, the sealing and supporting structures are heavily loaded. In addition, the exhaust gas in the furnace has a high temperature and strong corrosiveness, and after running the device for a period of time, both the valve stem and valve plate have suffered certain wear and damage.

经现场测量、检查发现，阀板与密封面之间存在一定程度的平行度偏差。因此，应对阀板与阀杆采取降低重量、更换材料、增加错动补偿机构等措施使动件拥有更长的使用寿命和更好的密封效果。

After on-site measurement and inspection, it was found that there is a certain degree of parallelism deviation between the valve plate and the sealing surface. Therefore, measures such as reducing weight, replacing materials, and adding misalignment compensation mechanisms should be taken for the valve plate and stem to ensure that the moving parts have a longer service life and better sealing effect.

2.阀板密封结构原设计中，圆形阀板仅通过与密封面接触时自身发生形变来进行密封。

In the original design of the valve plate sealing structure, the circular valve plate only seals by deforming itself when in contact with the sealing surface.

由于加工精度无法保证，以及长期运行带来的支撑结构磨损，圆形阀板与密封面无法在圆周上所有的位置都能紧密接触。因此，需要对阀板密封结构进行重新设计，来保证长期运行中阀板密封的可靠性。

Due to the inability to guarantee machining accuracy and the wear of supporting structures caused by long-term operation, the circular valve plate and sealing surface cannot be in close contact at all positions on the circumference. Therefore, it is necessary to redesign the valve plate sealing structure to ensure the reliability of valve plate sealing during long-term operation.

3.阀杆密封结构及支撑结构原设计中，阀杆的密封组件采用的是填料式密封，由于换向阀的动作频率非常高(每60-180s动作1次)使得此处密封填料的损耗非常快。

In the original design of the valve stem sealing structure and support structure, the sealing component of the valve stem used a packing type seal. Due to the high operating frequency of the directional valve (once every 60-180s), the loss of sealing packing in this area is very fast.