Vacuum dynamic seal

在進行噴淋清洗或（huò）超聲（shēng）波浸漬清洗時（shí），工（gōng）件籃在電機帶動下旋轉，此時腔體（tǐ）內真空度為(5～8)kPa，為防止外部空氣進入真空腔（qiāng），需要在電機軸與腔體連接處進（jìn）行動密封，一般是采用機械（xiè）密封裝置，並在機械密封與旋轉軸之間、機械密封本體內均注入潤滑油達到動密封效果。

When performing spray cleaning or ultrasonic immersion cleaning, the workpiece basket rotates under the drive of the motor. At this time, the vacuum inside the cavity is (5-8) kPa. To prevent external air from entering the vacuum cavity, it is necessary to install a movable seal at the connection between the motor shaft and the cavity. Generally, a mechanical seal is used, and lubricating oil is injected between the mechanical seal and the rotating shaft, as well as into the mechanical seal body, to achieve the effect of dynamic sealing.

與常規動密封不一樣，碳氫設（shè）備動密封麵臨一個難題:隔離對象是空氣及（jí）碳氫溶劑（jì）。碳氫溶劑本身是可以溶解潤（rùn）滑油的，而且碳（tàn）氫溶劑表麵張力小，滲透力強，特別在超聲波作用下，對（duì）油脂的溶解效（xiào）果更加明顯，長時間的（de）運轉，是否會將潤滑油脂溶解掉而造成泄漏及旋轉（zhuǎn）幹磨。因（yīn）此，如何做好碳氫溶劑的（de）真空動密（mì）封是碳氫設備（bèi）研發的一（yī）個難點。

Unlike conventional dynamic seals, hydrocarbon equipment dynamic seals face a challenge: the isolation objects are air and hydrocarbon solvents. Hydrocarbon solvents themselves can dissolve lubricating oil, and their surface tension is small and their permeability is strong. Especially under the action of ultrasound, the dissolution effect of oil and grease is more obvious. Will long-term operation dissolve the lubricating oil and cause leakage and rotary dry grinding. Therefore, how to do a good job in vacuum dynamic sealing of hydrocarbon solvents is a difficulty in the development of hydrocarbon equipment.

溶劑回收

Solvent recovery

在進行（háng）溶劑真空蒸（zhēng）餾回收時（shí），蒸餾釜加熱產生的（de）蒸汽中包括（kuò）空氣、溶劑蒸（zhēng）汽、水蒸氣（qì），溶劑（jì）中含（hán）水會造成清洗零件的（de）氧（yǎng）化，因此需（xū）要大限度的降低（dī）水含量。碳氫（qīng）溶劑與水的分離一般（bān）有兩種方（fāng）式(假定在（zài）真空壓力p、溫度t1處進行蒸餾)。1)保持壓力，降低冷凝區溫度至t2，碳氫蒸汽先開始液化，保持t2一段時間，直到（dào）碳（tàn）氫蒸汽完全液化，剩餘氣體為（wéi）水氣及空氣。2)保持溫（wēn）度不變，降低真空度（dù），增（zēng）加冷凝區壓（yā）力，水蒸氣（qì）先開始液化，保持該真空度一定時間直到水氣完全液化，剩餘氣體為碳氫蒸汽及空氣。
 

When conducting solvent vacuum distillation recovery, the steam generated by heating the distillation kettle includes air, solvent steam, and water vapor. Water in the solvent can cause oxidation of the cleaned parts, so it is necessary to minimize the water content. There are generally two ways to separate hydrocarbon solvents from water (assuming distillation at vacuum pressure p and temperature t1). 1) Maintain pressure and lower the temperature of the condensation zone to t2. The hydrocarbon vapor begins to liquefy and remains at t2 for a period of time until the hydrocarbon vapor is completely liquefied, with the remaining gas being water and air. 2) Maintain the temperature unchanged, reduce the vacuum degree, increase the pressure in the condensation zone, and water vapor begins to liquefy. Maintain this vacuum degree for a certain period of time until the water vapor completely liquefies, and the remaining gas is hydrocarbon vapor and air.

安全性設計（jì）

Security design

1)防止泄漏。為防止泄漏(或在泄（xiè）漏時盡量減少泄漏量)，需要從多（duō）方進行考慮。一是在各腔體、各管（guǎn）係的適（shì）當位置均設置壓力檢測，所有的檢（jiǎn）測值均引入PLC，並與PLC內事先存儲的設定值進行比（bǐ）較（jiào），若（ruò）與設定（dìng）值差異很大，則（zé）關斷工作電源並報警;二是管係上（shàng）各（gè）主要（yào）器件之間均設置氣控閥，當其中一段（duàn）發生泄漏時，可將該段（duàn）兩端的氣控閥關閉，將泄漏量降到低（dī），三是氣控閥及控製氣閥的電磁閥均采（cǎi）常閉閥，確保斷電即斷氣，確保管係能分（fèn）段隔離。

1) Prevent leakage. To prevent leakage (or minimize the amount of leakage when leaking), it is necessary to consider multiple factors. Firstly, pressure detection is set at appropriate positions in each cavity and pipeline system, and all detection values are introduced into the PLC and compared with the preset values stored in the PLC. If there is a significant difference from the set value, the working power is turned off and an alarm is given; Secondly, air control valves are installed between the main components on the pipeline system. When a leakage occurs in one section, the air control valves at both ends of the section can be closed to minimize the leakage. Thirdly, both the air control valve and the solenoid valve controlling the air valve adopt normally closed valves to ensure that the power is cut off immediately and the pipeline system can be isolated in sections.

2)蒸汽濃度監（jiān）測。在（zài）設（shè）備內部高位、中位、低位設置多（duō）處碳氫蒸汽濃度（dù）檢測，並設置合理（lǐ）的爆炸安全下（xià）限（xiàn），達到下限時，設備斷開工作（zuò）電源，並啟（qǐ）動報警。

2) Steam concentration monitoring. Multiple hydrocarbon vapor concentration detections are set at the high, middle, and low positions inside the equipment, and reasonable explosion safety limits are set. When the lower limit is reached, the equipment disconnects the working power supply and initiates an alarm.

3)杜絕明火。一是在設備內部的電機，如旋轉電（diàn）機、真空泵用電機等（děng）均采用防爆電（diàn）機;管係所用（yòng）控製閥（fá）均為氣（qì）動閥，控製氣動閥的電磁閥均安裝在單獨的電控箱內;電（diàn）控箱與設備完全隔離（lí），對電控箱與設備之間的穿線孔全部進行密封;電機、腔體、管係（xì）及機架等均良好接（jiē）地，避免靜電（diàn）產生。

3) Eliminate open flames. One is that the motors inside the equipment, such as rotating motors and vacuum pump motors, are all explosion-proof motors; The control valves used in the pipeline system are all pneumatic valves, and the solenoid valves that control the pneumatic valves are installed in separate electric control boxes; The electric control box is completely isolated from the equipment, and all wiring holes between the electric control box and the equipment are sealed; The motor, cavity, piping, and frame are well grounded to avoid static electricity generation.

4)自動滅火。在設備內（nèi）部（bù）高位、中位（wèi）、低位設置多處煙氣檢（jiǎn）測點，並設置自動二氧化碳滅火器。在檢測（cè）到燃燒時，切斷工作電源，啟（qǐ）動二氧化碳滅火並報警。當滅火完全後，啟動強排裝置（zhì），將碳氫蒸汽及二氧（yǎng）化碳排出設備。

4) Automatic fire extinguishing. Multiple smoke detection points are set up at the high, middle, and low positions inside the equipment, and automatic carbon dioxide fire extinguishers are installed. When combustion is detected, cut off the working power supply, activate carbon dioxide fire extinguishing and alarm. After the fire is completely extinguished, start the forced exhaust device to discharge the hydrocarbon vapor and carbon dioxide from the equipment.