亚洲 日本 欧美 中文幕,午夜成人理论无码电影在线播放,久久aⅴ免费观看,五月天亚洲图片婷婷

Cancel
022-68673666
NewsA group high-tech enterprise integrating R & D, production and sales

Analysis of Common Problems in Vacuum Dryer

Release time:2016-12-27 Views:2343

Common problem one:
What is the difference between the meter reading of the vacuum drying box and the glass thermometer reading in the vacuum chamber?
Generally, the electric heating vacuum drying box adopts the method of heating the wall of the vacuum chamber first, and then heating the wall from the wall to the workpiece. In this way, the temperature sensor of the temperature control instrument can be arranged on the outside wall of the vacuum. The sensor can accept convection, conduction, and radiant heat simultaneously. The glass rod thermometer in the vacuum chamber can only accept radiant heat, and because the blackness of the glass rod cannot reach 1, a considerable part of the radiant heat is refracted, so the temperature value reflected by the glass rod thermometer must be lower than the temperature reading of the meter. . Generally speaking, it is normal for the temperature reading of the meter and the reading of the glass rod thermometer to be within 30 ° C at 200 ° C. If the temperature sensor of the temperature control instrument is arranged in the vacuum chamber, the difference between the temperature value of the glass rod thermometer and the temperature reading of the instrument can be appropriately reduced, but it is impossible to eliminate, and the sealing reliability of the vacuum chamber adds a potentially unreliable link . If you do not want to see this difference from a practical point of view, you can use the display correction function unique to the temperature control instrument.
FAQ 2: Why is the vacuum drying box vacuumed and then heated up?
1) If the procedure of heating up and then vacuuming is followed, when the heated air is pumped out by the vacuum pump, the heat will be carried to the vacuum pump, which will cause the temperature of the vacuum pump to rise too high, which may reduce the efficiency of the vacuum pump.
2) The heated gas is directed to the vacuum pressure gauge, and the vacuum pressure gauge will generate a temperature rise. If the temperature rise exceeds the operating temperature range specified by the vacuum pressure gauge, it may cause the display error of the vacuum pressure gauge. The correct method of use should be vacuumed first and then heated up. After reaching the rated temperature, if you find that the degree of vacuum has decreased, you should pump it appropriately. This is beneficial for extending the life of the equipment.
3) The workpiece is placed in a vacuum box to evacuate to remove the gas components that can be removed from the material of the workpiece. If the workpiece is heated first, the gas will expand when heated. Due to the tightness of the vacuum box, the huge pressure generated by the expanding gas may cause the tempered glass of the observation window to burst. This is a potential danger. You can avoid this danger by following the procedure of vacuuming and heating first.
Common problem three
Reasons why the vacuum drying box does not have a temperature uniformity parameter General electric heating (blast) drying boxes are equipped with temperature uniformity parameters: the natural convection drying box is the upper limit of the operating temperature multiplied by 3%, and the forced convection drying box is the work Multiply the upper temperature limit by 2.5%. But the electric heating vacuum drying box does not set the temperature uniformity parameter. Why is this? The possibility that the temperature of the working chamber can be made uniform in the vacuum drying box by the movement of gas molecules is almost gone.
Therefore, conceptually we can no longer define the uniformity of temperature specified by the ordinary electric heating (blast) drying box to the vacuum drying box. It is also meaningless to set this index in a vacuum state. The amount of heat radiation is inversely proportional to the square of the distance. For the same object, the radiant heat received at a distance of 20 cm from the heating wall is only 1/4 of that at a distance of 10 cm from the heating wall. big difference. This phenomenon is similar to the fact that when the sun is exposed in winter, the side that is exposed to the sun is very warm, and the side that is not exposed to the sun is relatively cold. Because the structure of the vacuum drying box is difficult to make the radiant heat of each point in the three-dimensional space of the studio uniform, and it lacks an authoritative evaluation method. This may be that the temperature uniformity parameter is not set in the standard of the electric heating vacuum drying box. s reason.

Previous:Some common faults and troubleshooting methods of constant temperature and humidity testNext:Some related issues of chromatography
国产又黄又爽胸又大免费视频| 男女下面一进一出免费视频网站| 国产精品美女久久久网av| 2020最新无码福利视频| 日产亚洲一卡2卡3卡4卡网站| 99久久精品国产一区二区| 亚洲欧洲无码专区AV| 国产日韩久久免费影院| 欧美亚洲另类 丝袜综合网| 中文字幕无码日韩欧毛| 国产乱码一区二区三区| 亚洲欧美日韩国产精品专区| 国产片免费福利片永久| 亚洲精品无播放器在线播放| 国产无吗一区二区三区在线欢| 日韩精品无码一区二区三区av| 亚洲中文在线精品国产| 白嫩少妇激情无码| 手机看片久久高清国产日韩| 亚洲国产精品国语在线| 国产高清自产拍AV在线| 一区二三区四区精华液| 久久九九有精品国产尤物| 精品精品国产高清A毛片牛牛| 国产精品青青在线观看爽香蕉| 我把寡妇日出水好爽| 亚洲欧洲国产精品香蕉网| 亚洲熟妇久久国内精品| 亚洲国产精品一区二区久久hs| 99久久亚洲综合精品成人网| 国产丝袜视频一区二区三区| 蜜芽忘忧草老狼二区欢迎您| 亚洲天天做日日做天天谢日日欢| 国内精品日本和韩国免费不卡| 最近最好看的2018中文字幕电视剧| 两个奶头被吃高潮视频| 色婷婷欧美在线播放内射| 2020最新无码福利视频| 欧美男男激情VIDEOS高清| 欧美性大战久久久久XXX| 性色AV一区二区三区咪爱四虎|