Mica shields are also commonly used in steam water applications to prevent etching and the weakening of the glass Magnetic Level Gauge: Mica Sheet use in transparent level gauge: Mica sheet are widely used in visual liquid level to protect the glass surface from the corrosive effects of hot alkaline or acidic solutions. for steam with an operating pressure > 20 bar.The transparent level gauge is particularly recommended for applications where the glass needs to be protected from corrosive fluids and high temperatures. To protect glass surfaces from corrosive action of the process fluid, Transparent Level Gauges can be fitted with Mica shields. The fluid level is indicated as the result of the different transparency of the two media. Transparent level gauges are always fitted with two plate transparent glasses between which the fluid is contained. when the process fluid is high-pressure water steam, since in this case the glass must be protected from the solvent action of the boiler water by using mica shields.when the separation level between two liquids has to be read (interface).Reflex level gauges cannot be used in certain cases as for example: Reflex glass level gauges can be used in most of the fluids and applications. For same reason they will be reflected and turned by 90° towards the observer, to whom the zone will appear silver bright. Since this angle is greater than glass/gas-vapor critical angle, the rays are not refracted, but totally reflected making 90° turn, thus reaching the nearest glass/gas-vapor interface again with angle of 45°. As for the liquid zone, the light rays reach the glass/gas-vapor interface with an angle around 45°. This zone appears silver bright to the observer. In fact the zone will appear dark, nearly black, to the observer. Therefore the rays incident within the critical angle are refracted within the liquid and, since the internal walls of the gauge chamber are not reflecting, the rays cannot be seen from the outside. The critical angle glass/liquid is always superior to 45°. These rays reach the glass/liquid interface with an inclination of approx. This zone appears dark when the gauge is in operation the light ray’s incident on the external face of the glass are quite perpendicular to said face and, therefore, not deviated by the glass. The day light is enough for seeing the level. The reflex level gauges do not need a specific illumination. The liquid level is well-known by different brightness of the glass in the liquid and in the gas/vapor zone. When in operation, the chamber is filled with liquid in the lower part and gases or vapors in the upper part. Reflex glass level gauges use glasses having the face fitted towards the chamber shaped to have prismatic grooves with section angle of 90°. Reflex glass level gauges working principle is based on the light refraction and reflection laws. Magnetic type level gauge Reflex level gauge:.There are commonly 3 types of level gauges used: The weight of the material Types of Level Gauge:.The position (height) of the liquid surface.Level devices operate under three main different principles: On each window a special high resistance glass is used with sealing joint and metal cover plate hold by bolts and nuts. Level gauge consists of a metal body, machined to have an internal chamber and one or more front windows. Level gauge is a direct method for measuring the level. Depending on the type of application used, the type of level gauge should be selected. Level gauge is a device which is used to show the level of fluids in fields.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |