Insulation and antifreeze measures for instruments and meters in winter

Anti-freezing treatments for meters and meter measurement pipelines usually include: model selection, heat preservation and heat tracing, maintenance (point inspection, sewage discharge), etc. In winter, when the measured medium is transmitted to the transmitter through the measuring pipeline, freezing, solidification, precipitation and crystallization will often occur when the ambient temperature is too low. The ambient temperature is too low and exceeds the normal operating temperature of the instrument used. Anti-freezing treatment for meters and meter measurement pipelines usually includes: model selection, heat preservation and heat tracing, maintenance (point inspection, sewage discharge), etc. In winter, when the measured medium is transmitted to the transmitter through the measuring pipeline, freezing, solidification, precipitation and crystallization will often occur when the ambient temperature is too low. The ambient temperature is too low and exceeds the normal operating temperature of the instrument used. The interval directly affects the accuracy of the meter's measurement display. For this reason, the meter and meter measuring pipeline must be anti-freeze treatment. The objects that need heat tracing and insulation are mainly transmitters installed in the incubator of the meter, external float type liquid level transmitters or other forms of open-air installation liquid level. Transmission unit, pressure, differential pressure, flow and other instrument detection pipelines and measurement pipelines. Avoid such accidents through selection or other means. The measures taken usually include: model selection, heat preservation and heat tracing, maintenance (point inspection, sewage discharge), etc. 1. Model selection measures: Choose an instrument with a thermal insulation device. According to the type and purpose of the instrument and the geographical location to be installed, put forward the insulation and antifreeze requirements of the instrument, and then submit it to the manufacturer for processing. In some places in the north, the temperature difference between day and night is too large, and the temperature can reach more than -20 degrees at night. However, choosing heat preservation and heat tracing, maintenance (point inspection, sewage discharge) and other methods are the best solutions for antifreeze. 2. Heat preservation measures Use heat preservation materials for heat preservation, that is, use heat preservation materials to wrap the parts of the meter that are easy to freeze or are afraid of freezing. When winter comes, check and discharge sewage frequently to prevent damage to the packaging insulation materials. 3. Heat tracing measures 1. Steam heat tracing measures, that is, use pipe steam heating for heat preservation. Check whether the steam insulation pipeline is unblocked or blocked before heat preservation and steam delivery in winter. It is best to keep the steam open 24 hours a day, not too hot, and sometimes adjust the amount of heat preservation steam according to the weather and temperature changes to prevent the temperature from being too high to vaporize the condensate in the pressure pipe of the transmitter and affect the operation of the transmitter or due to the temperature. If it is too low, the condensate in the pressure pipe of the transmitter will be frozen and the transmitter will work smoothly. 2. Measures for the insulation protection box a. The electric heating pipe heat tracing insulation box is composed of three parts: a box body, a heater, and an instrument bracket. Its structure is the same as that of the protection box, except that the box is equipped with an electrical heating device. The structure is as shown in the figure. The electric heating device is composed of an electric heating tube and a temperature controller. There are sockets on the side of the box. When the power is turned on, the inside of the box is heated to the required temperature, and then the temperature controller is turned on to continue heating. . Through repeated work, the temperature in the box can be kept within a certain range. The main parameters of the constant temperature heater: ⑴, rated voltage 200V.50Hz ⑵, rated power 300～500W ⑶, control temperature can be customized by the user ⑷, constant temperature heater can also be made into explosion-proof type ⑸, there are three types of electric heating tube materials: namely copper Pipe, carbon steel pipe, stainless steel pipe. b. Steam pipe heat tracing incubator. The heat tracing pipe is made of metal pipes in S-shaped structure. The upper and lower parts of the box are welded with welded through-plate joints and heat tracing pipes. The heat tracing pipes are installed in the box for top in and bottom out. Circulation in the lumen for heating purposes. Heat tracing pipe materials are generally divided into two types, namely copper pipes and seamless steel pipes (carbon steel). c. Add another layer of insulation cotton to the key instrument box, and add glue to seal the door of the insulation box and the inlet and outlet pipelines to achieve better insulation and antifreeze effect of the instrument system. 3. Electric heating belt measures Electric heat tracing insulation technology is a new type of heating technology that directly converts electrical energy into thermal energy. Install thermal insulation cables, wind the heating cable around the instrument, or stick it inside the instrument cabinet (but pay attention to the length of the heating cable used, and it should be economical and moderate). Suitable for heating, antifreeze and heat preservation of pipelines, valves and pumps, or for maintaining the process temperature of instrument pipelines. The heating per unit length is constant, and the output power is not changed by the change of the ambient temperature. The length and power of the use are In proportion, it can be spliced u200bu200barbitrarily during installation, but there must be a heating section (that is, at least 2.5m). The outer braid has the function of heat transfer and heat dissipation, and can be used as an anti-static safety ground. It is mainly used for antifreeze and heat preservation of various pipes and instruments, and the maximum temperature is 150℃. Note: Heat tracing and heat preservation of liquid pipelines that require strict temperature control (a temperature controller must be used). There is also a product on the market, which is a soft-packed electric heat tracing protective cover, which is specially used for heat tracing and explosion-proof of instruments in a relatively small space. It is mainly installed in the pressure pipe and valve of the instrument. 4. Maintenance measures 1. Installation measures Reasonably choose the installation location: a dry place with no rain or snow. 2. Checking measures When conditions permit, a dedicated person shall conduct technical confirmation and technical disposal on whether the insulation material is damaged or the steam pipeline is blocked on a daily basis. 3. Alarm measures If possible, a small sound and light alarm device for steam leakage or power failure can be installed to facilitate the discovery and timely rectification of hidden dangers of heat preservation and antifreeze measures. 4. Inspection measures The person in charge of regional instrument maintenance shall conduct regular inspections according to the scheduled inspection route. During the inspection, check whether the insulation pipeline valve is normal, whether the incubator is normal, whether the drainage device is normal, whether the insulation material packaging is intact, whether the electric heating power supply components are normal, etc. Carry out key inspections of the easy-to-freeze device meters and make inspection records, conduct dry, complete and clean maintenance of the meters and their insulation and anti-freezing measures, and solve the problem of heat preservation and heat tracing on the spot in time.