报道在冬天，尤其北方的冬天，随着气温的降低，当被测介质通过测量管线传送到变送器时，常出现环境温度过低发生冻结、凝固、析出结晶等现象，因环境温度过低而超出所使用仪表的正常工作温度区间，直接影响到仪器仪表测量显示的准确性。 Two-needle pressure gauges are reported in winter, especially in winter in the north. As the temperature decreases, when the measured medium is transmitted to the transmitter through the measurement pipeline, freezing, solidification, and precipitation of crystals often occur when the ambient temperature is too low. The ambient temperature is too low and exceeds the normal working temperature range of the instrument used, which directly affects the accuracy of the instrument display. For pressure, flow rate, liquid level, temperature and other instrument points, the measurement medium is mostly liquid. Affected by low temperature, it is more likely to cause measurement errors, and serious cases may cause poisoning, fire, explosion and other safety accidents. Therefore, it is especially important to protect the instrument from cold and frost every winter. And some large instrument and meter users are ready to respond in advance. For example, power plants, petroleum, chemical, water plants, etc. have developed a system for the instrument's cold protection and antifreeze work, and prevent and freeze the instrument. And so on. Here, Jiangsu Jinhu Dongxiang Instrument Co., Ltd. combines years of production practice experience, and discusses with you how the meter user can protect the instrument from cold and frost in winter.
要做好仪器仪表的防冻，我们认为产品的选型是一个关键，在前期安装仪表时，仪表用户就应该考虑仪表所在的工况条件，选带保温装置型仪表。 In order to prevent the freeze of the instrument, the dual-needle pressure gauge is of key importance. When installing the instrument in the early stage, the user of the instrument should consider the working conditions of the instrument and choose an instrument with a thermal insulation device. According to the category and application of the instrument and the geographic location where it is to be installed, the insulation and antifreeze requirements of the instrument are proposed, and then submitted to the manufacturer for processing. Regarding the selection of Hengtai Fengke, the following suggestions are made: 1. The signal remote transmission instrument and display meter should consider the environmental temperature resistance requirements, and the isolation liquid should be considered the environmental temperature resistance requirements. 2. Mass flowmeters, metal rotor flowmeters, electric target flowmeters, volumetric flowmeters, etc. generally do not require separate heat tracing. 3. First of all, the practicality and economics of the meter are generally considered when selecting the type. Practicality refers to convenient maintenance and accurate measurement. Economics is cheap. The two must be combined with each other. Mass flow meters, metal rotors, and electric targets cannot be selected for convenience and maintenance-free use. Therefore, I think that the correct selection is only a measure to prevent freezing and condensation. When installing the meter, fully consider the anti-freezing and anti-condensation of the meter. For example, the pressure guiding pipe should be as short as possible, and the pollution inspection and drainage should be carried out. 4. In some places in the north, the temperature difference between day and night is too large, and it can reach -20 degrees at night. If the solution is selected, the cost performance is quite uneconomical. The choice of heat preservation and heat tracing, maintenance (point inspection, sewage) is the best solution to prevent frost.
讲述仪器仪表防冻方法的保温措施： The double needle pressure gauge describes the insulation measures of the instrument antifreeze method:
1. Insulate with insulation material, that is, use the insulation material to wrap the parts that are easy to freeze or are afraid of freezing. When winter comes, check and drain frequently to prevent the packaging's insulation material from being damaged. 2. Heat tracing measures Steam tracing measures: That is, using pipe steam heating to keep heat. Check whether the steam insulation pipeline is unblocked or blocked before supplying heat and steam in winter. It is best that the steam is available for 24 hours. Don't be too hot, and sometimes adjust the heat supply steam according to the change of weather temperature to prevent the temperature from being too high, which will cause the condensate in the transmitter pressure tube to vaporize and affect the transmitter's operation or due to temperature. Too low makes the condensate freezing in the transmitter pressure tube affect the smooth operation of the transmitter. 3. Insulation protection box measures: a. Electric heating tube heat tracing insulation box, which consists of three parts: box body, heater, and instrument bracket. Its structure is the same as that of the protection box, except that the box is equipped with electrical heating devices. The heating device is composed of an electric heating tube and a temperature controller. The side of the box is equipped with a socket. When the box is heated to the required temperature after the power is turned on, the temperature controller is connected to the power to continue heating. Through repeated work, the temperature inside the box can be kept within a certain range. Main parameters of its 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 pipe materials: copper pipe, carbon Steel pipe, stainless steel pipe.
b. Steam pipe heat tracing insulation box. The heat tracing pipe is made of S-shaped structure with metal pipes. The upper and lower sides of the box are welded by welding through plate joints and heat tracing pipes. The heat tracing pipe is installed in the box to enter and exit. Circulation in the lumen to achieve heating purposes. The materials of heat tracing pipes 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 rubber seals to the door of the insulation box and the inlet and outlet pipelines to achieve better insulation and freeze protection of the instrumentation system.