Application of elbow flowmeter in metallurgical industry

The elbow flowmeter is an old and young flow measurement device. In order to make more colleagues care about and understand its practicality, so that this energy-saving and consumption-reducing flow measurement device can be better promoted and applied, we are very willing to do some specific work. However, our knowledge is very limited. It is impossible to fully explain the practicality of the elbow flowmeter in all walks of life. We can only write some experience based on our superficial understanding of the alkali industry and the characteristics of the elbow flowmeter to play a role in throwing out bricks and attracting jade. With different elbow materials and appropriate geometric dimensions, the elbow flowmeter can adapt to the flow measurement of most process media and process conditions in the alkali system (the vast majority of process media mentioned here do not include the following special process media such as lime emulsion, alkali solution, etc. These two media are easy to deposit and scale, which will block the pressure pipe and are not suitable for flow measurement with elbow flowmeters. It is better to use electromagnetic flowmeters). As for refined brine, ammonia brine, etc., elbow flowmeters can be used for flow measurement. Therefore, it can be said that the scope of application of elbow flowmeters is very broad. Devices and media suitable for flow measurement with elbow flowmeters.

1. Kiln gas and furnace gas system

In the alkali system, steam is generally divided into medium-pressure steam and low-pressure steam, both of which are almost superheated steam. The steam at the boiler outlet, steam turbine, steam turbine compressor, steam turbine vacuum machine inlet, light ash calcining furnace inlet, and heavy ash calcining furnace inlet with slightly lower temperature and pressure all belong to the category of medium-pressure steam, which is characterized by relatively high temperature and pressure. A large amount of low-pressure steam is mainly used in mother liquid distillation tower and light liquid distillation tower. Almost all of these steam flows are orifice flowmeters, and their main disadvantages are large resistance loss, easy leakage, and very difficult maintenance.

2. Measurement of steam turbine compressor air volume

The steam turbine compressor air volume is a very important process parameter. Due to the large pipeline, it is difficult to install an orifice flowmeter. At the same time, excessive resistance loss will greatly increase the load of the compressor. Therefore, the monitoring of this parameter is abandoned in the design, which is very unfavorable for the safe operation of the steam turbine compressor. The elbow flowmeter is particularly suitable for use in situations with large pipe diameters, large flows, and low pressures. It will not increase the load on the steam turbine compressor. If, in actual construction, our company's on-site transformation technology is used to transform the existing standard elbow into an elbow sensor, the construction difficulty is very small, and this transformation task can be completed very conveniently.

3. Flow detection of the lower section gas, middle section gas, and cleaning gas of the carbonization tower

Several or more than a dozen carbonization towers are operated in parallel, and it is very important to reasonably allocate limited gas resources. Therefore, the flow detection of the lower section gas, middle section gas, and cleaning gas of the carbonization tower is indispensable. Replacing numerous orifice flowmeters with elbow flowmeters will inevitably greatly reduce the load of the steam turbine compressor, which is definitely beneficial to energy saving and consumption reduction.

4. Detection of furnace gas flow at the outlet of the light ash calcining furnace

The load of the light ash calcining furnace can be achieved by controlling the amount of heavy alkali entering the furnace. However, for heavy alkali with relatively high water content, accurate measurement of solid materials is very difficult. Therefore, steam consumption is generally used to indirectly infer the actual load level of the calcining furnace. If the outlet gas flow of each light ash calcining furnace can be measured at the same time, it will be very helpful for accurately estimating the actual load level of the calcining furnace. Since the cooling and purification system of the furnace gas is not one-to-one corresponding to the light ash calcining furnace, there is almost no type of elbow flowmeter that can effectively detect its flow before the furnace gas is cooled and purified. Therefore, the light ash calcining furnace does not have a single furnace gas flowmeter, which is undoubtedly a defect for optimizing the operation of the calcining furnace. The elbow flowmeter can better solve this problem. The high-temperature furnace gas carrying a large amount of soda ash dust will not cause too much trouble for the accurate measurement of the elbow flowmeter. It can easily measure the actual furnace gas volume of a single light ash calcining furnace without increasing the load of the compressor. This is an ideal solution.

Steam system

In the alkali system, steam is generally divided into medium-pressure steam and low-pressure steam, both of which are almost superheated steam. Steam at boiler outlet, steam turbine, steam turbine compressor, steam turbine vacuum machine inlet, light ash calcining furnace inlet and heavy ash calcining furnace inlet with slightly lower temperature and pressure all belong to the category of medium-pressure steam, which is characterized by relatively high temperature and pressure. A large amount of low-pressure steam is mainly used in mother liquor distillation tower and light liquid distillation tower. Almost all of these steam flows are orifice flowmeters, and their main disadvantages are large resistance loss, easy leakage, and very difficult maintenance.

For large boilers, the degree of automation is relatively high. In order to improve the thermal efficiency of the boiler, the boiler air supply volume is a must-measure parameter. However, the boiler air supply duct is generally square and vibrates relatively large. Conventional flow measurement devices are difficult to meet the requirements. If a bend flowmeter is used to measure the boiler air supply volume, we can modify the less standard square air supply duct bend to make a non-standard bend sensor, so that this measurement problem can be effectively solved. Of course, the measurement accuracy of the bend sensor made by this modification is limited, but it still retains the advantage of good repeatability. As long as necessary corrections are made, it can meet the measurement requirements for the boiler air supply volume.