At present, flow meters are used to measure steam flow, and the measurement medium refers to single-phase superheated steam or saturated steam. For steam with frequently varying phase flows, there will certainly be inaccurate measurements. The solution to this problem is to maintain the superheat of steam and minimize the moisture content of steam, such as strengthening the insulation measures of steam pipelines and reducing the pressure loss of steam, so as to improve the accuracy of steam measurement. However, these methods cannot completely solve the problem of inaccurate steam flow measurement, and the fundamental solution to this problem is to develop a flow meter that can measure the two-phase flow medium.
When the working state of steam deviates from the design state, the flow rate will cause errors. It also has an impact on flow measurement, so the measurement of steam flow needs to take compensation measures, and the compensation factors due to the state change of steam are also more complicated. The density of superheated steam is determined by the temperature and pressure parameters of steam, and within different parameters, the expression form of density is also different, and it cannot be expressed by the same general formula, so a unified density calculation formula cannot be obtained, and the temperature and pressure compensation formula can only be derived individually. In the case of large temperature and pressure fluctuations, in addition to temperature and pressure compensation, it is also necessary to consider the compensation of the gas expansion coefficient.
Solution application analysis
Comparison of Saturated Steam Flow Meters
At present, there are more than 60 types of industrial flow meters, mainly including vortex flow meters, differential pressure (orifice plates, average velocity pipes, bends) flow meters, shunt rotor flow meters, Aniu Ba flow meters, float flow meters, etc. There is no flow meter that is applicable to any fluid, any range, any flow state, and any use condition in history. If the flow meter is not chosen properly, the flow rate will definitely not be measured. But flow measurement is a complex technology, and with so many different types of flow meters, choosing the right flow meter for a given application becomes a very technical task that requires careful and in-depth consideration and weighing of many factors related to measurement issues before making a final choice. Therefore, the correct selection of the instrument is the key to the normal use of the instrument, in practical application, too many faults are caused by the unreasonable selection of the instrument, learn more about the working conditions and medium parameters of the field application, choose the appropriate pressure, temperature, protection, explosion-proof grade and material, structure to ensure that the instrument can run in the best state.
Steam metering should consider five main factors when choosing a flow meter: measurement method, performance requirements and instrument specifications, fluid characteristics to be measured, environmental conditions, and economic conditions (purchase cost, installation cost, operating cost, calibration cost, maintenance cost). In our actual work, whether it is used for production central heating in industrial and mining enterprises, the most commonly used are orifice (nozzle) flowmeters and vortex flowmeters, and here we take these two flowmeters as examples to compare and illustrate
The differential pressure flowmeter is a meter that calculates the flow rate by calculating the differential pressure generated by the flow detection device (i.e., the differential pressure generator, referred to as the primary meter) installed in the pipeline, the known fluid conditions and the geometric dimensions of the primary meter and the pipeline, and consists of three parts: differential pressure device, pressure pipe and differential pressure gauge. This differential pressure flowmeter represented by orifice flowmeter has a long history of application, high degree of standardization, and is very widely used, but does not require the standardization of the differential pressure display instrument, as well as the high degree of serialization and generalization, high theoretical accuracy, wide range of applications, strong adaptability, and low initial investment cost.
However, after practical application, it is found that the orifice flow meter also has shortcomings:
(1) Many factors in the application (design parameters are inconsistent with working condition parameters, insufficient length of upstream straight pipe sections, uncentric orifice plate and pipe, contamination of the A side of the orifice plate, wear at sharp angles, etc.) have a great impact on its measurement accuracy, increasing its measurement error and reducing accuracy. In particular, the differential pressure loosener should be checked frequently to ensure the accuracy of the zero point, and the tee valve should be checked frequently to prevent measurement errors caused by blockage.
(2) The installation project is large, troublesome, and demanding, and requires frequent maintenance and dismantling and cleaning.
(3) It is necessary to use a differential pressure transmitter, which increases the workload of maintenance, and the pressure guide pipe needs to be laid outside, and the pressure guide pipe needs to be insulated in winter, and it cannot be installed outdoors.
(4) The flow range ratio is 1∶3~1∶4 and the range is low, which is difficult to measure for small flow rates and the flow range is narrow.
(5) The pressure loss is large, the scale is nonlinear, and the operating cost is high.
Orifice Flow Meter + Differential Pressure Transmitter + Pressure Transmitter + Intelligent Single Compensation Flow Totalizer + Temperature Sensor (not for accumulation, for reference)
V-cone flowmeter + differential pressure transmitter + pressure transmitter + intelligent single-compensation flow totalizer + temperature sensor (not for accumulation, for reference)
The vortex flowmeter is a new type of flowmeter successfully developed based on the principle of Carmen vortex street. The 70s and 80s were a period of rapid development of vortex flow meters, and many types of vortex flow meters with fluid resistance and detection were developed and put on the market in large quantities. In our country's vortex street at the peak of development, it has reached dozens, it should be said that the vortex flowmeter is still a developing product, but because it has the advantages of other flowmeters that cannot be obtained, the proportion of the use of vortex flowmeter has increased significantly, has been widely used in various fields, will dominate in the future flow meter, is an ideal replacement product for orifice flowmeter. It has the following characteristics:
(1) The structure is simple and firm, there are no moving parts in the measuring part, and the long-term operation is very reliable.
(2) The maintenance amount is small, the maintenance is very convenient, and the installation cost is low.
(3) The output pulse signal is directly proportional to the flow rate, no zero drift, high accuracy, and convenient networking with computers.
(4) It has a wide range of applications and is suitable for flow measurement of various gases, vapors and liquids.
(5) The flow measurement range is wide, and the range ratio can reach 1∶10.
(6) Small pressure loss, low operating cost, more energy-saving significance.
(7) Within a certain range of Reynolds, the output signal frequency is not affected by the physical properties and components of the fluid, and the instrument coefficient is only related to the shape and size of the vortex generator.
However, vortex flow meters also have certain limitations:
(1) Vortex flowmeter is a kind of speed flowmeter, the stability of vortex separation is affected by the flow velocity, so it has certain requirements for the straight pipe section, generally the first 10D, the back 5D.
(2) When measuring liquids, the upper limit flow velocity is limited by pressure loss and cavitation, which is generally (0.5~8) m/s.
(3) When measuring gas, the upper flow rate is limited by the change of medium compressibility, the lower limit flow rate is limited by the Reynolds number and sensor sensitivity, and the steam is (8~25) m/s.
(4) The stress vortex flowmeter is more sensitive to vibration, so when installing a flowmeter in a pipeline with large vibration, the pipeline should have certain shock absorption measures.
(5) The stress vortex flowmeter uses piezoelectric crystal as the detection sensor, so it is limited by temperature, generally (-40~+300)°C, and the measurement temperature is not higher than 400°C, otherwise the probe is very easy to be inaccurate due to aging.
(6) Poor anti-electromagnetic interference and radio frequency interference.
(7) When the fluid medium is two-phase flow or pulsating flow, it has an impact on the measurement.
Vortex flow meter (below 250 degrees) + high temperature pressure transmitter + intelligent single compensation flow totalizer + temperature sensor (for reference, not for accumulation)
Boiler drum level measurement system
The following 3D diagram is from the process engineer of Nankong Instrumentation, and the boiler drum level measurement analysis is jointly explained by the field service engineer and the production technology department, hoping to occasionally help you in the measurement of boiler drum level.
Keeping the boiler drum level within the normal range is an important safety indicator for boiler operation. Due to changes in load, combustion conditions and feed water flow, the drum level will change frequently. As we all know, too high or sharp fluctuations in liquid level will cause deterioration of steam quality and water, resulting in salt formation on the heating surface, and in severe cases, it will lead to water shock vibration and blade damage to the steam turbine. If the liquid level is too low, it will cause the pollutant discharge failure, and the drug in the furnace will enter the steam, and even cause the descending pipe to carry steam, affecting the furnace water circulation condition and causing the furnace pipe to burst in a large area. The above-mentioned vicious accidents caused by the measurement and control of the drum level occur from time to time, which seriously affects the safety of thermal power plant operation.
During boiler operation, we monitor and control the drum level through the liquid level measurement system. When the drum level exceeds the normal operating range, the alarm system will send out an alarm signal, and the protection system will immediately take necessary protective measures to ensure the safety of the boiler and turbine. Therefore, the boiler drum level metering system is an extremely important system for the safe operation of the unit.
Schematic diagram of boiler drum level measurement system
Factors affecting the change of drum level
During the operation of the boiler, the liquid level changes frequently. The main reasons for the change of liquid level are the external and internal disturbances of the boiler. When there is external and internal disturbances, the material balance relationship (i.e., the balance relationship between evaporation and feed water) of the evaporation equipment will be destroyed, or the working fluid state will change (when the boiler pressure changes, the specific volume of water and steam will change), resulting in a change in the steam drum level. The drastic change of the steam drum level is not only related to the size of the disturbance amount, but also related to the disturbance speed.
Basic requirements of boiler drum level measurement system According to the importance of boiler drum level measurement and the characteristics of measurement technology, the boiler drum level measurement system should meet at least the following basic requirements:
1. Good accuracy As we all know, the boiler drum level is not a parameter that needs to be accurately controlled compared to the main steam pressure, temperature and other parameters, under normal circumstances, the deviation of the two drum level measurement values within 30mm is acceptable. It is not very difficult to maintain such accuracy under normal conditions. However, due to the complexity of the drum water level measurement object, and the interconnection tube or differential pressure measurement principle adopted for drum water level measurement, the change of drum pressure and measurement reference conditions will cause a very large error far beyond the above requirements. Therefore, for a long time, ensuring the accuracy of drum water level measurement has always been a difficult and key problem in front of us. Guangzhou Nankong Instrument Control Equipment Co., Ltd. solves this difficulty through the principle of differential pressure measurement!
2. Good maintainability The maintenance of the boiler drum level measurement system should be simple, the maintenance workload should be as little as possible, and it should be convenient to carry out the protection linkage test of the online actual water level signal.
Boiler drum level measurement system
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Article source: Nankong Instrument Editor: Marketing Department Popularity: - Publication time: 2013-01-24 17:51
The following 3D diagram is from the process engineer of Nankong Instrumentation, and the boiler drum level measurement analysis is jointly explained by the field service engineer and the production technology department, hoping to occasionally help you in the measurement of boiler drum level.
Keeping the boiler drum level within the normal range is an important safety indicator for boiler operation. Due to changes in load, combustion conditions and feed water flow, the drum level will change frequently. As we all know, too high or sharp fluctuations in liquid level will cause deterioration of steam quality and water, resulting in salt formation on the heating surface, and in severe cases, it will lead to water shock vibration and blade damage to the steam turbine. If the liquid level is too low, it will cause the pollutant discharge failure, and the drug in the furnace will enter the steam, and even cause the descending pipe to carry steam, affecting the furnace water circulation condition and causing the furnace pipe to burst in a large area. The above-mentioned vicious accidents caused by the measurement and control of the drum level occur from time to time, which seriously affects the safety of thermal power plant operation.
During boiler operation, we monitor and control the drum level through the liquid level measurement system. When the drum level exceeds the normal operating range, the alarm system will send out an alarm signal, and the protection system will immediately take necessary protective measures to ensure the safety of the boiler and turbine. Therefore, the boiler drum level metering system is an extremely important system for the safe operation of the unit.
Schematic diagram of boiler drum level measurement system
Factors affecting the change of drum level
During the operation of the boiler, the liquid level changes frequently. The main reasons for the change of liquid level are the external and internal disturbances of the boiler. When there is external and internal disturbances, the material balance relationship (i.e., the balance relationship between evaporation and feed water) of the evaporation equipment will be destroyed, or the working fluid state will change (when the boiler pressure changes, the specific volume of water and steam will change), resulting in a change in the steam drum level. The drastic change of the steam drum level is not only related to the size of the disturbance amount, but also related to the disturbance speed.
Basic requirements of boiler drum level measurement system According to the importance of boiler drum level measurement and the characteristics of measurement technology, the boiler drum level measurement system should meet at least the following basic requirements:
1. Good accuracy As we all know, the boiler drum level is not a parameter that needs to be accurately controlled compared to the main steam pressure, temperature and other parameters, under normal circumstances, the deviation of the two drum level measurement values within 30mm is acceptable. It is not very difficult to maintain such accuracy under normal conditions. However, due to the complexity of the drum water level measurement object, and the interconnection tube or differential pressure measurement principle adopted for drum water level measurement, the change of drum pressure and measurement reference conditions will cause a very large error far beyond the above requirements. Therefore, for a long time, ensuring the accuracy of drum water level measurement has always been a difficult and key problem in front of us. Guangzhou Nankong Instrument Control Equipment Co., Ltd. solves this difficulty through the principle of differential pressure measurement!
2. Good maintainability The maintenance of the boiler drum level measurement system should be simple, the maintenance workload should be as little as possible, and it should be convenient to carry out the protection linkage test of the online actual water level signal.
Heating prepaid control system
As a key encouragement industry for our country's government to save energy and control air pollution, Guangzhou Nankong Instrument Control Equipment Co., Ltd. applies the mature experience in oil pipeline transportation in the petroleum industry to the construction of urban pipeline networks in the heating industry. The wireless data transmission technology in terms of flow, pressure, and safety control of the heating pipe network has won a good reputation from customers.
Part 1: Background and basis of research and development of prepaid system in the heating industry
1. Background of the heating industry
As a key encouragement industry for our country's government to save energy and control air pollution, Guangzhou Nankong Instrument Control Equipment Co., Ltd. applies the mature experience in oil pipeline transportation in the petroleum industry to the construction of urban pipeline networks in the heating industry. The wireless data transmission technology in terms of flow, pressure, and safety control of the heating pipe network has won a good reputation from customers. With the rapid development of cogeneration and central heating in various places, as well as the rising price of coal, a series of metering and charging problems have gradually emerged, in response to the requirements of our customers, the company began to develop a prepayment system in 2002 and after 2-3 years of gradual improvement, it was officially applied to the market in 2005.
2. The main problems solved by the Xisen prepaid system
2.1 The problem of large steam metering loss
As a heating industry, the total from the beginning of the power plant pipeline to the measurement of each sub-household is always very different, and the difference of some heating companies even exceeds 10%, which is very abnormal. As a normal conveying loss, if the pipeline loss should not exceed 1.5% under the premise of large flow (when the flow rate is more than 15 m/s), if it exceeds 1.5%, it indicates that there is an abnormal loss. The large error of pipeline loss mainly occurs in the following aspects:
a. Normal heat loss
When the steam is transported in the pipeline, the temperature will gradually drop, producing a small amount of condensate, this part of the condensate can not be measured by the instrument in the household metering, the amount of condensate is related to the flow rate of steam in the pipeline, the larger the flow rate, the less condensate, the smaller the flow rate, the more condensate is produced, which is a normal loss.
b. Undercounting and omission caused by the characteristics of the meter
At present, in the steam measurement of the heating industry, there are not many flow meters to choose from because of its high temperature, and four flow meters are mainly used for measurement. In addition to the range of 1:10-1:15 for vortex street and V-cone, the flow measurement range ratio of orifice plate and bend pipe is 1:3. Within the measurement range of the flowmeter, the instrument can ensure the accuracy of the measurement, but when the flow rate is lower than the lower limit of the flowmeter, the instrument will miss the meter or even not count; When the flow in the pipeline exceeds the measurement range of the instrument, the fluid will appear jet, and the flow meter cannot be measured, and the data measured by the instrument is far less than the actual flow. The following figure is the relationship between the error and the range of a DN100 vortex flow meter:
When the user's usage fluctuates greatly, then the overall measurement error will increase, and the manifestation is undercounting, missing time, which is naturally the loss of the heating company, which is the most obvious phenomenon in the production enterprise.
c. Caused by malicious steam theft
The price of steam has increased from 60 yuan a ton in 96 to 300 yuan a ton now, and there are more and more cases where users try their best to steal steam, and the means are also varied, and the main means of stealing steam are as follows:
1) Use a big head needle to prick the instrument signal line to cause a short circuit in temperature, pressure or flow signal line to achieve the purpose of stealing steam. When the temperature signal is short-circuited, the temperature shows normal temperature, the vapor density decreases, and the instantaneous flow rate drops several times. When the pressure and flow signals are short-circuited, the measured value is directly displayed as zero, resulting in the flow rate not being counted or the density dropping.
2) Use the flow meter to measure the range characteristics and falsely report the gas consumption, resulting in the wrong selection of the flow meter of the heating company, so that the meter works at the low limit flow rate or high upper limit flow for a long time. Use the error of the instrument to steal steam.
3) Bribe the meter reading or maintenance personnel of the heating company to modify the meter parameters and cause the meter to be undercounted, so as to achieve the purpose of stealing steam.
4) Maliciously cut off the power to the meter, so that the instrument does not work during use, so as to steal steam. The price of steam is high, the usage is large, and once there is a malicious phenomenon of stealing steam, the amount of loss is huge.
2.2 Malicious arrears and capital turnover problems
The unit price of steam is high, and ordinary users spend hundreds of thousands or even millions of dollars every month. On the one hand, coal is shipped on the spot, and on the other hand, the automobile fee cannot be recovered, and once the burden is formed, there will be capital turnover problems. The prepaid system can collect the money in advance, and the funds can be used to organize coal inventory.
3. The basis for the design and development of the prepaid system of Xisen
3.1. The standards and specifications on which the design is based
The software and hardware equipment and technology provided by this program comply with national and local laws and regulations, and organize production and provide technical services in strict accordance with the requirements of the ISO9001 quality assurance system, implement the latest version of international standards, national standards, industry standards and related specifications, and meet environmental protection requirements.
All units of measurement follow the International System of Units (SI system). The following are the units of measurement for commonly used parameters:Part 2 Introduction to the functions of the Xisen anti-theft prepaid control box
Introduction to the functions of the anti-theft prepaid control box
●Wireless remote transmission function:
Data upload: The anti-theft prepaid control box has a built-in GPRS/CDMA wireless transmission DTU module, which can easily upload the user's instantaneous flow, cumulative flow, temperature, pressure, balance, valve opening, door opening and closing status and other information to the computer in the monitoring room. At the same time, it can be combined with the configuration software of the upper computer to analyze the abnormality of temperature, pressure and flow to judge the instrument fault, and at the same time avoid customers from using needle punch signal lines to steal steam, and realize the remote meter reading function.
Instruction transmission: The valve can be closed and opened remotely according to the unexpected situation on site through the monitoring computer, without any distance limitation.
● Unpacking door alarm recording function:
In order to avoid customer collusion in maintenance and meter reading personnel to open the box to modify the instrument coefficient, the control box is not only equipped with double lock facilities, but also has the function of opening the box. Once the box door is opened, the system automatically uploads the unpacking time and status, and records it, and at the same time, you can choose the unboxing alarm and photo function to automatically upload the captured photos or notify the management via short message.
● History curve storage function:
The Xisen anti-theft prepaid controller is full Chinese screen, and can store 365 days of history records of temperature, pressure, and traffic, which can be easily inquired in case of unexpected disputes, and at the same time avoid customers from cheating and stealing steam.
●Report function:
The controller has automatic report function, daily report, monthly report, and annual accumulation, which is convenient for query and reading.
●Recharge record display function:
Record each recharge record to facilitate customers to check and query on site.
●Over-range valve closure function:
According to the measurement range of the on-site instrument, the valve can be set to close the range beyond the range, and when the upper limit range is exceeded, the prepaid controller will automatically close the small valve to control the flow within the flow range. When the measurement range is less than the measuring range or when the flow rate is zero, the valve can be automatically closed according to the set value. To prevent users from maliciously stealing automobiles from over-range.
●Over-range automatic compensation function:
According to the measurement range of the on-site instrument, the loss can be set to automatically compensate for the loss beyond the range range, and when the upper limit and lower limit range are exceeded, the prepaid controller will automatically compensate according to the set requirements; It is used to compensate for losses caused by over-range.
● Overdraft authorization function:
According to the customer's creditworthiness, the overdraft authorization limit can be set arbitrarily to avoid losses caused to customers by closing the valve due to insufficient balance during non-working hours.
● Insufficient balance alarm function:
The charging amount sets the alarm value according to the customer's usage, prompts the user through sound and light alarm in advance, and uploads it to the upper computer at the same time, and informs the user through the phone number of the service staff of the heating company to avoid affecting the normal use of the customer.
●Power off time recording function:
In order to prevent users from stealing through power off, the controller is equipped with a power failure record function, which can record the last 30 power outages and power-on times, which is convenient for query.
● UPS backup power function:
The system is equipped with a backup UPS power supply, which can maintain a continuous power supply time of more than 24 hours. And inform the superior system to pay attention in time.
Overall structure design of the system
As a key encouragement industry for our country's government to save energy and control air pollution, Guangzhou Nankong Instrument Control Equipment Co., Ltd. applies the mature experience in oil pipeline transportation in the petroleum industry to the construction of urban pipeline networks in the heating industry. The wireless data transmission technology in terms of flow, pressure, and safety control of the heating pipe network has won a good reputation from customers.
According to customer requirements, the network can be networked as a whole, and each site is connected to a wireless transmission module to transmit to the data center server. The monitoring system is composed as follows:
1. Hardware part:
Monitoring host: Rack-mounted U-shaped server is selected, including one redundant data server and one WEB server. (Equipped with 22-inch LCD display) Type: Enterprise Category: Rack Structure: 4U
Processor: CPU Type: XeonE7420 CPU Frequency: 2130MHz, with 2 XeonE7420 processors
Maximum number of processors: 4, process process: 45nm, L3 cache: 8MB, CPU core: quad-core (Dunnington)
Motherboard: FSB (bus): 1066MHz, expansion slots: 7 PCI-Express slots (4 x8, 3 x4)
Memory: Memory type: FB-DIMM, memory size: 2GB, maximum memory capacity: 128GB
Storage: Hard disk size: 2*146GB, hard disk type: SAS, maximum hard disk capacity: 1.5TB
Networking: Network controller: 4 embedded BroadcomNetXtreme IITM5708Gigabit5 Ethernet cards,
Interface Type: Standard Interface: Rear: 2 Universal Serial Bus (USB) 2.0 Ports, 9-Pin Serial Port, Video Interface, Gigabit Ethernet Interface for DRAC, ID Button with Blue/Orange LED Indicator, Front: 2 Universal Serial Bus (USB) 2.0 Ports, LCD Panel with System Alert Scrolling Display, 15-Pin Video Interface, System Power On/Off Button, Internal: 1 Universal Serial Bus (USB)
2. System software composition:
When monitoring the screen and data, the customer only needs to enter the account number and password specified by the user from the website to log in. Customers can control their monitoring data anytime, anywhere, as long as they have access to the Internet.
The main functions are:
●24-hour online operation, real-time collection of temperature, pressure, flow rate and other operating parameters of each user sub-station, real-time monitoring of the operation of each collection meter, and the failure of the on-site collection and metering instrument can also be found in a short period of time, and the failure time is recorded for the record to avoid the loss of measurement;
●Carry out operation analysis of the entire pipeline network data, with powerful statistical and database query functions, which can query the steam consumption of any user in any time period; Analyze the pipeline damage in real time and effectively;
●Alarm the user side mains power outage and abnormal collection parameters, and record it for future reference;
● Generate settlement bills (daily, monthly and annual statements) as needed, and can print them out directly;
●Chart curve function, which can intuitively reflect the steam consumption of each user;
● Network design, support remote access function;
●The combination of real-time database and relational database ensures data stability and security.
The powerful software functions combined with high-performance, low-bit error rate data transmission communication equipment and UPS uninterruptible power supply design ensure the stability and reliability of the entire system performance.
Sewage metering system
1. Overview
In today's era, with the improvement of production level, the scale of modern production continues to expand, the fields involved continue to increase, and the types and quantities of resources consumed are rapidly increasing, thus bringing serious environmental pollution problems around the world. With our country attaching great importance to environmental protection issues and accelerating the pace of environmental governance and protection, in order to more effectively promote urban planning and pollution control, it is urgent to comprehensively manage and control sewage discharge, one of the "three wastes" of industry. Therefore, accurate measurement and approval of sewage flow has become a very necessary basic work. At present, many treatment plants have researched and developed slurry integrated sludge treatment system with plate and frame filter press as the main body, changing the traditional belt filter pressure dehydrator and centrifugal dehydrator dewatering can only reach the level of sludge moisture content of about 80%; the traditional way of separating sewage treatment and sludge treatment has been ended; It has driven the development of the downstream industry of sludge treatment; It has laid the foundation for the development of circular economy, energy conservation and emission reduction, and the realization of sludge reduction, harmlessness and resource treatment. This article focuses on Xilin Automationwww.sisen.com.cnThe application of FLDC series electromagnetic flowmeter, BST6600-LT series flanged pressure transmitter, XSFT series flow totalizer, XSPI regulator, AD3800 series ultrasonic level gauge and radar level meter in the "slurry and water integration" sludge treatment technology.
2. Installation diagram of the metering system of the "slurry and water integration" project of the sewage plant
In this sewage metering system, the FLDC series sewage flow meter (electromagnetic flowmeter) produced by Nankong Instrument is used to measure the inlet flow of the sewage tank main pipe, the inlet flow rate of the sewage filter and the outlet flow rate of the liquid filter (two electromagnetic flowmeters for each filtrate machine); The XSFT universal flow totalizer is installed in the control room and displays the instantaneous and cumulative flow rates of all flow meters. BST6600-LT series single-flange pressure transmitter is used to measure the pressure of the pipeline (range: 0-2.5MPa and 0-4MPa), followed by the XSPI intelligent regulator, to control the output of 4-20mA to adjust the frequency converter, so as to control the pressure of the pipeline.
In addition, AD3800 series ultrasonic level gauge is used for liquid level measurement of dosing tank and mixing tank, with a range of 6 meters and 8 meters), this link due to the existence of the stirring rod in the tank, so there is an error in measuring the liquid level with AD3800 series ultrasonic level gauge, our company suggests that the treatment plant with economic ability can consider using the AD113 series radar level gauge produced by Nankong Instrument or the BST6800-LT series single-flange level transmitter to solve this problem.
3. On-site installation drawing
Sewage treatment tank
Sewage inlet pipe DN200 sewage flow meter
(The installation here is produced by Nankong Instrument.)FLDC series sewage flow meter, the lining is made of Teflon to measure the flow rate of the main pipe inlet)
Plate and frame filter press filtrate drainage pipe DN150 sewage flow meter (electromagnetic flow meter)
(The FLDC series sewage flow meter produced by Nankong Instrument is installed here, and the lining is made of polytetrafluoroethylene, which is mainly used to measure the flow rate of the inlet and outlet of the filter press)
