Introduction To Industry Scenarios
Petrochemical industry is characterized by high temperature, high pressure, flammability and explosiveness, strong corrosion, multiphase mixing, high vibration, and strong electromagnetic interference. The process covers crude oil extraction/gathering and transportation, refining (atmospheric and vacuum distillation/catalytic cracking/hydrogenation), tank area (crude oil/finished oil/chemical raw materials), oil and gas separation, sewage treatment, flare venting, heat exchange network, etc.
Typical measuring points:
Atmospheric and vacuum distillation tower/fractionation tower: bottom/middle/top liquid level, feed/reflux pressure, negative pressure inside the tower
Hydrogenation/reaction kettle: high temperature and high pressure liquid level, reaction pressure, catalyst pressure difference
Tank area: Crude oil/refined oil/asphalt/acid-base tank level, pressure, temperature, and boundary position
Oil and gas processing: separator liquid level, oil and gas interface pressure, pipeline pressure/pressure difference
Wastewater treatment: Oil/sulfur containing wastewater tank level, acid-base neutralization tank level/pressure
Explosion proof area: oil pump room, tank area, hydrogenation unit (Ex d/Ex ia explosion-proof)
Adapt to Core Products
QDY30A/QDY60 series immersion type liquid level transmitter (high temperature 150 ℃, anti-corrosion 316L/Hastelloy, explosion-proof Ex d II CT6)
QDW90A-3051 single/double flange liquid level transmitter (high temperature 200 ℃, high pressure 10MPa, viscous/easy to crystallize medium, closed container)
QDKG intelligent pressure switch/pressure transmitter (0.075 level, high temperature of 200 ℃, negative/micro pressure, explosion-proof/intrinsic safety, anti vibration)
GLG series signal isolator/RS485 isolation converter (2500V isolation, common mode rejection, explosion-proof area signal safe transmission)
S803/SS803 Intelligent Digital Display Instrument (Local Display, Alarm Interlocking, Explosion proof Shell, Modbus Communication)
Product Function
QDY30/QDY60+QDW90A-3051 liquid level class
Tower/reactor liquid level: 0.2 level accuracy, real-time monitoring of fractionation tower and hydrogenation kettle liquid levels, outputting 4-20mA/RS485 to DCS, participating in reflux control, feed adjustment, high and low liquid level interlocking, emergency shutdown, ensuring fractionation purity and reaction stability.
Tank area liquid level/boundary: Single flange compatible with viscous/easily crystallized media (crude oil, asphalt, residual oil), high temperature resistance of 150 ℃, anti-corrosion PTFE/Hastelloy alloy, anti clogging, anti scaling, long-term stable measurement, supports inventory counting and trade handover.
Sealed container/oil-gas separator: Double flange measurement of differential pressure eliminates the influence of gas phase pressure fluctuations inside the tank, accurately monitors the oil-gas/oil-water interface, and improves separation efficiency.
Oily wastewater/acid-base tank: PVDF anti-corrosion probe, IP68 protection, suitable for strongly corrosive and suspended media, long-term immersion stable measurement.
QDKG intelligent pressure switch/transmitter
Process pipeline/equipment pressure: 0.075 level high precision, temperature resistance of 200 ℃, real-time monitoring of crude oil/finished oil/steam/hydrogen pressure, participation in load regulation, safety valve calibration, overpressure/underpressure interlocking, pump/compressor start stop control.
Hydrogenation/High Pressure Reactor: High pressure type (0-10MPa), explosion-proof certification, monitoring reaction pressure and catalyst bed pressure difference to prevent overpressure explosion and catalyst failure.
Tank area/pipeline pressure: Micro pressure/negative pressure monitoring of tank top breathing pressure and pipeline pressure difference to prevent tank collapse/bulging and leak detection.
Explosion proof area (tank area/oil pump room/hydrogenation): Ex d II CT6 explosion-proof/intrinsic safety certification, suitable for IIC level explosion-proof areas, eliminating the risk of spark ignition.
GLG signal isolator/RS485 isolator
Strong electromagnetic interference environment (compressor/frequency converter/large motor): 2500Vrms electrical isolation, cutting off ground loop, suppressing common mode interference, preventing DCS signal drift, jumping, and misoperation.
Long distance signal transmission (with a distance of hundreds of meters between tank areas/devices): RS485+Modbus, anti attenuation, anti packet loss, time synchronization, ensuring stable data upload to the dispatch center.
Explosion proof zone → safety zone signal isolation: Intrinsic safety isolation, limiting energy and meeting the safety requirements of explosion-proof circuits.
S803/SS803 digital display instrument
On site visualization: explosion-proof shell, high brightness LED, strong light resistance, vibration resistance, temperature resistance of 85 ℃, suitable for outdoor/explosion-proof area on-site display, convenient for inspection.
Alarm/interlock output: upper and lower limit alarm, relay contact output, driving sound and light alarm, linking emergency shut-off valve/vent valve, shortening response time.
Data accumulation/communication: Supports Modbus, uploads DCS/SCADA, enables data traceability, energy consumption statistics, and fault analysis.
Addressing Industry Issues
Extremely high safety risk
High temperature and pressure can easily cause explosions, leaks, and fires; Flammable and explosive media ignite upon contact with sparks; Loss of control of liquid level/pressure leads to damage to the tower, dry kettle, and equipment.
The measuring conditions are extremely complex
High temperature (150 – 200 ℃), high pressure (4 – 10MPa), strong corrosion (acid-base/organic solvent), viscous/crystallizable/foam medium, large drift, easy plugging, short life and poor accuracy of ordinary instruments.
Serious signal interference
Large compressors, frequency converters, and motors generate strong electromagnetic interference, causing signal jumps, drifts, and false alarms, which affect process control and interlock reliability.
High maintenance costs and significant downtime losses
Frequent instrument failures require downtime for maintenance, manual cleaning/calibration, and frequent replacement; Unplanned downtime results in losses of millions per day.
High energy consumption and unstable product quality
Inaccurate control of liquid level/pressure leads to fluctuations in fractionation purity, low reaction conversion rate, high energy consumption, and waste of raw materials.
Direct Customer Benefits
Safety benefits (core)
Explosion proof instruments and isolators eliminate the risk of sparks in explosion-proof areas, meet the GB 3836/GB 50160 explosion-proof specifications, and reduce the safety accident rate by ≥ 90%.
Interlocking of high and low liquid levels/overpressure to prevent tower flushing, dry reactor, and explosion accidents, reducing unplanned shutdowns by ≥ 95%.
Tank/pipeline pressure monitoring to prevent tank collapse/bulging, leakage, and reduce environmental pollution and safety hazards.
Precision and stability benefits
High precision of 0.2-0.075 level, liquid level/pressure measurement error ≤ ± 0.1% FS, fractionation purity increased to 99.9%, and reaction conversion rate increased by 2% -5%.
Isolators suppress interference, signal drift is ≤ ± 0.05% FS, jump elimination, and DCS misoperation reduction is ≥ 98%.
High temperature/anti-corrosion/explosion-proof design extends instrument life by 2-3 times and reduces failure rate by ≥ 80%.
Cost benefit (quantitative)
Raw material/energy consumption reduction: precise control, refining equipment energy consumption reduced by 3% -5%, raw material loss reduced by ≥ 2%, annual cost savings of ≥ 10 million yuan.
Reduced maintenance costs: extended lifespan+decreased failure rate, reduced annual maintenance costs by ≥ 70%, and reduced labor/spare parts expenses by ≥ 800000 yuan.
Reduced downtime losses: Unplanned downtime is reduced by 95%, avoiding single downtime losses of ≥ 5 million yuan.
Management and compliance benefits
Accurate and traceable data, meeting SH/T standards and environmental VOCs emission requirements in the petrochemical industry, and avoiding fines.
On site and remote display, inspection efficiency has been improved by ≥ 60%, and labor costs have been reduced.
Intelligent interlocking+alarm, response time ≤ 1 second, accident handling efficiency improved by ≥ 90%.
