Application of Explosion-Proof AGVs in Chemical and Pharmaceutical Workshops: A Comprehensive Analysis from Motor Selection to Certification
In the chemical and pharmaceutical industry, the presence of ethanol vapor, suspended cephalosporin dust, and high-temperature, high-pressure reaction vessels in workshops creates potential "invisible bombs." Traditional manual handling or ordinary AGV equipment, unable to isolate static electricity, sparks, or high temperatures, can trigger explosion accidents at any time. A pharmaceutical company once experienced a workshop shutdown for three months due to an explosion caused by static sparks igniting ethanol vapor during manual handling, resulting in direct economic losses exceeding ten million yuan. Such cases are not isolated but represent common pain points in the industry.
The emergence of explosion-proof AGVs offers a systematic solution to this challenge. By integrating technologies such as explosion-proof motors, explosion-proof enclosures, and static electricity dissipation, they nip explosion risks in the bud. However, from motor selection to whole-machine certification, the implementation of explosion-proof AGVs involves complex technical decisions and compliance processes. This article provides an in-depth analysis of this entire process to help companies avoid selection pitfalls and achieve a dual improvement in safety and efficiency.
The explosion risks in chemical and pharmaceutical workshops are "dual"—coexisting gas explosions (e.g., ethanol and acetone vapors) and dust explosions (e.g., cephalosporin and starch dust). For example, in an API synthesis workshop, Zone 1+21 hazardous areas require equipment to meet both gas explosion-proof (Ex d ⅡC T4 Gb) and dust explosion-proof (Ex tD A21 IP65 T135℃) standards. Traditional equipment, unable to meet both types of explosion-proof requirements simultaneously, becomes a major source of safety hazards.
In sterile formulation filling workshops, the handling of vaccine raw materials must meet GMP Class 100 cleanliness standards. Manual operations are prone to contamination, and with a handling frequency of up to eight times per hour, fatigue leads to a more than 30% decrease in efficiency. After introducing explosion-proof latent AGVs, one company increased its handling efficiency to 16 times per hour and reduced the contamination rate from 0.5% to 0%.
The procurement cost of explosion-proof AGVs is 2-3 times that of ordinary AGVs. However, in the long run, they can reduce personnel exposure in hazardous areas by 100%, saving 46% in annual comprehensive costs (including labor and insurance). Nevertheless, companies often face increased costs due to unfamiliarity with explosion-proof certification processes, leading to selection errors or extended certification cycles.
The motor is the core component of an explosion-proof AGV, and its performance directly determines the equipment's explosion-proof capability and operational stability. The following dimensions should be prioritized during selection:
According to the GB/T 3836 standard, motor explosion-proof grades include Ex d (flameproof), Ex e (increased safety), Ex i (intrinsic safety), etc. In Zone 1 gas explosion areas, Ex d ⅡC T4 Gb-grade motors should be selected, as their flameproof enclosures can withstand internal explosion pressures and maintain surface temperatures ≤135℃. In Zone 21 dust explosion areas, additional Ex tD A21 certification is required to ensure dust cannot penetrate the motor.
Temperatures in traditional Chinese medicine extraction workshops can reach 80℃, requiring motors with T4-grade temperature resistance (surface temperature ≤135℃). One company once selected a T3-grade motor, which overheated and shut down in high-temperature environments, disrupting production continuity.
The motor's internal components should use spark-free materials (e.g., stainless steel, copper alloys), and the brake should be designed as a flameproof enclosure type (d-type) or structurally safe type (c-type) to prevent friction-induced sparks. Additionally, the motor should be equipped with conductive rubber tires to ensure static electricity is dissipated to the ground through the vehicle body, preventing static accumulation and explosion risks.
Modern explosion-proof AGVs need to seamlessly integrate with MES and WMS systems for multi-machine collaborative scheduling. Motors must support communication interfaces such as 485, CANopen, and EtherCAT to ensure real-time data interaction. For example, one company achieved simultaneous operation of 120 AGVs with an EtherCAT interface, with a scheduling response time ≤50ms.
Certification is the "final mile" in ensuring the compliance of explosion-proof AGVs, involving standard matching, type testing, factory inspections, and other steps. The following analysis uses CNEX certification as an example to explain the entire process:
The whole machine must simultaneously meet GB/T 3836 (explosion-proof standards), GB 5226.1 (mechanical electrical safety), and industry-specific standards (e.g., GMP standards for the pharmaceutical industry). For example, AGVs in sterile formulation filling workshops must pass GMP Class 100 cleanliness certification, with a surface finish Ra ≤0.8μm and the ability to withstand 121℃ high-temperature sterilization.
Type testing is the core of certification and must be conducted in a CNAS-accredited laboratory. Testing items include:
Certification authorities must dispatch personnel to inspect the factory's quality assurance system, including procurement control, production process control, and inspection equipment calibration. For example, it must be verified that motor suppliers hold Ex d ⅡC T4 Gb certification and that batch inspection reports are complete.
After passing type testing and factory inspections, companies can obtain explosion-proof certification, with the certificate number displayed on the product nameplate. Note that the EU market requires ATEX certification, and the North American market requires UL certification. Export companies should plan accordingly.
The deployment of explosion-proof AGVs should be implemented in stages based on workshop layout, process flow, and production rhythm:
Using 3D laser scanning technology, create a high-precision environmental map of the workshop, marking high-temperature equipment, gas leakage points, narrow aisles, and other risk areas. For example, one company discovered through surveys that the ethanol storage area in an API synthesis workshop posed a risk of excessive gas concentration, requiring AGV path planning to avoid the area.
Install explosion-proof AGV bodies and explosion-proof wireless APs to ensure full signal coverage in operational areas. Debug the navigation system to ensure positioning accuracy ≤±5mm and docking accuracy ≤±2mm. For example, in sterile formulation filling workshops, AGVs must dock automatically with production lines with an error ≤±2mm to avoid contamination risks.
Complete the integration of the AGV scheduling system with DCS and MES systems for real-time production data interaction. For example, one company achieved联动 control (linked control) between AGVs and reaction vessels, automatically stopping raw material handling when vessel temperatures exceeded standards to prevent accident escalation.
Adopt a phased go-live approach, initially replacing one-third of manual operations to observe performance. Optimize path planning and scheduling algorithms based on actual data to improve transfer efficiency. For example, one company reduced the average AGV transfer time from 5 minutes to 3 minutes after 30 days of trial operation.
In the electrical system of explosion-proof AGVs, the industrial computer acts as the "intelligent brain." Take the USR-EG628 as an example: based on the ARM Cortex-A53 architecture, it features 1 TOPS AI computing power and can simultaneously handle navigation, scheduling, and monitoring tasks. Its core advantages include:
