What is an explosion-proof overhead traveling crane? Determination of applicable boundaries
The standard model LB for explosion-proof overhead travelling cranes refers to overhead travelling lifting equipment operating on rails. Different from general overhead travelling cranes, its complete lifting mechanism, operating motors, electric control boxes, limit devices and wiring components all adopt flameproof explosion-proof structures to restrain outward diffusion of electric arcs and sparks and prevent ignition of explosive media in the environment.
Preferred application scenarios:
petrochemical plants, paint production workshops, coal chemical plant areas, grain and oil flour processing facilities, aluminum/magnesium powder workshops, hazardous chemical warehouses, and flammable and explosive sections in pharmaceutical manufacturing.
Core Procurement Principles:
First determine the classification of hazardous explosive areas, then match the corresponding explosion-proof grades. Unauthorized modification of general purpose cranes for explosion-proof applications is prohibited.
Identification of Hardware Configuration for Formal Industrial-Grade Explosion-Proof Overhead Bridge Cranes
A large number of low-cost explosion-proof lifting equipment available on the market are commonly assembled by combining standard main units with simple explosion-proof enclosures, which poses serious potential safety hazards.
The configuration standards for certified formal explosion-proof models are specified as follows:
- Core driving components: Motors and brakes must hold separate explosion-proof certificates. Simple retrofitting by fitting ordinary motors with external enclosures is prohibited.
- Electrical system: All wiring chambers and cable entry devices shall adopt flameproof sealing structures to prevent internal electric arcs from leaking out. Explosion-proof flame-retardant cables shall be used.
- Structural components: Main girders shall be formed by box-section welding with weld seam flaw detection. Wheels for the main trolley and auxiliary trolley shall be made of friction-spark-resistant materials to avert open flames caused by metal impact.
- Complete set of qualification documents: Explosion-proof certificate for the complete machine, type test certificate for special equipment, and production license. Each equipment unit is matched with a dedicated certificate, applicable for safety supervision inspections and hazardous chemical project reviews.
Exclusive Solutions for Mainstream Subdivided Working Conditions
Chemical Raw Material Production Workshop (Gas Explosion-Proof)
Adopt Exdll BT4/CT4 gas explosion-proof model equipped with explosion-proof wireless remote control, enabling long-distance operation and reducing personnel's close contact with hazardous media.
Flour, aluminum powder and graphite powder processing plant (dust explosion protection)
Select EXtD IIID dust-explosion-proof overhead travelling crane and strengthen the sealing structure to prevent dust from accumulating inside electrical enclosures.
Workshop for Storage of Pharmaceuticals, Paints and Solvents
Equipped with a variable frequency explosion-proof system to reduce start-stop impact. The complete machine adopts enhanced anti-corrosion technology to resist corrosion from volatile chemical media.
Small and Medium-Sized Hazardous Chemicals Warehouses
Medium-tonnage LB explosion-proof single-girder overhead cranes require moderate investment and can meet the demands of intermittent cargo loading, unloading and transportation.
Core Parameters of Explosion-proof Overhead Crane
| NO. | Core Parameter Dimensions | Selection Specifications and Standard Requirements |
|---|---|---|
| 1 | Rated Lifting Capacity | 5–300T |
| 2 | Span | 7.5–31.5m |
| 3 | Lifting Height | 6–30m |
| 4 | Working Class | A3–A5 |
| 5 | Explosion-proof Classification | For gas explosive atmosphere：Exdll BT4/Exdll CT4 For dust explosive atmosphere：ExtD IIID |
| 6 | Protection Class | IP55 |
| 7 | Power Supply Voltage | 380v/50Hz/3P (Custom voltage available) |
| 8 | Operation Mode | Handle control / remote control |
| 9 | Safety Configuration | Standard equipped with explosion-proof overload limiter, lifting/travel limit switches, buffer, emergency stop circuit and complete set of safety interlock devices. |
| 10 | Electrical Control System | Full set of flameproof motors, flameproof terminal boxes and explosion-proof limit switches |
Frequent Pitfall Avoidance Guide for Procurement
Pitfall of Modified Equipment
Procurement of modified equipment fitted with "explosion-proof accessories retrofitted to ordinary vehicles" is prohibited. Modified equipment models cannot pass explosion-proof testing. Liability cannot be determined if safety accidents occur, and the work will directly fail safety supervision acceptance.
Pitfall of Vague Explosion-proof Ratings
The complete explosion-proof marks such as Exdll BT4, Exdll CT4 or dust explosion-proof ratings must be clearly specified in writing in the procurement contract. Vague descriptions like "universal explosion-proof model" shall be rejected to prevent downgrading of delivered configurations.
Pitfall of Missing Qualifications
Require manufacturers to provide the complete machine explosion-proof certificate and copies of certificates for all explosion-proof components, and verify that the model numbers on the certificates match those of the equipment one by one. Some suppliers use certificates of other equipment models, which cannot be used for project inspection and submission.
Specification for Standardized Installation & Acceptance of Henan Mine
After the completion of equipment installation, carry out the full acceptance procedure: no-load trial operation, half-load, full-load and overload performance tests. Inspect the sealing of flameproof enclosures, limit sensitivity and the effectiveness of interlock protection item by item.
List of delivery documents: general assembly drawing of equipment, flameproof certificate, type test report, operation and maintenance manual, and list of flameproof components. All documents shall be used for the safety standardization assessment of hazardous chemical enterprises.
The complete machine of Henan Mine Crane flameproof overhead travelling crane enjoys a 1-year warranty, and core components such as flameproof motors and flameproof electrical control systems are eligible for extended warranty. Regular safety inspection services for flameproof equipment are provided to guide enterprises on standard daily flameproof maintenance. Remote technical support is available, and the complete set of documents supports certification for export projects.
Henan Mine's Reliable After-sales Service System
Mine Hoisting holds complete production qualifications for explosion-proof hoisting equipment and can provide one-stop services including on-site plant survey, hazardous working condition analysis, load checking calculation, customized solution design, manufacturing, installation, acceptance and training.
If you have planning requirements for lifting equipment in chemical, powder and hazardous chemical workshops, please provide workshop parameters, medium types and hazardous area classifications and contact Henan Mine Chloe for a free complete set of technical solutions for explosion-proof lifting equipment and formal quotations.
Contact: Chloe
Tel: +86 18238799707 (Same number for WhatsApp)
Email:sales07@minehenancranes.com
FAQs
Q: What is the biggest difference between an explosion-proof overhead traveling crane and an ordinary overhead traveling crane?
A: The core difference lies in that all electrical systems and friction components adopt flameproof spark suppression design. Sparks generated by the electrical equipment of ordinary traveling cranes will be directly released into the environment, so such cranes cannot be used in flammable and explosive areas. Explosion-proof models can prevent ignition sources from spreading and meet mandatory safety specifications for hazardous chemical workshops.
Q: How to choose between BT4 and CT4 explosion-proof grades?
A: Ex d Ⅱ BT4 is selected for most chemical workshops dealing with paints and solvents. If the medium contains highly hazardous substances such as hydrogen, acetylene and carbon disulfide, Ex d Ⅱ CT4 must be adopted. The selection shall be subject to the hazardous area classification report issued by the design institute.
Q: Is the explosion-proof wireless remote controller compliant?
A: It is necessary to select flameproof remote controllers with independent explosion-proof certificates, and the complete set of supporting equipment shall pass explosion-proof inspection. Ordinary industrial remote controllers shall not be installed without authorization.