Jiangsu Haifa Machinery Manufacturing Co., Ltd.

For the 3.2 million tons/yearized coking, CDQ (Coke Dry Quenching) unit, and DCU (Delayed Coking Unit) high hydraulic coke-cutting system, our company has adopted the API 610 BB5 radially split barrel-type multistage centrifugal pump structure for design and development. The pump has a design flow rate of 390 m³/h, a of 3750 m, is equipped with a 5500 kW high-speed motor, features a 12-stage impeller structure, and operates at a speed of 4300 r/min, meeting the requirements for high pressure, energy density, and frequent operating condition switching. By adopting variable-speed coke-cutting technology, the pump unit achieves no-load start-up, automatic pressure regulation, and precise matching of the coke-cutting process, effectively reducing the impact of coke powder particles on the impellers, diffusers, and sealing system, thereby improving operational stability of the unit.

I. Operating Characteristics of the Coke-Cutting Water Pump in the Delayed Coking Unit
The delayed coking unit an important facility in refining enterprises for deep processing of heavy oil, among which the high-pressure hydraulic coke-cutting system undertakes the critical task of coke. The coke-cutting water pump for the 3 million tons/year delayed coking unit has the following technical characteristics:

| Parameter | Value |
|---|---|
| Delivery medium | Wastewater containing coke powder |
| rate | 390 m³/h |
| | 3750 m |
| Number of pump stages |  |
| Speed | 4300 r/min |
| power | 5500 kW |
| Operating | Pre-flushing, drilling, coke cutting, recirculation |

Due to issues such as rapid pressure changes, frequent flow switching, and solid particles in the medium during the coke-cutting process, conventionalistage pumps are prone to problems including impeller wear, rotor vibration, seal failure, and efficiency degradation. Therefore, high-pressure coke-cutting water pumps typically adopt the highly reliable BB5 structural configuration. The API 610 BB5 pump features a radially split, double-casing, multistage impeller, and integral cartridge pull-out design, making it suitable for high-pressure continuous operation applications.

II. Structural Design of the API  BB5 High-Pressure Coke-Cutting Water Pump
Given the high head, high power, and high speed characteristics of the coke-cutting water pump, a radially split barrel-type BB5 structure has been adopted. The main design features include:

1. Multistage High-Pressure Rotor Design

The pump employs 12 stages of impellers arranged in series, achieving a high head output of 3750 m through multistage pressurization. Compared to single-stage high-speed pump solutions, the multistage BB5 structure offers: reduced single-stage head with distributed hydraulic loading; more balanced rotor forces; lower operational vibration; and longer maintenance intervals.

1. High-Rigidity Long Shaft System Design

As the pump shaft length reaches 3.1 m and the operating speed reaches 4300 r/min, higher requirements are placed on shaft system stability. The design incorporates: high-strength alloy steel pump shaft; precision rotor dynamic balancing; optimized bearing span; and controlled shaft deflection and critical speeds—ensuring rotor stability under high-speed operating conditions.

1. High-Reliability Sealing SystemIn response to the characteristics of the coke-powder-containing medium, mechanical seal design per the API 682 standard has been adopted. Through rational configuration of: flushing schemes; cooling systems; and seal chamber structure, the risk of coke powder entering the seal faces is reduced, thereby extending seal service life.

III. Variable-Speed Coke-Cutting Technology to Reduce Coke Powder Impact Traditional coke-cutting systems typically operate constant-speed pumps with valve-based pressure regulation, which readily causes: increased throttling losses; prolonged pump operation away from the high-efficiency zone; and high-velocity erosion of flow-passing components by coke powder. This project adopts variable-speed drive technology, automatically adjusting pump speed according to the coke-cutting stage:

1. Pre-flushing stage: reduced speed for low-pressure, high-flow water supply.

2. Drilling stage: increased pressure for stable drilling.

3. Coke-cutting stage: automatic output pressure adjustment based on bed resistance to improve cutting efficiency.

4. Recirculation stage: reduced load for energy-saving operation.

Variable-speed control not only reduces energy consumption but also minimizes high-velocity impact of coke powder on impellers and diffusers, extending the service life of pump flow-passing components.

. Technical Breakthroughs in Domestically Manufactured High-Pressure Coke-Cutting Water Pumps
In past, high-pressure coke-cutting water pumps for large refining and petrochemical enterprises relied heavily on imported brands, primarily due to: the difficulty of ultra-high head design; stringent high-speed rotor stability requirements; multistage hydraulic models; and demanding dynamic analysis of long shaft systems. Jiangsu Haifa Machinery Manufacturing Co., Ltd., leveraging its API 610 high-pressure multistage pump design and capabilities, has achieved the domestic development of high-pressure coke-cutting water pumps. product portfolio covers:

1. API 610 BB5 high-pressure barrel-type pumps;




2. High-pressure water injection pumps;




3. Refinery process pumps;




4. Coke slurry pumps;




5. Petrochemical high-energy pump units.

Through hydraulic optimization, rotor dynamics analysis, and high-speed machining and manufacturing technologies, the reliability domestically manufactured high-pressure pumps has been improved.

V. Application Value
The domestic application of the high-pressure coke-cutting water for the 3 million tons/year delayed coking unit can achieve: replacement of imported high-end pump equipment; reduced equipment procurement and maintenance costs; enhanced operational support capability of refining units; and independent control of critical equipment. In the future, high-pressure coke-cutting water pumps continue to play an important role in large-scale oil refining, coal chemical, and petrochemical fields.

Technical Reference Standards

1. API 610: Centrifugal Pumps for Petroleum, Petrochemical and Natural Gas.




2. API 682:umps—Shaft Sealing Systems for Centrifugal and Rotary Pumps.




3. ISO 13709: Cental Pumps for Petroleum Petrochemical and Natural Gas.




4. GB/T 3216: Rotary dynamic pumps—Hydraulic performance acceptance tests.




5. GB/T 5657: Technical conditions for centrifugal pumps.




6. Hydraulic Institute Standards: Centrifugal Pump Design and Performance Standards.