Introduction to Granulator

The particle collector, also known as the slag collector, is an essential equipment for the blowing and cleaning of the steam system of the reheating unit to prevent damage to the turbine blades caused by debris and rust generated in the steam system and pipelines during manufacturing, transportation, storage, and construction, which affects the safety and economic operation of the unit.

The blowing of steam systems is usually carried out in stages. In order to prevent dirt from blowing into the reheater in the superheater system, blow and clean the superheater system.

During the start-up of the unit, steam flushing is required to ensure the safe operation of the turbine equipment.

After the temporary blow pipe control door, a particle collector is installed, and the industrial waste in the pipeline is recycled and discharged from the sewage discharge device, which can prevent industrial waste from entering the relevant area.

Scope of application of particle collector:

The particle collector is suitable for related pipeline systems such as superheaters, main steam pipelines, superheaters, and reheaters.

The Ministry of Electric Power Industry proposed to finalize the draft after extensive discussions from all relevant parties. The main content includes blowing scope, standards, parameters, methods, construction requirements, and safety precautions. The application of pressure difference method in blowing process, calculation of exhaust pipe reaction force, selection and design of target plate device and particle collector have been included in the appendix.

When the reheat unit adopts the step-by-step blowing method, a particle collector must be installed on the reheat steam cold pipe.

The particle collector should meet the following conditions:

1. The strength meets the requirements of steam parameters, with a design pressure of not less than 3MPa and a temperature of 450 ℃.

2. The resistance is small and dry at 0.1MPa.

3. Collect miscellaneous items - can. The aperture of the filter should not exceed 12mm, and the main steam flow should not blow directly into the mesh, and there should be enough space to collect debris.

4. The installation position of the particle collector should be installed at the inlet of the reheater as much as possible.

5. The design of the particle collector should have a compact and reasonable structure, easy production and installation, etc.

Design diagram of particle collector

Design diagram of particle collector and slag collector

Design process diagram of particle collector

Process design diagram of particle collector and slag collector

The manufacturing standards for particle collectors and slag collectors are as follows:

a) Made according to the Steel Pressure Vessel Standard

b) According to GB12349-94 standard and DCT5047-95 Technical Specification for Construction and Acceptance of Electric Power Construction-

c) According to the "Manual for Starting Steam Blowing of Thermal Power Units" 1998 edition-

d) Welding process shall be in accordance with Welding Procedure Qualification-

e) According to the "Adjustment and Trial Operation of Thermal Power Engineering - Inspection and Evaluation Standards"-

f) According to DT/L852-2004 Boiler Startup and Debugging Manual.

Technical and Processing 5. Design and Manufacturing Instructions for Particle Collectors and Slag Collectors

1. The assembly welding joints between the collector and slag collector pipes should be inspected according to the "Welding Technical Regulations for Thermal Power Plants".

2. Strengthen the uniform arrangement of the guide rib plate in the circumferential direction, and the pipe welding needs to be insulated.

3. The diameter of the hole holes on the orifice plate is the axial spacing and circumferential opening. The holes are arranged in a staggered manner and should be polished clean without leaving any debris such as iron filings.

4. The flange and blocking plate of the slag collection port should be kept tight.

5. All technical information required for equipment supervision and inspection (including materials, material inspection, welding, heat treatment, processing, energy inspection, etc., as well as damage inspection reports and instructions according to pressure vessel inspection) should be provided for the particle collector and slag collector before leaving the factory.

Particle collector--

Collect debris. The diameter of the waste collector should not be less than DN200. The outlet of the waste collector should be equipped with flanges and flange blocking plates of the same pressure, ensuring strict operation. The aperture of the filter should not exceed 12mm and there should be sufficient space for collecting debris, ensuring safe use.

Selection of equipment and devices for particle and slag collectors