The autoclave, also known as a steam curing oven or pressure steam oven, is a large-scale pressure vessel with substantial size and weight, classified as special equipment. It provides stable steam curing conditions for materials through high-temperature and high-pressure steam environments, and is widely used in the fields of building materials and industrial production.
main application
In the building materials industry, this equipment serves as the core autoclave curing system for products including aerated concrete blocks, concrete pipe piles, fly ash sand bricks, coal ash bricks, micro-porous calcium silicate boards, and high-strength gypsum. The process facilitates the hydrothermal reaction of CaO—SiO₂—H₂O within the autoclave, achieving material gelation, solidification, and strength enhancement.
Industrial and other fields: Suitable for vulcanization of rubber products, wood drying and anti-corrosion treatment, heavy metal smelting, fire-resistant brick oil and coal infiltration, glass fiber steam curing, high-pressure treatment of chemical fiber products, high-temperature and high-pressure sterilization of canned food, pulp cooking, cable vulcanization, fishing net shaping, etc., covering chemical industry, medicine, aerospace, textile industry and other industries.
The main structure of the autoclave can be divided into the following key parts:
The vessel body assembly, formed by welding the cylinder and the vessel body flange, serves as the main container for materials. The bottom of the vessel body is equipped with tracks for steam curing trolleys, while the upper section features pipe seats for steam inlet and outlet, condensate drainage, and temperature and pressure instrument interfaces.
The pot cover is fabricated from a single 16MnR steel plate and achieves airtight sealing with the pot body flange (16Mn integral forging) through gear meshing. Featuring a quick-opening gear mechanism, it supports multiple drive options including manual (hand-cranked gearbox), electric, pneumatic, and hydraulic systems to accommodate diverse operational requirements.
Sealing and Safety Mechanisms: The reactor door employs specialized rubber sealing rings (e.g., nitrile rubber, EPDM rubber) embedded in the flange sealing groove. These rings achieve self-sealing through steam pressure, ensuring leak-proof operation under high-pressure conditions. Safety features include a triple interlock system (electronic interlock, manual screw interlock, hand-cranked reducer interlock), a safety valve (overpressure relief), a pressure gauge (real-time pressure monitoring), and a temperature sensor (temperature monitoring), effectively preventing operational errors and overpressure risks.
Support System: The reactor vessel is supported through a combination of fixed supports, movable supports, and end-specific supports. The movable supports allow free thermal expansion to prevent deformation. The support layout follows the principle of “approximately 3/5 of the vessel length between supports”. When not in use, four additional supports (with spacing ≤2.5m) should be installed, and anti-corrosion measures should be implemented.
Auxiliary equipment: including drainage device (drainage valve, dirt tank, used for condensate drainage), electrical control box (integrated temperature, pressure control and alarm function, to achieve automatic operation).
Key performance features
Strict material and manufacturing standards: The reactor vessel and lid are made of 16MnR special steel plates (GB6654 compliant), with flanges meeting JB4726-2000 Grade II standards. All pressure-bearing components undergo 100% X-ray radiography inspection (JB/T4730.3-2005 standard) to ensure welding quality and structural integrity.
Quick-opening structure and convenient operation: The gear quick-opening design greatly reduces the opening and closing time and improves production efficiency; there are various driving methods, among which the turbine worm gear reducer has higher transmission efficiency and stability than the traditional cycloidal needle gear reducer.
Energy-efficient design: The insulation layer of the kettle body adopts high-quality insulation materials to reduce heat loss; the steam distribution pipe and guide rail are optimized to ensure uniform steam distribution and improve the consistency of material maintenance 156.
High adaptability to specifications: Common sizes include Φ2×21m (capable of holding 20,000 standard bricks or 28.8 cubic meters of aerated concrete blocks) and Φ2×31m (capable of holding 30,000 standard bricks or 39 cubic meters of aerated concrete blocks), with customization options based on production scale. Key design features such as furnace wall thickness (14mm, 16mm), matching anchor bolts (24mm with threaded caps), and base plates (20mm) balance structural strength with transport efficiency.
Overview of working principle The working process of autoclave is mainly divided into the following stages:
Feeding stage: load the material to be cured (such as aerated concrete blocks) onto the steam curing cart, push it into the boiler and close the door.
Temperature and pressure increase stage: High-temperature saturated steam is injected into the reactor through the steam supply system to gradually increase the temperature (usually up to 190-200℃) and pressure (working pressure of about 1.3MPa), so that the hydrothermal reaction occurs in the material.
Constant temperature and pressure curing stage: maintain temperature and pressure stable (about 6-12 hours, depending on the material), to ensure that the material is fully cured and strength development.
Cooling and depressurization stage: stop steam supply, slowly discharge steam from the kettle through the exhaust system, and open the kettle door to remove the material after the pressure drops to atmospheric pressure.
Post-processing stage: The cured material undergoes cutting, packaging, and other subsequent operations to complete the production process.