[Haichuan Illustrated Chemical Equipment] Series Posts -- Reciprocating Compressor Concentric Ring Combined Valve
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Get to know equipment, understand it, and make good use of it. [Haichuan’s Illustrated Guide to Chemical Equipment] series posts: https://bbs.hcbbs.com/forum.php?mod=viewthread&tid=5719196. Everyone is welcome to participate in the discussions. ----------------------------------------------------------- In the world of reciprocating compressors, if the cylinder is considered the working chamber and the piston the driving force, then the valve serves as the mechanism that controls the flow of gas in and out. Among the various valve designs, the combined valve, and in particular the concentric ring valve, is undoubtedly a prime example of the perfect integration of \"space utilization\" and \"fluid dynamics\" in mechanical design. As a senior chemical engineering engineer, you are certainly aware that in high-speed or high-pressure compressors (such as large-scale process gas compressors and refrigeration compressors), the space on the cylinder head is extremely limited. If the intake valve and the exhaust valve are arranged separately, it often results in an insufficient flow area for the valves or an excessive clearance volume, thereby significantly reducing the volumetric efficiency of the compressor.
The combined valve integrates the intake valve and the exhaust valve into one, mounted on the same valve seat. It usually adopts a concentric ring structure: Common Valve Seat: This is a thick metal disc with multiple concentric circular channels. Some channels are for intake, while others are for exhaust. Suction Plate & Springs: Usually located in the outer ring. It consists of one or several rings of valve plates, supported by micro springs below. When a negative pressure is created inside the cylinder, external gas overcomes the spring force to push the valve plate open and enter the cylinder. Discharge Plate & Springs: Usually located in the inner ring (sometimes the positions are reversed, depending on the specific design). It also features a ring-shaped valve disc and spring structure. When the gas in the cylinder is compressed to high pressure, it pushes against the valve disc and is discharged. Lift limiter/protective cover (Valve Guard): Located at the top, it is used to limit the maximum height (lift) to which the valve disc can open, and it also houses the spring. Center Bolt: It holds all the aforementioned components tightly together, like in a hamburger, and locks them onto the cylinder head. Working principle: Precise coordination between breaths. Inflation stroke: The piston moves downward, increasing the volume inside the cylinder and reducing the pressure. When the pressure inside the cylinder is lower than the pressure in the intake network, the pressure difference overcomes the elastic force of the outer-ring intake spring, causing the outer-ring intake valve to open downward (toward the cylinder), allowing fresh gas to flow in. At this time, the inner ring exhaust valve disc is firmly pressed against the valve seat by the high pressure in the exhaust system, keeping it closed. Compression and exhaust strokes: The piston moves upward, compressing the gas and causing the pressure to rise sharply. The intake valve flap closes rapidly under the action of spring force and cylinder pressure. When the pressure inside the cylinder exceeds the pressure in the exhaust system, the pressure difference pushes open the inner exhaust spring, causing the inner exhaust valve flap to open upward (toward the outside of the cylinder), allowing high-pressure gas to be discharged. Advantages of the combined valve: Large flow area: It occupies the entire cylinder head area, thereby significantly reducing the flow resistance for gas in and out. Small clearance volume: The compact design improves the volumetric efficiency of the compressor.
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【Ten Years of Rapid Development in Chemical Engineering Equipment】The country’s first inland hydrogen-powered container ship entered service in 3131–2026: https://bbs.hcbbs.com/forum.php?mod=viewthread&tid=5720953 (Source: Haichuan Chemical Industry Forum (HCBBS))