What is air lock valve?
An Airlock is a valve that separates a pressure differential sealing off airflow from a hopper, bin, or conveying line. In the pneumatic conveying world airlocks are usually found at the beginning of a pressure system or at the end of a vacuum system.
How is rotary airlock capacity calculated?
To calculate the Rotary Airlock Valve Capacity, divide the rate of conveying by the product density, then divide the result by the valve efficiency, and finally divide that result by the rotor speed.
What is a star valve?
[′stär ‚valv] (food engineering) In a machine for preparing puffed foods, a thick wheel with vanes that rotates in a tight-fitting cylindrical casing and transfers the product from a higher pressure to a lower pressure, or vice versa. Also known as rotary lock.
What does air locked mean?
An air lock is a restriction of, or complete stoppage of liquid flow caused by vapour trapped in a high point of a liquid-filled pipe system. The gas, being less dense than the liquid, rises to any high points. This phenomenon is known as vapor lock, or air lock.
What is rotary air lock valve?
Rotary airlock valves are a critical component in many material handling systems. From dust collectors to pneumatic conveying systems, rotary airlocks not only control the feed rate but also minimize air leakage between equipment above and below the valve with differing levels of pressure or vacuum.
How does a rotary airlock valve work?
In an airlock valve, air is sealed (locked) between the inlet and outlet ports. This allows the materials to travel downward through the valve from the inlet to the outlet port while restricting the airflow. Material is moved continuously through the presence of a constant air pressure between the ports.
How do star valves work?
Rotary valves, also commonly called star valves, are therefore used at the beginning and at the end of pneumatic transports. They allow to bring the solid from a zone of low pressure to a zone of low pressure at the beginning of the line while helping to disengage the solid from the air flow a the end of the line.
What is a rotary valve used for?
(See blog article “What is a rotary valve?”) In industry, a rotary valve is used to regulate the flow of a product, usually to reduce the flow rate to a level more suitable to the process being undertaken.
What causes an air lock?
The main cause of an air lock in pipes is when pockets of air are trapped by the flowing water, preventing the free flow of water. Also, cold water pipes have less pressure compared to hot water pipes; as a result, it’s mainly hot water pipes that are affected by air locks.
What is an airlock rotary valve?
An airlock rotary valve, also called rotary valve feeder or star valve, is a mechanical conveying device that allows to control a bulk solids flow (powder, pellets, granules…). Such airlock feeders are often used prior to a pneumatic transport system. Learn more all details rotary valves in this webpage.
How much clearance is required for a rotary airlock valve?
Typical clearance for airlock rotary valves is 0.1 mm and usually ranges from 0.05mm to 0.25 mm depending on the service expected for the valve (high difference of pressure from each side of the valve or not).
What is the purpose of a reduced volume airlock?
Reduced volume is used to lower the capacity of the rotor. Smaller rotary airlocks may cause the material to bridge above the inlet. The reduced volume rotor allows a larger valve to be used to eliminate bridging and lower the discharge rate when you do not want to over feed the equipment downstream.
Why does the throughput of the airlock rotary valve decrease?
Important notice : the airlock rotary valve throughput is not linear. The throughput ceases to increase or can even decrease past a certain speed. It can be due to different causes, mainly it will be due to the reduced time for the pockets to be filled and empties.