NFPA design valves are custom applied units to your specific application. “Speed" engineers review the application and evaluate the design based on KST values for the material, temperature, pressure and ambient conditions.
Material selection: carbon steel, stainless steel 304，stainless steel 316
USDA Dairy Accepted line of Rotary Airlocks are designed for use in sanitary applications in the food, dairy, pharmaceutical and chemical industries where regular cleaning is required to prevent product contamination.The product contact surfaces of the airlock are manufactured in 316 Stainless Steel and polished to a 150 grit finish, ensuring that there are no lodgement points allowing the product to flow smoothly.
A1、The rotary valve is also called unloader valve, rotary feeder, air-lock valve. The structure of star discharge (as shown in Figure 1) is composed of a rotor impeller with several blades, a casing, a seal and a reducer, Motor and other components.
When the material in the upper silo falls by its own weight and fills the gap between the blades, it is discharged in the lower part as the blades rotate. Therefore, the rotary valve can discharge quantitatively and continuously (as shown in Figure 2).
Discharge of rotary valve equipment Presentation
1. The discharger has the same inlet and outlet installation dimensions, upper and lower flange connection, flange standard, upper feed and lower discharge, and the motor reducer side is directly connected to the host through a connecting plate and driven by a parallel sprocket. The impeller is controlled to rotate in the machine body through the stepless speed regulation of the motor. The powder material falling from the upper silo enters the impeller compartment through the feed port, and is discharged from the discharge port as the impeller rotates
2. The parts of the discharger are made of SS403/SS316/ carbon steel. The blades and the inner surface of the discharger are finished with a boring machine and internal grinding to keep the contact surface of the whole valve body smooth and the gap accurate, ensuring good long-term operation. Sealing performance, no leakage, no gas leakage. The shaft end is sealed with nitrogen tetrafluoride packing to prevent leakage of air and materials.
3.Special design components:
A、 Rotor form: closed rotor; small capacity rotor; adjustable and replaceable rotor; sharpened rotor; hardened, wear-resistant rotor.
B、Shaft seal: air seal; packing seal; labyrinth combination seal.
C、Exhaust holes: standard exhaust holes; special exhaust holes.
D、Special reducer; special motor (frequency conversion motor, explosion-proof motor, speed-regulating motor
E、Other special requirements
4. The upper and lower flange openings of the unloader are basically square or round, and can also be selected by the user.
5.The code w of the external bearing type indicates that the bearings at both ends are isolated from the impeller to prevent the ultra-fine powder from contacting the bearing. It is usually also used as a high-temperature resistant type with a temperature resistance of 280 ° C
6.The discharge volume is calculated by the following formula.
G=0.06V • N ■ Y • R • K (t/ h)
V-off fan volume (liter / rev)
N-off fan speed (r/ min)
Y-off fan volumetric efficiency (0.5-0.8)
R-material capacity (t / m3)
1 Design and development, The company's R&D team designs according to needs, and can develop manufacturing processes and skills according to the design concept
2 Open the mold, decide the product mold and pour the valve body according to the design drawings and R&D process
3 out of the rough, the first class foundry has been fixed for more than 15 years of cooperation, and the rough parts are produced according to the actual amount
4 boring machine processing, after roughing through rough lathe, precision boring valve body cavity and upper and lower surface flanges by precision CNC machining center
5 Polishing and polishing, professional grinding personnel polish the valve body and various accessories to the mirror surface
6 Precision welding, for all kinds of non-standard parts, a professional welder team accurately welds according to the design drawings
7 Finishing machine, various machining centers and outsourcing finish the surface of the valve body within 10 wires
8 Locksmiths, various CNC drilling machines and tapping machines make precise holes in the valve body and accessories to ensure accurate dimensions
9 Fine drilling, the company purchases a German imported tapping machine to drill and tap the connecting parts of the product to ensure the accuracy of the size
10 Assembly, quick and accurate installation by assembly workers who have worked for more than ten years
11 Commissioning, perform various data debugging on the overall operating parameters of the valve before leaving the factory, and after the developed quality certificate under the QC department is approved to leave the factory to ensure that the customer's needs are met and qualified shipments are given
Application: It is suitable for powder and small particle materials, and separates and discharges materials in the process of positive and negative pressure difference. It is used in chemical, food, cement, pharmaceutical, drying, environmental protection, power and other industries
Note: This article only lists the standard model parameters. If there is a non-standard design, please confirm the size and material with the manufacturer or the design section.