Rotary Valve Types and Selection

Rotary valve belongs to star-like material feeding and discharge devices. The body usually consists of rotor wheel, shell, seals, gear box and electric motor.

l  Structure Types

According to mediae’s characteristics, application and use conditions, several structure installation types are available for choice.

Bearing-built-in Direct Connection Type:  A gear box is connected with main body directly. The design is compact and transmission efficiency is high. It is applicable for low temperature mediae and large-grain-size mediae.

Bearing-outboard Direct Connection Type:  A bearing is placed at the outer end of the end cover and keep some distance from material or media. It is applicable for high temperature mediae, easy leakage materials (e.g. ultrafine powder). The bearing has a long use life span.

Bearing-outboard Side Chain Type:  A sprocket is used for transmission. The gear box motor is sided and connected with the main body with a connection plate. It is featured with high transmission ratio, durability and easy maintenance and repair.

l  Rotor Wheel Types

According to different media’ characteristics, several rotor wheel types are available for choice.

                   (1)             (2)           (3)            (4)

   (1)：Open type rotor wheel

(2)：Inserted disc rotor wheel

(3)：Close type rotor wheel

(4)：Anti-adhesive rotor wheel

According to different pressure, the blade quantity is 6 pieces, 8 pieces, 10 pieces or 12 pieces for choice.

l  Construction Material

The main body can be made of stainless steel, carbon steel, cast iron, cast steel, ductile cast iron, cast aluminium, cast copper and etc.

l  Driven Power

According to different requirements, there are ordinary motor, freqency inverter motor and explosion-proof motor for choice.

l  Application Field

A rotary valve is widely used in petrochemicals, electric power, metallurgy, mine, grain and oil, foodstuff, fodder, medicine, building material, tobacco, wood, casting, textile, drying, dust-proof and other industries.

When it is used at the bottom of a feed bin, the material fall down by gravity and fill in the space between blades of the rotor wheel of the rotary valve. Then it rotates together with the blades, finally falls down at the lower position. In this way, quantitative and continuous material discharge can be realized.

In the positive pressure and negative pressure pneumatic conveying system, a rotary valve can feed material evenly and continuously to a transport pipe to ensure stable flow rate of solid and gas. At the same time, it can cut gas from the top side to lower side of the discharger, therefore it can lock gas and make pneumatic conveying can be working smoothly.

l  Output (discharge output) G Calculation Formula

G=0.06V.N.Y.R.K (ton/hr)

V: volume (L/r)     N: rotary speed (r/min.)

Y: volume efficiency (granule material value 0.8, powder material 0.5-0.6)

R: bulk density (ton/m³)

K: correction ratio (usually value 0.7-0.8)

l  Model Selection

In order to select a suitable model for you, please inform us:

1.    Construction material --- cast iron, carbon steel, stainless steel, aluminium, copper or alloy.

2.    Conveyed material’s property—grain size, moisture content, bulk density, angle of test, and ect.

3.    Application--- positive pressure conveying, negative pressure conveying and pressure difference between top and bottom blades.

4.    Conveying capacity---- discharge output per hour, is a quantitative conveying  needed?

5.    Speed ratio of a gear box, the protection grade of electric motor. Is an adjustable speed or inverted frequency needed?

6.    Installation dimensions.