February 9, 2022

What are the options for water mist dust removal and dust suppression nozzles?

The selection range of water mist dust removal nozzles is actually very large. For example, there are dust removal in different areas such as flue gas dust removal, the crushing area of ​​the discharge area of ​​coal and stone plants, and dust removal in textile workshops. Although all involved are dust particles , but its particles are large and small, and the concentration is also large and small. In view of these situations, it is not easy to choose the so-called good atomized nozzle to spray dust and remove dust.

Understand droplet size first

Droplet size refers to the size of a single droplet including the jetting pattern of the nozzle. Each spray style offers a range of placement sizes. This range is the descending size distribution.
There are many factors that affect droplet size: liquid properties, nozzle capacity, spray pressure and spray angle.

The law of droplet size

Air atomizing nozzles produce small droplet sizes, followed by fine spray nozzles, hollow cone nozzles, fan nozzles and solid cone nozzles
– Higher pressure produces smaller droplets, lower pressure produces larger droplets
-Low flow nozzles produce relatively smallest droplets, high flow nozzles produce relatively largest droplets
– Increased surface tension and increased droplet size
– Droplet velocity depends on droplet size. Small water droplets may have a high initial velocity, but the velocity will decrease rapidly. Larger droplets maintain their velocity longer and travel farther.

Nozzle Type: Hydraulic Atomization and Air Atomization

In most operations, droplets smaller than 200 μm did a better job of suppressing airborne dust particles, which were also small. The water is broken up into very small particles, reducing the surface tension and increasing the number of water droplets in the corresponding area.
Atomization is accomplished by passing water through nozzles at high pressure from a pump, or using a combination of compressed air and water pumped at low pressure to create very small droplets or mist. Air atomizing nozzles have the advantage of producing smaller droplets, however, in some operations, the cost of installing and operating compressed air can be prohibitive. Hydraulic fine mist nozzles are widely used and provide satisfactory performance in many operations.

Advantages and disadvantages of sprinkler types

For dust protection, standard hydraulic nozzles are usually used, producing droplets ranging from 200 to 1200 μm.
To suppress dust in the air, use air atomizing nozzles or hydraulic fine nozzles that generate water droplets of 20 to 200 μm.

Spray mode selection

Operating conditions determine which nozzle type and spray pattern are suitable. These guidelines provide an overview that can help you narrow down your options, but be sure to consult the performance table and droplet size data to refine your selection.

Hollow cone nozzle features:

– Ring water
-Large nozzle holes reduce clogging
– Small droplet size – usually smaller than other nozzle types
– Usually used where dust is widely distributed
– Widely used for dustproof

Fan nozzle features:

– Tapered edge, rectangular or uniform spray pattern
– Small and medium droplets
– Usually used in narrow or rectangular confined spaces
– Widely used for dustproof

Solid cone nozzle features:

-Circular jet pattern
– long distance high speed
-Medium to large size droplets
– Usually used when nozzles must be kept away from areas that need to be dust-proofed or clear of mechanical structures
– Widely used for dustproof

Air atomizing nozzle features:

– Choice of spray patterns – round, full and flat
– very small droplets
– Typically used to capture small dust particles in enclosed areas to reduce drift
– Widely used for air dust suppression

Features of fine atomizing nozzle:

-Hollow cone spray pattern
– very small droplets
– Typically used to capture small dust particles in enclosed areas to reduce drift
– Widely used for air dust suppression and jobs requiring light mist