STEEL INDUSTRY

Nozzles selection guide

How do you choose a nozzle? What to consider to make the right choice?

Nozzles selection guide

How do you choose a nozzle? What to consider to make the right choice?

The choice of a nozzle is a very important phase in the design of any plant: the right nozzle allows to optimize processes, save energy and economic resources and obtain better results.
Although the nozzles are in many cases the terminal part of a large plant, they can affect the entire upstream process. Your success therefore also depends on this choice.

Below we list the technical characteristics of a nozzle and also the types classified according to the distribution of the jet to help and support you in your choice. We are always available for personalized offers and to help you find the right nozzle for your needs.

Techniques for spray production

Many different techniques can be used to produce a spray, and most of them are used today for nozzles to be applied in industrial processes. Based on the different techniques, the following nozzle types can be used in industrial applications to generate a liquid spray.

1 | PRESSURE NOZZLES

This is the simplest type of nozzles, where an orifice is opened into a chamber where the liquid to be sprayed is fed under pressure. A spray is produced through the orifice with spray pattern, flow rate and spray angle depending upon the orifice edge profile and the design of the inside pressure chamber.
Typical pressure nozzles are the flat jet nozzles series GA, J, GX and GY.

2 | TURBULENCE NOZZLES

In these nozzles the liquid moving towards the chamber preceding the orifice is given a rotational speed component, so as to open up in a conical shape as soon as it leaves the orifice edge because of centrifugal force. Based on the nozzle design and the technique used to generate the rotational speed, the drops produced can be confined to the cone outer surface (hollow cone spray) or be evenly distributed to fill the entire volume of the cone (full cone spray).

3 | IMPACT NOZZLES

Here the desired spray shape is obtained producing an impact of the liquid jet onto a properly designed surface. The liquid jet is subsequently changed into a fluid lamina and then broken into drops with the desired spray pattern after leaving the nozzle edge.

4 | AIR ASSISTED ATOMIZERS

Fine and very fine sprays can be obtained by means of air assisted atomizers, working upon various different principles.

Spray nozzles technical features

Before proceeding with the choice, several technical features shall be taken into consideration to select the correct nozzle for a given application:

1 | NOZZLE EFFICIENCY

A spray nozzle is a device that turns the pressure energy of a liquid flow into kinetic energy. The nozzle efficiency can be defined as the ratio between the energy available at the nozzle inlet and the energy wich is actually used to increase the liquid speed and create the spray. The nozzle efficiency varies between 55% and 95% for the types that are commonly used in industrial processes.

2 | DROPLETS SIZE

The droplets size depends on the structure of the atomizer, intensity of the liquids energy, liquid surface tension and density. The size of the atomized droplets is not uniform. Therefore, the average droplets size becomes an important factor.

3 | SPRAY ANGLE

A spray angle is the angle formed by the cone of liquid leaving a nozzle orifice. The spray angle and the distance between the nozzle orifice and the target surface to be covered determine the spray coverage.

4 | IMPACT FORCE

The impact force is the force generated by the jet of water deflected by the impact surface and its strength is often expressed in kg/cm2 or lb/inch2. The uniformity of a jet impact force and distribution influence the washing effect.

5 | DISTRIBUTION

Engineers design nozzles with different spray distribution patterns. Patterns can be solid stream, full cone, hollow cone, flat spray, spoon flat fan. The nozzle design aims at the uniformity and impact force of the jet sprayed whether nozzles are used individually or overlapping.

Types of nozzles

There are different types of nozzles classified according to the distribution of the jet. How to choose them? What are their characteristics?

FLAT FAN SPRAY PATTERN

In a flat jet spray the liquid droplets are sprayed in the shape of a flat liquid layer, with different thickness according to the principle used to generate the spray.

When and why choose a flat fan jet nozzle
A flat jet spray nozzle serves the purpose of spraying onto a surface or an object moving in a transverse direction with respect to the one of the jet surface, a typical example being the nozzles in a car washing tunnel.

FLAT FAN NOZZLESWASHINGCOOLINGOTHER APPLICATIONS
F
HIGH PRESSURE WASHING
Car washing
High pressure washers
Industrial cleaning
GA
SHORT BODY
Washing, cleaning filters in papermaking machines and dryersContinuous casting, product coolingChemical spraying, water curtains for toxic gas abatement. Excellent for piping, sewage and drain cleaning
GX
FLAT FAN NOZZLE TIPS
Cleaning of semiconductors and precision partsContinuous casting, product coolingSpraying lubricants and release agents, spraying flavorings, cooling oils and antifouling paints
GX
STANDARD AND LARGE CAPACITIES
Washing of fabric filters, parts, vehiclesCooling steel and productsSpraying lubricants and release agents, spraying antifouling paints
GY
DOVETAIL FLAT FAN TIPS
Steel washing, fabric filter washing, parts washingSteel cooling, product cooling
HT
QUICK-CONNECT FLAT FAN NOZZLES
Steel and PCB washing, fabric filter washingCooling steel and productsSurface pretreatment in painting plants, waste water treatment plants
J
LOW FLOW
Steel and PCB washing, glass washingCooling steel and productsPre-treatment in painting plants, waste water treatment plants
J
STANDARD CAPACITY
Parts washing, food washing, fabric filters washingCooling of metal parts and vehiclesSpraying of chemicals, disinfectants and lubricating fluids, water curtain for the separation of harmful gases, washing systems. In steel mills they are used in the pickling process to eliminate the superficial layers of oxides
J
LARGE CAPACITY
Tanks, parts and vehicle washingCooling parts and steelSpraying of chemicals, disinfectants and lubricants, water curtains for the separation of harmful gases, fire-fighting systems
K
LARGE SPRAY ANGLE
Washing fruit, vegetables, crushed stoneCooling of metal parts, bottlesSpraying of roller lubricant, release agents, coolants, foam dispersion, fire-fighting systems, water curtains.
K
HIGH IMPACT
Washing of parts, objects, crushed stone, roads, airplanes, vehicles and tanks
GE
DISC NOZZLES
Washing or spraying in paper mills, reticular fabrics washing, plants, water treatment, felts and cloth washing
GF
SELF-CLEANING NOZZLES
Washing or spraying in paper mills, washing fabric filters, water treatment systems

FULL CONE NOZZLES

Such spray pattern is commonly used in a large variety of industrial processes, since it is the one which allows to distribute in an even way the water flow onto a surface: the full cone spray pattern is therefore useful, as a typical example, to evenly spray cooling liquid on a still surface.

When and why choose a full cone nozzle
All full cone nozzles have unique applications suitable for any type of plant or process requirement.
A typical use is for example to distribute droplets uniformly in a certain volume, as in the case of a cooling tower.

FULL CONE NOZZLESWASHINGCOOLINGOTHER APPLICATIONS
AA
SHORT BODY
scrubber washing, washing vehicle parts and crushed stoneHigh temperature cooling, vehicle parts, tanksChemical spraying, seawater desalination
AE
FLANGE
Desulphurization, washing / scrubber towersCoke cooling, Gas cooling, High temperature cooling
AH
FINE MIST
Continuous casting
AT
TANGENTIAL
Washing / scrubber towers, parts washing, pretreatment in painting processes.Gas cooling, tank coolingDust suppression in mines and coal plants. Chemical spraying, fire protection systems design
BA / BCWashing towers, parts washing, pre-treatment in painting plantsCooling of drains, cooling of tanksDust suppression in mines and coal plants. Chemical spraying, fire-fighting systems
BB / BDWashing towers, parts washing, pre-treatment in painting plantsSmoke washing, exhaust cooling, tank coolingDust suppression in mines and coal plants. Chemical spraying, fire-fighting systems
BE / BGFood washing, parts washing, pre-treatment in painting processesSteel cooling, product cooling, tank coolingDesulphurization
BE / BLDesulphurization, coke cooling
BR / BS / BT / BUBottle washing, parts washing, deep cleaning
BV / BW
TANGENTIAL
Parts washing, gas washing, food washingParts cooling, gas cooling, tank cooling
BX / BJ
FLANGE
Steel washing, parts washing, pre-treatment in painting plantsContinuous casting cooling, product and tank coolingDust suppression in mines and coal plants, chemical spraying, leak tests
CH
CLUSTER NOZZLE
7 & 13 NOZZLES TYPE 
Tank washing, gas washingGas coolingFire-fighting systems, dust control, humidification
CAS
CLUSTER NOZZLE
Gas cooling at high temperaturesWater mist fire-fighting systems, exhaust gas treatment, dust control, humidification
CAY
WIDE SPRAY ANGLE
Tank washing, parts washingGas cooling at high temperaturesWatermist fire-fighting systems, exhaust gas treatment, dust suppression, humidification
DFood washing, parts washing, pre-treatment pre-paintingContinuous casting cooling, product cooling, tank coolingChemical spraying, leak tests, dust suppression in mines and coal plants
D
LARGE CAPACITY
Food washing, parts washing, pre-treatment in painting plantsContinuous casting cooling, product cooling, tank coolingDust suppression in mines and coal plants, chemical spraying, leak tests
E
STANDARD SPIRAL NOZZLES
Washing / scrubber towersGas coolingDesulfurization, chemical spraying, fire prevention and extinguishing
E-X
WIDE PASSAGE
Washing towersGas coolingDesulfurization, chemical spraying, fire prevention, fire extinguishing

HOLLOW CONE NOZZLES

A hollow cone spray pattern consists of droplets concentrated onto the outer surface of a conical shape volume, with no droplets contained in the inside of the conical jet shape.

When and why choose a hollow cone nozzle
These nozzles are normally used for smoke washing or gas cooling applications in several industrial processes.

HOLLOW CONE NOZZLESWASHINGCOOLINGOTHER APPLICATIONS
PA / PB
LARGE CAPACITY
Washing towers, desulfurization, denitrationHigh temperature gas cooling, product cooling
PN / PO / PSWashing towers, parts washing, surface pre-treatment in painting plants, dust and foam abatement, filter sprayingCable cooling, plastic tube coolingBeverage heating systems, humidification systems
PRWashing towersCoke coolingDesulphurization, denitration
RA
WITH VANE
Washing towers, washing partsCooling of gases, products, ductsDust control, air humidification and conditioning systems
RB
VANELESS
Washing towers, washing productsCooling of gases, products, ductsDust control, humidification systems, sterilization
RCWashing towers, small tanks, internal pipes and ductsPipe painting, dust control, fire prevention systems
RO
DEFLECTED SPRAY
Tank washing, washing towersFire extinction
RW / RX / RZWashing towersDust control, humidification, spray deodorization, spray disinfection

STRAIGHT JET NOZZLES

This is the general purpose flat jet nozzle, where the liquid enters the nozzle in line with the axis length and is fed to a pressure chamber, from where it is ejected through the nozzle orifice. Flow value and spray angle are determined respectively from the orifice cross section and the orifice edge profile.

When and why choose a straight jet nozzle
They are built to produce a stable and well-defined liquid jet, with a high impact value over a limited area, making them useful for cleaning or cutting processes on soft materials.

STRAIGHT JET NOZZLESWASHINGOTHER APPLICATIONS
FAA / FBAWashing of cloths, felts, partsRemoval of paints, rust, plating
GDWashing of fabric filters, felts, partsPaint and rust removal
GMA
PAPER WEB TRIMMERS
Washing felt, thread, partsPaper trimming
JAA / JBAWashing felts, fabric filters and partsRemoval of paints, rust and plating
GZS
AIR&STEAM FLAT FAN TIPS
Water removal from surfaces, water drying and detachment of tufts of fibers