Conclusions
Water can, it seems, be “flung” in a variety of different ways. Indeed spray nozzle manufacturers will boast catalogues with literally tens of thousands of different nozzles. Most of these will be variations on the basic designs discussed above but nonetheless getting the correct nozzle to produce the spray with the optimum characteristics for your process is not a simple task.
We appreciate that our Guide to Spray properties is unlikely to enable the reader to make a completely informed decision on exactly which nozzle will produce the precise spray required for any given process. It will however, enable the start of a meaningful conversation with a specialist manufacturer.
The list below of what information is helpful to a nozzle supplier to enable them to specify the best product for you quickly and without hassle may also be useful. Of course, if you only have some of this information, we can still help so give us a call. Read on or watch our video below.
What information is helpful when specifying nozzles?
Application
Firstly, the most important piece of information we require is the application. At SNP, we have decades of experience dealing with various spray applications. If the application is specified at the start, our knowledgeable experts can offer immediate and useful advice from past experiences dealing with similar applications.
Fluid supply
- The maximum pressure that the pump can maintain
- The flow rate that the pump can maintain
- The pump curve (the relationship between pressure and flow rate)
- The pipe factors between the pump and the nozzle (the likely frictional and gravitational pressure losses)
- What the nozzle can see (the range of pressures and flow rates)
- The flow rate (variations and tolerances – applications such as coating will have a precise flow rate. But for other application such as dust control, the flow rate will be less refined)
Targeting
- How are we going to accurately direct the spray? Will there be any leeway there?
- Where does the fluid need to go?
- Do you need an even or uneven distribution of fluid? (This heavily relies on the application).
If you provide the answers to those questions, this will equip our team with all of the correct information to correctly position the nozzle and ensure the spray hits the target.
Air
- Are air atomisers an option?
- Is the air on site?
- If not, is it possible to get air on site?
- Is it possible to use air in this application? (Some applications do not require air and this will widen our scope of nozzle selection and thus, offer more options for you)
Environmental conditions
- The temperature of which the liquid is going to be sprayed
- What the nozzle is going to be spraying into, (this will significantly affect the material selection)
- If it’s going into a gas flow, (what is the gas flow and will it be moving? Is there going to be any variation?)
- If there’s windy conditions, (this can affect the direction of the spray)
- Corrosive factors – is the environment likely to be corrosive?
Fluid properties
All data sheets are calibrated for water and if it’s just water being sprayed, this isn’t an issue.
- But if a different liquid is being sprayed with a different viscosity and specific gravity and surface tension, we will need to know what the fluid properties are to ensure the appropriate adjustments are made
- The other fluid property that is important to understand is particulate content. How well filtered is the fluid going to be? If it's pure, clean and very well filtered water, this gives us lots of options. But if there is going to be contaminants in there that can clog up the nozzle, our options become limited because we'll need to look at clog resistant nozzles.
Good nozzle manufacturers will have software to enable quick droplet size, impact and reach calculations to be performed for their range of products. So at the very least this article should enable the reader at least to appreciate what information a vendor will need to make the necessary calculations. It should also arm the reader with enough information to detect those that have, how shall we say, a “less than perfect” understanding of their product!