Assessing HAZOP and Hygiene Design Requirements in Reducing Chemicals Increasing Assembly Safety & reducing Operating Costs
Spray Nozzle Engineering Ltd, a New Zealand spray dry nozzle innovation and export technology company, has set new world standards in nozzle and check valve technology designs. Their latest designs focus on improved hygiene levels, consumable operating cost reductions and powder quality improvements, thanks to some good old Kiwi industry experience.
The company has solved the problems experienced by several global trends in Spray Drying, with new designs that have shown to reduce site operating costs by up to 50% on nozzle wear parts, as well as eliminating the potential for costly wear part breakage and now, the ability to assemble without chemicals, a long term problem in the industry, where traditional conventions are becoming problematic.
Reducing the number of process contaminants in contact with speciality dairy powders, such as infant formula; by the introduction of a new generation of spray dry nozzles: Click&Dry™ Compact. A state-of-the-art nozzle technology that can be assembled without the aid of industrial lubricants or the use of chemical anti thread galling or seizing, a major step forward in product quality.
With spray driers now being specifically built to manufacturer higher yield products such as specialty powders, many quality and process audit professionals are looking at how they can assemble, operate and increase cleanability of nozzles, meet stringent audit, HACCP and HAZOP risk identifiers, but still operate a complex atomising nozzle without using additional chemicals, that in some cases, are in direct contact with the product, and are required in every spray dry nozzle assembly, especially with older traditional radially o-ring sealed nozzle bodies. To avoid damage to these exposed o-ring seals that are susceptible to dry assembly o-ring pinching and tearing, many plants have no choice but to introduce chemical lubricants on the nozzle surfaces. Spray nozzles new Click&Dry™ Axial compressive seal can be assembled safely without such additives and avoids the issue of o-ring pinch and tearing.
O-ring stretching and pinching as well as tearing on some radial o-ring seal nozzle bodies has now been recognised by both end-user dairy company safety groups and dryer OEM’s themselves, with many even writing this into their safety manuals to try and reduce the threat as much as they practically can, or to eliminate it all together by switching to a complete compressive axial body seal arrange, as used successfully on Click&Dry™ spray dry nozzles. So, it wasn’t until the introduction of compressive seal or axial seal technology as found in the Click&Dry™ nozzles, that for the first time high pressure spray dry nozzle could be assembled without the worry of radial extrusion, o-ring pinch or tear and inevitably leaking!
Another major issue on many modern spray dry nozzle and spray lance assemblies, has been the use of very tight assembly tolerances in plug and socket radial seal nozzle designs, a constant trade-off between requiring an assembly gap to get the cap inside the body without pinching or tearing the o-ring during the assembly, but also ensuring a seal of the o-ring on the inner wall of the cap. This problem is further accentuated if parts are worn through daily disassembly and cleaning. To overcome these radial sealing design tolerance issues, some designers sought to tightened inner assembly gap measurements, which in some cases can worsened the thread binding or galling problem; something Spray Nozzle Engineering has overcome with new axial seal body designs, that do not require clearance gaps, back up rings to prevent seal extrusion, or the use of Anti seize compounds. All Click&Dry™ nozzle caps and bodies come standard with a two year warranty, with extended warranties available from standard.
When tight design tolerances meet fine thread forms (found on some radial seal nozzle systems), and in conjunction with similar stainless grades used for both bodies and caps, (especially on mechanical assemblies that in normal circumstances would not be assembled or disassembled or handled when both hot and requiring cleaning after each run), then the propensity for thread binding and cross threading is increased; especially if impact damage is present. The inevitable increase in cross threading, binding or thread galling-damage ensues, meaning costly cutting, rewelding and testing of new nozzle bodies, that must be welded to the relevant pressure codes. To date one of the few ways to try and reduce the incidence of thread biding or galling was the application and use of anti-seize or anti thread galling chemical paste.
Originally designed for heavy duty industrial applications, many of these chemical compounds are not recommended or suited to direct food application contact. Furthermore, for many validation or audited production systems, the elimination of any or all foreign chemicals in direct contact with finished product, i.e. infant formula or inhaled powders is a pre-requisite, unless a stringent testing and approval regime has been undertaken, or that the product has been approved as “fit for human consumption”. Until the release of the Click&Dry™ compact nozzle series nozzles, that does not require chemical assembly lubricants and anti-seize compounds, there were no true “chemical lube free” spray dry nozzles on the market.
Spray dry nozzle operating and consumable cost reduction has been a major focus with Spray Nozzle Engineering’s latest hygiene series released for the start of the 2019 Drying season. As a result of many years of working with dairy companies in not only New Zealand, but also worldwide, it was found that a major issue for all dryer operators was the either the premature breakage of carbide wear parts during either the assembly-dis assembly or cleaning process. Also it was discovered that mis-alignment of internal wear parts in older nozzle cap designs, could lead to premature wear, especially in higher pressure or high abrasive concentrates sprayed at these higher pressures. The result was the introduction of a Kiwi first design, the Concentric Clasp Technology system (CCT), the world’s only spray dry nozzle that guarantees wear part alignment and concentricity; delivering performance and operating cost benefits.
Spray nozzles Concentric Clasp Technology (CCT) is now one of its biggest selling products, with almost 80% or their customers preferring it over its entry level parts retainer system. Basically it does what the name suggests, holds the wear parts i.e. the Swirl and Orifice Disc. Totally concentric or in linear alignment inside the nozzle cap body, particularly in relation to the outlet or where the spray plume exits the nozzle. Assisting laminar flow, it has shown to reduce wear of carbide consumable parts by up to 50% (a major cost saving for any dryer), and assists in reducing build on external nozzle caps; especially in long run applications where it is used in conjunction with Spray Nozzle Engineering’s extra low outer cap profile ‘Anti Bearding” nozzle cap system! All low bearding nozzle caps come with Spray Nozzles’ hygienic cap internal design, which has a smooth fluid path, free of o-ring grooves and threads, for increased hygiene and easier cleaning; allowing safer, longer runs.
Another major benefit of the CCT clasp, is that it acts as a unique extraction system, when used with the Easy-Out Clasp Tools, and comes with Spray Nozzles’ no parts breakage warranty when used in this way! Parts are extracted simply without the need to force them by Outdated Impact force tools, which only break or hair line fracture parts, leading to possible failure during operation, which is both costly and dangerous. Introduced as an option, CCT is now available as standard on all Click&Dry™ nozzles and can be ordered as a threaded insert for high pressure applications, and as PF or Push Fit version, that gives alignment with maximum cleanability.
All Click&Dry™ nozzles are available with the Drip-Pro check valve system. Designed as a self-cleaning assembly, with the largest free passages of any spray dry nozzle check valve on the market today, its chemical free assembly designs, and improved internals for easier cleaning, again meaning less chemicals are required in all aspects of their operation, have made it first choice with infant formula and commodity powder dryers globally, on all dryer types, who are looking to reduce scorched particles and post shut dripping into the fluid beds. The Drip-Pro can be easily inserted into the nozzles at any time and have a fully replaceable sealing face system. Various opening pressure springs are available to suit all applications.
The reduction in added chemicals also reduces the risk of over use and contamination, allows easier cleaning and hygiene of the entire system, but also assists in the auditing and safety function of plant operators, as there are simply two more chemicals taken out of the manufacturing process. Added to this, is the benefits of using an up to date nozzle system that is fit for purpose, more hygienic in its design, easier to assembly without error and delivers better performance and cost reduction to both operators and dryer OEM’s alike.
Click&Dry™ nozzles can be used on all spray dryer sizes and types, and are suitable for all powder types. Click&Dry™ nozzles are available as complete weld on system or as a conversion cap, that can be screwed straight into existing spray lances for an easy no weld upgrade.
All Click&Dry™ nozzles are designed to international, flow, pressure and droplet conventions and have been in use by the world’s largest companies for two decades.