It is a point of concern that many Spray Dry Nozzles in service today are not only old variants, possibly way past their safe service life, exceeding their maximum recommended pressure capability, or more commonly will typically utilise an old inferior body sealing method were a Clearance (Gap) Radial Seal type, Plug in Socket Seal Gland using a singular O-ring body seal providing the primary pressure seal that is simply not conforming to known modern sealing conventions and standards.
It is readily determined today that modern sealing standards and technology limit significantly the operational pressures that such singular radial O-ring seal glands using the necessary working clearances (gaps) required for damage free, daily assembly and disassembly. It is an increasing problem that these pressure limits are well below those pressures normally required in the modern Spray Drier.
This problem in the short term may be resolved with the use of Radial Seal Back-up rings, but it is well known to opertors with Back-up ring experience, that in using Back-up rings for increased pressure capacity and integrity, they have also discovered major service limitations, complications and cost drawbacks in Radial Seal systems that are required to be assembled and disassembled daily.
The new “Click & Dry” Spray dry nozzle is unique in the industry today by its use of two independent compressive axial o-ring seals one at the orifice disc and the other at the nozzle lance adapter.
Pressure spikes (Maximum system pressures) can regularly exceed typical working pressures (stated working pressures of systems). In some cases, not only the typical high working pressures, but the severity of pressure spikes in most systems demands the use of Backup rings to support typical nozzle radial seal o-rings to prevent run failures with the increased risk due to spikes.
Click & Dry sealing glands require no backup rings to satisfy most known potential pressure spike conditions.
Radial type seals require a radial gap between gland components for constant assembly and disassembly. It is this gap that is also subject to out of tolerance enlargement due to wear and damage.
These Radial seal glands were never really designed, nor are ideally suited to the rigours of daily assembly and disassembly and cleaning in the drier environment. An improvement was required.