Spray Injectors: Critical but Often Overlooked Components
At the heart of any spray application is the spray nozzle. But equally important in a spray system is the spray injector (also known as a spray lance or quill) that delivers the liquid and/or gas to the spray nozzle.

Like spray nozzles, spray injecto rs must also meet exacting standards to ensure optimal performance and to prevent costly inefficiencies. Relatively simple operations can often use a standard injector. Applications like gas conditioning, chemical injection, secondary fuel injection, emergency quench, and lime slurry injection often require a custom solution. Here’s why:

• Spray injectors used in these applications typically require sophisticated designs. Integrating the injector into the available space can be complicated and a standard solution, available in pre-determined designs, may be too simplistic
• Special materials and coatings are required to withstand high-temperature, erosive and/or corrosive environments
• Insulated, water- or steam-jacketed injectors often prove to be more effective in high-temperature applications
• Extreme engineering and safety issues require compliance with ASME® codes such as B31.1, B31.3 and others
• Retractable and flexible designs are frequently needed to minimize or eliminate process interruption and/or maintenance downtime. In most applications, standard hydraulic or gas atomizing nozzles are used in conjunction with a custom injector to achieve the desired spray performance

If you have a sophisticated application, give some thought to the equipment upstream of your spray nozzles. You may find that an integrated solution – spray nozzles and injectors – can help improve spray performance.

A spray system that is not working optimally can very quickly cost your operation tens – even hundreds – of thousands of dollars annually. When nozzles become partially blocked, spraying efficiency is compromised and process and/or product quality typically deteriorate. Scrap, maintenance time and lost production can also quickly escalate.

Simple But Effective Ways to Prevent Clogging
Proactive maintenance is the best way to prevent clogging problems from occurring but even well maintained systems can experience problems from time to time. Most spray systems can be efficiently maintained in good operating condition by manually cleaning nozzles at regular intervals. But a word of caution – only use materials that are much softer than the nozzle orifice surface. It is very easy to damage the critical orifice shape and/or size and produce distorted spray patterns or excess flow. When nozzles become clogged and manual cleaning with the appropriate tools doesn’t solve the problem, try soaking the orifice in a non-corrosive cleaning chemical to soften or dissolve the clogging substance.

Most applications can benefit from adding strainers, which are an easy and economical way to minimize clogging. Strainers, including spray nozzles with built-in strainers, trap larger particles and prevent debris from entering the spray nozzle orifice or vane.

Popular and effective strainer types include:
Integral strainers can often be ordered as part of the nozzle itself and are available in a variety of mesh sizes and materials for standard and quick-connect spray nozzles.

T-strainers and simplex/duplex basket strainers are another option. Most allow a system to be quickly shut down for strainer basket cleaning or change-out. Some can be cleaned on the fly without shutting down the pipeline.