Putting a New Spin on Things
A Look at Spray Balls
Dana Johnson, Birko Brewery and Produce Specialist
Brewing Techniques, November/December 1998
Clean-in-place (CIP) processes can literally be a lifesaver in the brewery. CIP is much safer than hand scrubbing because worker exposure to hazardous environments and chemicals is reduced. There is, however, more to CIP than simply turning on a pump and running some cleaning solution through a spray ball. This article takes a look at conventional stationary spray balls versus spinning type spray nozzles.
The spray ball is an integral component of the CIP process. The reason is quite simple. If the spray ball does not sufficiently deliver cleaning solution to the soiled surface, the equipment will still be dirty at the end of the cleaning cycle.
When evaluating the efficacy of the CIP process, time, temperature, chemical concentration and water hardness are the factors people generally take into consideration. For CIP, an additional (and equally important) factor is often over-looked.
Making an Impact
Impact per square inch is the amount of pressure that is applied to the surface during cleaning. Impact is sometimes referred to as “mechanical action.”1 Basically, the two things that determine impact in the CIP process are the pump and the spray ball. The pump must deliver enough volume and pressure to the spray ball so the spray ball can then (in turn) deliver enough pressure to the surface being cleaned. Volume of water is measured as gallons per minute (gpm). Pressure is measured in pounds per square inch (psi). Spray pattern distribution and spray angles determine impact.2
The pump used to CIP is normally the same one used to pump wort or beer. Typically, spray balls are stainless steel hollow spheres with holes that create a spray when pressurized with cleaning or sanitizing solution. If the pump and spray ball(s) are sized correctly for the equipment being cleaned, this set-up works just fine. There can be problems with stationary spray balls, however.
Stationary type spray balls sometimes do not provide sufficient impact in cleaning. (Admittedly, this can be the fault of the pump not providing enough pressure to the spray ball). When cleaning brew house equipment such as the mashtun, brew kettle or lautertun, holes in stationary type spray balls can become clogged with spent grain. If even one hole in the spray ball gets clogged, it can create a “dead spot” where the cleaning solution simply does not reach the surface. As a result, equipment does not come clean and the dead spot typically requires re-cleaning or hand scrubbing to finish the job.
Putting a New Spin on Things
Household automatic dishwashers are designed so that spray arms rotate to provide better coverage and cleaning. In the brewery, an option to ensure efficient cleaning is to replace stationary spray balls with rotating or spinning spray nozzles or heads. Spinning or rotating heads or nozzles are typically more effective than their stationary counterparts. A properly sized moving nozzle offers better coverage and the spinning action creates a scrubbing-like effect that cannot be achieved with a fixed spray.
There are many types of spinning spray heads currently on the market. Many of these units are not round in shape and are therefore not called spray balls. Instead they are called nozzles or heads. What follows are a few examples:
28500 Teflon ®* Fluid Driven Rotary Nozzle
Made of Dupont Teflon®, these units have a rotating collar when pressurized with cleaning solution. The spinning collar has holes drilled at various angles to give 360º coverage. It can replace existing stationary spray balls without any modifications and works well under normal brewery pumping conditions. The nozzle accommodates ¾”, 1” and 1½” tube sizes. Flow rates: 23 gallons per minute (gpm) for the ¾” tube, 33 gpm for the 1″ tube and 53 gpm for the 1½” tube. Although effective, it’s also expensive. Cost per nozzle is around $300 with tax and shipping.
Spraying Systems Co.
Phone: (630) 665-5000
(Various locations around the country-call for the location nearest you).
Mini-Whirling Nozzles Types 500.191.5E.00, 500.186.5E
For people on a tight budget, these units are made from precision molded PVDF. Designed to clean kegs, drums and small tanks with minimal amounts of cleaning solutions, the units will spin with a minimum of 5 psi. According to the catalogue, these units will tolerate a wide range of cleaners and solvents (even at high temperatures). With the low flow rates, however, these units are not designed for heavy-duty applications. However, they still give better coverage than static spray balls. Cost for the 500.191.5E.00 unit is about $56. The 500.186.5E unit runs about $166.
445 Kautz Rd.
St. Charles, IL 60174
Fax: (708) 777-2926
SVRU spray heads are made of 316 stainless steel and have rotating heads, which use a balanced-load sleeve bearing design. There are no ball bearings to wear out and the design allows the unit to operate in any position. Maintenance and cleaning is easy with the easy-on/easy-off bearing system. There are three models to chose from, each with different flow and reach properties. Coverage is 360º with a minimum start pressure of only 10-psi. SRVU units will require threading, however. Cost is around $200 each.
4120 A Horizon Ln.
San Luis Obispo, CA 93401
Fax: (805) 549-0131
Every brewery has their own way of doing things. When it comes to cleaning and sanitizing though, most prefer to get the job done as quickly, safely and effectively as possible. If the CIP application in your brewery is working and you are happy with it, don’t mess with it. If, however, the equipment still looks dirty at the end of the cleaning cycle, spinning spray balls, nozzles or heads may help. The increased cost of an efficient spray nozzle may more than pay for itself in reduced energy, chemical and labor costs.
Best of all, the beer may end up tasting better (and have a longer shelf life, to boot). Check with your chemical or equipment supplier and see what they recommend for your specific application.
- References Norman G. Marriott, Principles of Food Sanitation, Second Edition, 1989,Van Nostrand Reinhold, New York, page 92
- Spraying Systems Co., Industrial Spray Products Catalogue, Engineering Discussions, ©1994, page 6