Overview of Vessel Spray Cleaning Methodolgy 

The first application of spray cleaning were made in the dairy industry in the mid 1950's.  The vessels were simple stainless steel tanks milk storage tanks iof horixontal cylindrical or rectangular design  or transport tankers, limited to farm bulk pick-up tankers initially.  Process vats were next in sequence, and then in the ealy 1960's the dairy silo-type tank, vertical, with all openings in a resricted alcove area.  Cleaning was by chemical action and spray devices were required only to provide coverage of (in most cases) the upper third of the product contact surfaces as cleaning of the remaining area was by solution rub-down on the tank sidewall areas and across the bottom to the outlet.  All storage tanks were fitted with agitators, some top mounted and with no seals, and some front mounted, requiring seals.  Upper openings into the vessel were limited to vents, observation windows and light fixtures, and occasionally top inlets for product.  Many of the tanks were bottom filled and emptied.

• Fixed ball-type spray devices were the early choice of most vendors, generally cleaning chemical supply companies, and the regulatory authorities required only that:
• The spray devices be fabricated to of the same material as the vessel, generally stainless steel, to the same standards as were applied to the vessels in whihc they were installed.
• The spray devices were required to be easily removeable for inspection, and all internal surfaces had to be fully visible.  Since the early applications were primarily to existing vessels for many years, the size, shape, and manway access criteria in existence for manual cleaning made this requirement easy to meet.
• The surface finish was required to be equal to that of the vessel product contact surface.
• The sprays were expected to be immersed in the product and were therefore required to drainable, a requirement generally met with a single 1/16" or 5/64" hole in the bottom of the ball-type spray.

Seiberling and Wish received a US Patent for a fixed ball-type spray device in 1956 and licensed Klenzade Products to market these sprays domestically and later internationally as Canadian and UK patenst followed. By 1960 it was generally accepted that a single spray with two balls on a horizontal arm would clean a tank of 5000 gallons in capacity fitted with a single verticall top mounted agitator and 80 Gpm would provide adequate coverage.  If the horizontal tank had two agitators, two 40 Gpm balls would be installed, centered in each half of the tank's length.  Twenty years later, 90% of all spray cleaning accomplished by the pioneering spray vendor was done with one 80 Gpm double ball spray, one 80 Gpm single ball, or tow 40 Gpm single balls. 

Electrol Specialties Company began manufacturing sprays for the non-dairy segment of the food industry in about 1980, for equipment that required custom designed (drilled) fixed sprays. These sprays were not standard, with respect to flow, or drilling patterns, or even configuration as the equipment to be cleaned required many different arrangements.  A smaller 2-1/2" size proved to be quite versatile and various configurations of tubes with 1-1/2" bubbles fullfiled most other needs.  These sprays initially developed for cleaning equipment used in dry granualar processes   Directional drilling was required to assure contact with hard to reach areas and drilling patterns were controlled to minimize the flow rate.  Seuqencing solution through a multiplicity of sprays in different arreas of the process was also beneficial.  During the mid-1980's and early 1990's as the pharmaceutical industry began adopting CIP  technology.  The pharmaceutical tank was not a problem that could be solved with "standard sprays" and appeard to be a candidate for the application of the custom design methodology.

Fixed Ball-Type Sprays

The traditional ball spray has been in use for more than 40 years as the most commonly applied and only 3-A compliant spray device for dairy, food, brewing and wine production processes.  It has been used in the pharmaceutical and biotech industries for more than 20 years, in processes handling liquid and dry granular materials. The standard ESB-# consists of a flattened 2-1/2" spherical spray head welded to a slip joint and affixed to a 1-1/2" diameter straight supply tube 18" in length. The spray and supply tube are inserted in a 3" clamp type nozzle. Standard drillings are for 20, 30 and 40 Gpm at 25 Psi in a 120 degree upwards conical pattern.  

Options include:

• Supply tubes with elbows (as illustrated) 
• Spray heads welded to supply tubes (for straight tubes only, to meet inspectability criteria)
• Bottom or full coverage to maximum delivery of 80 Gpm
• Smaller 1-7/8" heads for installation in 2" clamp nozzles, drilled 10, 15 and 20 Gpm at 35 Psi 

Tube Sprays

These unique sprays consist of a length of 1-1/2" tube containing die-formed, radiused pullouts to which 1-1/2" half-sphere custom drilled spray heads are welded, being located as required to spray in multiple directions.  Widely used configurations include the Bent ube Spray fitted with a 3" clamp installation fitting, and the Straight Tube Spray which is fitted with a 2-1/2" installation fitting.  Both types of sprays are custom fabricated to order.  Individual spray heads are normally drilled in the range of 5-10 Gpm and may be "Directionally Drilled" to effectively apply a  minimum amount of flush, wash and rinse solution to a specific area. The normal delivery per Spray Tube ranges from 25-40 Gpm.

Options include:

• Tube may originate at a pullout on the bottom of a 2-1/2" ball type spray
• Half-sphere spray heads may be added to supply tubes for ball-type sprays to handle specific coverage problems

 Bubble Sprays

These sprays are fabricated by directionally drilling the same half-sphere described above, and then welding it to either a elbow or straight supply tube with a 1-1/2" clamp installation fitting.  Field application is by insertion through a special 1-1/2" clamp adapter welded into the wall of the equipment to be cleaned. Bubble sprays are used most widely used to apply CIP flush, wash and rinse solutions to a diverse assortment of dry granular material processing equipment, and the associated ductwork, but may be applied in a similar manner for some liquids processing systems.  Spray flow rates are generally in the range of 5-10 Gpm at 25 Psi, via custom drilled patterns which require the elbow supply tube for proper positioning. 

• Material:  Type 304 or 316 stainless steel, or other, including hastelloy
• Spray Orifices: Generally drilled 1/16" or 5/64", to meet flow and coverage requirements. All orifices are chamfered inside and outside
• Physical Characteristics:  All sprays are designed to be easily removable for field removal of non-soluble debris, and are otherwise self-cleaning, self-draining, and polished to a #4 finish or better, as required.  Electropolishing is an available option. 

Computer Assisted Drilling Pattern Design

 This is going to work just fine

Spray Position Indexing

Removeable spray devices must always be pla ced in the vessel nozzle in the correct posiiton and  therefor require some means of identicification.  These sprays are fabricated by directionally drilling the same half-sphere described above, and then welding it to either a elbow or straight supply tube with a 1-1/2" clamp installation fitting.  Field application is by insertion through a special 1-1/2" clamp adapter welded into the wall of the equipment to be cleaned. Bubble sprays are used most widely used to apply CIP flush, wash and rinse solutions to a diverse assortment of dry granular material processing equipment, and the associated ductwork, but may be applied in a similar manner for some liquids processing systems.  Spray flow rates are generally in the range of 5-10 Gpm at 25 Psi, via custom drilled patterns which require the elbow supply tube for proper positioning.