AIR, WATER, AND SURFACE

Purification Experts Since 1951

Why Use UV for Disinfection?

The use of ultraviolet germicidal radiation to eliminate the growth of micro-organisms was pioneered by Fuller Ultraviolet Corporation, and its wide applications have placed us in an authoritative position to meet the demands of our customers. Ultraviolet germicidal energy is radiation produced by low pressure mercury lamps. The lamps are made of special glass which allows the passage of light rays emanating 253.7 nanometers. This particular radiation has the ability to kill all micro-organisms it comes in contact with. The destruction is accomplished quickly and effectively. The UV rays strike the various micro-organisms, whether they are bacteria, virus, yeast, mold or algae, and they break through the outer membrane. The radiation reaches the heart of the organisms (commonly known as the DNA) where it causes abrupt modifications. The modified DNA transmits incorrect codes or messages, and this impairment actually bring about the destruction of micro-organisms. UV disinfection is a critical and reliable way of protecting your product.

Why Fuller Ultraviolet?

Experience

Fuller Ultraviolet started in a shop at 75th and Yates in South Chicago back in 1951. Since then, they have manufactured thousands UV disinfection devices for a wide variety of industries. As the years move forward, Fuller moves forward in designing efficient, cost effective ultraviolet filtration equipment tailored to your industries current and future needs.

Flexibility

Fuller is committed to providing the most effective means to keeping counts and condensation down in your tank. This is done by a successful line of standard equipment, that can be modified to fit any unique application.

Positive Directions

Fuller is continuously moving forward and finding ways to increase your products quality while keeping installation and maintenance costs down for your Sterile Conditioners and Air Vents. Safety, accessibility, durability, are all key factors in the design.

Satisfaction

By keeping counts down in your liquid sugar storage tank, Fuller is decreasing your losses, while increasing your quality and customer satisfaction. At the end of the day, that's what keeps us motivated to present the best possible UV disinfection products.

The World of Ultraviolet Light

Germicidal light has powerful, built-in inherent determinates that, under the right design conditions, provide a means for lethal destruction of microbial organisms whether they be in air, liquids or on exposed surfaces. The ultraviolet rays emitted from germicidal tubes radiate through its chosen medium and destroy micro-organisms in their path. This propensity for destruction can be likened to the photographic effects of light in that an exposure is the product of intensity and time. In theory, such an exposure to germicidal ultraviolet rays may be obtained through a long time exposure with low UV intensities, or through a short time exposure with very high UV intensities. In practical applications, the design of a UV system is usually determined by the requirements of the job to be done with a range of up to one minute for air disinfection to a fraction of a second for liquid disinfection. Design considerations must be adjusted to secure adequate exposure times.

Germicidal Applications

Sugar
Sugar Refining Granulated Sugar Syrup
Instruments
Doctor's Instruments Dentist's Instruments Barber Shop Instruments
Meats
Meat Coolers Packaged Meat Meat Processing
Biologicals
Vaccines Serums Antibiotics Toxoids Ointments
Other
Bottled Drinks Beer Spices Pharmeceutical Pickles
Industrial Liquids Spoilage Protection Packaging Cheese Odor Protection
Plastic Films Food Processing Juices Food Packaging Bread
Fruits Poultry Hatcheries Hospital Operating Vegetables Bottle Caps
Rooms Vinegar Cleanrooms Oils Cosmetic Industries
Waste Water Treatment Dyes Airduct Systems Water Disenfection Shoes
Potable Water Textiles Animal Kennels Ink Curing Toilet Seats
Bottling Wine Fish Hatcheries Storage Cabinets Syrup
Nuts Glasses Toothbrushes Hot Tubs Swimming Pools

What Is This Thing Called Ultraviolet?

There are basically four principal wavelengths in the ultraviolet spectrum that lend themselves to specific applications. These principal wavelengths are described below:

UPhotochemical:

which is commonly called UVA (or black light). UVA light is in the longer wavelength region of the UV spectrum and typically has a peak emission of about 365 nanometers. The principal users of UVA have centered on inspection of fluorescent surfaces, body tanning and treatment of skin diseases like psoriasis.

Erythemal:

which is commonly called UVB. UVB light is found in the middle wavelength region of the UV spectrum and generally has a peak response at 312 nanometers. The principal use of UVB lamps has been medically for the treatment of skin diseases. There is some commercial use in the aging/degradation cycles for products.

Bactericidal:

which is commonly called UVC. UVC light is found in the shorter wavelength region of the UV spectrum and generally has a peak response at 253.7 nanometers. Its primary use is for the destruction of bacteria and other micro-organisms in air, liquid or on surfaces.

Ozone:

ozone is a gaseous allotrope of oxygen and is generated photochemically through ultraviolet lamps. There are other ways to generate ozone such as corona discharge; however, for our purposes, we will talk about photochemical produced ozone. It is produced as a gas at 185 nanometers in the UV spectrum. Its principal use has been as an oxidizing agent and as an effective sterilant.

The Mysterious Invisible Universe Called Microbiology

Most everyone finds it hard to comprehend the diminutiveness of the microbiological world. Telling someone there are lurking, unseen tiny monsters ready to do harm sometimes seems incredulous. Yet, “out of sight, out of mind” is no excuse for tolerance of bacterical and other microbial contamination. So, let's explore this mysterious imperceptible abode of microbes.

Microbiology is the world of unseen life; it's a world of teeming microbial life comprising bacteria, mold spores, yeast and viruses. Each of these tiny live organisms is a microbe, yet each is very different from one another. They can be located and identified by sophisticated microscopes, and upon measurement we find these microbes are very, very small, generally about 1/25,000th of an inch. They reproduce at phenomenal rates. For instance, if bacteria reproduction was left alone, we could be inundated. Assuming a generation period of one bacterium of thirty minutes (these microbes reproduce by one cell dividing every 20 to 30 minutes) you could expect a bacterial mass weighing 10,000 tons in 36 hours!

Fortunately, environmental inhibitions and other factors control microbial epidemic activity, and we are not faced with this uncontrolled growth activity. Nevertheless, some of these little “critters” play a very destructive role in contaminating air, liquids and product surfaces. Means must be provided to control this contamination, and ultraviolet germicidal lamps provide the tools for control.

UVC Penetration Capabilities

Penetrating, permeating, entering, perforating; no matter the description, it is an important function, and one that deserves careful consideration in designing UVC systems. UVC rays do not have great penetration ability on most substances. Obviously, in the case of air, it has a very effective killing range. Penetration is ineffective on such substances as meat, cloth, food, glass and other such “solid” materials. Consequently, air and surface irradiation are principal functions of UVC light.

On the other hand, the bactericidal treatment of a liquid is very effective depending, of course, on the conditions imposed by the liquid, the methods of handling it and the effective transmission of the UVC germicidal energy into the liquid. In the case of disinfection techniques of granular materials and powdered solids, the theory is practically the same as for high absorptive liquids. Actively stirring and agitating the surface of such materials is necessary to ensure an effective depth of agitation. Equipment must be capably designed and operated to provide for the minimum UVC germicidal transmission. Ozone, as a gas, has the ability to reach those hard to expose nooks and crannies. It is an important alternative.

Skin and Eye Protection

Overexposure to UVC rays can cause a painful and irritating condition on skin surfaces and eyes of individuals. The exposure time to cause such a condition varies with the sensitivity of each individual and also the length of exposure and intensity of the UVC source. The condition is temporary, and there are no known harmful physiological effects from the UVC rays except reddening of the skin and irritation of the eyes.

The condition is transitory and usually disappears within a day or two. Plant life may also be damaged by direct or reflected exposure to UVC rays. Transient dyes and colors may fade from prolonged exposure.The effects of overexposure to UVC must be dealt with in initial design considerations. Safety features should be incorporated, lessening or eliminating the hazards of UV overexposure. Personal protection can be achieved through the use of goggles, shields, gowns and other protective measures.

The Source of Ultraviolet Tubes

Generally, there are three types of ultraviolet germicidal tubes; namely, the hot cathode germicidal tube, the cold cathode germicidal tube and the slim line germicidal tube. They each have their salient points, and selection for a particular design must take into consideration the cognizant factors such as cost, tube life, intensity, temperature factors, environmental conditions, tube size and a host of other design elements.

Hot Cathode Germicidal Tube

Hot cathode tubes have the same electrical characteristics of a standard preheat type fluorescent tube. They operate on typical preheat (starter type) circuits such as quick start or trigger start. Tungsten filament electrodes located at the ends of the tube are coated with emission material and these electrodes govern tube life.

Tube life is somewhat nebulous because of certain factors. The number of “on and off” cycles play a significant role in tube life. In addition, the tube burning cycle is affected dramatically if operated in cold ambient temperatures such as cooling rooms, refrigerators, etc. Hot cathode lamps are frequently hard to start at low temperatures.

Cold Cathode Germicidal Tubes

Cold cathode lamps do not have tungsten filaments for electrodes. Instead, they are fitted with a firm solid cylindrical electrode at each end of the lamp. No starters are required since the lamp is started by means of high voltage input. Interestingly enough, the cold cathode tube electrodes rarely wear out. Thus, tube life is governed by the UVC transmission capability of the tube glass. This type tube works excellently in cold atmospheres, and the high voltage starting features virtually assure instant starting even in freezing conditions.

Slim Line Germicidal Tube

Slim line germicidal tubes have similar electrical characteristics to slim line fluorescent lamps. Like the cold cathode tube, it does not require a starter and uses high voltage for starting. An interesting feature of this lamp is that it starts cold by the high voltage shock but operates with the electrodes hot. Tube life is governed by the life of the electrodes. The most popular of the slim line germicidal tubes is the G36T6 series. It's possible to operate the G36T6 at four different current levels of 120, 200, 300 or 420 milliamperes. This allows four different UVC outputs.

UVC Tube Life

A surprising phenomena occurs when a UVC lamp is lit. The phenomena is that you simply do not know by visual inspection if the lamp is operating satisfactorily. A number of important factors are involved here: First, UVC energy is invisible to the naked eye. Even though a tube may appear to be operating satisfactorily because it maintains a blue visible glow, the ultraviolet emission may be greatly decreased. The blue visible glow is actually part of the visible spectrum. Another feature of the tube is that after a significant amount of operating time, the glass can solarize. This solarization prevents the ultraviolet from being emitted through the glass tube. UVC tube life has a normal depreciation cycle. During the first 100 hours of operation, the depreciation is rapid, and as a result, tubes are given an initial 100 hour rating. Depending on the type of tube, rated life can vary from 5000 hours to 17,500 hours. Although the UVC tube has an effective operating life, it is of utmost importance that lamp maintenance be monitored with a UVC meter. These types of meters are readily available for direct measurement or with remote sensing and monitoring capabilities.

Practical Uses of UVC Devices

Now, we finally get to the point where UVC can (and should) be used. Obviously, not all microbial entities are pathogenic. There are many applications of ultraviolet germicidal tubes, and these applications may range from simple fixtures that direct UVC rays to a source of contamination to the more complicated UVC designs for specific applications. The old adage which says “The Sky's The Limit” is most apropos. In addition to the listed product possibilities, UVC is very applicable to other possibilities. One area is animal protection. Animals, like people, are quite susceptible to diseases transmitted by airborne microbial contamination. UVC has been very successful in boarding rooms, laying houses, incubators, hatcheries, stables, pens, veterinaries and other such areas.

Another area in which UVC is very appropriate is in personal protection. UVC disinfection of air by means of room irradiation or air duct irradiation can protect personnel from possible infection due to airborne microbial infiltration. This type of protection is applicable in numerous areas such as hospitals, clinics, medical and dental offices, clean rooms and just about any area where people congregate. There are numerous conditions which require or need non-chlorinated water for processing. Some examples can include dairies, breweries, bottling plants and pharmaceutical houses. There are many residential, commercial and industrial applications that need water (or other liquids) to be free of microbial contamination. The use of ultraviolet germicidal liquid processors is most necessary.

Ozone

Ozone, you've heard it almost daily in the weather forecasts. The average person thinks of it as a nasty substance, and that it is a major pollutant in our environmental involvement. As usual, erroneous media reporting has cascaded the term "ozone" into a most unpleasant word. So what is the real truth about this most remarkable substance. What is it? What isn't it? How does it work? Does it work? What does it do? Lets take a brief look at ozone. Ozone is a gaseous allotrope of oxygen, and it is known as a very strong oxidizing agent in addition to being an extremely effective sterilant.

It has been commonly used for many years as a water sterilant. Many major cities use ozone for this purpose, amongst which include Moscow, Paris, Nice and, most recently, Los Angeles. In fact, L.A. has the largest ozone generating plant in the world. Recently, ozone has been found to be extremely effective against microbial contamination of other materials. Ozone has a unique advantage in that it is a gas and, as such, has the capability of reaching all those “nooks and crannies” to perform its microbial destruction in a most efficient manner. Ozone is efficiently generated by ultraviolet radiation having wavelengths below 200 nanometers and, most specifically, at 185 nanometers.

Ozone is excited by other UV radiation and is destroyed by ultraviolet emissions at 253.7 nanometers. It is noteworthy that organic molecules are also excited by ultraviolet energy across the spectrum. The most efficient design of UVC equipment uses a combination of wavelengths to achieve a balance between ozone generation, decomposition and molecular excitation. Ozone is a most useful tool by itself, and when used in conjunction with UVC, the overall decontamination process works synergistically.

Germicidal Lamps

Fuller germicidal lamps in standard designs use Vycor quartz and Corning 9823 glass or equivalent. On special requests, lamps can be engineered to use ozone free quartz, Suprasil or other special glasses. Germicidal lamps having quartz, Vycor 7912 or Suprasil glass tubes emit various amounts of ozone. As a matter of interest, lamp bases can be furnished in standard plastic or ozone resistant ceramic on cold cathode and slim line lamps.

Germicidal Ultraviolet and Its Influence on Infection

Infection, a dreaded word, is actually the spread of disease-producing organisms called pathogens. Pathogens live nearly anywhere in our everyday environment; air, water, surfaces and within the body in body fluids. Obviously, there are certain locations and certain occupations that have a higher risk, and this is usually found in the medical and dental environment. However, wherever people congregate, the chance of infectious transmission is highly significant.

The use of germicidal devices to reduce or eliminate the threat of microbial transmission is an efficient, effective environmental method, whether the transmission is via airborne, waterborne or on surfaces. Pathogens must enter the body for a person to become infected. This transmission enters the body most commonly through cuts or scrapes in the skin or mucous membranes and also by direct transmission to mouth, eyes, nose or aspiration into the lungs. Microbial contamination of food, water or other liquids also provides another causative pathway for infection. Fuller UV germicidal devices are designed to meet the threat of just about any type of microbial contamination in almost any environment. We suggest contacting a Fuller trained engineer to discuss your particular problem.