Ingenieurbüro Merschbrock
Kochstr. 40
33397 Rietberg

Tel + 49 (0)5244/ 988156
Fax + 49 (0)5244/ 988157


UVC disinfection technology

The engineering office Merschbrock designs, develops and markets sterilization systems and monitoring equipment for these systems.

Main applications and products are

Basic technology for the sterilization is the application of short-wave high-energy UVC radiation, generated by mercury low-pressure lamps. The electromagnetic energy, contained in the UV radiation, is used to damage the DNA of microorganisms such as viruses, bacteria, yeasts and molds permanently. Standard systems and special solutions for the following markets are available:

  • Meat processing industry and meat manufacturing
  • Sausage factories
  • Delicatessen businesses
  • Bakeries
  • Dairies / cheese
  • Beverage industry
  • Producers of confectionery, jams
  • Fruit and vegetable processors (asparagus, onions, peppers, potatoes and much more)
  • Horticulture (plant breeders and propagators, seed farms, greenhouse operator, etc.)
  • Pet Food Industry

Further applications for UV disinfection technology are:

  • The medical technology, hospitals, doctors' offices, laboratories, nursing homes
  • The pharmaceutical industry
  • Agriculture (pig)
  • The metal processing industry (disinfection of cooling lubricants and other process water)

Typical applications are described below from the multitude of possible applications:

Surface Disinfection

In the field of surface disinfection, the engineering office Merschbrock has developed into a specialist. Whether it is disinfection of conveyor belts, meat cutting belts, packaging machines, cutting machines, filling systems or consumer goods, the engineering office offers special solutions for all categories. But the surface sterilization of unpackaged fruit and vegetables occupies an ever larger space.

Surface disinfection of fruit and vegetable products

Depending on the growing area, freshly harvested fruits and vegetables such as strawberries, raspberries, peppers, onions, asparagus, etc. are more or less contaminated with germs, which adhere to the surface of these products even after cleaning in a water bath. E.g. the addition of contaminated peppers to shasliks would lead to a reduction to their shelf life. A lately increasingly occurring problem is the contamination of frozen berries with Norovirus and hepatitis viruses. From time to time we read about recall campaigns of frozen berries or the outbreak of viral infections on cruise ships. Under the auspices of Prof. Uwe Truyen, The University of Leipzig has determined the required UVC dose necessary for the inactivation of viruses in frozen berries (Inaktivierung von Murinem Norovirus und Hepatitis-A-Virus). The engineering office Merschbrock has developed a disinfection tunnel to decontaminate about 1.5 tons of frozen fruits per hour.

Sterilizing of meat cutting belts


In the process of cutting pigs, cattle and poultry slow moving meat cutting belts are used often. To prevent a possible transmission of germs effectively (from the beginning of the conveyor belt to further work stations), a UV radiation unit is mounted under the cutting belt. During the return, the surface of the belt is sterilized by one to two orders of magnitude. For mounting, special devices are available.

disinfection of conveyor belts


In a fully automated poultry cutting plant a variety of conveyor belts is used, with which the decomposed chicken pieces come into direct contact
In the illustrated wing section 25 individual conveyors are in operation, each equipped with the belt conveyor disinfection module. The belt conveyor disinfection modules in this section are mounted both above as well as under the conveyor belts. Integrated control boards, operated by magnets, turn off the disinfection modules automatically when they are swiveled away from the working position for cleaning purposes.

disinfection of cups in a cream cheese filling machine


In a filling machine for cream cheese, a number of 4 cups is sterilized. Overall 8 UV lamps inactivate the germs inside the empty cup.

disinfection of cups in a pudding-filling system


In terms of risk of contamination, pudding is a very sensitive product, much more sensitive than, for example, yogurt.
The standard method for disinfection of pudding cup has been the use of H₂O₂ (peroxide). In the illustrated filling system the H₂O₂ decontamination was replaced by UVC disinfection. This is a complete new development by Merschbrock. In this system, the UVC intensity is monitored by special UVC-sensors permanently. In addition, the low-pressure radiators are cooled in order to achieve the highest possible yield of UVC.

sterilization of cups in a yogurt filling system


In a filling machine for yoghurt cups two rows on a length of about 1600 mm are continuously exposed to UV rays before the cups are filled and sealed with a cover film.

disinfection of E2 crates in a poultry slaughterhouse


In meat cutting companies the cutted meat is transported in standardized transport boxes (so-called E2 crates) for further processing or interim storage. After automatic washing the residual germs are killed in a UV tunnel.

sterilization of meat boxes in the cutting of cattle

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In a North German factory for cutting cattle, E2 crates are disinfected with their opening showing upwards.

sterilization of sausage calibers and cans in a deli company


For the production of delicatessen salads such as the German “Fleischsalat”, meat sausages in the gut, cans with cucumbers and similar products, those products have to be transported into the clean room. With the shown UV Tunnel, the surface of these products is sterilized in a continuous process

sterilization of packaging in a deli company

polybeutel tunnel_hilcona

In the production of salads precooked potato slices, wrapped in plastic bags under vacuum, are used. The surface of this bag is highly contaminated with germs by transport and storage. With the shown tunnels polybags and other packaging are disinfected before opening over the mixer.

For more details about the Tunnel seeHygiene report 2_2010 ➞

Disinfection of consumer goods

If commodities have to be brought into rooms, where an increased risk of infection consists, the disinfection of these items by UVC is a good alternative for disinfection with chemicals. In this case it does not matter whether the objects to be disinfected e.g. have to be moved in a car from A to B, or if the items pass through a sluice to the site.

Thermal sterile boxes for surface disinfection

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The illustrated thermal sterile box is designed exclusively for a customer of the engineering office Merschbrock.
Via the DC electrical system of a car, while driving from point A to point B, the equipment is sterilized in the cooled transport box, that come in a high-security area to use. Typical devices are ultrasound examination devices, photo cameras, video cameras, cell phones, etc.

Pass Tunnel for sterilization of utensils


If utensils have to be brought into a high-security area within a building, the use of UVC Pass tunnels may be useful. Reasonably, these locks could be installed in a partition wall permanently so that a bypass is not possible.
Via a moving carriage the utensils to be sterilized are brought into the actual UVC chamber, where they are sterilized after closing the UVC opaque glass doors. After disinfection they are taken through the door on the other side of the partition wall again.

disinfection cabinet for larger utensils

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The pictured disinfection cabinet is used for surface sterilization of large objects which don’t necessarily need to be passed through a sluice.

disinfection cabinet and/ or pass tunnel for smaller utensils

kleine_schleuse_1 kleine_schleuse_2 kleine_schleuse_3

It happens more often that even commodities of daily use such as beverage bottles, break bread cans, etc. must be sterilized, before they can be taken to the workplace or in the break room.
This disinfection cabinets can optionally be equipped with two doors and be permanently installed in a building wall, or with only one door to be operated as a tabletop unit. More locations can be laboratories for product developement or rooms for quasi sterile packaging.
Also in the fight against MRSA problem in the clinics, disinfection cabinets can be used.

sterilization of heat exchanger fins in overhead coolers


The large surface of the fins in overhead coolers are an ideal place for the settlement of biofilms. These biofilms in turn set free microorganisms, which are delivered via the air stream of the overhead coolers in the workspace. In addition, the biofilm degrades the heat transfer resistance and thus the efficiency of the cooler ceiling.
Regular removal of these biofilms with biocides and chemical cleaning is time consuming, labor intensive and thus expensive.
An elegant alternative is the installation of UVC lamps in the ceiling cooler or in the immediate vicinity of the heat exchanger fins.
The permanent irradiation -even with low UVC intensities- prevents the formation of biofilms.

More realized projects by the engineering firm Merschbrock for surface disinfection are the sterilization of:

  • transport pallets in a factory for baby food
  • Knives and sharpening steels in cutting and in slaughter lines
  • pneumatic tube cartridges for transportation of sperm in a semen collection center
  • ceilings, floors and walls in pigsties and animal transport vehicles
  • Various passage tunnel for equipment, food packaging and similar applications
  • conveyor systems in convenience factories
  • heat exchanger fins of refrigeration equipment

Air disinfection

In storage rooms and work rooms, in which food with large surfaces is stored open for a longer period, it makes sense to keep the microbial content in the air as low as possible. So no germs can deposit on the surface of these foods, that later continue to grow and lead to a shortening of the shelf life.
Typical applications are cold rooms, processing rooms (e.g. in delicatessen factories), slizer rooms in sausage factories, packaging departments for all types of food.
In these rooms the fresh air, which is sucked in from above, and the room air, which is circulated continuously through overhead coolers, are sterilized.

air disinfection in workrooms

In work areas of meat processing factories, the air can be sterilized through UV disinfection systems with its own fan, so that no mould can form on the sausages.

air disinfection in a slizer room by UV reactor chambers, which are attached to the suction side of overhead coolers


In working rooms, where unpacked food is stored, processed and packed for a longer period, such as in a slizer room, the number of germs in the air should be minimized. A very effective method to do this is to mount UV radiators on the suction side of the overhead evaporators. Depending on the air flow rate, a different number of UV lamps is mounted to these cases, which continuously sterilize the ambient air and the surface of the heat exchanger fins.

Installation of UV lamps in an insulated pipe for the fresh air supply


The air that is supplied to the working rooms from outside is more or less contaminated, depending on the environment of the factory. In order to don’t let this seed cargo enter the production rooms, you can install UV lamps in the air ducts and thus sterilize the outside air.

More realized air sterilization systems by the engineering firm Merschbrock are the sterilization of:

  • Air supply in pigsties (combating PRRS virus)
  • Sterilization of breathing air in boar transporting- trailers
  • Air disinfection in climatic chambers (pharmaceutical industry)
  • Filling in the dairy industry and beverage industry
  • Facilities for in the cultivation of orchids

Disinfection of liquids

For the disinfection of water from their own wells or the sterilization of "clean process water" there are pass through reactors available.

Stainless Steel Water Reactor EWR

Stainless steel case with UVC lamp for the sterilization of water. The pollution of the quartz tubes is permanently monitored by special electronics.

Flat-bed reactor


For the disinfection of process water the engineering firm Merschbrock has developed a flatbed reactor. The liquid to be disinfected and sterilized is delivered in a thin layer (1 to 3mm) above the bottom of a tray and is disinfected in the run by multiple UV lamps.

UCV disinfection in animal husbandry

In animal breeding, especially in the piggery, it is important to keep viruses and bacteria from the animals, as these can cause huge financial losses in unfavorable cases.

The PRRS virus (porkines recombinational and respiratory syndrome), which was first identified in 1987 in the US, attacks the sexual organs and the lungs of pigs. It is transmitted through the air and may overcome several kilometers, e.g. from one farm to another.

More dangerous germs are the influenza virus and all in animal known breeding pathogenic bacteria such as salmonella, mycoplasma and the multi resistant MRSA, just to name a few.

Air disinfection in piggeries

In the pig breeding establishments, producing sows and boars for the pig fattening, the engineering firm Merschbrock has already installed numerous UVC systems in the air supply channels of piggeries. It is important to calculate the correct UVC power regarding the lethal dose of the germs to be eliminated, so in all seasons a sufficient UVC dose in the supply air flow of the stables is available. Further applications for air sterilization are boar trailers.


Disinfection of fresh air in a farrowing pen with 16 UV lamps.
Subsequent installation in an aisle of an existing barn.


Disinfection of incoming air in a geothermal heat stable.
In the illustrated collection shaft the fresh air flows past the UVC emitters from the bottom upwards, after it previously passed numerous pipes, which are mounted under the stable and are cooled or preheated, depending on the season.

zuluft_stallneubau_1 zuluft_stallneubau_2

Disinfection of fresh air in a newly built barn with a dormer solely built for this purpose.
The Dust filter in the right picture on the left. To the right the UV lamp with aluminium foil in order to increase the radiation dose.


Boar trailer of an insemination centre.
Behind the door 6 UVC lamps can be seen, with which the breathing air for the animals guided into the interior is sterilized. The emergency generator on the drawbar provides the energy for the fan and the UV lamps.

Surface disinfection in animal husbandry

If you want to enter a piggery, e.g. as a veterinary, an employee of a scanning service, an artisan or a visitor, you must first get rid of your clothes, take a shower and put on other clothes, provided by the farmer. This is to prevent germs to be carried in to the barn from other farms or other sources.
Because germs can be found on the surface of tools, materials (e.g. neon tubes, feeding equipment), examination equipment, etc. so-called UVC locks are used more often, in which the equipment is exposed to UVC radiation for a certain period, to inactivate unwanted germs.

UVC disinfection tunnel at a semen collection centre

Mobile, rotating surface disinfection device for the disinfection of ceilings, walls and floors in a pigsty


Sterilization of the interior of pig transporter after cleaning

UVC Measurement

For many UVC disinfection systems it is essential, that all installed UVC lamps are actually in operation and that the age-related or pollution-related decrease of performance of the UVC emitters does not exceed a certain threshold.
Because reliability often cannot be verified by purely visual inspection, it is advisable to use special measurement technology.

UVC Line system for monitoring UVC systems

For this reason, the engineering firm Merschbrock has developed the UVC-Line System. With a DIN rail module, up to eight devices (which are usually the electronic control gear with which the UV lamps are operated) are monitored. On the one hand, the operating current of the electronic control gear, and on the other the elapsed operating hours, are monitored. If the pre-set limits are underrun or exceeded, a signal is output via a potential-free contact or a RS485 bus. Moreover, it is also possible to measure the radiation intensity via a UV-measuring diode and to evaluate the value (mW/ cm²) via the bus.

UVC-Logger for manual measurement of UVC radiation intensity and UVC dose

In addition to the UVC-Line module we have developed a handy measuring device, called the UVC-Logger, with which it is possible to measure the radiation intensity individually, save the values and transfer them to the PC via an USB-port.

With the operation category “dose” the device can be e.g. sent through a disinfection tunnel to check the actual UVC dose at the end of the line.

measuring device for detecting the radiation intensity and dose of UVC systems.

Prospect ➞

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