Nyír-Clave Kft

Nyír-Clave Kft

`Nyír-clave Kft. had been established in 1998 with the aim to provide a modern alternative of sterilizing contaminated health waste to incineration, which also could be expanded to veterinary hygenics. Previously for sterilization of contaminated health waste only incineration was the solution. Realizing, that although the techonolgy was efficient, it did not meet all requirments or rather that the installed smoke-filters and catalysts could not absorb alltoxic materials, like dioxin.`

Company details

4400 Nyíregyháza Szabadság tér 5/A II.15 , Hungary

Locations Served

Business Type:
Industry Type:
Waste and Recycling - Waste Management
Market Focus:
Internationally (various countries)
Year Founded:

 Nyír-clave Kft. had been established with the aim to provide a modern alternative of sterilizing contaminated health waste to incineration, which also could be expanded to veterinary hygenics.

Previously for the sterilization of contaminated waste only incineration was the solution. Realizing, that although the technology was efficient, it did not meet all the requirments, or rather that the installed smoke-filters and catalysts could not absorb all toxic materials, like dioxin. The discharging of toxic materials by incineration quickened the development and production of the so-called alternative equipment for sterilization of contaminated waste. Various types had been developed, but among all the most reliable and profitable is the technology of sterilizing with steam.

Greatest advantage of sterilizing with steam is that it may be installed anywhere, it does not discharge toxic materials and does not pollute environment.The sterilized waste may be treated as public waste or may be used for further recycling, like to produce bio-gas. One of the most successful equipment developed for sterilizing with steam is the Clave family, produced and distributed by our goodselves. In three capacities – 300, 1000 and 2000 liters. The Clave system differs from other steam sterilizing equipments, because the contaminated waste is first crushed into 2x2 cm cubes and after this the crushed waste is sterilized with 138 Celsius steam for 10 minutes at 3,8 bar pressure. The volume of the waste is reduced to 1/5th of original size and with compression may be further reduced.

After the production of the equipment in Hungary, for more safer and profitable operations we carried-out various modifications, on basis which we have been granted the neccessary technological certificates. After the equipment had been tested for animal hygene and is suitable for sterilizing of toxic animal waste, which could promote the realization of the EU resolution to abolish carcass wells.

The producers have ISO and TÜV certificates, which allows expansion for further export.

Definition of problem

The toxic health waste is a mass of contaminated waste which may contain syringes, needles, paper, plastics, glass or textiles. The anatomical waste should be treated seperatley by burning or incineration. Health waste resulting from nursing activity should be handled specificaly. The collection must be carried-out in separate containers, the contents must be neutralized safely on the hospital premises or must be sent to neutralizing plant outside the hospital.

Our solution
Before transporting the waste to public containers, the waste must be sterilized and the syringes destroyed. The essence of our solution is that the contaminated waste is sterilized in our Clave equipment. The contaminated waste is lifted to the upper part of the autoclave into a very hard and resistant grinding machine. The waste including the unwanted parts are crushed and discharged into the lower part of the autoclave. Then adding steam and increasing pressure (3,8 bars) the temperature is increased to 138 C. The operation is fully automatic and the cycle lasts for 40 – 60 minutes.( Clave 1000). The final result is a crushed mass ( sterilization safety=10), which now may be treated as public waste. The volume decreases by 80% of the original waste volume. This is why we say that our method is secure and economic.

The equipment may be used safely, special trained personnel are not required to learn operation one day is enough. All in all the operation is fully automatic and is equipped with such safety systems, that eliminates all manual operation, like the autoclave maybe openned only if the temperature and pressure is normal, or the cycle can not be started untill proper closing of lid., and the waste can only be discharged after last phase of sterilizing cycle is over. The equipment does not require maintenance, apart from usuall lubricating and the cleaning of grinding claws when neccessary.

Technology of grinding
The main part of the system is the grinding unit. The experts dealing with contaminated waste are quite aware, that one of the most difficult problem is the grinding of unwanted articles, like screw-drivers or similar articles which are capable of ruining the grinding mechanism. Also is known the problem of jammed machine due to melted plastic. The mechanism of grinding claws, which has revers rotatng , eliminates these problems. Every two minutes the rotation changes. The parts of the grinding machine are made of the hardest metal presently known.

The above detailed figures of pressure and temperature contain the neccessary data of achievment. The exact data are an optimum result where time and temperature factors are the most important parameters. By increasing pressure and temperature, the time period my decrease.

The basic differences between 'Clave 300, Clave 1000 and Clave 2000' : the bigest difference is the capacity of the equipment and their height. To feed 'Clave 1000 and Clave 2000' a crane is needed or a two floor building.

The operational mechanism of Clave system

  1. step: after opening the lid of the upper part of the chamber feeding is done.
  2. step: after the lid of the upper part is closed grinding begins. The grinding which changes rotation direction periodically, is capable of grinding the very hard obsticles also, like glass, surgical stainless steel instruments, even if these are unwanted materials, the melted plastic will not cause any type of jamming. The paddle-like device in the upper chamber will provide the continuous feeding of the grinder. The process may be followed through a glass window in the upper lid.
  3. step: heating is done with steam when the temperature rises to 138 C. degree and the pressure reaches 3.8 bars. The temperature is controlled and monitored by a thermometer placed in the center of the lower chamber. The temperature and pressure is the same in each chamber.
  4. step: sterilization is reached by maintaning 138 C degree/3.8 bars for a period of ten minutes. The mathematical cominbation of these various factors provide the possibility to decrease the contaminated level to SAL=10 value. The sterilizing condition will exist till the door of the lower chamber is open.
  5. step: cooling to 80 C degree is reached – without watering the waste – by spraying cold water on the walls of the inner chamber. Simultaniously the pressure will decrease also.
  6. step: The next phase is the draining of cooling and condensed water
  7. step: The idle phase makes it possible before opening the hatch to condense the remaining water in the chamber.
  8. step: The openning of the container is secured by an automatic closeing device, which allows the openning of the container only when all phases have been completed. After this the unloading of the grinded and sterilized waste may be discharged.


With the sterilzation of contaminated waste the obligated treatment process has come to an end, but before this two basic regulations have to be fulfilled.

  1. The collection of selected waste and their storeing must be organized on the spot where the hospital waste is originated from They have to provide the neccessary collection facilities, which may be, bags, water-proof cartons or plastic bodellas, depending on the type and volume of waste .Only such storage bins may be used, which have the correct marks and neccessary certificates. These are strictley regulated by rule of law and directives.
  2. If the contaminated hospital waste is not sterilized on the spot (hospital territory), then the transportation of the waste must be organized also, so that the waste is sterilized within 48 hours, otherwise it has to be stored in cold storage. The waste may be transported only by special trucks having ADR cerificates.The task and responsibility concerning transport are regulated by rules of law and directives. Not only do the means of transport have strict certificates, but the personnel in question must also have special licences.
  3. The collection, transportation and sterilization of hospital contaminated waste may be treated by three seperate companies specialized in their profile, but it also may be done by one company. If the sterilization is not being effected on the spot it is reasonable to use a company which is dealing with transport and sterilization, keeping in mind the 48 hour time limit.

Our team is ready for 24 hours operation for servicing of equipment for sterilizing contaminated waste.

Our professional team is also ready upon request, according to demand ( temporary or permanent) to provide maintenance for any type of our equipment. Upon request we can also provide continuous development of modernization of our existing constructions.

At present we can provide service and contineous development for electric, pneumatic, hydrolic and various mechanical devices.