Technical field

The invention relates to a container hygieniser for biodegradable municipal wastes and a method of hygienlsation thereof. The invention falls within the field of waste processing.

Existing state of art

Biodegradable municipal wastes also include catering bio-waste originating in the households and catering establishments. These are the residues from the cleaning of fruits and. vegetables, residues of cooked meals, etc. From the quantitative point of vrew^ the catering and restaurant bio-waste is the most important component of mixed municipal waste. Depending on the time of occurrence, it constitutes a 30 to 45-percent weight share. This component of separated collection must be unconditionally sorted out already at the source of its origin, so as to avoid excess contamination by with foreign substances. This waste needs urgent processing. It is a very dense material and it has to be mixed with bulk agents (such as straw or wood chips) when composting to improve air penetration. Frequent turning is necessary, especially during the early stages of composting. As rotting waste, it has high demands on air and quickly passes into the anaerobic phase of fermentation. Therefore, it is also used in anaerobic digestion. It occurs throughout the Whole year. At composting and blogas production from catering wastes of animal origin or mixtures of plant and animal materials, it is necessary to comply with the rules designated by the Commission Regulation (EC) No 1774/2002.

The hygienlsation of bio-waste la a process in which pathogenic microorganisms are eliminated or significantly reduced by the effect of high temperature and time and hence also the health risks associated with the application of products made from this bio-waste.

Commission Regulation (EC) No 1774/2002 on animal by-products started to apply in the Slovak Republic from our accession to the EU in May 2004. This regulation establishes health regulations concerning animal byproducts not intended for human consumption. The regulation lays down the rules for the handling these products, tightens the feed ban and furthermore brings a higher degree of control (the regulation is not incorporated into national legislation but is directly applicable). This regulation also defines the rules for the processing of materials containing animal by-products in composting and biogas plants. The regulation applies also to the following catering wastes:

i. Originating from meane of transport operating internationally,

II.. Intended for animal feeding,

iii. Intended for use in biogas or composting plants.

Regulation (EC) No 1774/2002 divides organic materials Into three categories according to hygienic risks:

a. Category 1 material - this includes, among others, catering waste from means of transport operating internationally.

b. Category 2 material - this includes, among others, manure and digestive tract content.

c. Category 3 material - this includes, among others:

- Animal by-products derived from the production of products Intended for human consumption, including degreased bones and greaves;

- Former foodstuffs of animal origin, other than catering waste, which are no longer intended for human consumption for commercial reasons or due to problems of manufacturing or packaging defects;

- Catering waste except for waste from means of transport operating internationally.

It is important that even a small amount of material from the higher category means higher categorization and thus also stricter conditions for handling this material.

Category 1 materials must be disposed of and no recycling technologies are allowed. For some category 2 materials, anaerobic digestion and composting are also possible, which are also possible for all category 3 materials.

When processing biodegradable municipal waste, taking into account the hygienisation requirements imposed by Regulation (EC) No 1774/2002, it is necessary to grind the waste to particles with a maximum dimension of 12 mm and the waste must remain above the temperature of 70 ^e C for 60 minutes. It follows from the above, that from the requirements of the Regulation (EC) No 1774/2002 it results, that composting of catering waste is only possible in closed bioreactors equipped with automatic temperature measurement. Digestion of catering waste is only possible on biogas stations with a hygienisation grade. Waste producers, who currently give its catering waste for feeding , will have to seek new ways of recovery or disposal of these wastes in the coming period. This becomes an opportunity for some composting plants and biogas stations to get waste for processing. Waste will require high hygienisation requirements, but at the same time the fee for the use of this waste should be significantly higher than for other wastes. The requirements of the regulation will have to be complied with by existing composting plants using municipal bio-waste collected in a sorted collection, which also contain catering wastes. This will relate to the vast majority of separate collection systems for bio-waste in the Slovak Republic. The increased cost of using catering waste will have to be paid by the waste producers in the increased fee for the use of this waste.

Based on the above, efforts have been made, to solve this problem, and the result of this effort is the design for the construction of a. container hygieniser for biodegradable wastes and a method of hygienisation thereof according to the submitted invention.

Substance o/f the Invention

The above-mentioned drawbacks are substantially eliminated by the container hygieniser for biodegradable wastes and a method of hygienisation thereof according to the submitted invention. The substance of the hygieniser construction consists in the fact that it consists of two hygienisation columns, between which a water heating column is located,, whereby the hygienisation columns are composed of at least two above each other horizontally placed cylindrical hygienisation tanks interconnected by the first connecting pipes with the filling inlet in the upper hygienisation tank and outlet in the lower hygienisation tank. Thereby, a sludge pump is included in the forced circulation branch between the. upper hygienisation tank and the lower hygienisation tank. The water heating column for the content in the hygienisation tanks is composed of at least two above each other horizontally placed cylindrical water tanks interconnected by second connecting pipes with cold water inlet into the upper water tank and the water shower system piping) through the heated water outlet from the lower water tank and a water pump. Thereby, a system of heat exchangers placed fnside of the hygienisatfon tanks is by its inlet connected to the water pump outlet and by its outlet connected to the upper water tank or the system of heat exchangers is by its inlet and outlet connected to the outlet from the external hot water heat source and to the inlet to the external hot water heat source. An external hot water heat source may be, for example, a biogas station. Between the upper water tank and the lower water tank is a water pump and a system of heat exchangers placed inside the hygienisation tanks included, in the forced circulation branch. The hygienisation tanks have a. built-in screw mixing system. The screw mixing system is connected via a hydromotor to a hydroaggregate. Microwave two -band heating sources are associated to the hygienisation tanks on the outside. Water tanks have: a built-in electric water heating system. Hygienisation tanks have a built-in water shower system. The container arrangement requires the hygienisation columns and the water heating column to be embedded in the support frame structure. In the support frame structure also the space of the machine room is reserved. The container hygieniser for biodegradable municipal wastes contains also additional accessories as temperature gauges, liquid level sensors, pressure relief valves and distribution valves not shown.

In the above-described container hygieniser for biodegradable wastes, a method of hygienisation of biodegradable municipal waste is implemented, the substance of which is that the liquid mixture of biodegradable municipal wastes crushed to the fraction of max. 1.2 mm and water is exposed to a combined two-band microwave heating and hot water heating to the minimum charge core temperature of 70°C for at least 1 hour with simultaneous horizontal screw mixing in hygienisation tanks and with simultaneous continuous vertical transposition of the liquid mixture of biodegradable municipal wastes between the inlet and outlet hygienisation tank.

In the method of hygienisation of biodegradable municipal wastes, It is also important to prepare the material that is to be processed. The processed waste is collected in the barrets and subsequently ground to smaller pieces in the waste crushing device. The device is supplied with its own control and connected to an electrical power source. The operator manually starts the device and manually doses the waste. By starting the device the mixer screws turn on. Depending on the waste structure, the operator manually doses the necessary amount of water into the mixer. Once the desired structure of waste in the mixer has been reached, the mixer is emptied using a sludge pump that fills the empty hygienisation tanks of the left hygienisation column and subsequently of the right hygienisation column up to the required level of the upper hygienisation tank. When empty hygienisation tanks are filled, simultaneous mixing of the material occurs. After filling the appropriate hygienisation column, the heating process begins. The mixture in the individual hygrenisation tanks of the hygieniser is heated to 70" C. The material is heated for 60 minutes and during this time the temperature must not fall even in one tank below 70°C. The measured temperature values are archived and processed In a chart or table for a control by a hygienist. If the temperature in any hygienisation tank drops below 70'C, the repetition of the entire cycle takes place, Upon completion of the heating process, the content of the hygieniser is drained Into the cooling tank. Subsequently, the hygieniser is flushed with warm water,

The advantages of the container hygieniser for biodegradable wastes and the method of its hygienisation according to the invention are evident from the effects that are manifested externally. In general, it is possible to state that the originality of the submitted device is that the requirements of the Regulation (EC) No 1774/2002 at the processing of biodegradable municipal waste with hygienisation. grade are fulfilled.

Overview of figures on the drawings

Container hygieniser for biodegradable wastes and a method of hygienisation thereof according to the Invention wilt be clarified in more detail in the drawings, in which Fig. 1 is a side, view of the construction of a hygieniser. Fig. 2 Is a front view of the construction of a hygieniser. Fig. 3 is a technological scheme of hydraulic branches and heating.

The examples of embodiments

It is understood that the individual embodiments according to the invention are intended to be illustrative and not limiting technical solutions. Those skilled In the art will find or will be able to ascertain, using no more than routine experimentation, many equivalents to the specific embodiments of the invention. Also such equivalents will fall within the scope of the following claims,

For those skilled in the art, it would be no problem to make an optimal design of the construction and the selection of its elements. For this reason, these features have not been addressed in detail.

Example 1

In this example of a particular embodiment, a container hygieniser for biodegradable municipal wastes according to the invention is described, as shown in Fig.. 1 to 3. The hygieniser construction consists of two hygienisation columns, between which a water heating column is located, whereby the hygienisation columns are composed of three above each other horizontally placed cylindrical hygienisation tanks 1 interconnected by the first connecting pipes 2 with the filling inlet 15 in the upper hygienisation tank 1 and outlet 16 of the processed material in the lower hygienisation tank 1. Thereby, a sludge pump 4 is included in the forced circulation branch 3. between the upper hygienisation tank 1 and the lower hygienisation tank 1. The water heating column for the content in the hygienisation tanks 1 is composed of three above each other horizontally placed cylindrical water tanks ^.interconnected by second connecting pipes g, with cold water inlet 7 into the upper water tank 5_ and the water shower system 22, piping through the heated water outlet 8 from the lower water tank 5 and a water pump £. Thereby, a system of heat exchangers 10. placed inside of the hygienisation tanks 1 is by its inlet connected to the water pump outlet 9_ and by its outlet connected to the upper water tank 5 or the system of heat exchangers IS. is by its inlet and outlet connected to the outlet 24 from the external hot water heat source and to the inlet 25 to the external hot water heat source. The hygienisation tanks 1 have a built-in screw mixing system 14. The screw mixing system 14 is connected via a hydromotor 12. to a hydroaggregate IB.

Microwave two-band heating sources 20 are associated to the hygienisation tanks 1 on the outside. Water tanks 5 have a built-in electric water heating system 23. Hygienisation tanks 1 have a built-in water shower system 2£. The container arrangement requires the hygienisation columns and the water heating column to be embedded in the support frame structure 19. In the support frame structure also the space of the machine room H is reserved. The container hygieniser for biodegradable municipal wastes contains also additional accessories temperature gauges 21, liquid level sensors 12L pressure relief valves 1 7. and distribution valves not shown. Example 2

In this example of a particular embodiment, a method of hygienisation of biodegradable municipal wastes according to the invention is described, operated on the above-described container hygieniser for biodegradable wastes described in Example 1 . In the method according to the invention, the liquid mixture of biodegradable municipal wastes crushed to the fraction of max. 1 ,2 mm and water ie exposed to combined two-band microwave heating and hot water heating to the minimum charge core temperature of 7Q°C for at least 1 hour with simultaneous horizontal screw mixing in hygienisation tanks and with simultaneous continuous vertical transposition of the liquid mixture of biodegradable municipal wastes between the inlet and outlet hygienisation tank.

Industrial usability

The industrial usability of the container hygieniser for biodegradable wastes and a method of hygienisation thereof according to the invention are especially in the field of waste processing.

1 - hygienisation tank

2 - first connecting pipes

3 - forced circulation branch

4 - sludge pump

5 - water tank

6 - second connecting pipes

7 - cold water inlet

8 • heated water outlet

9 - water pump

10 - heat exchanger

11 - space of the machine room

12 - hydromator

13 - level sensor

14 - screw mixing system

15 - filling inlet

16 - outlet of the processed material

17 . pressure relief valve

18 - hydroaggregate

19 - frame structure

20 - microwave two-band heating source

21 - temperature gauge

22 - water shower system

23 - electric water heating system

24 - outlet, from the external hot water heat source

25 - inlet to the external hot water heat source