Zhantugulov T.

Kostanai State University named after A. Baitursynov the Republic of Kazakhstan

Extruding of multicomponent forage

One of the reserves of efficiency growth in forage preparation – usage of extruding compound feed in animals ration. Extruding provides effective mechanical impact on forage components, destroys material structure, increases nutritional value and edibility of forage. Herewith it is possible to process old, dry forage, processing is connected with high temperature up to 200ºС and pressure up to 25 MPaS, that promotes elimination of the microbiological content, transmitted through forage, at the expense of extrusive processing the range of forages increases. However extruding is a power-intensive process wherein forage may leak between frame and the end of the screw curl in consequence of which there is forage gumming- up between surface and frame wall therefore efficiency increase of extruder operation is an actual task.

Advanced technologies of compound feed production processed in the agricultural products processing field, confirmed necessity of compound feed extruding, i.e. multicomponent fodder materials, their wastes (including monoforages, monodiets) [1,2,3].

Researches of the processes which are taking place in extruder,it is connected with change of rheological properties of processed materials, according to the construction of extruders for their processing because forage composition changes, dragging coefficient also changes. S. S. Dzhingilbaiev, studying extruding processes of oilseeds, described them in the connection with the laws of keeping and transformations of energy ( the first law of thermodynamics). Made or received heat Qt minus lost heat Ql is equivalent to quantity of the transmitted energy – operations which, in their turn, are defined as common difference from the useful operation on compression of Ad and from the dragging forces hindering carrying out useful operation Ac [4]:

Qt – Ql = Аc – Аd (1)

Operation of dragging forces will respectively change in case of change of processed material composition, for example, in the course of multicomponent materials processing.

Some researchers confirm, that extruder combines a number of operations in one machine, which mixes, compresses, heats, cooks, sterilize, forms. It is necessary to understand that it (extruder) substitutes the whole complex of machines, increasing food value, digestibility of processed material.

Other researchers developed processing modes of barley, corn, wheat for increase of nutrients digestibility and grain disinfecting in extruders. It is recommended to grind grain in hammer grinder before extruding (a sieve with 3 mm diameter mesh) and to humidify to17-18% .

However it is more effective to steam out crushed grain or mixes of grain components before extruding. For this purpose the extruder should be equipped with the mixer – steamer, from which a product is directly sent to the extruder screw.

We conducted the pilot researches on processing of multicomponent forages in the extruder (monoforages, monodiets).

At this way of grain preparation the productivity of the extruder increases by 25-30% [1]. But usage of extruding forages, feed mixes shall be carried out according to a diet of animals feeding, i.e. it shall comply with well- balanced, easily digested forage for animal organism.

At researches conducting the following conditions were taken into account: the rotational frequency of the extruder screw (X1); feed mix humidity (X2 – from 8 to 32%); the filament extrusion device length (X3 – from 32 to 96 mm); skew angle of the screw surface (X4 – from 5 to 25 degrees); diameter of the extruder screw is 70 mm. Quality of the processed material was checked on the content in the extruder of starch and dextrins and compared with the basic material.

Figure 1. Dependence of productivity on the rotational frequency (X1) and the length of the filament extrusion device (X3) - a, dependence of productivity on humidity (X2) and skew angle (X4) –b:

Δ-monoforage (consisting of grain wastes, mill offal homogenous in composition);

- monodiet (consisting of grinded grain, mill offal, straw).

As a result of the researches data processing were received productivity dependences on the reference conditions ( figure 1, and, b).

The analysis of dependences shows that under equal conditions of processing indexes of monoforages are higher, than ones of monodiets. In case of increase in rotational frequency of the screw (X1) and increase of the filament extrusion device length (X3) it occurs the increase in productivity of researched intervals. In case of humidity change of feed mix from 8 to 50% productivity reaches the crest value at 36-40%, in case of change of screw surface skew angle (X4) productivity reaches the crest value in case of monodiet processing at 5 ° angle, in case of monoforage processing at 25 °angle. The result of quality determination confirmed the increase of dextrins quantity to 32%.

Literature:

1 . L.Boiko. Progressive technologies for feed mixes production. Feed mixes №4. Technique and technology. 2005.

2 . Experience of extrusive technologies usage. Feed mixes. №7 Technique and technology.2005

3 . The new extruder – highly nourishing forages from wastes. Technique and technology. Feed mixes №5

4 . S. S. Dzhingilbaiev. Energy and heat transmission of screw extruders. Herald of the national engineering academy of the Republic of Kazakhstan, 2006.