Adam Luberański, Marian Wiercioch, Józef Szlachta, Aleksander Krzyś and Danuta Skalska
Improvement of mechanical milking in the aspect of cow's udder health and maintaining correct milking parameters is possible through e.g. constant improvement of the structure of clusters. A cluster with a specific claw with crossing milk connection pipes Flo-Star Max with liners with a round profile of the barrel of DK1X. The objective of the paper was to analyse usefulness of this type of the sitructure of the machine for mechanical milking of cows. Measurements of simulated milking were carried out in a laboratory to the upper milking pipeline at variable mass intensity of liquid flow within 0-8 kg·min−1, for four penetrations of artificial teats of 100, 75, 62, 50 mm at the systemic negative pressure values within 50 to 44 kPa, simultaneous and alternating pulsation and during real milking of cows in a cowshed. Using a multivariate analysis of variance, the impact of independent variables of an experiment on the values of average vacuum of suction, vacuum fluctuations in cycle, average drop of vacuum in a cycle were proved. Analysis of the machine operation in a milking parallel parlour in real mechanical milking conditions and difficulties in placing a machine on the cow's udder as well as violent milk flow were reported and the milk flow of 3.5 kg·min−1 was exceeded with its characteristic balancing in the rhythm of a pulsator.
Marian Wiercioch, Adam Luberański, Aleksander Krzyś, Danuta Skalska and Józef Szlachta
Air is supplied to a milking machine installation most usually in a constant manner by supply of a small amount of air to a milking chamber of a claw or periodically to a connection pipe of a liner, which enables milk outflow to a milking pipe and improves stabilization of vacuum and limits its fluctuations. On the market of milking machines there is a new solution in the form of mouthpiece vented liners - impulseair®, where air is supplied constantly by a calibrated nozzle in the head of a liner. The objective of the paper was to analyse and assess the selected parameters of milking determined in a milking machine with a claw with fixed volume of a milking chamber (250 cm3) with mouthpiece vented liners in comparison to other solutions used for air supply in milking machines. Measurements were carried out in laboratory conditions with milking to the upper milk pipeline, at variable mass intensities of liquid flow (within 0-8 kg·min−1), for three penetrations of artificial teats (46, 48, 62 mm), at three values of the system vacuum (46, 48 and 50 kPa). A significant impact of the manner of air supply to a milking machine and remaining independent variables of an experiment on the selected milking parameters was proved with the use of a statistical analysis. It was found that a milking unit with mouthpiece vented liners, although it reduces average vacuum of suction [pss], at the same time it limits fluctuations of underpressure in the dp cycle.
Marian Wiercioch, Adam Luberański, Krzysztof Lejman, Małgorzata Fugol and Hubert Prask
A liner is the only part of the milking unit which has a direct contact with a cow’s teat. It ensures a correct circulation of body liquids in a teat with its suitable massage and creates conditions for a teat to open and milk to flow out and maintains a milking cup on a teat. The result of the last task is generation of a suction force that sucks a teat into a liner. During milking, when a cup is placed on a teat, counter forces are generated that try to remove a liner from a teat and forces that cause that a teat moves up to a liner producing a phenomenon of “a climbing cup”. Forces that tend to separate a teat from a liner depend on the mass of a milking cup set and the value of the friction force. A counter force that tends to suck a teat into a liner is proportional to the level of negative pressure in a liner and the surface of cross-section of a teat that is subjected to negative pressure. We should also assume that also the structure of a liner will influence this force. The paper presents results of the laboratory tests on the impact of the shape of the cross-section of a rubber core and construction solutions of liners on the vacuum force of a liner when a teat is sucked into a teat chamber. Eight liners, popular in milking machines used in our country were used in the tests. Various penetrations of a teat (50, 62, 75 and 100 mm), working pressure (25-55 kPa) and a working stage of the milking cup were additional variables. In order to determine whether and what is the degree of the impact of variability sources on shaping the suction forces of a liner, a static processing of results was carried out using a multi-variance analysis. It was proved that at the significance level of α=0.05, the source of variability assumed in the experiment in the form of the liner shape, negative pressure and penetration affected the analysed sizes, i.e. Average values of suction forces in the suction phase (Fws) and massage phase (Fwm). The investigation of the impact of the rubber core part on the determined values of the suction force in the function of variable negative pressure proved that at teat penetration of 50 and 62 mm (the most popular lengths of teats in milked cows), the lowest suction force was observed in case of a liner with a triangular cross-section, slightly bigger with a square cross-section and the highest suction force is generated by round and oval liners.
Małgorzata Smuga-Kogut, Arkadiusz D. Wnuk, Kazimiera Zgórska, Mariusz S. Kubiak, Janusz Wojdalski, Adam Kupczyk, Józef Szlachta and Adam Luberański
This study proposes a method for the production of ethanol from wheat straw lignocellulose where the raw material is chemically processed before hydrolysis and fermentation. The usefulness of wheat straw delignification was evaluated with the use of a 4:1 mixture of 95% ethanol and 65% HNO3 (V). Chemically processed lignocellulose was subjected to enzymatic hydrolysis to produce reducing sugars, which were converted to ethanol in the process of alcoholic fermentation. Chemical processing damages the molecular structure of wheat straw, thus improving ethanol yield. The removal of lignin from straw improves fermentation by eliminating lignin’s negative influence on the growth and viability of yeast cells. Straw pretreatment facilitates enzymatic hydrolysis by increasing the content of reducing sugars and ethanol per g in comparison with untreated wheat straw.