Assoc.
Prof. V.Yu. Ovsyannikov, graduate
student A.A. Korchinskiy,
student A.S. Moskalenko
Thermograph study of the process of freezing the blood
of
large livestock
The perfection
engineering and technology on processing of the second raw material of meat
industry is extremely urgent task. One of the most important methods, during
processing of the blood of large livestock is the action of low temperatures,
used both for canning of the blood by means of the freezing, and its
concentration the freezing out method of the moisture [1]. In connection with
this in the article the study of the process of freezing the blood of large
livestock, which makes it possible to most fully produce the estimation of
processes and phenomena, which take place in the blood under the action of low
temperature, is examined.
The eutectic points
of complex solutions during the freezing are different from the eutectic points
of the separate clean components of solution.
For such solutions
there is an eutectic temperature zone, in limits of which occurs the
crystallization of moisture. The definition of such temperature zones for any
materials, which are undergone freezing and freezing moisture, is extremely
necessary for the correct selection of the regime parameters [2]. Liquid
biotechnological media, that are been the complex biological systems, in which
the eutectic temperature so is determined not unambiguously, but it can be
presented in the form to the totality of the points of the phase transformation
[3].
Is carried out the
experimental determination of eutectic temperature zones for the blood of large
livestock (LL) and concentrated blood LL by the method of differential thermal
analysis. Eutectic temperature zones were defined for the media during their
freezing being investigated.
n the samples under
investigation of the blood LL and of the concentrated blood LL by refractometric method was determined the content of dry
matter, which they comprised: for the blood LL – 19,0 %, while for the
concentrated blood LL 31,7 %. Research of the process of freezing was conducted
in the range of temperatures 258…298 k. The registration of temperatures was
accomplished with the aid of the universal microprocessor two-channel gauge-
regulator of temperatures of brand TRM 202, of that equipped with the
collection of Chromel-Copel thermocouples. The
obtained values of temperatures are represented in the graphic form in Fig. 1,
2.
Differential
thermal analysis was carried out as follows. In the freezer of the cooling
installation, which has temperature 247 K were placed equal measured volumes
(30 ml) the substance being investigated and the standard substance – of the
dehydrated glycerin, whose thermo physical characteristics were close to the
characteristics of the substances in temperature the range being investigated.
The process of
freezing the substances being investigated is characterized by the presence of
several abrupt changes in the direction of the curved differential record of
temperatures, which reflect temperatures of the phase transitions, designated
by the sections of the simple record: a – supercooling
medium; a-b – the formation of the crystal seeds of ice and the beginning of
crystallization; b - c- d - further intensive crystallization of moisture; d-f
– cooling the crystallized eutectic solution.
Fig. 1. Thermogram of
freezing the blood KRS with the content of dry veshchestv
Ssv = 19.0 %:
1 – the
indication of thermocouple; 2 – the indication of the differential thermocouple.
Fig. 2. Thermogram of
freezing the blood KRS with the content of dry veshchestv
Ssv = 31.7 %:
1 – the
indication of thermocouple; 2 – the indication of the differential thermocouple.
The process of
freezing the substances being investigated is characterized by the presence of
several abrupt changes in the direction of the curved differential record of
temperatures, which reflect temperatures of the phase transitions, designated
by the sections of the simple record: a – supercooling
medium; a-b – the formation of the crystal seeds of ice and the beginning of
crystallization; b-c-d - further intensive crystallization of moisture; d-f –
cooling the crystallized eutectic solution [4].
The carried out
analysis shows that the differential thermogram of
freezing reflects the picture of the phase transitions of moisture in the
samples under investigation most fully. During the freezing in connection with
the supercooling the complete crystallization of
moisture in the biotechnological medium is achieved at a temperature
considerably of of lower than the temperature of
eutectic concentration. The carried out thermograph analysis for all samples
under investigation of the blood LL and the concentrated blood LL made it
possible to sufficiently accurately reveal exothermic processes during the
crystallization of moisture.
The temperature
zones, revealed by means of the method of differential thermal analysis, the
characteristic specific phase transitions in the process of crystallizing the
moisture, showed that the thermophysical nature of
this process is complex. The process of freezing medium the dependence rel.un. of the form, content of dry matter and chemical
composition occurs at different temperatures and with different intensity [5].
Literature
1. Ovsyannikov V.Yu.
Concentration of the plasma of the blood of large livestock by freezing. Meat
industry. 2013. ¹ 7. pp. 47-49.
2. Antipov S.T., Ovsyannikov V.Yu., Kondratyeva Ya.I. Kinetics of the
process of concentration by freezing cherry juice. Bulletin of the
3. Ovsyannikov V.Yu.,
Bostynets N.I., Denezhnaya A.N., Kraminova Yu.S. Thermophysical special features of freezing food media.
International student scientific bulletin.
2015. ¹ 3-1. pp. 69.
4. Antipov S.T., Yashchenco
S.M., Ovsyannikov V.Yu.
Study of the cooling process spirited infusions spicy aromatic plant products. Storage
and processing of agricultural raw materials. 2000.
¹ 11. pp. 68-69.
5. Ovsyannikov V.Yu., Kondratyeva Ya.I., Bostynets N.I., Denezhnaya A.N. Investigation
of the process of freezing and thawing of fruit juices. Bulletin of the
6. Ovsyannikov V.Yu.,
Bostynets N.I., Denezhnaya A.N., Kondratyeva Ya.I. Control of the
process of low-temperature concentration of liquid media by freezing. Automation.
Modern technologies. 2016. ¹ 2. pp. 10-13.