SU679654A1 - Method of primary treatment of cocoons - Google Patents

Description

one

The invention relates to textile npoMfcBimeHHOcTH, in particular, to the primary processing of silkworm cocoons.

The closest to the described invention according to the technical essence and the achieved result is a method of treating cocoons, which involves wrapping by freezing the pupae in a liquid gas environment, for example, in liquid nitrogen, followed by drying the cocoons with heated air 1.

This method, preserving the original physicomechanical properties of the cocoons, has significant drawbacks, which are / that the mass treatment of fresh cocoons requires a significant amount of liquefied gas, which sharply reflects on the efficiency of the treatment process, and shadow drying takes a long time, which is determined by , 5 + 2 months, and significant specially equipped areas.

The aim of the present invention is to increase the effectiveness of the pitch treatment of cocoons by preserving the physicomechanical properties

This goal is achieved by the fact that the sea wall is carried out in an environment of liquid nitrogen vapor at a temperature of (-90) - (- 150) ° C, and the drying is carried out in an air flow at a temperature not exceeding 60 ° C, for example, in a mode of decreasing temperature in three stages at the temperature of each of them, respectively: 55 + bs, 40 + 45 C, 30 + 35 C.

Distinctive features of the present invention are the use of liquid nitrogen vapor for the wrack and moisture sublimation of the pupa, and for sushi - air with a temperature not higher than

When the cocoons are harvested by the proposed method, four main tasks are solved: first, nitrogen, due to its unsuitability for breathing, plays the role of a choking gas; secondly, the low temperature of the vapor of liquid nitrogen acts as a refrigerant for the deep cooling of the pupa and promotes the sublimation of moisture from it; thirdly, a stream of liquid nitrogen vapors serves to remove the sublimated portion of the moisture and the chamber; and fourth, due to its inertness at low temperatures

and low activity at relatively low positive temperatures, nitrogen contributes to the preservation of the initial physical and mechanical properties of the cocoons.

The process of morka and sublimation of the pupal moisture can be carried out in the whole range of low temperatures, but from the point of view of economy and productivity, optimal

is the limit of temperatures lying in the range from (-90) to -150) since temperatures below (-150) C require increased consumption of liquid nitrogen without significant time gain, and above (-90) C require a longer time for sublimation moisture pupae. The data of this study are presented in the table.

Claims (1)

The process technology is as follows. The working zone of the cocoon of a cocoon is divided into two thermal regions: the first is the region of decreasing temperature, the second is the region of increasing temperature. On the verge of two areas - the zone of lowest temperatures. The processing of cocoons begins at the beginning of the first region, i.e., the cocoons arrive with the ambient temperature, then they, advancing, for example, on a cannon, are gradually cooled by moving towards liquid nitrogen vapor. At the border of the two regions, the cocoons are cooled to deep low temperatures created at this point by nitrogen vapor, then they are heated by a countercurrent of heated gas, nitrogen. Liquid nitrogen vapors are rtsacted from the fresh cocoon loading area, warmed to 55-60 °, dehydrated and injected in the discharge area, which results in a whip cycle for drying and drying cocoons in a nitrogen environment. The heated nitrogen, moving towards the cooled cocoon, gives off heat and in the zone of the lowest temperatures fits sufficiently cooled. The cocoons are dried in subsequent zones at temperatures of 40-45 ° C and 30-35 ° C. It is also possible to dry them in the same area at 30-35 ° C, but this will require an increase in processing times. The drawing shows a diagram of one of the possible variants of a device implementing this method. In the case, which is a metal structure, the conveyors 1, 2, 3, and 4 are located in Rus. The carrier belt of the conveyor 1 is enclosed in a heat-insulated tunnel made in the form of a pipe. The edges of the conveyor belt and the removable upper half of the pipe form a closed working tape, divided into sections by sealing and dividing partitions mounted on the conveyor belt. The bearing parts of the remaining conveyors are wire mesh attached to two parallel branches of roller chains. The width of the conveyors is enclosed by hard sides so that the cocoons do not fall off them. Thermal zones of the dryer are divided by partitions. At the end of each conveyor, trays 5, 6 are installed to guide the cocoons when pouring from one conveyor to another. The gas pipeline 7 of the first conveyor 1 is a rigid pipe connected by the front part to the fan 8, which is connected to the suction nozzle, and the rear pipe to the inlet of the heater 9. A condensate separator 10 is installed between the heater 9 and the delivery nozzle 10. In the middle part of the working zone of the conveyor 1 A system 11 is provided for starting liquid nitrogen vapors. In the front of the first conveyor 1. there is a loading device 12 with a drum 13 for adjusting the thickness of the cocoon layer and, depending on the layer specified. specifying the speed of movement of the metering conveyor 14. The temperature mode of the second and third zones is supported by heaters 15, 16 and automatic control fans 17, 18, 19 and 20 with special sensors. Conveyor 21 dry cocoons fall into the distributors of automatic scales 22. The temperature regime of the working zone of the first conveyor is; in the area of loading - (+15) - (+20) С; in the middle part - (-90) - (-150) С; in the area of cocoon unloading - (+55) (+60) ° С. Fresh cocoons, moving into the zones of the first conveyor, are gradually cooled to deep negative temperatures. When this occurs, the mica and the sublimation of moisture of the pupae occur. Passing the minimum temperature point (liquid nitrogen vapor launch region), gradually heats up the current of the heated gas and loses a significant part of moisture — part of the freeze-dried moisture is removed. The final drying of the cocoons occurs on the second and third conveyors, the air temperature in which, respectively: 40-45 C and 30-35 ° C. If we take into account that factors such as the number of defects during primary processing, the technological qualities of the cocoons during unwinding / the physicomechanical properties of the silk produced, the quality of products made from this silk, and so on, depend directly on the initial processing of the cocoons of the silkworm. ., then the feasibility of the use of the proposed method can be very significant. Claims The method of preprocessing cocoons, including morku by freezing the pupae, followed by drying with heated air, characterized in that, in order to increase the processing efficiency by preserving the physicomechanical properties of the cocoons, morki is carried out in an environment of liquid nitrogen vapor at a temperature (-90) - (-150) С, and drying is carried out in three stages at a temperature on each of them, respectively: 55-60 s, 40-45 C, 30-35 C. Sources of information taken into account during the examination 1, Copyright certificate USSR 346410, cl. D 01 B 7/02, 1971,