SU33451A1 - The method of drying materials - Google Patents

Description

The main task in drying various products is to remove moisture (water) by vaporization through evaporation and to dry the product a continuous flow of heat is required, which is supplied in some dryers through the heated walls of the apparatus to the product being dried using the thermal conductivity of the walls. In vacuum dryers, the dried product HOM is deposited in a rarefied space, and the heat influx, as in the above dryers, also occurs through the thermal conductivity of the chamber walls. At the same time, the product being dried, obtaining heat by means of thermal conductivity, dries gradually from the outer to the inner layer. The layer of the product closest to the wall of the chamber dries quickly and, after drying, the crust does not conduct well to the heat of the product, resulting in slow drying, requiring a lot of heat and fuel consumption.

The proposed method of drying, in order to produce it using the heat that is generated during the compression of air, without using special devices for heating it, to the air introduced from the outside into: The drying chamber, is communicated alternately between compression and then high frequency expansion,

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when the number of changes is about 300 per minute, with the use of blowing out a portion of the exhaust air towards the end of the expansion.

In an apparatus for carrying out the method described, the material is loaded into a grid box placed in a drying chamber, which is connected via a channel with a gate to the cavity of a compressor cylinder. When the piston moves in the direction towards the chamber, the cylinder and the cylinder cavity, air is compressed, and when the piston moves back at the end of the stroke, its air is blown through the exhaust pipe connected to the cylinder cavity.

In the drawing, FIG. 1 shows a longitudinal section of a device for drying materials; FIG. 2 - its top view; FIG. 3 is a front view of it.

When drying any product (carrots, chicory, etc.) at room temperature (15 ° -20 °), evaporation is slow because the air in the pores of the product as it evaporates is saturated with water vapor. For further drying, it is necessary to apply heat, which increases the temperature and makes possible further evaporation, or, without heat supply, remove the moistened air in the pores, replacing

firo dry. In order to carry out the drying, without using special devices for heating the air, a method of drying is proposed, by giving the external air a variable pressure, either compressing or expanding at a higher frequency when the number is 300 changes per minute, using the heat produced by compressing the air and blowing a part by the end of its expansion.

In the device for carrying out the proposed method, the drying chamber / is connected to the cavity 2 of the compressor cylinder connected on one side to the exhaust pipe 16, and on the other to the closed chamber 3 into which external air flows.

For the purpose of continuity of drying, two drying chambers / are used, of which one chamber is in operation, and the second at this time is unloaded and loaded with a new batch of material. The doors of the drying chamber open at the hinges and are sealed with rubber rings in the groove. There are thumbwheels 12 for pressing the doors. A box 4 for loading material is introduced into the chamber with a small gap between its walls and the chamber for the passage of air. The box 4 is provided with small wheels 10 for rolling the box out of the chamber. When drying some materials, depending on their porosity, the dimensions of the chamber should be reduced in order to maintain a constant free volume and, consequently, a fixed maximum air pressure and a corresponding temperature, for which box 4 can be partially filled with extraneous inlays. The degree of loading of the camera, you can adjust the temperature of drying. To determine the temperature in the chamber, a thermometer 8 is inserted into it, the end of which is placed in cap 9. For determining the pressure, there is a manometer 7 on two atmospheres, located above the small chamber 6, in which a check valve is installed, in order for the manometer to show the highest constant pressure (with no doubt). In the channel connecting the drying chamber 7 to the cavity 2 of the compressor cylinder, a shutter 5 serving to turn the chamber on and off is installed. Porsche 19 has several sealing piston rings, and the cylinder itself is made without cooling, since during compression the maximum temperature reaches 70 °. For a uniform stroke, a flywheel is mounted on the shaft, and a pulley 77 serves to actuate the device. For ease of loading and unloading, a trolley 13 mounted on the rails 18, on which the loaded box 4 is brought from the loading compartment, as well as taken away during unloading after drying. When the piston 19 moves towards the drying chamber, the air from the cavity 2 of the compressor cylinder is compressed both in it and in the drying chamber, and at the same time fresh dry external air is sucked into the closed chamber 3 through the valve 75 through the pipe 14. During the reverse movement of the piston 19, the humidified air from the drying chamber 7 is exhausted into the cavity 2 of the cylinder, and in the chamber 3 the air is compressed. Then, when the piston comes to the extreme right position and the cavity 2 of the cylinder is filled with humidified discharged air, the piston opens at the end of the stroke the purge window of the pipe 77 and the exhausted air from the chamber rushes in order to blow into the cavity 2 of the cylinder with a strong vortex motion directed by the comb on the piston and removes humidified air from it through the exhaust pipe 16, replacing it with dry air.

This cycle of compression and vacuum in the drying chamber 7 is repeated up to 300 times per minute, so that the moisture is quickly removed from the material being dried.

The subject matter of the invention. 1. A method of drying materials, characterized in that the external air introduced into the drying chamber is alternately compressed, then expanded at a high frequency, with a number of changes of about 300 per minute, using a blown end of expansion at the part of the exhausted air, which method is designed to produce drying using the heat that is transmitted to the air when it is compressed, without using special devices to heat this air.

2. An apparatus for carrying out the method according to claim 1, characterized by the use of a drying chamber / connected by means of a channel blocked by a vane 5 with a cavity 2 of a compressor cylinder, connected on one side to an exhaust pipe 16, and on the other, via a pipe / 7, - with a closed chamber 3 having a valve 15 in the walls for receiving through it external air from the pipe 14, which the compressor serves, when the piston 19 moves in the direction of the drying chamber, to compress

in it and in the cavity 2 of the air, and during the reverse movement of the piston - to compress the air in chamber 3 and transfer it at the end of its stroke through the tube / 7 into the cavity 2 in order to purge it.

3. In the device according to claim 2, use dp of loading the material of the lattice box 4 introduced into the drying chamber /, what is the box for the purpose of preservation, in connection with the degree of porosity of the material, constant in terms of free volume, and hence the maximum pressure air may be partially filled with extraneous tabs.

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