RU2015470C1 - Loose material vacuum dryer - Google Patents

Abstract

FIELD: drying. SUBSTANCE: conveyer netted belt and a drive drum are made with windows. The size and the pitch of the belt and drum windows are equal. Unloading chutes are additionally mounted inside the drum at an angle to its generatrix. EFFECT: improved structure. 3 dwg

Description

 The invention relates to techniques for vacuum drying food thermosensitive products, mainly bulk materials, and can be used in food enterprises and in other processing industries.

 Known single and multi-tier continuous belt dryers for drying bulk materials, operating both under vacuum and at atmospheric pressure. For example, a VTI single-band direct-flow dryer for corrugated and granular materials [1], containing a drying corridor divided into four zones, a furnace, a displacement chamber, and a conveyor in the form of a plate mesh strip.

 The disadvantage of the installation is the low intensification of heat and mass transfer due to the lack of mixing of the dried material over the thickness of the layer.

 Known single-belt continuous dryer for bulk materials [1], containing a plate conveyor, cultivators, a steam heater, centrifugal and suction fans.

 The disadvantage of this dryer is the insufficient intensification of the process of heat and mass transfer by installed agitators, which are two rolls with fingers.

 The closest in technical essence to the proposed one is a continuous belt vacuum dryer for bulk materials [2], which contains a housing with a vacuum and water vapor removal system and a belt conveyor mounted inside it, heating elements, loading and unloading devices.

 The disadvantages of the installation are the low intensification of the process of heat and mass transfer, as well as the fact that the reverse stroke of the tape is not used.

 The purpose of the invention is the intensification of the process of heat and mass transfer.

 This goal is achieved by the fact that in a continuous vacuum dryer for bulk materials, including a housing with a vacuum and water vapor removal system and a belt conveyor mounted inside it, heating elements, loading and unloading devices, the conveyor is equipped with several swivel rollers located in a zigzag sequence. The conveyor belt enveloping the drive roller, made in the form of a drum, is made mesh with special windows. The driving drum is provided with windows along the generatrix, the size and location of which is equal to the size and location of the inter-window mesh parts of the conveyor belt. Inside the drum under the windows are unloading chutes, made at an angle to the generatrix of the drum, equal to the angle of repose of the dried product.

 Based on the research conducted on the sources of patent and scientific and technical information, we can conclude that the set of essential features is new and allows to intensify the process of heat and mass transfer.

 Technical solutions whose properties would coincide with the properties of the claimed, not found. Therefore, the invention meets the criterion of "significant differences".

 In FIG. 1 shows a continuous vacuum dryer for bulk materials; figure 2 - driving drum; figure 3 - mesh belt conveyor with windows.

 The installation comprises a loading hopper 1, loading and unloading shut-off valves 2 and 3, a housing 4 connected to a vacuum pump and a water vapor condenser by means of a pipe 5, a driving drum 6 with windows 7 and unloading chutes 8, rotary rollers 9, intermediate rollers 10, mesh tape conveyor 11 with windows 12, heating elements 13 in the form of IR emitters, inspection windows 14, guides 15 and 16 of the drying product 17, the drive 18 of dry material 19.

 The dryer operates as follows. A portion of bulk material 17 from the hopper 1 connected to the vacuum system through the loading shut-off valve 2, along the guides 16 gets into the preheated and evacuated installation on the mesh part of the tape 11. When the drive drum 6 rotates with an angular speed of 0.01-0.05 about / min, the dried material 17 moves along the upper branch of the conveyor between the IR emitter 13, loosening when the belt passes through the supporting rollers 10. Using rotary rollers 9, windows 12 in the conveyor and guides 15 feeding the product to the lower part of the conveyor branch, where the process of dehydration of the material continues under the influence of IR irradiators 10. Through windows 7, the product enters the drive drum 6 into the unloading chutes 8, from which it pours out of the drum 6 into the drive 18 of dry material 19 by gravity , which is removed from the latter by means of shut-off valve 3 and an unloading hopper (not shown) connected to a vacuum system.

Advantages of the proposed installation: the drying process intensifies when the product moves on a mesh tape between the IR irradiator and stirring when pouring one branch of the conveyor to another; the intensification of heat and mass transfer will contribute to loosening of the dried material when the tape moves through the intermediate rollers; the ability to select the optimal drying mode on the upper and lower branches of the conveyor;
the possibility of implementing a mild dehydration mode for heat-sensitive products at a high drying speed; the possibility of drying the material, if necessary, in the drum by installing additional sources of radiation; due to the use of several swivel rollers and conveyor belts, the windows use a reverse run of the belt.

Claims (1)

 A VACUUM DRYER FOR BULK MATERIALS, comprising a housing with a mesh belt conveyor located therein, heating elements, material loading and unloading devices, characterized in that, in order to intensify the drying process, the conveyor is equipped with rollers installed in a zigzag sequence, and the mesh belt has windows while the leading element of the conveyor is made in the form of a drum with windows along its generatrix, and unloading chutes are additionally installed inside it at an angle to the generatrix, the size and step of the eye tape and the drum are equal.

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