Drying and gas or vapor contact with solids – Apparatus – With means to treat gas or vapor
Patent
1988-10-24
1991-01-01
Bennet, Henry A.
Drying and gas or vapor contact with solids
Apparatus
With means to treat gas or vapor
34181, F26B 300
Patent
active
049809784
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to methods of drying thermosensitive materials and apparatus for carrying out the methods.
DESCRIPTION OF THE PRIOR ART
There are known apparatus for drying thermosensitive materials, for example an apparatus with a fluidized bed (cf., Stabnikov V. N., et al, "Protsessy i apparaty pischevykh proizvodstv" Moscow, the Agropromizdat Publishers, 1985, p. 360).
The apparatus comprises two chambers arranged one above the other and separated by a gas distribution grid. The upper chamber is connected to a gas outlet pipe, a hopper for a moist material to be dried, and a pipe for discharging the dry material.
The moist material is fed from the hopper onto the gas distribution grid. Hot gases forced through the holes in the grid from the lower to the upper chamber at a high velocity act to keep the material in a fluidized state. The dry material is evacuated through the discharge pipe.
This prior art apparatus features a rather low capacity, since during drying thermosensitive materials the temperature of the heat-transfer agent should not be too high, as the product being dried tends to burn. Conversely, drying at low temperatures necessitates a longer contact of the material with the heat-transfer agent and affects the quality of the end product.
There is also known a method of drying thermosensitive materials in a fluidized bed (cf., Sazhin B. S. "Osnovy tekhniki sushki", Moscow, the Khimia Publishers, 1984, p. 91).
A moist material is admitted from a charging hopper to a chamber, where it is entrained by a heat-transfer agent fed through axial nozzles.
In this chamber the material circulates until the dry particles, being lighter in weight, are carried by the heat-transfer agent to a cyclone.
This method, however, fails to obtain a high quality material with uniform moisture content throughout its mass, because the particles of the material travel different paths. The method also fails to dry suspensions and paste-like materials having high moisture content.
There is also known a method of drying thermosensitive materials and an apparatus for carrying out the method (cf., USSR Inventor's Certificate No. 1,192,764, Int. Cl. A 23 B 5/02, published Oct. 17, 1984).
The method involves spraying thermosensitive materials onto inert bodies circulating about a closed space in a flow of heat-transfer agent at a temperature below the temperature of decomposition of such materials.
The apparatus for carrying out the method comprises a cylindrical chamber having an outlet pipe and a tapered bottom in which there is arranged axially of the chamber a blind tube having a base defining with the walls of the bottom an annular passage whereto the heat-transfer agent is admitted. The walls of the chamber accommodate nozzles for feeding moist thermosensitive materials to the chamber.
These methods and apparatus are disadvantageous, since they fail to yield an end product of high quality with low moisture content through the mass of the material.
The method is impossible to carry out continuously for drying highly adhesive materials, and for this reason it is characterized by low efficiency.
SUMMARY OF THE INVENTION
The present invention aims to provide a method of drying thermosensitive materials by preselecting optimum thermal and gas-dynamic conditions, as well as to provide an apparatus for carrying out the method, through arranging inside the housing additional elements ensuring high quality of the dry thermosensitive materials of various adhesive capacities and high efficiency of the drying process.
The aims of the invention are attained in the proposed method of drying thermosensitive food products by spraying such products onto inert bodies circulating about a closed space in a flow or stream of heat-transfer agent at increased temperatures. According to the invention, in the upper part of the flow occupying not more than 1/3 of the horizontal cross-section of the flow, the heat-transfer agent is rotated at an axial velocity 2-3 times higher
REFERENCES:
patent: 3518777 (1970-07-01), Kono
Babin Vladimir V.
Demidov Sergei F.
Mangush Anatoly N.
Martynov Jury V.
Molochnikov Valery V.
Bennet Henry A.
Institut Problem Mekhaniki Akademi, etc.
LandOfFree
Method and apparatus for drying thermosensitive materials does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method and apparatus for drying thermosensitive materials, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and apparatus for drying thermosensitive materials will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1990420