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(11) Patent Number: KE 102
(45) Date of grant: 11/03/2005
(12) PATENT
(51) Int.Cl.6: F 26B 19/00
(21) Application Number: 1997/000202
(22) Filling Date: 04/03/1997
(73) Owner: NAUCHNO-PROIZVODSTVENNOE OBEDINENE Masshinostroenijaof, 33 Gagarina 143952, Russian Federation
(72) Inventor: EFREMOV Gerbert Aleksandrovich; KUSHNER Boris larailovich; KOCHNEV Igor Aleksandrovich, and SMIRNOV Aleksandr Sergeevich
(74) Agentiaddress for correspondence: W.R.McA SPENCE, P.O.Box 43984, Nairobi, Kenya.
 
(54) Title: APPARATUS FOR CURVING MATERIAL
(57) Abstract: The present invention relates to agriculture, to be exact to apparatus for curing, for example, tobacco and may be applied to apparatus for curing different products, materials and objects wherein solar heat radiation is used as additional source of energy.
 
APPARATUS FOR CURING MATERIAL
The present invention relates to agriculture, to be more exact to apparatus for curing material. The invention may be exploited most effectively for curing tobacco, when solar energy is used as additional source of heat. Besides, the invention may be used for curving different materials, for instance, such as rice, tea, wood, fish and the like.
At present all over the world the curing of different materials requires a great deal of energy, generally received in the course of burning organic fuel -oil-products, gas, coal, wood and so forth. The process of burning leads to increasing the percentage of carbonic acid and to reducing the rate of oxygen in the atmospheric air; in its turn it increases the hotbed effect and has a most negative influence on the environment.
For example, in order to cure a kilograms of tobacco it is necessary to burn about 1-2 kilos of conventional fuel. Every year all over the world hundreds of thousands tons of tobacco are produced. It is cured mainly by applying a duct-fire method; it means that hundreds of thousands tons of coal and wood are burnt, forests on vast territories being cut down for this purpose.
That is why now there is a problem of finding alternative energy sources for curing different materials.
We know, that there was invented the apparatus for curing tobacco (UK Patent Application GB 2015317, A) comprising a compartment for containing tobacco to be cured; a solar heating compartment for tobacco to be cured; solar heat radiation absorption means; non-solar heating means for heating air other than by solar radiation; a heated-air compartment; a fan system for causing air to flow into the apparatus; control means for controlling flows of air as well as the temperature and humidity of cured material.
 
The solar heat radiation absorption means are located at the top of the apparatus (along the roof of the building) just above the compartment for containing tobacco to be cured and the heated-air compartment. The solar panels comprise a matrix consisting of steel turnings made into a mat. The mat is supported on a welded wire mesh frame and covered with a wire mesh net to hold it on the frame.
However, the above-mentioned constructive location of the solar heat radiation absorption means (only at the top of the apparatus) does not allow to use solar energy most effectively. It means that the share of solar heat radiation in the over-all amount of energy necessary for curing tobacco is rather low.
Besides, the mentioned solar heat radiation absorption means are of the consumption characterized that is they create a directed flow of air heated by solar radiation which must be further transferred into the compartment for containing tobacco. With this view complicated constructive units are provided, what makes the whole construction of the apparatus too complicated and expensive. In this case the consumption of solar heat is possible only in daytime, as heat is transferred by a flow of air from the solar heat radiation absorption means into the compartment for containing tobacco, wherein it is consumed for curing. The: described construction of the apparatus makes it impossible to retain solar heat absorbed during daytime for its consumption at night time.
The present invention is aimed at creating such an apparatus for curing material, which would enable to increase the share of solar heat radiation in the over-all amount of energy required for curing and thus to reduce the over-all consumption of energy and to improve the environmental ecology.
These and other aims are attained by creating an apparatus for curing material comprising: a compartment for containing material to be cured with side walls and the roof; heating air means for heating air in the mentioned compartment; a fan system in the mentioned compartment; solar heat radiation absorption means mounted at the top of the compartment for containing material to be cured. According to the invention the additional solar heat radiation absorption means are mounted on the side walls of the compartment.
The mounting of the solar heat radiation absorption means on the whole surface outside the compartment for containing material to be cured enables to increase the share of solar energy in the over-all amount of energy required for curing material and thus to reduce energy consumption necessary for curing by reducing twice as much the amount of fuel required for achieving the necessary temperature in the compartment for containing material to be cured.
The location of the solar heat radiation absorption means both on the side walls and the roof of only one apparatus mentioned above enables to save from cutting down about two hectares of woods yearly, that is why the employment of the apparatus all over the world would allow to save woods on vast territories, what in its turn would have a positive effect on ecology.
It is expedient that the solar heat radiation absorption means should be mounted on the side walls and the roof with a clearance in relation to their outside surface, what a provides for heat exchange excluding its convective component.
The specified location of the solar energy absorption means together with the all above-mentioned increase the thermal resistance of the compartment for containing material to be cured, since the mentioned air clearances serve as perfect thermal insulators and considerably reduce heat loss in the environment when solar radiation is not available. That is why the offered apparatus operates effectively not only when illuminated by the Sun but at night as well, that is twenty-four hours.
The mentioned clearance should be defined with a view to the possible condition of the outside surface of the compartment for containing material to be cured and the prevailing direction of the heat flow through this clearance to the mentioned compartment.
 
Therefore, it is desirable that the clearance between the solar heat radiation absorption means and the outside surface of the side walls and the roof of the compartment should be 8 mm and less. In this case heat exchange within the clearance will go on exceptionally owing to thermal conductivity and radiation, while convection causing great heat losses will be completely excluded.
It is expedient that the solar heat radiation absorption means should include a great number of non-consumption solar panels covering the outside surface of the side walls and the roof with crossing vertical and horizontal rows. Each non-consumption solar panel is a hollow closed cell comprising a frame on one side of which a transparent screen is rigidly fixed and on the opposite side a solar energy receiver is also rigidly fixed. The solar energy receiveris a plate the inner surface of which is coated with material characterized by a high solar energy absorption coefficient and a low degree of blackness. There is a clearance between the inner surface of the transparent screen and that of the plate of the receiver measuring 0, 05-0, 15 of the ratio of the plate area to its perimeter.
The specified construction of each solar panel affords an opportunity to make it non-consumption that is to create a panel which accumulates solar energy and transfers its heat into the compartment for containing material to be cured directly through its side walls and the roof.
Therewith vanishes necessity to produce flows of air heated by solar energy and directed into the compartment for containing material to be cured. This simplifies the construction of the offered apparatus.
Moreover the above-mentioned clearance between the inner surface of the transparent screen and that of the plate of the receiver together with the described clearance between the solar panel and the outside surface of the side walls and the roof of the compartment provide the maximum heat flow towards the indicated outside surface and minimal heat losses in the environment.
During the day this solar panel accumulates solar energy and transfers its heat into the compartment for containing material to be cured; and at night (when the incidence of solar radiation is zero) the solar panel operates as thermal insulator, that is the mentioned air clearances reduce heat losses by means of thermal conductivity, and the receiver of solar radiation energy coated with material having a low degree of blackness reduces heat losses by means of radiation.
When the cured material is loaded into the compartment so that as to exceed the volume limited by walls and thus to fill the free space beneath the roof (with a view of using completely the wholevolume of the compartment), on which the above-mentioned solar panels are mounted, a considerable flow of heat is produced blowing from above. That is why the material loaded into the upper section of the compartment (beneath the roof) may be overheated.
The results of both the calculations and experiments show, that when utilizing the described solar panels under conditions of direct solar radiation the temperature of each receiver of solar radiation energy reaches about 200°C. Since the roof is set at an,: angle from the skyline as a result of what it is illuminated much better by the Sun, and the cons traction of the roof is characterized by a considerably higher degree of thermal lag in comparison with the side walls, the mounting of solar panels on the roof leads to a great increase of the temperature of each receiver fixed there and accordingly to the increase of the temperature of the roof construction in the whole.
Therefore in the apparatus, in which it is required to cure material at a temperature lower than that of the roof in order not to overheat top layers of the material, it is advisable to dispose the solar panels on the roof above the upper level of the cured material in the compartment. It is also expedient that the outside surface of the rooflocated below the top layer of the material in the compartment should have thermal insulation in order to reduce heat losses in the environment and to prevent from the condensation of moisture formed in the process of curing material.
Thus, the utilization of the specified invention provides the twenty-four-hour operation of the apparatus for cu ring material and enables the share of solar energy in the over-all quantity of energy required for curing to be substantially increased, and in that way to reduce energy consumption needed for the process of curing as well as to improve the environmental ecology.
To comprehend the invention better some concrete examples of its embodying are given below with reference to the accompanying drawings, wherein:
Figure 1 is an elevation, cut-away view of an apparatus for curing material according to the invention;
Figure 2 is the point A of Figure 1, a large scale;
Figure 3 is a diagram of heat losses from the receiver according to the invention into the environment as a result of thermal conductivity and convection;
Figure 4 is a diagram of heat losses, through the frame of a solar panel according to the invention.
The apparatus for curing material according to the invention comprises a compartment 1 (Figure 1) for containing material to be cured, constructed, for instance,  as a building having side walls 2 and the roof 3. Within the compartment 1 the non-solar heating means 4 for heating air in the compartment 1 is disposed. The non-solar heating means 4 may be of any known construction intended for similar purposes; for example, it may be a duct-fire heating system including a furnace and a duct for furnace gases.
Besides, the apparatus has a system of natural ventilation 5 comprising, for instance,
vent holes in the lower portion of the side walls 2 and on the roof 3. The apparatus also
has the solar energy absorption means 6 mounted on the roof 3 and side walls 2 of the compartment 1 for containing material to be cured. The solar energy absorption means 6 consists of a great number of non-consumption solar panels 7 (Figure 2) covering the outside surface 8 of correspondingly the side walls 2 and the roof 3 with crossing vertical and horizontal rows.
Each non-consumption solar panel 7 is a hollow closed cell comprising a frame 10 on one side of which a transparent screen 11 is rigidly fixed and on the opposite side a receiver 12 of solar heat radiation energy is also rigidly fixed. The receiver 12 is a plate 13, the inner surface of which is coated with material with a high solar energy absorption coefficient and a low degree of blackness. The inner surface of the transparent screen 11 is apart from the inner surface of the plate 13 of the receiver 12; this clearance measuring 0, 05-0, 15 of the ratio of the screen 11 area to its perimeter. The solar energy absorption means 6 (Figure 1) is mounted on the roof 3 and side walls 2 of the compartment 1 with a clearance (Figure 2) in relation to their outside surface whet provides heat exchange excluding its convective component. As a rule, the clearance& 8 mm and less. It means that between the outside surface of each plate 13 of the solar radiation energy receiver 12 and the outside surface 8 of correspondingly the side:walls 2 and the roof 3 there is the above-mentioned clearance Between the frames 0 of adjacent solar panels 7 there is a technological clearance required by the convenience of mounting and the operation of the latter. The mentioned clearances are defined proceeding from the condition of providing minimal heat losses in the environment.
The main losses of the heat flow of solar radiation absorbed by the recover 12 in the environment are defined by thermal conductivity and air convection between the receiver 12 and the transparent screen 11 as well as thermal conductivity and air convection between the receiver 12 and the corresponding frame 10 of each sole- panel 7. The heat transfer coefficient in the clearance S between the receiver 12 and 1-ie transparent screen 11 is proportional to where is a size of this clearance and between the receiver 12 and the frame 10 of the transfer coefficient is proportional to 1/(r. With enlarging the clearance 34heat losses between the receiver 12 and the transparent screen 11 are reducing, while heat losses between the receiver 12 and the frame 10 are increasing as a result of enlarging the surface area of the frame 10.
  
C - a proportion coefficient, Wt/m
P - the perimeter of the plate 13 of the receiver 12, m.
The diagram of the alteration of the function Q in correspondence with ᶑ given in Figure 4.
Therefore, the mounting of the suggested solar panels 7 with regard to the mentioned clearances S and 4provides for the maximum efficient use of solar energy, heat losses in the environment being minimal.
Solar panels 7 on the outside surface 8 of the roof 3 may be mounted above the upper level of the cured material in the compartment 1. The portion of the roof 3 on which the solar panels 7 are not mounted should have thermal insulation 15, for instance, cell-closed foam plastics.
The number of solar panels 7 depends on the size of the compartment 1. For instance, the apparatus for curing tobacco embodying the invention and having in the plan the basic dimensions of 5m 6.5 m carries 120 solar panels 7, each being 1 m long and 1 m wide. The clearance between the transparent screen 11 and the receiver 12 of each solar panel 7 is 25 mm. And the clearance between the plate 13 of the receiver 12 and the outside surface of the side walls 2 and the roof 3 is 7 mm. The solar panels 7 on the roof 3 are mounted above the upper level of the leaf tobacco loaded in the compartment 1 and the other part of the surface of the roof 3 is covered with thermal isolation 15 made of foam plastics.
Thus, the utilization of the described apparatus for curing material enables to considerably increase the share of solar energy in the over-all amount of energy consumption, required for curing material.
Besides, in this case:
- there is no need for additional energy necessary to blow air through the solar panels into the compartment filled with the cured material, since the solar panels are constructed as non-consumption;
- heat losses in the environment through the transparent screen are significantly reduced due to a considerable reduction of convection;
- there are no heat losses through the outside surface of the plate of the receiver, since heat from the receiver is transferred directly by the outside surface of the side walls and the roof of the compartment for containing material to be cured.
The trial which was carried out using the apparatus for curing material according to the invention and as described above showed, that for curing 3800 kilos of green leaf tobacco with the help of the offered solar panels the actual surface area of which is 120 m the share of solar energy in the over-all consumption of energy required for its curing was 37%.
The apparatus described above operates in the following way:
The receivers 12 of the solar panels 7 absorb solar heat radiation and thus become heated, and heat from them is transferred by thermal conductivity and radiation to the sidewalls 2 and the roof of the compartment 1 within which the material iscured, when the system of duct-fire heating and that of natural ventilation are at work. In case the incidence of radiation from the Sun is low or zero the solar panels 7 operate as thermal insulators and owing to the clearances Standized enable minimal heat losses in the environment.
 
CLAIMS
1. Apparatus for curing material comprising:
- a compartment for containing material to be cured with side walls and the roof; - non-solar heating means for heating air other than by solar radiation in the mentioned compartment and installed in it;
- a fan system for ventilating the mentioned compartment;
- solar heat radiation absorption means mounted on the side walls and the roof of the compartment for containing material to be cured.
2. Apparatus according to claim 1, wherein the solar heat radiation absorption means are mounted on the side walls and the roof with a clearance in relation to their outside surface providing for heat exchange excluding a convective component.
3. Apparatus according to claim 2, wherein the clearance between the solar heat radiation absorption means and the outside surface of correspondingly the side walls and the roof of the compartment is 8 mm or less.
4. Apparatus according to claim 3, wherein the solar heat radiation absorption means comprises a great number of non-consumption solar panels covering the outside surface of the side walls and the roof with crossing vertical and horizontal rows. Each non-consumption solar panel comprises a hollow closed cell with a frame on one side of which a transparent screen is fixed and on the other side a solar heat radiation receiver is mounted. The receiver is a plate the inner surface of which is coated with material characterized by a high coefficient of solar energy absorption and a low degree of blackness. The inner surface of the transparent screen is apart from that of the plate of the receiver, the clearance measuring from 0, 05 to 0, 15 of the ratio of the plate area to its perimeter.
 
6. Apparatus according to claim 4, wherein the solar panels are mounted on the outside surface of the roof above the upper level of the material loaded in the compartment; a part of the outside surface of the roof, which is free from solar panels, is covered with thermal insulating material.
 
APPARATUS FOR CURING MATERIAL
Summary
The present invention relates to agriculture, to be exact to apparatus for curing, for example, tobacco and may be applied to apparatus for curing different products, materials and objects wherein solar heat radiation is used as additional source of energy.
The purpose of the invention is to increase the share of solar energy consumption in the over-all balance of energy required for curing and to reduce energy consumption needed for the curing process.
The offered apparatus for curing comprises a compartment (1) for containing material to be cured, a fan system (5), non-solar heating means (4) for heating air other than by solar energy and solar heat radiation absorption means (6) constructed in the form of non-consumption solar panels (7) mounted on the outside surface (8) of side walls (2) and the roof (3) of the compartment (1). The best effect is achieved through the optimum geometric dimensions of the mounting of the solar panels (7) elements in the relationship to each other and the outside surface (8) of the side walls (2) and the roof (3) of the compartment (1).  

 

 

 

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