RU2430630C1 - Method for heating single food semi-products moving rectilinearly on conveyer - Google Patents

Abstract

FIELD: food industry. ^ SUBSTANCE: invention relates to the field of food production. According to the proposed method semi-products are heated from above with directed infrared radiation perpendicular to the semi-products movement pattern, with the radiators of this radiation positioned over the semi-products, uniformly relative to them along the length and width with minimum adjustable clearance between the radiators and the semi-products. The conveyer is designed in the form of endless thin flat conveyer belt which is heated along the length of the positioned semi-products with infrared radiation perpendicular to the belt plane with the radiators of this radiation positioned under the belt uniformly along the length and width relative to its flat surface with minimum adjustable clearance between the radiators and the belt; the semi-products are additionally heated with this radiation penetrating through the belt; radiation power and density are regulated close to the semi-products. ^ EFFECT: invention allows to essentially reduce materials consumption of devices implementing its operations, enhance reliability, durability, safety. ^ 3 dwg

Description

The present invention relates to food production technology and can be used for continuous heating, or baking, or drying, or roasting, or roasting, or baking food semi-finished products, i.e. for their heat treatment. Including - until the complete preparation of the finished food product from them. The method can be used for the preparation of semi-finished products: steaks, steaks, meatballs, meatballs, for baking breads, rolls, cookies and gingerbread cookies, for heating the first and second dishes in containers, for drying crackers, cereals, herbs, berries, mushrooms, etc. P.

The method can be used for continuous heat treatment of building, engineering, instrument-making, biotechnological semi-finished products and thermoplastic materials in molds.

1. The prior art

A known method of heating piece food semi-finished products on a conveyor, in which the conveyor is placed inside the lined body (inside the hearth) of the tunnel furnace, which creates a loading window for loading piece semi-finished products on the conveyor. Inside the casing (hearth), gaseous fuel is continuously burned, maintaining a predetermined high temperature inside the casing (hearth), while simultaneously removing the products of fuel combustion (through smoke tubes). During the heating of semi-finished products on top of the housing (hearth), superheated steam from the steam generator is periodically fed inside to moisten semi-finished products that lose moisture [1, 2].

The disadvantages of this method are the complexity of the operations, huge material consumption, high energy intensity of operations, environmental pollution by the products of fuel combustion and its thermal pollution. Similar disadvantages have similar methods described in the sources [3-12]. Even more complicated is the method according to the application RU [13], in which, for heating, the operation of heating with electric heaters (heating elements) is additionally used (for the operation of burning fuel).

Similar methods for heating semi-finished products are known, in which the high temperature inside the body (inside the hearth) of the tunnel kiln is created and supported by electric heaters (TENs) [14-16]. These methods do not pollute the environment with fuel combustion products and exclude thermal pollution of the environment. Their disadvantages are the complexity of the operations, the huge material consumption and high energy consumption of operations due to the small outer surface of the heating elements and the long heating time of the air (due to its low thermal conductivity) inside the furnace body (hearth).

2. The closest technical solution (prototype) is a method for heating piece technical products in a tunnel kiln moving rectilinearly in a conveyor, described in [17, 18] (combined prototype).

In this method, the conveyor is made of separate interlocked bogies moving rectilinearly along the lined body (hearth) of the furnace, along the rails inside it, and air heating inside the body (hearth) is carried out by electric heaters (heating elements) or radiating tubes, which are fixedly placed in rows and above heated items and under carts.

The main objectives of the invention (in comparison with the prototype) is to obtain the following technical results.

1) Simplification of the implementation of the method of heating food piece semi-finished products moving rectilinearly on the conveyor;

2) Reduction of material consumption of the structural elements of the method;

3) Reducing the cost of electrical energy for heating.

3. Reasons that hinder the receipt of technical results.

The most significant disadvantages of this method (prototype) are the complexity of the operations, the huge material consumption and high energy intensity of operations.

3.1. The complexity of the method lies in the need to create a lined case (sub) of a tunnel (or any other furnace from known methods of heating piece products) furnaces, create a conveyor moving inside this case (hearth) at high temperatures, create carts, lay rails for them, to create a foundation for rails, to provide lubrication for the wheels of bogies operating at high temperatures, as well as the need to create and maintain a steam generator and a steam line for supplying steam into the body (in the sub) Lids for humidification, etc. The same drawback is inherent for cradle conveyors in analogues [1, 2].

3.2. The huge material consumption is due to the massiveness of the lined housing (hearth) of the furnace, conveyor elements and steam humidification elements.

3.3. The high energy intensity of operations is due to the large consumption of electric energy for heating and the drive, given the massiveness of the moving parts of the conveyor and the large energy losses due to friction in these moving parts (in links).

In fact, it is necessary to heat only semi-finished products, while in the prototype only a small part of the thermal (primary - electric) energy of electric heaters is spent on heating products.

Electric heaters pos.2 (figure 1) in the prototype [18] are placed not over products with a minimum clearance with them, but in the upper part of the internal cavity of the body (hearth). These heaters (heating elements or radiating tubes) have the property that they heat the air surrounding them, creating convection, when the air comes into contact with the heated surface of the heater, and the heated air rises. The placement of electric heaters pos.2 (in the prototype) leads to air heating by convection only under the ceiling of the body (hearth) of the furnace. These heaters (heating elements or radiating tubes) have the property that they create thermal (electromagnetic) radiation. But TENs or radiating tubes, due to the low temperature of the outer surface (700-900 ° C), generate radiation with a rather large wavelength ≈3.2 μm and a rather small specific radiation power ≈5 · 10 ⁵ W / cm ² [19, p.29, fig. 2-5]. Whereas the known sources of directional infrared radiation (infrared mirror electric bulbs with a mirror reflector inside the bulb, which creates directional radiation) of the ICZ type (infrared mirror) [20], with a nominal spiral temperature of 2350K create a specific power of directed infrared radiation ≈2 · 10 ⁷ W / cm ² (19, p. 29, Fig. 2-5), i.e. ≈ 40 times more powerful at the same energy costs. Electric heaters (heating elements or radiating tubes) create uniformly dispersed thermal (partially infrared) radiation from a cylindrical surface. It partially heats the ceiling of the furnace body (hearth), partially surrounding air and only partially the product (semi-finished product).

It is also known that the energy of electromagnetic radiation in the infrared spectrum is best absorbed (heated) by carbon and silicon [21], and of metals - by chromium [22].

Electric heaters pos. 3 (Fig. 1) in the prototype [18] are placed under massive trolleys and, like electric heaters 2) heat the surrounding air partially with convection and partially with radiation. Part of the radiation energy is spent on heating the air. Other parts of this energy are spent on heating the carts 4 from below and on heating a massive foundation (base) along with rails (with guides 6). Thus, only a tiny fraction of the electric power (thermal energy of electric heaters - heating elements or radiating tubes) is spent on heating the semi-finished products (products) themselves.

On the other hand, the large masses of the lined body, conveyor parts, cradles or trolleys, foundations (bases) create a greater inertia of the heating process. Heating of semi-finished products (products) can begin only after the air and carts have warmed up (cradles - in analogues). To heat up everything that is not a semi-finished product, much more energy is consumed in time than is necessary to maintain the necessary temperatures of the semi-finished products.

4. Signs of the prototype, coinciding with the claimed invention.

Partial heating of semi-finished products during their rectilinear movement on the conveyor by thermal, partially infrared, infrared radiation.

5. The objectives of the invention are the following technical results.

5.1. Simplification of the implementation of the method of heating food piece semi-finished products moving rectilinearly on the conveyor.

5.2. The decrease in material consumption of the structural elements of the method.

5.3. Reducing the cost of electrical energy for heating.

6. These technical results in the claimed method of heating food semi-finished products moving rectilinearly on the conveyor are achieved by heating them with directed infrared radiation perpendicular to the path of the semi-finished products, from above, placing emitters of this radiation over the semi-finished products, uniformly with respect to them in length and width, with minimum adjustable gap between emitters and semi-finished products, and the conveyor is made in the form of an endless thin conveyor flat belt, which is heated, for a length non-disposable semi-finished products, directed by infrared radiation perpendicular to the plane of the tape, placing the emitters of this radiation under the tape uniformly in length and width relative to its flat surface, with a minimum adjustable gap between the emitters and the tape, while the semi-finished products are heated by the same radiation additionally penetrating through the tape, and the radiation power and its density near the semi-finished products are regulated.

7. The essence of the invention is illustrated by drawings, where figure 1 presents the technological scheme that implements the inventive method (plan view);

figure 2 shows the heating region of the semi-finished products in cross section of the technological scheme;

figure 3 presents a diagram of the electrical power of the emitters of directional infrared radiation.

The letters in FIGS. 1-3 correspond to the following:

VGUL - the upper horizontal section of the tape;

ST - fixed table;

NIKI - directional infrared radiation;

PIKI - penetrating infrared radiation;

ν is the linear velocity;

U _NETWORKS - electrical voltage of an industrial network.

7.1. The technological scheme that implements the inventive method includes the following structural elements.

Positions 1 through 9 (Fig. 1) - kinematic transmission of a flexible, infinite, flat and thin conveyor belt, including 1 - flexible, infinite, flat, thin conveyor belt made of stainless steel wire mesh 1A (Fig. 2) with a chromium content of at least 17% (for example, 12X181H10T), a thickness of less than 1 mm, or from a perforated strip of such steel of the same thickness, or from carbon fiber fabric 1B (Fig. 2) of the same thickness.

Tape 1 (Fig. 1) is tightened around the drive cylinder 2, supporting cylinders 3 and 4, as well as the tension cylinder 5. The drive cylinder 2 is kinematically connected 6 (for example, V-belt drive) with a controlled drive 7 (drive control unit 7 on drawings - not shown).

Cylinders 2-4 are placed in the stationary housings 8 of their own bearings, and the housing 8 is fixedly mounted on a fixed frame (symbolically designated pos. 9).

The own bearings of the tension cylinder 5, on both sides of the cylinder 5, are mounted on the ends of the freely swinging levers 5A, the opposite ends of which are mounted by means of cylindrical hinges in the fixed bearings 8A, fixedly mounted on the same frame 9, with the possibility of tensioning the tape 1 with its own weight of the cylinder 5.

Cylinders 2-5 are placed on the frame 9 parallel to each other, horizontally, forming a rectangle elongated along the horizontal, at the corners of which are located geometrically parallel to the axis of rotation of the cylinders 2-5. In this case, the tape 1, covering the cylinders 2-5, has one upper horizontal section of the tape - VGUL (leading horizontal section of the kinematic transmission of the flexible tape 1) kinematically stretched tape 1 and one horizontal section from the bottom (not indicated in figure 1).

Above the VGUL, parallel to the tape 1 and with a uniform clearance relative to it, on the length of the interaxal distance of the cylinders 3 and 4, uniformly along the length of this distance and the width of the tape 1, the 10B emitters (the upper radiators relative to the VGUL) directed to the tape 1 of the NIKI infrared radiation are fixedly installed (in Fig. 1, the arrows indicate the direction of the NIKI, and in Fig. 2 the arrows show the shape of the flow of the NIKI from the emitters 10B). Emitters 10B (for example, infrared reflector tubes IK3175, or IK3250, or IK3500 [20], depending on the required maximum heating power of the semi-finished products 14 by means of electric EP cartridges (Fig. 2), are fixedly connected to the dielectric (for example, from PCB) plate 11B ( the upper dielectric plate relative to the tape 1), which corresponds to the length of the interaxal distance between the cylinders 3 and 4 (Fig. 1), and the length to the width of the tape 1 (Fig. 2). The plate 11B is mounted in vertical stationary guides 12 with the possibility of tikalnogo plane-parallel plate 11B move relative VGUL strip 1 with its subsequent fixing in the guide 12 by, for example, symbols of screws 13. The fixed vertical guide 12 is also fixedly mounted on the frame 9 (in Figures 1 and 2 is indicated in phantom).

Under VGUL parallel to the tape 1 and with a uniform gap relative to it on the length between the cylinders 3 and 4, uniformly mounted emitters 10H (lower relative to the VGUL radiators) of the infrared radiation of NIKI (in Fig. 1, the arrows indicate the direction of NIKI, and in Fig. 2, by arrows, the shape of the flow of NIKI from emitters 10B is shown). The emitters 10H are mounted similarly to the emitters 10B by means of electric EP cartridges on a dielectric plate 11H (lower relative to the VGUL), which corresponds in length to the distance between the cylinders 3 and 4 (Fig. 1), and in length to the width of the tape 1 (Fig. 2). Plate 11H is mounted similarly to plate 11B.

On a rectilinear section VGUL tape 1 (Fig.1) or 1A (1B) (Fig.2) uniformly or unevenly along the length and width of this section are piece food semi-finished products 14, which, for example, are continuously fed (in the beginning, in the direction of the tape 1, plot VGUL) on the VGUL tape 1 conveyor 15 (shown conditionally in figure 1). At the end, in the direction of travel of the tape 1, the VGUL section along the generatrix of the cylinder 3 with a minimum clearance relative to the tape 1, covering the cylinder 3, the edge of the stationary flat table ST (for example, fixedly attached to the stationary frame 8 (Fig. 1) is placed so that the upper plane is inclined to the horizontal at an acute angle.

The upper (relative to VGUL) emitters 10V (electric lamps IK3) are electrically parallel through a thyristor voltage regulator 16 with a manual control potentiometer (not shown in Fig. 3) are electrically connected to an alternating voltage U of a power industrial network. The control dial (on the axis of the potentiometer) in figure 3 is indicated by pos.17. Similarly, emitters 10V to the industrial electric network with voltage U, the lower (relative to VGUL) emitters 10H are electrically connected (Fig.3).

7.2. Declared as the invention, the heating method is implemented as follows.

Before you start the flowchart (figure 1, 2, 3) to work, i.e. before starting the continuous (in-line) heating of food piece semi-finished products 14, moving rectilinearly on the VGUL section of the conveyor belt 1, under the NIKI 10B emitters, the technological scheme (elements of its device) is adjusted to the specified heating mode. In this regard, the emitters 10H under the VGUL by means of plane-parallel movement of the plate 11H in the guides 12 are set with a minimum clearance relative to the tape 1, for example, 5 mm, after which their position is fixed by clamping screws 13. Considering the dimensions of the semi-finished products 14, the emitters 10B above the semi-finished products 14 by means of plane-parallel the movement of the plate 11B in the guides 12 is set with a minimum clearance relative to the semi-finished products 14, for example, 10 mm Next, power is supplied to the U _NETWORK through the regulators 16 to the emitters 10B and 10H at the same time. The emitters 10B create NIKI, directed from top to bottom above the VGUL section of tape 1, uniformly along the length and width of the tape 1 in this section, and the emitters 10H create NIKI, directed from the bottom up to the tape 1 (VGUL section) between the cylinders 3 and 4 uniformly in length and the width of the tape 1 in this section.

After that, at the same time, the controlled electric drive 7 of the conveyor belt (pos. 2-8) and the drive of the feed conveyor 15 are turned on, loading the food semi-finished products prepared for heating 14. From the conveyor 15, the food semi-finished products 14 prepared for heating enter the heating area of the VGUL tape 1 under the directional on top of them NIKI created by emitters 10B, on the outer surface of tape 1 heated by means of NIKI emitters 10H in the VGUL section, and also under the penetrating infrared radiation P directed at them from below IKI created by 10N emitters. Moving rectilinearly on the conveyor belt 1, on its VGUL section, the semi-finished products 14 are heated by NIKI from above and from below by heat transfer from heated tape 1 from below and by penetrating infrared radiation PIKI. The heating temperature of the semi-finished products 14 increases as they move together with the tape 1 with a speed ν. Processed by heating, the semi-finished products come from tape 1 (from its rectilinear section of VGUL) to the fixed table ST (Fig. 1).

Depending on the requirements for finished piece food products from semi-finished products, for example, heating, or baking, or drying, or frying, or roasting, or baking, when setting up the technological scheme (Figs. 1, 2, 3) empirically (control unit, not shown in the drawings, controlled electric drive 7) select the speed ν of the movement of the semi-finished products 14 in the heating zone - VGUL (the residence time of the semi-finished products 14 in this zone). The handle 17 of the potentiometer on the regulators 16 (Fig.3) change the voltage supply of the emitters NIKI 10V and 10H (power NIKI and PIKI, i.e. the intensity of radiation heating of the semi-finished products 14 on the site VGUL). Plane-parallel vertical movement of the plates 11B and 11H with emitters 10B and 10H, respectively, in the guides 12, with their subsequent fixation with screws 13, change the gap between the emitters 10B and the semi-finished products 14 from above, and between the emitters 10H and tape 1 - from the bottom (change the density of NIKI by the surface of the semi-finished products on top and the density of NIKI on the surface of the tape 1 below on the site VGUL, and thus the intensity of heating of the semi-finished products)

After setting the required technological modes of heating the semi-finished products 14, while maintaining these modes (speed ν, the supply voltage of the emitters 10V and 10H and the gaps between the emitters 10B and the semi-finished products 14 from above, as well as between the emitters 10H and tape 1 in the VGUL section), the production line is started (scheme ) (Fig.1, 2, 3) in continuous continuous production of finished food products from semi-finished products 14.

7.3. Positive results.

The first positive result of the invention, namely, a significant simplification of the implementation of the method of heating food piece semi-finished products moving rectilinearly on the conveyor, is ensured by the fact that it is not necessary to create a lined body (sub) of a tunnel (or any other furnace from known methods of heating piece products) of a furnace to create a conveyor moving inside this case (hearth) at high temperatures, create carts, lay rails for them, create a foundation for rails, provide lubrication of the wheels of carts operating at high temperatures, as well as the need to create and maintain a steam generator and steam line for supplying steam into the body (in the under) of the humidification furnace. As the heating of food semi-finished products 14 on the site VGUL (Fig.1, 2) they partially lose moisture, its content decreases compared with the humidity of the surrounding air. Unlike the prototype and analogs, the humidity of the surrounding air does not change when heating the NIKI, since the air almost does not heat up with this radiation. In addition, NIKI does not interfere with the movement of air flows, and the semi-finished products 14, losing moisture when heated, partially absorb it from the surrounding air unhindered. The second positive result of the invention, namely, a significant reduction in the material consumption of the structural elements of the method is provided due to the absence of a massive lined body (hearth) of the furnace, conveyor elements, steam humidification elements, carts or cradles, conveyor chains, rails, etc.

The third positive result of the invention, namely the reduction in the cost of electric energy for heating, is provided due to the fact that all the energy of NIKI is spent only on heating food semi-finished products. From above, they are heated by NIKI (due to absorption of its energy by the surface) from 10B emitters, and from below - from heated tape 1 (at the VGUL site) due to absorption by tape 1 (containing chrome or carbon) of NIKI energy from 10H emitters and penetrating PIKI through tape 1 due to its small thickness (less than 1 mm). By means of a controlled electric drive 7 voltage regulators 16 and the possibility of plane-parallel movement of the plates 11V and 11H with their subsequent fixation, the optimal (minimum energy costs) modes are set: the speed of movement of the semi-finished products 14, the power of the NIKI from the emitters 10V and 10H and the density of the NIKI on the surface of the semi-finished products 14. Additional positive results (DPR) DPR1. Higher than in analogues and prototype, reliability and durability due to the fact that the drive elements, gears, bearing assemblies and the service area of the device (process) that implements the method are located outside the heating zone of the semi-finished products 14. This also ensures the second additional positive result, namely:

DPR2. Simplification and facilitation of the maintenance of the method during its implementation, as well as a significant increase in the safety of maintenance (service area - outside the zone of possible thermal damage).

8. Sources of information

1. Ostrikov A.N. and others. Workshop on the course "Technological equipment". - Voronezh: Voronezh State Technological Academy, 1999. P.309.

2. Khromeenkov V.M. Technological equipment of bakeries and pasta factories. SPb .: GIORD, 2003. P.496.

3. Application for invention RU No. 2007125862 A, IPC F27B 9/00, publ. 01/20/2009.

4. Patent No. 1281504 A, 07/12/1972.

5. Application for invention RU No. 20091688 C1, 09/27/1997.

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17. Application for invention RU No. 2008136018, IPC C03B 25/08, publ. 03/20/2010.

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19. Jamison R.X. Physics and technology of infrared radiation. M .: Publishing. Soviet Radio, 1965. P.535.

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Claims (1)

A method of heating food piece semi-finished products moving rectilinearly on a conveyor, in which moving semi-finished products are heated by moving them together with the conveyor, characterized in that the semi-finished products are heated with infrared radiation directed perpendicular to their path from above, placing the emitters of this radiation over the semi-finished products evenly relative to them along the length and width with a minimum gap between the emitters and with an adjustable gap between the emitters and semi-finished products, and the conveyor is made in the form endless thin conveyor flat tape, the rectilinearly moving portion of which, together with the semi-finished products, is heated with the infrared radiation directed to the tape from below, perpendicular to the path of its movement, placing the emitters of this radiation under the tape, uniformly along its length and width, with a minimum gap between the radiators and with adjustable gap between the emitters and the tape, while the semi-finished products are additionally heated by the same radiation penetrating through the tape, and the power of the directional infrared radiation and its density near the semi-finished products is regulated.

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