RU2309592C2 - Bakery oven - Google Patents

Abstract

FIELD: baking industry.

SUBSTANCE: bakery oven has distribution chamber formed as box with three branch pipes provided through its three vertical sides and communicating with one another through feed gas flues. Branch pipes have rectangular section. Two of said branch pipes positioned on opposite sides of distribution chamber are curved at an angle and arranged in horizontal position. Discharge gas flues are communicating with box-like collecting chamber which is connected with recirculation fan through converging tube and straight branch pipe.

EFFECT: reduced consumption of power for baking of bakery products.

2 dwg

Description

The invention relates to the baking industry of the food industry, namely to tunnel bakery ovens based on the recirculation of combustion products, and can be used to produce a wide range of bakery products.

Known baking oven, which contains a tunnel baking chamber, conveyor under, consisting of working and idle branches, a heating system including a combustion device, connecting ducts, upper front and rear, as well as lower front and rear U-shaped channels, consisting of heating bunches pipes connected by their inlet sections to distribution manifolds (1).

A disadvantage of the known furnace is the low accuracy of heat supply to the zones of the baking chamber due to the lack of flexible multi-channel distribution of combustion products entering the furnace heating pipes. This leads to irrational thermal effects on baked dough pieces and excessive fuel consumption.

The closest analogue to the claimed oven is a baking oven containing a tunnel baking chamber, consisting of three zones with working and idle branches of the mesh conveyor located in it. The furnace heating system includes a furnace, a cylindrical distribution chamber with inlet ducts for upper and lower heating, which are equipped with distribution manifolds with perforated gates, U-shaped tubular channels connected by inlet sections to the distribution manifolds, exhaust ducts in communication with a recirculation fan (2) .

A disadvantage of the known furnace is the excessive consumption of fuel and electric energy on the drive of the recirculation fan, due to the fact that the heating system of the known furnace has a large aerodynamic resistance

The technical result to which the claimed invention is directed is to reduce energy costs for baking bakery products, which is achieved by reducing the aerodynamic drag of individual elements of the heating system.

The specified technical result is achieved due to the fact that in a baking oven containing a tunnel baking chamber, consisting of three zones with working and idle branches of the mesh conveyor located in it, and a heating system including a furnace, a distribution chamber with three outlets in communication with the supply gas ducts, distribution manifolds with perforated gates, U-shaped tubular channels and exhaust ducts, the distribution chamber is made in the form of a duct, its branches have a straight section They are located on three vertical sides, with two distribution chamber taps located on opposite sides of it being bent at an angle and placed horizontally, the exhaust ducts are in communication with a box-type collecting chamber, which is connected to the recirculation fan by means of a confuser and a straight pipe, and heat transfer walls of distribution manifolds parallel to the working branch of the conveyor are provided with screens.

The described design of the baking oven, which provides for the distribution and collecting chambers in the form of boxes, the taps of the distribution chamber in such a way that their cross section has a rectangular shape, the execution of two of them located on two opposite sides of the distribution chamber, bent at an angle and their horizontal placement, as well as the communication of the collecting chamber with the suction pipe of the recirculation fan by means of a confuser and a straight pipe, it allows high throughput of combustion products by reducing the aerodynamic resistance of individual elements of the heating system, while not only reducing the cost of electric energy to drive the recirculation fan, but also the consumption of combusted fuel, which ultimately reduces the cost of baked bakery products.

The invention is illustrated by drawings:

figure 1 shows a longitudinal section of a baking oven;

figure 2 is a view of the furnace from above (view along arrow A in figure 1 with a partial horizontal section).

The bakery oven contains a tunnel baking chamber 1, consisting of three zones with adjustable heat supply: front, middle and rear, each of which has separate regulation of the upper and lower heat supplies. In the baking chamber there is a working branch 2 and an idle branch 3 of a mesh conveyor, a steam humidifier 4 and a heating system. The furnace heating system includes a furnace device 5, a distribution chamber 6, made in the form of a duct with three branches 7, 8 and 9, located on its three vertical sides, having a rectangular cross-section and communicated with the supply ducts 10, 11, and 12. Two branch 7 and 8, the distribution chamber 6, located on its two opposite sides, are made curved at an angle and placed horizontally. The furnace heating system also includes upper front and rear and lower front and rear distribution manifolds 13, 14, 15 and 16, respectively, with perforated gates 17. Gates 17 are designed to control the flow area of each inlet section of the heating pipes of the U-shaped upper front, middle and rear and lower front, middle and rear tubular channels 18, 19, 20, 21, 22 and 23, respectively. To remove the exhaust products of combustion from the U-shaped channels, exhaust gas ducts 24 are connected with the box-type collecting chamber 25. The chamber 25 is connected to the suction pipe of the recirculation fan 26 by means of a confuser 27 and a straight pipe 28. To mitigate heat shock directed to the baked products, heat transfer the walls 29 of the distribution manifolds parallel to the working branch 2 of the conveyor are provided with screens 30.

A baking oven operates as follows.

When burning fuel in the combustion device 5, the combustion products having a high temperature are mixed with part of the exhaust combustion products. Further, the mixture of combustion products in a distribution chamber 6 made in the form of a duct is divided into three streams, which are directed through bends 7, 8 and 9 located on its three vertical sides, having a rectangular cross-section, into the supply ducts 10, 11 and 12. In this case the cross-sectional shape of the bends 7, 8 and 9, as well as the implementation of the distribution chamber 6 in the form of a duct provide a large throughput of the combustion products. The flows directed from the distribution chamber 6 to the supply gas ducts 10, 11 through outlets 7 and 8, located horizontally on two opposite sides of the chamber 6 and made curved at an angle, fall into the front upper and lower distribution manifolds 13 and 15, respectively. The implementation of the bends 7 and 8 bent at an angle and their horizontal location provides less resistance to the moving flow of combustion products. The flow directed through the outlet 9 and the supply duct 12, enters the rear upper and lower distribution manifolds 14 and 16, respectively. In the distribution manifolds, a secondary separation of the combustion products occurs due to a change in the position of the perforated gates 17. When moving the combustion products in the heating pipes of the U-shaped channels 18, 19, 20, 21, 22, and 23, heat is transferred to the corresponding zones of the baking chamber 1 of the furnace. At the same time, due to a change in the amount of combustion products sent to individual channels of the heating system, regulation of heat supply to various baking zones is provided. The exhaust products of combustion are discharged from the channels 18-23 through the exhaust gas ducts 24. Next, the products of combustion enter the box-type collecting chamber 25 and are sucked from it by a recirculation fan 26, with a suction pipe of which the collecting chamber 25 is communicated by means of a confuser 27 and a direct pipe 28. Communication of the collecting chambers with a recirculation fan through a confuser and a straight pipe ensures a smooth increase in the flow rate of exhaust gases entering the fan inlet pipe and 26, and helps to reduce the energy consumption of the fan drive. Then the recirculation fan 26 sends part of the combustion products to the combustion device 5, and the other part to the chimney 31.

Thus, the invention allows to reduce energy costs for baking bakery products. It is achieved by reducing the aerodynamic drag of individual elements of the furnace heating system: a distribution chamber, its taps and a collecting chamber with a confuser and a straight pipe. This reduces not only the cost of electric energy to drive the recirculation fan, but also the consumption of combustible fuel.

Information sources

1. Patent of the Russian Federation No. 2138951, 10.10.1999.

2. Patent of the Russian Federation No. 2186495, 08/10/2001.

Claims (1)

A bakery oven, characterized in that it contains a tunnel baking chamber, consisting of three zones with working and idle branches of the mesh conveyor located in it and a heating system, including a combustion device in communication with a distribution chamber made in the form of a box with three outlets located from three its vertical sides in communication with the supply ducts and having a rectangular cross-section, distribution manifolds with perforated gates, U-shaped tubular channels and exhaust gas ducts ducts connected to the box-type collecting chamber, which is connected to the recirculation fan by means of a confuser and a straight pipe, and the two distribution chamber taps located on opposite sides are made curved at an angle and placed horizontally, while the heat transfer walls of the distribution manifolds are parallel to the working branch of the conveyor, equipped with screens.

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