DE1432941A1 - Oven and baking method - Google Patents

Description

PATEN T LAWYERS

DR. ING. E. LIEBAU Our reference 1) Τ.ΙΛ) / ϊί Az 1a V / 6029

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DIPLING. G. LIEBAU Your sign Your message from

Winkler-Atlas Manufacturing Limited Union Road Croydon, Surrey, England

"Oven and Baking Process"

The invention relates to ovens and, more particularly, to tunnel ovens.

! Tunnel kilns with a long tunnel. which the counterntftede to be heated be transported on a conveyor, are well known and well known common, such as in bakeries. Such ovens are generally directly heated by gas burners provided in the tunnel, whereby for

the

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809812 / 0U4

the way such ovens work, the use of a inevitable convection system to promote the Heat transfer has proven beneficial, with the air and combustion chamber gases at the exit end can be withdrawn from the funnels and reinserted into the tunnel through the entry end. However, it is it has often been found that the withdrawn gases are reheated before being reintroduced into the furnace must be, which increases the operating costs.

It has now been found according to the invention that forced convection can be achieved in a more economical manner a more even heat transfer with higher Efficiency can be achieved by a furnace design in which hot, essentially not 'Cooled combustion gases can be introduced into the tunnel.

The object of the invention is accordingly to provide-a Bind provided furnace having a long tunnel, consisting of an inlet chamber and at least one other property with the first mentioned chamber in communication chamber, means duroh for conveying articles the tunnel and one or more first Gas burner h a β Heiznjantels for the entry chamber

Heating of the entry chamber by the Combustion of fuel gas are appropriate while means

909812/0144 ■

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BATH

for heating the further chamber or chambers as well as Means for withdrawing combustion gases from the heating jacket and introducing them directly are provided in a further chamber or at least in one of the further chambers.

The aim of the invention is also to provide a method for producing a baked object, characterized in that the objects to be baked through a tunnel oven with several successive Areas in which the objects are heated, conveyed, the first Area through which the object is transported, indirectly due to the combustion of the fuel gas is heated, while the resulting hot, uncooled combustion gases at least one of the subsequent Areas in contact with the object transported through this area - or Objects - to be supplied.

The further chamber or chambers is or are preferably heated directly by further gas burners that are provided in the tunnel, wherein Shields to the sole of the further chamber or chambers transported objects against excess

direct 909612 / 0U4

direct irradiation are provided while at the same time a substantially free flow of combustion gases to promote convection heat transfer takes place.

The invention will now be described below using an exemplary embodiment described in more detail in connection with the accompanying drawing; show in it:

Figure 1 is a partially sectional side view of a preferred embodiment of the invention Oven for baking pasta etc .;

Fig. 2 is a sectional view along the line II-II of Fig. 1; and

Fig. 3 is a sectional view along the line III-III of Fig. 1.

The tunnel kiln shown in FIG. 1 has an entry chamber 2 and two adjoining further chambers 4 and 6, which are related to the Κε-miner 2 in "connection stand. An endless conveyor belt 10 transports the products to be baked through the continuous tunnel 12, which is made by the related Kemaern is formed.

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The entrance chamber 2 is indirectly with the help of Gas burners 14, 15, 16 and 18 heated, which are arranged in a heating jacket 2 surrounding the chamber. The burner 14 is below the conveyor 10 at the feed end of the furnace for preheating the conveyor arranged, while the burner 15 below the evaporation section of the furnace to avoid excessive cooling is appropriate during continuous evaporation. The burners 16 and 18, respectively are attached above or below the conveyor 10. As gas burners 14, 15, 16 and 18 are preferred Rod band burners are used which extend the width of the chamber in the channels 22 and are completely isolated from the baking area, so that the necessary monitoring of the steam conditions is guaranteed at the furnace entrance.

The second or third area or the chambers 4 and 6 are directly through rod gas burners 24 and 26 heated, which are arranged above or below the conveyor 10. The pass through the areas, Products to be baked are by means of shields 28 - which are attached to the respective burner connect - protected against excessive direct radiation. The shields 28 have a radiation surface for a radiation with a relatively low temperature, so d & ß those to be baked

909912 / OUA. Products

BATH 0 "IGINAL

Products are exposed to weak irradiation, while the combustion gases maintain good natural heat transfer flow freely through the baking chamber by convection.

Mr each area 2, 4 and 6 is a thermoregulator for regulation of the force operated valves in each of the supply lines for fuel for the burners located in the area, so that the '• ßempers.tur in each one of them Range can be increased separately to obtain the desired baking characteristic,.

How great. 2 and 3, the heating jacket 22 of the chamber 2 has an outlet line 30 which is connected via the line 31 to an exhaust line 36 and / or a feed line 34, the latter being along the chambers 4 and 6 each to Le, ge of the component 38 extends, dns is adjustable either to close the entrance to the Abgp.skanal or the entrance to the feed channel. In the outlet line 30, a fan 32 for drawing off combustion gases from the jacket 22 is provided. If the feed line 34 is open, forced convection is obtained in each of the two chambers 4 and 6 or in both chambers 4 and 6, with the fan blowing the exhausted combustion gases into the feed line 34 and from there through some injection pipes 36 into the (Eunnel 12. the injection pipes 36 are along the dining · ■ line 34-distributed and each have corresponding holes β for uniform distribution of the hot combustion gas in the chambers 4 and 6 oeuf. each of the

80S812 / 014Ä injection tubes

Contains injection pipes, a valve for changing resp. Regulation of forced convection.

A wing 40 is provided in one wall of the shell 22, which is adjustable to the jacket 22 with the chamber 4 on to bring a level with the burners 24 in connection. ! If the burners inr> erbnlb 'of the jacket 22 during a certain baking process must be turned off - what. those to maintain the desired degree of forced convection required amount of combustion gas is insufficient, the wing 40 can be opened so that additional combustion gases can flow into the jacket to supplement the gases generated by the heaters 14, 15, 16 and 18.

If forced convection is not required, the feed line can be used 34 shut off and the combustion gases are withdrawn from the jacket 22 through the exhaust duct 36.

The lines 42 and 44 are centered in the chambers 4 and above the surface of the conveyor for continuous ■ extraction of gas from the chambers while the furnace is working intended. Each of these lines has a fan that ever according to whether a compulsory convention is necessary or not adjustable can be operated to the desired Amount of that taken from the kernels

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Maintain G-ase.

The preferred oven described above with reference to the accompanying drawings is in three chambers or areas divided, but can also be two, four, five or more Have areas or zones. The number and distribution the gas burner and the injection pipes for the forced convection along the tunnel above or Below the conveying surface can also depending on the particular purpose of the furnace and the temperature requirements with regard to the upper or Bottom of the product to be baked can be selected.

The length of the entry chamber is generally -304.80-365.76 cm, while the remainder of the furnace is divided into essentially equal zones.

The burner output is preferably calculated on the basis of the maximum requirements, the burners being adjustable to 30% of their maximum output by means of a valve. To make a versatile stove, the burners should preferably be billed at $ 15 'allowance. ■ ·

Claims

909812/0144

■, ■ '. ORIGINAL INSPECTED '

Claims (1)

_ 9 - Claims 1. Process for the production of baked items or baked goods, the products to be baked through a tunnel kiln which has a number of successive zones in which the products are heated, characterized in that the first zone is indirectly heated by the combustion of fuel gas, whereupon the hot combustion gases generated in the process are immediately transferred to at least one of the subsequent zones are introduced and, although in contact with the products transported through this zone » 2. The method according to claim 1, characterized in that the transported through the subsequent zones Products are heated by direct contact with hot combustion gases while the products are being processed at the same time against direct irradiation from the flames the gas burner must be protected. 5. Oven with a long tunnel that comes from an entry chamber and at least one further chamber which is in communication with the entry chamber, wherein the furnace has a heating device for the further chamber $ 09812/0144 BATH ORIGINAL ■ Chamber "or the other chambers and an institution for the forward movement of the products through the " Having tunnel, characterized by a heating jacket (22) for the entry chamber (2) for indirect heating of the entry chamber with hot water - combustion gas from the combustion of fuel gas, and duroh a fan (32) for the extraction of combustion gases from the heating jacket (22) and for the immediate, Introduction of these gases into the further chamber or the further chambers (4,6). 4. Oven according to claim 3, characterized in that the Device for heating the further chamber or chambers (4,6) consists of gas burners (24, 26) which in the further chamber or in the further chambers are arranged to heat the objects moved through the chambers by direct contact with hot combustion gases from the combustion of fuel gas, a device or a kitigel (40) for peeling off -of combustion gases from the gas burners and for direct guidance of these gases into the heating jacket (22) the inlet chamber (2) is provided. · 5 »Furnace according to Claim 3 or 4, characterized in that that the device for heating the further chamber or chambers (4, 6) composed of gas burners (24, 26) arranged therein, with one or more shields 309812/0144 (28) (28) in the chamber or chambers (4, 6) for
Seiratz of the products advanced by these
are provided against direct irradiation from the gas burners, while at the same time a substantially free flow of the combustion gases in contact with the products is guaranteed. 909812 / 0U4 OTUQlNM.