RU172962U1 - TANDYIR FURNACE - Google Patents

Abstract

The utility model relates to the field of manufacturing portable industrial tandoor ovens for cooking, containing an inner capsule, coated on the outside with a layer of thermal insulation and enclosed in an outer capsule, which together form a three-layer capsule. The finished three-layer capsule is placed in metal forging, inside, at the bottom of the three-layer capsule, a refractory brick is laid, over which the heating element is located, and a protective grill is installed above the heating element. In this case, the inner capsule and the outer capsule are made manually of chamotte clay and, after drying, are fired in an industrial furnace for 24 hours at a temperature of 1000 ° C. The proposed tandoor allows to increase the mechanical strength of the structure and increase the service life.

Description

The utility model relates to the manufacture of industrial tandoor ovens for cooking.

State of the art

The tandoor oven (tandoor) is a roasting oven, a barbecue of a special spherical or pitcher-like appearance for cooking a variety of foods among the peoples of Asia. Distributed in the countries of Asia Minor, the Maghreb, Spain, Latin America, Armenia, Kyrgyzstan, northwest China (East Turkestan), in the south of Russia, Crimea, Tajikistan, Turkmenistan, India, Uzbekistan, Japan, Africa, among the peoples of the Balkans. Tandoor is traditionally an indispensable attribute of the courtyard of many southern peoples. It is characterized by great heat capacity and economy in fuel consumption (firewood), since the tandoor comes from places where there has never been an abundance of wood. It can be both stationary and portable.

Tandoor is a ceramic hemisphere with a volume of 0.25 to 1 cubic meter. m. with a round opening in the wall or top (with a diameter of approx. from 0.5 to 0.7 m). Traditionally, it is placed in the courtyard on an earthenware platform with its throat up (vertical axis) or horizontal axis (the throat is looking at the horizon). Vertical ones are usually used for baking samsa, bread and even barbecue, and horizontal ones only for baking bread. The walls are externally lined with crude clay bricks. This is done to increase the heat capacity of the furnace. When used, the tandoor is hotly heated by coal, firewood or brushwood. The laying of firewood, the extraction of ash and the planting of bread in the tandoor is done through the same hole. After the tandoor has warmed up enough, the inner walls of the tandoor are quickly wiped from a burning coating. After that, they are sprayed with water and then stick products intended for baking. They reach readiness due to the heat accumulated in the thick walls of the tandoor. After that, usually with the help of a special bucket and a hook with long handles, the products are removed from the tandoor.

Tandoor can be divided into mobile and stationary. Mobile tandoor, unlike stationary ones, after their manufacture must be transported or carried using special equipment (for example, a crane and a truck) or manually. Stationary tandoor are made (constructed) at the place of operation and cannot be moved without partial destruction or disassembly.

Modern mobile or home (household) tandoor made of fireclay clay. The wall thickness is on average 3-7 cm. Modern portable tandoor in shape resembles a vase with a two-level lid and, basically, have metal forged handles. The cover of modern portable tandoor contains a device for the vertical arrangement of skewers. In the lower part there is a blower for coal extraction and kindling of the tandoor. Such tandoori consist of a single-layer capsule, which is placed in the forging and equipped with handles. They are only wood, use them for cooking meat, poultry, etc. in small portions.

There are also stationary production tandoor for cafes and restaurants. Their manufacturers insulate the outside with insulation material for a longer preservation of the temperature inside the tandoor. The technology for the production of industrial tandoor is very different from the technology for the production of household tandoor. The internal capsule of industrial tandoor is molded from clay, after the natural drying of which outside the tandoor is bricked or tiled. Before starting operation, such a tandoor needs to be warmed up strongly to calcine its walls, but even with such annealing, after a year or 3 years, the walls of the tandoor begin to crumble.

From the patent RU 132871 U1, 09/27/2013 a stationary wood tandoor is known made in the form of a refractory bowl placed in a multilayer heat-insulating casing. The heat-insulating casing consists of a steel cup with a wooden lining inside which a heat-insulating material is poured, consisting of a mixture of sand and fireclay clay.

Such an oven, after assembly, is also not transportable. A single-layer refractory bowl without metal forging has insufficient strength.

The closest in technical essence is the mobile coal fuel tandoor known from the patent CN 204218726 U, 03/25/2015 made in the form of a bowl surrounded by a heat insulator mounted on a frame with wheels for movement.

The disadvantages of such a tandoor furnace are the design complexity (consists of many parts), insufficient strength (only the bottom is made of strong metal), low productivity and profitability (heated by coal).

Disclosure of invention

Thus, there is a need to increase strength, increase the service life, productivity and efficiency of industrial tandoor furnaces, as well as improve the safety of their operation.

The proposed tandoor furnace contains a three-layer capsule, consisting of an inner capsule, coated on the outside with a layer of heat-insulating material, which is enclosed in an outer capsule, the three-layer capsule being placed in metal forging, and a refractory brick is placed inside the three-layer capsule at the bottom, over which the heating element is located, and a protective grill is installed above the heating element, the inner capsule and the outer capsule made of chamotte fired clay.

According to the utility model:

- the inner capsule, the layer of thermal insulation and the outer capsule have a thickness of 5-7 mm;

- wheels are installed below metal forging;

- the heater is a nichrome spiral.

The technical result of the proposed mobile tandoor furnace is to increase the mechanical strength of the structure and increase the service life.

Brief Description of the Drawings

FIG. 1 - tandoor oven.

The implementation of the invention

The proposed tandoor furnace consists of three layers enclosed in metal forging (Fig. 1). The inner capsule (1) is made of chamotte clay (mainly by hand), the wall thickness of the capsule is 5-7 cm. Outside, the inner capsule is covered with a layer of heat-insulating material (2) 5-7 cm thick. The layer of heat-insulating material (2) is enclosed in an external capsule (3), which is also molded mainly by hand from fireclay clay, the wall thickness of this capsule is 5-7 cm. The three-layer capsule is placed in metal forging (4) around the perimeter of the whole product, which serves as a stiffening frame, makes the product resistant to transportation, manual ultrasonic inspection during impacts etc. Wheels (8) can be welded to metal forging, which makes the tandoor mobile. Refractory brick (5) is laid at the bottom inside the three-layer capsule to isolate the heating element (6), which is a nichrome spiral. A protective grill (7) is installed above the heating element, which protects the baker from contact with the heating element.

To increase mechanical strength and durability in the manufacture of tandoor, both the inner (1) and outer (3) capsules, molded manually of chamotte clay, after drying, are fired in an industrial furnace for 24 hours at a temperature of 1000 ° C.

The firing of the inner capsule (1) also improves the quality of the products baked in such a tandoor. After such firing, the walls of the tandoor acquire the properties of ceramics and do not crumble, and the baking is not contaminated with clay particles. The life of the proposed tandoor, with proper operation, is practically unlimited.

With simple heating of the tandoor, the maximum heating temperature reaches only 400 ° C, and the effect of converting clay into ceramics is not achieved. At the same time, the walls crumble over time. The life of such tandoor is about 3 years.

The firing of the outer capsule (3) makes the tandoor durable and resistant to increased mechanical stresses arising during long-term transportation. Such a tandoor is practically not at risk of mechanical damage.

The finished three-layer capsule of the industrial tandoor is in metal forging. Thanks to this solution, the proposed tandoor gains even greater strength and resistance to long-term increased loads.

In addition, the entire design of the tandoor, weighing from 450 to 600 kg and having dimensions of 120 × 90 cm, can be mounted on 4 wheels, which are attached from below to metal forging. This allows you to simplify the movement of the furnace over short distances, for example, inside the production room.

Thanks to the proposed multilayer construction with a heat-insulating layer and manufacturing technology, the heat capacity of the tandoor furnace also increases, that is, the proposed tandoor quickly heats up and cools for a long time. This reduces the baking time of products and, therefore, increase productivity. For example, a cake is baked in the proposed tandoor for 3 minutes, and in known tandoor - 7-10 minutes.

In addition, due to this design, the proposed tandoor furnace is not hot outside. The baker can lean on a heated tandoor without discomfort. This simplifies operation and increases operational safety.

Claims (4)

1. A tandoor oven containing a three-layer capsule, consisting of an inner capsule, coated on the outside with a layer of heat-insulating material, which is enclosed in an outer capsule, the three-layer capsule being placed in metal forging, while a fire brick is placed inside the three-layer capsule at the bottom, over which a heating brick is located element, and a protective grill is installed above the heating element, the inner capsule and the outer capsule made of fireclay burnt clay. 2. The tandoor furnace according to claim 1, characterized in that the inner capsule, the layer of thermal insulation and the outer capsule have a thickness of 5-7 mm. 3. The tandoor furnace according to claim 1, characterized in that the wheels are mounted below the metal forging. 4. The tandoor furnace according to claim 1, characterized in that the heater is a nichrome spiral.

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