RU2121274C1 - Apparatus for baking hollow products (versions) - Google Patents

Abstract

FIELD: baking industry, in particular, production of wafer cups or horns. SUBSTANCE: apparatus has frame with expanding shell mold provided with punch block and split die. Lock ring with steam discharge channels is fixed on shank part of each punch. According to one version, heating members are positioned within body of each punch, and according to other version, heating members having design value of electrical resistance are positioned within shell mold body. EFFECT: reduced power consumption, simplified production and operation. 3 cl, 4 dwg

Description

 The invention relates to equipment for baking and can be used in the confectionery and baking fields of the food industry, namely for baking hollow products - waffle cups and horns.

 Well-known devices for baking hollow products, which contain heating chambers, a conveyor with molds fixed on it, a dispenser for spilling dough, forming bodies and a mechanism for sampling finished products. An example is a device for the manufacture of wafer cups described in USSR author's certificate N 303040, MKI A 21 B 5/02, 1971, containing a forming body made in the form of a cone-shaped core, an electric current is supplied to its spiral, and primary heat treatment with the formation of a hard shell is carried out during the formation, and the finishing of the product to the condition is carried out in the heating chamber, which leads to an increase in the cycle time required for the manufacture of a unit of the product, and therefore an increase in energy consumption. In addition, the long stay of the product in the heat chamber, due to the design of the installation, worsens the quality of the wafer cups, causing them to dry out, deform, which ultimately reduces the percentage of suitable products. Additional energy consumption is required to restore the working temperature of the mold, since they are outside the heating zone for half a turn time of the conveyor. The manufacture of a ceramic mold with a mechanism for ejecting finished products complicates the manufacture and operation of the device.

 A device for baking wafer cups is described in USSR author's certificate N 1666017, MKI A 21 B 5/02, 1991, containing a frame with a drive and rotor mounted on it, on which detachable dies with punches, a dispenser and a mechanism for selecting finished products.

 Heating elements mounted on a rack rigidly connected to the frame, located on the inner and outer sides of the matrix path, cause heat transfer when baking products from split matrixes through the dough to the punch. When pouring dough, which has a technology temperature below room temperature, detachable dies with punches lose some of the available heat. And if the heat loss of detachable dies is compensated by heating elements, then punches that do not have such compensation lose their working temperature after a certain time, which takes time and energy to recover.

 Closest to the invention is a semi-automatic device for baking hollow products, containing a frame with a detachable mold, a dispenser, heating elements, a control unit with separate temperature control, a punches unit and a mold with molds (Installation for baking wafer molds for ice cream E50 form “HAAS” ", exhibited at the exhibition" INPRODTORGMASH-95 ", October 2 - 7, 1995, Moscow.

 The disadvantage of this device is the increased energy consumption, since the thermal energy released from the heating elements, made in the form of flat wide plates, pressed one surface to the plate on which the punches are fixed, is spent on heating the plate, which in turn transfers thermal energy to punches, and the thermal energy emitted from their other surface is dissipated in the surrounding space, increasing energy loss. In addition, the development of the edge of the annular protrusion of the punches, necessary for tight locking of the matrix during baking, leads to the need to replace the costly in the manufacture of punches completely and the cost of repair and restoration work during operation.

 The objective of the invention is to provide a compact reliable, easy to use and economical device for baking hollow products with high consumer quality.

 The problem is solved in that in the device for baking hollow products containing a frame with a detachable mold, a dispenser, heating elements, a control unit, heating elements are placed coaxially to the baked products in the body of each fixed punch, on the tail of which there is a locking ring with steam channels. In another embodiment, heating elements with a calculated value of electrical resistance are placed with the body of the mold and are locally combined in groups, providing a uniform distribution of the temperature field. A locking ring is also installed on the tail of each fixed punch in the steam outlet channels.

 The technical result of the claimed invention is to create an economical, reliable device due to the proximity of the heating elements to the sintering surface and create a gentle mode during their operation due to local grouping, which reduces energy consumption and improves the reliability of the device. The installation of punches with a removable locking ring with steam outlet channels makes it possible to replace it when the edge of the ring is worn without changing the punch, which reduces the cost of repair work, and the possibility of moving the ring relative to the axis of the punch allows you to easily align the mold with its assembly without additional devices. The installation of heating elements with a calculated value of electrical resistance in accordance with their location in the mold allows for a uniform distribution of the temperature field in the baking zone, guaranteeing the quality of product manufacturing.

 In FIG. 1 shows a general view of a device for baking hollow articles; in FIG. 2 and FIG. 3 shows a sectional diagram of a block of punches and a split matrix; in FIG. 4 presents a) a graph of the temperature distribution; b, c) connection diagrams of the resistances of the heating elements of the block of punches and matrix.

 A device for baking hollow products (Fig. 1) contains a frame 1 with a mold installed on it, which contains a block of 2 punches and a detachable matrix 3, connected by a lifting and lowering mechanism 4, for example, a crank mechanism with a counterweight 5 and a pneumatic drive 6 The detachable matrix 3, structurally made of sectional elements 7, is connected by a sliding mechanism 8 through a system of levers with a pneumatic drive 9. The electrical control unit 10 (not shown in FIG.) Contains visual observation and monitoring devices for t temperature, baking time, is designed to measure, display and maintain a constant temperature of the working surfaces of the block of 2 punches and detachable matrix 3, as well as control the time of baking and issuing a control signal to lift the block of 2 punches after baking. Under the detachable matrix 3, a container is installed (not shown in Fig.), Which serves to receive the finished product.

 Block 2 of the punches (Fig. 2, 3) contains a protective casing 11 and the plate 12 with the punches 13 mounted on it, on the shanks of which the locking rings 14 with steam outlet channels are pre-installed. The punches are attached to the plate with nuts 15. In the body of each of the punches having corresponding cavities, heating elements 16 are installed, the electrical resistances of which are selected depending on the place of their installation on the plate to obtain a uniform temperature field.

где
λ - коэффициент теплопроводности;
T - температура пресс-формы;

нормальная производная;
Γ - внешняя поверхность пресс-формы;
α - коэффициент теплоотдачи;
T_ср - температура среды.When calculating the electrical resistances of the heating elements by 16 authors, it was assumed that the mold is convectively cooled from all sides and then a boundary condition of the third kind is satisfied at the external boundaries:

Where
λ is the coefficient of thermal conductivity;
T is the temperature of the mold;

normal derivative;
Γ is the outer surface of the mold;
α is the heat transfer coefficient;
T _cf is the temperature of the medium.

 Since the temperature of the mold should be the same, and fall closer to the surface temperature closer to the boundary, it is possible to reduce the three-dimensional Poisson heat equation to a one-dimensional problem.

где
Q - неизвестное распределение интенсивности теплового источника - нагревательного элемента 16;

коэффициент теплоотдачи,
где
S - площадь верхней или нижней области пресс-формы;
V - объем области пресс-формы.Then we have:

Where
Q is the unknown intensity distribution of the heat source - the heating element 16;

heat transfer coefficient,
Where
S is the area of the upper or lower region of the mold;
V is the volume of the mold area.

где
b - половина ширины области распределения температуры;
h - среднее значение температуры.The temperature distribution required for the mold shown in FIG. 4a is described fairly well by formula (3):

Where
b is half the width of the temperature distribution region;
h is the average temperature.

Можно пренебречь величиной

ввиду ее малости и и упростить выражение (4):

Используя выражение (5), определяем P_пер - мощности нагревателей 16, расположенных в середине пресс-формы:

где
d - расстояние между нагревателями;
δ - толщина матрицы;
x - место установки нагревателя.Substituting (3) in (2) we get:

You can neglect the value

due to its smallness and to simplify the expression (4):

Using expression (5), we determine P _per - power heaters 16 located in the middle of the mold:

Where
d is the distance between the heaters;
δ is the thickness of the matrix;
x - place of installation of the heater.

где
Δ - расстояние от нагревателя до края пресс-формы. Выражения (6) и (7) позволили рассчитать величины сопротивлений нагревательных элементов 16 блока 2 пуансонов и матрицы 3 и объединить их в локальные группы (фиг. 4,б, в), обеспечивающие заданное распределение (фиг. 4, а) температурного поля.Using expression (5), we determine P _per - power of the heaters 16 located on the border of the mold;

Where
Δ is the distance from the heater to the edge of the mold. Expressions (6) and (7) allowed us to calculate the resistance values of the heating elements 16 of the block 2 of the punches and matrix 3 and combine them into local groups (Fig. 4, b, c), providing a given distribution (Fig. 4, a) of the temperature field.

 The device operates as follows.

After supplying compressed air to the inlet and turning on the Start button on the control unit 10, the technological baking mode (180-200) is set ^{. O} C is the temperature of the working surfaces of the mold and the baking time (100-120) sec. After reaching the set temperature (after about 25-30 minutes) by pressing the “Punch up” button on the control unit 10, the mold is opened and the die 3 from the dispenser (not shown in FIG.) Is filled with dough. Then, from the control unit 10, the button "Lowering the punches", electrically connected to the distributor, controlled by the pneumatic actuator 6 and the lowering mechanism 4, the block 2 of the punches returns to the matrix 3, tightly closing the locking rings 15 of the form of the matrix 3. After the baking time, the control unit 10 gives a signal on the rise of the block 2 punches and the mold is automatically opened. After removing the burr (test residues) from the surface of the matrix 3, its sections 7 are moved apart by pressing the "Open matrix" button located on the control unit 10 and connected to the electric air distributor of the sliding mechanism 8. Using special ejector grooves, finished products are automatically released and fall into the finished container products that are installed under the matrix 3. The freed matrix 3 is closed by pressing the "Matrix close" button on the control unit 10 and the baking cycle is repeated. The placement of the buttons on the control unit 10 corresponds to the technological sequence of baking products, and the electrical circuit of the control unit 10 blocks the possibility of erroneous inclusions. The mechanism for raising and lowering the block 2 punches, the opening and closing mechanism 8, matrix 3 have duplicate pneumatic actuators 6 and 9 levers, allowing you to use this device in manual mode.

Claims (2)

 1. A device for baking hollow products, containing a frame with a detachable mold, a dispenser, heating elements, a control unit, characterized in that the heating elements are placed coaxially with the baked products in the body of each fixed punch, on the tail of which there is a locking ring with steam channels.  2. A device for baking hollow products, containing a frame with a detachable mold, a dispenser, heating elements, a control unit, characterized in that a locking ring with steam outlet channels is installed on the tail of each fixed punch, and heating elements with a calculated value of electrical resistance are placed in the body of the mold and are locally combined in groups, providing a uniform distribution of the temperature field.

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