A microwave and gas mixed heating roller kiln

Abstract

The present invention discloses a microwave and gas mixed heating roller kiln, the roller kiln body of which includes a first heating section and a second heating section connected in sequence; wherein a gas heating device is arranged in the first heating section, and a microwave heating device is arranged in the second heating section. The microwave and gas mixed heating roller kiln of the present invention is provided with a gas heating device in the first heating section and a microwave heating device in the second heating section; when the product passes through the first heating section, the outer surface of the product is heated by hot air in the first heating section to increase the temperature, and then the product passes through the second heating section, and the microwave emitted by the microwave heating device causes the interior of the product to increase the temperature rapidly; by combining the two methods of gas heating and microwave heating, the advantages of low unit calorific value cost of gas and strong microwave penetration are retained, and the disadvantages of each are relatively overcome, thereby greatly shortening the firing cycle of the product and further increasing the output per unit time.

Description

Technical Field

[0001] The invention relates to the technical field of heating equipment, in particular to a microwave and gas mixed heating roller kiln. Background Art

[0002] Roller kiln is mainly used for firing ceramic products such as tiles, exterior wall tiles, interior wall tiles and floor tiles. Roller kiln uses rotating rollers as a carrier for the green body. The ceramic products are placed on many closely spaced rollers. The rotation of the rollers transfers the ceramics from the head of the kiln to the tail of the kiln, so it is called a roller kiln.

[0003] When heating products, traditional gas roller kilns use gas to heat the ambient air and then the ambient air heats the products. During the heating process, the product surface is in direct contact with the hot air, and the heat inside the product is all conducted through the product surface. Therefore, the temperature inside the product rises much slower than the product surface.

[0004] When heating large and thick products, or when the thermal conductivity of the heated products is poor, it takes a long time for the internal temperature of the product to rise to the required set temperature, thereby extending the product firing cycle time and reducing output. Summary of the invention

[0005] The object of the present invention is to provide a microwave and gas mixed heating roller kiln, which can further shorten the firing cycle of the product and improve the output even when heating products with large volume and thickness or when the thermal conductivity of the heated products is poor.

[0006] In order to achieve the above object, the technical solution of the present invention is:

[0007] A microwave and gas mixed heating roller kiln, comprising:

[0008] Roller kiln body;

[0009] The roller kiln body comprises a first heating section and a second heating section connected in sequence;

[0010] Wherein, a gas heating device is provided in the first heating section, and a microwave heating device is provided in the second heating section.

[0011] The microwave and gas mixed heating roller kiln of the present invention is achieved by dividing the heating section in the roller kiln body into a first heating section and a second heating section connected in sequence, and arranging a gas heating device in the first heating section and a microwave heating device in the second heating section; when the product enters the roller kiln body, it first passes through the first heating section, and the air heated by the gas heating device in the first heating section heats up the outer surface of the product, and then the product passes through the second heating section, and the microwaves emitted by the microwave heating device heat up the inside of the product quickly. By combining gas heating and microwave heating, the present invention not only retains the advantages of low unit calorific value cost of gas and strong microwave penetration, but also relatively overcomes the disadvantages of each, thereby greatly shortening the firing cycle of the product and further increasing the output per unit time.

[0012] Furthermore, the distances from both ends of the second heating section to the microwave heating device are respectively greater than the distances required for the microwaves emitted by the microwave heating device to attenuate to a safe value.

[0013] The present invention ensures that the distances from both ends of the second heating section to the microwave heating device are greater than the distance required for the microwaves emitted by the microwave heating device to attenuate to a safe value, thereby eliminating the need to set a tent for shielding microwaves between the first and second heating sections and ensuring the safety of operators.

[0014] Furthermore, the inner wall of the second heating section is provided with microwave shielding material.

[0015] Furthermore, the microwave and gas mixed heating roller kiln also includes a flue gas waste heat recovery device;

[0016] The flue gas waste heat recovery device includes a first air duct connected to the first heating section and a fan for drawing the flue gas from the first heating section into the first air duct.

[0017] Furthermore, the first air duct is connected to the front end of the first heating section, and is used to guide the smoke in the first heating section to flow in a direction away from the second heating section.

[0018] The present invention connects the first air duct to the front end of the first heating section so that the smoke in the first heating section flows toward the front end of the first heating section, that is, away from the second heating section, thereby preventing the smoke generated by gas heating from excessively flowing into the second heating section and causing damage to the microwave heating device.

[0019] Furthermore, the roller kiln body also includes a heat preservation section, and a gas heating device is provided in the heat preservation section;

[0020] The first heating section, the second heating section and the heat preservation section are connected in sequence.

[0021] Furthermore, the flue gas waste heat recovery device also includes a second air duct having two ends respectively connected to the insulation section and the fan;

[0022] Wherein, the second air duct is connected to the rear end of the insulation section, and is used to guide the smoke in the insulation section to flow in a direction away from the second heating section.

[0023] As a specific implementation, the microwave and gas mixed heating roller kiln also includes a combustion-supporting air device;

[0024] The combustion-supporting air device is connected to the flue gas waste heat recovery system via a heat exchanger, and the heat in the flue gas waste heat recovery system is used to recover the waste heat of the combustion-supporting air device via the heat exchanger.

[0025] As a specific implementation, the roller kiln body further includes a cooling section, the cooling section is connected to a cooling air device, the cooling air device is used to generate low-temperature or normal-temperature air flow and blow it into the cooling section;

[0026] The first heating section, the second heating section, the heat preservation section and the cooling section are connected in sequence.

[0027] As a specific implementation, the microwave and gas mixed heating roller kiln also includes a roller conveying device arranged in the roller kiln body.

[0028] For better understanding and implementation, the present invention is described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 2 is a schematic diagram of the front structure of a microwave and gas mixed heating roller kiln according to an embodiment of the present invention;

[0030] Figure 2 It is a cross-sectional view of the second heating section of the microwave and gas mixed heating roller kiln according to an embodiment of the present invention;

[0031] Figure 3 It is a schematic diagram of the rear structure of the microwave and gas mixed heating roller kiln according to an embodiment of the present invention. DETAILED DESCRIPTION

[0032] In order to better illustrate the present invention, the present invention is further described in detail below with reference to the accompanying drawings.

[0033] like Figure 1 As shown, a microwave and gas mixed heating roller kiln comprises:

[0034] Roller kiln body 100;

[0035] The roller kiln body 100 includes a first heating section 110 and a second heating section 120 which are connected in sequence;

[0036] The first heating section 110 is provided with a gas heating device, and the second heating section 120 is provided with a microwave heating device.

[0037] It should be noted that, without affecting understanding, the specific structural schematic diagrams of the gas heating device and the microwave heating device are not given in the drawings.

[0038] Specifically, the microwave and gas mixed heating roller kiln further includes a roller conveying device 200 disposed in the roller kiln body 100 .

[0039] The structure of the gas heating device is basically the same as the prior art. Its combustion chamber is located below the roller conveyor device. Compressed air is used to atomize natural gas, heavy oil, diesel and other fuels for combustion to generate high temperature, thereby heating the air in the first heating section. There is refractory material between the combustion chamber and the roller, so the flame does not directly contact the product being burned.

[0040] like Figure 2 As shown, the microwave heating device includes a microwave source assembly 300; preferably, the microwave source assembly 300 is arranged on the top of the second heating section 120, and emits microwaves from top to bottom to the product passing through the second heating section 120.

[0041] Preferably, the inner wall of the second heating section 120 is provided with a microwave shielding material 400 to prevent microwaves from leaking from the side walls and the top of the roller kiln body.

[0042] Preferably, both ends of each roller of the roller conveyor device at the bottom of the second heating section are enclosed in a metal cover to prevent microwaves from leaking out of the roller conveyor device.

[0043] The microwave and gas mixed heating roller kiln of this embodiment is formed by dividing the heating section in the roller kiln body into the first and second heating sections connected in sequence, and setting a gas heating device in the first heating section and a microwave heating device in the second heating section; when the product enters the roller kiln body, it first passes through the first heating section, and the air heated by the gas heating device in the first heating section heats up the outer surface of the product, and then the product passes through the second heating section, and the microwaves emitted by the microwave heating device heat up the inside of the product quickly. By combining gas heating and microwave heating, the present invention not only retains the advantages of low unit calorific value cost of gas and strong microwave penetration, but also relatively overcomes the disadvantages of each, thereby greatly shortening the firing cycle of the product and further increasing the output per unit time.

[0044] Preferably, the distances from both ends of the second heating section 120 to the microwave heating device are greater than the distances required for the microwaves emitted by the microwave heating device to attenuate to a safe value.

[0045] In this embodiment, the distances from both ends of the second heating section to the microwave heating device are made greater than the distance required for the microwaves emitted by the microwave heating device to attenuate to a safe value, so that there is no need to set up a tent for shielding microwaves between the first and second heating sections, and the safety of the operator can be guaranteed.

[0046] Since no tent is required between the first and second heating sections, the temperature difference between the first and second heating sections will not be too large. Therefore, after the product enters the second heating section from the first heating section, its outer surface will not be cooled by the air in the second heating section.

[0047] Preferably, the microwave and gas mixed heating roller kiln further includes a flue gas waste heat recovery device 500;

[0048] The flue gas waste heat recovery device 500 includes a first air duct 510 connected to the first heating section 110 and a fan 530 for drawing the flue gas of the first heating section 110 into the first air duct 510 .

[0049] In this embodiment, the first air duct is connected to the front end of the first heating section so that the smoke in the first heating section flows toward the front end of the first heating section, that is, away from the second heating section, thereby preventing the smoke generated by gas heating from excessively flowing into the second heating section and causing damage to the microwave heating device.

[0050] Preferably, the roller kiln body 100 further includes a heat preservation section 130, and a gas heating device is provided in the heat preservation section 130;

[0051] The first heating section 110, the second heating section 120 and the heat preservation section 130 are connected in sequence.

[0052] It should be noted that the setting of the heat preservation section is the same as that of the first heating section, the difference being that the heating power of its gas heating device is slightly lower than the power of the gas heating device in the first heating section.

[0053] Preferably, the flue gas waste heat recovery device 500 further includes a second air duct 520 having two ends respectively connected to the heat preservation section 130 and the fan 530;

[0054] The second air duct 520 is connected to the rear end of the heat preservation section 130 , and is used to guide the smoke in the heat preservation section 130 to flow in a direction away from the second heating section 120 .

[0055] Specifically, the microwave and gas mixed heating roller kiln further includes a combustion-supporting air device 600, which is used to provide combustion-supporting air to the gas heating device at the bottom of the first heating section 110 and the heat preservation section 130;

[0056] The combustion-supporting air device 600 is connected to the flue gas waste heat recovery device 500 via a heat exchanger 700, and the heat in the flue gas waste heat recovery system is used to recover the waste heat of the combustion-supporting air device through the heat exchanger.

[0057] Specifically, the roller kiln body further includes a cooling section, and the cooling section is connected to a cooling air device 600, and the cooling air device 600 is used to generate low-temperature or normal-temperature air flow and blow it into the cooling section;

[0058] The first heating section 110, the second heating section 120, the heat preservation section 130 and the cooling section are connected in sequence.

[0059] Specifically, the cooling section includes a rapid cooling section 140 and a slow cooling section 150. Both the rapid cooling section 140 and the slow cooling section 150 are provided with cold air by a cooling air device 800. The difference is that the wind speed at the air outlet of the cooling air device in the rapid cooling section is different from that in the slow cooling section, or the temperature of the cold air provided to the rapid cooling section and the slow cooling section is different.

[0060] It should be noted that, in this embodiment, the first heating section 110, the second heating section 120, the insulation section 130, the rapid cooling section 140 and the slow cooling section 150 are connected by conductive sealing rings; in addition, conductive silicone, conductive graphite packing and other objects can also be used to connect the sections.

[0061] In addition, those skilled in the art may combine and associate different embodiments or examples and features of different embodiments or examples described in this specification without mutual contradiction.

[0062] In the description of the present invention, it is necessary to understand that the terms "vertical", "lateral", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the protection content of the present invention.

[0063] If the words "first", "second", etc. are used in this document to limit components, those skilled in the art should know that the use of "first" and "second" is only to facilitate the description of the present invention and simplify the description. Unless otherwise stated, the above words have no special meaning.

[0064] The present invention is not limited to the above-mentioned embodiments. If various changes or modifications to the present invention do not depart from the spirit and scope of the present invention, and if these changes and modifications fall within the scope of the claims and equivalent technologies of the present invention, the present invention is also intended to include these changes and modifications.

Claims

1. A microwave and gas mixed heating roller kiln, characterized in that: include: Roller kiln body; The roller kiln body comprises a first heating section and a second heating section connected in sequence; Wherein, a gas heating device is provided in the first heating section, and a microwave heating device is provided in the second heating section; The distances from both ends of the second heating section to the microwave heating device are greater than the distance required for the microwaves emitted by the microwave heating device to attenuate to a safe value; Flue gas waste heat recovery device; The flue gas waste heat recovery device comprises a first air duct connected to the first heating section, and a fan for drawing the flue gas from the first heating section to the first air duct; The first air duct is connected to the front end of the first heating section, and is used to guide the smoke in the first heating section to flow in a direction away from the second heating section.

2. The microwave and gas mixed heating roller kiln according to claim 1 is characterized in that: The inner wall of the second heating section is provided with microwave shielding material.

3. The microwave and gas mixed heating roller kiln according to claim 1 is characterized in that: The roller kiln body also includes a heat preservation section, in which a gas heating device is provided; The first heating section, the second heating section and the heat preservation section are connected in sequence.

4. The microwave and gas mixed heating roller kiln according to claim 3 is characterized in that: The flue gas waste heat recovery device also includes a second air duct connected to the insulation section and the fan at both ends respectively; Wherein, the second air duct is connected to the rear end of the insulation section, and is used to guide the smoke in the insulation section to flow in a direction away from the second heating section.

5. The microwave and gas mixed heating roller kiln according to claim 1, characterized in that: Also includes: Combustion air device; A heat exchanger is connected between the combustion-supporting air device and the flue gas waste heat recovery device.

6. The microwave and gas mixed heating roller kiln according to claim 1, characterized in that: include: The roller kiln body also includes a cooling section, the cooling section is connected to a cooling air device, the cooling air device is used to generate low-temperature or normal-temperature air flow and blow it into the cooling section; The first heating section, the second heating section, the heat preservation section and the cooling section are connected in sequence.

7. The microwave and gas mixed heating roller kiln according to any one of claims 1 to 6, characterized in that: Also includes: A roller conveying device is arranged in the roller kiln body.

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