A secondary heat exchange tunnel furnace

Abstract

The present invention discloses a secondary heat exchange tunnel furnace, comprising a combustion chamber containing air to be heated; a burner connected to the combustion chamber, the burner being suitable for heating the air to be heated in the combustion chamber; a first heat exchange chamber, a first heat exchange tube connected to the combustion chamber being installed in the first heat exchange chamber, the first heat exchange tube being suitable for heating the air in the first heat exchange chamber; a second heat exchange chamber, a second heat exchange tube connected to the first heat exchange tube being installed in the second heat exchange chamber, the second heat exchange tube being suitable for heating the air in the second heat exchange chamber; an exhaust pipe connected to the second heat exchange tube, so as to be suitable for the gas heated by the combustion chamber to flow through the first heat exchange tube and the second heat exchange tube and then be discharged; the secondary heat exchange tunnel furnace has a high fuel utilization rate and can prevent combustion exhaust gas from directly contacting food and causing food contamination.

Description

Technical Field

[0001] The invention relates to the technical field of tunnel furnaces, and in particular to a secondary heat exchange type tunnel furnace. Background Art

[0002] Tunnel furnace (food processing type) is a tunnel-type mechanical equipment that completes food baking through heat conduction, convection and radiation. The furnace body of the oven is generally very long, with a minimum of 6 meters and a length of 60 to 80 meters. The baking chamber is a long and narrow tunnel, with a width of generally 80cm to 140cm. There is a continuously operating conveying system in the tunnel. When the food is baked, the food moves relative to the electric heating element or direct-burning combustion rod through the conveyor chain plate, steel belt or mesh belt. Thus, the work of uniform baking and transportation is completed. Tunnel furnaces are divided into flame tunnel furnaces, flame-proof tunnel furnaces and semi-flame-proof tunnel furnaces according to whether the flame enters the tunnel.

[0003] The flame-muffle tunnel furnace mainly uses the heat generated by the burner to directly enter the furnace in the form of air and act on the product. However, there are the following disadvantages in heating food in this way: first, the combustion exhaust gas directly contacts the food, causing food contamination, especially if the fuel is diesel or liquefied gas; second, the surface color of the product baked by this combustion method is dull and rough; third, during the baking process of the whole furnace, moisture will drip onto the ground in the furnace, because the moisture generated by the combustion directly enters the furnace, and the alternation of hot and cold will produce condensed water. Long-term moisture will corrode and rust the furnace frame structure. The combustion system using indirect hot air can avoid direct contact between combustion exhaust gas and food, causing food contamination, but its combustion efficiency is too low, the fuel utilization rate is only 35-50%, and the structure is simple and the safety is poor. Summary of the invention

[0004] In order to overcome the deficiencies of the prior art, the object of the present invention is to provide a secondary heat exchange tunnel furnace with high fuel utilization rate and the ability to prevent combustion exhaust gas from directly contacting food and causing food contamination.

[0005] The purpose of the present invention is achieved by the following technical solutions:

[0006] A secondary heat exchange tunnel furnace, comprising

[0007] a combustion chamber, containing the air to be heated;

[0008] a burner, connected to the combustion chamber, and adapted to heat the air to be heated in the combustion chamber;

[0009] a first heat exchange chamber, wherein a first heat exchange tube communicating with the combustion chamber is installed in the first heat exchange chamber, and the first heat exchange tube is suitable for heating the air in the first heat exchange chamber;

[0010] a second heat exchange chamber, wherein a second heat exchange tube communicating with the first heat exchange tube is installed in the second heat exchange chamber, and the second heat exchange tube is suitable for heating the air in the second heat exchange chamber;

[0011] an exhaust pipe, connected to the second heat exchange pipe, so that the gas heated by the combustion chamber flows through the first heat exchange pipe and the second heat exchange pipe and then is discharged;

[0012] a first air inlet pipe, disposed on a side of the first heat exchange chamber and communicating with the first heat exchange chamber;

[0013] a circulation fan, installed on the first air inlet pipe, suitable for conveying external air into the first heat exchange chamber through the first air inlet pipe;

[0014] A heating chamber, the heating chamber is used to accommodate items to be heated;

[0015] An air box is installed in the heating chamber and communicated with the first heat exchange chamber. A plurality of exhaust holes are provided on the surface of the air box. The air heated by the first heat exchange chamber enters the heating chamber through the air box and is discharged through the plurality of exhaust holes.

[0016] a circulation pipe, wherein the inlet of the circulation pipe is communicated with the heating chamber, and the outlet of the circulation pipe is communicated with the first air inlet pipe, so that the hot air in the heating chamber flows into the first air inlet pipe and enters the first heat exchange chamber for heating together with the external air;

[0017] The first connecting pipe is connected to the circulation pipe and the second heat exchange chamber respectively, so that the heated air in the second heat exchange chamber enters the wind box through the circulation pipe and the first heat exchange chamber, and is discharged from the heating chamber through the plurality of exhaust holes.

[0018] Furthermore, the secondary heat exchange tunnel furnace also includes an adjustment mechanism, which includes a rotating rod and a baffle. The wind box also includes an adjustment pipe and an upper wind box. The adjustment pipe is arranged at the upper end of the upper wind box. The upper wind box is connected to the first heat exchange chamber through the adjustment pipe. The baffle is arranged in the adjustment pipe. One end of the rotating rod is placed in the adjustment pipe and fixed to the baffle. An air hole for heated air to pass through is formed between the baffle and the inner wall of the adjustment pipe. The rotating rod is suitable for rotating under the action of external force and driving the baffle to rotate together to adjust the size of the air hole.

[0019] Furthermore, the wind box also includes a lower wind box and a second connecting pipe connecting the regulating duct and the lower wind box, the upper wind box is arranged at the upper end of the lower wind box, the exhaust hole is arranged on the opposite sides of the upper wind box and the lower wind box, and a storage space for placing items to be heated is formed between the upper wind box and the lower wind box.

[0020] Furthermore, a plurality of second guide plates are provided at the connection between the lower wind box and the second connecting pipe.

[0021] Furthermore, a plurality of first guide plates are provided at the connection between the upper wind box and the regulating duct, and the first guide plates are suitable for guiding the heated air entering the upper wind box from the regulating duct.

[0022] Furthermore, a plurality of third guide plates are provided at the connection end between the circulation pipe and the heating chamber.

[0023] Furthermore, the secondary heat exchange tunnel furnace also includes a controller, a temperature sensor is provided in the heating chamber, and the controller is electrically connected to the temperature sensor, the burner and the circulating fan.

[0024] Furthermore, the first air inlet pipe is provided with an exhaust port.

[0025] Furthermore, the exhaust pipe is equipped with an exhaust fan.

[0026] Furthermore, a second air inlet pipe is arranged on the side of the second heat exchange chamber to allow external air to enter the second heat exchange chamber.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] The present application arranges a first heat exchange tube connected to the combustion chamber in the first heat exchange chamber, and arranges a second heat exchange tube connected to the first heat exchange tube in the second heat exchange chamber, so that the smoke generated after the combustion of the burner heats the outside air through the first heat exchange tube and the second heat exchange tube, and heats the food in the heating chamber through the outside air, thereby preventing the smoke generated after the combustion of the burner from directly contacting the food in the heating chamber, causing the food to be contaminated and the food surface to be dull and rough in color; at the same time, the use of two heat exchange methods can fully utilize the heat of the smoke generated after the combustion in the combustion chamber, and the heating chamber is connected to the first air intake pipe by a circulation pipe, so that the high-temperature air in the heating chamber can flow back into the first heat exchange chamber through the first air intake pipe for reheating, thereby reducing energy consumption and improving heat utilization. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a structural schematic diagram of a secondary heat exchange tunnel furnace of the present invention;

[0030] Figure 2 A top view of a secondary heat exchange tunnel furnace of the present invention;

[0031] Figure 3 It is a cross-sectional view of a secondary heat exchange tunnel furnace of the present invention;

[0032] Figure 4 It is a structural schematic diagram of a secondary heat exchange tunnel furnace air box of the present invention;

[0033] Figure 5 It is a structural schematic diagram of an upper wind box of a secondary heat exchange tunnel furnace of the present invention.

[0034] Illustration: 10, combustion chamber; 101, burner; 20, first heat exchange chamber; 201, first heat exchange tube; 30, second heat exchange chamber; 301, second heat exchange tube; 302, second air inlet pipe; 40, exhaust pipe; 401, exhaust fan; 50, first air inlet pipe; 501, circulation fan; 502, exhaust port; 60, heating chamber; 601, wind box; 6011, upper wind box; 60111, first guide plate; 6012, lower wind box; 60121, second guide plate; 6013, second connecting pipe; 6014, regulating pipe; 70, circulation pipe; 80, first connecting pipe; 901, rotating rod; 902, baffle. DETAILED DESCRIPTION

[0035] The present invention is further described below in conjunction with the accompanying drawings and specific implementation methods. It should be noted that, under the premise of no conflict, the various embodiments or technical features described below can be arbitrarily combined to form a new embodiment.

[0036] like Figure 1-5 A secondary heat exchange tunnel furnace is shown, wherein a combustion chamber 10 contains air to be heated;

[0037] A burner 101 is connected to the combustion chamber 10, and the burner 101 is suitable for heating the air to be heated in the combustion chamber 10;

[0038] A first heat exchange chamber 20, wherein a first heat exchange pipe 201 communicating with the combustion chamber 10 is installed in the first heat exchange chamber 20, and the first heat exchange pipe 201 is suitable for heating the air in the first heat exchange chamber 20;

[0039] A second heat exchange chamber 30, wherein a second heat exchange tube 301 communicating with the first heat exchange tube 201 is installed in the second heat exchange chamber 30, and the second heat exchange tube 301 is suitable for heating the air in the second heat exchange chamber 30;

[0040] The exhaust pipe 40 is connected to the second heat exchange pipe 301 so that the gas heated by the combustion chamber 10 flows through the first heat exchange pipe 201 and the second heat exchange pipe 301 and then is discharged;

[0041] A first air inlet pipe 50 is disposed on a side of the first heat exchange chamber 20 and communicates with the first heat exchange chamber 20;

[0042] The circulation fan 501 is installed on the first air inlet pipe 50 to transport the external air to the first heat exchange chamber 20 through the first air inlet pipe 50;

[0043] A heating chamber 60, the heating chamber 60 is used to accommodate items to be heated;

[0044] The wind box 601 is installed in the heating chamber 60 and communicated with the first heat exchange chamber 20. A plurality of exhaust holes are provided on the surface of the wind box 601. The air heated by the first heat exchange chamber 20 enters the heating chamber 60 through the wind box 601 and is discharged through the plurality of exhaust holes.

[0045] A circulation pipe 70, the inlet of which is in communication with the heating chamber 60, and the outlet of which is in communication with the first air inlet pipe 50, so that the hot air in the heating chamber 60 flows into the first air inlet pipe 50 and enters the first heat exchange chamber 20 together with the external air to be heated;

[0046] The first connecting pipe 80 is connected to the circulation pipe 70 and the second heat exchange chamber 30 respectively, so that the heated air in the second heat exchange chamber 30 enters the wind box 601 through the circulation pipe 70 and the first heat exchange chamber 20, and is discharged from the heating chamber 60 through multiple exhaust holes.

[0047] During operation, the burner 101 heats the air in the combustion chamber 10 and generates flue gas, and the generated flue gas will flow into the first heat exchange tube 201 to heat the air in the first heat exchange chamber 20, and then the flue gas will flow into the second heat exchange tube 301 through the first heat exchange tube 201 to heat the air in the second heat exchange chamber 30, at this time, the circulating fan 501 transports the outside air and the heated air in the second heat exchange chamber 30 to the first heat exchange chamber 20, and the first heat exchange tube 201 heats the air entering the first heat exchange chamber 20 to form high-temperature hot air, and the generated high-temperature hot air will be transported by the wind box 601 to the heating chamber 60 to heat the food to be heated in the heating chamber 60, at this time, the partially utilized high-temperature hot air will flow into the first air inlet pipe 50 through the circulation pipe 70, and under the action of the circulation fan 501, it will flow back into the first heat exchange chamber 20 for reheating and utilization. In the present application, an air inlet for the outside air to enter is provided on the side of the combustion chamber 10.

[0048] The present application sets a first heat exchange tube 201 connected to the combustion chamber 10 in the first heat exchange chamber 20, and sets a second heat exchange tube 301 connected to the first heat exchange tube 201 in the second heat exchange chamber 30, so that the smoke generated by the burner 101 after combustion heats the outside air through the first heat exchange tube 201 and the second heat exchange tube 301, and heats the food in the heating chamber 60 through the outside air, so as to avoid the smoke generated by the burner 101 after combustion directly contacting the food in the heating chamber 60, resulting in food contamination and dull and rough color on the surface of the food; at the same time, the heat of the smoke generated by the combustion chamber 10 after combustion can be fully utilized by using the double heat exchange method, and the heating chamber 60 is connected to the first air intake pipe 50 by using the circulation pipe 70, so that the high-temperature air in the heating chamber 60 can flow back into the first heat exchange chamber 20 through the first air intake pipe 50 for reheating, so as to reduce energy consumption and improve heat utilization.

[0049] Specifically, the secondary heat exchange tunnel furnace also includes an adjustment mechanism, which includes a rotating rod 901 and a baffle 902. The wind box 601 also includes an adjustment pipe 6014 and an upper wind box 6011. The adjustment pipe 6014 is arranged at the upper end of the upper wind box 6011. The upper wind box 6011 is connected to the first heat exchange chamber 20 through the adjustment pipe 6014. The baffle 902 is arranged in the adjustment pipe 6014. One end of the rotating rod 901 is placed in the adjustment pipe 6014 and is fixedly connected to the baffle 902. A space is formed between the baffle 902 and the inner wall of the adjustment pipe 6014 for heated air to pass through. The rotating rod 901 is suitable for rotating under the action of external force and driving the baffle 902 to rotate together to adjust the size of the air hole. When working, the size of the air hole is adjusted by rotating the rotating rod 901, thereby adjusting the flow rate of hot air entering the regulating pipe 6014 through the air hole, thereby adjusting the temperature in the heating chamber 60 to avoid excessively high or low temperature, which may cause the food in the heating chamber 60 to burn or not be heated and cooked. The hot air flows into the upper air box 6011 after passing through the air hole, and enters the heating chamber 60 through the exhaust hole opened on the surface of the upper air box 6011 to heat the food in the heating chamber 60.

[0050] More specifically, the wind box 601 further comprises a lower wind box 6012 and a second connecting pipe 6013 connecting the regulating pipe 6014 and the lower wind box 6012, the upper wind box 6011 is arranged at the upper end of the lower wind box 6012, the exhaust hole is arranged on the opposite sides of the upper wind box 6011 and the lower wind box 6012, and a receiving space for placing the items to be heated is formed between the upper wind box 6011 and the lower wind box 6012, so as to heat both sides of the food synchronously, so that the food is heated evenly, and the situation that some parts are not cooked while other parts are cooked is avoided. During operation, part of the hot air enters the upper wind box 6011 through the regulating pipe 6014, and enters the heating chamber 60 from the exhaust hole provided on the surface of the upper wind box 6011, and the rest of the hot air enters the lower wind box 6012 through the second connecting pipe 6013, and enters the heating chamber 60 from the exhaust hole provided on the surface of the lower wind box 6012, so as to heat the food from both sides.

[0051] Specifically, a plurality of second guide plates 60121 are provided at the connection between the lower air box 6012 and the second connecting pipe 6013 to uniformly guide the hot air entering from the second connecting pipe 6013 into the lower air box 6012 to avoid insufficient air flow in the exhaust hole.

[0052] A plurality of first guide plates 60111 are provided at the connection between the upper wind box 6011 and the regulating duct 6014. The first guide plates 60111 are suitable for guiding the heated air entering the upper wind box 6011 from the regulating duct 6014, so that the heated air flows evenly into the upper wind box 6011 and is discharged from the exhaust hole, thereby avoiding insufficient air flow in the exhaust hole part, thereby ensuring that the surface of the food is heated evenly during heating.

[0053] A plurality of third guide plates are provided at the connection end between the circulation pipe 70 and the heating chamber 60 to facilitate uniform entry of hot air.

[0054] Specifically, the secondary heat exchange tunnel furnace also includes a controller, a temperature sensor is provided in the heating chamber 60, and the controller is electrically connected to the temperature sensor, the burner 101 and the circulating fan 501. The temperature sensor in this application is a thermocouple temperature sensor, and two are provided corresponding to the upper wind box 6011 and the lower wind box 6012 to detect the temperature in the heating chamber 60 and transmit the temperature signal to the controller in real time, so that the controller can control the start and stop of the burner 101 and the circulating fan 501 according to the temperature of the heating chamber 60. The burner 101 and the circulating fan 501 can adopt existing products such as the RC series axial flow hot air circulating fan 501.

[0055] The first air inlet pipe 50 is provided with an exhaust port 502 to facilitate the exhaust of part of the hot air.

[0056] The exhaust pipe 40 is equipped with an exhaust fan 401 to facilitate exhausting of smoke.

[0057] A second air inlet pipe 302 is disposed on the side of the second heat exchange chamber 30 to allow external air to enter the second heat exchange chamber 30 .

[0058] The above-mentioned embodiments are only preferred embodiments of the present invention and cannot be used to limit the scope of protection of the present invention. Any non-substantial changes and substitutions made by technicians in this field on the basis of the present invention shall fall within the scope of protection required by the present invention.

Claims

1. A secondary heat exchange tunnel furnace, characterized in that: include a combustion chamber, containing the air to be heated; a burner, connected to the combustion chamber, and adapted to heat the air to be heated in the combustion chamber; a first heat exchange chamber, wherein a first heat exchange tube communicating with the combustion chamber is installed in the first heat exchange chamber, and the first heat exchange tube is suitable for heating the air in the first heat exchange chamber; a second heat exchange chamber, wherein a second heat exchange tube communicating with the first heat exchange tube is installed in the second heat exchange chamber, and the second heat exchange tube is suitable for heating the air in the second heat exchange chamber; an exhaust pipe, connected to the second heat exchange pipe, so that the gas heated by the combustion chamber flows through the first heat exchange pipe and the second heat exchange pipe and then is discharged, and the exhaust pipe is equipped with an exhaust fan; a first air inlet pipe, arranged at a side of the first heat exchange chamber and connected to the first heat exchange chamber, the first air inlet pipe being provided with an exhaust port; a circulation fan, installed on the first air inlet pipe, suitable for conveying external air into the first heat exchange chamber through the first air inlet pipe; A heating chamber, the heating chamber is used to accommodate items to be heated; An air box is installed in the heating chamber and communicated with the first heat exchange chamber. A plurality of exhaust holes are provided on the surface of the air box. The air heated by the first heat exchange chamber enters the heating chamber through the air box and is discharged through the plurality of exhaust holes. a circulation pipe, wherein the inlet of the circulation pipe is communicated with the heating chamber, and the outlet of the circulation pipe is communicated with the first air inlet pipe, so that the hot air in the heating chamber flows into the first air inlet pipe and enters the first heat exchange chamber for heating together with the external air; The first connecting pipe is connected to the circulation pipe and the second heat exchange chamber respectively, so that the heated air in the second heat exchange chamber enters the wind box through the circulation pipe and the first heat exchange chamber, and is discharged from the heating chamber through the plurality of exhaust holes.

2. A secondary heat exchange tunnel furnace as claimed in claim 1, characterized in that: It also includes an adjusting mechanism, which includes a rotating rod and a baffle. The wind box also includes an adjusting pipe and an upper wind box. The adjusting pipe is arranged at the upper end of the upper wind box. The upper wind box is connected to the first heat exchange chamber through the adjusting pipe. The baffle is arranged in the adjusting pipe. One end of the rotating rod is placed in the adjusting pipe and fixedly connected to the baffle. An air hole for heated air to pass through is formed between the baffle and the inner wall of the adjusting pipe. The rotating rod is suitable for rotating under the action of external force and driving the baffle to rotate together to adjust the size of the air hole.

3. A secondary heat exchange tunnel furnace as claimed in claim 2, characterized in that: The wind box also includes a lower wind box and a second connecting pipe connecting the regulating duct and the lower wind box. The upper wind box is arranged at the upper end of the lower wind box. The exhaust hole is arranged on the opposite sides of the upper wind box and the lower wind box. A storage space for placing items to be heated is formed between the upper wind box and the lower wind box.

4. A secondary heat exchange tunnel furnace as claimed in claim 3, characterized in that: A plurality of second guide plates are provided at the connection between the lower wind box and the second connecting pipe.

5. A secondary heat exchange tunnel furnace as claimed in claim 2, characterized in that: A plurality of first guide plates are provided at the connection between the upper wind box and the regulating duct, and the first guide plates are suitable for guiding the heated air entering the upper wind box from the regulating duct.

6. The secondary heat exchange tunnel furnace according to claim 1, characterized in that: A plurality of third guide plates are provided at the connection end between the circulation pipe and the heating chamber.

7. The secondary heat exchange tunnel furnace according to claim 1, characterized in that: It also includes a controller. A temperature sensor is provided in the heating chamber. The controller is electrically connected to the temperature sensor, the burner and the circulating fan.

8. The secondary heat exchange tunnel furnace according to claim 1, characterized in that: A second air inlet pipe is arranged on the side of the second heat exchange chamber to allow external air to enter the second heat exchange chamber.

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