Improved rake furnace

Abstract

The utility model discloses an improved rake furnace which comprises a furnace body, a middle shaft is arranged in the furnace body, one end of the middle shaft is fixedly connected with an output shaft of a driving motor, a plurality of layers of furnace beds are arranged in the furnace body from top to bottom, a plurality of rake arms are arranged above each layer of furnace bed, one end of each rake arm is fixedly connected with the middle shaft, and the other end of each rake arm is fixedly connected with the driving motor. A plurality of rake teeth are arranged on each rake arm, a high-temperature-resistant metal chain is additionally arranged between every two adjacent rake teeth of each rake arm, and the length of the free end of each high-temperature-resistant chain is larger than that of each rake tooth and is close to the hearth. The rake arm operates to drive the chain to operate, the contact area of materials and the chain is increased, the mobility of the materials on the hearth is improved, and therefore the working efficiency of the multi-section furnace is improved.

Description

Technical Field

[0001] The utility model relates to a rake type furnace, in particular to an improved rake type furnace. Background Art

[0002] The rake furnace, also known as a multi-chamber furnace or a mechanical furnace, is a multi-chamber incinerator with a mechanical transmission device. It consists of an upright cylindrical metal shell with a refractory lining, and a series of horizontal disc-shaped "hearths" arranged in parallel in the shell. The inner wall of the furnace is built with lightweight refractory bricks, allowing an operating temperature of up to 1300°C. The hearth is self-supportingly built into a vault structure using special shaped refractory bricks. The central axis runs through the entire furnace body in the vertical direction. A cantilevered "rake arm" is installed on the central axis at the corresponding position on each layer of the hearth, and a "rake tooth / stirring plow" is installed on the rake arm. The rake arm and rake teeth are driven by the rotation of the central axis, so that the solid material is mechanically pushed and passes through the entire furnace. During use, different temperature zones can be set according to process requirements. Under the action of the central axis-rake arm-rake tooth system, the roasted minerals can pass through the furnace's drying and preheating zone (furnace temperature 100-300°C), volatilization zone (350-600°C), pyrolysis zone (or sintering zone, 850-1300°C), cooling stage, and then leave the furnace and enter the next section.

[0003] Rake furnaces are mainly used for: carbonization treatment in the preparation of activated carbon; thermal regeneration of activated carbon; roasting and forging of concentrate tailings; roasting and forging of metallurgical by-products; roasting and forging of magnesium-calcium-manganese carbonates; roasting and forging of kaolin, molybdate, dolomite, sulfate, and sulfate; pyrolysis and incineration of sludge, etc.

[0004] The existing rake furnace hearth is horizontally set, and there are gaps between the rake teeth, which leads to poor fluidity of some materials in the hearth. The materials are accumulated in the hearth for a long time, resulting in great material loss and significantly reducing the recycling and extraction rate of the materials. At the same time, due to the long-term accumulation of materials, the resistance of the rake arms to the rake teeth during rotation increases, and the rake teeth are even buried in the materials as a whole, which can easily cause the rake teeth and even the rake arms to be knocked, missing or broken. Summary of the invention

[0005] The utility model aims to overcome the disadvantages of the prior art and provide an improved rake furnace which enables the furnace bed materials to flow, improves the fluidity of the materials in the rake furnace and improves the efficiency of the rake furnace.

[0006] The technical solution of the utility model is:

[0007] The utility model discloses an improved rake-type furnace, comprising a furnace body, in which a central axis is installed in a vertical direction, one end of the central axis passes through the furnace body and is fixedly connected with the output shaft of a driving motor, a material inlet and a smoke exhaust port are opened on the top wall of the furnace body, a material discharge port is opened on the bottom wall of the furnace body, and a multi-layer furnace bed is arranged in the furnace body from top to bottom, the multi-layer furnace bed is alternately connected with the inner wall of the furnace body or the central axis, a center discharge port is left between the furnace bed connected to the inner wall of the furnace body and the central axis, a side discharge port is left between the furnace bed connected to the central axis and the inner wall of the furnace body, combustion nozzles are respectively installed on the inner wall of the furnace body between the upper and lower furnace beds, a plurality of rake arms are arranged above each layer of the furnace bed, one end of each rake arm is fixedly connected with the central axis, a plurality of rake teeth are arranged on each rake arm, and furnace doors are respectively opened on the furnace body between the upper and lower furnace beds, and a high-temperature resistant metal chain is added between adjacent rake teeth of each rake arm, and the free end length of the high-temperature resistant chain is greater than the rake tooth length and is close to the furnace bed.

[0008] Compared with the prior art, the utility model has the following advantages:

[0009] 1. The utility model adopts the natural sinking of the chain in a free state, which has little contact force with the refractory bricks and little damage to the refractory materials;

[0010] 2. The powder is driven by the chain. When it accumulates to a certain height, the rake teeth transport the material to the discharge port, which can reduce material backlog and loss and improve material recovery rate;

[0011] 3. The chain can be set in front of the rake teeth to reduce the direct contact between the rake teeth and the material and act as a buffer to protect the rake teeth;

[0012] 4. Drive and strengthen the stirring of materials between the rake teeth and the furnace bed, enhance mass transfer and heat transfer, and make the reaction more complete;

[0013] 5. The length, position and angle of the chain can be adjusted as needed to clean up the backlog of materials in every corner;

[0014] 6. The chain can store heat, making the temperature inside the furnace insensitive to changes in the external environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a structural schematic diagram of a rake type furnace with a rake arm increasing device of the utility model;

[0016] Figure 2 yes Figure 1 A schematic diagram of the partial structure of a rake arm increasing device in a rake type furnace shown;

[0017] Figure 3 yes Figure 2 The chain shown in is a front view after lying flat; DETAILED DESCRIPTION

[0018] The utility model is further described below in conjunction with the accompanying drawings and specific implementation cases.

[0019] As shown in the accompanying drawings, the utility model provides an improved rake-type furnace, comprising a furnace body 1, in which a central axis 3 is installed in the vertical direction, one end of the central axis passes through the furnace body and is fixedly connected to the output shaft of a driving motor 9, a material inlet 2 and a smoke exhaust port 6 are opened on the top wall of the furnace body, a discharge port 12 is opened on the bottom wall of the furnace body, and a multi-layer furnace bed 4 is arranged from top to bottom in the furnace body, the multi-layer furnace bed is alternately connected to the inner wall or the central axis of the furnace body, a center discharge port 7 is left between the furnace bed connected to the inner wall of the furnace body and the central axis, a side discharge port 8 is left between the furnace bed connected to the central axis and the inner wall of the furnace body, combustion nozzles 13 are respectively installed on the inner wall of the furnace body between the upper and lower furnace beds, a plurality of rake arms 5 are arranged above each layer of the furnace bed, one end of each rake arm 5 is fixedly connected to the central axis, a plurality of rake teeth 10 are arranged on each rake arm 5, and furnace doors 14 are respectively opened on the furnace body between the upper and lower furnace beds.

[0020] In order to better improve the turning efficiency of the rake arm 5 and the rake teeth 10, a high temperature resistant metal chain 11 is installed between the adjacent rake teeth of each rake arm 5, and the free end length of the high temperature resistant chain 11 is greater than the length of the rake teeth and close to the furnace bed 4. The specific installation method is: the chain 11 is installed in the gap between the two rake teeth 10. Preferably, the two ends of the high temperature resistant metal chain 11 are connected to the rake arm 5 in the form of full welding. After being fixed by the full welding form, the chain is not easy to fall off when the rake arm 5 is working. Preferably, the volume of a single high temperature resistant metal chain 11 is smaller than the gap m between the two rake teeth 10 to ensure that it will not be stuck between the rake teeth 10 after breaking, during the actual installation and selection process of the chain. Considering the thermal expansion and contraction of steel, the thickness L of a single high temperature resistant metal chain 11 is 2-4mm smaller than the distance h between the rake teeth 10 and the furnace bed 4, so as to avoid the welding part at the end of the chain from being stuck therein after being desoldered under long-term high temperature and acidic conditions, causing the rake teeth to break.

[0021] The working process of this device is as follows:

[0022] The central axis 3 is driven by the bottom central axis driving motor 9, and the rake arm 5 is fixed on the central axis through mechanical parts such as pipa buckles and follows the operation, so that the rake teeth 10 and the high temperature resistant chain 11 on the rake arm perform circular motion around the central axis.

[0023] The high temperature resistant chain 11 can sweep local materials and accumulate them to a certain height. As the rake teeth 10 gradually move toward the discharge port, the material flow in the furnace is increased, and material accumulation and dead corners are reduced. The bottom of the chain 11 in the free fall state needs to exceed the rake teeth 10 and approach the hearth 4. When the rake arms 5 are working, the chain 11 will clear the missed accumulated materials between the rake teeth 10 and the hearth 4.

[0024] After the rake arm 5 is equipped with the high temperature resistant metal chain 11, the high temperature resistant metal chain 11 is driven by the rake arm 5 to rotate. When encountering a heavier pile of materials, the rake arm 5 will provide a supporting force for the chain, and the high temperature resistant metal chain 11 can easily remove the pile of materials. The temperature in the rake furnace can reach above 800°C, and high temperature resistant steel 310S can be selected as the material to ensure that the chain 11 will not be easily deformed, thereby increasing the service life of the chain 11.

[0025] The above-mentioned embodiments are only preferred embodiments for fully illustrating the present utility model, and the protection scope of the present utility model is not limited thereto. Any equivalent substitution or transformation made by technicians in this technical field based on the present utility model is within the protection scope of the present utility model. The protection scope of the present utility model shall be subject to the claims.

Claims

1. An improved rake-type furnace, comprising a furnace body, in which a central axis is installed in a vertical direction, one end of the central axis passes through the furnace body and is fixedly connected to the output shaft of a driving motor, a material inlet and a smoke exhaust port are opened on the top wall of the furnace body, a discharge port is opened on the bottom wall of the furnace body, and a multi-layer furnace bed is arranged from top to bottom in the furnace body, the multi-layer furnace bed is alternately connected to the inner wall of the furnace body or the central axis, a center discharge port is left between the furnace bed connected to the inner wall of the furnace body and the central axis, a side discharge port is left between the furnace bed connected to the central axis and the inner wall of the furnace body, combustion nozzles are respectively installed on the inner wall of the furnace body between the upper and lower furnace beds, a plurality of rake arms are arranged above each layer of the furnace bed, one end of each rake arm is fixedly connected to the central axis, a plurality of rake teeth are arranged on each rake arm, and furnace doors are respectively opened on the furnace body between the upper and lower furnace beds, characterized in that: A high temperature resistant metal chain is installed between adjacent rake teeth of each rake arm. The free end of the high temperature resistant chain is longer than the length of the rake teeth and is close to the furnace bed.

2. The improved rake furnace according to claim 1, characterized in that: The volume of a single high temperature resistant metal chain is smaller than the gap between two rake teeth.

3. The improved rake furnace according to claim 1 or 2, characterized in that: The thickness L of a single high temperature resistant metal chain is 2-4 mm smaller than the distance h between the rake teeth and the hearth.

4. The improved rake furnace according to claim 3, characterized in that: The two ends of the high temperature resistant metal chain are fixed to the rake arm by full welding.

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