CN211233363U

CN211233363U - Indirect hot-blast stove

Info

Publication number: CN211233363U
Application number: CN201921625157.8U
Authority: CN
Inventors: 闵春华; 王迪; 王坤; 谢立垚; 王进
Original assignee: Hebei University of Technology
Current assignee: Hebei University of Technology
Priority date: 2019-09-27
Filing date: 2019-09-27
Publication date: 2020-08-11
Anticipated expiration: 2029-09-27

Abstract

The utility model relates to an indirect hot-blast furnace. The method is characterized in that: the hot blast stove is provided with a cold air inlet, a hot air outlet, a flue gas inlet, a flue gas outlet, a heat exchange coil, a baffle plate, a flue gas diversion bin, an air diversion bin, a heat exchange bin, a hot blast stove shell, a fan, a wet filtering device, a combustion hearth, a supporting plate and a pressure valve according to the process requirements; the hot blast stove main body is of a square structure, an air inlet and an air outlet are formed in one side of the hot blast stove main body, air enters the heat exchange bin from the bottom of the hot blast stove main body and is discharged from an outlet in the top after the heat exchange process; the inlet and the outlet of the heat exchange coil are arranged on the other side of the indirect hot air furnace shell, flue gas enters the coil and then circulates through the flue gas diversion bin to exchange heat with air, the air flow channel in the heat exchange bin is prolonged by arranging the baffle plate, and the air diversion bin is additionally arranged.

Description

Indirect hot-blast stove

Technical Field

The utility model relates to a drying equipment of classification product processing such as medicine and food, for example an indirect hot-blast furnace, especially be applicable to the indirect hot-blast furnace that uses the natural gas as combustion medium.

Background

The gas hot blast stove is one kind of stoving equipment for stoving medicine, food and other products with high temperature fume. The use occasions of the gas hot blast stove are limited to a certain extent. When the materials which are not allowed to be polluted are dried, indirect hot blast stoves are mostly adopted. The working principle of the indirect hot blast stove is that the air flow channel is heated by high-temperature flue gas, the inner surface of the flow channel exchanges heat with air, the air is prevented from being polluted by the flue gas, and the heated air directly dries materials. The fuel of the hot blast stove is gradually changed into clean energy mainly comprising natural gas. Water vapor is present in the natural gas combustion products. When the temperature is higher, the water vapor is in a gaseous state, and after heat exchange with air, the temperature of the water vapor is reduced, so that phase change occurs.

Zhang Shi is widely put forward 'an indirect hot blast stove' in 'a full-automatic indirect heat exchange type hot blast stove (refer to CN207702730U, 2018-08-07)': one end of the cylindrical furnace is a flue gas inlet connected with a hearth, flue gas enters the heat exchanger and then is discharged from the side, and cold air enters the cylindrical furnace from the inlet on the side and flows to the other end of the hot blast furnace along a flow passage to be discharged. However, the designed indirect hot blast stove has narrow air flow passage and short flow path, and is easy to cause the technical problems of small outlet hot air flow, insufficient heat exchange and the like.

Disclosure of Invention

In order to solve the technical problem, the utility model provides a novel indirect hot blast stove. It is through changing the structure of the inside heat exchange assembly of hot-blast furnace, at the inside heat exchange coil that arranges of rectangle casing to divide into suitable layer with the shell side through the baffling board, the air flows in the runner that shell side wall face and baffling board are constituteed, thereby prolongs the flow path of cold air greatly, has improved the work efficiency of hot-blast furnace, handles the liquid water that vapor phase transition produced simultaneously. The utility model has the advantages of simple structure and high fuel utilization rate.

For solving the deficiency of the prior art, the utility model adopts the following design scheme: design an indirect hot-blast furnace, the appearance of this hot-blast furnace is the cuboid, its characterized in that: the indirect hot blast stove is divided into two layers, wherein the interior of the indirect hot blast stove is a heat exchange bin part for flue gas-air heat exchange, and the exterior of the indirect hot blast stove is a heat insulation layer which plays roles in heat insulation and heat exchange bin protection; the internal heat exchange bin is divided into a shell pass flow channel internally flowing air and a heat exchange coil pipe internally flowing smoke, the shell pass air flow channel consists of the wall surface of the heat exchange bin and baffle plates, the shell pass air flow channel is divided into four layers from bottom to top, and the baffle plates are connected with the inner wall of the heat exchange bin in a welding mode; in order to ensure that the flue gas coil pipe in the heat exchange bin is heated uniformly, and air cannot form heat exchange dead angles in the flowing process, each layer of air flow channel is connected through the air diversion bin, and the air diversion bin is welded with the outer wall surface of the heat exchange bin and extends outwards from the wall surface of the heat exchange bin.

The heat exchange coils are fully arranged in the air flow channel, 4-6 layers of heat exchange coils are arranged in each layer of air flow channel, the machining allowance of each layer of heat exchange coils ensures that 14-21 rows of coils are installed, and the adjustment is carried out according to the actual machining condition. In the single-layer air flow channel, each row of coil pipes are in one group, smoke flows to the next group or the next groups from one group or a plurality of groups of coil pipes through the diversion bin, alternately flows in the air flow channel of one layer, flows to the last group or a plurality of groups of coil pipes of the layer, enters the coil pipe of the next layer through the diversion bin until the smoke flows out of the heat exchange bin.

The heat exchange bin is divided into a shell pass flow channel with air flowing inside and a heat exchange coil pipe with flue gas flowing inside, the shell pass air flow channel consists of a wall surface of the heat exchange bin and a baffle plate and is divided into four layers from bottom to top, each layer of air flow channel is connected through a flow guide bin, so that the air flows in a Z shape inside the flow channel, and the air vertically scours the heat exchange coil pipe in the flow channel.

Compared with the prior art, the beneficial effects of the utility model are that:

1 is provided with a dehumidifying and filtering device, thereby improving the working efficiency. The dehumidification filtering device is arranged at the cold air inlet of the hot blast stove, the structure is simple, the work is reliable, and the filter element can be replaced in the dehumidification filtering device; the filter element is inserted into the hot blast stove through the slide way on the right side, and the main purpose is to ensure that the air entering the heat exchange bin is dry enough, so that the hot air at the outlet can carry away more moisture when drying the materials. After the filter element is used for a period of time, the filter element can be taken out from the slideway for cleaning, and meanwhile, the drying agent is replaced, so that the working effect of the filter element is ensured.

2 ensuring the heat exchange effect. The utility model discloses the flue gas in the air that flows in the heat transfer storehouse and the coil is the opposite direction flow on the general flow trend, and the temperature of flue gas risees along the flow direction of cold air gradually in the coil to guarantee the heat transfer effect of air at the flow in-process.

3, the heat exchange efficiency is improved. The utility model discloses the inside heat exchange coil pipe of device adopts the internal thread pipe, because the working medium that flows in the coil pipe is the flue gas, and heat transfer capacity is limited, uses the internal thread pipe not only to increase the disturbance of the flue gas flow in-process, has still increased the area of contact of flue gas with the wall, has improved heat exchange efficiency.

4 baffle plates are additionally arranged. The utility model adds baffle plates in the heat exchange bin. The heat exchange part of the shell pass is prolonged by the baffle plate, so that the heat exchange is more sufficient. The shell pass part of the air flow channels are connected through the diversion bin, and air flows through one layer of flow channel and then enters the diversion bin, so that the air flows into the next section of flow channel more stably, and vortex or uneven heat exchange caused by air flowing in the heat exchange bin is avoided.

5 the applicable process range is wide. The utility model discloses shell side and the inside operating pressure of tube side are the ordinary pressure. In order to avoid the problems of sonic boom and the like caused by over-high flue gas flow velocity in the pipe pass, a flue gas inlet is changed into four branch pipes for supporting after entering the heat exchange bin. The event the utility model discloses a tube side can be operated under the operating mode of the higher velocity of flow of working medium.

6, the influence of the condensed water on the heat exchange system can be avoided. The utility model discloses indirect hot-blast furnace utilizes the condensate water that the pressure valve produced after to the heat transfer to handle, can avoid the influence of condensate water to the heat transfer system.

Drawings

Fig. 1 and fig. 2 are schematic views of the overall structure of an embodiment of the indirect hot blast stove of the present invention;

fig. 3 is a schematic sectional view of an internal thread branch pipe structure according to an embodiment of the indirect hot blast stove of the present invention.

In the figure, 1-a cold air inlet, 2-a hot air outlet, 3-a smoke inlet, 4-a smoke outlet, 5-a heat exchange coil, 6-a baffle plate, 7-a smoke diversion bin, 8-an air diversion bin, 9-a heat exchange bin, 10-a hot air furnace shell, 11-a fan, 12-a dehumidifying and filtering device, 13-a combustion furnace chamber, 14-a supporting plate and 15-a pressure valve.

Detailed Description

The present invention will be described in further detail with reference to the following examples and accompanying drawings, but the present invention is not limited thereto.

The indirect hot blast stove (hot blast stove for short, see figure 1-2) designed by the utility model is cuboid in shape. The method is characterized in that: a cold air (cold air) inlet 1 is arranged at the bottom of the cuboid shell, a thin dehumidification filtering device 12 is arranged in a manner of extending a certain distance from the cold air inlet 1 to the heat exchange bin, and the dehumidification filtering device extends from the heat exchange bin 9 to the outside of an indirect hot air furnace shell 10; cold air is blown into the heat exchange bin 9 through the fan 11, the baffle plate 6 is arranged inside the heat exchange bin 9, and the left side wall surface and the right side wall surface of the heat exchange bin 9 and the baffle plate form a heat exchange flow channel; the air flows from bottom to top in a Z shape in the flow channel, the heat exchange coil 5 is uniformly washed through the connection of the air diversion bin 8, and the air and the flue gas are discharged through the hot air outlet 2 after heat exchange is completed; the inlet and the outlet of the heat exchange coil 5 are arranged on one side; flue gas is provided by a combustion hearth 13, the flue gas flows into a heat exchange coil pipe 5 from a top flue gas inlet 3, the flue gas is discharged through a bottom flue gas outlet 4 after heat exchange, and condensed water flows out through a pipe orifice connected with a pressure valve 15 after being converged at the flue gas outlet; the heat exchange coil pipes are internally threaded pipes, the coil pipes in the heat exchange bin are positioned in the middle of each layer of air flow channel and connected through a flue gas diversion bin 7, and 15 rows of the coil pipes are arranged in each layer of air flow channel, and each row is provided with 4 rows; the branch span is too long and a support plate 14 is provided in the middle of each group of branch pipes.

The heat exchange coil 5 and the shell of the hot blast stove heat exchange bin are connected in a welding mode. The flue gas inlet 3 is designed as a rectangular channel and is connected with the combustion furnace 13 at the inlet end through a connector.

The outer wall surface of the heat exchange bin 9 is provided with a flue gas diversion bin 7, and the flue gas diversion bin 7 extends outwards from the outer wall surface of the heat exchange bin 9. Because the gas heat exchange capacity is weaker, the effect of simply increasing the heat exchange area is not obvious, the internal thread pipe also influences the smoke flowing in the pipe pass while increasing the heat exchange area, a thermal boundary layer formed in the smoke flowing process in the pipeline is damaged, and the heat in the smoke is effectively transferred out.

The heat exchange coils are fully arranged in the air flow channel, 4 layers of heat exchange coils are arranged in each layer of air flow channel, and each layer of heat exchange coils is 15 rows in total and can be adjusted according to actual processing conditions. In the top air flow channel, the flue gas flows into the heat exchange coil pipe through the flue gas inlet, alternately flows in the air flow channel of the layer through the flue gas diversion bin and the heat exchange coil pipe, flows to the last row of heat exchange coil pipe of the layer, and then flows into the next layer through the flue gas diversion bin. The flue gas flows in the heat exchange coil pipe alternately, flows through the four layers of air flow channels and is discharged from the flue gas outlet.

The air diversion bin extends outwards from the heat exchange bin, so that air stably flows through the heat exchange coil.

The key points are as follows: the design of the internal thread branch pipe, the arrangement of the baffle plate and the application of the air diversion bin. The flue gas can be disturbed when flowing in the coil pipe, so that more heat in the flue gas is transferred to the coil pipe; the baffle plate in the heat exchange bin is arranged for guiding cold air to flow, and the operation mode of the indirect hot blast stove is changed by adjusting the structure of the indirect hot blast stove, so that the flow distance of the indirect hot blast stove is prolonged, and the heat exchange is more sufficient; the air diversion bin is used for guiding the working medium in the air flow channel to run along a set route, so that the reduction of heat exchange capability caused by the unsmooth flow is avoided.

The utility model discloses the theory of operation and process of hot-blast furnace are as follows: the working principle of the indirect hot blast stove is that smoke is used for heating air, so that a series of materials which are not allowed to be polluted, such as food, medicines and the like, are dried. The utility model discloses a baffling board makes the flow increase of heat transfer storehouse part, more general indirect hot-blast furnace the utility model discloses heat transfer area greatly increased, thereby the increase the utility model discloses a heat exchange efficiency. The condensed water generated by the reduction of the temperature of the flue gas is discharged through the pipe orifice connected with the pressure valve, so that the condensed water can be prevented from remaining in the heat exchange coil.

High-temperature flue gas enters from a flue gas inlet at the top of the indirect hot blast stove and flows regularly in the heat exchange bin through the heat exchange coil pipe, and the fins on the pipe wall improve the heat exchange efficiency. The flue gas diversion bins alternately flow in the same layer of air flow channel, extend outwards, and are connected through the diversion bin, so that the processing amount of the indirect hot blast stove is reduced.

The cold air flows in from a cold air inlet at the bottom of the equipment and passes through the dehumidifying and filtering device. The dehumidifying and filtering device can dry air and make the air entering the hot blast stove cleaner. The air enters the heat exchange bin after being dehumidified and filtered, exchanges heat in the flow channel between the heat exchange coil pipes, and is discharged from the hot air outlet at the top after flowing through the whole coil pipe structure. The dehumidification filter device reduces noise during operation through the processing mode of connecting the branch pipe with the main pipe, the heat exchange is more sufficient due to the use of the diversion bin, the dehumidification filter device is easier to process, the air flow channel is prolonged due to the baffle plate, the heat exchange process is more sufficient, and therefore the purposes of saving raw materials, saving energy and reducing consumption are achieved.

The utility model discloses the cold wind import and the hot air exitus of indirect hot-blast furnace arrange at the same face, and heat exchange coil's import and export are arranged in its side, are convenient for settle and operate. In order to ensure that the flow resistance is not too large when air flows through the heat exchange coil, the space between every two metal tubes is designed and arranged according to the national standard, the space between every two metal tubes is 1.4-1.6 times of the diameter of the metal tubes, and the heat exchange area of the coil in the model is enough to ensure the requirement of a heat exchange part.

The utility model discloses a pipeline is extended and pressure valve is set up in indirect hot-blast stove flue gas coil's exit, and the condensate water that produces among the flue gas heat transfer process collects the flue gas coil exit, accumulates to a certain amount and makes pressure valve opening drainage, and water pressure reduces to a certain degree pressure valve closure, and the condensate water accumulates again and repeats above-mentioned process.

The heat-insulating layer is made of rock wool.

Claims

1. An indirect hot blast stove is provided with a cold air inlet, a hot air outlet, a flue gas inlet, a flue gas outlet, a heat exchange coil, a baffle plate, a flue gas diversion bin, an air diversion bin, a heat exchange bin, a hot blast stove shell, a fan, a dehumidification filtering device, a combustion hearth, a supporting plate and a pressure valve according to the technological requirements; the hot blast stove main body is of a square structure, one side of the hot blast stove main body is provided with an air inlet and an air outlet, air enters the heat exchange bin from the bottom of the hot blast stove and is discharged from an outlet at the top after the heat exchange process, the flue gas coil inlet and the flue gas coil outlet are arranged at the other side of the indirect hot blast stove shell, flue gas enters the coil and circulates through the flue gas diversion bin to exchange heat with air, an air flow passage in the heat exchange bin is prolonged by arranging a baffle plate, and the air diversion bin is additionally arranged, so that the local uneven heat exchange; the method is characterized in that: the hot blast stove is divided into two layers, wherein the inside of the hot blast stove is a heat exchange bin part for flue gas-air heat exchange, and the outside of the hot blast stove is a heat insulation layer which plays roles of heat insulation and heat exchange bin protection; the internal heat exchange bin is divided into a shell pass flow channel internally flowing air and a heat exchange coil pipe internally flowing smoke, the shell pass air flow channel consists of the wall surface of the heat exchange bin and baffle plates, the shell pass air flow channel is divided into four layers from bottom to top, and the baffle plates are connected with the inner wall of the heat exchange bin in a welding mode; in order to ensure that the flue gas coil pipe in the heat exchange bin is heated uniformly, and air cannot form heat exchange dead angles in the flowing process, each layer of air flow channel is connected through the air diversion bin, and the air diversion bin is welded with the outer wall surface of the heat exchange bin and extends outwards from the wall surface of the heat exchange bin.

2. The indirect hot blast stove according to claim 1, characterized in that: divide into four layers from supreme down, every layer of air runner passes through the water conservancy diversion storehouse and connects, makes the air flow in the inside "Z" style of calligraphy of runner, and the air erodees heat exchange coil pipe perpendicularly in the runner.

3. The indirect hot blast stove according to claim 1, characterized in that: the heat exchange coils are fully distributed in the air flow channels, 4-6 layers of heat exchange coils are arranged in each layer of air flow channel, the machining allowance of each layer of heat exchange coils ensures that 14-21 rows of coils are installed, and the adjustment is carried out according to the actual machining condition; in the single-layer air flow channel, each row of coil pipes are in a group, smoke flows from one group of coil pipes to the next group through the flow guide bin, alternately flows in the air flow channel of one layer, flows to the last group of coil pipes of the layer, and then enters the coil pipes of the next layer through the flow guide bin until the smoke flows out of the heat exchange bin.

4. The indirect hot blast stove according to claim 1, characterized in that: the air diversion bin extends outwards from the heat exchange bin, so that air stably flows through the heat exchange coil.

5. The indirect hot blast stove according to claim 1, characterized in that: the air inlet and outlet, and the inlet and outlet of the flue gas coil are both arranged on one side of the hot blast stove.

6. The indirect hot blast stove according to claim 1, characterized in that: the heat exchange coil pipe branch pipe is an internal thread pipe, and the outer surface of the heat exchange coil pipe branch pipe is provided with a spiral fin.

7. The indirect hot blast stove according to claim 1, characterized in that: the distance between every two metal tubes is 1.4-1.6 times of the tube diameter.

8. The indirect hot blast stove according to claim 1, characterized in that: the heat-insulating layer is made of rock wool.