CN218495746U - A waste heat recovery mesh belt dryer - Google Patents

Abstract

The utility model relates to a waste heat recovery net belt dryer, its characterized in that: including desiccator organism, conveying system, sack cleaner, comdenstion water heat exchanger, tail gas processing system, recovery pipeline, intake stack, preheat pipeline and exhaust emission pipeline, both ends are provided with feed inlet and discharge gate respectively about the desiccator casing, the desiccator organism turn right from a left side by a plurality of independent casing and connect gradually and constitute. The utility model has the advantages of reasonable design, convenient to use carries out the reutilization to the hot water and the steam that flow from the medium outlet of main heat exchanger, reduces steam consumption, eliminates the potential safety hazard because of steam splash brings simultaneously, has solved the problem that exists among the prior art.

Description

A waste heat recovery mesh belt dryer

technical field

The utility model relates to the technical field of drying equipment, in particular to a waste heat recovery mesh belt dryer.

Background technique

With the development of industrial production technology, higher requirements are put forward for drying equipment. High efficiency, low consumption, high quality and low pollution have become the main indicators of a set of drying equipment, especially for chemical manufacturers to effectively reduce energy consumption, It is of great practical significance to reduce production costs and improve market competitiveness.

The drying equipment mainly used in the production process of organic pigments and other pasty fine chemical products are: hot air circulation oven, belt dryer, spin flash dryer, spray dryer, etc. The belt dryer has high production efficiency, high degree of automation, stable product quality, and high thermal efficiency. With the continuous improvement and improvement of the belt dryer, its use is becoming more and more popular, and it has become the production process of organic pigments and other pasty fine chemical products. The equipment of choice for medium drying units. However, during the use of the existing belt dryer, the high-temperature gas used for heating is often discharged directly after drying, resulting in a great waste of energy. Therefore, in order to solve the above problems, a waste heat recovery network is designed The belt dryer is particularly important.

Contents of the invention

In order to solve the above problems, the utility model designs a waste heat recovery mesh belt dryer, which not only preheats the gas entering the drying chamber through the condensed water heat exchanger, but also reheats the heated gas in the drying chamber and transports it into the preheating chamber. The dry section heats the room for reuse, which reduces energy consumption and saves resources, and increases practical performance.

In order to solve the above technical problems, the utility model provides a waste heat recovery mesh belt dryer, which is characterized in that it includes a dryer body, a conveying system, a bag filter, a condensed water heat exchanger, an exhaust gas treatment system, and a recovery pipeline , air inlet pipe, preheating pipe and tail gas discharge pipe. The left and right ends of the dryer casing are respectively provided with a feed inlet and a discharge outlet. The dryer body is composed of several independent shells from the left It is composed of connections to the right in turn, and several independent shells are connected in turn, among which half of the independent shells near the feed inlet form the heating chamber of the pre-drying section, and the remaining half of the independent shells form the drying chamber. There is a partition installed vertically in the body, and the partition divides the inner space of the shell into a conveying chamber and a gas heating chamber. The upper and lower ends of the partition are provided with openings for the conveying chamber to communicate with the gas heating chamber. The through hole, the conveying system is arranged in the body of the dryer and passes through several conveying chambers in turn, the air inlet pipe is arranged on one side of the body of the dryer and communicates with half of the gas heating chamber of the drying chamber, so The above-mentioned air inlet pipe is connected with the heat exchange outlet of the condensed water heat exchanger, one end of the recovery pipe is connected to the top of the drying chamber, and the other end of the recovery pipe is connected with the recycling pipe through the bag filter. The reuse pipeline is in communication with the pre-heating pipeline. The pre-heating pipeline is also arranged on one side of the dryer body and communicates with the seven gas heating chambers in the heating chamber of the pre-drying section. One end of the tail gas discharge pipeline It is connected to the top of the heating chamber of the pre-drying section, and the other end of the tail gas discharge pipe is connected with the tail gas treatment system.

Further: the top of the heating chamber of the pre-drying section is provided with a first diversion pipe, the first diversion pipe communicates with the delivery chamber and is connected with the tail gas discharge pipe through the second diversion pipe, the pre-drying section The top of the conveying chamber of the heating chamber is also provided with a first blower for circulating the heating gas.

Still further: the top of the drying chamber is provided with a third diversion pipe, the third diversion pipe communicates with the gas heating chamber and is connected with the recovery pipe through the fourth diversion pipe, the gas heating chamber of the drying chamber The top is also provided with a second fan for heating gas circulation.

Still further: the heating chamber of the pre-drying section and several gas heating chambers of the drying chamber are all provided with electric heating devices.

A further step: the tail gas treatment system is a spray absorption wet dust collector.

After adopting the above-mentioned structure, the utility model has a reasonable structure design, uses the hot water and hot air after the heat exchange of the main heat exchanger for secondary use, preheats the air, and can heat the air to a higher temperature during the secondary heating, which can Reduce the total steam consumption during material drying; at the same time, the heat in the steam is more utilized, and the final discharge is basically hot water, basically no high-temperature steam is discharged, reducing the safety hazard caused by high-temperature steam splashing. In addition, using this The utility model belt dryer preheats the air, which can reduce the fluctuation of the inlet air temperature caused by environmental changes, make the temperature in the drying tower more stable, and avoid product quality problems caused by temperature fluctuations.

Description of drawings

Below in conjunction with accompanying drawing and specific embodiment, the utility model is described in further detail.

Fig. 1 is the structural representation of the utility model.

Figure 2 is a structural diagram of the tail gas treatment system.

Figure 3 is a structural diagram of the bag filter.

Fig. 4 is a diagram of the internal structure of the heating chamber of the pre-drying section.

Fig. 5 is a diagram of the internal structure of the drying chamber.

Detailed ways

A waste heat recovery mesh belt dryer as shown in Figure 1, Figure 2, Figure 3, Figure 4 and Figure 5, including a dryer body 1, a conveying system 16, a bag filter 7, a condensed water heat exchanger 4, Tail gas treatment system 9, recovery pipeline 15, air inlet pipeline 6, preheating pipeline 10 and tail gas discharge pipeline 24, the left and right ends of the dryer casing are respectively provided with a material inlet 1-1 and a material outlet 1-2 , the body of the dryer is composed of several independent shells connected sequentially from left to right, and several independent shells are connected successively, among which half of the independent shells near the feed inlet form the pre-drying section heating room, the remaining half of the shells constitute the drying room, and a partition is arranged vertically inside the shell, and the partition divides the inner space of the shell into a conveying chamber and a gas heating chamber, and the upper and lower sides of the partition Both ends are provided with through holes for the communication between the conveying chamber and the gas heating chamber. The conveying system is arranged in the body of the dryer and passes through several conveying chambers in sequence. The air inlet pipe is arranged in one of the dryer bodies. side and it is connected with half of the gas heating chamber of the drying chamber, the air inlet pipe is connected with the heat exchange outlet of the condensed water heat exchanger, one end of the recovery pipe is connected to the top of the drying chamber, and the recovery pipe is The other end communicates with the reuse pipeline 8 through the bag filter, and the reuse pipeline communicates with the pre-heating pipeline, which is also arranged on one side of the dryer body and connected to the heating chamber The seven gas heating chambers are connected, one end of the tail gas discharge pipe is connected to the top of the pre-drying section heating chamber, and the other end of the tail gas discharge pipe is connected to the tail gas treatment system. The utility model not only preheats the gas entering the drying chamber through the condensed water heat exchanger, but also reheats the heated gas in the recovery drying chamber and transports it into the heating chamber of the pre-drying section for reuse, which reduces energy consumption and saves energy. Resources for resources that increase utility performance.

The feed inlet of the dryer body is connected with the paste-like wet material forming system, and the position of the dryer body close to the feed inlet is also provided with a material distribution system. The extruded material is evenly spread on the conveying system. Belt drying has been widely used in other industries a long time ago, but it is rarely used in paste fine chemical industries such as organic pigments; the main reason is that fine chemical products in the form of filter cakes cannot be directly dried by belt dryers, and belt dryers are required It must be pre-formed, so choosing a suitable forming system has a great influence on the performance of the belt dryer, and it has a direct impact on the uniformity of drying, equipment production capacity, energy consumption, and tail gas treatment devices. The uniform shape of the material will shorten the drying time, increase the productivity and reduce the consumption. Uneven molding will artificially increase the drying time, and at the same time, it will cause uneven material spreading on the entire mesh surface, short-circuit the hot air, increase the dehumidification temperature, and waste energy. Dust entrainment is serious, which increases the load on the exhaust gas treatment device.

The above-mentioned conveying system uses the mesh belt to drag through the chains on both sides and rotates in the drying box. The conveying system should consider the carrying capacity of the mesh belt. Because the wet material is heavy, the support rods under the mesh belt must be dense. Generally, one is connected to one Struts; There must be material baffles on both sides of the mesh belt, on the one hand to prevent material leakage, on the other hand to prevent hot air short circuit, which affects the drying capacity.

As shown in Figure 4, the top of the heating chamber of the pre-drying section is provided with a first guide pipe 18, and the first guide pipe communicates with the conveying chamber and is connected with the tail gas discharge pipe through the second guide pipe 19. The top of the conveying chamber of the heating chamber of the pre-drying section is also provided with a first blower fan for heating gas circulation; the top of the drying chamber is provided with a third guide pipe 21, and the third guide pipe is connected with the gas heating chamber The gas heating chamber of the drying chamber is also provided with a second blower for circulating the heated gas. The circulating hot air in the shell is distributed evenly on the entire mesh surface as much as possible, so the position of the air outlet and return air is designed reasonably, and the hot air short circuit phenomenon is avoided as much as possible, because the volume heat transfer coefficient is related to the wind speed passing through the material during the drying process, and the wind speed passing through the material can be improved. Increasing the volumetric heat transfer coefficient can improve the drying capacity in the constant drying stage. Windshields should be added on both sides of the mesh belt. Since the resistance of the mesh belt increases after feeding, the hot air is likely to short-circuit and circulate from both sides of the mesh belt, and the drying efficiency will decrease. In addition, the wind speed can be adjusted through the set first blower fan and the second blower fan, so as to perform better drying.

Electric heating devices 11 are installed in the heating chamber of the pre-drying section as shown in FIG. 1 and several gas heating chambers of the drying chamber.

The above-mentioned exhaust gas treatment system is a spray absorption wet dust collector, which is composed of a support plate, light pellets, a screen, and a demister. A certain amount of light spherical filler is placed on the support plate. Under the interaction of various forces such as the momentum of the airflow, the buoyancy of the liquid and its own gravity, the spherical fillers are suspended to form turbulent rotation and mutual collision, causing close contact between gas and liquid, and effectively performing mass transfer, heat transfer and dust removal. . In addition, due to the irregular movement of the balls in all directions, the surface is often collided and washed. Under a certain superficial gas velocity, it will produce its own cleaning effect and is not easy to be blocked. It has been widely used in exhaust gas purification. The exhaust gas treatment system develops the concept of fluidized bed into the gas-liquid mass transfer equipment, so that the packing in the spray tower is in a fluidized state, thus strengthening the dust removal effect. Its characteristics are: high gas velocity, large processing capacity, light tower, relatively uniform vapor-liquid distribution, and not easily blocked by solid and viscous materials. Especially because of the strong turbulence in the tower, the diameter of the tower can be greatly reduced and the height of the tower can be reduced. The dust collector handles a large air volume, the superficial air velocity is 1.5-6.0m/s, the spray density is 20-110m3/(m2·h), and the pressure loss is less than 1000Pa. The efficiency of the specially designed mist removal device can reach 98% to 99%, and the structure is simple and the pressure drop is small.

The moisture evaporation of organic pigments in the prior art is about 152kg/h (the temperature of the air inlet and outlet remains unchanged, and the moisture evaporation capacity of the dryer remains unchanged), and its initial moisture content is 0-52% (wet basis), and the final moisture content after drying 0-1% (wet basis), the drying heat source is often saturated steam, the drying mixing temperature is 80-90°C, the exhaust temperature is 50-75°C, and the tail gas dust removal part often uses a pre-drying section as a water film dust collector The drying section is a bag filter, and its water evaporation: W _water = 152kg/h; dry product output: W _dry = W _water × (1－ω ₁ )÷(ω ₁ －ω ₂ ); wet processing capacity: W _wet = 152 + 143 = 295kg/h; steam consumption per ton of dry material: 546kg/h ÷ 143kg/h ≈ 3.82 tons _{of steam} /ton of _product ; and after adopting this design, the exhaust gas in the drying section is being recycled: the drying section The exhaust air temperature of the exhaust gas is ~75°C, which can be used as fresh air in the pre-drying section, which can save energy: q ₁ =6000×0.245×(75－15)=88200kcal/h; this design utilizes the waste heat of condensed water: condensed The temperature before and after water waste heat utilization is 140°C and 75°C; energy can be saved: q ₂ =546×1×(140－75)= 35490kcal/h; this design can increase the temperature difference of fresh air in the drying section by using the waste heat of condensed water as Δt= 35490÷6000÷0.245＝24℃, fresh air temperature is ~39℃, recyclable heat: q ₁ +q ₂ ＝88200+35490＝123690kcal/h, steam consumption that can be saved: 123690÷500＝247kg/h ;The heat required for the fresh air in the pre-drying section to heat up: 6000×0.245×(110-75)=51450kcal/h; Hourly steam consumption: 51450+104370) ÷ 500 = 312kg/h, steam consumption calculation: 312 (operating steam consumption of waste heat recovery mesh belt dryer) + 247 (saved steam consumption) = 559kg/h≈ 546kg/h (the steam consumption of the existing process mesh belt dryer); the steam energy consumption per ton of product of the waste heat recovery mesh belt dryer: 312kg/h÷ 143kg/h≈2.18 tons _{of steam} /ton of _product ; the existing process network Steam energy consumption per ton of product with dryer: 546kg/h ÷ 143kg/h ≈ 3.82 tons _{of steam} /ton _{of product} ; energy saving efficiency of waste heat recovery mesh belt dryer: 312kg/h ÷ 546kg/h ≈ 57%, energy saving 40% .

To sum up, the utility model has a reasonable structural design, uses the hot water and hot air after the heat exchange of the main heat exchanger for the second time, preheats the air, and can heat the air to a higher temperature during the second heating, which can Reduce the total steam consumption during material drying; at the same time, the heat in the steam is more utilized, and the final discharge is basically hot water, basically no high-temperature steam is discharged, reducing the safety hazard caused by high-temperature steam splashing. In addition, using this The utility model belt dryer preheats the air, which can reduce the fluctuation of the inlet air temperature caused by environmental changes, make the temperature in the drying tower more stable, and avoid product quality problems caused by temperature fluctuations.

The above are only preferred implementations of the utility model, and the scope of protection of the utility model is not limited to the above-mentioned embodiments, and all technical solutions under the thinking of the utility model all belong to the scope of protection of the utility model. It should be pointed out that for those of ordinary skill in the art, some improvements and modifications without departing from the principle of the utility model should be regarded as the protection scope of the utility model.

Claims (5)

1. A waste heat recovery mesh belt dryer, characterized in that it includes a dryer body (1), a conveying system (16), a bag filter (7), a condensed water heat exchanger (4), and an exhaust gas treatment system ( 9), recovery pipe (15), air inlet pipe (6), preheating pipe 10) and tail gas discharge pipe (24), the left and right ends of the dryer casing are respectively provided with feed ports (1-1) and the discharge port (1-2), the dryer body is composed of several independent shells connected sequentially from left to right, and several independent shells are connected successively, and half of them near the feed port The independent housing forms the heating chamber of the pre-drying section, and the remaining half of the independent housings form the drying chamber. A partition is arranged vertically inside the housing, and the partition divides the inner space of the housing into a conveying chamber and a In the gas heating chamber, the upper and lower ends of the partition are provided with through holes for the communication between the conveying chamber and the gas heating chamber. The conveying system is arranged in the body of the dryer and passes through several conveying chambers in sequence. The air inlet pipe is arranged on one side of the dryer body and communicates with half of the gas heating chamber of the drying chamber. The air inlet pipe communicates with the heat exchange outlet of the condensate heat exchanger. One end of the recovery pipe Connected to the top of the drying chamber, the other end of the recovery pipeline communicates with the reuse pipeline (8) through the bag filter, and the reuse pipeline communicates with the pre-heating pipeline, and the pre-heating pipeline is also arranged in the drying One side of the machine body is connected with half of the gas heating chamber of the pre-drying section heating chamber, one end of the exhaust gas discharge pipe is connected to the top of the pre-drying section heating chamber, and the other end of the exhaust gas discharge pipe is connected with the exhaust gas treatment system Pass. 2. A waste heat recovery mesh belt dryer according to claim 1, characterized in that: the top of the heating chamber of the pre-drying section is provided with a first diversion pipe (18), and the first diversion pipe (18) The pipeline communicates with the conveying chamber and is connected with the tail gas discharge pipe through the second guide pipe (19). The top of the conveying chamber of the heating chamber of the pre-drying section is also provided with a first blower for heating gas circulation. 3. A waste heat recovery mesh belt dryer according to claim 1, characterized in that: a third diversion pipe (21) is arranged on the top of the drying chamber, and the third diversion pipe is heated with the gas The chambers are connected and connected with the recovery pipe (15) through the fourth guide pipe, and the top of the gas heating chamber of the drying chamber is also provided with a second blower for heating gas circulation. 4. A waste heat recovery mesh belt dryer according to claim 1, characterized in that: the heating chamber of the pre-drying section and several gas heating chambers of the drying chamber are equipped with electric heating devices (11) . 5. A waste heat recovery mesh belt dryer according to claim 1, characterized in that: said tail gas treatment system is a spray absorption wet dust collector.

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