Closed MVR sludge drying device

Abstract

The invention relates to the field of sludge drying, and particularly discloses a closed MVR sludge drying device which is characterized in that a drying conveying belt, a heating roller, a roller scraper, a discharging mechanism and a discharging conveying belt are mounted in a box body, a spiral feeder is mounted on the left side of the upper end of the box body and communicates with the box body through a feeding disperser, and a discharging conveying belt is mounted in the box body. The discharge hole is formed in the left side of the lower end of the box body; two layers of heating rollers are arranged in the drying conveying belt, a roller scraper is installed between the heating rollers, and a discharging mechanism is arranged at the right end of the drying conveying belt. The right end of the upper portion of the box body is sequentially connected with the filter, the vacuum pump and the compressor, the compressor is connected with a steam inlet of the heating roller through the three-way valve and the movable and static connector, and a steam outlet of the heating roller is connected with the steam-liquid separator. According to the MVR sludge drying device, direct mass and heat transfer between sludge and heating steam can be well avoided, and the working efficiency of the MVR sludge drying device is improved.

Description

Technical Field

[0001] The invention relates to the field of sludge drying, and in particular to a closed sludge drying device based on the MVR principle. Background Art

[0002] Conventional sludge thermal drying technologies mainly include thin layer drying technology, disc drying technology, paddle drying technology, belt drying technology, etc. Among them, belt drying technology is different from other drying technologies. The heat medium passes through the sludge to achieve direct heat exchange with the sludge, thereby achieving the purpose of drying the sludge. The belt drying process is highly favored because it has the characteristics of no sticky stage, almost no dust, and little wear in the dryer. In addition, belt drying technology can also be used in combination with other drying technologies.

[0003] The sludge belt dryer can adapt to a variety of heat sources, especially can effectively utilize low-temperature and low-quality heat sources, such as hot water, waste heat flue gas, etc., thereby reducing operating costs; at the same time, the sludge belt dryer has the advantages of simple equipment structure, extremely low dust generation, safe operation and convenient product dryness adjustment.

[0004] The MVR principle is used for sludge drying, with low operating costs and significant energy-saving effects. However, the use of secondary steam to directly contact the sludge for heat and mass transfer can easily cause condensed liquid to directly enter the sludge, causing secondary moisture in the sludge, affecting the MVR drying effect and even preventing the drying process from proceeding normally.

[0005] In order to solve the above problems, the present invention designs a closed MVR sludge drying device. Summary of the invention

[0006] The present invention aims to solve the problem of secondary moisture of sludge caused by condensation of heating steam during sludge drying, and provides a closed MVR sludge drying device to improve the working efficiency of traditional belt dryers and MVR systems.

[0007] In order to achieve the above technical objectives, the present invention provides the following technical solutions: a closed MVR sludge drying device, characterized in that it includes a drying conveyor belt, a heating roller, a roller scraper, a three-way valve, a discharge conveyor belt, a discharge mechanism, a compressor, a vacuum pump, a filter, a screw feeder, a heating coil, a water pump, a gas-liquid separator, a discharge port, a box, a feed disperser, a dynamic and static joint and a transmission mechanism; the drying conveyor belt, the heating roller, the roller scraper, the discharge mechanism, and the discharge conveyor belt are installed inside the box, and the discharge conveyor belt is arranged at a certain distance below the drying conveyor belt; the screw feeder is installed The left side of the upper end of the box body is connected to the box body through the feed disperser; the discharge port is installed on the left side of the lower end of the box body; two layers of heating rollers are arranged inside the drying conveyor belt, a roller scraper is installed in the middle of the heating roller, and a discharge mechanism is arranged at the right end of the drying conveyor belt; the right end of the upper part of the box body is connected to the filter, vacuum pump and compressor in sequence, the compressor is connected to the steam inlet of the heating roller through a three-way valve and a dynamic and static joint, and the steam outlet of the heating roller is connected to the vapor-liquid separator; the upper part of the vapor-liquid separator is connected to the filter and the vacuum pump, and the lower part of the vapor-liquid separator is connected to the heating coil through a water pump.

[0008] Furthermore, the heating rollers are connected by pipelines to form multiple groups of configurations, dynamic and static joints are arranged at both ends of the heating rollers, and a transmission mechanism is arranged only at one end.

[0009] Furthermore, the discharging conveyor belt and the drying conveyor belt run in opposite directions.

[0010] Furthermore, a heating coil is arranged on the outer periphery of the screw feeder.

[0011] Furthermore, the discharge port is provided with a wing valve sealing structure.

[0012] Furthermore, the transmission sprockets include two, and the adjacent heating rollers are connected via a chain.

[0013] When the device is working, firstly, high-temperature steam is introduced as the starting steam through the three-way valve; the sludge enters the box through the screw feeder and is scattered on the drying conveyor belt through the feed disperser; the high-temperature steam enters the heating drum from the steam inlet of the heating drum assembly; the sludge transfers heat with the heating drum during the movement of the conveyor belt, and the water in the sludge evaporates into secondary steam. The secondary steam is cleaned, collected and heated through the filter, vacuum pump and compressor, and converted into high-temperature steam to replace the starting steam. The vapor-liquid mixture discharged from the steam outlet of the heating drum assembly is separated by the vapor-liquid separator, and the higher-temperature water is pumped to the heating coil on the periphery of the screw feeder through the water pump to fully recover the heat, and the low-temperature condensed water is discharged; the water vapor in the vapor-liquid separator is recycled together with the secondary steam. The sludge moves and dries with the conveyor belt, and a discharge mechanism is set at the right end of the drying conveyor belt to scrape off the dried sludge; during the rotation of the heating drum, the material on its surface is removed by the drum scraper; the fallen sludge is transported to the discharge port by the discharge conveyor belt. The sludge is continuously fed, forming a continuous sludge drying operation.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] (1) The secondary steam generated by sludge drying is mechanically recompressed to fully utilize the latent heat of vaporization of water vapor, realize the MVR drying process, and significantly reduce the operating costs of sludge drying.

[0016] (2) A heating drum is provided, and high-temperature steam flows inside the heating drum. The heat is transferred through the heating drum to heat the sludge, which can effectively solve the problem of secondary sludge moisture caused by steam condensation during the MVR sludge drying process.

[0017] (3) The heating rollers are connected by pipelines to form multiple groups of configurations, which can adjust the temperature range of the heating steam; a heating coil is arranged on the periphery of the screw feeder to fully utilize the heat of condensed water to increase the feed temperature, thereby improving the drying efficiency.

[0018] (4) The sealing structure of the screw feeder and the wing valve of the discharge port ensures the vacuum degree inside the box, and the sludge drying can be carried out continuously. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a front view structural schematic diagram of a closed MVR sludge drying device provided by the present invention;

[0020] Figure 2 It is a schematic diagram of a top view of a closed MVR sludge drying device provided by the present invention;

[0021] Figure 3 It is a schematic diagram of the heating roller assembly structure;

[0022] Figure 4It is a schematic diagram of the heating roller sprocket transmission mechanism;

[0023] Figure 5 It is a schematic diagram of the sealing structure of the wing valve at the discharge port;

[0024] Figure 6 The invention discloses a work flow chart of a closed MVR sludge drying device.

[0025] like Figure 1 to Figure 6 As shown, 1 is a drying conveyor belt, 2 is a heating roller, 3 is a roller scraper, 4 is a three-way valve, 5 is a discharging conveyor belt, 6 is a discharging mechanism, 7 is a compressor, 8 is a vacuum pump, 9 is a filter, 10 is a screw feeder, 11 is a heating coil, 12 is a water pump, 13 is a gas-liquid separator, 14 is a discharging port, 14.1 is a wing valve, 15 is a box body, 16 is a feed disperser, 17 is a dynamic and static joint, 18 is a transmission mechanism, 18.1 is a sprocket, and 18.2 is a chain. DETAILED DESCRIPTION

[0026] The technical solutions in the embodiments of the present invention are clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0027] like Figures 1 to 6 As shown, a closed MVR sludge drying device is characterized in that it includes a drying conveyor belt 1, a heating roller 2, a roller scraper 3, a three-way valve 4, a discharge conveyor belt 5, a discharge mechanism 6, a compressor 7, a vacuum pump 8, a filter 9, a screw feeder 10, a heating coil 11, a water pump 12, a gas-liquid separator 13, a discharge port 14, a box 15, a feed disperser 16, a dynamic and static joint 17 and a transmission mechanism 18; the drying conveyor belt 1, the heating roller 2, the roller scraper 3, the discharge mechanism 6, and the discharge conveyor belt 5 are installed inside the box 15, and the discharge conveyor belt 5 is arranged at a certain distance below the drying conveyor belt 1; the screw feeder 10 is installed on the left side of the upper end of the box 15, It is connected with the box body 15 through a feed disperser 16; the discharge port 14 is installed on the left side of the lower end of the box body 15; two layers of heating rollers 2 are arranged inside the drying conveyor belt 1, a roller scraper 3 is installed in the middle of the heating roller 2, and a discharge mechanism 6 is arranged at the right end of the drying conveyor belt 1; the upper right end of the box body 15 is connected with a filter 9, a vacuum pump 8, and a compressor 7 in sequence, the compressor 7 is connected with the steam inlet of the heating roller 2 through a three-way valve 4 and a dynamic and static joint 17, and the steam outlet of the heating roller 2 is connected with a vapor-liquid separator 13; the upper part of the vapor-liquid separator 13 is connected with the filter 9 and the vacuum pump 8, and the lower part of the vapor-liquid separator 13 is connected with the heating coil 11 through a water pump 12.

[0028] The heating rollers 2 are connected by pipelines to form multiple groups of configurations. Both ends of the heating rollers 2 are provided with dynamic and static joints 17, and only one end is provided with a transmission mechanism 18.

[0029] The discharging conveyor belt 5 runs in the opposite direction to the drying conveyor belt 1 .

[0030] A heating coil 11 is arranged on the outer periphery of the screw feeder 10 .

[0031] The discharge port 14 is provided with a wing valve 14.1 sealing structure.

[0032] The transmission sprockets 18.1 include two, and the adjacent heating rollers 2 are connected via a chain 18.2.

[0033] For one application condition, the sludge temperature is 85℃, the liquid evaporation temperature is 85℃, and the steam separated from the gas and liquid after drying is secondary steam, the boiling point rises by 5℃, and the secondary steam temperature is 80℃. The latent heat of vaporization absorption of the 85℃ liquid evaporation is 2302.86kJ / kg, the secondary steam compression work is 33.6kJ / kg, and the auxiliary power consumption of the evaporator is 10kJ / kg.

[0034] according to Figure 6 As shown, perform the following steps in sequence:

[0035] (1) The device is powered on and operated, and the sludge enters the box 15 through the screw feeder 10 and is evenly scattered on the drying conveyor belt 1 through the feed disperser 16.

[0036] (2) High-temperature steam is introduced as starting steam through the three-way valve 4. The high-temperature steam enters the interior of the heating drum 2 from the steam inlet of the heating drum 2 assembly. As the sludge moves along the drying conveyor belt 1, heat is transferred between the sludge and the heating drum 2. Water in the sludge evaporates into secondary steam. The secondary steam is cleaned, collected and heated by the filter 9, vacuum pump 8 and compressor 7, and then converted into high-temperature steam to replace the starting steam and enter the heating drum 2 to continue drying the sludge.

[0037] (3) The sludge moves along with the drying conveyor belt 1 and is dried. A discharge mechanism 6 is provided at the right end of the drying conveyor belt 1 to scrape off the dried sludge. During the rotation of the heating drum 2, the material adhering to the surface of the heating drum 2 is cleaned by the drum scraper 3. The fallen sludge is transported by the discharge conveyor belt 5.

[0038] (4) The dried sludge on the discharge conveyor belt 5 is sent to the discharge port 14.

[0039] (5) The vapor-liquid mixture discharged from the steam outlet of the heating drum assembly 2 passes through the vapor-liquid separator 13, and the water with higher temperature is pumped to the heating coil 11 on the periphery of the screw feeder 10 by the water pump 12 to preheat the feed and make full use of the heat. After the heat exchange is completed, the low-temperature condensed water is discharged; the vapor in the vapor-liquid separator 13 also flows through the filter 9, the vacuum pump 8 and the compressor 7 to increase the temperature and pressure, and serves as a heating heat source.

[0040] (6) The sludge is continuously fed to form a continuous sludge drying operation.

[0041] Compared with the steam-heated single-effect evaporation drying process, the closed MVR sludge drying device provided by this patent has high energy efficiency, only consuming compression work and auxiliary motion work, and the energy saving effect can reach 92%.

Claims

1. A closed MVR sludge drying device, characterized by: It includes a drying conveyor belt, a heating roller, a roller scraper, a three-way valve, a discharging conveyor belt, a discharge mechanism, a compressor, a vacuum pump, a filter, a screw feeder, a heating coil, a water pump, a vapor-liquid separator, a discharge port, a box, a feed disperser, a dynamic and static joint and a transmission mechanism; the drying conveyor belt, the heating roller, the roller scraper, the discharge mechanism and the discharging conveyor belt are installed inside the box, and the discharging conveyor belt is arranged at a certain distance below the drying conveyor belt; the screw feeder is installed on the left side of the upper end of the box and is connected to the box through the feed disperser; The discharge port is installed on the left side of the lower end of the box body; two layers of heating rollers are arranged inside the drying conveyor belt, a roller scraper is installed in the middle of the heating roller, and a discharge mechanism is arranged at the right end of the drying conveyor belt; the upper right end of the box body is connected with a filter, a vacuum pump, and a compressor in sequence, the compressor is connected with the steam inlet of the heating roller through a three-way valve and a dynamic and static joint, and the steam outlet of the heating roller is connected with a vapor-liquid separator; the upper part of the vapor-liquid separator is connected with a filter and a vacuum pump, and the lower part of the vapor-liquid separator is connected with a heating coil through a water pump.

2. A closed MVR sludge drying device according to claim 1, characterized in that: The heating rollers are connected by pipelines to form multiple groups of configurations. Both ends of the heating rollers are provided with dynamic and static joints, and only one end is provided with a transmission mechanism.

3. A closed MVR sludge drying device according to claim 1, characterized in that: The discharging conveyor belt and the drying conveyor belt run in opposite directions.

4. A closed MVR sludge drying device according to claim 1, characterized in that: A heating coil is arranged on the outer periphery of the screw feeder.

5. A closed MVR sludge drying device according to claim 1, characterized in that: The discharge port is provided with a wing valve sealing structure.

6. The heating roller transmission mechanism according to claim 2, characterized in that: It includes two sprockets of the same specification, and the adjacent heating rollers are connected by a chain.

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