KR102187379B1 - Bio sludge drying method and apparatus eliminated drying resistance - Google Patents

Abstract

The present invention relates to a microorganism sludge drying method removing drying resistance and, more specifically, to a microorganism sludge drying method comprising: a (1) dehydration step of collecting microorganisms grown in a water treatment process of a sewage treatment plant, dehydrating the same with a dehydrator, and discharging the same as solid microorganism sludge; (2) a first drying resistance removing step of forming osmotic pressure removing sludge by removing osmotic pressure, which is the cause of primary drying resistance formed by confining cell fluid of the microorganism constituting the microorganism sludge inside a cell membrane; (3) a secondary drying resistance removal step of forming mixed sludge to prevent secondary drying resistance generated by reducing an evaporation area by agglomeration with the viscosity of the osmotic pressure removing sludge; and (4) a drying step of drying the mixed sludge to form dry sludge.

Description

Bio sludge drying method and apparatus eliminated drying resistance {Bio sludge drying method and apparatus eliminated drying resistance}

The present invention relates to a method and a drying apparatus for drying microbial sludge from which drying resistance has been removed, and in particular, the present invention is a dehydration step of collecting microorganisms grown in a water treatment process of a sewage treatment plant and dehydrating them with a dehydrator to discharge them into microbial sludge having a solid shape. Wow, the first drying resistance removal step to make the osmotic pressure removal sludge by removing the osmotic pressure that is the cause of the primary drying resistance formed by trapping the cell fluid of the microorganisms constituting the microbial sludge inside the cell membrane, and the evaporation area due to the osmotic pressure removal sludge aggregated into viscous The drying resistance that can utilize microbial sludge as a resource is composed of a second drying resistance removal step of making mixed sludge that prevents the secondary drying resistance generated by reducing the pressure and a drying step of drying the mixed sludge to make the dried sludge. It relates to a method and a drying apparatus for drying the removed microbial sludge.

In the drying step, if dehumidification drying is performed in which the water vapor of the internal air circulating through the closed drying space is removed with condensed water using a heat pump, the evaporated water vapor is not discharged to the outside of the drying space, thus preventing the occurrence of odor and energy required for drying. Dry energy is saved by reusing energy that is recovered from steam and supplied again.

Microbial sludge is dehydrated as much as possible with a dehydrator that uses mechanical force such as filter or centrifugal force to eat organic matter and to remove the organic matter, which is a pollutant of dirty sewage or wastewater, in a sewage treatment plant. As a waste to be discarded, this microbial sludge maintains 80% moisture content by retaining the cell fluid of microorganisms, so 100 kg of microbial sludge contains only 20 kg of solid and 80 kg of water, so it cannot be used as a resource.

In order to be used as fuel for power plants, to dry with a moisture content of 10% or less, only 2.2 kg of water must be left in 80 kg of water, so drying is required to additionally remove 77.8 kg, which is more than 97% of the water held by microbial sludge.

However, 1 gram of this dehydrated microbial sludge is made up of more than 100 million cells, and these microbial cells trap cell fluid inside the cell membrane under osmotic pressure to generate primary drying resistance that hinders evaporation. Does not dry.

When the microbial sludge is heated to a high temperature by applying energy with a hot plate, hot air, or electromagnetic waves during the drying process to achieve strong drying, the osmotic pressure of the microbes disappears and the microbial cell fluid is released at once, increasing the fluidity and forming a lump during the drying process. In addition to significantly reducing the evaporation area, secondary drying resistance is generated that sticks to the drying machine and hinders drying.

In addition, the dehydrated microbial sludge becomes anaerobic immediately after being discharged, whereby anaerobic microorganisms proliferate from various protein enzymes present on the surface of microbial cells, decomposing and discharging this protein enzyme into a large amount of odor substances. It begins.

After a long period of time, anaerobic microorganisms decompose to the protein entrances that make up the cell membrane, and the second stage of decay proceeds, damaging the cell membrane and leaking to the cell fluid, resulting in a more severe odor and converting to malignant waste that generates leachate, a high-concentration wastewater. .

Efficient drying is required in order to utilize the microbial sludge, which is a malicious waste, as a resource, and for this purpose, drying is performed well by effectively solving the primary and secondary drying resistance of the microbial sludge, and no odor occurs during the drying process. In addition, a new drying method with low drying cost is needed.

If the microbial sludge is dried to a moisture content of 10% or less in this new way, it can be converted into an energy resource with carbon credits and used as fuel for power plants.

The problem to be solved of the present invention is to provide a method for drying microbial sludge that removes the drying resistance that prevents the evaporation of moisture by confining the cell fluid by the osmotic pressure of the microbes in the microbial sludge and eliminates the primary drying resistance that hinders drying by blocking heat transfer. will be.

Another problem to be solved of the present invention is that the microbial cell fluid is released at a time during the drying process to form a lump during the drying process, greatly reducing the evaporation area, and removing the secondary drying resistance that adheres to the machine and interferes with drying during the drying process. It is to provide a sludge drying method.

Another problem to be solved by the present invention is to provide a method for drying microbial sludge that eliminates drying resistance that reduces odor, which causes the most complaints in the microbial sludge drying process.

Another problem to be solved by the present invention is to provide a method for drying microbial sludge in which the latent heat of water vapor generated in the drying process is recovered by a heat pump and the drying resistance that can be used again as drying energy is removed.

In order to achieve the above-described problem, the present invention is a dehydration step of (1) collecting microorganisms grown in a water treatment process of a sewage treatment plant, dehydrating them with a dehydrator, and discharging them as solid microbial sludge; (2) a first drying resistance removing step of forming osmotic pressure removing sludge by removing the osmotic pressure, which is the cause of the primary drying resistance formed by trapping the cell fluid of the microorganism constituting the microbial sludge inside the cell membrane; (3) a secondary drying resistance removal step of forming mixed sludge to prevent secondary drying resistance generated by reducing the evaporation area by agglomeration with the viscosity of the osmotic pressure removal sludge; (4) drying step of drying the mixed sludge to form dry sludge; Includes.

In addition, the first drying resistance removing step includes a pressurizing step of pressurizing the microbial sludge with a pump and transferring it to a pipe; A heating step of heating microorganisms transferred to a heating unit connected to the pipe; A thermal storage step of storing the heated microorganisms in a thermal insulation tank connected to the heating unit to make osmotic pressure-removing sludge from which the osmotic pressure has been removed; Consists of

In addition, the heating unit includes an injection unit having one end connected to the pipe and the other end connected to a plurality of heating pipes; A discharge unit having one end connected to the heating pipe and the other end connected to the warming tank; Consists of; a heating container connected to the injection unit and the discharge unit and configured to surround the heating tube to heat the heating tube by putting water vapor into the inner space.

Here, the secondary drying resistance removal step includes a mixing step of mixing the osmotic pressure removal sludge and the dried sludge to produce a mixed sludge having a moisture content of 50% or less; It may consist of a molding step of making the mixed sludge into a noodle shape.

Here, in the step of drying the mixed sludge, static drying of drying the mixed sludge on a moving belt may be performed and then dynamic drying of drying inside a rotating cylinder.

Here, in the second drying resistance removal step, a mixed sludge obtained by mixing at least one of coco peat and sawdust into the osmotic pressure removal sludge may be made.

Here, it further comprises a transport step between the dehydration step and the first drying resistance removing step, the transport step is a discharge step in which the microbial sludge is discharged from the dehydrator to the transport container; A truck moving step of moving the transport container to a drying facility away from the dehydrator of the sewage treatment plant by a truck; It may include a suction step of supplying the transport sludge contained in the transport container to the first drying resistance removal step and suctioning at negative pressure using a hose pump to make the osmotic pressure removal sludge.

Here, the drying step is a first drying step of drying the moisture content of the dried sludge between 25% and 35%; A second drying step of drying the dried sludge formed after the first drying step with fuel sludge having a moisture content of 10% or less; Can be made with

Here, a pellet forming step of forming the dried sludge into pellets between the first drying step and the second drying step; may be added.

In the apparatus for drying microbial sludge according to the present invention, the drying step is performed in a closed device, and dehumidification of water vapor of the air inside the device is performed simultaneously with drying, and the closed device includes an evaporation space in which moisture from the mixed sludge is evaporated and incorporated into the internal air. A heating unit divided into a dehumidifying space that cools the internal air and dehumidifies it with condensed water, and supplies dry energy by heating the internal air of the evaporation space; And a cooling unit for cooling the internal air introduced into the dehumidifying space, wherein the heating unit is composed of a heat pump condenser, and the cooling unit is composed of a heat pump evaporator.

Here, the sealing device increases the relative humidity of the internal air moving from the evaporation space to the dehumidification space to facilitate dehumidification in the dehumidification space, and the relative humidity of the internal air moving from the dehumidification space to the evaporation space so that evaporation occurs well in the evaporation space. A relative humidity conversion unit capable of lowering the value; Further comprising a blowing unit for allowing the internal air to pass through the relative humidity conversion unit, the relative humidity conversion unit, the liner member in the shape of a flat plate; A spacer member that is folded to form a valley and is attached to one side of the liner member to form a passage for internal air; And a plurality of conversion elements in which the liner member and the spacer member are stacked in multiple stages so that the directions of the air passages of the spacer member are continuously crossed with each other.

In the method of drying microbial sludge from which drying resistance is removed according to the present invention, the first drying resistance of microbial sludge, which prevents the evaporation of moisture by first removing the osmotic pressure of microorganisms by heating to a high temperature before drying, is removed before drying, and then drying and drying. In the process, evaporation proceeds easily even at a low temperature of 60° C. or less, and there is an advantage of reducing drying energy and drying time.

In the method of drying microbial sludge from which drying resistance has been removed according to the present invention, the osmotic pressure is removed before drying so that the viscous osmotic pressure-removing sludge does not form a lump in the drying process or stick to the machine, resulting in a secondary drying resistance that decreases the evaporation area. Thus, it is advantageous to reduce drying energy and drying time by maintaining the evaporation area as it is during the drying process by making it into a mixed sludge mixed with dry sludge, coco peat, or biomass such as sawdust in the osmotic pressure removal sludge with improved fluidity.

In the method for drying microbial sludge from which drying resistance is removed according to the present invention, not only the odor generated from the existing microbial sludge is reduced by removing anaerobic microorganisms that generate odor in advance, but also the water vapor generated during the drying process by dehumidifying using a closed space. As it does not leak out at all, there is an advantage that odors are not discharged to the outside during the drying process.

In the method of drying microbial sludge from which the drying resistance has been removed according to the present invention, when the drying resistance is removed, evaporation is easily performed even at temperatures below 60℃ during the drying process. It has the advantage of reducing drying costs by increasing energy efficiency by three times or more by recovering latent heat by condensing water vapor evaporated from sludge and supplying it as dry energy by making air into hot air of 60℃.

1 is a flow chart of the steps of the first embodiment of the present invention.
2 is a diagram showing a change in moisture content according to drying of microbial sludge
3 is a perspective view of a belt of a dehumidifying drying facility.
4 is a cylindrical cross-sectional view of a dehumidifying drying facility
5 is a flow chart of the steps of the second embodiment of the present invention.
6 is a block diagram of a hose pump.
7 is a block diagram of a dehumidification drying facility using a heat pump
8 is a perspective view of a relative humidity conversion device in a dehumidification drying facility.

Hereinafter, with reference to the accompanying drawings will be described in detail the sludge drying apparatus of the present invention to remove the drying resistance.

1 is a block diagram of a first embodiment of a sludge drying apparatus with no drying resistance. In the present invention, (1) microorganisms (A) grown in the water treatment process of a sewage treatment plant are collected and dehydrated with a dehydrator, and microbial sludge having a solid shape (B. ) And (2) the osmotic pressure removal sludge (C) is formed by removing the osmotic pressure that is the cause of the primary drying resistance formed by trapping the cell fluid of the microorganisms constituting the microbial sludge (B) inside the cell membrane. Drying resistance removal step and (3) secondary drying resistance removal step of making mixed sludge (D) to prevent secondary drying resistance that occurs by reducing the evaporation area by agglomeration with the viscosity of the osmotic pressure removal sludge (C) and (4) It consists of a drying step of drying the mixed sludge (D) to make dry sludge (E).

Currently, more than 11,000 tons of microbial sludge is generated every day in Korea's sewage treatment plant and is discarded as waste. If the microbial sludge is dried to a moisture content of 10% or less, it can be supplied to power plants as fuel with carbon credits.

Microbial sludge is a microbial mass that collects microorganisms that have grown in the process of removing organic matter, which is a pollutant of sewage or wastewater, and the composition of microorganisms changes depending on the water treatment method, so the moisture content of the microbial sludge varies between 70 and 85%, but the principle is explained here. To do this, the moisture content is assumed to be 80%.

In 100 kg of microbial sludge with a moisture content of 80%, only 20 kg of solid content and 80 kg of water are contained, as well as the cell fluid of more than 100 million microscopic cells in 1 g of this water, which prevents the evaporation of the cell fluid by the cell membrane and osmotic pressure. First drying resistance occurs.

In the existing drying method, because of this primary drying resistance, high-temperature drying energy of 100°C or higher is used. When the high-temperature drying energy is used in the drying process, the osmotic pressure of microorganisms in the drying device disappears at once and the cell fluid is released at once. The evaporation area rapidly decreases as the evaporation area rapidly decreases due to the formation of a liquid and viscous form, resulting in a secondary drying resistance that rapidly delays evaporation, and the dried sludge adhering to the drying machine from the secondary drying resistance to viscosity and dried is hard physical properties. It may wear parts and cause the machine to stop working.

Due to these two drying resistances consisting of the first drying resistance and the second drying resistance, microbial sludge takes a long time to dry in the drying process, so drying costs are excessive because it must use an enormous drying energy 3 times or more of the theoretical evaporation energy. In addition, the drying facility of microbial sludge is recognized as a hate facility by releasing extreme odors during storage, transportation, and drying, and can lead to many civil complaints.

In the present invention, two different drying resistances are separated and solved to suit the respective drying resistance characteristics through a pretreatment process prior to drying, and in order to solve this stepwise, the osmotic pressure of the microorganisms constituting the microbial sludge (B) The primary drying resistance removal step of making osmotic pressure removal sludge (C) that is removed at a temperature of 90°C and drying well at temperatures below 60°C, and the osmotic pressure removal sludge generated by viscosity and liquefaction when the osmotic pressure is removed, as the cell fluid flows out. To remove the secondary drying resistance of (C), the osmotic pressure-removing sludge with a moisture content of 80% is mixed with the dry return sludge (E1) to form a mixed sludge (D) with a moisture content of about 50% to prevent viscosity and liquefaction from occurring. It is configured to perform the drying resistance removal step.

Through the present invention, if the drying resistance is removed before drying and dehumidifying drying is performed, the outflow of odors is fundamentally blocked, and the occurrence of civil complaints that cause the greatest difficulty in drying microbial sludge can be prevented. have. In addition, through dehumidifying drying, it is easy to configure COP (Coefficient of Performance), which is the ratio of input energy and produced heat, which shows energy efficiency of the heat pump to 3.0 or more, so that drying energy can be greatly reduced.

The first drying resistance removal step is a pressurization step of pressurizing microbial sludge with a pump and transferring it to a pipe, a heating step of heating the microorganisms transferred to a heating unit connected to the pipe, and storing the heated microorganism in a heat retention tank connected to the heating unit. It may consist of a thermal storage step of making osmotic pressure-removing sludge from which the osmotic pressure has been removed.

One end of the heating unit used here is connected to a pipe and the other end is an injection part connected to a plurality of heating pipes, a discharge part connected to a heating pipe and one end connected to a warming tank, and a heating pipe connected to the injection part and discharge part. It is composed of a structure surrounding the inner space can be composed of a heating vessel that heats the heating tube by putting water vapor.

The structure of such a heating unit is a method widely used in a heat exchanger using steam and is well known to those skilled in the art, so a detailed description of the structure will be omitted.

Through this heating unit, the microbial sludge is heated to 90°C or higher and stored at a temperature of 90°C or higher in a connected thermal tank to reliably remove the osmotic pressure.

In addition, the thermal insulation tank can play a role of controlling the difference in the treatment speed of the drying facility after the step of removing the first drying resistance. Normally, drying facilities evaporate at a constant rate and operate continuously for 24 hours, but the primary drying resistance removal facility treats a large amount of sludge at one time when it is transported, so the amount of water treated at one time in a thermal insulation tank composed of an appropriate size and quantity It is possible to efficiently resolve the difference in speed between the two facilities by continuously supplying them to the drying facilities for 24 hours while storing them.

The secondary drying resistance removal step is a mixing step of mixing the osmotic pressure removal sludge (C) and the dry return sludge (E1) to form a mixed sludge (D) having a water content of 50% or less, and the mixed sludge (D) to form a noodle shape. It consists of a molding step, and in the drying step, static drying is performed on the belt 425 that moves the mixed sludge (D), and then the dry sludge (E) is formed by performing dynamic drying that is dried inside the rotating cylinder 426. can do.

When calculated by the degree of moisture content change according to drying of the microbial sludge shown in FIG. 2, when the dry return sludge (E1) having a moisture content of 30% and the osmotic pressure-removing sludge (C) having a moisture content of 80% are mixed in a ratio of 1.5:1.0, the moisture content is 50%. The mixed sludge (D) of is made, and 100 kg of the mixed sludge (D) made in this way is in the same state that 150 kg of water is dried in 200 kg of water with 250 kg of the osmotic pressure-removing sludge (C) with a moisture content of 80% and only 50 kg remains.

The osmotic pressure-removing sludge (C) has significantly improved fluidity compared to the microbial sludge (B), so it can be easily mixed with the dry return sludge (E1), and 100 kg of the osmotic pressure-removing sludge (C) with a moisture content of 80% is transferred to dry with a moisture content of 30%. Mixing with 150 kg of sludge (E1) to make 250 kg of mixed sludge (D) with a water content of 50% and drying it to 30% of moisture content makes 178.6 kg of dry sludge, of which 150 kg is divided into dry conveyed sludge (E1), and then dried again. Send it to the resistance removal step and discharge 28.6 kg of dry sludge (E) with a moisture content of 30%.

If 100 kg of microbial sludge (B) with a moisture content of 80% is dried, 28.6 kg of dry sludge (E) with a moisture content of 30% is equally secured, but drying energy and drying time are reduced by removing the primary and secondary drying resistance. It greatly reduces and minimizes the occurrence of odor.

Since the mixed sludge (D), which has removed the secondary drying resistance, maintains the evaporation area as it is, the evaporation of moisture proceeds very easily. Therefore, the heat pump is used to simultaneously supply dry energy required for evaporation and recover latent heat through condensation of water vapor. As a result, it is possible to easily perform dehumidification drying using the heat pump and internal air circulating in the closed internal space.

3 is a perspective view of the belt 425 of the drying facility, and FIG. 5 is a sectional view of the cylinder 426 of the drying facility.

The mixed sludge (D) is made into a noodle shape so that the evaporation area is secured as much as possible to facilitate evaporation, and statically dried so that the surfaces of each other do not initially stick on the belt 425 can be dried from the surface first. At this time, the belts 425 are stacked and arranged in the vertical direction, and both ends are formed to protrude from each other so that the static drying time is increased while stably moving from the upper side to the lower side. Through this, it is possible to induce a sufficient dry state before dynamic drying to be described later, thereby increasing the effect of the dry state. Then, while passing through the inside of the rotating cylinder 426, free fall in the inside of the cylinder 426 is dried so that dry energy transfer and evaporation occur quickly.

In addition, the secondary drying resistance removal step may be constituted by a method of making a mixed sludge (D) in which the osmotic pressure removal sludge and biomass such as coco peat or sawdust are mixed.

The removal of the secondary drying resistance is a process of lowering the moisture content to 50% or less so that there is no problem of liquefaction or viscosity in order to prevent the phenomenon that drying is delayed due to the reduction of the evaporation area during the drying process. To this end, dry return sludge to the osmotic pressure removal sludge (C). (E1) is mixed or biomass is mixed.

The material that can be mixed to dry the microbial sludge and use it as a fuel for a power plant is biomass such as coco peat or sawdust, so mix this material to make mixed sludge with the moisture content lowered to 50% or less to remove secondary drying resistance.

Next, in the second embodiment of the present invention using FIG. 6, the sewage treatment plant and the drying facility are separated, and a transport step of storing microbial sludge in a transport container as transport sludge 210 and transporting it to the drying facility by a truck is added, and the drying step is performed. This is a method of dividing into a first drying step and a second drying step, and adding a pellet forming step to make the dried sludge (E) into pellet sludge (F) and supply it to the fuel sludge (G) of the power plant.

In the second embodiment, the process of making the mixed sludge (D) with the secondary drying resistance removed is the same as in the first embodiment, and in the drying step, the mixed sludge (D) is put into a drying device to reduce the moisture content of the dried sludge (E). A first drying step of drying between 25% and 35%, a pellet forming step of molding dried sludge into pellet sludge (F), and a second drying step of drying pellet sludge (F) with fuel sludge (G) having a moisture content of 10% or less. It is configured to consist of a drying step.

When microbial sludge generated in the existing daily treatment plant is discharged from the dehydrator, it is placed in a transport container and transported to the transport sludge 210 to the treatment plant using a truck. In order to use the microbial sludge generated in the existing sewage treatment plant, a transport step is added between the dehydration step and the first drying resistance removal step, and the transport step includes a discharge step in which the microbial sludge (B) is discharged from the dehydrator to the transport container. , A truck moving step of moving the transport container to a drying facility away from the dehydrator of the sewage treatment plant by a truck, and suctioning at negative pressure using a hose pump 250 to supply the transport sludge 210 contained in the transport container to the drying facility. It is configured to consist of an inhalation step.

The hose pump 250 shown in the configuration diagram of the hose pump of FIG. 2 is shown as a device that sucks a highly viscous material with a vacuum using a hose made of a material restored to a circular shape even under vacuum pressure and transfers it to a high pressure of about 10 atmospheres. As shown, a rotating body 254 coupled to and interlocked with the rotating shaft 255 of the driving motor driven by the supply of power, and a compression shoe formed outside the rotating body 254 to give a compressive force to the hose 257 253, the compression shoe 253 and the casing 256 provided on the outside of the rotating body 254, etc., and both ends of the suction port 251 and the discharge port 252 of the hose 257 It is finished with a flange and has a structure that is connected to related pipes.

With this hose pump 250, the transport sludge (B1) contained in the transport container can be easily sucked by the suction power of the vacuum and supplied to the heating unit to remove the primary drying resistance to make the osmotic pressure removal sludge (300). It eliminates the need for expensive hopper facilities and minimizes the installation of odor prevention facilities, thereby improving the economy and utilization of site space.

In addition, if the condensed water generated during the drying process is transported back to the sewage treatment plant using a transport container and a truck for water treatment, the drying facility does not treat wastewater, so there is no need for a wastewater treatment facility. Configurable.

Dried sludge (E) dried with a moisture content of 30% reduces microbial sludge (200) with a moisture content of 80% to 28.6%, which reduces the amount of discharge and can greatly reduce the cost of waste disposal through landfilling. It has an advantage that it can be used as energy with carbon credits if it is dried with a water content of 10% or less and supplied as power plant fuel.

In particular, drying up to 30% moisture content evaporates well and drying is relatively easy, but drying with a moisture content less than 10% evaporates slowly and generates a lot of dust, making it difficult to dry, so the drying step is dried between 25% and 35% moisture content. It is efficient to configure the device to suit the drying characteristics at each step by consisting of a first drying step and a second drying step of drying with a moisture content of 10% or less.

In addition, in the process of compressing at high pressure in the process of making pellets, the pellets are heated to high temperature and moisture evaporates considerably, so the dried sludge (E) with a moisture content of 30% is made of pellet sludge (F) with a moisture content of 15% and this pellet sludge ( F) has many voids and can minimize dust generation, so that the second drying step can be easily performed in the storage silo.

When explaining the process of the second drying step of additionally drying the pellet sludge (F), the storage silo for storing the pellet sludge (F) is used as a drying space to perform dehumidification drying using a second heat pump, and the pellet sludge ( It is a configuration in which the latent heat of water vapor generated in the drying process of F) is recovered by a second heat pump, and the air is heated and supplied as drying energy.If the moisture content is lowered to 10% or less by additional drying of the pellet sludge (F), The calorific value is greatly increased and the odor is reduced to make high-quality fuel sludge (G).

In the present invention, the drying step of drying the mixed sludge (D) is performed in the closed device 400, and dehumidification of water vapor of the air inside the device is performed simultaneously with drying.

To this end, a dehumidification drying process will be described using a configuration diagram of a dehumidification drying facility using a heat pump of FIG. 7.

The dehumidification drying facility is a closed device 400 in the drying step, where the moisture of the mixed sludge D becomes steam and is incorporated into the internal air 411 by cooling the evaporation space 420 and the internal air 411 to dehumidify it with condensed water. It is divided into a dehumidifying space 430, a heating unit 422 that heats the internal air 411 of the evaporation space 420 to supply dry energy, and the mixed sludge with internal air heated in the evaporation space 420 ( D) includes an evaporation unit 421 that evaporates water into steam, a cooling unit 431 that cools the internal air 411 introduced into the dehumidification space 430, and the heating unit 422 is a heat pump condenser Consisting of 444 and the cooling unit 431 is composed of a heat pump evaporator 442.

The sealed drying space 410 is divided into an evaporation space 420 and a dehumidification space 430, and the internal air 411 is heated in the evaporation space 420 to lower the relative humidity to convert the moisture of the mixed sludge D into water vapor. It evaporates and cools the internal air in the dehumidifying space 430 so that the relative humidity is below the saturated state, and the water vapor is dehumidified with condensed water to remove moisture from the mixed sludge D.

In addition, if a heat pump 440 that simultaneously heats and cools the internal air 411 is used in this process, an efficient device for saving energy can be configured. The heat pump 440 compresses the refrigerant with the compressor 441 A high-temperature, high-pressure gas is produced and converted into liquid in the condenser 444 of the heating unit 422, and high-temperature energy is released to supply dry energy to the internal air 411 through the heating fan 423, and the valve 443 is opened. Gina is made into a liquid in a low temperature and low pressure state, and is converted to gas in the evaporator 442 of the cooling unit 431, absorbs energy at a low temperature to dehumidify water vapor, and the condensed water is discharged through the drain 432.

As the evaporation unit 421, the belt 425 of FIG. 4 and the cylinder 426 of FIG. 5 may be used.

The sealing device of such a dehumidification drying facility increases the relative humidity of the internal air 411 moving from the evaporation space 420 to the dehumidification space 430 so that dehumidification in the dehumidification space 430 is well performed, and in the evaporation space 420 The relative humidity conversion unit 450 and the internal air to lower the relative humidity of the internal air 411 moving from the dehumidification space 430 to the evaporation space 420 so that evaporation is well performed and the internal air pass through the relative humidity conversion unit 450 It further includes a blowing unit 460 to allow a plurality of conversion elements 451 to be installed in the relative humidity conversion unit 450, and the conversion elements 451 are folded with a flat plate-shaped liner member 452 The spacer member 453 which is attached to one side of the liner member 452 while forming a valley to form a passage for the internal air 411, and the liner member 452 so that the directions of the air passages of the spacer member 453 continue to alternate with each other. ) And the spacer member 453 are stacked in multiple stages.

FIG. 8 is a perspective view of the conversion elements of the relative humidity conversion unit. In FIG. 7, only two conversion elements 451 are shown. If necessary, more conversion elements may be connected to each other.

In this case, the conversion element is arranged vertically so as to form a flow path in a direction alternated with each other while a plurality of panels forming a plurality of flow paths are stacked along one direction. Therefore, it is possible to implement the inflow path (A) and outflow (B) structures at a time through one stacked structure, the structure can be made more compact, there is a characteristic that can be stably induced.

If a plurality of conversion elements 451 are configured, even if the temperature difference between the evaporation space 420 and the dehumidification space 430 is large, energy loss can be reduced and the amount of dehumidification can be increased by using the relative humidity conversion unit 450. For example, The internal air temperature of the evaporation space 420 can be effectively dehumidified by easily maintaining the dehumidification space 430 below 0°C even when the relative humidity is less than 10% at 60°C or higher, and the drying energy is 1kwh per 1kg of moisture removal. It creates an excellent energy saving effect that can be dried using less energy below.

In general, when comparing the energy required for drying microbial sludge, 1 ton of microbial sludge (B) with a moisture content of 80%, 1000 kg, contains 200 kg of organic matter and 800 kg of water, and evaporation of 1 kg of water requires 540 kcal of vaporization energy, so the moisture content is less than 10%. In order to evaporate 780kg to make fuel sludge (G), a total of 420,000 kcal of thermal energy is theoretically required. However, in the actual drying process, drying energy of more than 1 million kcal, which is more than twice this energy as drying resistance, is used, and in severe cases, there are drying devices that use energy of more than 2 million kcal.

In the sludge drying apparatus with the drying resistance removed of the present invention, 778 kg of water is evaporated from the drying resistance removal unit without drying resistance in the drying unit, so if the drying energy is recycled with a heat pump with a performance coefficient of 3 and 830 kcal per 1 kwh is applied, the heat pump will 253 kwh of electricity is required, and all of the electricity required to remove the drying resistance is added to dry the microbial sludge (B) with fuel sludge (G) by performing all drying to 400 kwh or less even if all electricity is included. When this 400kwh is converted into calories, it is 332,000kcal, which can dry the sludge with 1/3 less energy than 1 million kcal of energy used in the existing drying device.

As described above, the present invention is not limited to the specific preferred embodiments described above, and various modifications are implemented by those of ordinary skill in the art without departing from the gist of the present invention claimed in the claims. It is possible and such modifications are within the scope of the present invention.

A: microbial B: microbial sludge
B1: moving sludge 250: hose pump
C: Osmotic pressure removal sludge D: Mixed sludge
410: drying space 425: belt
426: cylinder 451: conversion element
E: Dry sludge E1: Dry return sludge
F: pellet sludge G: fuel sludge

Claims (11)

A dehydration step of collecting microorganisms grown in a water treatment process of a sewage treatment plant, dehydrating them with a dehydrator, and discharging them into a solid microbial sludge;
A first drying resistance removing step of forming osmotic pressure removing sludge by removing the osmotic pressure, which is a cause of the primary drying resistance formed by confining the cell fluid of the microorganism constituting the microbial sludge inside the cell membrane;
A secondary drying resistance removing step of forming mixed sludge to prevent secondary drying resistance generated by reducing the evaporation area due to liquefaction and viscosity of the osmotic pressure removing sludge;
Includes; a drying step of drying the mixed sludge to form dry sludge,
The first drying resistance removing step,
A heating step of heating the microbial sludge with a heating unit; And
Including; a thermal storage step of storing the heated microbial sludge in a thermal insulation tank connected to the heating unit to make the osmotic pressure removing sludge from which the osmotic pressure has been removed; and removing the osmotic pressure of the microorganisms constituting the microbial sludge to 90°C to 60 After making an osmotic pressure-removing sludge with a moisture content of 80% so that it can be dried well even below °C, store it in a thermal insulation tank at 90 °C or higher,
The secondary drying resistance removing step,
A mixing step to make the mixed sludge by mixing the osmotic pressure removal sludge formed in the first drying resistance removal step and the dried return sludge returned from the dried sludge produced in the drying step; And
A molding step of securing an evaporation area so that the mixed sludge can evaporate well; and the osmotic pressure-removing sludge having a moisture content of 80% is mixed with the dry return sludge to form a mixed sludge having a moisture content of 50% to prevent the occurrence of viscosity and liquefaction. Microbial sludge drying method to remove drying resistance, characterized in that. delete delete The method of claim 1,
The mixed sludge,
Microbial sludge drying method to remove drying resistance, characterized in that the water content is formed into a noodle shape so that the water content is 50% or less so that liquefaction and viscosity problems caused by the secondary drying resistance do not occur. The method of claim 1,
In the step of drying the mixed sludge,
A method for drying microbial sludge from which drying resistance is removed, characterized in that the mixed sludge is statically dried on a moving belt and then dynamically dried in a rotating cylinder. The method of claim 1,
The secondary drying resistance removing step,
Microbial sludge drying method to remove drying resistance, characterized in that to make a mixed sludge in which at least one of coco peat and sawdust is mixed with the osmotic pressure removal sludge instead of the dried sludge. The method of claim 1,
Further comprising a transport step between the dehydration step and the first drying resistance removing step,
The conveying step,
A discharge step in which the microbial sludge is discharged from the dehydrator to a transport container;
A truck moving step of moving the transport container by a truck to a drying facility away from the dehydrator of the sewage treatment plant;
A suction step of supplying the transport sludge contained in the transport container to the first drying resistance removal step and suctioning at negative pressure using a hose pump to make the osmotic pressure removing sludge; microbial sludge removing drying resistance comprising: Drying method. The method of claim 1,
The drying step,
A first drying step in which the moisture content of the dried sludge is between 25% and 35%;
A second drying step of drying the dried sludge formed after the first drying step with fuel sludge having a moisture content of 10% or less; Microbial sludge drying method, characterized in that consisting of, drying resistance is removed. The method of claim 8,
A pellet forming step of forming the dried sludge into pellets between the first drying step and the second drying step; Microbial sludge drying method to remove drying resistance, characterized in that is added. In the microbial sludge drying apparatus for drying microbial sludge from which drying resistance has been removed by applying to any one of claims 1 and 4 to 9,
The drying step is performed in a closed device, and steam dehumidification of the air inside the device is performed simultaneously with drying,
The sealing device is divided into an evaporation space in which moisture of the mixed sludge is evaporated and incorporated into the internal air, and a dehumidification space in which the internal air is cooled and dehumidified with condensed water,
A heating unit for supplying dry energy by heating the internal air of the evaporation space; And a cooling unit for cooling internal air introduced into the dehumidifying space,
The heating unit is composed of a heat pump condenser,
The cooling unit is composed of a heat pump evaporator,
The sealing device increases the relative humidity of the internal air moving from the evaporation space to the dehumidification space to facilitate dehumidification in the dehumidification space, and moves from the dehumidification space to the evaporation space to facilitate evaporation in the evaporation space. A relative humidity conversion unit capable of lowering the relative humidity of the internal air;
Further comprising a blowing unit to allow the internal air to pass through the relative humidity conversion unit,
The relative humidity conversion unit,
A flat plate-shaped liner member;
A spacer member that is folded to form a valley and is attached to one side of the liner member to form a passage for internal air; And
And a plurality of conversion elements in which the liner member and the spacer member are stacked in multiple stages so that the direction of the air passage of the spacer member continuously crosses each other. delete

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