JPS601080B2 - Sewage sludge thickening equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION When treating sewage sludge, it is important to remove water and thicken the sewage sludge in the first step.

Sewage sludge can be concentrated to a moisture content of 80% to 60% by mechanical treatment, but if the sewage sludge is further heated to evaporate the moisture and concentrated to a moisture content of 60% to 50%, then In this process, the capacity of the equipment can be reduced, and the process can be carried out very easily and smoothly. The present invention relates to a concentrator that is effective in treating sewage sludge with a relatively high moisture content of about 80%. [Prior Art] The present inventor has previously developed a sewage sludge incinerator shown in FIG.

The present inventor has also previously developed a sewage sludge supply device shown in FIGS. 2 and 3. The present invention is a sewage sludge thickening device that is used in place of the heater 3 in the sewage sludge incinerator shown in FIG. 1, and the sewage sludge supply device shown in FIGS. Since this is the sewage sludge thickening device used, before explaining the present invention, first, the sewage sludge incineration device shown in FIG. 1 and the sewage sludge supply device shown in FIGS. 2 and 3 will be explained. do.

In FIG. 1, sewage sludge with a moisture content of about 80% in a hopper 1 is first supplied to a sewage sludge heater 3 by a forced feeding means 2 and heated, and as a result of raising the temperature, its viscosity decreases. Sewage sludge drying furnace 4 with fluidized sand bed after being lowered
supplied to The drying oven is approximately 1 inch from the lower base of the sand layer.
A necessary amount of drying gas pressurized and heated to 20,000 to 40,000 °C is supplied to the water column, and this gas fluidizes the sand bed, so that the sewage sludge supplied to the sand bed from above flows through this fluidized sand bed. It is dried while being pulverized. The product produced in the drying oven 4 is sucked by a blower 11 and separated into a solid component and a gas component by a separating means 5. The solid content is dropped into a hopper provided below the separation means 5, and the powder supply means 6 provided at the bottom of the hopper.
The sewage sludge is supplied to the sewage sludge combustion furnace 7 in constant quantities. 1st
The combustion furnaces shown in the figure are an incomplete combustion furnace 7 and a complete combustion furnace 7'.
This is a two-stage combustion method, and by performing two-stage combustion in this way, the amount of NOx generated can be significantly reduced. The air necessary for these combustions is supplied by a blower 13 to the air heater 1 installed around the outer periphery of the complete combustion furnace 7'.
4 and is preheated, then distributed and sent to incomplete combustion furnace 7.
The products of the complete combustion furnace 7' are sucked in by a blower 10', pass through a heat exchanger 8, pass through a filter 9, and are exhausted by a blower 101. Further, the gas separated by the separation means 5 is transferred to a water column 100 by a blower 11.
It is pressurized to the level of the ship's side and circulated through the circulation piping 12,
The heat exchanger 8 is provided in the circulation path, and the heat exchanger raises the temperature from 200qo to 400o0. The amount of gas heated by the heat exchanger 8 is the sum of the amount A of gas supplied to the drying furnace 4 for drying and the amount B of gas generated from the sewage sludge supplied in the drying furnace 4. Of these total amounts, the same amount of gas as A and Ho) is again supplied to the drying oven 4 as the necessary drying gas, and the remaining gas, which is approximately the same amount as B, is used as heating gas. It is supplied to the heater 3 as a minute amount. After passing through the heater 3 and heating the sewage sludge, the gas passes through the drain separation means 15 and discharges the drain out of the system by the drain separation means, and then is supplied into the combustion furnace 7 through the gas supply pipe 16. Ru. Most of the sewage sludge gas produced by the drying furnace 4 is water vapor, and the remaining gas is passed through the heater and drained out of the system, and the remaining gas is supplied to the combustion furnace. It is possible to reduce the amount of water vapor present in the interior. The sewage sludge incinerator shown in Figure 1 has a sewage sludge with a relatively high moisture content of 80%, or dried sewage sludge, which can produce 3,500 Kca/kg of calories.
This incineration system is suitable for incinerating sewage sludge with a relatively low calorie of less than k9, and can perform incineration smoothly using only its own calories without almost requiring replenishment of fuel for incineration.

However, if water is removed as much as possible in the process of the first heater 3 and the sewage sludge is concentrated before being supplied to the drying furnace 4 and combustion furnace 7, these drying furnaces and combustion furnaces can be made smaller. In addition, sewage sludge can be treated smoothly. The apparatus shown in FIGS. 2 and 3 used in place of the supply means 2 in FIG. 1 has the following structure.

A take-out pipe 21 is provided at the bottom of a hopper for discharging sewage sludge, a piston 24 having a rotating body 22 and a connecting rod 23 is provided in a cylinder 25, a ball valve 26 is provided in a casing 27 at the tip of the cylinder 25, A curved passage 28 is provided in the ball valve 26, and an operating rod 29 is fixed to the ball valve 26, and the operating rod 29 rotates the ball valve 26 by the reciprocating motion of the piston 24. .

That is, when the piston 24 is retracted and in the suction state as shown in FIG.
As shown in FIG. 3, when the piston 24 moves forward and is in the extrusion state, the tip of the curved passage 28 in the ball valve 26 is structured to communicate with a supply pipe 30 for sewage sludge to the next process. The supply device shown in FIGS. 2 and 3 that intermittently sends sewage sludge under high pressure to the supply pipe 30 is a discharge pipe, and the sewage sludge in the pipe 30, which is a supply pipe to the next process, is shown in FIG. As shown, a certain high pressure is reached at one moment, and the pressure becomes 0 at the next moment, and intermittent advancement is performed while high pressure and 0 pressure are repeated.

That is, FIG. 4 shows the change in the pressure of the sewage sludge over time, with the vertical axis representing the pressure of the sewage sludge at the root position 31 of the supply pipe 30 and the horizontal axis representing time. The supplied sewage sludge has a pressure of 3 atm at one time and 0 at the next time, and is supplied while high pressure and 0 pressure are alternately repeated. FIG. 5 shows the change in pressure of the sewage sludge at the end position 32 of the supply pipe 30 over time.

[Configuration of the present invention]

The sewage sludge thickening apparatus of the present invention is equipped with several heating and dewatering units in the supply pipe 301.

Further, the sewage sludge thickening apparatus of the present invention employs the supply device shown in FIGS. 2 and 3, which has already been explained, in place of the supply means 2 in FIG. 1. The sewage sludge thickening device of the present invention will be explained with reference to FIGS. 6, 7, 8, and 9 showing embodiments thereof. Fig. 6 shows a sewage sludge thickening device equipped with only one set of three supply pipe heating and dewatering units for supplying sewage sludge by forcibly applying strong pressure intermittently, and Fig. 9 shows a sewage sludge thickening device that is equipped with only one set of three supply pipe heating and dehydrating units. As an example of a concentrator having two or more dehydration units, a sewage sludge concentrator having three dehydration units is shown. As shown in FIG. 6, the sewage sludge thickening device of the present invention uses a feeding device for intermittently feeding sewage sludge under high pressure, similar to the feeding devices shown in FIGS. 2 and 3.

For example, a take-out pipe 21 is provided at the bottom of a hopper containing sewage sludge, a piston 24 having a rotating body 22 and a connecting pipe 23 is provided in a cylinder 25, and a ball valve 26 is provided in a casing 27 at the tip of the cylinder 25. A curved passage 28 is provided in the ball valve 26, and an operating rod 29 is provided fixed to the ball valve 26, and the operating rod 29 rotates the ball valve 26 in conjunction with the reciprocating movement of the piston 24. let That is, as shown in FIG. 2, when the piston 24 is retracted and in the suction state, the tip of the curved passage 28 in the ball valve 26 is connected to the take-out pipe 21 at the bottom of the hopper 1, and as shown in FIG. As shown, piston 2
When the ball valve 4 moves forward and is in the extrusion state, the ball valve 26
The tip of the curved passage 28 is structured to communicate with a supply pipe 30 provided to supply sewage sludge to the next step, a drying furnace having a fluidized sand bed. When the supply pipe 301 is provided with one or several heating/dehydration units, the supply pipe 30 is provided with a heat conduction pipe 33 and a permeable porous pipe 34 connected thereto. A heating mantle chamber 35 is provided surrounding the heat conduction tube 33, and heating gas is supplied to the mantle chamber 36 from a heating gas supply pipe 37, as shown in FIG. As mentioned in the explanation of FIG. 1 above, the supplied gas is pressurized by the blower 11 to, for example, about 100 m2 of water, and is then compressed to 2 by the heat exchanger 8.
It is supplied in a heated state between 00q0 and 40000°C. Further, the heating mantle chamber 35 is provided with a take-out pipe 38 at its lower end, and the take-out pipe 38 is provided with a drain separating means 15, and the remaining gas after taking out the drain out of the system is transferred to the supply pipe 16.
For example, it is supplied to a combustion furnace.
A dehydration jacket chamber 36 is provided surrounding a permeable perforated tube 34 connected to the heat transfer tube 33 and provided downstream thereof, and as shown in FIG. 8, a suction tube 39 is provided at its lower end.
A cooling means 40 and a drain separating means 41 are provided, and the remaining gas after drain is taken out of the system is supplied to, for example, a combustion furnace through a supply pipe 16.

A cooling means 40 is provided and the mantle chamber 36 is cooled depending on the degree of cooling.
It is possible to create a considerable amount of negative pressure inside. Therefore, the gas generated by heating the sewage sludge can be sucked into the dewatering mantle chamber 36, and the sewage sludge in the supply pipe can be concentrated.
As shown in FIG. 9, a pressurization/dehydration unit is provided with a heating mantle chamber 35 surrounding a heat conduction tube 33 and a dehydration mantle chamber 36 surrounding a permeable perforated pipe 34 adjacent to each other in a sewage sludge supply pipe 30. Several sets can be provided. [Operations and Effects of the Present Invention] In the sewage sludge thickening device of the present invention, the pressure of the sewage sludge over time at the entrance position 3 of the above-mentioned heating/dehydration unit provided with 301 supply pipes is as shown in Fig. 4. , position 32 after passing through one or several heating and dewatering units, i.e. before being fed to a drying oven with a bed of fluidized sand.
Although the change over time in the pressure of the sewage sludge in the supply pipe 30 varies depending on the degree of concentration processing performed by the concentrator, it is as shown in FIG. 5, for example.

Water in the sewage sludge in the heat transfer pipe 33 does not evaporate easily under high pressure, and the temperature of the sewage sludge is raised to a high temperature. Moisture is actively vaporized and remains in the sewage sludge in a compressed gas state even when pressure is applied again, and when it is eventually transferred to the position of the permeable porous pipe 34, vaporization does not occur because the dewatering mantle chamber 36 is under negative pressure. The vaporized gas is collected into the dehydration jacket chamber 36.

As described above, the present invention provides a sewage sludge supply system in which high pressure and low pressure are repeated in the sewage sludge supply pipe 33, and a heating and
This device is characterized by its combination with a dewatering unit, and is particularly suitable for removing and concentrating water from sticky sewage sludge.

In particular, a low moisture content can be achieved by arranging several heating/dehydration units in series. For example, the dehydration effect of the conventional forced constant pressure supply under the condition that the temperature of the heating gas is 200 pm and the pressure of the dehydration mantle chamber is 1'2 atm. When compared, the amount of water removed in the present invention is about three times greater than that in the constant pressure supply method.

In the case of the present invention, it is easy to reduce the moisture content of sewage sludge from 80% to 60% by providing two to three heating/dehydrating units. With the combination of a screw conveyor and a heating dewatering unit, even if there are three units, it is difficult to reduce 80% water content of sewage sludge to 70% water content. While the sewage sludge passes through the thickening device of the present invention, a large amount of moisture is removed, the moisture content is reduced, the volume is reduced, and the sewage sludge is preheated, reducing the volume of the drying furnace and combustion furnace in the subsequent process to approximately 1/2 degree. It can be designed as small as possible and can be easily processed.

To make it possible not only to incinerate sewage sludge while smoothly replenishing fuel, but also to facilitate the recovery of useful resources such as fertilizer, gas fuel, and construction materials from sewage sludge. Moreover, the concentrating device of the present invention has a very simple structure, is easy to manufacture, and is easy to operate.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of a sewage sludge incinerator that was previously developed by the present inventor. FIGS. 2 and 3 are explanatory diagrams of a sewage sludge supply device previously developed by the present inventor and used in the sewage sludge thickening device of the present invention. Figures 4 and 5 are graphs showing changes over time in the pressure within the supply pipe of sewage sludge supplied by the supply devices shown in Figures 2 and 3. The figure shows the situation downstream of the supply pipe. Figures 6 and 9 are cross-sectional views showing the sewage sludge thickening device according to the present invention, in which Figure 6 shows a state in which one heating dehydration unit is used and Figure 9 shows a state in which three units are used. FIG. 7 and 8 are a W-skin sectional view and a skin-to-skin sectional view in FIG. 6, respectively. 21 is an extraction pipe, 22 is a rotating body, 23 is a connecting rod, 24 is a piston, 25 is a cylinder,
26 is a ball valve, 27 is a casing, 28 is a curved passage, 29 is an operating pipe, 30 is a supply pipe, 31 is a neck end position of the supply pipe, 32 is an end position of the supply pipe, 33 is a heat transfer pipe, 34
1 is a permeable porous pipe; 35 is a heating mantle; 36 is a moisture suction mantle; 37 is a heating gas supply pipe; 38 is an extraction pipe;
5 is a drain separation means, 16 is a gas supply pipe, 39 is a suction pipe, 40 is a cooling means, and 41 is a drain separation means. *1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9

Claims (1)

[Claims] 1. A sewage sludge supply device is provided that intermittently pushes sewage sludge under strong pressure into the supply pipe 30, and one or several heating/dehydration units are provided in the supply pipe 30, and these heating/dehydration units are used to push the sewage sludge into the supply pipe 30. The tube 30 is provided with a heat conduction tube 33 portion and an air permeable porous tube 34 portion following the heat conduction tube 33, and a heating jacket chamber 35 is provided which surrounds the heat conduction tube 33 portion and is connected to a heating gas supply tube 38. A sewage sludge concentrating device having a structure in which a dewatering mantle chamber 36 having a suction pipe 39 surrounding the permeable porous pipe 34 and leading to a cooling means 40 and a drain separation means 41 is provided.