JPS62800Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to the improvement of a digestion tank.

Large-scale digestion tanks are generally equipped with steam-injection type heating means and sludge gas agitation means to facilitate extinguishing fires. However, in conventional digesters of this type, the steam blowing pipe, the stirring gas blowing pipe, and the sludge feeding pipe are each installed independently without any connection with the others, and therefore, the steam blowing pipe, the stirring gas blowing pipe, and the sludge feeding pipe are installed independently, so that they are fed and cooled. The sludge caused by the sludge may cause the temperature in the tank to become uneven, reducing thermal efficiency, or the steam may directly heat the sludge contained during digestion, causing the death of microorganisms due to the heat. There are many problems in terms of efficiency.

This idea heats the sludge when it is introduced and digests it by inserting and opening a sludge inlet pipe, a steam blowing pipe, and a stirring gas blowing pipe into a draft tube suspended in the tank. The purpose of this invention is to solve the above-mentioned problems by stirring and mixing it into the sludge inside, and to provide a digestion tank with good thermal efficiency, mixing and stirring efficiency, and high digestive capacity.

Hereinafter, embodiments of this invention will be described with reference to the drawings.

In the figure, reference numeral 1 denotes a digester main body, and a large-diameter draft tube 2 is supported by a stay 3 and erected in the center of the main body. A sludge input pipe 4 is inserted into the opening 4a in the upper center of the draft tube 2 through the ceiling 1a of the main body 1, and a guide pipe 4b having a slightly larger diameter than the input pipe 4 is inserted downward into the opening 4a. is provided. A steam blowing pipe 5 for heating is inserted into the sludge input pipe 4 through a part of its wall, and its lower end is connected to the draft tube 2.
An opening 5a is provided at the center of the lower part of the opening 5a. Further, on the outside of the sludge input pipe 4, that is, in the gap 6 between the guide pipe 4b and the draft tube 2, a plurality of stirring gas supply pipes 7, 7 are provided at required intervals in the circumferential direction.
is inserted through the ceiling portion 1a of the tank body, and the gas discharge portion 7a at the lower end thereof is located at an intermediate portion between the upper and lower sides of the draft tube 2.

Next, the operation of the digestion tank configured as above will be explained. During normal operation of the digester, stirring gas is sent from the gas feed pipe 7 and is ejected from its discharge portion into the draft tube 2 and rises.
Due to the upward force of this ejected gas, the liquid in the tank is circulated as shown by the dotted arrow. At this time, heating steam is supplied from the steam blowing pipe 5 and is ejected into the liquid from the opening 5a. As a result, the circulating fluid passing through the draft tube 2 is heated as a whole and flows out from the upper part of the draft tube 2 into the tank. On the other hand, sludge newly supplied into the tank is supplied into the upper part of the draft tube 2 through the sludge input pipe 4, but since it passes around the steam blowing pipe 4 in the meantime, it undergoes some preliminary processing. The heated steam flows into the draft tube 2 and descends through the center of the draft tube 2 along the steam blowing pipe 4. At that time, it is heated directly or indirectly by contact with the circulating flow heated by the steam, and eventually mixes with the circulating upward flow in the draft tube 2 and flows out from the upper part into the tank. It will be done.

As explained above, this device has a draft tube suspended in the tank, a steam blowing pipe is inserted and opened at the lower center of the draft tube, and a sludge input pipe is opened at the upper part of the draft tube. A discharge part of the stirring gas supply pipe is installed between the sludge input pipe and the draft tube, so that stirring, heating, and sludge supply can be performed simultaneously within the fairly limited draft tube. As a result, the sludge supplied into the tank is heated at the beginning, so it has good thermal efficiency, and the temperature inside the tank can be made uniform, and the mixing and agitation efficiency of the supplied sludge and the circulating sludge inside the tank can be improved. Improved. In addition, since the steam does not directly heat the sludge contained during digestion, the rate at which microorganisms die due to heat is reduced, and overall digestion efficiency can be greatly improved. can get.

[Brief explanation of the drawing]

The drawing is a longitudinal cross-sectional view showing a main part of an embodiment of this invention. 1...Digestion tank body, 2...Draft tube,
4... Sludge input pipe, 5... Steam blowing pipe, 7... Stirring gas blowing pipe.

Claims (1)

[Scope of utility model registration request] In a draft tube suspended in the tank, a steam blowing pipe is inserted and opened at the lower center of the draft tube, and a sludge input pipe surrounding the steam blowing pipe is opened at the upper part of the draft tube. A digestion tank characterized in that a discharge part of a stirring gas supply pipe is provided between a sludge input pipe and a draft tube.