JPS5814000Y2 - Digester steam blowing equipment - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an improvement of a device that blows steam into sludge in a digestion tank in order to heat the sludge and improve its digestion.

Conventionally, as a steam blowing device for a digester tank as described above, a steam pipe with a check valve is connected to the boiler, and a steam blowing nozzle connected to this steam pipe is opened into the sludge in the digester tank to remove the sludge generated in the boiler. A method is used in which steam is blown into the sludge from the nozzle through a steam pipe.

In such steam blowing equipment, when the steam injection is stopped and the steam pipes are cooled, the steam in the steam pipes condenses and the pressure inside the steam pipes is reduced. Sludge can be sucked into the steam pipe through the nozzle and corrode the check valve, or if the check valve is defective, the sludge can enter the boiler.

To prevent this, it is possible to blow air into the steam pipe so that the pressure does not decrease, but the blown air mixes with the digestion gas and the digestion gas contains a large amount of methane gas, causing an explosion. There is a risk of it happening.

In addition, since the reliability of the check valve is low, a gate valve is installed in the steam pipe in the boiler, and the gate valve is opened when steam is being blown in and closed when the steam is not being blown. There is a problem that opening and closing operations are troublesome.

This idea solves the above-mentioned problem by forming a constriction part in the steam blowing nozzle and opening the impulse pipe communicating with this constriction part into the gas phase in the upper part of the digester tank. This prevents sludge from flowing back into the steam pipe when the steam blower is stopped, and prevents steam and
・The purpose of this invention is to provide a steam blowing device for a digester that can prevent the steam phenomenon.

An embodiment of this invention will be described below with reference to the drawings.

In Fig. 1, 1 is a boiler, and this boiler 1
A steam pipe 3 having a check valve 2 is connected to the steam pipe 3, and a steam blowing nozzle 4, which will be described later, is connected to the tip of the steam pipe 3.

Further, 5 is a digestion tank, and a sheath pipe 6 is fixed to the upper part of this digestion tank 5 by penetrating it vertically, and penetrating the upper wall 6a of the sheath pipe 6 and inserting it into the sheath pipe 6. The nozzle 4 is inserted concentrically and is fixed to the upper wall 6a of the sheath tube 6.

The nozzle 4 is formed with a constriction part 4a, the lower end of which is opened into the sludge γ in the digestion tank 5.
A small-diameter pressure impulse pipe 8 communicating with a is fixed to the peripheral wall 6b of the sheath pipe 60 and opens into the gas phase part 9 in the digestion tank 5.

In FIG. 1, 10 is a sludge inlet pipe, and 11 is a discharge pipe.

Next, the operation of the steam blowing device configured as above will be explained.

During normal steam injection as shown in FIG. 2, steam from the boiler 1 passes through the check valve 2, the steam pipe 3 and the nozzle 4, and is blown into the sludge 7 from the opening at its lower end.

At the same time, the pressure impulse pipe 8 is communicated with the throttle part 4a of the nozzle 4, so that the digestion gas in the gas phase part 9 in the digestion tank 5 is sucked into the nozzle 4 from the pressure impulse pipe 8 by the ejector action. It is blown into the sludge along with steam.

Therefore, the occurrence of the steam phenomenon caused by the bubbles of the digestion gas is reduced.

In addition, when the steam blower stops due to boiler shutdown, etc.
When the pressure inside the steam pipe 3 and the nozzle 4 is reduced, as shown in FIG.
The sludge is sucked into the side parts and replaced with steam, filling the interior with digestion gas, which causes sludge to be sucked through the nozzle 4 and flow back into the steam pipe 3, corroding the check valve 2 with the sludge, etc. It does not adversely affect its sealing action.

As explained above, according to this invention, it is possible to prevent sludge from flowing back into the steam pipe when steam blowing is stopped without adding a gate valve and performing troublesome operations such as opening and closing it. The effect of preventing the steam phenomenon from occurring when steam is blown is obtained.

[Brief explanation of drawings]

FIG. 1 is a structural explanatory diagram showing one embodiment of this invention, and FIGS. 2 and 3 are enlarged longitudinal sectional views showing the steam blowing nozzle portion during steam blowing and when blowing is stopped, respectively. 1...Boiler, 2...Check valve, 3...Steam pipe,
4... Steam blowing nozzle, 5... Digestion tank, 4a...
Squeezed part, 6... Sheath pipe, 7... Sludge, 8... Impulse pipe, 9... Gas phase part.

Claims (1)

[Scope of utility model registration request] A steam blowing nozzle connected to a steam pipe having a check valve is opened into the sludge in the digestion tank, a constriction is formed in the nozzle, and a pressure pipe communicating with the constriction is connected to the inside of the digestion tank. A steam blowing device for a digester tank characterized by having an opening in the upper gas phase section.