JPH04130187A - Equipment for heating and evaporating slurry - Google Patents

Abstract

PURPOSE:To prevent the deposition of dried slurry on the wall of a heat transfer tube to thereby make it possible to heat and evaporate slurry efficiently by a constitution wherein carrier gas flows into the heat transfer tube through a space between the outside of a supply tube and the inside of a heat transfer tube. CONSTITUTION:In equipment for heating and evaporating slurry, the slurry is fed through an introduction port 15 into a slurry introduction chamber 3, passes through a slurry supply tube 26, and flows into a heat transfer tube 20. On the other hand, carrier gas is introduced from an introduction port 11 into a carrier gas introduction chamber 2 and flows into the heat transfer tube 20. Because of a constitution wherein the carrier gas flows into the tube 20 through a space between the inside of the tube 20 and the outside of the tube 26, a carrier gas layer is formed along the inside of the tube 20 so that the slurry will be heated and evaporated without direct contact with the inside thereof by the heat of high temperature fluid transferred through the wall of the tube 20. The generated steam and granules go into a steam withdrawal chamber 4 and are then withdrawn from a withdrawal port 18. Because the slurry does not come into direct contact with the inside of the tube 20, the dried slurry will not deposit thereon, so that efficient heating and evaporation can be accomplished.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a slurry heating and evaporating device for heating slurry to evaporate a liquid component. More specifically, the present invention relates to a slurry heating evaporation device suitable for incorporating into a partial oxidation process in which a coal-water slurry is supplied to a combustion furnace and partially oxidized to generate gas such as CO1H2.

[Prior Art] A conventional method for partial oxidation of carbonaceous fuel involves burning solid carbonaceous fuel such as coal with oxygen in the presence of water vapor in a combustion furnace to generate gas containing Co, CO2, H2, etc. better known.

Co and C generated by this method of partial oxidation of carbonaceous fuel
Gas containing O2, H2, etc. is used as synthesis gas, reducing gas, fuel gas, etc.

Conventionally, as a method of supplying solid carbonaceous fuel such as coal to a combustion furnace, solid carbonaceous fuel is mixed with water slurry (e.g. coal/
There is a method of making water slurry (CWM) and supplying this slurry as it is to the combustion furnace. This wet feeding method allows carbonaceous fuel to be supplied to the combustion furnace using a pump, which simplifies equipment and facilitates fuel supply.

In the conventional partial oxidation method using a slurry of solid carbonaceous fuel, the thermal energy for evaporating water in the slurry is generated by oxidizing the carbonaceous fuel. Therefore, it is necessary to oxidize a portion of the carbonaceous fuel to CO2 to generate a large amount of thermal energy (heat of combustion). As a result, in the conventional partial oxidation method of solid carbonaceous fuel, Co
There was a problem that the amount of Co produced was large and the yield of Co was small.

Therefore, in a carbonaceous fuel partial oxidation method in which a solid carbonaceous fuel such as coal is partially oxidized in a combustion furnace to generate a gas containing at least Co, CO2, and H2, a carbonaceous fuel slurry is heated. It is conceivable to prepare a mixture of carbonaceous fuel powder and steam, and to supply this solid-gas mixture to the combustion furnace.

Conventionally, as a slurry heating device, a device in which a group of heat transfer tubes is disposed in a passage chamber for high temperature fluid has been used.

[Problems to be Solved by the Invention] When slurry is poured into a heat transfer tube and heated and evaporated, dry matter adheres to the inner surface of the heat transfer tube, extremely reducing the heat transfer coefficient and causing blockage inside the tube. easy.

[Means for Solving the Problems] The slurry heating evaporation apparatus of the present invention includes a high-temperature fluid chamber through which a high-temperature fluid flows, a carrier gas introduction chamber provided at one end of the high-temperature fluid chamber, and a high-temperature fluid chamber through which a high-temperature fluid flows. A steam extraction chamber provided at the other end of the chamber, a heat exchanger tube passing through the high temperature fluid chamber and communicating the carrier gas introduction chamber and the steam extraction chamber, and a high temperature fluid chamber provided on both sides of the carrier gas introduction chamber. A slurry introduction chamber provided on the opposite side of the fluid chamber and the carrier gas introduction chamber are penetrated, one end side is communicated with the slurry introduction chamber, the other end side is inserted into the inside of the heat exchanger tube, and the outer circumferential surface thereof and a slurry supply pipe in which a gap for carrier gas flow is formed between the heat exchanger tube and the inner circumferential surface of the heat transfer tube.

As the carrier gas in the slurry heating evaporation apparatus of the present invention, in addition to water vapor, nitrogen gas, hydrogen gas, carbon dioxide gas, -carbon oxide gas, etc. can be used.

[Function] In the slurry heating evaporation apparatus of the present invention, the slurry is introduced into the heat transfer tube from the slurry introduction chamber through the slurry supply pipe. A carrier gas is also introduced into the heat exchanger tube from a carrier gas introduction chamber. The slurry is evaporated in the heat transfer tube by the heat of the high-temperature fluid transmitted through the heat transfer tube wall, and becomes a mixture of steam and powder.

By the way, the carrier gas introduced into the heat exchanger tube flows into the heat exchanger tube between the outer peripheral surface of the carrier gas supply tube and the inner peripheral surface of the heat exchanger tube, and the carrier gas flows along the inner peripheral surface of the heat exchanger tube. form a layer. Therefore, the slurry flowing out from the tip of the slurry supply pipe is prevented from coming into direct contact with the inner wall surface of the heat exchanger tube, and dry matter is prevented from adhering to the inner wall surface of the heat exchanger tube.

[Example] Examples will be described below with reference to the drawings.

FIG. 1 is a longitudinal sectional view of a slurry heating evaporation apparatus according to an embodiment of the present invention.

This heating evaporation device includes a high temperature fluid chamber 1, a carrier gas introduction chamber 2, a slurry introduction chamber 3, and a vapor extraction chamber 4. The high temperature fluid chamber 1 is surrounded by a cylindrical body 5 on its side peripheral surface, and flanges 6.7 are provided above and below the cylindrical body 5. A head portion 8 is provided at the upper portion of the cylindrical body 5 so as to bulge outward, and a high temperature fluid (for example, combustion gas) is introduced into the head portion 8 portion. A high temperature fluid outlet 9 is provided at the bottom of the high temperature fluid chamber 1 .

The carrier gas introduction chamber 2 has a cylindrical body 10 with a short side circumferential surface.
The cylindrical body 10 is provided with an inlet 11 for carrier gas. Flanges 12 and 13 are provided at both upper and lower ends of the cylindrical body 10, respectively, and the flanges 13 are connected to the flange 6 by bolts.

The slurry introduction chamber 3 is surrounded by an end plate 14, and the end plate 14 is provided with a slurry introduction port 15. End plate 1
4 is provided with a flange 16, and the flange 16
is connected to the flange 12 by bolts.

The steam extraction chamber 4 is surrounded by an end plate 17, and the end plate 17 is provided with a steam extraction port 18.

A heat exchanger tube 20 is disposed passing through the high temperature fluid chamber 1 so as to communicate the carrier gas introduction chamber 2 and the steam extraction chamber 4. Although only one heat exchanger tube 2o is shown in FIG. 1, a large number of heat exchanger tubes 20 are actually arranged in the high temperature fluid chamber 1.

In order to communicate the inside of the heat exchanger tube 20 with the carrier gas introduction chamber 2 and the steam extraction chamber 4, the ends of the heat exchanger tube 20 are provided with openings 21.
22.23 is inserted.

An opening 23 is formed in the upper flange 12 of the carrier gas introduction chamber 2, and a slurry supply pipe 24 is fixed to the opening 23 so that the inside thereof communicates with the slurry introduction chamber 3. . The lower end side of this slurry supply pipe 24 penetrates into the upper part of the heat exchanger tube 2o. Note that a required gap is formed between the outer circumferential surface of the slurry supply pipe 24 and the inner circumferential surface of the heat exchanger tube 20, and the carrier gas in the carrier waste introduction chamber 2 passes through the gap and flows into the heat exchanger tube 2o. The heat exchanger tube 20 is configured to flow into the heat transfer tube 20 along the inner surface thereof.

In the slurry heating evaporation device configured in this way,
The slurry is introduced into the slurry introduction chamber 3 from the introduction port 15,
The slurry is poured into the heat transfer tube 20 through the slurry supply tube 24 . On the other hand, the carrier gas is introduced into the carrier gas introduction chamber 2 from the introduction port 11, and then flows into the heat exchanger tube 20.

At this time, this carrier gas passes through the gap between the inner circumferential surface of the heat exchanger tube 20 and the outer circumferential surface of the slurry supply tube 24 to the heat exchanger tube 2o.
Therefore, a layer of carrier gas is formed along the inner circumferential surface of the heat exchanger tube 20 in the lower region of the slurry supply tube 24 . Therefore, direct contact of the slurry flowing out from the lower end of the slurry supply pipe 24 with the inner peripheral surface of the heat transfer tube 20 is avoided. While flowing down inside the heat exchanger tube 20, the slurry is heated by the heat of the high temperature fluid transmitted through the tube wall of the heat exchanger tube 20, and is evaporated.

The generated steam and powder enter the steam extraction chamber 4,
Then, it is taken out from the take-out port 18.

As described above, according to this slurry heating evaporation device, the slurry does not come into direct contact with the inner surface of the heat transfer tube 20 at all or hardly, and dry matter of the slurry is prevented from adhering to the inner surface of the heat transfer tube 20. . Therefore, the heat transfer coefficient of the heat transfer tube 20 is large, and efficient heating and evaporation can be performed. In addition, clogging of the heat exchanger tubes 20 is reliably prevented, and stable operation can be performed over a long period of time.

In addition, in the present invention, the dimensions Ll and L shown in FIG.
2. It is preferable that I and 3 have the following relationships.

L2 is about 0.7 to 0.9 times that of LI.

L3 is about 0.1 to 0.3 times larger than L2.

FIG. 2 shows a system diagram of a coal partial oxidation device incorporating this heating evaporation device.

In FIG. 2, carbonaceous fuel (coal in this example) and water are supplied to a mill 31 to form a slurry (CWM). This C
After the WM passes through a slurry tank 32 and a slurry pump 33 and is heated in a preheater 34, moisture is evaporated in an evaporator 35 (configured as shown in FIG. 1). The steam and coal powder are sent to a burner 37 of a combustion furnace 36. Burner 3
7 is also supplied with oxygen.

A combustion chamber 39 is formed in the upper part of the combustion furnace 36 and lined with a refractory material 38 . The lower part of the combustion furnace 36 is a gas cleaning chamber 40 , and the combustion chamber 39 communicates with the gas cleaning chamber 40 via a throat portion 41 . Water is filled in the gas cleaning chamber 40 to a halfway height, and a cylindrical dip tube 42 and a draft tube 43 are coaxially provided so that their lower ends are submerged in the water.

Although not shown, a quench ring is provided for supplying water to the upper inner peripheral surface of the dip tube 42 and forming a water belly on the inner peripheral surface.

The gas taken out from the gas outlet 44 provided in the combustion furnace 36 is sent to a venturi scrubber 45 and a gas scrubber 46.
It becomes a deseated product gas. Water is supplied to the gas scrubber 46 from a settler 48, which will be described later. New water is added to the return water from the settler 48 as needed. Water extracted from the bottom of the gas scrubber 46 is returned to the gas cleaning chamber 40 and the Venturi scrubber 45. Slag is extracted from the bottom of the gas cleaning chamber 40 via a lock hopper 47. In addition, particle-containing water is extracted into a settler 48, separated by sedimentation, and discharged outside the system.

In the carbonaceous fuel partial oxidation device configured in this way, carbonaceous fuel, steam, and oxygen are supplied into the combustion furnace 36 via the burner 37, and the carbonaceous fuel is partially oxidized in the combustion chamber 39. . This partial oxidation reaction mainly consists of C○, N2, and Co2, with a small amount (7)
A gas containing N2S, N2, and CH4, as well as unburned carbon and a trace amount of ash, is generated. This gas passes between the dip tube 42 and the draft tube 43 in the gas cleaning chamber 40, undergoes carbon and ash removal treatment, is further subjected to dust removal treatment in a venturi scrubber 45, and then passes through a gun scrubber 46. Any remaining traces of carbon are also removed.

Therefore, since the water supplied to the combustion furnace 36 is in the form of steam, the combustion heat of the carbonaceous fuel generated within the combustion furnace 36 is not consumed for vaporizing water. As a result, the amount of CO2 generated decreases and the CO yield increases.

[Effects of the Invention] As described above, according to the slurry heating evaporation apparatus of the present invention,
Since a layer of carrier gas is formed along the inner surface of the heat exchanger tube, adhesion of dried slurry to the inner surface of the heat exchanger tube is prevented. Therefore, the slurry can be efficiently heated and evaporated, and the heat transfer tubes are not clogged, so that the operating condition becomes stable over a long period of time.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an example apparatus, and FIG. 2 is a diagram of a coal gasification process. 1... High temperature fluid chamber, 3... Slurry introduction chamber, 20... Heat exchanger tube. 2... Carrier gas introduction chamber, 4... Steam extraction chamber,

Claims (1)

[Claims] A high-temperature fluid chamber through which high-temperature fluid flows; a carrier gas introduction chamber provided at one end of the high-temperature fluid chamber; and a steam extraction chamber provided at the other end of the high-temperature fluid chamber. , a heat transfer tube passing through the high temperature fluid chamber and communicating the carrier gas introduction chamber and the steam extraction chamber; and a slurry introduction chamber provided on the opposite side of the high temperature fluid chamber with the carrier gas introduction chamber in between. , passes through the carrier gas introduction chamber, one end side is communicated with the slurry introduction chamber, the other end side is inserted into the inside of the heat exchanger tube, and the carrier gas is passed between the outer circumferential surface and the inner circumferential surface of the heat exchanger tube. A slurry heating evaporation device comprising: a slurry supply pipe in which a gap for circulation is formed;