JPS6233215A - Gas heater - Google Patents

Abstract

PURPOSE:To prevent a temporary increase of a concentration of soot or dust in gas at an outlet of a device by a method wherein the heat exchanger portions at a gas inlet side and a gas outlet side are partitioned by partition plates and damper mechanisms for shielding the gas flow and adjusting an amount of air are arranged. CONSTITUTION:Heat exchanger portions having a plurality of heat-transmitting pipe bundles 9 are installed at each of gas inlet 7 and gas outlet port 8 between each of them, and the inlet side and the outlet side are partitioned by a plurality of partition plates 13. Gas flows passing through each of the partitions are selectively shut off and both of the damper mechanisms 14 and 15 or only either one of them is mounted for adjusting an amount of air flow. A soot-blowing mechanism 16 for removing the adhered soot at the heat exchanger portions when the gas flow is shut off is installed at the downstream side of the heat exchanger portion at the gas outlet part. A suction nozzle 17 for scavenging the re-splashed soot when the soot is blown is arranged at the forward flow side of the heat exchanger portion or the inlet side as well as between the heat exchanger portions, whereby the splashed soot inclusive gas is blown and flowed to a soot-removing facility such as an electric dust collector 19. A temporary increase of a concentration of soot at an outlet part of the device and a deflected flow of gas are prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention This invention relates to gas heaters used in flue gas treatment equipment, particularly in thermal power plants and the like.

BACKGROUND OF THE INVENTION In recent years, thermal power plants have been converting their fuel from heavy oil to cheaper coal, and in order to save energy, wet flue gas desulfurization has been adopted as shown in Figure 3. A heat recovery device 2 receives high-temperature gas 4 at the entrance of the device into the device 1 and performs heat recovery, and a reheater 3 reheats the low-temperature gas 6 that has passed through the device using the recovered heat and sends it to the utilization section 5. As shown in FIGS. 2a and 2b, the gas heater is equipped with a heat exchanger tube bundle 9 for transferring heat between the exhaust gas and the heat medium between the gas input lower and the gas outlet 8, and a gas flow short circuit. It is constructed by disposing a pass prevention plate 10, a soot blowing device 11 for removing soot and dust adhering to heat exchanger tubes, etc., and a water washing device 12 for washing the heat exchanger. However, the conventional gas heater described above has the following drawbacks. In other words, ■ Adhering soot dust is scattered during sootplowing and carried into the gas flow, temporarily increasing the soot dust concentration in the outlet gas of the desulfurization equipment, and ■ When the heat exchanger tube of the gas gas heater is damaged, or the adhering soot dust When the desulfurization equipment becomes unable to function as a heat exchanger due to the increase in the be. Additionally, there is something called a rotary regenerative gas heater that has the same function as the gas heater mentioned above.
Compared to the above-mentioned heater, this gas-gas heater has the drawbacks of soot and dust leakage at 11fflL compared to the above-mentioned heater, and that the soot-and-dust concentration at the device outlet increases due to the peeling of soot and dust attached to the element. is being changed.

As mentioned above, in the current situation where cheap coal is being converted to fuel, flue gas treatment equipment is required to treat flue gas with a high concentration of soot and dust, and also from an environmental standpoint, The treatment of concentrated soot and dust has become an important issue, and in the past, the environmental regulation values were quite lenient compared to when burning heavy oil due to the high cost of countermeasures. Due to technological advances in soot and dust treatment equipment and an increase in the actual operating volume of coal-fired flue gas treatment equipment, the situation is changing to the point where no special treatment is given to coal-fired flue gas, and low soot and dust concentration regulations are required even when burning heavy oil. In addition to the above-mentioned drawbacks of conventional gas heaters, there are some areas where it is not acceptable to temporarily increase the soot and dust concentration at the outlet of the treatment equipment during soot blowing, etc. It is thought that in the future, if equipment is not regulated to the same level as current heavy oil-fired equipment, it will become impossible to establish a factory. Countermeasures are being requested by the public and private sectors, including industries such as thermal power plants.

Problems to be Solved by the Invention The object of the present invention is to prevent a temporary increase in the concentration of soot and dust in the exhaust gas that occurs during soot blowing of a gas heater of a flue gas treatment device in a thermal power plant or the like.

Means for Solving the Problems The present invention divides the heat exchange portions disposed on the gas inlet side and the gas outlet side, respectively, by a plurality of partition plates, and at least divides the heat exchange portions on the inlet side or the outlet side. A damper mechanism is installed on one side that can selectively shut off the gas flow passing through the section and adjust the air flow rate, and furthermore, on the downstream side of the heat exchange section on the gas outlet side, when the damper mechanism shuts off the gas flow, soot and dust adhering to the heat exchange section are installed. In addition to being equipped with a soot blowing mechanism for removing dust, a dust scavenging mechanism is also installed for scavenging re-dispersed dust between the side heat exchange parts and in front of the inlet side heat exchange part.

Therefore, according to the configuration of the present invention, the damper mechanism of the heat exchange section divided into a plurality of sections is completely closed to block the gas flow in at least one section, and the damper mechanism in the remaining subsections is used to completely close the damper mechanism of the heat exchange section divided into a plurality of sections. Adjusting the scenery of the division to prevent uneven heat exchange, and expelling air or steam from the soot blowing mechanism of the cutoff division to peel off and remove the attached soot and dust;
Next, the scattered dust is sucked by the scavenging fan of the dust scavenging mechanism, and the gas containing the dust is sent to dust removal equipment such as an electrostatic precipitator to separate and remove the dust, thereby preventing a temporary increase in the outlet concentration.

Embodiment Next, an embodiment of the present invention will be described with reference to the drawings. In FIG.
A heat exchange section with a heat exchange section is provided, and the person and the exit side are divided into one section by a plurality of partition plates 13, and the gas flow passing through the section during the downstream flow on the exit side of each section is selectively blocked. and a damper mechanism 14 that can freely adjust the air volume, and a similar damper mechanism 15 on the upstream side of the inlet side, or only one of the two damper mechanisms described above, and the damper mechanism 14 on the downstream side of the heat exchange section on the gas outlet side. A soot blowing mechanism 16 is installed to remove the soot and dust adhering to the heat exchange section of the shutoff section when the gas flow is shut off by the mechanism, and furthermore, the soot blowing mechanism 16 removes the soot and dust adhering to the heat exchange section of the shutoff section, and the soot blowing mechanism 16 removes the soot and dust that is redispersed during soot blowing between the side heat exchange sections and on the upstream side of the inlet side heat exchange section. A suction nozzle 17 is disposed to scavenge the air, and a suction fan 18 is interposed in the connection pipe of the nozzle to remove the scattered dust-containing gas from the dust removal equipment 1 such as an electrostatic precipitator.
This device includes a soot and dust scavenging mechanism 20 that sends air to the air.

Effects of the Invention As described above, the present invention can prevent a temporary increase in the dust concentration at the exit of the device, and since the air volume can be freely adjusted using a damper mechanism, it prevents gas drift and uneven heat exchange performance. Furthermore, the present invention has great industrial utility value, such as being able to deal with any abnormalities in the heat exchanger without having to stop the flue gas treatment equipment.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional front view of main parts showing an embodiment of the present invention;
Fig. 2a is a longitudinal sectional front view of the main parts of a conventional gas gas heater;
FIG. 2b is a previous sectional view taken along the line XX, and FIG. 3 is an explanatory diagram of the circuit system of the gas gas heater. 1. Wet flue gas desulfurization equipment, 2. Heat recovery device, 3. Reheater, 4. High temperature gas, 5. Utilization section, 6. Low temperature gas, 7. Gas inlet, 8.. Gas outlet, 90 - heat transfer tube bundle, 10 - gas flow short path prevention plate, 11 - soot blowing device, 12 - water washing device, 13 - partition plate, 14 - O damper mechanism, 15 - damper mechanism, 1
6.9 stroke blowing mechanism, 17.0 suction nozzle,
18. Cloud suction fan, 19. Soot and dust removal equipment, 1 person working at 2°)

Claims (1)

[Claims] The heat exchange portions disposed on the gas inlet and outlet sides are divided into a plurality of sections by a plurality of partition plates, and the gas flow passing through the sections is directed to at least one of the inlet and outlet sides of the sections. A gas heater characterized by installing a damper mechanism that can selectively shut off and adjust the air volume.