WO2020029046A1

WO2020029046A1 - Shell-type waste heat boiler capable of online ash removal

Info

Publication number: WO2020029046A1
Application number: PCT/CN2018/099059
Authority: WO
Inventors: 刘祥斌
Original assignee: 江苏东九重工股份有限公司
Priority date: 2018-08-06
Filing date: 2018-08-06
Publication date: 2020-02-13

Abstract

A shell-type waste heat boiler capable of online ash removal comprises a shell (6), a steam drum (1), a front smoke box (4), a rear smoke box (7), and a heat exchange tube (5), wherein the steam drum (1) is located above the shell (6), and is supported by a riser tube (3) and a downcomer tube (2). The bottom of a boiler body of the boiler is supported on a cement pier via three supports. The heat exchange tube (5) is a large-diameter heat exchange tube. A first ash bucket (10) is disposed directly below one side of the bottom of the front smoke box (4) close to a front tube panel. A second ash bucket (13) is disposed directly below one side of the bottom of the rear smoke box (7) close to a rear tube panel. A heavy hammer-type automatic ash discharge valve (12) is mounted at each of the bottom of the first ash bucket (10) and the bottom of the second ash bucket (13). At a tail portion of the boiler, multiple ash removal channel devices of which the number and positions are consistent with the number and the positions of holes on the rear tube panel are arranged at the rear smoke box (7). The waste heat boiler allows ash removal to be performed on a boiler heat exchange tube without affecting normal operation of the boiler.

Description

Pot shell type waste heat boiler capable of online ash cleaning

Technical field

The utility model belongs to a heat recovery system equipment, which is suitable for heat recovery of flue gas after incineration of waste gas and waste liquid in the chemical industry, and is particularly suitable for heat recovery of high-temperature flue gas from a cracking furnace in an alkylated waste sulfuric acid treatment device.

Background technique

Existing technology: In the cracking unit of the process flow of the waste sulfuric acid comprehensive recovery device, the high-temperature furnace gas at the outlet of the waste sulfuric acid cracking furnace must be recovered by the waste heat boiler to reduce the furnace gas to a specific temperature before entering the subsequent stage, which can reduce the device. The running cost can ensure the normal operation of the entire device. There are two forms of waste heat boilers in this section, one is a water tube boiler with a membrane wall structure, and the other is a shell boiler. The former water tube boiler with a membrane wall structure has a large steel consumption and investment cost. The shortcomings such as high space and wide area have been completely abandoned by the market. Due to the advantages of simple and compact structure and low investment cost, boiler shell boilers have been widely recognized by the market, but in actual operation, there are the following deficiencies:

1. The boiler shell boiler heat exchange tubes are densely packed in the cylinder. The heat exchange tubes are small diameter seamless tubes. The high temperature furnace gas from the waste sulfuric acid cracking furnace flows continuously inside. The ash accumulation speed in the tube is very fast. The boiler is often shut down for safe operation. After the boiler cools down, it is manually entered into the furnace for dust removal, which causes a large amount of parking loss for users.

2. The high-temperature furnace gas from the waste sulfuric acid cracking furnace contains a small amount of molten cohesive dust and other types of dust. After running for a period of time, it is deposited on the inner wall of the heat exchange tube and blocked, due to the structural characteristics of the shell-type waste heat boiler It cannot be removed by mechanical means, and eventually the heat transfer of the boiler deteriorates and tube explosion accidents often occur.

Summary of the invention

The utility model aims at the above technical problems, and develops a shell-and-shell type waste heat boiler equipment with large diameter heat exchange tubes and capable of manually removing ash accumulated in the heat exchange tubes under the state of non-stop furnace under negative pressure.

In order to achieve the above technical objectives, the present invention adopts the following technical solutions:

A pot shell type waste heat boiler capable of online ash cleaning, comprising: a pot shell, a steam drum, a front smoke box, a rear smoke box and a heat exchange tube, wherein the steam drum is located above the pot shell, and is composed of a rising pipe and a lowering pipe. Tube support; the bottom of the boiler body is supported on the cement pier by three supports; the heat exchange tube is a large-diameter heat exchange tube, and a first drop is set directly below the front smoke box side near the front tube plate side Ash hopper; a second ash drop hopper is set directly below the bottom of the rear smoke box near the side of the rear tube sheet; a heavy hammer-type automatic ash discharge valve is installed at the bottom of the first ash drop hopper and the bottom of the second ash drop hopper ; At the rear of the boiler, a number of ash cleaning channel devices are arranged on the rear smoke box in accordance with the number and position of the openings on the rear tube plate. The three supports include a fixed support provided at the bottom of the boiler body, a first sliding support provided at the bottom of the front smoke box, and a second sliding support provided at the bottom of the rear smoke box. The diameter of the heat exchange tube is 76 mm or more. The surface of the front tube sheet is cast with a high temperature resistant fireproof protective layer. A high temperature resistant protective sleeve is installed outside the boiler flue inlet. A sealing cover is provided on each of the dust cleaning channel devices.

The beneficial effects produced by the utility model are:

1. The ash cleaning channel device is set at the tail of the boiler, and is operated one by one. The boiler can be cleaned without stopping the boiler, which reduces the economic loss caused by the shutdown of the boiler.

2. A heavy hammer-type automatic ash discharge valve is set at the bottom of the front and rear smoke bins, which can automatically fall when ash has accumulated to a certain amount, reducing the danger of manual operation.

3. Solved the problem that the horizontal fire tube type waste heat boiler must be stopped for ash cleaning.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of a horizontal boiler shell type waste heat boiler according to the present invention;

In the figure: 1 is a steam drum; 2 is a descending pipe; 3 is a rising pipe; 4 is a front smoke box; 5 is a large diameter heat exchange tube; 6 is a pan shell; 7 is a rear smoke box; 8 is a ash cleaning channel device; 9 is a first sliding support; 10 is a first ash dropping bucket, 11 is a fixed support; 12 is a hammer-type automatic ash discharge valve; 13 is a second ash dropping bucket; 14 is a second sliding support.

detailed description

In Fig. 1, the flue gas is diverted from the front smoke box 4, and the large-diameter heat exchange pipe 5 is flushed longitudinally, and the confluence is led out from the side to the next process in the rear smoke box 7. The steam drum 1 is located above the pot shell 6 and is supported by the ascending pipe 3 and the descending pipe 2. The boiler water enters the shell-side space of the pot shell 6 through the descending pipe 2 and then enters the steam drum 1 through the riser pipe 3 for steam-water separation after being heated. The entire weight of the boiler is supported by three supports connected to the lower furnace body and the smoke box. On the cement pier, the fixed support 11 is arranged below the furnace body, and the lower parts of the two ends of the cigarette box are respectively connected with the first sliding support 9 and the second sliding support 14 to meet the requirements of the expansion of the furnace body. When the boiler needs dust cleaning under negative pressure, the dust cleaning channel device 8 can be quickly opened one by one, using a stainless steel cleaning rod, the cleaning rod is a long round steel of about Φ20, and the top is equipped with a stainless steel wire brush to penetrate the cleaning channel 8 The steel wire brush directly reaches the inside of the large-diameter heat exchange tube 5 and pushes or withdraws the ash brush into the first ash dropping bucket 10 and the second ash dropping bucket 13 on the front and rear smoke boxes, and then passes the heavy-duty ash discharge valve 12 Free fall, and after the dust cleaning is completed, the sealing cover on the dust cleaning channel device 8 is closed.

Claims

A pot shell type waste heat boiler capable of online ash cleaning, comprising: a pot shell, a steam drum, a front smoke box, a rear smoke box and a heat exchange tube, wherein the steam drum is located above the pot shell, and is composed of a rising pipe and a lowering pipe. Tube support; the bottom of the boiler body is supported on the cement pier by three supports; characterized in that the heat exchange tube is a large diameter heat exchange tube, and the bottom of the front smoke box is directly below the side of the front tube plate A first ash hopper is set; a second ash hopper is set directly below the side of the rear smoke box near the side of the rear tube plate; a heavy hammer type is installed at the bottom of the first ash hopper and the bottom of the second ash hopper Automatic ash unloading valve; at the rear of the boiler, several ash cleaning channel devices are arranged on the rear smoke box with the same number of holes and positions on the rear tube plate.
The shell-and-shell type waste heat boiler capable of on-line ash cleaning according to claim 1, wherein the three supports include a fixed support provided at the bottom of the boiler body, and a first support provided at the bottom of the front smoke box. A sliding support is a second sliding support provided at the bottom of the rear smoke box.
The shell-and-shell type waste heat boiler capable of in-line ash cleaning according to claim 1, wherein the diameter of the heat exchange tube is 76 mm or more.
The boiler shell-type waste heat boiler capable of in-line ash cleaning according to claim 1, wherein a surface of the front tube sheet is cast with a high-temperature and fire-resistant protective layer.
The boiler shell type waste heat boiler capable of on-line ash cleaning according to claim 1, characterized in that a high temperature resistant protective sleeve is installed outside the flue inlet of the boiler.
The boiler shell-type waste heat boiler capable of on-line ash cleaning according to claim 1, wherein a sealing cover is provided on each of the ash cleaning channel devices.