CN217209446U

CN217209446U - Tail gas treatment system of natural gas heat conduction oil boiler co-combustion equipment

Info

Publication number: CN217209446U
Application number: CN202220322622.6U
Authority: CN
Inventors: 杨星星; 庄宁; 宋爱华
Original assignee: Hubei Yihua Degradation New Material Co ltd
Current assignee: Hubei Yihua Degradation New Material Co ltd
Priority date: 2022-02-17
Filing date: 2022-02-17
Publication date: 2022-08-16
Anticipated expiration: 2032-02-17

Abstract

A tail gas treatment system of mixed combustion equipment of a natural gas heat conduction oil boiler comprises a natural gas heat conduction oil boiler combustion system, wherein the natural gas heat conduction oil boiler combustion system comprises a heat conduction oil boiler, a combustor, a waste heat boiler, an air preheater, a chimney and a natural gas inlet line; a first tail gas conveying pipe is additionally arranged at a fuel port of the combustor and used for conveying first tail gas, and the first tail gas is used for providing second fuel for the combustor. The utility model makes full use of the fuel value of the tail gas and reduces the fuel consumption; the emission reaching the standard is realized.

Description

Tail gas treatment system of natural gas heat conduction oil boiler co-combustion equipment

Technical Field

The utility model belongs to the technical field of polybutylene terephthalate-adipate (PBAT) production, in particular to natural gas heat conduction oil boiler mixes equipment tail gas processing system that burns.

Background

Two tail gases, namely, a stripper tail gas (hereinafter referred to as a first tail gas) and a stripper tail gas (hereinafter referred to as a second tail gas), are mainly generated in a polybutylene terephthalate-adipate (PBAT) production device. The traditional tail gas treatment process comprises 2 types, one type is that the tail gas is discharged to the sky after being filtered by a filter, the mode is obvious inorganization discharge and can not reach the discharge standard, and in addition, the tail gas of the device of the process contains THF (tetrahydrofuran), so that the discharge port has large peculiar smell; the second mode is that the tail gas is directly extended into the furnace at the bottom of the heat-conducting oil boiler through a pipeline for combustion treatment in a simple pipe connecting mode. The mode is adopted in the past polyester industry and PBAT devices in large quantity, but with the release and execution of new boiler safety technical code TSG 11-2020 (new boiler standard for short), the mode that the process tail gas of the device enters the hearth through the connecting pipe to be combusted does not meet the specification of the new boiler standard in 2020. In order to meet the standard of the treatment of the process tail gas of the PBAT device in legal compliance, besides the two unlawful modes, a mode of directly introducing the process tail gas into a tail gas incinerator for combustion by taking natural gas as fuel gas through newly building a set of RTO device to meet the standard of emission appears in the industry, and although the mode achieves the purpose of meeting the standard of emission, the investment is relatively large.

There is currently no efficient means to treat both off-gases.

Disclosure of Invention

In view of the technical problems existing in the background art, the tail gas treatment system of the mixed combustion equipment of the natural gas heat conduction oil boiler provided by the utility model fully utilizes the fuel value of the tail gas and reduces the fuel consumption; the emission reaching the standard is realized.

In order to solve the technical problem, the utility model discloses following technical scheme has been taken and has been realized:

a tail gas treatment system of mixed combustion equipment of a natural gas heat conduction oil boiler comprises a natural gas heat conduction oil boiler combustion system, wherein the natural gas heat conduction oil boiler combustion system comprises a heat conduction oil boiler, a combustor, a waste heat boiler, an air preheater, a chimney and a natural gas inlet line; a first tail gas conveying pipe is additionally arranged at a fuel port of the combustor and used for conveying first tail gas, and the first tail gas is used for providing second fuel for the combustor.

In the preferred scheme, a combustion tail gas discharge port of the heat conduction oil boiler is sequentially connected with the waste heat boiler, the air preheater and the chimney through pipelines.

In a preferred scheme, the first blower provides combustion air for the combustor through the air preheater.

In a preferred scheme, the combustion system of the natural gas heat transfer oil boiler further comprises a second air blower, and the second air blower is used for circularly introducing tail gas discharged by the air preheater into the combustor.

This patent can reach following beneficial effect:

mixing the second tail gas (containing THF with extremely low concentration and PPM level) from the leaching tower with air (far below the explosion limit) through a first blower inlet to form combustion-supporting air, and feeding the combustion-supporting air into a hearth for combustion; the first tail gas (containing THF with higher concentration) from the stripping tower is fed into a hearth together with natural gas through a burner internal channel of the boiler for combustion. The mode that tail gas got into the boiler accords with the requirement of new pot rule, and the effect that reaches is: the fuel value of the tail gas is fully utilized, and the fuel consumption is reduced; the emission reaching the standard is realized.

Drawings

The invention will be further explained with reference to the following figures and examples:

FIG. 1 is a system structure diagram of the present invention;

fig. 2 is a structural diagram of a combustion system of a natural gas conduction oil boiler.

In the figure: the device comprises a heat conduction oil boiler 1, a combustor 2, a waste heat boiler 3, an air preheater 4, a chimney 5, a natural gas inlet line 6, a first air blower 71, a second air blower 72 and a regulating valve 8.

Detailed Description

The preferred scheme is as shown in figures 1 to 2, a tail gas treatment system of a mixed burning device of a natural gas heat-conducting oil boiler comprises a combustion system of the natural gas heat-conducting oil boiler, as shown in fig. 2, the existing combustion system of a natural gas heat conduction oil boiler comprises a heat conduction oil boiler 1, a burner 2, a waste heat boiler 3, an air preheater 4, a chimney 5 and a natural gas inlet line 6, wherein a first blower 71 is arranged at an inlet of the air preheater 4, the natural gas inlet line 6 is used for providing a first fuel for the burner 2, the first blower 71 is used for providing combustion-supporting air for combustion of natural gas, the air is heated by the air preheater 4 and then introduced into the burner 2, the natural gas is combusted to provide a heat source for the heat conduction oil boiler 1, tail gas combusted in the heat conduction oil boiler 1 is introduced into the waste heat boiler 3, and the waste heat boiler 3 is used for utilizing waste heat of the tail gas to work and is beneficial to heat recovery; and the tail gas is discharged to a chimney 5 through an air preheater 4 after passing through a waste heat boiler 3. A plurality of pipelines are arranged in the air preheater 4, and tail gas can be directly discharged to a chimney 5 after passing through the waste heat boiler 3.

The combustion system of the natural gas conduction oil boiler further comprises a second air blower 72, and the second air blower 72 is used for circularly introducing tail gas discharged by the air preheater 4 or tail gas at the inlet of the chimney 5 into the combustor 2. And the gas which is not fully combusted is prevented from being discharged into the atmosphere, and the combustion efficiency is improved.

On the basis of the prior art, the technical scheme is specifically improved as follows:

a second tail gas conveying pipeline is additionally arranged at the air inlet of the first air blower 71 and is used for conveying second tail gas; a first tail gas conveying pipe is additionally arranged at a fuel port of the combustor 2 and used for conveying first tail gas, and the first tail gas is used for providing second fuel for the combustor 2.

The first tail gas is used as fuel and is led into the combustor 2 for combustion. The combustor 2 is an ultra-low emission NOX combustor, the combustor is provided with two air inlets, one is a natural gas inlet, the other is a first tail gas inlet, a nozzle of natural gas is arranged in the center of the combustor, and the first tail gas nozzle is uniformly distributed on the periphery of the combustor; the natural gas inlet and the first tail gas inlet are respectively provided with independent PID regulation;

preferably, the second tail gas and air are mixed by a mixer and then are introduced into the air preheater. In order to avoid the leakage of the first tail gas and the second tail gas caused by the sudden stop of the blower, the first tail gas and the second tail gas are respectively arranged on the bypass of the first tail gas and the bypass of the second tail gas in a pipe way to the activated carbon filter. And in the stage of shutdown or open circuit of the heat transfer oil boiler 1, the first tail gas and the second tail gas are all filtered by the filter and then discharged.

The operation method comprises the following steps:

in the starting-up stage of the heat-conducting oil boiler 1, first tail gas and second tail gas are filtered and discharged through a filter; after the heat conducting oil boiler 1 normally operates, the regulating valve of the first tail gas inlet burner is gradually opened, the second tail gas enters the regulating valve of the first air blower inlet, and the valve of the inlet filter is synchronously closed. According to the parameters set by the program, the PLC automatically adjusts the air input of each path of tail gas, thereby achieving completely stable blending combustion; in the process of blowing out, the regulating valve for feeding tail gas is preferably closed, so that the tail gas is discharged through the filter, and the natural gas and blast volume are synchronously reduced, thereby achieving safe blowing out.

The above-mentioned embodiments are merely preferred embodiments of the present invention, and should not be considered as limitations of the present invention, and the protection scope of the present invention should be defined by the technical solutions described in the claims, and includes equivalent alternatives of technical features in the technical solutions described in the claims. Namely, equivalent alterations and modifications within the scope of the invention are also within the scope of the invention.

Claims

1. The utility model provides a natural gas heat conduction oil boiler mixes equipment tail gas processing system that burns, includes natural gas conduction oil boiler combustion system, natural gas conduction oil boiler combustion system include conduction oil boiler (1), combustor (2), exhaust-heat boiler (3), air heater (4), chimney (5) and natural gas inlet line (6), the entry of air heater (4) is equipped with first air-blower (71), natural gas inlet line (6) are used for providing first fuel, its characterized in that for combustor (2): a second tail gas conveying pipeline is additionally arranged at the air inlet of the first air blower (71), and the second tail gas conveying pipeline is used for conveying second tail gas; a first tail gas conveying pipe is additionally arranged at a fuel port of the combustor (2), the first tail gas conveying pipe is used for conveying first tail gas, and the first tail gas is used for providing second fuel for the combustor (2).

2. The tail gas treatment system of the natural gas heat transfer oil boiler co-combustion equipment according to claim 1, characterized in that: the combustion tail gas discharge port of the heat conduction oil boiler (1) is sequentially connected with the waste heat boiler (3), the air preheater (4) and the chimney (5) through pipelines.

3. The tail gas treatment system of the natural gas heat transfer oil boiler co-combustion equipment according to claim 2, characterized in that: the first blower (71) supplies combustion air to the combustor (2) through the air preheater (4).

4. The tail gas treatment system of the natural gas heat transfer oil boiler co-combustion equipment according to claim 3, characterized in that: the combustion system of the natural gas heat transfer oil boiler further comprises a second air blower (72), and the second air blower (72) is used for circularly introducing tail gas discharged by the air preheater (4) into the combustor (2).