DE102013020815A1 - Continuous process plant for energy-efficient industrial furnaces using a coupled steam power process and residual oxygen optimization - Google Patents

Abstract

Industrial furnaces in a continuous process come z. As in the production of glass, bricks, cement, carbon products or other thermal drying, annealing, sintering, tempering and melting processes for use z. B. according to the 4th BlmSchV Annex, paragraphs 2 and 3. With increased residual oxygen content due to process-related leaks, eg. As at inlet and outlet, and conventional process cooling air to protect conventional fabric filters, the exhaust gas contains considerable uneconomical entrained inert nitrogen loads.
By controlled post-combustion with downstream WRG steam power process with power extraction, use of a regenerative combustion air preheater and condensing gas scrubber, the process plant is now economically optimized and the energy consumption with exhaust gas losses in the sum reduced including environmental or environmental benefits.

Description

to § 10 (2) 1.-3. PatV: Area, S. d. T., problem:

Industrial furnaces (numeral 1 ) come in a continuous flow process z. As in the production of glass, bricks, tiles, utility ceramics, porcelain, cement, quicklime and carbon products or other thermal processes for crystalline dehydrogenation, drying, annealing, sintering, tempering, melting and all loud 4. BlmSchV Annex Numbers 2 and 3 for use. Usually come as fuel urban, natural or liquid gas and fuel oil used. As combustion air supply or oxidizing agent is either conventional air or pure oxygen.

These continuous furnaces have structurally caused leaks against the atmosphere z. B. on construction and masonry joints or at the inlet and outlet for the process material. The exhaust gases are often contaminated with dusts and harmful heavy metals, z. As boron or arsenic. Therefore come cloth filter (numeral 9 ) with shaking mechanism and electrostatic on a case by case basis.

After the S. d. T. is therefore in front of the thermally sensitive textile cloth filters (<200 ° C) atmospheric cooling air (numeral 6 ) mixed. As a result, the potential heat recovery rate decreases uneconomically with the exhaust gas temperature and the entrained inert N 2 nitrogen load increases unfavorably with the O 2 residual oxygen content.

For reasons z. As the strategic secrecy are often no procedurally optimized total solutions used. Also due to operational blindness or inadequate industry overview, the below described after the S. d. T. applicable solutions from other industries often not used. For example, in combined cycle power plants such additional firing after the gas turbine S. d. T. dar.

to § 10 (2) 4.-6. PatV: invention, applicability, advantages:

On the conventional addition of procedural cooling air (paragraph 6 ) with accompanying inert nitrogen load is now omitted. The use of a cycle with economizer preheater (numeral 8th ), Evaporator (numeral 7 ) as well as superheater (numeral 9 ) for cooling the exhaust gas flow allows the abandonment of conventional filter cooling air (Fig 6 ).

For the thermodynamically and economically favorable O2 residual oxygen optimization or reduction on the basis of procedural leaks, the clockwise thermodynamic cycle is preceded by an additional firing in the exhaust gas flow to the superheater. The superheated steam of the respective working medium - water or even an organic chemical - feeds the following working machine (Fig 10 ) for power generation.

The cycle is a damp and corrosion-resistant condensing heat exchanger (numeral 13 ) downstream as a pollutant scrubber and -Abscheider. In the scrubber solution or in the condensate condensate, the pollutant load can be conveniently treated in the liquid state to protect the environment and health.

The completion of the process is a conventional, regenerative rotary heat exchanger (numeral 16 ) as a further preheating stage for the combustion air supply of the industrial furnace (para 1 ) and the additional firing of the cycle (paragraphs 7 . 8th . 9 ). After the S. d. T. is the combustion air supply only in regenerative storage heat exchangers (numeral 2 ) preheated.

The described method reduces the exhaust gas temperature and the harmful O2 residual oxygen content in the exhaust gas, including environmental benefits. A high O2 residual oxygen content is a measure of an unfavorably high load of inert N2 atmospheric nitrogen, which enters the process at ambient temperature and unintentionally leaves the system again when heated to exhaust gas temperature.

Although the use of fuel for additional firing in the subject process plant increases absolutely, but this is converted directly into overheating in the evaporator and thus generated in high efficiency valuable electrical energy and exergy cost and resource-saving.

to § 10 (2) 7. PatV: Exemplary embodiment:

R & I diagram according to p. D. T. describes a common thermal industrial furnace (numeral 1 ) in a continuous flow principle with regenerative combustion air preheating (numbers 2 ).

The industrial furnace is now followed by a water-steam cycle. As a boiler type is occasionally either the flue pipe-large water space construction - with sufficient exhaust gas flow rate - or the water pipe construction z. B. with compressed air or hot steam blower cleaning used.

The process exhaust initially supplies the superheater (Fig 9 ). This is preceded by an additional firing, which controls the O2 residual oxygen controlled in the setpoint mode or completely eliminated. In the process-side emergency operation, regulated combustion air is additionally given up there and the additional firing is increased so that further electricity is generated independently of the process.

To protect the steam power plant against droplet impact or excess temperature, the overheating is regulated or limited by the power of the additional firing. If necessary, a limitation of overheating can be done conventionally by means of surface cooler in bypass circuit.

As a working machine either a steam turbine or a piston steam engine is used.

In the flow direction of the exhaust follow the superheater (numeral 9 ) the evaporator (numeral 7 ) and the economizer feedwater preheater (Fig 8th ).

Finally, there is a condensing heat exchanger (numeral 13 ) as a pollutant scrubber and a controlled regenerative rotary heat exchanger (paragraph 16 ) as a further preheating stage for the combustion air supply.

LIST OF REFERENCE NUMBERS

0

Blower combustion air supply optionally regulated, z. B. by FU

1

Continuous industrial furnace for thermal process

2

Regenerative storage heat exchangers in cyclic loading / unloading operation

3

Exhaust gas suction fan optionally regulated, z. B. by FU

4

possibly exhaust emergency bypass

5

if necessary electrostatic dust filter

6

conventional cooling air blower - Waiver thermodynamically sought

7

Evaporator

8th

Economizer feedwater preheater

9

Superheater regulated with additional firing

10

Steam power plant as a flow or displacement machine

12

Combustion air blower for O2 optimization and reduction, regulated

13

Condensing heat exchanger as pollutant scrubber and separator two-stage

14

Cloth filter with shaking mechanism - renounced

15

Exhaust chimney resistant to moisture and corrosion

16

Regenerative rotary heat exchanger for combustion air preheating

Claims (6)

Process plant for energy-efficient industrial furnaces (para 1 ) in continuous construction for the production of: 1a) glass, 1b) bricks, 1c) tiles, 1d) utility ceramics, 1e) porcelain, 1f) cement, 1g) burnt lime and 1h) carbon products and all related thermal processes: 2a) for crystalline dehydrogenation, 2b) for drying, 2c) for annealing, 2d) for sintering, 2e) for tempering, 2f) for melting and 2g) those according to numbers 2 and 3 Appendix 4. BlmSchV characterized in that it is provided for exhaust gas recirculation with a conventional clockwise thermodynamic cycle including current extraction with the working media: 3a) HOH water (Rankine cycle) or alternatively 3b) organic work equipment (Organic Rankine Cycle) which consists of: 4a) a downstream controlled supplementary firing (see para 9 ) for O2 residual oxygen optimization in the exhaust gas, 4b) a further regulated combustion air blower (paragraph 12 ) for additional or continuous power generation, 4c) a superheater (paragraph 9 ), 4d) of a regulation (para 9 ) of the superheater to protect the working machine, 4e) an evaporator (numeral 7 ) and 4f) a preheater (paragraph 8th ) including a downstream condensing heat exchanger (paragraph 13 ) as an exhaust gas scrubber for pollutant treatment in the liquid phase and a regulated regenerative combustion air preheating (Fig 16 ).

Images