Gasification of ring furnace by brick firing

1. general part.

The working design of gasification is performed on the basis of the customer approved design task, technical specifications for gas supply and in accordance with the following regulatory documents:

- SniP 42012002 "Gas distribution systems";

- SP 421022004 "Design and construction of gas pipelines from metal pipes";

- SP 421012003 "General provisions for the design and construction of gas distribution systems made of metal and polyethylene pipes";

- PB36800 "Safety rules in gas industry";

- GOST 21.61085 SPDS "Gas supply." External networks. Working drawings.

2. information on justification of the selected construction site.

Construction site located in IIIB

climatic area and characterized by the following conditions:

Design winter temperature

16 ° С outdoor air

predominant direction

wind VZ

wind speed head 0.6 kpa

weight of snow cover 0.5 kpa

normative depth of seasonal

ground freezing 0.6 m

seismicity of section 9 points

The relief of section P of the difficulty group with a fall in the east direction.

4. technological solutions.

This project provides for the construction of a medium pressure gas supply pipeline and gasification of a circular furnace for burning bricks. The tie-in point is the existing high-pressure gas pipeline passing through the territory of Pioneer LLC. Pressure is reduced to medium pressure by pressure regulator RDBK50N (B), according to the passport data of which it provides the required gas volume capacity. Gas metering is performed by gas meter TGS400. The external gas pipeline through the territory of the workshop should be carried out above ground on metal supports and on the wall of industrial buildings. At the site of gas pipeline tie-in to the existing and at the inlet of the gas pipeline to the workshop building, install disconnecting valves. Gate valves with diameter up to 80mm are accepted as per cl. In (class of shut-off valves for tightness), with a diameter of more than 80mm according to With

The above-ground gas pipeline should be covered with 2 layers of primer and 2 layers of enamel intended for external work.

Operation of the annular furnace is provided on medium pressure gas 0,020,50Mpa. The operation of the furnace is provided for 2 lights with a gas flow rate of 350 m3/h.

Brick firing is provided by bottom burners at the bottom of the chamber. One burner with 12 nozzles is installed in each chamber. For a more uniform distribution of temperatures, portable burners are provided in the furnace duct, which can be introduced into the furnace through the embrasure in the chamber roof. The upper burner is connected to the gas pipeline by means of a rubber-woven hose D20mm, P = 0.16MPa. The main gas pipeline is laid along the edge of the furnace on supports at a height of 0.9 m.

The workshop room shall be equipped with an air control system for carbon monoxide and methane content.

Gas pipelines shall be tested for air tightness. Testing of gas pipelines is carried out by supplying compressed air to the gas pipeline and creating test pressure in the gas pipeline. Value of test pressure and time of holding under pressure of steel above-ground gas pipelines are given in Table 17 of SNiP 42012002 "Gas distribution systems." Test pressure for medium pressure gas pipelines - 1.25 from the working one, but not more than 0.3MPa, holding time - 1h. To test the gas pipeline, it should be divided into separate sections limited by plugs. The results of the leak test shall be considered positive if the pressure drop by the pressure gauge of accuracy class 0.15 is not visible during the period of the gas pipeline test, but by the pressure gauges of accuracy class 0.15 and 0.4, as well as by the liquid pressure gauge, the pressure drop is recorded within one division of the scale.

When completing the gas pipeline test, the pressure should be reduced to atmospheric pressure, the valves should be installed and the gas pipeline should be held for 10 minutes under working pressure. Check tightness of detachable joints with soap emulsion.

Outside air temperature during testing shall not be lower than minus 15 degrees. Defects detected during the gas pipeline test should be eliminated only after the pressure in the gas pipeline is reduced to atmospheric. Once the defects have been eliminated, the test shall be repeated. Gas pipeline joints welded after testing shall be checked by physical inspection.

The pipe material for gas transportation is accepted according to Table 1 of SP 421022004 "Design and construction of gas pipelines of their metal pipes," according to GOST 1070479, steel grade St3sp according to GOST 105088 .

Electric arc manual welding is used to connect pipes. Types, structural elements and dimensions of welded joints of steel gas pipelines shall comply with GOST 16037. The technology of welding gas pipelines includes: preparation of pipes for welding, assembly of joints, basic welding of pipes in a section and welding of pipes or sections into a thread. Preparation of edges for standard preparation is performed by machining with subsequent grinding of slip-machine. Before assembling pipes, you must:

- clean the internal cavity of pipes and parts from soil, dirt, snow and other contaminants;

- clean the edges and adjacent internal and external surfaces of pipes, parts of gas pipelines, branch pipes, fittings for width not less than 10 mm to metal gloss;

- check the geometric dimensions of the edges, straighten the smooth dents at the ends of the pipes up to 3.5% of the outer diameter of the pipe;

- clean the edges and adjacent inner and outer surfaces of pipes to a width of not less than 10 mm.

Pipe ends with cracks, breaks, nicks, chamfer balls

more than 5 mm deep, trimmed.

If the air temperature is below minus 5 ° С, straightening the pipe ends without heating them is not recommended. Pipe joints are assembled on inventory beds using external or internal centralizers. Manual arc welding of non-rotating and rotary joints of pipes at wall thickness up to 6 mm is performed in at least two layers. Each seam layer is thoroughly cleaned of slag and metal splash before application of the subsequent seam.

la. For arc welding of pipes the following types of electrodes according to GOST 9467, GOST 9466 are used:

- E42C, E46-C with diameter 2.0; 3,0; 3,25; 4.0 mm with cellulose coating - for welding of root layer of IIII pipe seam.

Standards for control of butt joints for steel gas pipelines are adopted as per Table 14 of SNiP 421012002 "Gas distribution systems." Joints of steel gas pipelines shall be monitored by radiographic method according to GOST 7512 and ultrasonic method according to GOST 14782. If unsatisfactory radiographic results are obtained at at least one joint, the inspection volume should be increased to 50% of the total number of joints.

In case of repeated detection of defective joints, all joints welded by the welder at the facility during the calendar month and checked by ultrasonic method shall be subjected to radiographic inspection. Rectify defects according to the requirements of section 10.4. "Physical Control" SniP 421012002 "Gas Distribution Systems."

When performing all installation works, it is necessary to follow the requirements of SNiP III480 "Safety in construction."

5.automatics of safety and instrumentation.

The functional diagram developed in the project provides for:

- thermal control of the main process parameters;

- stop of gas supply to burners at actuation of one of safety automation sensors;

- alarm with detection of the root cause of the accident.

Thermal control.

The following instruments are controlled by the design provided by the scheme:

- gas pressure upstream of CEPG100P valve;

- gas pressure downstream of CEPG100P valve;

- the gas pressure in the header upstream of the burners of the respective furnace firing chamber;

- vacuum upstream of the smoke pump;

- burning temperature in the furnace chamber;

- flue gas temperature of the smoke pump.

Security automation.

Design safety automation to stop gas supply to burners in the following cases:

- gas pressure drop;

- increase of gas pressure;

- flue gas discharge drop before the smoke pump;

- power outage.

6. Environmental protection.

The use of natural gas makes it possible to significantly improve sanitary conditions, clean the air basin from ash, soot and reduce oxides of nitrogen, carbon dioxide, sulfurous anhydride in the surface layers of the atmosphere. The improvement of the atmosphere in the area adjacent to consumers of natural gas is achieved due to the fact that when burning natural gas in combustion products there are no above mentioned harmful impurities compared to coal operation.