CN103822803A

CN103822803A - Sand casting tail gas acquisition device and method

Info

Publication number: CN103822803A
Application number: CN201410070425.XA
Authority: CN
Inventors: 龙威; 黄晋; 夏露; 张友寿; 杨剑雄; 王小路
Original assignee: Hubei University of Technology
Current assignee: Hubei University of Technology
Priority date: 2014-02-28
Filing date: 2014-02-28
Publication date: 2014-05-28

Abstract

The invention provides sand casting tail gas acquisition equipment and its method which are used for pollution-free acquisition of casting tail gas. The acquisition equipment is composed of a pouring furnace, a pouring platform, a sandbox and a sealed cowling which are arranged on the pouring platform and a riser tube for communicating the pouring furnace and the sandbox. The sealed cowling is connected with a gas pressure transducer and has a vacuum-pumping channel and a gas acquisition channel. A furnace lid of the pouring furnace has an inert gas channel. After gas pressure in the sealed cowling reaches a preset value of the gas pressure transducer, the transducer gives an alarm, and an electric suction pump is started up to pump the gas in the sealed cowling to a gas sampling bag for later detection. The device and method provided by the invention are used for pollution-free acquisition of casting tail gas. The acquisition device is small in size, has a simple structure and is convenient to operate.

Description

A kind of harvester of sand casting tail gas and method

Technical field

The harvester and the method that the present invention relates to a kind of sand casting tail gas, belong to field of metal casting technology.

Background technology

China is maximum in the world castings production state, and within 2013, casting output has exceeded 4,000 ten thousand t, accounts for 40% of global casting output.In multiple forging type, sand casting, because production cost is low, technique is simple, is used in the world in a large number, and the foundry goods that uses sand casting to produce accounts for 70%～80% of production.But the air pollution problems inherent of sand casting is very serious, according to statistics, the waste gas of China's foundry industry discharge in 2006 is about 300～60,000,000,000 m ³, wherein the overwhelming majority is the discharge of sand casting enterprise.Research is in recent years found, in the waste gas of sand casting factory discharge, removes and contains CO, the CO that people know ₂also contain in a large number environment and harmful volatile organic matter (Volatile Organic Compound, VOC) and the Hazardous Air Pollutant (Hazardous Air Pollutant, HAP) of human body outward.In the 188 kinds of HAP altogether that list in EPA, in sand casting factory waste gas, detect more than 40 and planted, as formaldehyde, benzene and phenol etc.

VOC is the precursor of atmospheric photochemical reaction, and immunity, nerve and digestive system to human body all can cause damage, and HAP has pungency, toxicity and carcinogenicity, can produce acute hazard to human body.Correlative study discovery, VOC and HAP that sand casting produces can cause long-term damage to operator's respiratory system, bring out the generation of respiratory system chronic disease and lung cancer.The units such as EPA, american foundrymen's societry, U.S. Department of Defense and US Council for Automotive Research department of Commerce combined in 1994 and have carried out casting air pollutants reduction of discharging plan, organized VOC and the HA P control technology of particular study mechanism to sand casting to study.

Compared with other industrially developed country, the High Technology on Environmental Protection research of China's foundry industry is also comparatively backward.At present, China also mainly concentrates on the flue gas of cupola furnace and the dust pollution aspect that casting process produces to foundry industry air-polluting understanding, and the larger VOC of harm and HAP air pollutants shortage are fully realized, many-sided systematic studyes such as source, composition, monitoring and the pollution control technology to VOC and HAP in casting tail gas are not all also carried out comprehensively.

Summary of the invention

Technical matters to be solved by this invention is to provide a kind of harvester and method of sand casting tail gas, and the pollution-free collection that can be used for foundry enterprise and Scientific Research in University Laboratory and cast tail gas lays the foundation for follow-up exhaust gas component detects.

The harvester of sand casting tail gas of the present invention, comprise pouring furnace, on the bell of pouring furnace, be placed with pouring platform, on pouring platform, place the sandbox that sand mold is housed, seal closure comprises sandbox wherein and is tightly connected with pouring platform, gas pressure sensor, evacuation passageway and gas acquisition channel are housed on described seal closure, on described gas collecting passage, are connected with electric pumping device;

Also comprise stalk, through bell and pouring platform, be communicated with molten metal and sandbox in pouring furnace;

Also comprise inert gas passage, be communicated with pouring furnace and outside inertia source of the gas.

In described pouring furnace, comprise crucible, furnace lining, heater coil, heat-insulation layer.

Stalk posts plastic closures film before the cast of seal closure inner port.

The present invention also provide adopt said apparatus the acquisition method of sand casting tail gas, comprise the steps:

1) melted molten metal is sent into and in pouring furnace, be incubated to be pouredly, in pouring furnace, pass into inert gas;

2) the good sandbox of moulding is put on pouring platform, covered seal closure, seal closure is fixed on pouring platform, stalk posts plastic closures film before the cast of seal closure inner port.

3) open vacuum pump, extract the gas in seal closure, close vacuum pump after reaching vacuum tightness 0.01 ~ 0.02MPa;

4) open the gas pressure sensor on seal closure, in pouring furnace, pass into inert gas, under inert gas pressure effect, molten metal is poured into a mould from below to up by stalk;

5) after the gaseous tension in seal closure reaches gas pressure sensor preset value 0.05-0.1MPa, sensor is reported to the police, and opens electronic air extracting pump, extracts gas in seal closure and, to gas sampling bag, prepares against late detection.

The acquisition method of described sand casting tail gas, in step 4), the pressure limit control of inert gas is 0.05-0.3 MPa.

The acquisition method of described sand casting tail gas, the inert gas passing in pouring furnace is CO ₂or Ar.

The acquisition method of described sand casting tail gas, the molten metal of cast is cast iron, cast steel, aluminium alloy, magnesium alloy, the aldary that is applicable to sand casting.

The present invention is directed to the collection of the tail gas in sand casting, developed sand casting tail gas harvester and method, for casting the pollution-free collection of tail gas, for follow-up exhaust gas component accurately detects and lays the foundation.Tail gas harvester small volume of the present invention, is applicable to the laboratory operation of foundry enterprise and colleges and universities, has simple in structurely, easy to operate, and tail gas gathers free of contamination feature.

Accompanying drawing explanation

Fig. 1 is the schematic diagram of gas collecting device involved in the present invention; Wherein 1 is gas pressure sensor, and 2 is seal closure, and 3 is stalk, 4 is sandbox, and 5 is inert gas passage, and 6 is bell, 7 is pouring furnace, and 8 is heat-insulation layer, and 9 is heater coil, 10 is furnace lining, and 11 is crucible, and 12 is molten metal, 13 is pouring platform, and 14 is sand mold, and 15 is gas collecting passage, 16 is evacuation passageway, and 17 is electric pumping device.

Embodiment

Realize the device of sand casting tail gas collection as shown in Figure 1, comprise pouring furnace 7, on the bell 6 of pouring furnace 7, be placed with pouring platform 13, on pouring platform, place the sandbox 4 that sand mold 14 is housed, seal closure 2 comprises sandbox 4 wherein and is tightly connected with pouring platform 13, gas pressure sensor 1, evacuation passageway 16 and gas acquisition channel 15 are housed on described seal closure 2, on described gas collecting passage 15, are connected with electric pumping device 17;

Also comprise stalk 3, through bell 6 and pouring platform 13, be communicated with molten metal 12 and sandbox 4 in pouring furnace 7;

Also comprise inert gas passage 5, be communicated with pouring furnace 7 and outside inertia source of the gas.

Embodiment 1:

The crucible that is contained with melted molten metal is put into pouring furnace and be incubated to be pouredly, in pouring furnace, be filled with CO ₂blanket gas, puts into the sandbox of having made type to note on formula pouring platform, covers seal closure, and seal closure is fixed on pouring platform, opens vacuum pump, extracts the gas in seal closure, and the vacuum tightness in seal closure is closed vacuum pump after reaching 0.01MPa.Open the gas pressure sensor on seal closure, in pouring furnace, pass into the CO of controllable pressure ₂gas, pressure is 0.15MPa, make under pressure molten metal pour into a mould by stalk from below to up, sand mold in seal closure starts to get angry under high temperature action, in the time that the gaseous tension in seal closure reaches 0.05MPa, sensor is reported to the police, and opens electronic air extracting pump, extract gas in seal closure and, to gas sampling bag, prepare against late detection.

Embodiment 2:

The crucible that is contained with melted molten metal is put into pouring furnace to be incubated to be poured; in pouring furnace, be filled with Ar blanket gas; the sandbox of having made type is put into and noted on formula pouring platform; cover seal closure; seal closure is fixed on pouring platform; open vacuum pump, extract the gas in seal closure, the vacuum tightness in seal closure is closed vacuum pump after reaching 0.02MPa.Open the gas pressure sensor on seal closure, in pouring furnace, pass into the Ar gas of controllable pressure, pressure is 0.5MPa, make under pressure molten metal pour into a mould by stalk from below to up, the sand mold in seal closure starts to get angry under high temperature action, in the time that the gaseous tension in seal closure reaches 0.1MPa, sensor is reported to the police, open electronic air extracting pump, extract gas in seal closure and, to gas sampling bag, prepare against late detection.

Claims

1. A collection device for sand casting tail gas, characterized in that it comprises a pouring furnace (7), a pouring table (13) is placed on the furnace cover (6) of the pouring furnace (7), and a device is placed on the pouring table (13). A sand box (4) with a sand mold (14), the sealing cover (2) contains the sand box (4) and is sealed with the pouring table (13), and the sealing cover (2) is equipped with a gas pressure sensor (1) , a vacuuming channel (16) and a gas collection channel (15), the gas collection channel (15) is connected with an electric pumping device (17);

It also includes a riser pipe (3), which passes through the furnace cover (6) and the pouring table (13), and communicates with the molten metal (12) and the sand box (4) in the pouring furnace (7);

It also includes an inert gas channel (5) communicating with the pouring furnace (7) and an external inert gas source.

2 . The collection device according to claim 1 , wherein the pouring furnace includes a crucible, a furnace lining, a heating coil and an insulating layer. 3 .

3. the method for collecting sand casting tail gas using the collection device described in claim 1, comprises the steps:

1) Send the smelted molten metal into the pouring furnace to keep warm and wait for pouring, and inert gas is introduced into the pouring furnace;

2) Put the molded sand box on the pouring table, cover the sealing cover, fix the sealing cover on the pouring table, and stick the plastic sealing film on the rising pipe before pouring at the inner port of the sealing cover;

3) Turn on the vacuum pump, extract the gas in the sealing cover, and turn off the vacuum pump after reaching a vacuum degree of 0.01~0.02MPa;

4) Open the gas pressure sensor on the sealing cover, pass inert gas into the pouring furnace, and under the action of the pressure of the inert gas, the molten metal is poured through the riser from bottom to top;

5) When the gas pressure in the sealed cover reaches the preset value of 0.05-0.1MPa of the gas pressure sensor, the sensor will alarm, turn on the electric air pump, and pump the gas in the sealed cover into the gas sampling bag for later detection.

4. The collection method according to claim 3, characterized in that the pressure range of the inert gas in step 4) is controlled to be 0.05-0.3 MPa.

5. The collection method according to claim 3, characterized in that, in the collection method of the sand casting tail gas, the inert gas fed into the pouring furnace is CO ₂ or Ar.

6. The collection method according to claim 3, characterized in that the molten metal is cast iron, cast steel, aluminum alloy, magnesium alloy or copper alloy.