Lost foam casting sand treatment method

Abstract

The invention provides an evanescent mode casting sand treatment method, belongs to the technical field of evanescent mode sand treatment, and overcomes the technical defect that the existing sand treatment speed is slow, the treatment method comprises the following steps: casting sand is layered through vibration of a vibrating screen, and large-particle materials enter a material barrel through an upper-layer screen of the vibrating screen; box burying sand and fine dust enter a sand suction hopper; a negative pressure area is formed through an inverted cone space in the cyclone processor and a cylindrical sand suction barrel which is inversely buckled at the upper part, and sand and fine dust are cooled and separated under the action of cyclone and then are discharged from different paths respectively; according to the method, through the cyclone processor and the sand suction barrel, not only can the mold sand be cooled, but also sand grains and sand ash can be separated, and the working efficiency of evanescent mold sand treatment is improved; cold air is sucked in a plurality of pipelines communicated with the upper surface in a conical hopper in the cyclone processor, so that the cooling effect is further improved; the scattered sand can be further cooled through flowing of air of the bucket elevator.

Description

Technical Field

[0001] The invention belongs to the technical field of lost foam sand processing, and particularly relates to a lost foam casting sand processing method. Background Art

[0002] Lost foam casting is a new casting method that combines paraffin or foam models with similar size and shape to the casting into a model cluster, brushes refractory coating and dries it, buries it in dry quartz sand for vibration molding, pours it under negative pressure, vaporizes the model, and the liquid metal occupies the position of the model, solidifies and cools to form a casting. This process does not require mold removal, no parting surface, no sand core, so the casting has no flash, burrs and draft angle, and reduces the dimensional error caused by the core combination. Therefore, in the past 20 years, the lost foam casting technology has developed rapidly worldwide. The important material needed in the lost foam casting process is the pearl sand.

[0003] However, in the prior art, the sand box is simply placed directly on the vibrating screen and opened, the pearl sand is leaked to the discharge port of the vibrating screen, and the castings are manually collected. The temperature of the collected pearl sand is high and not conducive to storage, and the collected pearl sand contains more impurities.

[0004] In Chinese patent literature, there is a patent document with publication number CN 214079103 U, entitled "An Energy-Saving Lost Foam Sand Processing Equipment", which solves the above problems. The utility model relates to an energy-saving lost foam sand processing equipment, comprising a screen, a vibrating screen, a first lifting mechanism, a storage cylinder, a drum radiator, a cooling mechanism, a second lifting mechanism and a sand storage box, wherein the vibrating screen is connected below the screen, the vibrating screen has a gem sand discharge port and an impurity discharge port, the impurity discharge port is connected to the impurity collecting mechanism, the gem sand discharge port is connected to the first lifting mechanism, the output end of the first lifting mechanism is connected to the storage cylinder, the output end of the storage cylinder is connected to a conveying pipe, the conveying pipe is connected to one of the bottom surfaces of the drum radiator, the other bottom surface of the drum radiator has a discharge port, the discharge port is connected to the input end of the second lifting mechanism, the output end of the second lifting mechanism is connected to the sand storage box, a sand storage pipe is connected below the sand storage box, and a sealing plate is provided at the bottom of the sand storage pipe, wherein the drum radiator is rotatably arranged, and the cooling mechanism is used to cool the drum for heat dissipation.

[0005] However, the above patent documents use water for cooling, which has a slow cooling speed, makes it difficult to solve the pipeline sealing problem, and makes it difficult to separate the sand and ash. How to quickly cool the sand and ash and separate them is a technical problem that we urgently need to solve. Summary of the invention

[0006] The purpose of the present invention is to provide a lost foam casting sand processing method to solve the above technical problems existing in the prior art.

[0007] According to the above purpose, the technical solution of the present invention is: a lost foam casting sand processing method, characterized in that: the processing method comprises the following steps:

[0008] Step 1: The foundry sand is vibrated by a vibrating screen to be layered, and the large particles enter the material bucket through the upper screen of the vibrating screen, and the buried sand and fine dust enter the sand suction hopper;

[0009] Step 2, the buried box sand and fine dust in the sand suction hopper are sucked into the first cyclone processor through a suction pipe;

[0010] Step 3: A negative pressure zone is formed by the inverted cone space inside the cyclone processor and the inverted cylindrical sand suction bucket on the top. Under the action of the cyclone, the sand and fine dust are cooled and separated and discharged from different paths;

[0011] Step 4, sucking the sand processed by the first cyclone into the second cyclone processor through a straw;

[0012] Step 5, the small sand particles in the second cyclone processor enter the dust collector air duct through the sand suction bucket on the upper part of the cyclone processor, and the large sand particles flow into the bucket elevator through the inner cone bucket of the cyclone processor under the action of gravity;

[0013] Step 6: The bucket elevator lifts the sand to the top of the sand storage and dumps it into the sand storage;

[0014] Step 7, conveying the sand in the sand storage to the sand box on the three-dimensional vibration compaction table through a screw conveyor for box pouring;

[0015] Step 8, repeat the above steps repeatedly.

[0016] Furthermore, in step 1, the foundry sand is filtered through the filter screen of the sand dropping hopper and then flows into the vibrating screen to separate the coarse debris.

[0017] Furthermore, in step 2, the sand suction hopper is divided into two parts, the left part and the right part, which have different heights. The bottom of the left part, which serves as a suction pipe, is lower, and the bottom of the right part, which receives the buried box sand, is higher than the left part, so that the sand flows into the left part conveniently.

[0018] Furthermore, in step 3, the cyclone processor is provided with an involute suction pipe, which is connected to an external suction pipe through a pipe opening to form a cyclone channel.

[0019] Furthermore, in step 3, the small sand particles in the first cyclone processor enter the dust collector air duct through the sand suction bucket on the upper part of the cyclone processor, and the large sand particles flow into the second sand suction hopper through the inner cone hopper of the cyclone processor under the action of gravity.

[0020] Furthermore, the inner cone bucket of the cyclone processor also includes a step of further cooling the falling sand by sucking cold air through a plurality of pipes connected to the upper surface of the cyclone processor.

[0021] Furthermore, the dust collector air duct in step 5 is the same as the dust collector air duct in step 3, and is connected to the upper parts of the two sand suction buckets through pipelines.

[0022] Furthermore, a butterfly valve switch is provided on the upper part of the two sand suction buckets in step 3 and step 5, and the butterfly valve switch is used to control the opening and closing of the dust collector air duct or the size of the control channel.

[0023] Furthermore, in step 6, the sand storage is a cube, and its lower part is connected to the screw conveyor through a quadrangular pyramid funnel.

[0024] Furthermore, in step 7, the three-dimensional vibration compaction table reduces the space between the sand in the sand box by vibrating the side and bottom vibrators.

[0025] Compared with the prior art, the advantages and beneficial effects of the present invention are:

[0026] 1. The method of the present invention comprises the step of sucking the sand in the sand suction hopper into the first cyclone processor through a suction pipe. The cyclone processor and the sand suction bucket can not only cool the molding sand, but also separate the sand particles and sand ash, thereby improving the working efficiency of the lost foam sand processing;

[0027] 2. The inner cone bucket of the cyclone processor in the method of the present invention further includes a step of further cooling the falling sand by sucking cold air through a plurality of pipes connected to the upper surface of the cyclone processor, thereby further reducing the temperature of the cyclone-precipitated sand and further improving the cooling effect;

[0028] 3. The method of the present invention has the characteristics of conveying the sand treated by the second cyclone processor to the top of the sand bin through a bucket elevator and scattering it into the sand bin, and the scattered sand can be further cooled by the flow of air. DETAILED DESCRIPTION

[0029] The present invention discloses a lost foam casting sand processing method, and the processing method comprises the following steps: step 1, the casting sand is vibrated by a vibrating screen to be layered, the large particle material enters the material bucket through the upper screen of the vibrating screen, the buried box sand and fine dust enter the sand suction hopper, the casting sand is filtered through the filter screen of the sand falling hopper and then flows into the vibrating screen to separate the coarse and large debris; step 2, the sand in the sand suction hopper is sucked into the first cyclone processor through a suction pipe, the sand suction hopper is divided into left and right parts, the two parts are of different heights, the left part as the suction pipe has a lower bottom, and the right part as the receiving buried box sand has a higher bottom than the left part, which is convenient The sand flow falls into the left part. The cyclone processor is provided with an involute suction pipe, which is connected to an external suction pipe through a pipe mouth to form a cyclone channel. The cyclone processor forms a negative pressure zone through an inverted cone space and an inverted cylindrical sand suction bucket on the upper part, and the sand and fine dust are separated and discharged from different paths respectively; Step 3, the small sand particles in the first cyclone processor enter the dust collector air duct through the sand suction bucket on the upper part of the cyclone processor, and the large sand particles flow into the second sand suction bucket through the cone bucket in the cyclone processor under the action of gravity. A butterfly valve switch is provided on the upper part of the sand suction bucket. The control is to open or close the dust collector air duct or control the size of the channel; step 4, the sand in the second sand suction hopper is sucked into the second cyclone processor through the suction tube; step 5, the sand with small particles in the second cyclone processor enters the dust collector air duct through the sand suction bucket on the upper part of the cyclone processor, and the sand particles with large particles flow into the bucket elevator through the inner cone bucket of the cyclone processor under the action of gravity. The inner cone bucket of the cyclone processor also includes a step of further cooling the falling sand by sucking cold air through multiple pipes connected to the upper surface of the cyclone processor. The dust collector air duct is the same air duct as the dust collector air duct in step 3. The two sand suction buckets are connected to the upper part through pipelines respectively. The upper part of the sand suction bucket is provided with a butterfly valve switch, and the butterfly valve switch is used to control the opening, closing or size of the dust collector air duct; Step 6, the bucket elevator lifts the sand to the top of the sand storage and dumps it into the sand storage. The sand storage is a cube, and its lower part is connected to the screw conveyor through a four-sided pyramid funnel; Step 7, the sand in the sand storage is transported to the sand box on the three-dimensional vibration table through the screw conveyor for box pouring. The three-dimensional vibration table vibrates the side and bottom vibrators to reduce the existence of gaps between the sand in the sand box; Step 8, the above steps are repeated.

[0030] During operation, the lost foam is to recycle the buried box filling material by physically cooling it and removing impurities. At present, the buried box materials used by manufacturers are mainly pearl sand, quartz sand, olive sand, etc. In the production process, the buried box sand is sucked out of the air in the sand box by a vacuum pump to harden the sand in the sand box under negative pressure (to achieve the purpose of modeling), and then the molten steel is injected into the cavity through the gate. When the casting is cooled to the process temperature, the box is turned over. At this time, the temperature of the buried box sand exceeds 120℃, and locally exceeds 250℃. The buried box sand flows into the vibrating screen through the sand falling hopper, and the large particles enter the material barrel through the screen composed of ribs on the upper layer of the vibrating screen, and the buried box sand and fine dust enter the sand suction hopper. The first-stage cyclone sucks the buried sand and dust in the sand suction hopper into the barrel of the cyclone processor. The buried sand falls into the inner cavity of the cone inside the cyclone cone after cyclone processing. The sand outlet at the bottom of the inner cavity of the cone flows into the second-stage sand suction hopper through a pipe, and the fine dust enters the dust collector air duct through the cyclone outlet pipe. At this time, the sand temperature in the second-stage sand suction hopper does not meet the requirements for reuse. The second-stage cyclone sucks the sand in the sand suction hopper again into another cyclone processor for further processing. At this time, the clean sand that has been processed and the temperature reaches room temperature flows into the bucket elevator through a pipe. The bucket elevator lifts the sand to the sand storage for storage. The operator transports the sand to the lost foam sand box on the three-dimensional vibration table through the screw conveyor at the bottom of the sand storage. At this time, the sand temperature in the sand box has dropped below 50 degrees, which meets the requirements for reuse and can be boxed and poured again, and the cycle is repeated.

[0031] The specific embodiments described herein are merely examples of the spirit of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in similar ways, but they will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

[0032] The above is an introduction to the lost foam casting sand processing method provided by the present invention. In the introduction, specific preferred embodiments are used to illustrate the principles and implementation methods of the present invention. These embodiments are only used to help understand the principles and core ideas of the present invention. It should be pointed out that for ordinary technicians in this field, without departing from the design ideas of the present invention, the implementation schemes in the above embodiments can be further combined or replaced, and the present invention can be improved and modified in a number of ways. These improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. A lost foam casting sand processing method, characterized in that: The foundry sand processing method comprises the following steps: Step 1: The foundry sand is vibrated by a vibrating screen to be layered, and the large particles enter the material bucket through the upper screen of the vibrating screen, and the buried sand and fine dust enter the sand suction hopper; Step 2, the buried box sand and fine dust in the sand suction hopper are sucked into the first cyclone processor through a suction pipe; Step 3: A negative pressure zone is formed by the inverted cone space inside the cyclone processor and the inverted cylindrical sand suction bucket on the top. Under the action of the cyclone, the sand and fine dust are cooled and separated and discharged from different paths; Step 4, sucking the sand processed by the first cyclone into the second cyclone processor through a straw; Step 5, the small sand particles in the second cyclone processor enter the dust collector air duct through the sand suction bucket on the upper part of the cyclone processor, and the large sand particles flow into the bucket elevator through the inner cone bucket of the cyclone processor under the action of gravity; Step 6: The bucket elevator lifts the sand to the top of the sand storage and dumps it into the sand storage; Step 7, conveying the sand in the sand storage to the sand box on the three-dimensional vibration table through a screw conveyor for box pouring; Step 8, repeat the above steps repeatedly.

2. The lost foam casting sand processing method according to claim 1, characterized in that: In step 1, the foundry sand is filtered through the filter screen of the sand dropping hopper and then flows into the vibrating screen to separate the coarse debris.

3. The lost foam casting sand processing method according to claim 1, characterized in that: In step 2, the sand suction hopper is divided into two parts, the left part and the right part, which have different heights. The bottom of the left part, which serves as a suction pipe, is lower, and the bottom of the right part, which receives the buried box sand, is higher than the left part, so that the sand flows into the left part conveniently.

4. The lost foam casting sand processing method according to claim 1, characterized in that: In step 3, the cyclone processor is provided with an involute suction pipe, which is connected to an external suction pipe through a pipe opening to form a cyclone channel.

5. The lost foam casting sand processing method according to claim 1, characterized in that: In step 3, the small sand particles in the first cyclone processor enter the dust collector air duct through the sand suction bucket on the upper part of the cyclone processor, and the large sand particles flow into the second sand suction hopper through the inner cone hopper of the cyclone processor under the action of gravity.

6. The lost foam casting sand processing method according to claim 5, characterized in that: The inner cone bucket of the cyclone processor also includes a step of further cooling the falling sand by sucking cold air through a plurality of pipes connected to the upper surface of the cyclone processor.

7. The lost foam casting sand processing method according to claim 1, characterized in that: The dust collector air duct in step 5 is the same as the dust collector air duct in step 3, and is connected to the upper parts of the two sand suction buckets through pipelines.

8. The lost foam casting sand processing method according to claim 1, characterized in that: A butterfly valve switch is provided on the upper part of the two sand suction buckets in step 3 and step 5, and the butterfly valve switch is used to control the opening and closing of the dust collector air duct or the size of the control channel.

9. The lost foam casting sand processing method according to claim 1, characterized in that: In step 6, the sand storage is a cube, and its lower part is connected to the screw conveyor through a quadrangular pyramid funnel.

10. The lost foam casting sand processing method according to claim 1, characterized in that: In step 7, the three-dimensional vibration compaction table reduces the space between the sand in the sand box by vibrating the side and bottom vibrators.