Summary of the invention
In view of the above-mentioned deficiencies in the prior art, the technical problem to be solved by the present invention is that it is autochthonal to provide a kind of improvement
Equipment is produced, simple structure and reasonable design and easy to operate guarantees the continuously and effectively operation of production equipment, improves finished product
The uniformity of the partial size of conditioned soil, it is practical.
In order to solve the above technical problems, the technical solution adopted by the present invention is that: a kind of conditioned soil production equipment, feature exist
In: including pulverizer, the sub-material transmission mechanism being connect with the pulverizer, the rabbling mechanism being connect with the sub-material transmission mechanism
The vibration screening mechanism connecting with the rabbling mechanism, the pulverizer includes body, the hack that is arranged on the body
Storehouse and the hack transmission belt that the hack storehouse outlet is arranged in, the sub-material transmission mechanism include that setting is separate in hack transmission belt
The first sub-material transmission assembly and the second sub-material transmission assembly of described body one end and setting are in the first sub-material transmission group
Part and the hack of the second sub-material transmission assembly bottom hold feed bin, and the first sub-material transmission assembly includes the first tripper
With first point of transmission belt that the first tripper bottom is arranged in, the second sub-material transmission assembly includes the second tripper and setting
Second point of transmission belt in the second tripper bottom, the hack hold feed bin and are located at first point of transmission belt and second point of biography
The bottom of defeated band, the rabbling mechanism includes a mixing bowl, be arranged in a mixing bowl and that hack is held between bin bottom is first total
Transmission belt and second total transmission belt being arranged between a mixing bowl and vibration screening mechanism;
The vibration screening mechanism includes the discharging sieve mechanism that second total transmission belt discharge end is arranged in, is arranged described
Discharge the elastic support of sieve actuator base and the vibratory drive mechanism of the driving discharging sieve mechanism vibrations, the material screen out
The inclined laying of net mechanism, the height of the upper end of the discharging sieve mechanism are greater than the height of the lower end of the discharging sieve mechanism
The lower end of degree, the discharging sieve mechanism is provided with multiple discharge ports.
Above-mentioned a kind of conditioned soil production equipment, it is characterised in that: the discharging sieve mechanism includes main body frame, multiple
The fixation steel bar laid along the main body frame width direction and the discharging sieve being mounted on fixed steel bar, the discharging sieve
Top surface be lower than the top of the main body frame, the main body frame and the inclined laying of the discharging sieve, the body frame
The height of the upper end of frame is greater than the height of the lower end of the main body frame, and multiple discharge ports are located at the lower end of main body frame.
Above-mentioned a kind of conditioned soil production equipment, it is characterised in that: the vibratory drive mechanism includes driving motor and institute
The transmission shaft of driving motor output shaft transmission connection is stated, the both ends that the transmission shaft wears out the discharging sieve mechanism symmetrically cover
Equipped with eccentric wheel.
Above-mentioned a kind of conditioned soil production equipment, it is characterised in that: the transmission shaft and the driving motor output shaft pass
One end of dynamic connection is provided with split axle connector flange and split axle connector, is provided in the discharging sieve mechanism for transmission shaft
The transmission shaft flange worn.
Above-mentioned a kind of conditioned soil production equipment, it is characterised in that: along main body frame length direction on the main body frame
Multiple reinforcing rods are provided with, the fixed steel bar is mounted on reinforcing rod, the fixed steel bar and the perpendicular laying of reinforcing rod;Institute
It states two sides at the top of main body frame and is provided with high baffle, the discharge port is provided with waste tank.
A kind of above-mentioned conditioned soil production equipment, it is characterised in that: the elastic support include four setting it is described go out
The spring legs of material screen net actuator base quadrangle, the spring legs include the main body frame heel brace from top to bottom successively laid,
Spring and pedestal.
Above-mentioned a kind of conditioned soil production equipment, it is characterised in that: the access opening top in the hack storehouse is provided with into material screen
Net and the eccentric motor for driving the vibration of pan feeding sieve, the top laying at an acute angle of the pan feeding sieve and the hack storehouse;It is described
Multiple spraying head type spray heads are arranged in the entrance interval of a mixing bowl.
Meanwhile a kind of the invention also discloses method and steps simple, design rationally and realizes conditioned soil convenient, that effect is good
Production method, which is characterized in that method includes the following steps:
Step 1: the broken and sub-material transmission of soil block:
Soil block is put into hack storehouse by step 101 using loading parts, and during soil block enters hack storehouse, partially
Electrocardiograph drives the vibration of pan feeding sieve, is screened and is entered in hack storehouse by pan feeding sieve;
Step 102 is crushed the soil block entered in hack storehouse using the pulverizer, obtains hack;
Step 103 is transmitted hack obtained in step 102 using the hack transmission belt in the pulverizer;
Step 2: the transmission of hack:
Hack in step 201, hack transmission belt enters the first tripper and the second tripper, into the first tripper
Hack enters first point of transmission belt by the first tripper bottom, and the hack into the second tripper passes through the second tripper bottom
Into second point of transmission belt;
Step 202 enters hack and holds feed bin into the hack of first point of transmission belt and second point of transmission belt, contains from hack
The hack that discharge bin bottom comes out enters first total transmission belt;
Step 3: the production and transmission of conditioned soil:
Step 301 is transmitted to a mixing bowl into the hack of first total transmission belt, at the same add into a mixing bowl cement and
Water stirs evenly, and obtains conditioned soil;
Step 302, the conditioned soil come out from a mixing bowl bottom enter second total transmission belt, and transmit through second total transmission belt
To the discharging sieve mechanism;
Step 4: the vibration screening of conditioned soil:
The vibratory drive mechanism drives the discharging sieve mechanism vibrations, makes to enter in the discharging sieve mechanism less
Enter the collection hopper by the discharging sieve mechanism in the conditioned soil of Particle size requirements value, meanwhile, make to enter the discharging
Greater than the conditioned soil of Particle size requirements value under the action of self-weight along the discharging sieve mechanism in conditioned soil in sieve mechanism
Inclined surface slides until being discharged by the discharge port, and be collected by the waste tank.
Above-mentioned method, it is characterised in that: the biography of first point of transmission belt described in step 201 and second point of transmission belt
Movement Capabilities are 300t/h~600t/h, and the transmittability of first total transmission belt and the transmittability of second total transmission belt are
300t/h~600t/h.
Above-mentioned method, it is characterised in that: grogs of the granularity no more than 1cm~2cm accounts in hack described in step 102
90wt% or more;
In step 301 in a mixing bowl the mass percent of cement, water and hack be respectively cement 2%~8%, water 15%~
18%, surplus is hack.
Compared with the prior art, the present invention has the following advantages:
1, improved production device structure of the present invention is simple and realizes that conveniently, input cost is lower.
2, improved production equipment of the present invention is at low cost only with a pulverizer, and reduces crossed construction interference, is convenient for field
Ground installation, and guarantee production efficiency.
3, sub-material transmission mechanism used by improved production equipment of the present invention includes hack transmission belt far from the body one
The first sub-material transmission assembly and the second sub-material transmission assembly at end are improved broken by the way that two sub-material transmission parts are arranged
The delivery efficiency of native machine, and can be in any sub-material transmission assembly failure, another sub-material transmission assembly remains to work normally, and guarantees
Whole production continues normally to produce.
4, vibration screening mechanism of the present invention is located at total transmission belt discharge end, is in order to total transmission belt discharge end
Conditioned soil further screen, guarantee finished product conditioned soil partial size uniformity.
5, vibration screening mechanism used by improved production equipment of the present invention includes discharging sieve mechanism, elastic support and vibration
Dynamic driving mechanism drives elastic support to vibrate up and down by vibratory drive mechanism, and elastic support, which vibrates up and down, drives discharging sieve
Mechanism vibrates up and down, and during the sieve mechanism that discharges vibrates up and down, is on the one hand convenient for will be greater than the improvement of Particle size requirements value
Soil is collected to be produced and processed again, on the other hand, convenient for the conditioned soil by Particle size requirements are met in the case where the process of vibration is convenient for
Collection is fallen, the raising of conditioned soil uniformity and the reduction of cost is realized, meets construction requirement.
6, improved production method structure of the present invention is simple, and design rationally, reduces crossed construction interference, improves efficiency, drop
Low security risk and equipment investment, and the efficiency for the process of mixing and stirring of gathering materials is improved, and production process control is strengthened, and is met
Construction requirement, improves the uniformity of the partial size of finished product conditioned soil, practical.
In conclusion the configuration of the present invention is simple, design are reasonable and easy to operate, guarantee the continuous and effective of improved production equipment
Ground operation, improves the uniformity of the partial size of finished product conditioned soil, practical.
Below by drawings and examples, technical scheme of the present invention will be described in further detail.
Specific embodiment
A kind of conditioned soil production equipment as shown in Figure 1 to Figure 3, including pulverizer, the sub-material being connect with the pulverizer
Transmission mechanism, the rabbling mechanism being connect with the sub-material transmission mechanism and the vibration screening mechanism being connect with the rabbling mechanism
19, the pulverizer includes that body 20, the hack storehouse 21 being arranged on the body 20 and setting export in the hack storehouse 21
Hack transmission belt 25, the sub-material transmission mechanism includes hack transmission belt 25 is arranged in far from described 20 one end of body first
Sub-material transmission assembly and the second sub-material transmission assembly and setting are passed in the first sub-material transmission assembly and second sub-material
The hack of defeated component bottom holds feed bin 30, and the first sub-material transmission assembly includes the first tripper 28 and is arranged at first point
First point of transmission belt 29 of 28 bottom of glassware, the second sub-material transmission assembly include the second tripper 27 and are arranged at second point
Second point of transmission belt 26 of 27 bottom of glassware, the hack hold feed bin 30 and are located at first point of transmission belt 29 and second point of biography
The bottom of defeated band 26, the rabbling mechanism include a mixing bowl 18, setting held between 30 bottom of feed bin in a mixing bowl 18 and hack
First total transmission belt 16 and second total transmission belt 17 for being arranged between a mixing bowl 18 and vibration screening mechanism 19;
The vibration screening mechanism 19 exists including the discharging sieve mechanism of second total 17 discharge end of transmission belt is arranged in, is arranged
It is described discharging sieve actuator base elastic support and drive it is described discharging sieve mechanism vibrations vibratory drive mechanism, it is described go out
The inclined laying of material screen net mechanism, the height of the upper end of the discharging sieve mechanism are greater than the lower end of the discharging sieve mechanism
Highly, the lower end of the discharging sieve mechanism is provided with multiple discharge ports 14.
In the present embodiment, the discharging sieve mechanism includes main body frame 4, multiple along 4 width direction of main body frame
The top surface of the fixation steel bar 2 of laying and the discharging sieve 1 being mounted on fixed steel bar 2, the discharging sieve 1 is lower than the main body
The top of frame 4, the main body frame 4 and the inclined laying of the discharging sieve 1, the height of the upper end of the main body frame 4
Greater than the height of the lower end of the main body frame 4, multiple discharge ports 14 are located at the lower end of main body frame 4.
In the present embodiment, the vibratory drive mechanism includes that driving motor and the driving motor output shaft are sequentially connected
Transmission shaft 7, the both ends that the transmission shaft 7 wears out main body frame 4 are symmetrically arranged with eccentric wheel 8.
In the present embodiment, one end of the transmission shaft 7 and driving motor output shaft transmission connection is provided with split axle company
Device flange 10 and split axle connector 9 are connect, the transmission shaft flange 15 worn for transmission shaft 7 is provided on the main body frame 4.
In the present embodiment, 4 length direction of main body frame is provided with multiple reinforcing rods 6 on the main body frame 4, it is described solid
Determine steel bar 2 to be mounted on reinforcing rod 6, the fixed steel bar 2 and the perpendicular laying of reinforcing rod 6;The 4 top two sides of main body frame
It is provided with high baffle 3, the discharge port 14 is provided with waste tank.
In the present embodiment, the elastic support includes four spring legs that 4 bottom four corners of main body frame are arranged in, described
Spring legs include the main body frame heel brace 11, spring 12 and pedestal 13 from top to bottom successively laid.
In the present embodiment, the access opening top in the hack storehouse 21 is provided with pan feeding sieve 22 and pan feeding sieve 22 is driven to vibrate
Eccentric motor 23, the top laying at an acute angle of the pan feeding sieve 22 and the hack storehouse 21;The entrance of a mixing bowl 18
Multiple spraying head type spray heads 24 are arranged in interval.
In the present embodiment, it includes that the first sub-material transmission assembly and second sub-material are transmitted that the sub-material transmission mechanism, which is arranged,
Component improves the delivery efficiency of pulverizer, and can be in any sub-material transmission assembly event by the way that two sub-material transmission parts are arranged
When barrier, another sub-material transmission assembly remains to work normally, and guarantees that whole production continues normally to produce.
In the present embodiment, setting vibration screening mechanism 19 includes discharging sieve mechanism, elastic support and vibratory drive mechanism,
Elastic support is driven to vibrate up and down by vibratory drive mechanism, the elastic support, which vibrates up and down, drives discharging sieve mechanism or more
On the one hand vibration passes through during the sieve mechanism that discharges vibrates up and down convenient for will be greater than the conditioned soil of Particle size requirements value
Material mouth is collected to be produced and processed again, on the other hand, convenient for will meet the conditioned soil of Particle size requirements value vibration process just
It is collected in falling, realizes the raising of conditioned soil uniformity and the reduction of cost, meet construction requirement.
In the present embodiment, the inclined laying of the discharging sieve mechanism, the height of the upper end of the discharging sieve mechanism are set
Degree be greater than it is described discharging sieve mechanism lower end height, first, be in order to enter it is described discharging sieve mechanism in conditioned soil
In be greater than Particle size requirements value conditioned soil under the action of self-weight, can along discharging sieve mechanism inclined surface slide until through going out
Material mouth 14 is collected production of living again by the waste tank;Second, it is in order in the conditioned soil entered in the discharging sieve mechanism
It can glide under Gravitative Loads, conditioned soil is avoided to accumulate and be not easy to screen;Third is in order to inclined in discharging sieve mechanism
When laying, the space on discharging sieve mechanism top is effectively utilized, improves the capacity of the discharging received conditioned soil of sieve mechanism;
4th, it is the gravity in order to reduce application of the conditioned soil to the discharging sieve mechanism, improves the discharging sieve mechanism
Bearing capacity.
In the present embodiment, the setting of elastic support, first, it is in order in the mistake of the discharging sieve mechanism carrying conditioned soil
Cheng Zhongyou certain buffering avoids the gravity of application of the conditioned soil to the discharging sieve mechanism larger, causes the material screen out
The damage of net mechanism;Second, it is to subtract during vibratory drive mechanism drives the discharging sieve mechanism to vibrate up and down
The amplitude vibrated less avoids the conditioned soil Oscillation Amplitude in the discharging sieve mechanism larger and is detached from the discharging screening machine
Structure;Third, be in order to vibratory drive mechanism drive the discharging sieve mechanism vibrate up and down during, can drive described in out
Material screen net mechanism is further vibrated, and is increased the movement of conditioned soil screening, is improved screening efficiency;4th, it is to increase
The height of discharging sieve mechanism is stated, is mounted on discharge port end convenient for the discharging sieve mechanism, and convenient in the discharging sieve
The bottom of mechanism is installed by conditioned soil collection hopper.
In the present embodiment, the setting of main body frame 4 is for the ease of the installation for the sieve 1 that discharges, convenient for setting for discharge port 14
It sets, and is convenient for the installation of transmission shaft 7, effectively utilize the structure of main body frame 4, so that mechanism is compact, and realize convenient, cost
It is low.
In the present embodiment, the setting of fixed steel bar 2 and reinforcing rod 6, be in order to which the bottom to discharging sieve 1 reinforces,
Improve the compression strength of discharging sieve 1.
In the present embodiment, multiple discharge ports 14 are set, and two neighboring discharge port 14 is not connected to, are to be sieved in conditioned soil
During choosing and whereabouts, when the conditioned soil for meeting partial size has not enough time to screening, it can be deposited in the lower end of main body frame 4
Side, avoiding the conditioned soil for meeting partial size from being discharged by discharge port 14 becomes waste material, improves the output of conditioned soil, and reduce
The cost of production of living again.
In the present embodiment, multiple discharge ports 14 are laid along the width direction of the main body frame 4, so as to effectively adapt to
The super partial size conditioned soil that the width direction of main body frame 4 slides.
In the present embodiment, the setting of transmission shaft 7, first, it is in order to which the driving force of driving motor is passed to main body frame 4
It is driven with discharging sieve 1;Second, it is to be driven under the action of eccentric wheel 8 by transmission shaft 7 to be cooperated with eccentric wheel 8
The asymmetric vibration of about 4 main body frame, convenient for the landing of vibration screening and super partial size conditioned soil.
In the present embodiment, the setting of two eccentric wheels 8 is in order to ensure in 4 vibration processes of transmission shaft 7 and main body frame
Alignment, it is ensured that the uniform of sieve mechanism screening that discharge, second are in order to avoid transmission shaft and the radial jump of main body frame 4
It is dynamic big, cause the fracture of drive shafts fracture or main body frame 4 and discharging 1 junction of sieve;
In the present embodiment, the setting of split axle connector flange 10, first, it is to connect driving motor, transmission driving electricity
Maneuver energy;Second, it is to guarantee that split axle connector 9 can guarantee intrinsic shape.
In the present embodiment, the setting of split axle connector 9, first, it is to reduce split axle connector flange 10 and transmission
There is certain damping between axis 7 while frictional force, it can be anti-interference;Second, it is for transmission shaft 7 and the driving motor of being flexible coupling
Output shaft axis, in order to which deviation does not occur for driving motor when guaranteeing that transmission shaft 7 rotates, convenient for the installation of driving motor.
In the present embodiment, the setting of transmission shaft flange 15 is because limiting the transmission shaft 7 for being threaded through main body frame 4
Position, avoid transmission shaft 7 from moving radially and weaken main body frame 4 and discharge sieve 1 vibration, and avoid transmission shaft 7 occur stress
It is unevenly broken, guarantees that whole sieve is firm in the construction process, does not deform.
In the present embodiment, the setting of fixing piece 5 is in order to which the eccentric wheel in one end to transmission shaft 7 is fixed, it is ensured that
Alignment in 4 vibration processes of transmission shaft 7 and main body frame.
In the present embodiment, the setting of high baffle 3 is to avoid out material screen during the discharging sieve 1 vibration
Conditioned soil on net 1 slides out discharging sieve 1, on the one hand reduces environmental pollution, and on the other hand, improves conditioned soil effective quantity.
In the present embodiment, the setting of main body frame heel brace 11 is the height in order to increase the discharging sieve mechanism, is convenient for
The discharging sieve mechanism is mounted on discharge port end, and convenient for installing conditioned soil rewinding in the bottom of the discharging sieve mechanism
Bucket, the setting of pedestal 13, and it is to realize and consolidate to the discharging sieve mechanism for the ease of the fixed installation of the spring legs
Dingan County's dress, and the setting of pedestal 13 and main body frame heel brace 11, are for the ease of the installation of spring 12, convenient for the both ends of spring 12
Receiving fix.
In the present embodiment, the setting of spring 12, first, it is in order to during the discharging sieve 1 carries conditioned soil
There is certain buffering, avoids the gravity of application of the conditioned soil to the discharging sieve 1 larger, cause the damage of the discharging sieve 1
Evil;Second, be in order to vibratory drive mechanism drive the discharging sieve 1 up-down vibration during, reduce the amplitude of vibration,
It avoids the conditioned soil Oscillation Amplitude on the discharging sieve 1 larger and is detached from main body frame 4;Third is in order in vibratory drive
During mechanism drives the discharging sieve 1 to vibrate up and down, the further vibration of discharging sieve 1 can be driven, increases and changes
The movement of good soil screening, improves screening efficiency.
In the present embodiment, the setting of pan feeding sieve 22, and the top cloth at an acute angle of pan feeding sieve 22 and the hack storehouse 21
If each material blanking of auxiliary preparation conditioned soil, on the one hand avoids pulverizer from generating entrance sieve plug-hole accident, needs to hack
Machine carries out power-off maintenance, influences construction efficiency;On the other hand, primary election is carried out to original soil and each material, it is autochthonal improves improvement
Produce efficiency and quality.
In the present embodiment, spraying head type spray head 24 is set, sprays mixing water uniformly, thus with after the stirring in hack storehouse 21
Conditioned soil can uniformly mix.
A kind of conditioned soil production method as shown in Figure 4, comprising the following steps:
Step 1: the broken and sub-material transmission of soil block:
Soil block is put into hack storehouse 21 using loading parts, and enters the process in hack storehouse 21 in soil block by step 101
In, eccentric motor 23 drives pan feeding sieve 22 to vibrate, and is screened and is entered in hack storehouse 21 by pan feeding sieve 22;
Step 102 is crushed the soil block entered in hack storehouse 21 using the pulverizer, obtains hack;
Step 103 is transmitted hack obtained in step 102 using the hack transmission belt 25 in the pulverizer;
Step 2: the transmission of hack:
Hack in step 201, hack transmission belt 25 enters the first tripper 28 and the second tripper 27, into first point
The hack of glassware 28 enters first point of transmission belt 29 by 28 bottom of the first tripper, and the hack into the second tripper 27 passes through
Second tripper, 27 bottom enters second point of transmission belt 26;
Step 202 enters hack and holds feed bin 30 into the hack of first point of transmission belt 29 and second point of transmission belt 26, from
Hack holds the hack that 30 bottom of feed bin comes out and enters first total transmission belt 16;
Step 3: the production and transmission of conditioned soil:
Step 301 is transmitted to a mixing bowl 18 into the hack of first total transmission belt 16, while adding water into a mixing bowl 18
Mud and water, stir evenly, and obtain conditioned soil;
Step 302, the conditioned soil come out from 18 bottom of a mixing bowl enter second total transmission belt 17, and through second total transmission belt
17 are transmitted to the vibration screening mechanism 19;
Step 4: the vibration screening of conditioned soil:
The vibratory drive mechanism drives the discharging sieve mechanism vibrations, makes to enter in the discharging sieve mechanism less
Enter the collection hopper by the discharging sieve mechanism in the conditioned soil of Particle size requirements value, meanwhile, make to enter the discharging
Conditioned soil in conditioned soil in sieve mechanism greater than Particle size requirements value under the action of self-weight can be along the discharging sieve mechanism
Inclined surface slide until be discharged by the discharge port 14, and be collected by the waste tank.
In the present embodiment, the transmittability of first point of transmission belt 29 described in step 201 and second point of transmission belt 26
For 300t/h~600t/h, the transmittability of first total transmission belt 16 and the transmittability of second total transmission belt 17 are
300t/h~600t/h.
In the present embodiment, powder of the granularity no more than 1cm~2cm accounts for 90wt% or more in hack described in step 102;
The mass percent of cement, water and hack is respectively cement 2%~8%, water 15% in a mixing bowl 18 in step 301
~18%, surplus is hack.
In the present embodiment, setting transmittability is not less than 300t/h, be because it is contemplated that loading machine does not stop upper original soil material, in order to
Avoid broken hack grain in pulverizer from pushing the blockings for causing pulverizer more;It in addition is to examine filling roadbed and roadbed
The demand of conditioned soil in basement process pile driving construction;Third, being the quantity in order to reduce pulverizer, save floor occupying area, saving is set
Standby investment and civil engineering costs;Transmittability is set and is not more than 600t/h, is because it is contemplated that broken hack grain holds in pulverizer
Amount is few, and belt sky is caused to pass, and energy consumption is more;It in addition is the quality of finished product after consideration belt transport unevenly causes conditioned soil to produce
It is low;Secondly consider that good overall economic efficiency can be obtained when meeting construction requirement.
In the present embodiment, the mass percent of cement is 2%~8%, be because the mass percent of cement is more than 8%,
Cement and hack chemically react, and generation is hardened, and causes the contracting of conditioned soil big, are easy cracking, reduce construction quality;Water
For the mass percent of mud less than 2%, improvement soil compaction is slightly smaller, cannot bear certain load, be unsatisfactory for construction requirement.
In the present embodiment, grogs of the granularity no more than 1cm~2cm accounts for 90wt% or more in the hack, first, be in order to
Guarantee that soil, water, cement can sufficiently mix uniformly in a mixing bowl;Second, it is to guarantee that conditioned soil finished product material partial size is basic
Meet the design requirement for being not more than 15mm, the partial size quality standard of soil is up to standard before control is mixed and stirred from source, improves conditioned soil
Quality.
In conclusion the configuration of the present invention is simple, design are reasonable and easy to operate, guarantee the continuous and effective of improved production equipment
Ground operation, improves the uniformity of the partial size of finished product conditioned soil, practical.
The above is only presently preferred embodiments of the present invention, is not intended to limit the invention in any way, it is all according to the present invention
Technical spirit any simple modification to the above embodiments, change and equivalent structural changes, still fall within skill of the present invention
In the protection scope of art scheme.