vertical cement kiln

important operation tips for cement vertical mill

Regardless of Rotary kiln operation or grinding, it is necessary to clarify the inherent logical relationship of the system, which requires the operator to have a clear understanding of the characteristics of the system process and equipment.fully understand the dialectical relationship between qualitative and quantitative.

Operator must first learn about the operation of the system.Which equipment has hidden dangers, and how does production influence on cement quality.Read the full analysis report sheet to understand the material's grindability so that targeted control can be achieved.It is necessary to familiarize yourself with the operation interface of the central control and know the field equipment very well, so you should always go to the site to understand the situation of the equipment.Especially when the field device fails, you need to know the cause of the failure and the method to solve the problem.

The proper thickness of the layer and stable layer are basis for stable operation. The material layer is too thick will lead to grinding efficiency reduction, and when pressure difference of the mill reaches the limit, the material will collapse, which will affect main motor and venting system; If material layer is too thin, with driving force of the mill increases, the grinding roller, disc and hydraulic system are damaged.

Excessive vibration of the vertical mill not only directly causes mechanical damage, but also affects production and quality.The factors that cause vibration are: the basis of the mill, the grinding pressure, the thickness of the layer, the air volume and the air temperature, the accumulator pressure, the wear of the roller surface or the grinding disc, and the like.

The influence of materials on vertical mill vibration and the treatment method: it is mainly reflected in the particle size, the wearability and the moisture. In the vertical grinding operation process, to form a stable material layer, it is required that the grinding material has a suitable gradation, and more than 95% of the particle size is less than 3% of the roller diameter. Excessive feed size will result in poor grindability. Since the gap between the bulk materials is not filled with enough fine particulate material, the buffering performance of the material bed is poor, and the impact force when the material is crushed is difficult to absorb, resulting in an increase in vibration. The feed size is too small, especially when the powdery material is long, because the small particle material has small friction and good fluidity. The lack of large materials constitutes a supporting skeleton, and it is difficult to form a stable material bed. The grinding roller can not be effectively pressed and crushed. A large amount of powdery material will increase the dust concentration and ventilation resistance in the airflow. When the limit is reached, the material will collapse and mill vibration will increase.

When the material is too fine, especially when the internal pressure difference of the vertical mill has risen significantly, the feeding should be adjusted in time, grinding pressure and outlet temperature should be reduced and the water spray amount should be increased, powder separator speed should be appropriately reduced. The grinding pressure is increased under the premise of ensuring stable pressure difference and layer thickness.

Material grindability is an important factor affecting the yield. When material grindability deteriorates, grinding cycles number of vertical mill increases significantly. Since most of the material is crushed into fine powder, but it can not meet the requirements of the finished product, it cannot be taken out of the mill by the airflow. As the fine particle material on the grinding disc increases, there will be a situation similar to the fineness of the feed size. Vertical grinding pressure The difference is increased, the ventilation is not smooth, and the external circulation and internal circulation are greatly increased. At this time, the material layer will become extremely unstable, the load of the powder separator will increase, the thickness of the material layer will increase, and the load of the mill will increase. If it is not treated in time, the vibration of the vertical mill will be further aggravated and the main motor will be overcurrent.

The influence of material moisture on the vibration of the mill can not be ignored. If the moisture content of the material is too low, it is difficult for the dried material to reliably form a stable bed on the grinding disc, which inevitably causes the mill to vibrate. When the moisture is too high and the layer on the grinding disc is too low, it is easy to form a cake, which increases the vibration of the mill. For example, in order to meet the material drying requirements, it is necessary to provide a larger air volume and a higher air temperature, which will make the wind speed in the mill higher, and the material that should be settled and dropped is forced to suspend, the external circulation is reduced and the internal circulation is increased. At the same time, due to the high adhesion of the high moisture material, the thickness of the upper layer of the grinding disc is thickened, which increases the chance of collapse and the balance of the bed.

The accumulator mainly provides cushioning for the lifting of the roller set. If the pressure of the accumulator is too high or the nitrogen balloon is broken, the buffering effect will be reduced or even completely lost, resulting in a hard impact of the grinding roller group and the material bed causing severe vibration of the mill.

The vertical grinding water spray system plays an important role in stabilizing the material bed, especially in the case of more powdery materials or low water content in the raw materials, the effect is more obvious, the toughness and rigidity of the material can be increased, and the material grinding is facilitated, protect the roller surface and the grinding disc. The height of the retaining ring determines the maximum thickness of material bed. When the retaining ring is too low, the material layer as the cushion is thinned, the buffering effect is weakened, and the grinding machine will vibrate, and the high ring will cause grinding. Reduced efficiency, reduced production and increased electricity consumption. Excessive wear of the scraper plate, uneven wear of the guide vane and the wind deflector will cause uneven distribution of the air volume in the wind ring and the mill, resulting in different thickness of the material on the grinding disc, causing vibration. Excessive or too low temperature in the mill can lead to damage to the stability of the layer, especially when the temperature is too high, the material on the disc becomes very loose and easy to flow. Not only the material layer is thinned, but also it is not easily crushed by the grinding roller, causing vibration. If the temperature is too low, the material has poor fluidity and is easy to accumulate on the grinding disc, which will result in thickening of the material layer and a decrease in grinding efficiency.

Grinding pressure is the main factor affecting the quality of production. The grinding pressure is adjusted according to the amount of grinding machine feed, material size and easy grinding.In order to maintain a layer of material with a certain thickness on the grinding disc, reduce the vibration of the mill and ensure stable operation, the pressure of the grinding roller must be controlled.When the grinding pressure is increased, the grinding capacity of the mill is increased, but after reaching a certain critical point, it does not change.If the hydraulic cylinder setting pressure is too high, it will only increase the driving force and accelerate the wear of the components, and will not improve the grinding ability.This feature is similar to the working principle of a roller press.However, some manufacturers reduce the maximum value of the grinding pressure when setting the maximum grinding pressure, taking into account the protection equipment.When the grinding pressure is low, the thickness of the layer increases, the current of the main motor increases, the pressure difference within the mill increases, and the vibration of the mill increases.When the grinding pressure is high, the thickness of the layer decreases and the current of the main motor increases.The vibration speed of the mill increases and the component damage is accelerated.So maintaining a proper grinding pressure is a critical operation.

When the temperature of the outlet gas of the mill is too low, the fluidity of the material will be deteriorated, and the qualified finished product cannot be extracted in time. When the pressure difference in the mill is too high, the material will collapse.The method of raising the temperature includes: increasing the suction of the mill, adjusting the fineness by the classifier; increasing the opening of the hot damper to reduce the opening of the circulating wind.These methods are also applicable to other types of raw material mills.However, if the temperature is too high (above 130 C), it will also cause damage to the equipment.The dividing wheel in the lower part of the cyclone will expand and become stuck, and the lubricating grease of the grinding roller will also be cracked.It is also disadvantageous for the tail dust bag.If there is too much powder on the grinding disc, the thickness of the layer will be unstable, so it is necessary to control the outlet temperature of the mill.Each mill has its own adaptation temperature, and the operator must master it during operation.For safety reasons, it is best not to close the inlet damper into the humidification tower during production.

The system air volume must be matched with the feeding amount. The method of adjusting the air volume can generally be controlled by adjusting the power of the mill circulating fan or adjusting the opening degree of the kiln exhaust fan.The wind is going big.When the system air volume is too large, the internal pressure difference decreases, the main motor current decreases; the thickness of the material layer is too low, the vibration value is large, and the sieve residue increases.When the system air volume is too small, the thickness of the material layer increases, the internal pressure difference increases, the main motor current increases, and the vibration of the mill increases.

Feeding is large and satiety is a major cause.However, when the material is poor in wearability, it will also slag.The size of the grinding material is large, the system air volume is insufficient, the grinding pressure is low, the system leaks air, the material layer is unstable, the material ring is low, and the roller surface or the grinding disc wears seriously, which will cause the grinding machine to slag more.

When the raw material is running in the vertical mill, the drying heat source of the material comes from the hot gas at the kiln tail. Therefore, when the vertical mill is operated, the control of the inlet and outlet dampers should be balanced by the kiln mill.When the vertical mill inlet and outlet dampers are balanced, the system's wind will be balanced and will not affect the pressure at the kiln end.

Before the grinding starts, it is necessary to stack enough material on the grinding disc so that when the grinding roller falls and grinds, it will not stop due to high vibration.However, the material layer should not be too high, otherwise the main motor current will be high when the roll is ground, which is unfavorable to the equipment.The air pressure at the nozzle ring before grinding is a key value for the observation level.The situation of each vertical mill is different, and it must be reasonably controlled according to circumstances.Try to increase the ventilation before stopping the machine to make the fine powder into the reservoir as much as possible.If the fine powder is excessively rolled, the vibration of the mill is large.

In recent years, with the improvement of large-scale cloth bag dust collecting technology in China, the long bag dust collector technology used in rotary kiln tail gas treatment of cement rotary kiln with dry process method is increasing da...

Cyclone preheater is one of the core equipment in the new dry cement production process, which is responsible for many functions such as gas-solid dispersion, material heating, gas-solid separation, material transportation and some physical...

cyclone preheater provided for cement plant

The cyclone preheater is the core equipment of the new dry process cement production technology. It uses the suspension preheating method to preheat and partially decompose the raw material to shorten the length of the rotary kiln, and at the same time make the raw material and the hot gas flow in the kiln full. Mixing, improving heat exchange efficiency, thereby achieving the purpose of improving the production efficiency of the entire kiln system and reducing the heat consumption of clinker firing.

Cyclone preheater can make full use of the heat in the kiln, reduce the heat consumption of clinker burning, reduce the floor space of the burning equipment, fully utilize the heat in the kiln, reduce the heat consumption of clinker burning, and reduce the floor space of the burning equipment. AGICO is specialized in designing customers for different geographical and production scales to achieve the desired effect. At present, the five-stage cyclone preheater is the most widely used.

It utilizes the high-temperature airflow accumulated in the kiln and adopts multi-stage circulating suspension preheating method to make the raw material powder and the hot air flow exchange heat well, complete the suspension preheating and partial raw material decomposition, and prepare for the raw material into the kiln calcination.

In recent years, with the improvement of large-scale cloth bag dust collecting technology in China, the long bag dust collector technology used in rotary kiln tail gas treatment of cement rotary kiln with dry process method is increasing da...

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vertical shaft kiln vs rotary kiln

Cement has been an indispensable construction material for a long time now. Kilns to produce cement are almost equally old. Now cement kilns can be divided mainly into 2 types: vertical shaft kiln and rotary kiln. The vertical kiln is the older type and its origin dates back to the 5th century AC. Rotary kilns were first used in 1880. Around the 20th century, they replaced vertical shaft kilns almost everywhere.

A cement kiln is a device that finishes the process of clinker sintering. The kiln heats up the raw materials to a high temperature. As a result, several chemical reactions occur, resulting in the materials fusing together, thus forming the cement. The quality of this cement depends largely upon the features of the kiln, such as the kiln model, kiln speed, kiln diameter, cooling speed, etc.

Let us take a look at how a vertical kiln functions. The kiln is placed upright on the ground, and unlike a rotary kiln, it doesnt rotate. The raw materials flow from the top to the bottom of the kiln while combustion supporting air rises from the bottom to the top. As the materials heat up the air, it would prevent heat loss. Thus, the efficiency of the kiln depends largely upon the temperature profile. Burner types, firing rate, and degree of the draft are some of the factors which affect it.

The function of rotary kiln is to calcine the bulk, the lump, and slurry materials. This kiln consists of a cylindrical vessel which is slightly inclined and rotates. After the materials are poured into the cylinder through an opening in the upper end, the rotation mixes up the materials together and gradually they move towards the lower end of the cylinder. At the lower end, they are stirred up and heated by passing hot gases in the opposite direction. These gases may be produced either in a separate kiln or by a flame inside the same kiln. In case if it is produced inside the kiln, the flame is projected from a burner pipe, using fuels such as pulverised petroleum coke, gas, pulverised coal, and oil.

Apart from cement, rotary kilns are also used to make industrial materials, ferrous metals, refractory materials, etc. Unlike the vertical kiln, heat transfer in a rotary kiln takes place via radiation.

Both types of kilns have their upsides and downsides. While a vertical shaft kiln is cheaper, it also comes with several constraints. You may go for a vertical kiln if you need to produce only a small quantity of cement and the quality doesnt matter much. But a rotary kiln would be better in the long run.

automatic vsk cement plant vertical shaft kiln cement plant | agico

The VSK cement plant is always a good solution for small and medium scale cement manufacturing. It features small floor occupation, low capital investment, and easy installation. AGICO provides vertical shaft kiln cement plants from 50 TPD to 300 TPD. In our plants, we adopt modern vertical shaft kilns, which has a high degree of energy-saving and automation, meanwhile, it can make full use of cheap energy as the main fuel, especially waste gas. Besides, we also equip the plant with other quality cement equipment and provide different production solutions for customers to choose from.

The VSK cement plant manufacturing process is divided into six steps: raw material crushing, raw material proportioning and grinding, raw meal blending and homogenization, clinker calcination, cement grinding, and cement packing. Each step is crucial and indispensable.

Cement clinker features an irregular spherical shape. They should be ground by the cement mill to reach the fineness of the cement product. Adding some mixed materials in this step will help to realize different application requirements.

AGICO Group is an integrative enterprise group. It is a Chinese company that specialized in manufacturing and exporting cement plants and cement equipment, providing the turnkey project from project design, equipment installation and equipment commissioning to equipment maintenance.

china vertical mill, ball mill, rotary kiln manufacturers, suppliers - tongli

Tongli Heavy Machinery Co.,Ltd established in 1958 year, is a member of the China Building Material Machinery Association, a leading enterprise of China Cement Machinery, on the vendor of designated manufacturers for coal industry mechanical and electrical equipment, ISO9001:2008 accredited and accredited as a high-tech & new technology enterprise of Zhejiang Province, national designated"defend the contract heavy credit enterprise", modern enterprise of national top ten cement grinding system of technologies and equipment, at the top of cement equipment manufacturing in Zhejiang Province.

After more than 50 years of continuous development, the company already has a group of experienced technical experts and high-quality management personnel, a first-class science and technology research and development center and engineering service team.

ISO9001:2008 accredited and accredited as a high-tech & new technology enterprise of Zhejiang Province, national designated"defend the contract heavy credit enterprise", modern enterprise of national top ten cement grinding system of technologies and equipment, at the top of cement equipment manufacturing in Zhejiang Province.

At the same time, the company has its own intellectual property rights in the slag vertical mill, raw vertical mill, cement vertical mill, coal vertical mill and rotary kiln, cement mill, wind sweep coal mill, dryer and other cement machinery series host equipment.

During the warranty period, two times a month to guide the user to maintain and maintain the product, and to send a special person for the maintenance and maintenance of the product on the fifteen day before the end of the warranty period.

We are convinced that the customer has given the opportunity for the development of the same force, the interests of the customers in the first place is the purpose of the same force and heavy machine service, so that the customer satisfaction is our eternal pursuit!

clinker from rotary or vertical shaft kiln - page 1 of 1

Dear Sirs,what is the difference between a clinker produced in a rotary kiln and the clinker produced in a vertical shaft kiln?I know that the disadvantages of the VSK kiln are the inclusion of ash in the clinker, the problem with homogeneity of heat distribution, the low production.But I can't understand how much the two clinkers can differ and why.For example: starting from the same raw materials, and supposing a well working VSK and a well working SP Rotary kiln,what could be the difference inthe portland cement (95% clinker 5% gypsum) derived from the two different clinkers in terms of 5 days and 28 days strength?Buying clinker produced in VSK would be a completely wrong move or it can depend from other parameters?Many thanks for Your attention.Davide A.

For example: starting from the same raw materials, and supposing a well working VSK and a well working SP Rotary kiln,what could be the difference inthe portland cement (95% clinker 5% gypsum) derived from the two different clinkers in terms of 5 days and 28 days strength?

Dear Davide,There are a number of reasons why the clinkers might differ, but buying clinker from a VSK would not be a completely wrong move. It would depend on the degree of combination of the clinker, the lime saturation and the silica modulus.There are at least 2 principle reasopns why the clinker from a VSK might have a low lime combination factor: (i) the difficulty of achieving the high temperature required to achieve a high degree of combination, and (ii) the lack of the tumbling action which is achieved in a rotary kiln, which in turn promotes the combination via the sintering reaction.Before making your decision you must know the lime combination of the clinker and be asured that this is consistently achieved.Dr Michael Clark

There are a number of reasons why the clinkers might differ, but buying clinker from a VSK would not be a completely wrong move. It would depend on the degree of combination of the clinker, the lime saturation and the silica modulus.

There are at least 2 principle reasopns why the clinker from a VSK might have a low lime combination factor: (i) the difficulty of achieving the high temperature required to achieve a high degree of combination, and (ii) the lack of the tumbling action which is achieved in a rotary kiln, which in turn promotes the combination via the sintering reaction.

vertical kilns, capacity: 100 tpd and , movers india private limited | id: 2508980455

Good quality limestone with other additives ensures quality production of clinker. Clinker produced in Vertical kiln the has been found to be of excellent quality for producing Portland Cement, Pozzolona Portland Cement and Portland Slag Cement by grinding along with a small quantity of gypsum and other admistures.

Vertical Kiln consists of a round, vertical pipe lined with refractory bricks. A feed arrangemnt at top feeds nodulized raw meal into the kiln at a uniform rate. Burned clinker is extracted at the bottom through a slowly rotating conical grate, which also distributes combustion air into the kiln.

For more than 30 years, we have successfully catered to the diversified demands of various industries with our quality products and services to the Process Industry. We manufacture and supply a wide range of Material Handling Equipment and Conveyors. Our range comprises Industrial Conveyors, Air Lifts & Slides, Industrial Equipment,Bucket Elevators, Belt Conveyors, Apron Feeders, Air Slides, Air Lift, Centrifugal discharge bucket elevator, Belt Feeders, Drag Chain Conveyors, Mechanical Vibro feeders, Pan Conveyors, Rotary Vane Feeders, Mechanical Classifier (Air Separator), Ball Mills and Vertical Shaft Kilns (VSK).

These are known for their optimum performance and are offered in various specifications to cater to diversified requirements of our customers. We have set up a state-of-the-art infrastructure that is equipped with all the requisite facilities and machines that enable us to fabricate an optimum product range. Our every business operation is managed under the careful supervision of our experienced professionals, who work diligently to offer nothing but the best.

vertical shaft kilns - harbisonwalker international

Lime shaft kilns are stationary vertical kilns where the raw limestone enters at the top and gravity flows through three thermally zoned sections known as the preheating, calcining, and cooling zones. The process heats the limestone from ambient temperature to 900C, which is the point where the carbon dioxide is driven off, leaving calcium oxide, also known as quicklime. Modern kilns are typically one of three designs: single shaft, annular, or regenerative. Each respective design is progressively more energy efficient, but all are based on a countercurrent flow of hot air rising from the burners in the calcining zone through the downward material flow.

Our standard linings for vertical shaft kilns consist of wear-resistant hot-face linings and thermally efficient backup linings. This combination provides lime producers with an economical and tough refractory lining that can withstand the thermal and mechanical challenges present in a vertical shaft kiln. Our special magnesite bricks, NARMAG, provide superior strength and abrasion resistance at high temperatures, while our KAST-O-LITE family of insulating materials provides high-temperature insulation to optimize thermal efficiency.

vsk cement plant | vertical shaft kiln cement plant | agico cement

VSK cement plant is short of vertical shaft kiln cement plant, it is mainly applied for small scale cement plants. As the name suggested, the core equipment of the cement plant is vertical shaft kiln. To meet various needs of clients, we supply different sizes of VSK cement plants, such as 50 TPD, 65 TPD, 75 TPD, 100 TPD, 150 TPD, 200 TPD, and 300 TPD.

In general, jaw crusher is suggested in the vertical shaft kiln cement plant, simple structure and reliable operation will greatly improve the outlets of cement crushing, also reduce energy consumption.

The crushed limestone, clay, iron powder, coal, fluorite will be dried and ground in the raw mill, after drying, the friability of cement raw materials will be promoted, which improve the grinding efficiency. The air-swept mill can be considered.

Recently, semi-finishing grinding systems are advanced in cement grinding plant, cement roller press is also essential cement equipment in this system, save 60-70% investment, the power consumption will be reduced a lot. To be specific, clinker, gypsum, and mixing materials will be sent into cement mill in designed proportion, and pass through coarse grinding and finish grinding.

small vertical cement grinding mill / vertical roller mill for raw material

Small Vertical Cement Grinding Mill Energy Saving Low Dust Pollution Vertical Cement Grinding Mill produced by China ZK Corp is is a new type of high efficiency, energy conservation and environmental protection of grinding equipment, widely used in the grinding of raw cement, slag, cement clinker, raw coal and other raw materials. It gathers grinding, drying and powder selecting as a whole, with high grinding efficiency and high drying capacity ( the maximum material moisture can be up to 20% ). The vertical mill adopts dynamic powder selecting device, which comes with high powder-selecting efficiency and convenient adjustment of fineness. China ZK Corp has provided various kinds of large and medium size complete sets of cement production equipments for more than 300 cement customers in domestic market. And engineering for equipment and technology, manufacturing, installation and commissioning as well as the supply of the spare parts and the training service can be offered by China ZK for customers. Vertical Cement mill working process: The material is grinded between rotor and ring as the rotor is rotating. The ground powder will be blown into the classifier; the fine powder will be collected by the collector while the coarse powder will be regrinded to the required size. Our Advantages: 1. High grinding efficiency and low power consumption. 2. Low metal consumption in unit product. 3. Bed grinding with low noise. 4. Negative pressure and low dust pollution. 5. Small floor space, compact layout, system equipment with light weight and low investment for civil construction. Vertical Cement Grinding Mill Model:HRM800,HRM1100,HRM1250,HRM1300 Capacity:Above 100,000 T/year Material:Cement Technical Data Model Grinding plate(mm) output(t/h) output(10kt/a) Main motor power(kW) diameter Pitch blast furnace slag cement Raw meal blast furnace slag cement Raw meal ZKRM08.2 1200 800 1.5~2 3~4 6~8 1.5 3 5.5 55 ZKRM11.2 1500 1100 3~4 5~6 10~12 3 4.5 9 110 ZKRM13.2 1700 1300 8~9 11~13 20~22 6 9.5 17 185 ZKRM15.2 1900 1500 9~10 14~16 26~34 8 12 24 250 ZKRM17.2 2100 1700 12~14 20~23 40~50 10 17 36 355 ZKRM19.2 2300 1900 15~17 24~26 50~60 13 20 43.5 450 ZKRM20.2 2400 2000 18~20 27~30 60~75 15 22.5 55 560 ZKRM22.3 2600 2200 23~25 40~50 85~110 20 35.5 77 710 Working Principle of Vertical Roller Mill When the grinding mill is at work, all the grinding rollers are rolling in the ring, and the materials are driven to the edge of the turnplate by the centrifugal force and fall down into the grinding chambers where the materials are repeatedly pressed, crushed and grinded by the rollers. The high-pressure air blower constantly inhales air within the grinding mill and, in turn, the airflow with crushed materials are brought to the classifier whose high-speed impeller will screen the airflow: the unqualified particle size will fall and return to the mill for being reground while the qualified particle size mixed with air will go into the cyclone powder collector. Most of the qualified powders will fall and exit from the discharging valve at the bottom; a small proportion of the fine powders, with airflow, moves to the dust cleaner, and clings to the surface of the filter bags. At the same time, the fine powders clinging to the surface fall down by the sudden vibration of the filter bags, which is caused by the instantly ejected high-pressure gas controlled by the pulse valve. The materials from the above two lots are sent by the conveyor at the bottom to get finished powders packed. In addition, filtered clean air will be emitted from the air outlet of muffler in the end.

Vertical Cement Grinding Mill produced by China ZK Corp is is a new type of high efficiency, energy conservation and environmental protection of grinding equipment, widely used in the grinding of raw cement, slag, cement clinker, raw coal and other raw materials. It gathers grinding, drying and powder selecting as a whole, with high grinding efficiency and high drying capacity ( the maximum material moisture can be up to 20% ). The vertical mill adopts dynamic powder selecting device, which comes with high powder-selecting efficiency and convenient adjustment of fineness.

China ZK Corp has provided various kinds of large and medium size complete sets of cement production equipments for more than 300 cement customers in domestic market. And engineering for equipment and technology, manufacturing, installation and commissioning as well as the supply of the spare parts and the training service can be offered by China ZK for customers.

The material is grinded between rotor and ring as the rotor is rotating. The ground powder will be blown into the classifier; the fine powder will be collected by the collector while the coarse powder will be regrinded to the required size.

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