The two-stage air lock valve is the core air-locking and discharging equipment specially designed for the bottom discharging system of vertical lime kilns. It is widely matched with disc ash dischargers and kiln bottom aggregate bins, exclusively applicable to all types and capacities of vertical lime kilns. Adopting a series-connected double-flap sealing structure, the equipment realizes continuous ash discharging and full-process air locking through the alternate opening and closing of the upper and lower valve flaps. It effectively solves the common problems of single-layer discharge valves such as air leakage, unstable kiln internal air pressure and unbalanced calcination working conditions. It stabilizes the combustion-supporting air supply inside the vertical kiln, improves lime activity, reduces coal and power consumption, and fully adapts to vertical lime kiln production lines with a daily output ranging from 50t to 800t.

The valve body is divided into three independent sealed cavities: upper valve bin, intermediate buffer bin and lower valve bin. It operates automatically and cyclically through a pneumatic or electric control system:

First, the upper flap opens, and the calcined lime blocks in the kiln fall into the intermediate buffer bin, while the lower flap remains fully closed to isolate external cold air backflow. After the upper flap is completely closed and sealed, the lower flap opens to discharge the lime materials in the buffer bin to the subsequent conveying equipment. Once the discharging process is finished, the lower flap closes automatically to complete a single working cycle.

During the whole operation process, at least one flap is kept in a closed sealing state at all times, ensuring continuous airtightness at the kiln bottom, no leakage of combustion-supporting air and no inhalation of cold air, so as to maintain long-term stable thermal parameters of vertical kiln calcination.

Valve Body Assembly: Adopts thickened carbon steel welded structure with built-in wear-resistant lining plates and reserved maintenance manholes, facilitating regular ash cleaning and sealing part replacement.

Two-Stage Flap Sealing Mechanism: Equipped with heavy-duty upper and lower flaps. The edge of the flaps is fitted with high-temperature and wear-resistant rubber/ceramic sealing strips to resist high-temperature scouring and abrasion of lime materials.

Driving Unit: Two optional driving modes including pneumatic cylinder drive and electric reducer drive, adapting to different air source and power supply conditions of production sites.

Transmission and Reset Assembly: Consists of crank connecting rod, automatic reset counterweight, wear-resistant valve shaft and external lubricating grease nipples for convenient daily maintenance.

Electric Control System: Equipped with proximity switches and timing control boxes to accurately control the opening and closing sequence of the upper and lower flaps, ensuring standardized and automatic operation.

Excellent Air Locking Performance with Uninterrupted Discharging

Different from traditional single-layer discharge valves that require air shutdown during discharging, the two-stage alternate sealing structure realizes zero air leakage during continuous discharging. It stabilizes the internal air pressure of the kiln, avoids heat loss and lime under-burning or over-burning caused by air leakage, saves 8%–15% of coal consumption and more than 10% of fan power consumption comprehensively.

Complete Product Particle Size with Low Crushing Rate

The flexible flap discharging mode causes no extrusion and crushing of lime materials, effectively maintaining the integrity of finished lime blocks, reducing powder generation and improving product economic value.

High Temperature and Wear Resistance for Harsh Working Conditions

The internal lining of the valve body is made of high-strength wear-resistant steel plates. The sealing parts can withstand long-term scouring of high-temperature lime materials below 300℃, with stable performance and long service life.

Stable Operation and Low Maintenance Cost

All transmission parts are equipped with external lubrication points. The reserved maintenance door enables rapid cleaning and parts replacement. The equipment has a low failure rate and no frequent shutdown maintenance is required.

Full Specification Adaptability

It is compatible with small, medium and large vertical lime kilns (daily output 50t–800t), including semi-mechanized and fully mechanized vertical kilns. Customized square or rectangular feed inlets are available.

Environmentally Friendly and Dust-Free

The fully closed discharging structure prevents dust overflow. It can match with supporting dust removal systems to meet industrial environmental protection emission standards.

Applicable Equipment: All specifications of mechanized and semi-mechanized vertical lime kiln bottom discharging systems

Processed Materials: Calcined quicklime blocks and lime fragments

Material Temperature: ≤300℃

Working Air Pressure: Universal for slight positive pressure and slight negative pressure kiln working conditions

Driving Mode: Pneumatic cylinder type / Electric reducer type

Supporting Equipment: Disc ash discharger, aggregate hopper, belt conveyor, scraper conveyor

Model	Feed Inlet Size (mm)	Adaptable Kiln Daily Output (t/d)	Max Discharging Capacity (t/h)	Driving Mode	Motor Power (Electric Type)	Cylinder Specification (Pneumatic Type)	Valve Body Thickness (mm)	Working Temperature	Flange Bolt Hole	Total Weight (kg)
JY100	300×300	50–100	8–12	Electric / Pneumatic	0.75kW	Φ100	10	≤300℃	8×Φ16	320
JY200	400×400	100–200	15–22	Electric / Pneumatic	1.1kW	Φ125	12	≤300℃	12×Φ18	450
JY300	500×500	200–400	25–38	Electric / Pneumatic	1.5kW	Φ125	12	≤300℃	12×Φ18	630
JY500	600×600	400–600	40–55	Electric / Pneumatic	2.2kW	Φ160	14	≤300℃	16×Φ20	880
LSXF-800	800×800	600–800	60–80	Electric / Pneumatic	3.0kW	Φ160	14	≤300℃	16×Φ20	1260

Installation Position: Fixed vertically by flange directly below the discharge port of the vertical kiln bottom disc ash discharger to ensure natural and smooth material falling.

Power and Air Source Configuration: The pneumatic type requires clean compressed air of 0.4–0.6MPa; the electric type is connected with 380V industrial power supply and matched with a special timing control cabinet.

Timing Adjustment: Adjust the opening and closing interval of the valve flaps according to the actual discharging speed of the vertical kiln to avoid material blockage in the buffer bin or air leakage caused by empty bin.

Daily Maintenance: Check the wear of sealing strips and valve shaft lubrication every shift; open the maintenance door monthly to clean the adhered lime agglomerates inside the bin.

Customized Material Options: The standard valve body is made of Q235 carbon steel; 304 stainless steel lining and ceramic sealed flaps can be customized for high-wear working conditions.

The two-stage air lock valve is an essential energy-saving and efficiency-improving supporting equipment for vertical lime kilns. It solves the long-term pain points of traditional discharging equipment such as serious air leakage, unstable kiln working conditions and high energy consumption. With full-specification compatibility, stable operation, high automation and low operation and maintenance costs, it is the preferred air-locking discharging equipment for new vertical lime kiln projects and old kiln energy-saving renovation projects.