Flame control at different sections is critical during firing in tunnel kilns. Improper heat will compromise product quality and production efficiency. Here, Yonghua Kiln shares practical flame observation skills.Flame Observation and Adjustment Skills for Tunnel KilnsProper flame observation helps promptly tackle problems caused by improper heating.1. Solutions for Excessively High TemperatureCut down coal dosage in raw materials. For gangue bricks, reduce gangue and add more clay.Speed up the feeding pace, though this may cause large black cores inside bricks.Lower exhaust fan output and adjust feeding speed to reduce firing temperature.2. Treatment for Low Temperature During FiringCommon causes include insufficient internal fuel, improper damper operation, or complete consumption of internal fuel in the low-temperature zone.If low temperature results from insufficient air: Raise dampers gradually to increase air volume. Avoid sudden large adjustments which may put out flames.If caused by excessive air: Lower dampers to reduce airflow, or stack bricks at the discharge end to restrict ventilation. Close waste heat dampers in the holding and cooling zone immediately.3. Handling Overheating in the Firing ZoneThe firing zone gets overheated when the brick temperature approaches the upper limit of the sintering range, with the brick color turning from deep yellow to pale yellow. This usually stems from poor flame control or excessive internal coal addition.Countermeasures:Stop adding external coal and monitor flame conditions closely.For localized overheating, blow cold air through observation holes with low-volume fans. Strictly control the proportion of internal coal.For more details, please feel free to contact us.

Various faults may occur to tunnel kilns due to improper operation or other factors during service. Many people are unfamiliar with its maintenance work, which is elaborated as follows.Tunnel kiln maintenance mainly includes four aspects:Repair of internal refractory bricksReplace and rework burnt refractory bricks inside the kiln, such as clay bricks, high-alumina bricks and silica-alumina bricks.Selection and application of bindersInorganic binders are recommended for refractory bricks of tunnel kilns, thanks to their high strength, excellent heat resistance and long service life.Bonding techniquesFor low water-absorbent refractory bricks, apply paste adhesive directly around the bricks before laying. For highly water-absorbent ones, moisten them with Component B prior to gluing.Performance referenceThe cured adhesive features a compressive strength of 90 MPa and tensile strength ranging from 1.8 MPa to 3.3 MPa, well above actual operational requirements. Select proper products according to working conditions.Tunnel kilns are prone to wear and aging under long-term high-temperature operation. Delayed maintenance will lead to severe equipment damage and potential accidents. Please attach great importance to regular maintenance.

To ensure operational safety, explosion prevention is essential for tunnel kilns. However, many operators lack relevant practical knowledge. Below, Yonghua Machinery gives a brief explanation.During the construction of mobile tunnel kilns, install a complete explosion-proof system consisting of control devices and testing instruments. The system will send out alarms once abnormalities are detected to remind staff to take safety precautions.Before startup, fully commission alarm devices and complete all explosion-proof preparations. Keep a close watch on changes in gas supply, pressure and air temperature during operation, and handle any faults promptly.For maintenance and hot work, cut off the gas supply when servicing gas equipment and pipelines. Conduct air sampling and carbon monoxide testing to prevent the formation of explosive gas mixtures.That’s all about explosion prevention for tunnel kilns. For more information, please visit the official website of Yonghua Machinery.

When constructing a mobile tunnel kiln, numerous details from design, material selection to construction are easily overlooked. To ensure proper kiln building, Yonghua Kiln introduces four essential points.Selection of kiln structure and control system. Fully automatic computer-controlled kilns are widely adopted nowadays to improve production efficiency.Determination of kiln capacity. On the premise of guaranteed output and continuous production, confirm the kiln capacity according to production volume, product type and the size of each kiln car.Specification of kiln cars. The standard width of kiln cars ranges from 0.9m to 1.1m. An excessively wide kiln will lead to severe temperature difference between the interior and exterior.Selection of refractory materials. Refractories vary greatly in refractoriness and thermal insulation performance. Choose suitable materials based on the actual firing temperature.There are more considerations for mobile tunnel kiln construction. Feel free to contact us for further consultation.

Yonghua Kiln reminds you that proper maintenance of mobile tunnel kilns directly affects product quality, output and service life. Here are three key maintenance methods.Manage water accumulation and drainage around the kiln. Excessive surface and underground water will soften the foundation, reduce ground bearing capacity, and cause structural deformation and cracks of the kiln body.The high-temperature refractory bricks are prone to spalling and falling off. Apply protective coatings on high-temperature surfaces to isolate them from direct flame contact and extend the kiln's service life.Metal pipes inside the kiln are vulnerable to oxidation and corrosion under high temperature and humidity. Conduct regular inspections and take anti-corrosion measures in advance to ensure stable operation.The above three effective maintenance methods help keep the kiln in good condition and prolong its service life.