FAQ

Polymer Multi-Sphere is not easily broken under normal temperature and proper filling conditions. Breakage usually occurs due to several factors:Dip from manhole height during filling, excessive drop height causing impact; excessively high operating temperature causing material softening and pressure drop; prolonged ultraviolet exposure leading to aging and brittleness; freezing of the filler layer or compression by large crystalline deposits in winter; and insufficient wall thickness or inadequate strength of the sphere itself. Avoid direct introduction of high-temperature flue gas into the packing section; pre-cool when necessary. Control the drop height and spread evenly during filling to reduce impact; select products with sufficient wall thickness and full molding. If broken spheres are detected during operation, shut down the equipment, screen out the fragments, and replenish new spheres to prevent Scrap and Cell Splitter from blocking the downstream grille, spray pipes, and circulation pipelines. Regularly removing and inspecting the filler can determine the degree of aging and crystallization, allowing for batch replacement.

Common practice involves placing the porous plates on plastic support rings or beams welded to the tower wall, with plates overlapping each other and edges secured using pressure strips, clips, or plastic bolts to prevent airflow from lifting or shifting the plates. For sealing requirements, corrosion-resistant sealing strips or soft padding are added between the plates and support rings to prevent gas and fine filter media from short-circuiting through the edges. In adsorption equipment with an upward airflow that impacts the porous plates from below, the installation must be more secure. Pressure frames, pressure strips, or limiters can be added above the plates to constrain both the porous plates and the filter media together. In large-diameter towers, support beams are densely installed in the middle to reduce the suspended span of individual plates, enhance load-bearing capacity, and prevent sagging. The size of the segments must also be considered to allow them to be inserted through manholes and manually handled by a single person, with each segment checked post-installation for proper overlapping and securing.

Whether the valve should open or close during a power outage depends on the site's safety logic and cannot be generalized. In most anti-backflow and maintenance isolation scenarios, the valve is required to automatically close when power fails, using spring-return closing type actuators to cut the pipeline upon power outage, preventing gas crossover and backflow. In cases like emergency ventilation and smoke exhaust, where ventilation must remain unobstructed after a power outage, the valve may need to automatically open during a power failure. When ordering, the fail-safe position must be clearly specified. The spring return direction of the actuator is set at the factory, and open and close types cannot be mixed. Standard non-return actuators maintain their original position after power failure, failing to meet fail-safe requirements. During design, each unit must be marked with the power-off state, and the reset direction and interlock relationships must be clearly stated in the control instructions. Upon arrival, a power-off test must be conducted to confirm that the operation aligns with the design.

The PP formed size head is primarily used for ventilation and exhaust systems. Such pipelines typically operate at low pressure, where socket welding or flange connections can meet the requirements for sealing and strength. If used for liquid pipelines under certain pressure or positive pressure ventilation systems, it is necessary to verify the pressure rating, wall thickness, connection method, and sealing type of the pipe fittings. In such cases, thickened parts may be selected or full-welded reinforcement may be adopted. For liquid pressure pipelines, the weld strength and water hammer effects should also be checked, and selection should not be based directly on the standards for ventilation pipelines. When ordering, provide clear information on working pressure, temperature, medium, and connection dimensions, so that design personnel or manufacturers can select corresponding specifications based on the pressure rating. For applications involving pressure pipelines and safety requirements, it is recommended that professionals perform calculations before determining the model and wall thickness.

The separated liquid must be discharged through a drain pipe equipped with a liquid seal. Common issues include the drain pipe being directly open, causing the fan's negative pressure to draw air from the drain pipe (gas short circuit), insufficient liquid seal height being siphoned off by negative pressure, or the drain pipe being blocked by sludge crystallization. The correct approach is to connect the drain pipe to a U-shaped liquid seal or a water seal tank, ensuring the liquid seal height exceeds the water column height corresponding to the local negative pressure, and regularly draining and clearing blockages. Alternatively, the separated liquid can be redirected back to the tower's bottom sump to form a natural liquid seal. If liquid accumulates at the bottom of the tank, first shut down the equipment to inspect the liquid seal level and pipeline obstructions, correct the erroneous direct discharge, and ensure smooth liquid recirculation while preventing gas bypass.

Before welding, confirm that the flange and duct diameter are matched, and the socket depth is sufficient. Insert the duct into the flange neck socket to the correct position, ensuring the flange surface is perpendicular to the duct axis and free from tilting. First, spot weld symmetrically at several points around the circumference to secure the position. Check the flange perpendicularity and end face flatness, and only then perform full-welding along the neck circumference. The weld bead should be continuous, full, and free from porosity. During welding, take care not to scorch the flange sealing surface. After welding, remove slag and spatter, and wait for complete cooling before installing the gasket. Flange tilting can cause the two flanges to fail to align parallelly, resulting in excessive local gaps, which is a common cause of flange leaks. For batch welding, use fixtures or templates to ensure flange perpendicularity. After welding, inspect each flange individually with a square or template, and correct any non-compliant pieces promptly.

Material selection for flow components and corrosion protection level should be determined based on gas composition, concentration, and temperature. FRP, PP, and corrosion-resistant coatings each have their applicable ranges, and ordinary carbon steel fans cannot be used as substitutes in highly corrosive environments. Impellers require dynamic balancing and corrosion-resistant treatment to prevent uneven corrosion-induced vibration. Motors and electrical components should be placed on the clean side or provided with corrosion-resistant isolation. Fans are often installed after washing equipment to ensure gas purification first. During operation, prevent liquid ingress into the fan to avoid impeller corrosion and vibration; regularly inspect impeller scaling, coating damage, and bearing (motor) condition.

Common causes include actuator torque insufficient or undersized selection, excessive valve disc sealing pressure, valve shaft slipping on the actuator disc, improper stroke limit adjustment, foreign object blocking the valve disc, or valve shaft jamming. First, manually check if the force torque is uniform throughout the valve operation and if there are any sticking points. Then, inspect if the actuator disc mounting screws and valve shaft connection are loose, and reconfirm that the actuator 0-degree and 90-degree limits align with the fully closed and fully open positions of the valve disc. For closed-type valves, ensure the actuator closing torque is sufficient to compress the sealing ring. If the torque is insufficient, replace with a higher torque model.

The resistance of a muffler is related to the flow velocity in the channel, the perforation rate of the inner tube, the spacing between the plates, and the length. The flow area of the muffler should be checked to ensure the velocity inside the cylinder is controlled within the economical range; if necessary, increase the cylinder diameter and enhance the effective flow area. The perforation rate of the inner tube should not be too low, and the ends of the sound-absorbing plates should be streamlined. No debris or dust should accumulate inside the muffler to block it. If an installed muffler has excessive resistance, first check for blockage by water accumulation or deformation of the inner tube. If the design and selection are too small, replace with a model of larger flow area or convert to a multi-channel structure.

The grating plate surface is smooth, and under normal conditions, impurities carried by the spray liquid are not easily adhered. However, after long-term operation, scale in the water, salt crystallization, or filler debris may accumulate on the plate bars, stiffeners, and splicing joints, gradually reducing the effective open area and increasing resistance. During shutdown maintenance, grating plates can be removed piece by piece, cleaned with high-pressure water, or washed with weak acid compatible with the material to remove crystallization. Severely damaged plate bars or stiffeners should be replaced with new plates. To reduce blockage, start from the front end: enhance pre-treatment and dust removal of exhaust gas, regularly replace circulating liquid, and install filters before the water tank and spray pumps to minimize impurities entering the tower. During operation, assess the degree of grating contamination based on changes in the filler layer resistance, and clean the grating during each shutdown for filler maintenance. After cleaning, the plates should be repositioned and secured in their original positions to avoid large gaps caused by misinstallation.

When multiple fume hoods share a fan and main duct, switching or adjusting certain fume hoods can alter the network resistance, causing pressure fluctuations in the main duct. If each fume hood only uses a standard fixed damper, the airflow of the operating fume hoods will fluctuate unpredictably, potentially falling below safe face velocity levels. After installing Venturi variable air volume (VAV) dampers on each fume hood, the dampers automatically adapt to changes in main duct pressure, locking the airflow of each fume hood to the set value without interference. The system only requires a single initial setup during commissioning, ensuring stable operation and reducing the need for repeated airflow balancing adjustments. This is the core value of variable air volume dampers in parallel fume hood systems.

Depends on the pollutants emitted and local environmental protection requirements. When emitting general waste heat and small amounts of harmless gases, dilution and high-altitude discharge through the exhaust stack are typically used. For experiments producing acidic or alkaline mists, organic volatile compounds, toxic or harmful, or odoriferous gases, corresponding treatment equipment such as spray scrubbers or activated carbon adsorption should be connected, and emissions should be discharged after meeting standards. It is common practice to centrally collect exhaust air from multiple fume hoods and then treat it. Whether treatment is required and what process to adopt should be determined based on pollutant types, emission volumes, and environmental impact assessment approval. It cannot be judged solely based on the number of fume hoods.

Salts generated by acid-base neutralization crystallize on the packing surface, combined with dust accumulation, which increases the resistance of the packing layer, reduces airflow, and decreases purification efficiency. Preventive measures include: enhancing dust control in the front-end hood and ductwork, maintaining clean and filtered circulating water, controlling circulating liquid concentration to avoid supersaturated crystallization, and regularly flushing the packing layer with large amounts of water. If blockage occurs, shut down the equipment and enter through the maintenance door to flush the packing with high-pressure water. Soluble crystallization can be cleaned by circulating appropriate dilute acid or dilute alkali (material and waste liquid treatment must be verified), while severely hardened or broken packing should be removed and replaced, along with cleaning accumulated deposits in the grating and water tank.

The actuator life is expressed in terms of full-travel actuation cycles. Under normal use and proper selection, it can meet multi-year frequent start/stop requirements. Actual life is affected by actuation frequency, load torque, environmental corrosion, and power supply quality. Maintenance points: Conduct full-travel open/close tests regularly to check actuation and position signals; inspect the enclosure, junction box seals, and fasteners for corrosion or looseness; manually operate the mechanism periodically to maintain flexibility; keep the damper shaft seat clean to reduce additional load; promptly identify the cause if actuation slows, unusual noises occur, or the motor overheats. Avoid repeatedly powering the actuator while the vane is jammed, as this is the most effective measure to protect the actuator.

Slow operation is often caused by undersized torque selection, dust crystallization and jamming in the valve stem seat, valve disc rubbing against the wall, or excessive sealing pressure. Mid-trip stops are usually due to load exceeding actuator stall protection, limit switch activation too early, or insufficient power supply voltage. First, manually rotate the valve to check the full-range resistance of the air valve, eliminating mechanical jamming and foreign objects, then verify the power supply voltage and torque selection, and inspect the limit position. Lubrication in the valve stem seat of large-diameter air valves can become hardened in low temperatures, increasing resistance. For undersized selection, replace with a higher torque actuator; do not forcibly use it by increasing the protection current.

The pleated muffler exhibits both frictional resistance along the flow path and local resistance at the pleat ends. The magnitude of the resistance is influenced by the channel flow velocity, pleat spacing, pleat head shape, and length. Properly designed mufflers (controlling flow velocity, adopting streamlined pleat heads, ensuring the total cross-sectional flow area between pleats is not less than the duct cross-section) typically have resistance within acceptable ranges. If the pleat spacing is too small, the flow velocity is excessively high, or the muffler is overly long, the resistance will significantly increase, reducing system airflow, increasing fan energy consumption, and generating flow Recycled noise. During design, both noise reduction capacity and pressure drop loss should be calculated.

The flue gas treatment system must operate continuously; if the spray pump stops, the tower will lose absorbent, immediately rendering purification ineffective, and the flue gas may exceed emission standards. Therefore, in cases requiring strict environmental protection or continuous production, it is recommended to configure two pumps (one primary and one backup) and set up fault switching or regular pump rotation to ensure uninterrupted spraying. For intermittent production systems with shutdown and maintenance conditions, only one pump can be equipped with spare parts. Whether to have a backup also depends on emission regulations and production shutdown losses; important emission outlets are recommended to have backups. Backup pump piping must be properly installed to ensure rapid switching in case of a failure.

Activated carbon adsorption transfers pollutants from the gas phase to the solid phase without eliminating them. Saturated activated carbon becomes enriched with organic compounds, classifying it as a solid waste requiring regulated management (typically managed as hazardous waste in most cases). If disposed of indiscriminately, exposed to rain, or stored in high-temperature piles, the adsorbed organic compounds may desorb and release, causing secondary pollution and safety hazards. The correct approach involves collecting saturated carbon in a sealed manner, temporarily storing it in a compliant facility, entrusting qualified units for regeneration or disposal, and implementing the transfer manifest system. The container should also be protected from high temperatures, as activated carbon adsorption of certain substances carries the risk of temperature rise and fire.

Safety Design Requirements VAV systems must enter a safe state during power outages or malfunctions: Valves are typically designed as fail-open or maintained at maximum exhaust capacity (fail-safe type), ensuring fume hoods continue to exhaust at maximum airflow, prioritizing energy waste over the release of hazardous gases; the monitoring panel issues audible and visual alarms to alert personnel for intervention. When selecting, clarify the actuator's de-energized position and alarm logic. Critical laboratories can be equipped with emergency exhaust buttons, which, when pressed, fully open the valves and run the fans at high speed. Regularly conduct drills for fault alarms and emergency operations to prevent fume hoods from continuing gas generation experiments with closed valves.

In organic waste gas treatment systems, spray towers typically serve as front-end pretreatment equipment, first removing dust, particulate matter, and acidic/basic components from the waste gas while also cooling it to prevent these substances from blocking the pores of activated carbon. After pretreatment in the spray tower, the waste gas enters an activated carbon adsorption tower for deep purification, removing VOC organic pollutants. The typical process involves: exhaust gas collection by a hood, pretreatment in a spray tower, entry into an activated carbon adsorption tower, and finally, discharge through a stack via a fan to meet emission standards.