FAQ

In organic waste gas treatment systems, cyclone towers are typically used as front-end pretreatment equipment to first remove paint mist, dust, and particulates from the waste gas, preventing these substances from clogging the downstream activated carbon adsorption layer and extending the service life of the activated carbon. After pretreatment by the cyclone tower, the waste gas enters the activated carbon adsorption box for deep purification to remove VOC organic pollutants. The typical process involves: waste gas collection by hood, followed by dust removal and washing in a PP cyclone tower, then adsorption and purification in an activated carbon adsorption box, and finally discharge through a PP fan via an exhaust stack in compliance with emission standards.

PP Formed Ducts Offer a Wide Variety of Models and Full Specifications, with Two Cross-Sectional Forms: Circular and Square. The Pipe Diameters Cover Multiple Standard Sizes and Can Be Customized Non-Standard According to Customer Requirements. Specific Specifications Need to Be Determined Based on Airflow Processing, Wind Speed Requirements, and On-Site Space. Generally, Main Pipes Have Larger Diameters, While Branch Pipes Have Smaller Diameters. Xicheng Environmental Can Provide a Full Range of Ducts from Standard Small Diameters to Large Diameters, as Well as Matching Components Such as Bends, T-Joints, Conical Ducts, and Air Valves, Offering Complete Supply for Hassle-Free Procurement. If Uncertain About Required Specifications, Technical Personnel Can Calculate the Pipe Diameter Based on Airflow Processing and Design Wind Speed.

The PP elbows, in addition to the standard 90-degree and 45-degree angles, can be customized to other angles based on customer requirements, such as 30 degrees, 60 degrees, etc., as well as special-shaped irregular elbows. Custom elbows are manufactured using plate welding processing methods, allowing for precise design of angles and shapes based on on-site pipeline layouts to meet complex pipeline arrangement needs. The production cycle for custom elbows is relatively longer than that for standard elbows. Specific angles and dimensions must be designed and confirmed by technical personnel based on on-site conditions to ensure compatibility with the pipeline system.

PP processed ducts can be manufactured in various cross-sectional shapes such as square and rectangular, which is one of the advantages of processed ducts over formed ducts. Square ducts are suitable for spaces with limited installation room, such as wall-mounted installations and ceiling placements, allowing for optimal utilization of building space. Square ducts are made by folding and welding PP sheet material, with firm corner welds and flange reinforcement, and can be customized for length and width based on on-site space requirements. In addition to square shapes, custom-made ducts in rectangular, trapezoidal, and other irregular cross-sections, as well as fittings like elbows, tees, and reducers, are also available.

The vertical spray tower features a circular structure, occupying less space and having lower costs, with longer gas-liquid contact time, making it the preferred choice for conventional acid and alkali exhaust gas treatment. The horizontal spray tower is mostly square in structure, with relatively complex manufacturing and higher costs, but has a lower overall height, making it suitable for installation in places with height restrictions such as floors or basements. Both operate on the same purification principle, completing purification through contact between the packing layer and the spray absorption liquid. The specific choice depends on on-site installation conditions and treatment airflow. Under the same treatment airflow, the overall height of the vertical tower is typically higher than that of the horizontal tower.

Xicheng Environmental Protection's products are made of flame-retardant PP material, featuring corrosion resistance, acid and alkali resistance, and other properties. It is equipped with automated equipment such as laser engraving machines, automatic fusion welding and butt welding machines, and injection molding machines, realizing large-scale production.

Product selection requires providing several basic parameters. First is the exhaust gas properties, including pollutant composition, acid-base type, and concentration. The chlorine ion content must also be specified, as it directly determines whether to choose 304 or 316L grade. Second is the treatment airflow, measured in cubic meters per hour. Third are the inlet temperature, humidity, and dust content. Fourth is the on-site installation space, including tower height, footprint, and inlet/outlet port directions. Fifth are the applicable emission standards and material preferences; explosion-proof requirements must also be stated if applicable. With these parameters, the tower diameter, height, grade, packing, and pump can be determined. Standard tower diameters cover φ800 to φ3000.

Acceptance includes aspects of materials, structure, and performance. For materials, verify the V0 flammability rating certificate for the box body, welding rods, and internal components, and take samples for retesting if necessary. For structure, inspect weld quality, drawer quantity and sealing, airflow distribution plate, maintenance door, flange, and legs to confirm full carbon strength. For performance, test equipment resistance, inlet and outlet pollutant concentrations, and purification efficiency under design airflow, check if temperature and pressure differential monitoring are normal. For documentation, verify the activated carbon certificate of conformity, loading quantity, and replacement log requirements. The flammability rating certificate and treatment efficiency test report are important documents for indoor engineering acceptance.

Please provide ventilation system construction drawings (floor plans, sections, and system diagrams), flow rates and cross-sectional dimensions of each pipe section, exhaust gas composition and temperature, flame retardancy level requirements (V0), equipment interface dimensions and orientation, and on-site installation space. If construction drawings are unavailable, provide equipment layout and flow rate parameters, allowing the manufacturer to survey on-site and refine the processing drawings after confirmation before cutting. Additionally, specify plate thickness, flange standards, damper and flexible joint configurations, and whether fire dampers and support brackets are included. The more complete the data, the more accurate the pipe part numbering and on-site assembly, which can reduce rework and on-site pipe modifications.

Please provide the type of acid gas (sulfuric acid, hydrochloric acid, nitric acid, hydrofluoric acid, etc.), concentration, treatment air volume, exhaust gas temperature, humidity, and dust/fume content, the required purification efficiency and emission standards, installation site conditions, and water supply/drainage conditions, as well as the required cabinet material. The type of acid gas determines the adsorbent formulation, concentration and efficiency determine the filter media loading and filter bed thickness, air volume determines the cabinet cross-section, and temperature, humidity, and dust content determine the pre-treatment configuration. Clarifying these parameters is essential to ensure initial purification effectiveness and a reasonable filter media replacement cycle. Do not select based solely on air volume and cabinet size.

After inserting the flexible connector into the duct or equipment interface, secure the end with a flange or clamp that matches the diameter. Position the flange on the straight edge of the connector's light port, adding a sealing pad or applying sealing adhesive if necessary. Tighten the bolts evenly. The two ends of the pipes must be aligned and coaxial to avoid long-term eccentric stress on the flexible connector. The number and width of the flanges should match the diameter. On the negative pressure side, if the flexible connector is not securely fastened, it may draw in air, affecting airflow. On the positive pressure side, it may leak corrosive gases. Therefore, after installation, check for air leaks, collapse, and abnormal vibration at the connection points during fan operation. Re-tighten if loose. Each end of the flexible connector and the equipment should have independent supports to avoid placing weight on the connector. Re-tighten the flanges after a period of operation. Replace aging, torn flexible connectors and failed flanges promptly to ensure long-term sealing of the connection.

Post-shutdown inspection: Check if the valve shaft and shaft seat are dusty or scaled, if the valve disc is stuck by foreign objects or deformed valve body, and if the shaft hole is bonded by incorrect adhesive application. Clean the stuck objects, correct the deformed valve body, apply appropriate lubrication at the shaft seat, and manually operate the valve through its full range to confirm smoothness. If the valve body is subjected to long-term stress deformation due to forced alignment of the pipeline, loosen the pipeline flange to release stress, realign and reinstall the valve before tightening, ensuring the valve body does not bear pipeline-induced stress. For large-diameter valves with high torque requirements, select products equipped with auxiliary mechanisms such as bearings or worm gears. Avoid using force rods for hardening, as this may damage the valve shaft, handle, and connecting rod. After treatment, the valve should rotate smoothly throughout its range without any sticking points. For electric valves, verify that the actuator torque matches the valve specifications. Maintain valve shaft cleanliness and regularly operate the valve to reduce dust accumulation and sticking.

The height of the horizontal tower is low, and multiple maintenance doors can be installed along its side length. Personnel can enter the tower to inspect spray pipes, replace packing, and clean the water tank more conveniently compared to high towers, which is one of the advantages of the horizontal structure. However, when the packing section and number of spray stages inside the tower are numerous, the quantity of internal components is significant, and the positions of maintenance doors must correspond to each functional section, with sufficient space left outside the tower for extracting packing and operating. The daily maintenance content is the same as that of vertical towers: inspecting nozzle blockage and wear, packing scaling, demister fouling, pump and chemical dosing system, water tank drainage, and maintaining the normal pH and liquid level of the circulating liquid.

Two-color PP sheet materials have the same base material and flame retardancy level, with color differences resulting from masterbatch ratio. Their corrosion resistance, heat resistance, and welding performance are essentially consistent, so performance differences should not be a concern when selecting materials based on color. The off-white sheet is a traditional color in the corrosion-resistant equipment industry and is widely used in spray tower, duct, and tank processing, with relatively sufficient market stock. The porcelain white sheet has a neat and bright appearance, commonly used in laboratory equipment, exposed piping, and applications with high requirements for cleanliness. When welding, matching colored electrodes are used for each color to achieve more harmonious weld appearance. Color selection primarily considers on-site appearance coordination, supply habits, and inventory status, without affecting the core performance of the material. If the project has no special color requirements, the commonly used off-white color can be supplied.

Visually, the appearance difference between flame-retardant PP boards and ordinary PP boards is minimal. The reliable way to determine is to check the flame-retardant test report and material certification provided by the manufacturer, which will indicate the flame-retardant grade and testing standards. Alternatively, a simple ignition test can be conducted using edge trim. Flame-retardant boards will self-extinguish after being removed from the heat source, while ordinary PP boards will continue to burn and drip molten material. When the project officially commences, both the flame-retardant test report and material certification should be obtained and retained. Confirmation should be made by combining the edge trim ignition test. Only boards that self-extinguish after being removed from the heat source and have complete documentation may be processed.

Yes. Maintain a certain length of straight pipe section before and after the valve, avoiding immediate proximity to flow disturbance components such as elbows, tees, and diameter reducers, otherwise, airflow turbulence at the vane will affect airflow measurement and regulation stability, and also increase noise. For systems requiring high airflow control accuracy, the valve installation location and straight pipe section length should comply with automatic control design requirements. Additionally, reserve maintenance space near the actuator, use shielded wires for control signal lines and connect them according to polarity, and verify that the signal range matches the actuator settings before power-on.

Required, although it requires no operation, the valve disc is a moving part. Regular inspection during fan maintenance should include: checking if the valve disc lifts and seats freely, if the shaft sleeve has crystallization or jamming, if the seal is aging or contaminated, if the limit stops are loose, and if the valve body welds are intact. Clean dust crystallization promptly, replace the seal when indentation is obvious or hardened and cracked, and inspect the shaft seat as required. For fans not operated for a long time, manually check the valve disc status before startup to prevent blockage and pressure buildup during fan operation.

Yes. A typical automated dosing system consists of a dosing drum, agitator, metering pump, pH online instrument, level gauge, and control cabinet: The pH electrode detects the acidity/alkalinity of the circulating liquid. When the value falls below the set point, the controller activates the metering pump to add chemicals. The pump stops when the set point is reached. A low-level alarm in the drum prompts chemical preparation, and the agitator runs on a timer or during chemical addition. The metering pump allows for adjustable dosing, with dual pumps providing redundancy for enhanced reliability. It is important to note that automated dosing still requires periodic manual chemical preparation, pH electrode calibration, and chemical inventory checks. Automation reduces daily operations but not all maintenance tasks.

For custom-made tees, provide the main pipe diameter or rectangular cross-sectional dimensions, branch pipe diameter or cross-sectional dimensions, the angle and connection direction between the branch pipe and the main pipe, connection methods for all three interfaces, and flange standards. Additionally, specify the plate thickness and flame retardancy requirements. For eccentric tees, indicate whether the branch pipe connects in the direction of airflow or against it, left or right, upper or lower, and whether it includes a flow guide plate. Provide a pipe isometric drawing or mark flow direction on a plan view to clearly express angles and directions, avoiding processing orientation errors. For tees adjacent to equipment or dampers, also provide interface dimensions and flange standards for the adjacent components. Complete parameters and clear drawings enable the manufacturer to accurately perform cutting, determine intersection lines, and design flow guides, ensuring all three interfaces align smoothly upon arrival, reducing on-site modifications and rework.

There are requirements. The elastic modulus of plastic is lower than that of metal, resulting in smaller pipe stiffness and closer spacing of supports compared to steel pipes. The spacing should be smaller for larger diameters and thinner wall plates, and horizontal and vertical pipes have different spacing requirements. Supports should be individually installed at flanges, valves, silencers, and heavier components to bear the weight, without allowing adjacent pipe sections and welds to carry it. Soft padding or dedicated pipe clamps should be added between supports and pipes to prevent wall wear while allowing axial thermal expansion of the pipes. Specific spacing should be determined according to pipe diameter, wall thickness, water filling, and dust accumulation loads by referring to plastic pipe installation regulations, with appropriate densification for large-diameter and high-negative-pressure pipe sections. Support installation should precede pipe connection to avoid welding on suspended pipes, and after operation, regular inspections should be conducted to check for support looseness, pipe deflection, and flange misalignment.