FAQ

Huizhou Xicheng Environmental Protection Technology Co., Ltd.'s PP fire-resistant spray tower has low maintenance costs, primarily involving the regular replacement of nozzles, pumps, and filter materials. The equipment service life can reach 5-8 years, as the PP material has strong anti-aging properties, and the structural design is rational, reducing failure rates and helping customers lower long-term operating costs. As a professional environmental protection equipment manufacturer, Xicheng Environmental holds over 100 national patents and ISO9001 certification, and has industry-university-research cooperation with universities such as Xi'an Jiaotong University and Tongji University. We can provide customers with full-process services, including solution design, equipment manufacturing, installation, and commissioning. For technical consulting, please call 18038067815, and our professional team will provide customized solutions for you.

Huizhou Xicheng Environmental Protection Technology Co., Ltd. produces PP Flame-Retardant Spray Towers, which are suitable for treating industrial exhaust gases such as acidic, organic acid, and inorganic acid gases. They are particularly ideal for front-end exhaust gas treatment in industries such as chemical, electroplating, and painting. Made with flame-retardant PP material, the towers exhibit strong corrosion resistance and can effectively handle high-concentration, high-temperature exhaust gases, ensuring stable equipment operation. As a professional manufacturer of environmental protection equipment, Xicheng Environmental holds over 100 national patents and ISO9001 certification. Collaborating with universities like Xi'an Jiaotong University and Tongji University in industry-academia-research partnerships, we provide comprehensive services covering solution design, equipment manufacturing, installation, and commissioning. For technical consulting, please call 18038067815. Our professional team will offer customized solutions to meet your needs.

Xicheng Environmental Protection is a professional manufacturer of environmental protection equipment, mainly dealing in environmental products such as permanent magnet energy-saving fans, waste gas treatment equipment (PP spray towers, activated carbon adsorption towers, cyclone towers), and pipe fittings (PP/PVC pipes, elbows, tees, flanges).

It primarily handles acidic and alkaline waste gases such as sulfuric acid mist, hydrochloric acid mist, nitric acid mist, alkaline mist, and chromic acid mist. It can also wash some organic gases soluble in the absorption liquid, as well as dust-containing and oil mist-containing gases. Compared to plastic towers, it is more suitable for corrosive gases with higher inlet temperatures or those carrying heat, and is commonly used for high-temperature exhaust gas purification. When there is more dust or oil mist, swirl plates can be added or the packing can be adjusted to enhance dust removal and anti-blocking. The absorption liquid is prepared according to the pollutant composition: acidic gases use alkaline solutions, and alkaline gases use acidic solutions. Concentration and circulation rate are designed based on airflow and concentration. In high-concentration conditions, multi-stage in series treatment can be adopted.

Equipment installed indoors, on equipment floors, in basements, or in areas with high fire protection requirements, and handling organic exhaust gas, should prioritize the selection of V0 PPs flame-retardant carbon boxes, paired with V0 flame-retardant ductwork and dampers to meet building fire protection and safety requirements. When equipment is independently installed outdoors, with sufficient fire separation distance from the factory, and in areas with lower fire protection requirements, standard PPs or other material carbon boxes can be selected to control costs. Regardless of the material, safety measures for activated carbon adsorption processes cannot be omitted. Specific configurations should be based on building fire protection design and local review requirements, with V0 configurations recommended for critical locations.

When standard specifications cannot meet on-site requirements, non-standard processing is required, such as: complex indoor pipeline routing, requiring a large number of custom-shaped elbows and tees; special equipment interface dimensions and orientations, needing transition pieces like round-to-square and square-to-round; custom rectangular sections constrained by ceiling height and structural limitations; matching with V0 flame-retardant equipment requiring unified material and flange specifications; retrofitting projects with limited space requiring on-site measurement and piping installation. Non-standard processing is manufactured section by section according to drawings, ensuring precise installation, but the processing cycle is longer than standard pipes. Drawings or on-site measurements should be provided in advance.

The replacement cycle depends on the type of acid gas, concentration, airflow, filter loading, and actual operating time. It can be theoretically estimated based on the adsorbent capacity and acid gas generation rate. During operation, the replacement point is determined by monitoring the outlet acid gas concentration. The filter media should be replaced when the outlet concentration approaches the emission limit (penetration point); it should also be replaced or treated if the pressure drop across the filter bed significantly increases, the filter media becomes clogged with dust, or it becomes hardened. In design, the filter media quantity is determined to ensure purification efficiency and a reasonable replacement cycle (typically lasting several months). During operation, establishing pressure drop and concentration records is more scientific than replacing based on fixed days, avoiding waste from premature replacement or exceeding limits due to delayed replacement.

Soft joints collapse under suction, typically due to insufficient stiffness in the corrugated section or excessively thin pipe walls, which cannot withstand the negative pressure at the fan inlet. During high airflow concentration, the pipe walls inwardly collapse, resulting in increased resistance and noise at a mild level, or blockage of the airflow path and insufficient airflow at a severe level. It is recommended to select soft joints with reinforced corrugations matched to the fan's negative pressure, avoiding excessively thin or long products. For large-diameter and high-negative-pressure fan inlets, it is particularly important to verify the pressure-bearing capacity of the soft joint. If necessary, support rings should be installed inside the soft joint or its length should be shortened. During installation, the soft joint should not be stretched to its limit, nor twisted or eccentric, maintaining a naturally slightly loose state. Collapse may also be caused by excessive airflow at the fan inlet, incorrect valve closure, or filter blockage leading to elevated negative pressure. The system conditions should be simultaneously checked. If collapse is detected, replace the soft joint with sufficient pressure-bearing capacity and eliminate abnormal negative pressure to prevent repeated damage.

Not suitable. PVC has a relatively low heat resistance temperature. Long-term passage of high-temperature gas will cause the valve body and valve disc to soften and deform, leading to valve disc jamming, poor closure, and even valve body damage, affecting system operation. High-temperature exhaust should use PP, fiberglass, or metal dampers. Pre-cooling sections such as spray cooling should be installed before the exhaust enters plastic equipment to reduce the temperature to within the material's allowable range. When selecting, both the normal continuous temperature of the exhaust and the potential peak temperature must be clearly provided, leaving a safety margin, and materials should not be selected solely based on normal temperature conditions. Even short-term high temperatures or frequent temperature fluctuations will accelerate the aging and deformation of PVC valves. For conditions with unclear temperature boundaries, it is advisable to directly select a material with higher temperature resistance to avoid the valve becoming the temperature weak link in the system. Replacing the valve after commissioning will affect production.

The horizontal tower primarily features cross-flow contact. Its single-stage mass transfer driving force is generally inferior to that of vertical counter-current towers, but through multiple-stage spraying, multi-section packing, lower internal tower velocity, and sufficient gas-liquid contact time, horizontal towers can still achieve the designed purification efficiency. Horizontally arranged washing equipment is well-established in engineering applications. Design considerations should determine the number of spraying stages, packing length, and liquid-to-gas ratio based on exhaust gas concentration and efficiency requirements, rather than simply scaling down from vertical towers. With proper design and maintenance, horizontal towers can reliably meet emission standards for low-concentration, high-volume acid and alkali exhaust gas treatment in indoor environments.

The PPs sheets are joined using hot melt welding, employing flame-retardant welding rods of the same material as the base material. The welding rod and the joint of the sheets are simultaneously heated to a molten state by a hot air gun and then pressed together to fuse. After cooling, a continuous and dense weld is formed. The welding quality depends on temperature control, welding rod selection, groove preparation, and welder proficiency. Properly executed welds can achieve strengths of over 80% of the base material. Thick plates and load-bearing welds should be grooved and welded in multiple passes. Visual and leakage inspections should be conducted after welding. After welding, the weld and the base material have the same material composition, retaining the same corrosion resistance and flame-retardant properties, without the rusting issues associated with metal welding. As long as the welding is performed according to the process and proper inspections are conducted, the sealing and service life of the weld area can match that of the base material.

From the perspective of welding strength and corrosion resistance, porcelain white welding electrodes of the same material can be used to weld beige panels. Both the electrode and the base material are polypropylene, and after hot melt fusion, the mechanical properties and corrosion resistance of the weld are unaffected. However, when porcelain white welding electrodes are applied to beige panels, they form distinct light-colored welds with a strong color contrast, affecting the overall consistency of the equipment's appearance. For equipment with high aesthetic requirements and exposed welds, it is recommended to use matching beige flame-retardant welding electrodes, as the weld color closely matches the base material, resulting in a harmonious and aesthetically pleasing finish. If welding is required in internal or concealed areas of the equipment, color difference is not an issue, and porcelain white electrodes can also be used. When purchasing, ensure to match the welding electrodes with the panel color and leave additional allowance for re-welding to avoid noticeable color differences later.

Both are standard analog signals. The 0-10V voltage signal features simple wiring and low cost, making it suitable for applications where the valve and controller are relatively close together and the electromagnetic environment is favorable. The 4-20mA current signal offers strong anti-interference capabilities, long transmission distance, and zero current during a break for easy fault detection, making it ideal for long-distance wiring and industrial environments with strong interference. When selecting, it must match the controller's output module. It is recommended to standardize the format in the same project. The signal type and valve position action direction (positive or negative action) can be set on the actuator.

No. The function of PPs fire-resistant check valves is self-extinguishing of materials upon separation from the fire source and automatic prevention of air flow reversal. They do not possess fire protection features such as temperature-induced melting, electric closure, or fire resistance integrity. When air ducts pass through fire-rated compartments, floors, or server rooms, they must be installed in accordance with fire protection codes using certified fire-rated dampers or smoke exhaust dampers. The fire-resistant check valves are installed in indoor pipe sections either before or after the fire dampers, each serving its specific purpose. Fire-rated dampers must be installed where air ducts penetrate fire-rated compartments or floors. No plastic valves can substitute for fire dampers. After installation, fire inspection and acceptance must be conducted in accordance with regulations.

PP exhibits excellent corrosion resistance to alkaline solutions such as sodium hydroxide and can be safely stored within ambient concentration ranges. Weld joints using the same material electrode will not be corroded by alkaline solutions. Attention should be paid to the exothermic effect of strong alkali dilution; when preparing, follow the operating procedures by adding water first, then slowly adding the chemical while stirring to avoid local overheating. The combination of concentrated alkali and high temperature will accelerate material aging, so design temperature should have a safety margin. For other chemicals such as strong acids, oxidizers, and organic solvents, verify the compatibility of PP separately – do not generalize that PP is resistant to all chemicals.

Three interfaces with the same size are equal-diameter tees, used for branching or merging of pipelines with the same diameter; when the main pipe diameter remains unchanged and the branch pipe diameter decreases, it is a reducing tee, used for diverting small branch pipes from a large main pipe. In ventilation systems, the airflow at each collection point is typically much smaller than the main pipe airflow, and the branch pipe diameter is also smaller, so the vast majority of branching uses reducing tees. Reducing tees maintain stable main pipe velocity while ensuring the branch pipe velocity meets gas transport requirements, making them a frequently used form in engineering. Equal-diameter tees are mostly used for splitting pipelines with the same diameter between main pipes, or for connecting equipment interfaces with the same diameter. When selecting, judge based on the actual diameters of the three interfaces. The reduction transition of the branch pipe should be smooth to avoid additional resistance caused by sudden reduction; if necessary, a reducing adapter should be installed separately after the tee.

The longitudinal seams of PPs ducts and circumferential seams of fittings in standardized welding are continuous and full. The welding electrodes melt seamlessly with the base material, ensuring no air leakage under normal use. Air leakage primarily occurs at weld defects such as incomplete fusion, porosity, or lack of penetration, or at worn-out or failed flange gaskets. During machining, bevels should be opened according to plate thickness and pressure, welding temperature and gun travel speed should be controlled, and thick plates should be welded in multiple passes. After welding, visual inspections of the ducts are required, and for high-purity systems, section-wise air leakage tests can be conducted. During installation, flange bolts should be tightened diagonally and evenly, with gaskets centered and intact. Butt welds should be fully welded along the circumference to keep the system's air leakage rate within the design range. If leaks are detected, mark their locations, perform patch welding or replace gaskets after pressure relief. Negative pressure duct sections, in particular, must ensure longitudinal seam and flange sealing.

When ordering, clearly specify the requirement for flame-retardant PPs material and agree on the flame-retardant grade. Request the manufacturer to provide the flammability test report for the corresponding batch of sheets. If necessary, conduct oxygen index or vertical burning tests according to standards. On-site verification can be performed through sheet markings and quality certificates. Flame-retardant PPs sheets and ordinary PP sheets have similar appearances, making them difficult to distinguish by the naked eye. Relying on methods like burning smell for identification is unreliable. For critical projects, clearly state material standards and acceptance criteria in the contract to prevent the substitution of ordinary PP for flame-retardant sheets.

The distinguishing basis is the plane where the airflow changes direction after installation. Horizontal elbows cause the duct to turn left or right within a horizontal plane, with the side plates of the elbows placed horizontally; vertical elbows cause the duct to bend up or down, with the duct turning within a vertical plane. Although their processing structures are similar, their installation directions and side plate stress differ, making them not easily interchangeable. When ordering, it is essential to specify on the drawing whether it is a horizontal or vertical elbow, left or right turn, upward or downward bend, as well as the elbow angle to avoid directional errors that could lead to on-site installation issues. For ducts installed against walls or beams, the relationship between the elbows and the wall or beam bottom must also be noted. Elbows with flow guides also require the indication of the turning plane. Before installation, verify the elbow direction against the drawing and on-site layout to ensure the curvature center and airflow direction align before positioning, which can prevent the need for a full rework.

Buckling or concaving of the panel surface indicates insufficient panel reinforcement. Rectangular large panels will warp under differential internal and external pressure. Reinforcing bars or frames must be installed based on the magnitude of negative pressure and the panel span to divide the large panels into multiple smaller cells, reducing unsupported spans. Square tubes showing obvious deformation should be taken out of service. Additional reinforcement and denser support brackets must be added externally, and thicker materials or smaller cross-sections may need to be replaced if necessary. During the design phase, panel thickness and reinforcing bar spacing must be verified against the full pressure of the fan. It is crucial to address buckling or suction collapse during installation rather than waiting for post-installation remediation, especially for high-negative-pressure systems. The specifications, spacing, and welding methods of reinforcing bars must match the panel thickness and cross-section. For pipe sections with high negative pressure, reinforcement should also be added near the flanges. After commissioning, focus on observing the panel for breathing fluctuations and abnormal noises. Stop the machine and address deformation promptly upon detection.