Stainless steel spray tower

Product Model	Stainless steel series (Ø800–Ø3000)
Category	Stainless steel product series
Reference Price	Price on request

Customizable for Working Conditions 14 Technical Parameters

Product Overview

The stainless steel spray tower, also known as stainless steel scrubber, is a vertical wet scrubber made by rolling and welding stainless steel plates, primarily used for treating acidic, alkaline, and high-temperature corrosive exhaust gases. The exhaust gas enters the tower from the bottom inlet, flows through the packing layer to come into reverse contact with the spray absorption liquid for neutralization, and then passes through the stainless steel mesh demister for dehydration before exiting through the top exhaust stack. The absorption liquid falls into the water tank for recirculation and spraying. The equipment features a welded metal structure with mirror or brushed finish, offering superior rigidity and pressure-bearing capacity compared to plastic towers.

The tower body is typically constructed from 304 or 316L stainless steel plates, bent into segments and welded with longitudinal and circumferential seams before being polished as a whole. The welds are smooth, and the inner wall is smooth, making it resistant to scaling and easy to clean. The 304 stainless steel spray tower is suitable for general acid, alkaline, and conventional corrosive conditions, while the 316L, containing molybdenum, offers stronger resistance to chloride pitting corrosion and is ideal for applications with chlorine, salt spray, or more severe corrosion. The tower is equipped with stainless steel circulating water pipes, valves, manholes, sight glasses, ladders, and inspection platforms. The inlet and outlet airflows are connected via flanges.

Compared to PP plastic towers, the stainless steel anti-corrosion spray tower offers higher temperature resistance, does not soften easily at higher inlet temperatures, and exhibits better anti-aging, UV resistance, and mechanical damage resistance. Outdoor and large-diameter tower structures are more stable. Standard tower diameters range from φ800 to φ3000 and can be configured as single towers or multi-stage series arrangements, or as horizontal or non-standard structures. It can be used alone for acid mist washing or as a pre-cooling treatment for high-temperature exhaust gas purification and organic exhaust gas before entering activated carbon or regenerative thermal oxidation.

Working Principle

Contaminated gas enters the tower from the tangential inlet at the bottom, first passing through an evenly distributed space to reduce velocity, and then rising through the packing layer. The recirculation pump delivers the absorption liquid from the bottom tank to the upper spray pipes, where multiple nozzles spray it downward uniformly, forming a continuous liquid film on the packing surface. The rising gas comes into reverse contact with the descending liquid droplets, where gaseous acid and alkaline pollutants are captured and neutralized by the absorption liquid, while dust and soluble substances are carried away by the liquid droplets.

After scrubbing, the gas carries a significant amount of liquid droplets and continues upward into the mesh demister. The liquid droplets collide and coalesce into larger droplets on the mesh before falling back into the tower. The dehydrated gas is then drawn out through the top exhaust stack by a fan. The liquid absorbing pollutants flows to the bottom tank, where chemicals, water, or replacement are added or changed based on pH and concentration. The recirculation pump ensures closed-loop circulation, reducing water and chemical consumption. For applications with more dust or viscous gases, swirl plates can be added or the packing and spray combination adjusted to enhance dust removal and prevent blockages.

Structural Components

The tower, from bottom to top, consists of a tangential inlet, a recirculation water tank, packing support and packing layer, spray section, mesh demister section, and top exhaust stack, with external components including a recirculation pump, water pipes, valves, manholes, sight glasses, ladders, and inspection platforms. The bottom tank stores the absorption liquid and includes interfaces for water replenishment, discharge, overflow, and chemical dosing. The packing layer is supported by grating plates and filled with multi-faceted hollow balls or Raschig rings to increase gas-liquid contact area. The spray section features two or more layers of nozzles, ensuring uniform coverage and minimizing dead zones.

The upper demister section is equipped with a stainless steel mesh demister to remove liquid droplets carried by the outlet gas and protect the downstream fan. Several circular manholes and glass sight glasses are installed along the tower height for observing the spray and packing conditions and for maintenance access. All pipe connections, manholes, and flanges are welded or connected with flanges, ensuring reliable sealing. The entire tower is connected in segments via flanges, facilitating segmented transportation, on-site assembly, and later packing replacement or nozzle maintenance.

Specification Model Table

The table below shows the standard tower diameters for stainless steel spray towers. The tower diameter is selected based on airflow and empty tower velocity, with the spray section, packing layer, and demister section configured in segments according to the tower diameter. Actual plate thickness, material grade, inlet/outlet dimensions, and water tank volume are designed individually based on exhaust composition, temperature, airflow, and site conditions. The table provides conventional structural configurations and dimensions.

Specification Model	Tower Diameter (mm)	Spray Section	Packing Layer	Demister Section	Maintenance Configuration
φ800	800	2/1	Hollow Ball/Raschig Ring	Mesh Demister	Manhole Sight Glass
φ1000	1000	2/1	Hollow Ball/Raschig Ring	Mesh Demister	Manhole Sight Glass
φ1200	1200	2/1	Hollow Ball/Raschig Ring	Mesh Demister	Manhole Sight Glass
φ1500	1500	2/1	Hollow Ball/Raschig Ring	Mesh Demister	Manhole Sight Glass
φ1800	1800	2/1	Hollow Ball/Raschig Ring	Mesh Demister	Manhole Sight Glass
φ2000	2000	2/1	Hollow Ball/Raschig Ring	Mesh Demister	Manhole Sight Glass
φ2200	2200	2/1	Hollow Ball/Raschig Ring	Mesh Demister	Manhole Sight Glass
φ2500	2500	2/1	Hollow Ball/Raschig Ring	Mesh Demister	Manhole Sight Glass
φ2800	2800	2/1	Hollow Ball/Raschig Ring	Mesh Demister	Manhole Sight Glass
φ3000	3000	2/1	Hollow Ball/Raschig Ring	Mesh Demister	Manhole Sight Glass

The tower is connected in segments via flanges, standardly equipped with a recirculation pump, spray pipes, valves, sight glasses, manholes, and water replenishment/discharge interfaces. Dimensions can be designed based on site conditions and airflow.

Product Features

While maintaining wet scrubbing efficiency, the stainless steel spray tower highlights the advantages of metal material in terms of temperature resistance, strength, and durability, primarily demonstrated in the following aspects.

Stainless steel plates are rolled and welded, offering excellent overall rigidity and pressure-bearing capacity, making large-diameter towers less prone to deformation
Superior temperature and fire resistance compared to plastic towers, suitable for higher inlet temperatures and long-term outdoor applications
Polished inner wall is smooth, resistant to scaling and fouling, and easier to clean and replace packing
Two material grades, 304/316L, are available to suit different chloride content and corrosion intensity conditions
Multi-layer spraying combined with packing and mesh demisters ensures thorough gas-liquid contact with minimal liquid carryover at the outlet
Flange segment connections, complete with manholes, sight glasses, ladders, and platforms, facilitate easy maintenance
Closed-loop absorption liquid circulation reduces water and chemical consumption, making it compatible with various exhaust gas treatment systems

Main material	304/316L stainless steel
Tower structure	Vertical cylindrical
Manufacturing Process	Tube welding, overall polishing
Surface Treatment	Mirror or brushed finish
Standard Tower Diameter Range	φ800–φ3000
Inlet method	Bottom tangential airflow
Spray Layer Form	Multi-layer nozzles spray
Type of packing	multi-faceted hollow ball, Raschig ring
Demisting method	Stainless steel wire mesh demister
Recirculation Mode	Pump closed-loop recirculation sprinkling
Pipe connection	Flange connection
Maintenance configuration	Manhole, sight glass, ladder and platform
Object processing	Acid-alkali exhaust gas, acid mist, high-temperature corrosion gas
Installation method	Suitable for indoor and outdoor use

Application Industries

Treatment of acidic and alkaline exhaust gases such as sulfuric acid mist, hydrochloric acid mist, and alkali mist in chemical production
Purification of acid mist and chromium-containing acid mist gases in electroplating and surface treatment acid washing lines
Washing of high-temperature flue gas and acidic/alkaline gases generated in metallurgical and heat treatment processes
Purification of high-temperature acidic/alkaline exhaust air in etching processes of semiconductor and electronics industries
Absorption and treatment of acidic/alkaline exhaust gases in reaction feeding processes of pharmaceutical and food industries
Pre-cooling and dust removal of organic exhaust gases from coating and printing before deep treatment
Centralized washing of exhaust air from laboratories and workshops with fireproof and high-temperature resistance requirements

Typical Process Locations

The stainless steel spray tower is usually connected after the exhaust hood, exhaust branch duct, and main duct. Pollutant-containing gases are first collected via ducts into the tangential inlet at the lower part of the tower, where absorption, washing, and mist removal are completed inside the tower. The purified gas is then drawn away through the top exhaust stack by a corrosion-resistant fan. When the exhaust gas contains adsorbable organic substances, an activated carbon adsorption unit or regenerative thermal oxidation (RTO) can be connected after the tower for deep treatment, with the spray tower responsible for pre-cooling, dust removal, and mist removal. For high-temperature flue gas, the stainless steel tower can be directly placed near the production line to reduce cooling investment for high-temperature gas in plastic pipes and equipment.

During on-site installation, the tower body is connected to upstream and downstream ducts, fans, and circulating water pipes via flanges. The bottom water tank is connected to water replenishment, chemical dosing, and wastewater discharge pipelines, with the circulating water pump installed close to the tower to shorten pipe lengths. If the exhaust gas composition is complex or the concentration is high, a two-stage spray tower in series or segmented washing with alkali or oxidizing solutions can be used. The tower diameter and circulation rate are designed based on the treatment airflow. Xicheng Environmental Protection can provide complete sets of stainless steel spray towers, corrosion-resistant fans, pumps, duct dampers, and downstream activated carbon equipment, along with engineering design, equipment manufacturing, and installation and commissioning services.

The stainless steel spray tower is a vertical wet exhaust gas purification equipment that achieves washing through countercurrent contact between gas and liquid. The exhaust gas enters the tower from the tangential inlet at the bottom, rises through the packing layer, and comes into countercurrent contact with the liquid sprayed by nozzles. Gaseous acid and alkali pollutants are captured by the liquid phase and neutralized, while dust and soluble substances are simultaneously carried away by liquid droplets. After washing, the gas is dehydrated by a mesh demister and discharged through the top exhaust stack via a fan. The absorption liquid falls into the bottom water tank of the tower and is then transported to the top of the tower by a circulation pump for repeated spraying and closed-loop circulation. The entire process ensures thorough gas-liquid contact, enabling continuous treatment of acid and alkali exhaust gas and acid mist, with stable operation and low maintenance requirements.

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.

The main difference lies in the corrosion-resistant level. 304 can meet general acid, alkali, oil mist, and conventional corrosion conditions, with higher usage. 316L adds molybdenum, offering stronger resistance to chloride pitting and crevice corrosion. It is more suitable for chlorine-containing gases, salt spray, coastal environments, and heavier corrosion conditions. When selecting, first clarify the chloride content, acid/alkali types, concentration, and temperature of the exhaust, then determine the grade. Don't just focus on initial cost; a lower grade can lead to early corrosion of the tower, resulting in downtime and replacement costs. For complex compositions or uncertainties, provide test data for technical personnel to judge. Avoid blindly stacking higher grades.

Both rely on packing layers and spray absorption liquid to purify exhaust gas, with the same purification principle but differences in material performance and applicable conditions. PP spray tower is lightweight, easy to process, and has lower cost. It is well-proven for use in ambient temperature dilute acid and alkali conditions, offering good economy. Stainless steel spray tower has higher temperature resistance, greater overall rigidity, and stronger pressure-bearing capacity. It is less prone to softening when exposed to higher inlet gas temperatures. Its performance in fire resistance, anti-aging, and anti-mechanical damage is better, making it more reliable for large diameters and long-term outdoor use. Selection should be based on comprehensive judgment considering exhaust gas temperature, composition, tower diameter, installation location, and budget. Ambient temperature conventional conditions are suitable for PP, while high temperature, fireproof, or large tower diameter conditions are more suitable for stainless steel. Both have their respective applicable ranges.

This is determined by the inherent properties of the metal material itself. The stainless steel exhibits significantly higher heat resistance temperature compared to plastics such as PP. When exposed to higher inlet temperatures, it does not soften, collapse, or deform, maintaining stable structural dimensions. The tower body, welded as an integral unit, possesses strong rigidity and can retain its shape and seal under thermal expansion and contraction as well as long-term high-temperature airflow. Its fire resistance performance also surpasses that of plastic towers, making it suitable for placement near production line heat sources. The specific maximum inlet temperature it can withstand depends on material grade, plate thickness, insulation, and the material of the packing demister. This requires technical personnel to calculate based on actual flue gas temperature, while also considering the temperature resistance of the absorption liquid and internal non-metallic components during selection.

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.

The tower is mainly composed of an air inlet, a water tank, a packing layer, a spray layer, a demister, and an exhaust stack from bottom to top. The lower water tank stores the absorbent, equipped with interfaces for water replenishment, wastewater discharge, overflow, and chemical dosing. The packing layer is filled with multi-faceted hollow balls or Raschig rings to increase gas-liquid contact area. The spray layer is equipped with two or more layers of nozzles to evenly spray the absorbent onto the packing cross-section. The upper mesh demister removes liquid droplets carried by the outlet gas, protecting the downstream fan. The tower is also equipped with a circulating pump, pipes, valves, manholes, sight glasses, ladders, and maintenance platforms. Pipe connections use flanges for convenient transportation, assembly, and maintenance.

In the complete exhaust gas treatment system, it is typically used in conjunction with exhaust hood, duct, damper, corrosion-resistant fan, and exhaust stack. A washing or pre-cooling section can be connected before the tower, and after the tower, activated carbon adsorption unit, dry adsorption unit, or regenerative thermal oxidation (RTO) equipment is installed based on the composition of pollutants. The tower itself is equipped with circulating water pumps, chemical dosing system, and piping valves instruments to ensure continuous supply of absorption liquid. When the system contains both acid mist and organic compounds, a combination of spray tower and activated carbon adsorption is often adopted. First, wash the acid and alkali while cooling and removing dust, then let the downstream equipment adsorb organic compounds, with clear division of labor. Xicheng Environmental Protection can provide complete sets including stainless steel spray tower, corrosion-resistant fan, water pump, duct, damper, and downstream adsorption equipment, taking charge of design, manufacturing, installation, and commissioning.

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