Comparison of Traditional Grinding Equipment Pain Points: Why Dedicated Dry Desulfurization Grinding Mills Fit the SDS Process

I. Introduction: Many desulfurization projects exceed standards because the problem lies in the front-end pulverizing stage

As environmental supervision continues to tighten, the SDS sodium bicarbonate dry desulfurization technology, with its advantages of lightweight, zero wastewater, and simple operation and maintenance, has been widely applied to industrial kiln flue gas retrofit projects. However, many projects have exposed many thorny problems after being put into operation: large fluctuation in desulfurization efficiency, SO2 emissions near the limit, increasing sodium bicarbonate consumables, frequent blockage of injection pipes, and frequent mill wear and repair. Excluding downstream factors such as flue injection process and air volume ratio, more than 80% of the problems stem from wrong selection of desulfurizer grinding equipment.

Many contractors, to compress initial equipment investment, use ordinary hammer mills, old Raymond mills, and small ball mills to replace the dedicated dry desulfurization air classifying grinding mill, seemingly saving money upfront but generating high hidden costs later. This article compares the fatal shortcomings of traditional grinding equipment in SDS dry desulfurization and explains the irreplaceability of the dedicated dry desulfurization grinding mill.

II. Core Pain Points of Three Types of Traditional Grinding Equipment Used for Sodium Bicarbonate Dry Desulfurization

(1) Ordinary Hammer Mill: No Classification System, Completely Out of Control Particle Size

Conventional open hammer mills rely only on screens to control discharge particle size, with four major flaws:

Severe bipolar particle size: part of the powder is over-pulverized into ultrafine dust, while another part of coarse particles directly passes through the screen, with D90 often exceeding 50 μm. Coarse sodium bicarbonate entering the flue cannot fully decompose and react, with effective reagent utilization below 60%, and consumable consumption directly increasing by more than 35%. Screen easily damaged and blocked: sodium bicarbonate slightly absorbing moisture easily sticks to the screen, requiring frequent disassembly and cleaning, with long downtime affecting continuous boiler production. No negative-pressure enclosed structure: large dust flies during pulverizing, workshop dust exceeds standards, failing environmental management requirements. Cannot adjust fineness online: different aperture screens must be changed to change particle size, cumbersome debugging, unable to dynamically adjust powder activity according to flue gas sulfur content.

(2) Raymond Mill: Suitable for Limestone Dry Powder, Not Suitable for Brittle Sodium Bicarbonate Material

The Raymond mill was originally designed for dry pulverizing hard ores such as limestone and calcite. Its drawbacks for sodium bicarbonate grinding are obvious:

The grinding principle is roller pressing and grinding. Sodium bicarbonate, with its soft texture, is easily rolled into flake caking, worsening powder flowability and easily blocking pneumatic conveying pipes. The equipment is bulky and heavy, difficult to place in small boiler rooms and environmental machine rooms, with large civil foundation investment. The overall power consumption is high, with large electricity cost per unit output, and high long-term operating costs. The internal air duct is complex, sodium bicarbonate residue is difficult to clean, easily absorbs moisture and deteriorates during long shutdown, breeding caking and blocking internal pipes.

(3) Horizontal Ball Mill: High Energy Consumption, Large Footprint, Completely Unsuitable for Dry Process

Ball mills are mostly used for limestone wet slurry making. Forcibly dry grinding sodium bicarbonate has prominent defects:

Grinding relies on steel ball impact and friction, with irregular powder particle morphology and small specific surface area, and extremely low desulfurization reaction activity. The whole machine is heavy and occupies a large area, with many supporting auxiliary equipment, and the infrastructure and installation costs of the whole system double. The no-load energy loss is high; grinding one ton of sodium bicarbonate consumes 1.8 times the electricity of the dedicated classifying mill, with serious energy waste. The discharge has no refining classification, mixing coarse and fine materials, requiring additional external classification equipment, with long pipelines, and sodium bicarbonate agglomerates by moisture during transfer, increasing system fault points.

III. The Dedicated Dry Desulfurization Air Classifying Grinding Mill Specifically Solves All Industry Pain Points

Aiming at the characteristics of sodium bicarbonate material and the hard indicators of the SDS dry desulfurization process, the integrated dry desulfurization grinding mill is specifically optimized from principle, structure, and control system to solve the shortcomings of traditional equipment one by one:

Pain Point 1: Uneven Particle Size, Low Desulfurizer Utilization

Solution: A built-in independent variable-frequency centrifugal classification wheel automatically returns coarse material for secondary grinding, stably locking the finished D90 in the optimal 10-25 μm desulfurization range, with a narrow particle size distribution bandwidth and sufficient sodium bicarbonate decomposition. Measured desulfurizer unit consumption drops by 25%-40%, directly saving huge consumable costs in long-term operation. The classification wheel speed is steplessly adjusted on the touch screen, switching fineness with one button for high and low sulfur loads, adapting to flue gas concentration fluctuation conditions.

Pain Point 2: Sodium Bicarbonate Caking by Moisture and Heat, Frequent Pipe Blockage

Solution: 1. Low-temperature-rise flow field design in the chamber carries away grinding friction heat, avoiding high-temperature decomposition and soft sticking of sodium bicarbonate. 2. Fully negative-pressure enclosed airflow conveying, with powder suspended in the pipe without deposition dead corners. 3. Hydraulic quick-open cabin door of the main machine allows regular quick cleaning of residual material in the chamber, eliminating moisture caking hazards and keeping injection pipes clear for a long time.

Pain Point 3: Fast Wear of Wear Parts, Frequent Maintenance Causing Production Loss

Solution: The grinding hammer and ring gear use high-wear-resistant alloy materials, impact-resistant, weak-acid corrosion-resistant, greatly extending the replacement cycle of wear parts. The modular disassembly structure allows replacing hammers and seals without disassembling the whole machine, completing a single maintenance within half an hour, greatly reducing boiler shutdown losses. The whole system sets multiple protections for overload, over-temperature, and vibration limit, reducing the probability of abnormal equipment damage.

Pain Point 4: Equipment Dust Leakage, Workshop Failing Environmental Standards

Solution: The whole-process negative-pressure closed-loop grinding process forms a complete negative-pressure loop among the grinding host, feeding bin, conveying pipe, and dust collector. All dust is centrally recovered by the pulse bag dust collector, with no overflow point, the workshop air quality meets standards, avoiding environmental dust penalty risks. The equipment has overall noise reduction treatment, with operating noise controlled within the industrial allowable range.

Pain Point 5: Low Automation, High Manual Operation Cost

Solution: A complete set of PLC intelligent linkage control system centrally controls the grinding host, classification motor, variable-frequency feeder, and induced fan parameters on the touch screen for visual operation; it can access flue gas online monitoring data and automatically fine-tune the feeding amount and powder fineness according to real-time SO2 concentration, achieving unattended fully automatic operation, requiring only regular inspection, saving manual management costs. It also supports multiple boilers sharing one grinding host to increase equipment utilization.

Pain Point 6: Bulky Equipment with Large Footprint, High On-site Retrofit Difficulty

Solution: Vertical compact integrated body, highly concentrated, no heavy concrete foundation needed, simple and quick lifting, installation, and connection to the flue injection system, even a small old boiler room can be smoothly laid out, greatly reducing engineering retrofit cycle and civil investment.

IV. Small Selection Suggestions for Dry Desulfurization Grinding Mills Under Different Working Conditions

Municipal waste incinerators and hazardous waste incinerators: high HCl concentration in flue gas, give priority to ultrafine grinding models with D90 ≤ 18 μm, with deacidification efficiency reaching 99%. Small and medium coal-fired hot water boilers and biomass boilers: conventional standard model with D90 = 20 μm is sufficient, balancing desulfurization effect and operating energy consumption. Multi-kiln centralized treatment projects: configure a large-capacity grinding host plus a branch conveying injection system, one set of equipment supplying multiple flue gas points, reducing total equipment investment. Explosion-proof workshops and chemical enclosed workshops: can customize the whole machine dust explosion-proof version, with explosion-proof motors, explosion-proof electrical control, and anti-static pipes, meeting safe production standards.

V. Conclusion

Environmental equipment selection cannot only look at the initial purchase price, but must account for the comprehensive cost of operation and maintenance, consumables, and energy consumption over the 3-5 year full life cycle. Traditional general grinding equipment seems cheap to buy, but brings a series of chain losses such as reagent waste, frequent shutdown and repair, and environmental penalty for exceeding standards. The integrated dry desulfurization air classifying grinding mill is equipment tailored to the SDS sodium bicarbonate dry desulfurization process, with the core advantages of stable operation and low operation and maintenance costs, escorting the long-term ultra-low emission of industrial flue gas, truly realizing the two-way optimization of environmental compliance and production cost.