Method for automated preventive cleaning of ventilation systems and device for its implementation

Abstract

FIELD: mechanical engineering.SUBSTANCE: invention relates to the field of automatic preventive cleaning of air ducts of ventilation systems in industrial enterprises, public catering facilities, medical institutions and commercial real estate. The method of automated preventive cleaning of ventilation systems is implemented by a device that includes spray nozzles installed in the inlet sections of air ducts and / or before sections of the route with an increased rate of contamination, contamination sensors located in areas of maximum particle deposition, preferably on the inner wall of the first turn (bend) of the air duct, a tank for a cleaning agent, a high-pressure pump, a hydraulic distributor with electromagnetic valves, a control unit based on a programmable logic controller, and includes detection by highly sensitive sensors of a monomolecular layer of contamination, the supply of an aerosol of a micellar solution of a surfactant and the removal of the detected contaminants without stopping the operation of the ventilation system and changing its operating mode.EFFECT: increased fire safety, improved air quality and energy efficiency of ventilation systems by preventing the accumulation of combustible deposits (in particular, lipid deposits), automating the cleaning process without stopping production, and reducing operating costs by eliminating the need to involve third-party services.3 cl, 1 dwg

Description

[0001] The invention relates to the field of fire safety, labor protection, ventilation and air conditioning and can be used for automatic preventive cleaning of air ducts of ventilation systems in industrial enterprises, public catering facilities, medical institutions and commercial real estate.

[0002] Various methods for cleaning ventilation systems are known, including mechanical cleaning with brush machines and robots, chemical cleaning using aggressive reagents, cryogenic cleaning with dry ice, and automatic disinfection systems. The common disadvantages of these methods include the need to completely shut down the ventilation system, high labor intensity, the risk of damage to the air ducts, and the lack of preventative effect, as they are aimed at removing already formed deposits.

[0003] A known method of steam cleaning (patent SU1466824A1) involves introducing water vapor into air ducts to prevent the adhesion of oily contaminants. Its significant drawbacks include: high energy consumption due to the need to generate steam; the risk of corrosion of metal air ducts due to constant moisture condensation; the creation of a "wet adhesion" effect, which promotes particle adhesion; potential damage to equipment; difficulty in integrating into existing systems due to the inconsistency of the air duct configuration with the method requirements; and the lack of the possibility of full automation for high-frequency preventive cleaning.

[0004] Also known is a method for disinfecting supply ventilation and air conditioning systems and a ventilation system for implementing the method (patent RU2519668C1). Its significant drawback is the inability to remove contaminants.

[0005] The main features of the invention are the automatic detection of the initial stage of contamination of the inner surface of air ducts using monomolecular layer sensors that record the formation of a monomolecular layer of contaminants, primarily in the zone with the highest rate of contaminant deposition in the air duct; the supply of a finely dispersed aerosol of a micellar solution of surfactants with a concentration close to the critical micelle concentration (CMC) directly into the operating air duct without stopping the ventilation system and changing its operating mode; solubilization of contaminants (including lipid ones) inside surfactant micelles in the volume of aerosol droplets, followed by removal of contaminants by the main air flow;implementation of preventive cleaning in a fully automatic mode based on a sensor signal, preventing the polymerization and compaction of deposits before they accumulate in quantities that pose a fire or sanitary hazard.

[0006] The technical result of the invention is to increase fire safety, improve air quality and energy efficiency of ventilation systems by preventing the accumulation of combustible deposits (in particular, lipid deposits) while maintaining the continuity of operation of the system.

[0007] The specified technical result is achieved by the fact that the automated system for preventive cleaning of ventilation ducts contains:

[0008] • spray nozzles installed in the inlet sections of air ducts and / or in front of sections of the route with increased pollution velocity;

[0009] • pollution sensors placed in areas of maximum particle deposition, preferably on the inner wall of the first turn (bend) of the air duct;

[0010] • tank for cleaning agent;

[0011] • high pressure pump;

[0012] • hydraulic distributor with electromagnetic valves;

[0013] • control unit based on programmable logic controller (PLC).

[0014] The cleaning agent used is an aqueous solution of surfactants with a concentration equal to or close to the critical micelle concentration (CMC) for the formation of round Hartley micelles. The reagent is selected based on the reagent composition. Biodegradable nonionic surfactants are preferred.

[0015] The reagent is supplied to the air duct in the form of a finely dispersed aerosol with a droplet size that ensures their effective transfer by the main air flow along the entire length and cross-section of the air duct.

[0016] Mechanism of action: Aerosol droplets, moving with the airflow, come into contact with the contaminated surface of the walls. Surfactant micelles within the droplets exert a localized effect at the point of contact. When the droplet contacts the deposit, the following occurs:

[0017] a) Adsorption of surfactant molecules at the interface, a sharp decrease in the adhesion of contamination;

[0018] b) Solubilization (inclusion) of hydrophobic particles of fat / oil into the hydrophobic cores of micelles located in the volume of the drop;

[0019] c) Aerodynamic forces of the flow detach the droplet from the wall along with the captured (solubilized) contaminants and carry them further through the system for subsequent removal;

[0020] Thus, cleaning occurs due to the dynamic contact and detachment of aerosol droplets, which ensures continuous and distributed action over the entire internal surface without moisture accumulation.

[0021] The preventive control principle based on the detection of the initial stages of pollution, according to this invention, includes:

[0022] • Location of sensors: Sensors are installed at a critical point - the first bend of the air duct, where contaminants accumulate first and most intensively.

[0023] • Sensitivity: The sensors are configured to detect the initial forms of contamination, at the level of a monomolecular layer of contaminants that have high adhesion.

[0024] • Operation logic: The system is activated not by significant contamination, but to prevent it. A signal from the sensor indicating the beginning of the formation of an active adsorption layer serves as a trigger for cleaning before polymerization and compaction of deposits occurs.

[0025] • High-frequency cleaning automation: The control unit initiates short cleaning cycles based on signals from highly sensitive sensors. The aerosol sprays the reagent without interrupting the main ventilation system. The treated and solubilized particles are carried away by the main air flow.

[0026] A highly sensitive sensor detects the monomolecular layer and sends a signal to the control unit. The control unit, in turn, activates the release of a micellar surfactant aerosol. This aerosol, with its high penetrating and solubilizing properties, effectively removes contaminants at the earliest stage when they are detected. This maintains the internal surface of the air duct in a condition that prevents the accumulation of combustible deposits, which is achieved fully automatically, without human intervention or system downtime.

[0027] The invention is explained by drawings, where Fig. 1 shows a diagram of the preventive cleaning system.

[0028] The device for implementing the method includes pneumatic spray nozzles 8 installed on the straight inlet section of the air duct. Alternatively or additionally, the nozzles can be installed immediately before the first bend in the route. Pollution sensors 1 are installed on the inner wall in the area of ​​the first bend (turn) of the air duct, where the most intense deposition of aerosol particles is observed due to changes in the flow dynamics, as well as in the initial section. Sensors 1 can be implemented in the form of optical sensors recording changes in the reflectivity of the surface, as well as in the form of capacitors. Tank 5 with a reagent - an aqueous solution of a surfactant with a concentration of ~KKM, located outside the service area in a place accessible for refilling. High-pressure pump 4, driven by electric motor 3, provides reagent supply to the main line. Hydraulic distributor with electromagnetic valves 6, distributing the reagent flow to groups of pneumatic nozzles 8.High-pressure pipelines 7 connect the hydraulic components of the system. Control unit 2 is PLC-based and located in the control cabinet. Unit 2 is electrically connected to sensors 1, electric motor 3, and distributor valves 6.

[0029] Optical sensors 1, configured to detect a film of oil pyrolysis products, are installed in the area of ​​the most intense contaminant deposition, presumably at the air duct inlet and at the first bend in the main air duct after local exhausts. Upon detecting initial contamination, control unit 2 starts electric motor 3. The electric motor drives high-pressure pump 4, which pumps the reagent. The control unit actuates distributor 6, determining the direction to the exhaust opening that requires cleaning. The reagent is delivered through extended high-pressure pipelines 7 to a group of pneumatic nozzles 8. The aerosol passes through the air duct at high speed and pressure, impacting the walls and removing deposits with the gas-air flow. The final point of the route is fan 9, which removes the spent aerosol from the ventilation system.

[0030] The invention can be used in the following areas: public catering establishments (restaurants, cafes); food industry; medical institutions; industrial enterprises (chemical, metalworking); retail and office real estate.

[0031] The greatest effect is achieved where regular maintenance of clean air ducts is required to comply with fire safety and sanitation standards.

Claims

1. A method for automated preventive cleaning of ventilation systems, including detection of contaminants, supply of a cleaning agent in the form of an aerosol and removal of contaminants by an air flow without stopping the operation of the ventilation, characterized in that using highly sensitive sensors, the moment of formation of the initial monomolecular layer of contaminants is recorded; based on a signal from the sensors, a short-term spray of a finely dispersed aerosol of a micellar solution of surfactants (surfactants) is carried out with a concentration close to the critical micelle concentration; In this case, particles of contaminants are solubilized within the surfactant micelles in the volume of aerosol droplets and are carried away by the main air flow, preventing polymerization and compaction of deposits.

2. A device for implementing the method according to claim 1, comprising spray nozzles installed in the inlet sections of air ducts and / or in front of sections of the route with an increased pollution rate, pollution sensors located in areas of maximum particle deposition, preferably on the inner wall of the first turn (bend) of the air duct, a tank for a cleaning agent, a high-pressure pump, a hydraulic distributor with electromagnetic valves, a control unit based on a programmable logic controller (PLC), characterized in that the cleaning method is implemented without stopping the operation of the ventilation system and changing its operating mode, wherein the pollution sensors are designed with the ability to detect a monomolecular layer of pollution, and the spray nozzles are designed with the ability to supply an aerosol of a micellar solution of surface-active substances (SAS).

3. The device according to paragraph 2, characterized in that the monomolecular layer of contamination sensors are installed on the inner wall in the zone of the most intense deposition of contamination.

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