Light granular laundry powder production process using spray tower separation method

Abstract

This design is a process for producing lightweight granular laundry detergent using a spray tower separation method; the conventional method is spray drying (expensive, high investment, high energy consumption), and extrusion methods produce a dense product (high density of granules, more difficult to control moisture, and faster spoilage); the present design presents a two-stage combined drying and structuring process that combines spray tower-free methods (lower investment) with the final product quality of the spray drying method (puffed granules); in this method, the initial slurry is carefully controlled with the amount of The moisture is converted into an extrudable paste and then passed through a simultaneous extruder and cutter to form granules of uniform size. These granules are dried in a reciprocal manner by hot air flow, becoming porous and lightweight. Simultaneous control of the water-solids ratio, extruder pressure and thermal flow pattern creates a stable particle structure. After the drying and impact cooling stage, non-uniform particles are separated by a screen and returned to the cycle. This method achieves a process for producing laundry powder with low bulk density and suitable granular structure without relying on a spray tower.

Description

Description of the invention Title of the invention Light granular laundry powder production process using spray tower separation method Technical background of the relevant invention The present invention is in the field of chemical engineering and materials processing, specifically in the field of manufacturing dry detergents, namely laundry powders. This process is a hybrid process that uses the principles of fluid mechanics, mass and heat transfer, and detergent chemistry to produce a final product with desirable physical properties. The main objective is to achieve a lightweight, low bulk density (fluffy) formulation that is economically and operationally viable. Technical problem and stating the objectives of the invention - Failure to achieve a puffy form (with a porous interior) in the granules produced by current designs. -The produced granules are heavy due to the higher water content; this causes the product to spoil more quickly. - In powder form, transportation is more difficult due to the lack of compaction and the particles are dispersed. - It is not possible to control the exact amount of powder due to the uncertainty of the measurements. - Using granules at different stages of production creates less pollen. -High cost of production lines, especially spray dryers (requires very tall towers and very high energy consumption). -Complexity of lines and need for skilled operators. -Objectives of the invention: The production line in this design has a lower investment cost; its use is simple and does not require a skilled operator; the produced powder granules have a puffy state (porous internal form) and are light; by using precise mechanical steps to define the geometry of the particles, it is possible to control the size and shape of the particles; also, the production line defined in this design has the necessary flexibility to apply the desired changes to the chemical formulation of the materials, to produce various types of powders (manual and mechanical). A description of the state of the prior art and the history of developments related to the claimed invention. No similar case was found in the domestic patent search system; the following related cases were found in international patent registrations: US4134725A In the field of powder detergent production, various methods have been developed. For example, reference is made to patent number 000111111. This patent describes a method that involves granulation based on the application of a granulating liquid (such as a concentrated solution of surfactants or adjuvants) to a basic organic powder (such as sodium carbonate or zeolite) and then gradual drying. Although this method uses the application of a liquid to bind the particles; it often faces challenges in controlling the moisture content and maintaining the puffed structure at large scale. EP0215637A2 The present invention, relying on a specific combination of mechanical operations and careful control of moisture in the initial and final stages, attempts to create a puffed structure through control over evaporation and internal expansion. A particulate detergent composition is prepared by spray drying a slurry containing a surfactant system, which may include anionic surfactants, nonionic surfactants and / or soaps, a non-phosphate builder such as an aluminosilicate or alkali metal carbonate, and a sugar such as sucrose or sorbitol. This sugar provides sufficient structure to the powders without the need for the use of sodium silicate. This method also involves the expense and complexity of a spray tower. US8901065B2 The present invention relates to a process for preparing a spray-dried detergent powder comprising: (a) forming an aqueous detergent slurry in a mixer; (b) transferring the aqueous detergent slurry from the mixer to a pipe that is directed from a first pump and then from a second pump to a spray nozzle; (c) contacting a liquid detergent with a viscosity of less than 2 pascal seconds with the aqueous detergent slurry in the pipe, after the first pump and before the second pump, to form a mixture; (d) spraying the mixture through a spray nozzle into a spray drying tower; and (e) spray drying the mixture to form a spray-dried powder, in which a nitrogen-rich gas is injected between the first and second pumps. This is a standard industry method, but is associated with disadvantages such as high economic costs and high energy consumption. The washing powder production line in active industrial manufacturers currently uses two common methods: spray tower and tower-less; a brief description of these methods is given below: Spray tower method (spray dryer): The spray tower method of washing powder production line includes various stages of mixing raw materials, drying using a spray tower, and finally packaging. This method is very common in the powder production industry due to its efficiency and high quality of the product produced. Production steps: The powder production process generally includes the following steps: Mixing the raw materials: Dry ingredients (fillers, builders, and additives) are mixed in a large industrial mixer, then liquid ingredients (surfactants, fragrances, etc.) are slowly added to the mixture. Homogenization: The mixture obtained from the previous step is homogenized by a homogenization device to achieve a uniform structure. Pump and spray: The homogenized mixture is transferred to the spray device in the spray tower by a high-pressure pump. Spray tower drying: In the spray tower, the mixture is sprayed into fine droplets and dried with a stream of hot air. This process of homogenization and drying is carried out simultaneously, ultimately creating a dry powder with hollow grains. Cooling and filtration: The final powder is prepared for packaging after cooling and filtration. Packaging: The final powder is prepared for packaging after drying and filtration. Advantages of the spray tower method: High speed and accuracy: This method increases production speed and accuracy. Good final quality: The dried powder is of high quality with hollow grains and a uniform structure. High efficiency: The efficiency of this system is high compared to similar systems. Its disadvantages are very high initial investment, huge thermal energy consumption, and the need to maintain precise slurry viscosity. Powder production without spray tower: The spray tower-free method is one of the most common and desirable methods in the detergent industry; it is considered due to the lack of need for complex equipment, resulting in lower investment and the possibility of building small and medium-sized production units. The operating process of such systems is as follows: The raw materials, which include the following: 1.Surfactants: including sodium lauryl ether sulfate (SLES) or sodium decylbenzene sulfonate (LABSA) 2. Manufacturers: Sodium tripolyphosphate (STPP) or zeolite 3. Fillers: such as sodium sulfate 4. Additives: such as enzymes, bleaches, perfumes, stain removers and anti-fouling agents The following steps are combined in order; the production steps are as follows: 1. Dry mixing: In this step, solid materials are mixed in an industrial mixer to create a homogeneous mixture. 2. Adding liquid ingredients: After mixing the dry ingredients, liquid ingredients such as surfactants and fragrances are added to the mixture. These ingredients should be added slowly to prevent clumping. 3. Granulator: In this stage, the dry mixture enters the granulator to create powder particles of specific, constant and uniform sizes for packaging. This process can be created by pressing or extruding machines. 4. Drying: The output materials of the granulator contain some moisture, which is then fed into the rotary tunnel dryer for drying. 5. Sieving: The output of the drying tunnel enters the sieve to separate the inappropriately sized particles (fine and coarse) from the grains and return them to the line. 6. Packaging: The produced powder is packaged in packages of different weights depending on the order for household or industrial use. Advantages of the non-tower method over the spray tower method: Lower investment cost: The equipment used is simpler and cheaper than the spray tower method.  Greater flexibility: It is possible to produce a variety of products with different formulations. Lower energy consumption: Due to the lack of need for intense thermal processing, energy consumption is reduced. Its disadvantages include producing dense and heavy grains, not achieving an ideal puffed structure, and difficulty in controlling particle size. Providing a solution to an existing technical problem along with an accurate, sufficient, and integrated description of the invention The present design presents a two-stage drying and structuring process that combines the advantages of spray tower-less methods (lower investment) with the quality of the final product (puffed granules) of the spray dryer method. (Figures 1-3) shows the general schematic of the production line. (Figure 4) The various components of the production line are numbered and named in the order of use; Preparation and ingredients of the powder: The detergent powder produced consists of the following ingredients; surfactants including sodium lauryl ether sulfate, sodium dodecylbenzene sulfate, sodium lauryl sulfate; builders that soften hard water such as sodium tripolyphosphate; fillers such as sodium sulfate; additives such as perfume, polymer, bleach, anti-scalant that help with washing quality; liquid sodium silicate and caustic soda and lime powder for alkalization and improving washing quality; stearic acid as a softener and water (65 to 70%), alkaline liquids, caustic, sodium silicate (30 to 55%), caustic soda (30 to 40%), zeolite and Glauber's salt, sulfonic acid, water (65 to 70%), sodium silicate, sodium carbonate, pentasodium. Powder production steps: Preparing the slurry: The first step in the production of detergent powder is to mix liquid and solid materials together. In the slurry preparation unit, which depends on the different detergent compositions, (Figure 5), various liquid and solid materials are heated and these solids are converted into liquids. They are introduced into the weighing tank by slow shaking; this action makes the materials stable and uniform. The weighing tank is equipped with weighing sensors; which instantly measure the weight of each material entering the weighing tank and give the tank corresponding to each material the order to enter or stop the material based on the percentage of the composition, which is controlled by the intelligent PLC control system. (Figure 9) The amount of water added at this stage is very important. Typically, the moisture content of the initial slurry should be within a range that allows for the formation of an extrudable paste without being too watery (65 to 70% by weight solids to 30 to 35% by weight water). Homogenization: The slurry enters the ribbon mixer tank, homogenizes; integrates and empowers multiple interacting elements, with minimal dry lumps or moisture-laden pellets; moisture distribution throughout the powder mass should be uniform. (Figures 12 to 16) Hot weather: For better mixing, the mixture is in the form of a slurry. In the further process, its moisture content needs to be reduced, so the slurry mixture enters a heating chamber equipped with hot air blowers and is heated. (Figure 10-11) The temperature of this stage is carefully controlled (e.g. 70 to 117 degrees Celsius). The goal is to quickly evaporate a small portion of the free water so that the mixture becomes an extrudable paste. Granulator: The dough enters a screw (Figure 6-7) and is directed towards the hot air tunnel; inside the hot air tunnel, the mixture moves slowly forward and hot air is blown at the same time to reduce the moisture content of the powder mixture as much as possible and at the end of the tunnel its moisture content reaches the standard production value. Then this lumpy mixture is passed under pressure through an extruder (screw extruder) fitted with a matrix (with 1 to 3 mm holes), then it is cut by a rotating cutting blade fitted on the extruder head. In this way, fine powder grains are formed. (Figure 8) Rotary dryer: To achieve particle adhesion and granule formation, the dough needs to be moist, but after the granules are produced, the moisture must be reduced to prevent adhesion and clumping; it is at this stage that the granules enter the rotary drying tunnel and lose most of their moisture under direct heat (final moisture 5 to 8 percent). Hot air is blown in a co-directional or cross-flow manner from inside the rotating drum, and the rotary motion causes continuous mixing of the granules and uniformity in drying. (Figure 18-20) Crusher: Before entering the drying tunnel, the granules may stick together due to moisture and adhesion, and clumps may be observed at the dryer outlet; to solve this problem, the materials are fed into a blade crusher and the clumps are broken up. (Figure 24) Screen: The crusher output may contain granules that are different from the defined size; to solve this problem, the material is screened and the particles that are finer and larger than the defined size are separated and returned to the line for correct sizing. (Figure 21) Drying tower: This step is the most important part of the design; the produced granules, which have a relatively dry shell and a wetter core, are discharged from the top of the puffing tower. Hot air at a very high temperature (e.g. 157 to 277°C) is blown from the bottom of the tower in an updraft. (Figure 22) Puffing mechanism: Hot air quickly hits the surface of the granule and heat is transferred to the outer layer. This heat causes the sudden evaporation of moisture trapped in the core of the granule and creates internal vapor pressure; since the outer shell has hardened somewhat in the previous stage, this internal vapor pressure swells the granule structure and makes it porous inside. Heat control: The residence time in this tower is very short (a few seconds to a minute) to prevent thermal degradation of active ingredients (such as enzymes and bleaches); as a result, the bulk density of the granule is significantly reduced and the final product has puffy characteristics. Female enzyme: Protease, amylase and lipase enzymes, essential oils (fragrance) and colorants (if needed) are added to the mixture; depending on the type of powder application, in machine, manual, household or industrial types, etc., essential oils, fragrances, stain removers, etc. are added to it and, in order to make it uniform, it is put back into the mixer (at a low temperature, usually below 40 degrees Celsius, which prevents thermal decomposition of enzymes and evaporation of essential oils); the base powder and all other ingredients are mixed uniformly. (Figure 23) Mixer: To ensure mixing and homogenization of the ingredients, the powder mixture is fed into a paddle mixer and homogenized by rotating blades (Figure 24). Final packaging: Due to the bulky and light nature of the powder, the powder enters the gravity packaging section and in the final packaging stage of the product, the detergent is packaged in plastic bags, pouches, etc. using a semi-automatic gravity method, due to the low density of the granules, with a volumetric filling system. (Figure 25) Explanation of shapes, maps and diagrams Figure 1 - General schematic of the laundry detergent production line Figure 2 - Side view of the laundry detergent production line Figure 3 - Front view of the laundry detergent production line Figure 4- Various components of the laundry detergent production line: 1- Soft water tanker, 2- Acid and additive liquid tanks, 3- Powder conveying screw, 4- Weighing (with load cell) with conveyor, 5- Conveyor, 6- Upper hopper, 7- Ribbon mixer, 8- Hot air tunnel, 9- Granulator, 10- Rotary dryer, 12- Inclined conveyor, 13- Blade crusher, 14- Industrial screen, 15- Edged inclined conveyor, 16- Cooling tower, 17- Maroon, 18- Essential oil tankers, 17- Mixer, 18- Inclined conveyor, 19- Bag grabber (bulk packaging system) Figure 5- Acid and additive fluid tanks: 1-Tank, 2-Chassis, 3-Solenoid Valve, Powder additive tanks containing materials: 1- Alkaline liquids, 2- Caustic, sodium silicate, 3- Caustic soda, 4- Zeolite and Glauber's salt, 5- Sulfonic acid, 6- Sodium silicate, 7- Sodium carbonate, 8- Pentasodium Figure 6 - Powder conveyor screw Figure 7- Various components of the powder conveyor screw: 1- Geared electric motor, 2- Shell, 3- Screw, 4- Bearing, 5- Support base Figure 8- Granulator screw and its various components: 1- Electric motor, 2- Gearbox, 3- Body, 4- Screw, 5- Granulator with cutting blades Figure 9- Weighing conveyor belt (with load cell) and its various components: 1- Gearbox alternator, 2- Conveyor belt chassis with hubs, 3- Load cell chassis, 4- Conveyor belt Figure 10 - Hot air tunnel including components » 1- Material transfer conveyor chassis, 2- Conveyor, 3- Hot air blowers, 4- Hot air tunnel, 5- Chassis Figure 11 - Three views of the hot air tunnel with material transfer conveyor Figure 12 - Edged conveyor belt for transporting materials Figure 13 - Ribbon mixer Figure 14- Various components of the mixer: 1- Shell, 2- Bearing and coupling shaft, 3- Shaft, 4- Mixer paddles, 5- Material discharge jack valve Figure 15- Industrial ribbon blender (mixer): 1- Upper hoppers, 2- Mixer, 3- Lower hopper with jack Figure 16 - Mixer and hopper support structure Figure 17 - Soft water tanker Figure 18 - Rotary drying tunnel Figure 19 - Three views of the rotary dryer tunnel Figure 20 - Various components of a rotary drying tunnel 1- Chassis, 2- Inclined belt for rapid material transfer to the outside, 3- Bearing, 5- Gearbox, 6- Electric motor, 7- Shell, 8- Hot shell retaining ring, 9- Gear, 10- Smooth blades for smooth material transfer, 12- Outer shell, 13- Soft material transfer blades in front of the blower, 14- Hot air blower, 15- Effective metal belts (retaining) between the hot shell and the outer ring Figure 21 - Industrial sieve Figure 22- Drying tower Figure 23- Essential oil and enzyme reservoirs, respectively, including the following reservoirs: 1- Protease enzyme 2- Amylase enzyme 3- Lipase enzyme 4- Essential oil The various components of the female enzyme system include: 1- Book gearbox dynamo, 2- Screw with jacked discharge valve, 3- Material tanker Figure 24- Three views of the mixer: 1- Gearbox, 2- Dynamo, 3- Shell, 4- Blade Figure 25 – Packaging line and its components: 1- Inclined edge conveyor, 2- Bag grabber (bulk packaging system) A clear and precise statement of the advantages of the claimed invention over prior inventions. - Lower investment cost; By replacing very expensive spray drying towers, the initial cost of the production line is significantly reduced. - Flexibility in product type and composition; with more precise control of the extrusion stage, it is possible to quickly change the formulation and granule size to produce more specialized products (such as machine or hand powder). - Lower energy consumption; eliminating or reducing initial intensive drying steps (such as spray drying) that require huge thermal energy; reduces overall process energy consumption. - Simplicity and ease of operation; the steps are designed in such a way that the operation, troubleshooting, and maintenance of the equipment (compared to highly complex spray drying towers) are simpler. - Creating a puffy and light form in granules; by engineering the internal structure through evaporation control in the puffing tower, the final product has a low apparent density that requires less volume consumption for washing and instills a sense of lightness in the packaging. Description of at least one implementation method for implementing the invention The materials required for powder production are in two forms: main and base materials, which are in solid and liquid forms, and additives (essential oils, stain removers, etc.), which are prepared and stored in special tanks based on the amount of production. The weight percentage of the required amounts of base materials is measured depending on the type of production and its application (manual or machine powder, as well as household and industrial uses), and after the initial mixture and slurry form, which is heated after mixing and, by reducing the moisture, takes a malleable paste form, and after passing through extrusion with pressure through fine holes and simultaneous cutting of the output sections, granules are formed (fine powder grains). The remaining moisture in the grains is removed again by applying heat and in a mixer that simultaneously breaks the materials, the stuck grains are broken and the output of the materials is sieved and the grains outside the size are separated and returned to the line.The granules with defined dimensions are released from the top of the drying tower and become hollow cores due to the impact of hot air; also in this case, the adhesion of the granules to each other is completely destroyed and the powder grains are completely separated. Before the packaging stage, the powders are mixed with different enzymes depending on the quality level of production and order, which enzymes adhere to the outer wall surface of the powders and its distribution becomes uniform inside a mixer. The produced powder is ready for packaging, which can be packaged in bulk or bags in different weights by directing it to the packaging unit and entering the market. Explicit mention of the industrial application of the invention Production of manual or machine-made laundry powder for home use and production of granular detergents for any type of home and industrial washer.

Claims

Claim What is claimed: Claim 1) The process for producing light granular laundry powder includes the following steps: preparation of the initial slurry including the combination of surfactants (anionic such as sodium lauryl ether sulfate, sodium dodecyl benzene sulfate or sodium lauryl sulfate), builders (such as sodium tripolyphosphate, zeolite), fillers (such as sodium sulfate), and additives (perfume, enzyme, bleach, anti-scalant); controlled homogenization of the mixture in a ribbon or tape mixer until an extrudable paste is formed; extrusion of the paste through a pressurized screw from matrices with 1 to 3 mm openings and simultaneous cutting of the output sections to produce primary granules; drying of the granules in a rotary drying tunnel or separation tower with hot air blowing in a co-directional or cross-flow method until reaching a final moisture content of 5 to 8 percent; - Applying a controlled puffing process to create a porous internal structure and low bulk density; adding protease, amylase, and lipase enzymes and essential oils in the final mixer at a temperature below 40 degrees Celsius to prevent the destruction of sensitive compounds; sieving and final packaging of the product in a volumetric packaging unit;So that the above combination and steps lead to the production of granular powder with a fluffy, light structure, low apparent density, and rapid solubility in water. Claim 2) According to claim 1, the weight ratio of solids to water in the initial slurry stage is adjusted between 65 to 70 percent solids and 30 to 35 percent water to achieve a paste-like characteristic suitable for extrusion. Claim 3) According to claim 1, a hot air tunnel with precise temperature control in the range of 70 to 117 degrees Celsius is used for rapid evaporation of the free moisture portion. Claim 4) According to claim 1, the output granules have an apparent density between 0.3 and 0.5 grams per cubic centimeter and have a porous internal structure. Claim 5) According to claim 1, using a mechanical extrusion system and a rotary dryer, it replaces the spray drying tower and significantly reduces energy consumption and initial investment costs. Claim 6) According to claim 1, through the puffing process and humidity control, it provides high flexibility for the production of manual or machine powders with different formulations. Claim 7) According to claim 1, the final products have an external surface suitable for absorbing enzymes and essential oils, and with uniform distribution of enzymes on the surface, washing efficiency is optimized.

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