RU2024611C1 - Process for preparing granular synthetic detergent - Google Patents

Abstract

FIELD: chemical engineering. SUBSTANCE: process for preparing a granular detergent is carried out by separating powders into two streams. One of the streams is sprayed and first dried, posterior dried and granulated in the boiling bed liquefied by an ascending current of the heat carrier. 40-60% powdery components of the total weight of the product are introduced into the zone of the boiling bed. The drying is previously carried out in a descending current of the heat carrier. The ascending to descending current rate/ratio is 12-18 on the evaporating surface of the boiling bed. EFFECT: improved properties of the synthetic detergent. 1 dwg, 2 tbl

Description

 The invention relates to methods for the production of granular products, namely, the production of synthetic detergents (SMS).

 A known method of producing granular SMS in the apparatus of the VKS (NIITEHIM, Overview, Production of synthetic detergents and cleaners by non-towed methods, 1983, p.25-34) by dry mixing of the original powder components in a continuous pre-mixer followed by spraying the liquid components on a dry base in suspension.

 The disadvantages of this method are the insufficient strength of the obtained granules, the restriction on the introduction of liquid components and the unstable chemical composition of the finished product.

 There is also a method of producing granular SMS based on surfactants and sodium tripolyphosphate (TPPN) (former USSR St. N 910760, class C 11 D 11/02, 1980) by preparing an aqueous solution of SMS components, spray drying the resulting solution followed by hot granules and fine TPFN in the amount of 5-25 wt.% in the cooling zone.

 The disadvantages of this method are also insufficient strength, low bulk density of the finished product and its unstable chemical composition.

 As a prototype, a method for producing a synthetic detergent was chosen (application N 4691717 / 23-04 from 05.15.89) by mixing components including a nonionic surfactant and non-thermostable additives, dividing the resulting composition into two streams, followed by spray drying of one of them, constituting 80-98% by weight of the composition and mixing with non-thermostable additives while spraying the rest of the composition in a fluidized bed apparatus.

 In this case, the finished product is obtained by contacting a mixture consisting of an SMS composition (2-20%) and nonionic surfactants with dried powder granules after spray drying (humidity 10%) and particles of thermostable components, and its quality characteristics (bulk density and strength of granules ) are determined mainly by the characteristics of the granules after spray drying (for the Lotus-automatic formulation, their share in the mixer is 66-81%).

As a result, the resulting product has a relatively low bulk density (up to 440 kg / m ³ ) and pellet resistance to fracture.

 The aim of the invention is to increase the bulk density and strength of the granules.

 This goal is achieved by the fact that in the process of obtaining granular SMS, by separating the powder and liquid components of the detergent into two streams, spraying and pre-drying one of the streams, followed by drying and granulation in a fluidized bed liquefied by an upward flow of coolant, they are introduced into the fluidized bed zone 45-65% of the powdered components of the total product mass and pre-drying are carried out in a downward flow of coolant with a ratio of the speeds of downward to upward flow of coolant at the level of the mirror of the fluidized bed, equal to 12-18.

 The drawing shows a diagram of a method for producing granular SMS.

 The method can be implemented in a combined drying and granulation apparatus of type RG, containing zone 1 for spraying and drying in a downward flow of coolant, zone 2 for the formation and drying of granules in a fluidized bed, lines 3 for introducing an SMS composition, 4 for entering a coolant, 5 for introducing powdered components into a boiling layer, 6 introducing the coolant into the fluidized bed for liquefaction, 7 removal of the finished product, 8 removal of the spent coolant.

 The method of obtaining granular SMS is as follows.

Best composition consisting of the liquid components, additives and small loose parts powdered components introduced through line 3 into the spraying and drying zone 1. The jet of atomized composition flue gases with a temperature of 300-700 ^C. The powder components are added through line 5 in an amount of 45-65 % of the total amount of product obtained, including all powdery unstable components, such as TPPN, sodium perborate, sodium bicarbonate.

 Droplets dried in the downward fluid stream, consisting of surfactants by 27-57%, fall into the fluidized bed of dry dust-like particles of raw materials at a certain speed, which helps to increase the drying rate and reduce energy costs.

 As the droplet core is “filled” with dry particles (moisture redistribution and drying acceleration), the process of pellet formation by pelletizing is completed.

 Strong granules of the correct form are obtained, characterized by low porosity, and, accordingly, more uniform in structure.

 The advantages of the proposed method are confirmed by test results.

The experiments were carried out in a laboratory setup, including a granulator dryer type RG with a capacity of evaporated moisture ≈15 kg / h. The initial SMS composition was prepared with continuous stirring in a reactor with a volume of 30 l and a temperature of 60-70 ^about C.

SMS recipes, consisting of a sprayed composition (W _k = 50%) and dry powder components introduced into the fluidized bed by a screw, as well as SMS quality indicators are presented in Table. 1 and 2. As the initial "pillow" used powder SMS "Lotus" with a fractional composition of 0.05-0.15 mm

 Technological modes of drying and granulation.

Coolant flow rate in the spray zone 55.6 kg / h
Fluidizing agent consumption in c.p. 320 kg / h
The temperature at the entrance to the spray zone 300 ^about
Inlet temperature 30 ^о С Temperature in c.p. 45 ^about With
The temperature at the outlet of the apparatus 56 ^about With
Speed ratio
downstream
coolant and recovery
walking fluidizing
agent at the grain level
Kala KS: in experiments 1-4, 9-11 15
in experiments 5-8, respectively 10, 12,
18 and 20.

 Moreover, in the experiments, 1-4 percent of the powdered components introduced into the c. varies from 65 to 40; in experiments 5-8 and 9-11 it remains constant: 65 and 55%, respectively.

 Additionally, on the recipe "Lotus-automatic" was conducted experiment 12 by the method described in application N 4691717/04.

At the same time, a composition was prepared (W _k = 40%) without sodium perborate and nonionic surfactants, divided into two parts, 80% of which was applied to spray drying and 20% in a mixture with nonionic surfactants was sprayed in a fluidized bed apparatus, where the drying product entered the first part of the composition, sodium perborate (15%) and trapped dust.

In the finished product, the following were determined:
Granulometric composition According to GOST 22567.2-77
Bulk density According to GOST 22567.4-77
Sustainability
granules to destruction According to the method
VNIIHIMProeta
Dissolution time According to the procedure
VNIIHIMProekt
Washing ability According to GOST 25644-83.

 The results presented in table 2 are explained as follows. At a constant ratio of speeds equal to 15 (experiments 1-4), the bulk density and the resistance of the granules to destruction monotonously decrease due to an increase in the content of powdery raw materials in the composition and its corresponding decrease in c.c.

 In this case, the transition from experiment 3 to experiment 4 is especially noticeable, when the addition of 5% TPPN to the composition qualitatively changed and hardened the outer shell of the dried droplets, and the excess pressure arising inside the particles inflates the granule and makes it porous (low bulk density and resistance to destruction of granules )

 With increasing values of the ratio of velocities (experiments 5, 6, 1, 7, 8), the bulk density and resistance of the granules to destruction increase and the packing density of the granules reaches such values when their dissolution time sharply increases (experiment 8), which should optimally be no more than 2.5 minutes

 The results are similar to experiments 1-3, 6, 7, obtained on the formulations "Lotus-automatic", "Era-A" and "Oka" (experiments 9-11). In contrast to the prototype (experiment 12), the introduction to c.c. 45-65% of the powdered components can increase the bulk density of the finished product by 12-20% and increase the resistance of the granules to destruction by ≈20% while maintaining at a high level the remaining main characteristics of the finished product - particle size distribution and washing ability.

 At the same time, this will reduce the unit cost of electricity by 1.4 times, fuel by 2.5 times, in addition, an increase in bulk density will reduce the cost of auxiliary materials by 1.2 times.

Claims (1)

 METHOD FOR PRODUCING GRANULATED SYNTHETIC CLEANING PRODUCT by separating the powder and liquid detergent components into two streams, spraying and pre-drying one of the streams, followed by drying and granulation in a fluidized bed, liquefied by an upward flow of heat carrier, characterized in that, in order to increase bulk density and pellet strength, 45-65% of the powdered components of the total product weight are introduced into the fluidized bed zone and preliminary drying is carried out in a downward flow of coolant at wearing the velocities of the coolant descending to the upward flow at the level of the fluidized bed mirror, equal to 12 - 18.

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