Control questions
Explain design of a drying tower.
Which means are used in bunkers of ready product for preventing of powder caking and deposit formation?
Advantages and disadvantages of powders received by spray drying.
Requirements to raw material at production of powders received by drying in boiling layer.
The basic stages of powder drying in boiling layer.
Advantages and disadvantages of product received by boiling layer drying.
3.9 Technology of granulated synthetic detergents by combined methods
Production of powders by combined method includes the following stages: 1) spray drying of composition; 2) neutralization of organic acids by waterless sodium carbonate; 3) mixing of powder, produced by spray drying, with product of neutralization and thermal instable components.
As organic acids alkylbenzolsulphonic and alkylcarbonic acids are used. For completeness of neutralization two-triple surplus of sodium carbonate is used and 5% of water and 5% of sodium hydroxide are added. Neutralization is carried out periodically or continuously at intensive hashing in drum-type mixers, devices with mixers, with boiling and vibratory boiling layer. At periodic neutralization duration of the cycle makes 6-8 minutes.
The technological circuit of powders production by combined method is represented on fig.3.7. Loose raw material is loaded by pneumotransport into account bunkers 1, then it by screw is given to the bunker of weighter 2. From weighter the loose raw material is given in device 3 for neutralization. Alkylbenzolsulphonic and alkylcarbonic acids, non-ionogenic SAS and solution of sodium hydroxide are loaded into neutralizer 3 by pump-weighter 4 after loading of loose raw material. Neutralizer 3 is the mixer at the same time. The powder after neutralizer 3 represents the mix of pentasodiumphosphate, sodium carbonate, alkylbenzolsulphonate, alkylcarboksilate and sodium sulfate. The seeming density of the powder depending on a composition changes from 600 up to 900 kg/m3. The powder is directed to bunker 5, whence by conveyor 6 and air lift 7 it is directed to bunker 8. From bunker 8 powder by conveyor 9 through funnel 11 by tape weighter 12 is fed on modular conveyor 13. In parallel the granulated powder by spray drying of a composition is received; it is collected in bunker 14 and also is given by tape weighter 15 on conveyor 13. On the same conveyor are dosed sodium perborate from bunker 16 by weighter 17 and enzymes from bunker 18 by weighter 19. All loose components are fed to drum-type mixer 20 where by pumps-weighters 23 and 24 non-ionogenic SAS and aromatizators from reservoirs 21 and 22 are sprayed. The seeming density of received powder is approximately equal to the density of powder, received at spray drying, the size of powder particles are 0,2-1,4 mm.
3.10 Packaging of powders
Packaging of synthetic detergents in cardboard packs is made on automatic-packing lines. Packaging of powder in paper bags (17-20 kg) is made by weighters.
Technological process of packaging and packing of powder on automatic transfer lines includes the following stages: 1) reception of granulated synthetic detergents and their transference on packaging; 2) packaging of powder in packs or bags; 3) packing of packs in parcels or boxes; 4) transportation of parcels and boxes on a warehouse.
Keys: 1, 16, 18 – bunkers for loose raw materials; 2 – weigher; 3 – neutralizer of sulphoacids; 4, 23, 24 – pumps-weighers; 5, 8, 14 – bunkers of ready synthetic detergents powder; 6, 9, 13, 25 – type conveyers; 7 – air lift; 10 – sieve; 11 – funnel; 12, 15, 17, 19 – type weighers; 20 – drum-type amalgamator; 21, 22 – reservoirs of liquid components.
Fig.3.7 – Technological scheme of synthetic detergents production by combined method
Powder by the system of tape conveyors is given to account bunkers of ready product of packaging branch. Preparations of cardboard packs are fed to packaging automatic devices (with help of pendant conveyor). Polyvinilacetate emulsion for pasting from storehouses is fed by pump to account reservoir for introduction of softeners, and then to packaging automatic devices.
Preparations of packs, which have been stuck on longitudinal seam, are loaded in packaging automatic device. From the automatic device packs by means of vacuum capture are entered in transport pockets of scoop conveyor. The conveyor continuously goes. During movement of packs there is formation and sticking up of a bottom, closing of narrow shutters, disclosing of wide shutters and drawing of glue on them. Then the pack comes under weighter funnel and there is filling of pack with a powder. After exit from under funnel there is stirring of powder from shutters of a pack. Stirring is necessary for support of constant level of powder in a pack. The control of level of filling is carried out by light beam, directed under a certain corner inside of a pack. If the level of filling corresponds to established rating value, the reflected beam gets on a photo cell, which blocks the action of the rejection mechanism. The deviation of level of filling from nominal leads to that the reflected light ray does not get on a photo cell, and the rejection mechanism pushes out a pack from a transport pocket. At further moving of a pack there is closing the top narrow shutters, disclosing wide ones, drawing on them of glue and closing.
The stuck packs are fed on completing conveyor, from which by pneumatic pushing out device packs are transferred to conveyor of ready products by parties on 3 or 5 packs. On this conveyor each packs group is turned in thermal-shrinking film. Fixing of packs is made by mechanism of clip, after that falls clamping sponge, heated up to 130-2300С, and occurs the welding and cross-section cutting of a film. Moving of parcels post on mesh conveyor is made due to colliding each of groups by subsequent group.
The moving conveyor transfers blocks of packs through thermal-shrinking furnace, where at temperature 180-2300С there is thermal processing of a film. On exit from furnace the block of packs gets in chamber of cooling, in which packs are blown by air for cooling and stabilization of tension of packs.
Alongside with packing in polyethylene film the packing of packs in cardboard boxes also is carried out. Ready packs from the packaging device on tape conveyor are fed in automatic device of group preparation, where the package of 12 packs is formed and it by pusher moves in box. Filled box goes to the automatic device where there is sticking up.
At packing in bags the powder from account bunkers is fed in automatic weighter. Then the bottom of weighter opens and the powder fills a paper bag up to achievement of the set weight. The filled bags are sewn up by special machine and sent to consumer.
Control questions
Call the basic stages of production of powders by combined method.
Rules of synthetic detergents’ packaging.
4. Cake, paste and liquid detergents production
4.1 Manufacture of cake detergents
Soaps and synthetic detergents in form of bars concern to cake detergents. Soaps are salts of alkylcarbon (fat) acids of natural or synthetic origin. Into structure of synthetic detergents synthetic surface-active substances are entered. Recently cake synthetic detergents in mix with soap are made.
4.2 Cake soap
Plants and alive organisms contain in structure of some tissues complex substances, so-called lipids. The basic part of lipids is fats, i.e. complex ethers of glycerin and fat acids - acilglycerins. Allocated from fats alkyl carbon (fat) acids are surface-active substances, them aliphatic part contains 12-20 carbon atoms. In cake soap sodium alkyl carboxylates are used.
Soap is a mix of 60-80% sodium alkyl carboxylates with water and auxiliary components. The soap is the first industrial product, which began to use for washing and laundering. Soaps are subdivided on toilet and household. The toilet soap contains 80% of salts of fat acids – alkyl carboxylates, and household- 60-70%.
Basic raw material and auxiliary materials for cake soap production
Raw materials for manufacture toilet and laundry soap are various fats, oils and fat-like substances. To them are concerned: technical and food fats, lard mass, coconut, palm-stone, palm and tallow oils, microbe fats, synthetic alkyl carbon and oil acids, rosin, fillers, dyes, aromatic substances and other additives.