CA1120677A - Apparatus for granulating melts of plastics material - Google Patents

Apparatus for granulating melts of plastics material

Info

Publication number
CA1120677A
CA1120677A CA000329215A CA329215A CA1120677A CA 1120677 A CA1120677 A CA 1120677A CA 000329215 A CA000329215 A CA 000329215A CA 329215 A CA329215 A CA 329215A CA 1120677 A CA1120677 A CA 1120677A
Authority
CA
Canada
Prior art keywords
cooling liquid
granulating
granules
chamber
granulating chamber
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
CA000329215A
Other languages
French (fr)
Inventor
Dietmar Anders
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
KraussMaffei Berstorff GmbH
Original Assignee
Hermann Berstorff Maschinenbau GmbH
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Hermann Berstorff Maschinenbau GmbH filed Critical Hermann Berstorff Maschinenbau GmbH
Application granted granted Critical
Publication of CA1120677A publication Critical patent/CA1120677A/en
Expired legal-status Critical Current

Links

Classifications

    • BPERFORMING OPERATIONS; TRANSPORTING
    • B29WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29BPREPARATION OR PRETREATMENT OF THE MATERIAL TO BE SHAPED; MAKING GRANULES OR PREFORMS; RECOVERY OF PLASTICS OR OTHER CONSTITUENTS OF WASTE MATERIAL CONTAINING PLASTICS
    • B29B9/00Making granules
    • B29B9/02Making granules by dividing preformed material
    • B29B9/06Making granules by dividing preformed material in the form of filamentary material, e.g. combined with extrusion
    • B29B9/065Making granules by dividing preformed material in the form of filamentary material, e.g. combined with extrusion under-water, e.g. underwater pelletizers

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Processing And Handling Of Plastics And Other Materials For Molding In General (AREA)
  • Extrusion Moulding Of Plastics Or The Like (AREA)
  • Glanulating (AREA)

Abstract

ABSTRACT OF THE DISCLOSURE:

Granulating apparatus, for plastics melt and other materials comprising an extruder head with a perforated member, a rotating cutter to cut material extruded through the perfo-rated member, a housing surrounding the cutter and forming a granulating chamber with a generally upright axis and liquid supply means to supply cooling liquid to the top edge of the granulating chamber so that the cooling liquid flows in a film over the inner wall of the housing of the granulating chamber to prevent the cut material from sticking to said inner wall and to cool the cut material. The liquid supply means may include a perforated pipe encircling the granulating chamber or a weir at the inner edge of an annular chamber.

Description

llZ~)6'77 The invention relates to apparatus for granulating plastics melt and slmilar materials.
Apparatus for this purpose has been previously pro-posed, comprising an extruder with a perforated member and a rotating cutter disposed coaxially in front of the extruder head, the cutters being surrounded by a granulating chamber which is associated with the extruder head and has cooling liquid flowing through it.
A granulator of this kind is disclosed in German patent specification 1,679,803, which has a water inlet, for cooling the granules chopped off by the blades of the cutter, extending from above, centrally through the extruder head, the water flowing onto a guide which deflects the water radially into the cutting plane. The radial deflection of the centrally introduced cooling water cannot prevent the cooling water from coming into contact with the perforated plate, causing the plate to be cooled and the plastics to stick to it. When cooling water comes into contact with the perforated plate there is a so called "frosting over" of the plate, that is to ~0 say, the holes become clogged with the cooled and solidifying plastics.
It has been proposed in German patent specification 1,45~,888 to force a cooling liquid against gravity into an annular, horizontally arranged granulator housing, in order to cover an annular inner shell of the granulator housing with a film of water. If a thick enough film of water is to be obtained on the inside of the housing, the cooling liquid has to be forced into the granulator housing against gravity at a high pressure. This involves considerable expenditure on energy and in addition can only be applied to granulators with a relatively small output.

As a means of avoiding these disadvantages, it has ~'4 - 1- ~

llZ0677 been proposed in German patent specification 2,035,035 that a horizontally disposed, cylindrical granulator housing should be rotatable about its longitudinal axis, so that less pressure and thus lower energy costs are required to produce the film of cooling water on the inner wall of the housing to carry away the granules and prevent them from caking. Extra costs are incurred through the additional drive for rotating the housing.
However, the greatest disadvantage is that with this construction too the cooling water comes in-to contact with the perforated plate of the extruder head, leading to frosting of the plate and thus total stoppages of the operation.
The invention has among its objects to provide a granulator which can give a very high output and in which there will be no agglomeration of the granules chopped off.
A further object is to ensure that the perforated plate does not frost over and thus become clogged by cooling, and that the operative state of the granulator is monitored and maintained.
According to the invention, as herein broadly claimed, there is provided an apparatus for granulating plastics melt and similar materials, comprising: an extruder head through ,~ot~` /
which material to be extruded is passed, a ~ cutter dis-~ 7~ t~vcle 1~posed in front of said e~ head for cutting said plastics material into granules, a housing surrounding said cutter and including an outer shell and a spaced, cylindrical inner shell which forms a granulating chamber, said inner shell being smaller in diameter than said outer shell thereby to form an annular chamber open at its upper end between said shells, and being smaller in height than said outer shell thereby to form a weir extending around said granulating chamber at the upper end thereof; cooling liquid supply means communicating with said annular chamber for supplying cooling liquid thereto, and ~.

~ ~'Z0677 outlet means in said granulating chamber for removing there-from the cooled granules and cooling liquid, whereby cooling liquid admitted to said annular chamber between said outer and inner shells can be directed into said granulating chamber over said weir to form a film over the inner surface of said inner shell, said granules thus formed contacting said film of cooling liquid to cool said granules and prevent said granules from sticking together, said film constituting the sole means of coolant contact for said granules.
In one example, the cooling liquid is fed into an annular .

~ _ r~

chamber formed between the outer wall of the housing and a cylin-drical inner shell of the ~ranulatin~ chambcr. Ilere the cooling liquid rises until it pours o~er a woir at the top edge of the inner shell and covers it with a film of cooling liquid. If material is being granulated into this chamber the granules, which have a radial motion imparted to them by the cutter, will land on the inner shell covered with the film of cooling liquid, and will thus be conveyed to the bottom of the granulatin~ chamber, from which they will emerge through an outlet.
Since the quantity of cooling liquid fed into the annular chamber between the inner and outer shells of the granulating hous-ing can be increased at will, the granulator can be adapted to al-most any output; as the speed at which the film of liquid flbws over the inner shell is increased, more granules are carried away, without any individual granules touching one another and thus sticking together as they strike the film.
As a means of ensurin~ that the cooling liquid introduced into the granulating housing, when fed through the annular cavity, will pour over the top edge of the inner shell with an even speed of flow and will wet ~he inside of the shell with a layer of li~uid of even thic1tness, resistance elements to eq~lalise the flow are pro-vided in the anmtlar chamber between the inner shell and the outer housing, in the form of an annular plate with rows of holes therein.
These prevent any eddies from formin~ in the annular chamber a~d ensure that the coolin~ medium pours evenly over the top of the inner shell.
Preferably the fl~w of cooling liquid out of the s~pply means provided for the purpose at the top edge of the granulator housing is monitored, to ensure that there is always a film of liquid on the inner face of the housing. For this pltrpose sensing ~cans of kno~ kind is provided in the immediate vicinity of the means dis-charging the coolin~ liquid. ~en there is a lack of cooling liquid the sensing means acts through control means to switch o~f the granulator and/or cxtruder, thercby effectively preventing the inner 3~ wall from becoming caked with plasticsO
The outflow of cooling liquid with the chopped up granules ~ Z0677 can be monitored by an outlet sensing means, which ensures that the granulator and/or extruder is switched off if the outflow p;.pe should become bloclsed.
The invention is dia~rarmatically illustrated by way of 5 example in the accompanying drawings, in which:-Figure 1 shows a first embodiment of granulating apparatus according to the invention with a multiple-walled granulating chamber; and Figure 2 shows a second embodiment of ~ranulating apparatus ~0 according to the invention with a single-walled granulating chamber.
Referring to the drawings and firstly to Figure 1, plastics material is convoyed into a deflecting extruder head 3 from an extruder 1 having a worm 2. The head 3 has a perforated disc (not shown) at its underside, with cutters 4 running directly across it. The rutters 4 are held by a support 5 mounted on a cutter shaft 6. The shaft 6 passes through the deflectin~ head 3 and is driven by a motor 7. A coolin~ liquid is supplied to a granulator hausing 9 through an inlet 8. The housing 9 comprises an outer shell 11 and an inner shell 1.0, the inner shell being disposed within the outer shell li. and defining a ~ranulating chamber 12.
The inner shell 10 is smaller in diameter than the outer shell 11 and open at the top, so that the coolin~ uid which enters through the inlet ~ pours over a weir formed by the upper ed~e of the inner shell 10 as indicated at ~7 nnd thu3 forms a film of cooling liquid. on the inside of the inner shell 10.
The plastics which is conveyed into the deflccting head 3 by the worm 2 of the oxtrude. 1 passes through a system of dis-tributin~ p~ssa~es (not shown) to the perforated disc (not shown~, throu~h which it is extrudod in strand fcrm. Immodiately on leaving the perforated ai sc the strands are chopped into granules by the revolving cutters 4. The paths of travel of the individual ~ramlles from the perforate/l di.sc to the film of water on the inner shell ~0 do not interscct, and the overflowing coolant which forms the fil of liquid, preferably water, rapidly carries away -the granules to , , .. , . . ... . . .. . . , .... ., . .. .... ~

i ZC~6~7 a coolant outlet 15. Individual granulnr particles are thus pre-vented from clinging together.
The construction illustrated has the particular advantage that the coolant, which is necessary to cool the granules and which prevents the individual particles from cal~ing, does not come into contact with the perforated disc from ~ich the individual strands are emerging. This is an efiective way of preventing the pérforated disc from being cooled by the cooling liquid and the plastics, which is curëd by the cooling liquid, from being deposited in the holcs, which would lead to clogging and total breal~do~n of the granulating function.
Resistance elements 18, 19 to equalise the flow are located in the annular chamber 16. They may each, ~or example, have rows of holes in a horizontally disposed annular plate.
Pneumatic cylinders 23 cooperating with rods and levers 22 may be provided to adjust the relative position of the granulating chamber 9 and the extruder head.
~ eferring to Figure 2, a sin~le-walled granulating housing 109 has a pipe 117 disposed at its upper edge and extending around its periphery, with apertures (not shown) formed in the pipe and dirccted towards the inner face of a wall 110 of the housing 109.
Coolant passes through an inlet pipe 108 into the annular pipe 117 and runs through said apertures and do~ the inner face of the wall 110 of the granulating housing 109.
The material to be granulated is conveyed into a deflecting head 103 by an extruder 101 having a worm 102, and leaves the head 103 througn an annular disc (not sho~n) uith rows of holes formed in it. Immediately after the strands energe from the rows of holes they are chopped into individual granules by rota-ting cutters 104, which are drivcn by a motor 107 by way of a shaft I06. The cutters 104 impart a radially outward movement to the granules, so that they impinge on a film of water rulming down the inner face of the wall 110. The uater conveys the granules to a coolant outlet 115 disposed at the bottom of the housing 109.
In thc immediate vicinity of the pipe 117 discharging the coolnnt, or of the ~cir fo~ned by the overflow edge 17 of the inr3er ~lZID677' shell in the embodiment of Fi~ure 1, there is a sensing ~eans 120 or 20 respectively to monitor the flow of coolin~ water. This switches off the granulator or the extruder 1, 101 by means of a control device (not shown), should the supply of coolant bc inter-rupted or should the thickness of the film of coolant drop belowa predeter~ined limit, thereby preventing the granules being chopped off from lnnding on and sticking to parts of the granulr.tor which are not wetted with cooling water.
~ An additional sensing means 21 or 121 indicates when the coolant outflow pipe 15, 115 is blocked. When the level of cooling water in the granulating chamber 12, 112 rises beyond an admissible level, the sensing ~eans 2i, 121 acts through control devices (not shovn) to switch off the granulator or the extruder 1. This avoids having the whole granulating function put into question by blochage of the coolant outlet 15, 115.
The bousing o~ the granulator 9, iO9 illustrated in the ~rawings is cylindrical. ~owever, the granulntor housing could be rectangular, hexngonal or of other form if desired.

Claims (5)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:
1. Apparatus for granulating plastics melt and similar materials, comprising:
a) an extruder head through which material to be extruded is passed, b) a rotary cutter disposed in front of said extruder head for cutting said plastics material into granules, c) a housing surrounding said cutter and including an outer shell and a spaced, cylindrical inner shell which forms a granulating chamber, said inner shell being smaller in diameter than said outer shell thereby to form an annular chamber open at its upper end between said shells, and being smaller in height than said outer shell thereby to form a weir extending around said granulating chamber at the upper end thereof;
d) cooling liquid supply means communicating with said annular chamber for supplying cooling liquid thereto, and e) outlet means in said granulating chamber for removing therefrom the cooled granules and cooling liquid, whereby cooling liquid admitted to said annular chamber between said outer and inner shells can be directed into said granulating chamber over said weir to form a film over the inner surface of said inner shell, said granules thus formed contacting said film of cooling liquid to cool said granules and prevent said granules from sticking together, said film constituting the sole means of coolant contact for said granules.
2. The apparatus of claim 1 further including resistance means in said annular chamber to equalize the flow of cooling liquid over said weir, said resistance means com-prising an annular plate formed with openings upwardly through which said cooling liquid passes.
3. The apparatus of claims 1 or 2 further including means for vertically moving said granulating chamber relative to said extruder head.
4. The apparatus of claim 1 or 2, further including sensing means to monitor the outflow of cooling liquid and disposed in the immediate vicinity of said cooling liquid supply means, said sensing means acting through control means to switch off the apparatus if it senses a lack of cooling liquid.
5. The apparatus of claim 1 or 2, further including outlet sensing means to monitor outflow of granulated material and cooling liquid from said granulating chamber, said outlet sensing means, if activated, acting through control means to switch off said apparatus.
CA000329215A 1978-06-09 1979-06-06 Apparatus for granulating melts of plastics material Expired CA1120677A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DEP2825287.1 1978-06-09
DE19782825287 DE2825287A1 (en) 1978-06-09 1978-06-09 DEVICE FOR GRANULATING PLASTIC MELT

Publications (1)

Publication Number Publication Date
CA1120677A true CA1120677A (en) 1982-03-30

Family

ID=6041400

Family Applications (1)

Application Number Title Priority Date Filing Date
CA000329215A Expired CA1120677A (en) 1978-06-09 1979-06-06 Apparatus for granulating melts of plastics material

Country Status (8)

Country Link
JP (1) JPS54161665A (en)
CA (1) CA1120677A (en)
DE (1) DE2825287A1 (en)
FR (1) FR2427892A1 (en)
GB (1) GB2022504B (en)
IT (1) IT7921745V0 (en)
NL (1) NL7904483A (en)
SU (1) SU837312A3 (en)

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS61185416A (en) * 1985-02-13 1986-08-19 Japan Steel Works Ltd:The Vertical type apparatus for producing particles in air
JPS62199408A (en) * 1986-02-27 1987-09-03 Kasamatsu Kako Kenkyusho:Kk Method and apparatus for preparing synthetic resin pellet
JPH0264011U (en) * 1988-11-01 1990-05-14
WO1992018311A1 (en) * 1991-04-10 1992-10-29 Masao Moriyama Apparatus for manufacturing plastic pellets
AT508199B1 (en) * 2008-12-16 2011-05-15 Erema DEVICE FOR HOT SPILL GRANULATION
CN114619593A (en) * 2022-03-11 2022-06-14 长江师范学院 Device and process for preparing polyethylene glycol terephthalate

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1221783B (en) * 1959-10-16 1966-07-28 Buss Ag Collecting housing for granulating machines
NL6500527A (en) * 1964-02-01 1965-08-02
LU48129A1 (en) * 1964-03-24 1965-05-05
JPS497583B1 (en) * 1964-06-18 1974-02-21
GB1382701A (en) * 1971-04-02 1975-02-05 Welding Engineers Face cutting apparatus for forming pellets

Also Published As

Publication number Publication date
FR2427892A1 (en) 1980-01-04
DE2825287A1 (en) 1979-12-13
NL7904483A (en) 1979-12-11
SU837312A3 (en) 1981-06-07
GB2022504A (en) 1979-12-19
IT7921745V0 (en) 1979-06-06
GB2022504B (en) 1982-08-04
JPS54161665A (en) 1979-12-21

Similar Documents

Publication Publication Date Title
US4245972A (en) Granulating apparatus
US3341892A (en) Pelletizing apparatus
US6592350B1 (en) Underwater pelletizer with separator
US3867082A (en) A granulating device for granulating synthetic plastics material in a flowable stage
KR100647253B1 (en) Underwater Pelletizer
US4321026A (en) Device for granulating plastic strands
US3029466A (en) Liquid phase pelleter
US5143673A (en) Process and apparatus for underwater granulation of molten thermoplastic material particularly during start-up periods
US20160193771A1 (en) Method for producing superficially crystalline spherical granules by means of air-cooled hot die face pelletizing and apparatus for carrying out the method
US3415917A (en) Process for forming and cooling thermoplastic resin pellets
CA1120677A (en) Apparatus for granulating melts of plastics material
US4097212A (en) Pelletizer
US3333298A (en) Granulating machines
US4838775A (en) Device for granulating strands of thermoplastic materials
KR100836242B1 (en) Device for granulating a thermoplastic, which is extruded from nozzles
TWI578981B (en) Method for production of pharmaceutical products from a molten material
US4663099A (en) Method and apparatus for producing separate unagglomerated pellets of an extrudable material
US4401421A (en) Apparatus for granulating plastics material or plastic compositions
JPH06155455A (en) Granulating device of thermoplastic resin
US4385884A (en) Granulation chamber for plastics materials
US20160279829A1 (en) Apparatus and process for granulating molten material
US3358323A (en) Processing of plastic
JPS61185416A (en) Vertical type apparatus for producing particles in air
JP2591671B2 (en) Apparatus for producing spherical particles of oily substance using organic solution as refrigerant
US3114170A (en) Extrusion device

Legal Events

Date Code Title Description
MKEX Expiry