GB1588172A

GB1588172A - Milling mixing or dispensing apparatus

Info

Publication number: GB1588172A
Application number: GB41436/77A
Authority: GB
Original assignee: EIGER ENG
Current assignee: EIGER ENG
Priority date: 1977-10-05
Filing date: 1977-10-05
Publication date: 1981-04-15
Also published as: BE871050A; CH635523A5; DE2843501C2; DE2843501A1

Abstract

The grinding device has a grinding chamber which is enclosed by a housing (8) and in which a grinding body charge of spheres or other components and means (9) for agitating this grinding body charge are arranged. These agitating means are driven by a motor (1) whose shaft (6) protrudes into the housing (8) of the grinding chamber. The motor housing (3) and the housing (8) of the grinding chamber form a single, uniform structure. <IMAGE>

Description

(54) IMPROVED MILLING, MIXING OR DISPENSING APPARATUS (71) We, EIGER ENGINEERING LIMITED, a British Company of 19 Greenhill Parade, New Barnet, Hertfordshire, do hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to apparatus for milling, grinding, mixing, dispersing, emulsifying, homogenising and similar functions hereinafter referred to as milling apparatus of the kind specified. Apparatus of the kind specified comprises a milling chamber for containing particulate material such as granules or beads hereinafter termed the grinding charge and agitating means for submitting this grinding charge and material to be milled or otherwise treated within the chamber to intense agitating and shearing forces. These means typically comprise rotating impellors such as discs and paddles. In use the material to be milled is caused to flow through the milling chamber and to be submitted to the intense agitation and shearing forces in admixture with the particulate material. Such apparatus are conventionally referred to as "sand mills" or "agitated bead mills" depending on the nature of the particulate material and or the manufacturers preference.

According to the present invention there is provided apparatus of the kind specified comprising a motor in a casing and milling means in a housing wherein the motor casing and milling means housing form a single integrated structure and wherein the milling means comprises a shaft carrying agitating means and formed as an extension of the main shaft of the motor.

The motor is preferably an electric motor.

Inlet and outlet ports for material to be milled are provided in the housing. Preferably the material enters through a port in the housing wall periphery adjacent the electric motor and leaves milled through the end wall of the housing remote from the motor though a reverse flow direction could be arranged. The exit port for milled material is preferably partially closed by a sieve or other means such as slits preventing the escape of the grinding charge.

When the motor casing includes an end flange the milling housing can be fixed to the flange either directly or through the intermediary of a spacer such as a seal around the shaft.

In one embodiment of the invention a milling means in its housing is provided at each end of the motor casing, the motor shaft being extended into each housing.

A particular embodiment of the invention will now be described by way of example and with reference to the drawing which accompanied the Provisional Specification and which shows a milling apparatus with the milling housing thereof in section.

The milling apparatus shown therein comprises an electric motor 1 mounted for use in the vertical orientation with one end secured to a mounting plate 2. The internal construction and mechanism of the motor within its casing 3 does not form part of the present invention and will not be described. It should be noted, however, that the motor has at one end a fixing flange 4 of circular form with an upwardly directed locating annular rim 5.

In accordance with the present invention the main shaft 6 (not shown in section) of the motor 1 extends upwardly into a milling chamber 7. Region 6(a) is a shouldered portion of the shaft 6; region 6(b) is a keyway and 6(c) is a threaded nut holding impellors 9 and spacers 9(a) in position. The milling chamber 7 is contained in a cylindrical housing 8 forming a coaxial extension of the motor casing 3 thereby providing a compact and convenient integrated unit readily vertically mountable as illustrated but also securable in other orientations if so desired.

The shaft 6 carries impelling discs 9. The housing has an inlet port 10 for the product to be milled positioned in the housing peripheral wall 8 adjacent the motor flange 4 and exit port 11 for the milled product in the upper end surface of the housing 22. The housing peripheral wall is surrounded by a cooling jacket 12 having inlet and outlet ports 13 and 14 respectively for cooling water.

A lower plate or connecting piece 15 closing the milling chamber is attached to the motor flange 4 by screws 16 and has an annular recess 17 engaging rim 5 and the milling chamber is attached to the motor flange by screws 16a. A cylindrical stem 18 with lid 18a provides a seal housing 19 for an appropriate shaft seal (not shown). Drillings may be provided in plate 15 to allow liquid flushing of the scal. A sieve 20 covers the mouth of an annular recess 21 on the upper end plate 22. the product outlet port 11 being located at the roof of the recess or alternatively the sieve may be used to cover an annular recess in plate 15 wherein the product would enter through port 11 and out through a port provided behind the sieve in plate 15.

In use the chamber is partially filled using known technology with a grinding charge of particulate material having a diameter of between 0.1 mm to 5 mm and the product and water caused to flow through the appropriate inlet and outlet ports. The motor is operated to rotate shaft 6 thereby causing impellor discs 9 to develop the appropriate intense agitation and shearing conditions within the milling chamber 7. The escape of the grinding charge is prevented by sieve 20.

The milling apparatus described above has several constructional advantages arising from forming the milling chamber integrally with the motor casing and using as the impellor drive the coaxial extension of the motor shaft. Specifically conventional drive transmission elements such as belts chains. gearings and secondarv shafts and bearings are avoided and the possibility of orientating the device verticallv. as illustrated. means that. in the starting condition with the grinding charge at rest when the greatest strain is placed on the motor.

that strain is presented to the shaft immediatelv as it emerges from the motor housing rather than at a remote point. A further advantage of vertical orientation is that the top plate 22 can readily be removed for filling with the grinding charge and inspection and. if necessary.

replacement of the sieve 20.

Typical speeds in commerciallv available motors are approximately three thousand.

fifteen hundred. a thousand and seven hundred and fiftv r.p.m. Mills of this tvpe operate efficientlv with agitator peripheral speeds between ten and twenty metres per second although for very viscous materials lower speeds may be required which can be arranged either bv reducing agitator diameter configuration or by choosing a slower motor speed.

A range of mill sizes with good relative dimensions is set out in the following Example.

EXAMPLE Production Models Laboratorv Model Small Medium Large Motor speed (rpm) 3()() 1500 1000 750 Chamber volume (litres) 1 10 A() 150 Agitator diameter for peripheral speed of 14 m/sec. mm mlll 178 mm 267 mm 357 mm Chambel diameter (mm) l l() 210 3 It) 4 Chamber length (mm) I It) 420 69() l 1100 Motor Horse Power 2 10 3() 75 Motor diameter (mum) 2()() 30() A()() 550 WHAT WE CLAIM 1S: 1. Apparatus of the kind specified comprising a motor in a casing and milling means in a housing wherein the motor casing and milling means housing form a single integrated structure and wherein the milline means comprises a shaft can!iin! agitating means and formed as an extension of the main shaft of the motor.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **.

The shaft 6 carries impelling discs 9. The housing has an inlet port 10 for the product to be milled positioned in the housing peripheral wall 8 adjacent the motor flange 4 and exit port 11 for the milled product in the upper end surface of the housing 22. The housing peripheral wall is surrounded by a cooling jacket 12 having inlet and outlet ports 13 and 14 respectively for cooling water.

A lower plate or connecting piece 15 closing the milling chamber is attached to the motor flange 4 by screws 16 and has an annular recess 17 engaging rim 5 and the milling chamber is attached to the motor flange by screws 16a. A cylindrical stem 18 with lid 18a provides a seal housing 19 for an appropriate shaft seal (not shown). Drillings may be provided in plate 15 to allow liquid flushing of the scal. A sieve 20 covers the mouth of an annular recess 21 on the upper end plate 22. the product outlet port 11 being located at the roof of the recess or alternatively the sieve may be used to cover an annular recess in plate 15 wherein the product would enter through port 11 and out through a port provided behind the sieve in plate 15.

In use the chamber is partially filled using known technology with a grinding charge of particulate material having a diameter of between 0.1 mm to 5 mm and the product and water caused to flow through the appropriate inlet and outlet ports. The motor is operated to rotate shaft 6 thereby causing impellor discs 9 to develop the appropriate intense agitation and shearing conditions within the milling chamber 7. The escape of the grinding charge is prevented by sieve 20.

The milling apparatus described above has several constructional advantages arising from forming the milling chamber integrally with the motor casing and using as the impellor drive the coaxial extension of the motor shaft. Specifically conventional drive transmission elements such as belts chains. gearings and secondarv shafts and bearings are avoided and the possibility of orientating the device verticallv. as illustrated. means that. in the starting condition with the grinding charge at rest when the greatest strain is placed on the motor.

that strain is presented to the shaft immediatelv as it emerges from the motor housing rather than at a remote point. A further advantage of vertical orientation is that the top plate 22 can readily be removed for filling with the grinding charge and inspection and. if necessary.

replacement of the sieve 20.

Typical speeds in commerciallv available motors are approximately three thousand.

fifteen hundred. a thousand and seven hundred and fiftv r.p.m. Mills of this tvpe operate efficientlv with agitator peripheral speeds between ten and twenty metres per second although for very viscous materials lower speeds may be required which can be arranged either bv reducing agitator diameter configuration or by choosing a slower motor speed.

A range of mill sizes with good relative dimensions is set out in the following Example.

EXAMPLE Production Models Laboratorv Model Small Medium Large Motor speed (rpm) 3()() 1500 1000 750 Chamber volume (litres) 1 10 A() 150 Agitator diameter for peripheral speed of 14 m/sec. mm mlll 178 mm 267 mm 357 mm Chambel diameter (mm) l l() 210 3 It) 4 Chamber length (mm) I It) 420 69() l 1100 Motor Horse Power 2 10 3() 75 Motor diameter (mum) 2()() 30() A()() 550 WHAT WE CLAIM 1S: 1. Apparatus of the kind specified comprising a motor in a casing and milling means in a housing wherein the motor casing and milling means housing form a single integrated structure and wherein the milline means comprises a shaft can!iin! agitating means and formed as an extension of the main shaft of the motor.
2. Apparatus as claimed in Claim 1 wherein the motor is an electric motor.
3. Apparatus as claimed in either Claim 1 or Claim 2 wherein the motor main shaft is extended into the milling means housing.
4. Apparatus as claimed in any of the preceding claims wherein the motor has a generally symmetrical, for example. a cylindrical casing with the main shaft extending along the longitudinal axis thereof and the housing for the milling means extends coaxially from the said casing.
5. Apparatus as claimed in any of the preceding claims wherein the motor casing has an end flange and the milling means housing is bolted to the said flange either directly or through the intermediary of a spacer.
6. Apparatus as claimed in Claim 5 wherein the spacer is a housing for a seal around the said shaft.
7. Apparatus as claimed in any of the preceding claims wherein an inlet for material to be milled is formed in the peripheral wall of the housing adjacent the motor casing and an outlet for milled material covered by means for preventing the escape of the grinding charge is formed in the end face of the casing remote from the motor.
8. Apparatus as claimed in Claim 6 wherein an inlet for material to be milled is formed in the peripheral wall of the housing adjacent the motor casing and an outlet for milled material covered by means for preventing the escape of the grinding charge is formed in the end face of the casing remote from the motor.
9. Apparatus as claimed in either Claim 7 or Claim 8 wherein the means for preventing the escape of the grinding charge is a sieve.
10. Apparatus as claimed in any of the preceding claims wherein a milling means in its housing is provided at each end of the motor casing. the motor shaft being extended into each housing.
11. Apparatus substantially as shown in the drawing accompanying the Provisional Specification.
12. Apparatus substantially as described with reference to the Example.
13. A method of milling or similarly processing which comprises passing material through the milling means of apparatus as claimed in any of the preceding claims.