SE190874C1 - - Google Patents

Description

Inventors: H F Zinc, W C Taylor and C D Pawlicki The accompanying drawings and description are ascondylating and describe a device and a salt for forming calcium silicate material, such as pipe insulation, core blocks, etc.

The molded insulation or other materials referred to are preferably prepared from aqueous slurries of fire lime and silicic acid, in which the molar ratio of lime to silicic acid may be in the range of 0.65: 1 to 1: 1 and the weight ratio of water to silicon. solids may be at least 0.75: 1. However, other reactive agents or materials, such as magnesia, etc., may also be used according to this salt and this device.

The suitable density for pipe insulation Or about 0.167 g / cm3 but the intention Or Above, that other products Mom other density ranges should be manufactured for specific purposes and uses. The suspension of the solid substances in the liquid slurry is formed dangerously with the aid of highly fluffy or prickly asbestos fibers, but other suspending and / or dispersing agents can be used, such as bentonite, powdered aluminum, etc.

In the present case, it is appropriate to use a water-based slurry, mainly consisting of fire lime, silicic acid, asbestos fibers and water as starting material, whereby in such a slurry the weight ratio between water and solids Iran may initially be a comrade of 0.75. : 1 to about 7: 1 depending on the desired density of the integrated end product.

The invention makes it possible to use commercially available common slurries for the manufacture of a normal commodity, whereby a reduced number of molds taken up over a long period of time and end products are obtained which have a dimensional stability which is better than that which can be achieved according to any current method. .

The set and apparatus according to the invention are based on a principle according to which calcium silicate products within a relatively short time by treatment in a mold can be dyed in a state in which they can be removed from the mold in a self-sustaining condition. As a result, a short forming process can be applied and the mold quickly cleaned. Large quantities of molded molds can thus be manufactured with a very small number of molds.

The accompanying drawings schematically show, by way of example, a device for carrying out the air set according to the present invention. Fig. 1 shows a vertical cross section through a mold unit. Fig. 2 Or a cross section along the line in Fig. 1.

Fig. 3 is a diagram showing the relationship between the different steps in a forming cycle, Fig. 4-7 is a schematic representation of the order of the different steps.

It should be noted that air or liquid pressure on the slurry does not in itself necessarily mean that the slurry is cooled, but this serves to prevent a rapid release of air or water from the slurry when the external steam heating is interrupted. The invention relates primarily to: 11. primarily manufacturing air-reacted or hardened materials in the form of pipe insulation, but it is of course also intended that the same method and apparatus can be used to manufacture other shaped products, such as non-magnetic cores for electrical devices and the like. roofing, etc.

The production of pipe insulation in a cylindrical shape necessarily requires, when starting from an aqueous slurry, that the mold is in a vertical position and the pipe is cast on this sail. Salunda Or a cylindrical shape either interchangeably arranged or permanently Dupl. at 12 g: 2/01; 80 a: 9/05; 80 b: 1/07; 80 b: 1/08; 80 b: 1/09; 80 b: 18/07 2 --- - built into a cylindrical hardening device in such a way that a steam heating jacket for heating the cylindrical shape rocks Midas. The upper part of the hardening device is closed, whereby an upper closure of the steam jacket around the mold is obtained, whereby, however, the top or filling opening in the mold is left open in order to expose the surface of the slurry which is inserted therein. Above this open spirit on the mold and above the steam jacket, but insulated and separate from said steam jacket, a lid is applied, which is so shaped and recessed that a chamber is formed over the top of the mold, which thanks the filling opening in the mold.

Such a construction dilates, that the temperature conditions in the ang mantle resp. the chamber can be controlled individually, which is a design feature which is essential for obtaining and allowing some rapid temperature drop in the pre-cured molded product from a temperature above 1000 DEG C. down to about room temperature without cooling or enlarging the molded product.

The speed of this temperature change is very important, as it is one of the essential points in the operating process, and when combined with a partial overlap of the processing steps in the treatment, it dilates a very short and fast operating cycle. In order to support and enable a very fast operating cycle, the slurry is preheated in a mixer by using steam condensate with regulated pressure (4.2 kp / cm2) for a certain time. The radiating anxiety pressure, the amount of slurry that is mixed, and the desired temperature of the sludge determine the time. for the pre-confirmation.

The particular mixture used, of course, affects or otherwise affects the optimum temperature range for pre-fermentation, but in most cases the temperature ranges from 66 ° to 77 ° C. However, there may be mixtures in which the material, such as coarse silica, Temperatures require a higher range, but in no case will such a temperature exceed 100 ° C or the boiling point of the water at atmospheric pressure.

By heating the slurry in a mixer, ie. outside the mold, the material is given the opportunity to expand freely and the reaction begins, before the material is enclosed in the mold, whereby any further expansion in the further reaction in the mold only takes place in one direction, ie. the longitudinal shape of the mold. When the preheated slurry is introduced into the mold, the material will assume a solid state more quickly (transfer to a solid phase), the thermal expansion in the mold will decrease and the movement of the material, while it transitions to a solid state, will be reduced to such an extent that it separation in a horizontal plane is prevented, which would otherwise occur.

By filling the preheated mold with this preheated slurry, the reaction started in the mixer continues continuously in the mold: without flake nominal difference: d between the reaction rate in different layers of the material. Thus, the rate of progress of the reaction is approximately constant from the time of the initial mixing until the desired degree of reaction is reached.

In addition, the temperature differences which could occur within the mass and in particular in different layers thereof are reduced to a minimum, and as a result any possibility of movement within the mass is likewise reduced to a minimum.

Such preheating gives the advantage that the required heating time in the mold is reduced, and this is especially the case, but such a slurry is introduced into an already preheated mold, which immediately mediates a state where differences in thermal expansion in different layers of the material are avoided. mainly due to the absence of severe temperature differences between different layers in the material.

Fig. 1 shows an embodiment of a mechanical device in a molding mechanism, by means of which the set according to the invention can be made, and in which a mold for molding one of the many sizes of outer diameter, which is required in the size series of made rorisoleringer. Said mold can be exchanged in its own hardening device 11. The upper spirit of the mold 10 is arranged so that it forms a closure 12 with the upper spirit of the hardening device 11 and also forms a flat, upper surface 12a, from which any excess slurry can be easily removed. The bottom part of the cylindrical mold 10 fits on a shoulder 13, which is formed by the bottom plate 14 of the mold. The mold 10 and the curing device 11 are challenged and assembled so that there is a chamber 15 between them into which steam, water or other heating or cooling media can be introduced under pressure or otherwise. A series of roots. 20 on a manifold 21 are arranged to supply means for heating the cylindrical cradle portions of the mold 10. A similar arrangement of tubes 23 on a manifold tube 24 tiff & coolant at the intended time intervals. A drain system for the chamber 15 consists at least of a vertical Dar 25, which is open at its opening, and a further down, open pipe 26, which is connected to the drain line 27, and a control valve 28. A piston 30 is below a part of the process coated in the bottom of the mold 10 and arranged to be moved up and down in it by means of rods 31 and 32, a double-acting transmission and rack mechanism and an air motor 33. Naminda piston 30 Or provided - —3 with flexible or resilient piston rings 35 and 36 .

The rods 31 and 32 are arranged at their lower ends on a crosspiece 40, the ninth crosspiece on one side carrying a vertically arranged rack 11. On the opposite side but flush with the rack 41 is a second vertical, fixed rack 42 mounted on a vertical bracket 43, which extends down the Iran stand 38 for the hardener. Between the said racks 41 and 42 a gear 44 is arranged, which engages with both racks. Each vertical movement of the gear 44 in relation to the rack 42 entails that the rack 41 moves in the same direction as the gear, but a longer distance. Thus, with the construction shown, in a movement of the gear 44, a movement of the rack 41, the crosspiece 40, the rods 31 and 32 and the piston 30 connected thereto, so that a shaped piece of material is protruded or expressed from the mold 10 and in the opposite stroke direction absorbs slurry in the mold and fills it.

A man 45, depicted e.g. of a tube without a joint and closed at its upper spirit, extends upwards through the bottom 14 of the mold along the vertical centerline of the mold 10 and is supported in such a position at its bottom by means of a bracket 46, which is attached to a vertical support 47. The core 45 is so formed , to indicate that water or other heating or cooling media can be introduced into its Owe spirit through the conduit 48 so as to thereby heat or cool the inner surface of the slurry which is in contact therewith when the sludge is formed. Such heating and / or cooling media can be introduced through lines 50 and 50, respectively. 65 and is regulated by valves 61 ocb. 75. A control valve 49 in the line 50 prevents any return of the coolant to the main line 50. The walla media is drained through the line 52 and the control valve 53. A lid 55 is releasably mounted on the hardening device 11 on the edge set, e.g. by means of a bayonet socket 58. A partition 56 is arranged below the chamber 57 and is so coated that it serves as a spreading disc for spreading compressed air or other media, as these are introduced into this space, and to prevent the direct effect thereof on the slurry in the mold. The mold 10, bottom 14, piston 30 and core 45 are all interchangeable to allow the production of materials of different diameters and thicknesses.

The heating and cooling media are let in and out of the chambers 15 and 57 saint karnan 45 on the following salt. A main line 60 is connected to a suitable pressure range from about 1.05 kp / cm2 to about 1.40 kp / cm2 (gauge pressure) to a control valve 61, which, when it is open, enters the chamber. 15 and in the core 45 through the conduit 48. When the valve 61 is open, currents hang under pressure through the conduit 62 to the manifold 21 (Fig. 2) and then to a series of vertical outlets 20 within the chamber 15. These outlets 20 are . arranged, that they direct the angan pa sa. provided that the steam does not directly hit the cradles of the mold 10, thereby avoiding local heating.

A main line 65 for the water to & water under pressure to a container 66 and to other points for final use in the system. The supply lines 67, 68 feed the frail tank 66 to the chamber 57, and a control valve 69 controls the water supply to the chamber 57. A flexible hose 70 forms part of this line to allow inability to remove the lid 55 when required. A valve 71, which is normally closed, regulates the discharge from the chamber 57 at appropriate intervals.

The main pipe 65 for the water, which is also connected to the pipe 45, has devices for regulating the water supply to the pipe 45 by means of the valve 75 and for supplying water to the chamber 15 through the pipes 23 and the manifold 24 by means of the regulating valve 76. The valves 75 and 76 are arranged. to be opened and closed at the same time so that the chamber 15 and the core 45 are to be cooled simultaneously, which is not apparent from the drawing. The valves 28 and 58 are intended to be simultaneously opened and closed to obtain good control of the aeration of the chamber 15, and the hollow core 45 during the heating and cooling operations.

An air duct 80 supplies air under a pressure of about 2.1 kp / cm2 to the container 66 under the control of the valve 81, whereby air-matte water or matte liquid can be supplied to the chamber 57 at the desired time. The purpose of combining air and water under pressure is to provide a medium under pressure over the surface of the slurry, which prevents dehydration of the slurry and any possibility of boiling due to the rapid temperature changes which take place during the process. Another air line 85 extends from the air main line 80 and leads to a reversing valve 86, which is intended to alternatively feed air to opposite spirits on the cylinder 33 to set the piston in motion and thereby alternatively fill the mold 10 and express the shaped product therefrom.

The opening and closing of all these different valves, which are not in the operation of this device, can be controlled and timed in order to perform the desired operating cycle by means of known devices (not shown), and these valves can be driven or actuated by air motors or solenoids. alit as desired. A series of these mold units can be arranged in a circle, in a straight line or otherwise, and can also be joined together so that they work in succession, with the aid of a time installation device.

- - The operation of each individual mold unit is schematically indicated in Fig. 3 and takes place as follows.

In delta diagrams, the steps of the cycle are shown in a possible time relationship with respect to each other and to the movements of the filling and expressing piston 30, da. all these steps in the course of operation are dependent on the movements of said piston. After the ay closure cap 55, as shown at a, is removed, the piston 30, as indicated at b, moves to its lower layer A and pushes out the previously formed charge. The dashed line in Fig. 3 shows the relative position of the piston 30 at the various steps in the forming process. From the funnel 87, which is in the layer shown in Fig. 4, and SO blow c. During the filling of the mold, air pockets and irregularities may arise, and to remove these air pockets, irregularities, fiber orientation, etc. a device consisting of a crosspiece 90 and a series of vertical fingers 91 is lowered into the slurry in the mold, either simultaneously with the downward movement of the piston 30 or otherwise since the bottom of the piston has its lowest layer. This device, when lowered to its lowest layer, oscillates around its vertical axis to move the fingers 91 horizontally in the slurry. Such a movement in the slurry completely eliminates air pockets and irregularities, which have arisen during the holding, as well as Liven's other harmful conditions.

Each lamp device can be used for these vertical and horizontal movements, such as a cylinder 95 for the vertical movement and a rack 96, a gear 97 and a cylinder 98 for the horizontal movement.

Starting from the expulsion stroke b of the piston 30, the inlet is introduced under pressure in the chamber 15, as indicated at d, and to the inside of the crank 45 to preheat the cradles in the mold 10 and the crank 45, whereby the slurry comes into contact with heat immediately when the piston Sucks it down into the mold 10. Thus, no time elapses between the filling of the mold and the application of heat to the slurry.

After the mold has been filled by the downward stroke of the piston 30, the lid 55 is placed in a layer on the hardener 11 yid e and read in this layer with the bayonet glass 58. The solenoid-operated valve 69 is opened, allowing water under relatively low pressure to flow through the conduit 68 into the chamber 57. as Midas of the lid 55 in its position Over the form 10, as indicated at f. the exposed surface of the slurry is brought under sufficient pressure to prevent rapid boiling when the high temperature rapidly falls during the cycle. The tube, previously sealed, as mentioned above, flows in through the tubes 20 in the chamber 15 between the side cradles of the mold 10 and the inner cradles of the hardener 11 through the valve 61, which also snaps into the conduit 50 to heat the core 45. The time during which depending on the density of the final product, the initial temperature of the slurry as it is fed, the mold thickness of the final product and the type of reactive components of the slurry are fed. If e.g. the rock thickness is 7.5 cm and the desired density: in the final product is about 0.18 g / cm3 and the slurry mainly consists of the reaction-prone lime and silicic acid and the silicic acid is present in the form of quartz and diatomaceous earth and an accelerator such as sodium hydroxide and water are added. a time of about 25 minutes per 2.5 cm thickness is normally required to cure such a slurry to a point or to such an extent that it can only lose its own weight without falling solidly when removed from the mold.

Asbestos, either finely divided or in long fiber form or bath adder, can be used in all of these slurries for various desired benefits and purposes.

When the desired degree of hardening is reached, the inlet to the chamber 15 is aistanged by means of the valve 61, as at h, and the inlet is replaced, as in the j 56 dr arranged in the chamber 57 for spreading the coolant in the chamber 57, which may be constituted by compressed air and / or water over the upper part of the molded product in order to prevent local disturbances or cooling thereof. The water fed into the chamber 15 rapidly cools the inner rocks of the mold 10 and thereby the present product. After a short time, the temperature of the solid substances which form the product, and part of it enclosed, the free water has fallen below the boiling point, 100 ° C at atmospheric pressure, and the possibility of boiling in or rupturing the product is avoided by the combination of air and water under pressure in the chamber 57. . When using higher pressures, however, it is a matter of course that such pressures must be regulated before the cover 55 is removed.

When removing the cover 55, the valve 86 can be actuated by means of a cam or an electromagnet or other device, so that - - compressed air from the main line 80 and 85 is introduced into the cylinder 33 through the line 82 to feed the gear 44 upwards and by means of the gears 41 and 42 the piston 30 upwards, as yid b, and push out or eject the shaped product. This piston 30 remains in its upper layer A and cooperates with the hopper 87 on the next filling of the mold 10. Immediately when the piston 30 begins the pushing stroke or something before that, any entry is made into the chamber 50, as at d, to preheat the side cradles of the mold 10. , before it receives the next charge. The funnel 87 is filled any ° while it is Over the form 10, the valve 86 is rearranged so that air is supplied to the line 83 and thus the upper end of the cylinder 33 to move the piston 30 downwards, as at c, and thereby draw slurry from the funnel 87 into the mold 10 by means of the suction generated by this non-extending stroke of the piston. In this case, the time interval, which would normally be lost for production purposes, between two cycles is fully utilized. In other words, during the time beginning with the removal of the previously molded product, the funnel 87 is applied over the opening of the mold and filled with a large amount of slurry. The cradles 10 of the mold 10 are preheated to operating temperature before the next batch of slurry is introduced, so that the time which would normally be required for subsequent heating of the cradles of the mold and the charge itself, after being introduced into the mold 10, is reduced to a minimum. Through such work, thanksgiving is obtained between the steps in the cycle, which allows increased production capacity in yarje form saint even more stable dimensions of the stud product. The shaping process is then repeated anyo in the manner described above.

The inhalation of a combination of air and water under pressure makes it possible to reduce the size of the entrapped air bubbles in the slurry to a minimum. In other words, this pressure not only reduces the size of any entrapped air bubbles but also holds them down, until the material has hardened or reacted to such hardness, since the blisters no longer cause harmful changes in the structure of the product. When this pressure ceases to affect the solidified product, the entrapped air passes out of the product without affecting its structure on any salt. The pressure can be reduced only by inhaling water under a pressure of about 2.1 kp / cm2, whereby equally good results are obtained.

Maintaining the air-water pressure in the chamber 57 prevents water in the preformed product from boiling, which would occur if the pressure were rapidly released, while the temperature of the product is sufficiently high and above the corresponding boiling point of the water at the reduced pressure. One side boiling would cause enlargement of the product and in some cases an explosive enlargement due to the sudden boiling of the water in the hardened product.

When the temperature of the product reaches a point at night which is at least below the boiling point of water at atmospheric pressure, the valve 69 is closed and the valve 71 is opened to the outside air, after which the lid 55 is removed, while immediately afterwards the piston 30 moves upwards and projects the shaped product. The water to chambers 15 and 45 is shut off and replaced with steam to begin the next forming process.

Claims (13)

Patent claims: 1. Placed hard silicate slurries in water for the production of lubricating, porous silicate molds, can be explained by the fact that the slurry is introduced into a preheated mold, because a medium under pressure may affect the surface of the slurry in the filling opening of the mold, that the slurry is hardened by heating , that the hardened molding is cooled by passing a coolant towards the cradles of the mold, that the pressure 'Dyad & the slurry surface in the filling opening of the mold is relieved, and that the water which has been separated at the top is drained and the molding is removed. 2. Set according to patent claim 1, characterized in that the mold is loaded with a preheated slurry. 3. Set according to claim 2, characterized in that a slurry is preheated to between 66 and 100 ° C. 4. According to patent claims 1-3, it can be seen that a slurry is used which has a weight-related water-solids content from 0.75: 1 to 7: 1. 5. Set according to any one of the patent claims 14, characterized in that entering with a temperature of more than 100 ° C and with a pressure of at least 1.1 kp / cm 2 was used for heating the mold cracks, while water was used for cooling the latter, and that the water under pressure ay preferably 4.2 kp / cm2 is allowed to act on the surface of the slurry in the filling opening of the mold. 6. Set according to claim 5, characterized in that moisture-saturated air is allowed to act on the surface of the slurry in the patillation opening. 7. Set according to any one of patent claims 1-6, characterized in that the mold is filled by sucking the slurry therein. 8. Set according to any one of patent claims 1-7, characterized in that the water present in the filling opening above the suspension in the filling opening is at a pressure which exceeds the pressure at the temperature of the slurry. 6— - Shit according to any one of claims 1-8, characterized in that the slurry is stirred in the hardening mold. 10. A sheet according to any one of claims 1-9, characterized in that during continuous operation the mold is preheated already during the ejection of the molding. Device for carrying out the sheet according to claims 1-10, characterized in that a mold (10) for producing silicate molds Sr is surrounded by a jacket (11), which is insulated from the filling opening of the mold and forms an vapor chamber (15), while The filling fitting is provided with a lid (55), which over the opening forms a sludge chamber (57) separated from the dung chamber (15), and that the steam chamber (15) is provided with supply lines (20, 21, 62; 23, 24) and leads ( 25, 26, 27) for steam and coolant, and the sludge chamber Sr is provided with a fill line (68) independent of the steam chamber for a medium under pressure. Device according to patent claim 11, characterized by a feeding device (87), which in the position of the lid (12) is arranged on. the form. Device according to patent claim 11, characterized by a stirrer (90, 91), which is arranged to be inserted into and removed from the mold by means of a piston or servomotor (95). Device according to claim 11, characterized in that the lid (55) can be locked to the mold by means of a welding device (58). Device according to claim 11, jug-drawn drive gear, for a tubular body 45 (45), provided with tubular bodies in the mold, is provided with tubes (48, 49, 52, 65) for supplying cooling and heating media to the interior of the core. and for the diversion of the said media Iran karnan. 4. Device according to patent claim 11, characterized in that the bottom of the mold is formed as a piston (30) which, when moved upwards, projects the molding and, when moved, does not suck in the charge of the mold. Request publications: