Valve with umbilicus for painting by hydraulic spraying of construction materials.

Ungur, Petru ; Pop, Petru ; Ungur, Patricia 等

1. INTRODUCTION

The thermo and phonon-absorbent construction materials has used in construction industry and installations for obtained thermal insulations, due to reducer of fuel and electrical energy, by diminished heat loss, vibration and noise.

The construction materials as plated [alpha]-plaster of panels and ceilings, or aerial bindings of [alpha]-plaster, with great absorbent capacity of sound, because of have many openings and great pores. By passing the sound wave through pores, it has subjected more repeated reflections with walls due to dumping.

A main problem of these products of gyps, regyps, etc. is them painting. It has well known that at these materials normal spraying with air jet did not assure a good adhesion of film, due to exfoliation and exfloration of paint. A way to avoid these defects is using painting by hydraulic spraying, characterized as a large deposition. In paper has presented a special valve construction, which favoured the smooth mixture of pigments with fillers and binding materials, eliminated separation in layers, because of density difference for every pigment [Constantinescu, 1979; Veteleanu, 2000].

The advantage of this valve consists in that did not change the paint colour, because of smooth mixture of paint's components into a special mixed room with core of rotated hyperboloid or frustum of a cone.

2. THEORETICAL FUNDAMENTALS

Application of film forming materials from hydraulic spraying consists in them dispersion in minute particle with a paint installation by spraying without air and them engaged on surfaces of painting [Math Encyclopedia, 1980].

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In hydraulic spraying process a great importance, have scalar fields as temperature and density of paint, represented by level surfaces. The scalar field or scalar function of time represented a correspondence between every point P(x,y,z), respectively every position vector from certain range its conferred a scalar [phi](x,y,z)=[phi]([GAMMA]). The fields have represented intuitive by surfaces [phi](x,y,z)=ct., named level surfaces in space or plan by level lines- [phi](x,y)=ct.

The scalar functions, as same lines of altitude and density are level lines [Math Encyclopedia, 1980]:

[phi](x,y,z) = [phi](r) (1)

[phi] (x,y) = ct. (2)

In construction of valve spraying under hydraulic pressure, for obtaining a smooth mixture of paint before spraying has used level surfaces and gradient. Ones of them are revolution surface, which has named umbilicus, presented in Fig.2. The umbilicus is a surface of revolution level, which has covered with an orthogonal network of meridians and parallel circles. The normal's-n of surfaces, along a parallel circle formed by regular points created a frustum of a cone. At a special valve the rotation cone has degenerated in a rotated hyperboloid or frustum of a cone, around of them by revolution in a special room, smoothing the spray paint, and get out by a special clearance-umbilicus [Math Encyclopedia, 1980].

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grad [phi] = [partial derivative][phi]/[partial derivative]x i + [partial derivative][phi]/[partial derivative]y j + [partial derivative][phi]/[partial derivative]z k (3)

For the function [phi]=[phi](r)=[phi](x,y,z) the variation-d[phi] a function-[phi], for:

dr = dxi + dyj + dzk (4)

,is:

d[phi]= [partial derivative][phi]/[partial derivative]x dx + [partial derivative][phi]/[partial derivative]y dy + [partial derivative][phi]/[partial derivative]z dz (5)

This expression can be sight as a dot product between vector-dr and vector-grad[phi] , given by relation (3). The function variation by position vector variation-dr would be:

d[phi] = grad [phi] x dr (6)

If it is choose direction-dr, so that dr to be level surface [phi]=ct, than [phi] did not change d[phi] = 0, or vector-grad[phi] is perpendicular on level surfaces [phi] = ct.

An application of level surfaces and gradient represents a construction of valve with hydraulic spraying, used at spraying without air of construction materials under form of panels, plates and ceilings from plaster with add of cellulose, expandable polystyrene, pearlite, phonon-absorbents. The smooth paint in special room of valve has made without mass loss, divergence of scalar field, named solenoid being zero.

div a = [partial derivative]u/[partial derivative]x + [partial derivative]v/[partial derivative]y + [partial derivative]w/[partial derivative]z = 0 (7)

The total mass loss for a finite range-G has calculated by volume integration-[integral][integral][[integral].sub.G] divad[tau]. This mass has flow by boundary-S of range-G. The expression in Gauss theorem components is:

[integral][integral][[integral].sub.G]([partial derivative]u/ [partial derivative]x + [partial derivative]v/[partial derivative]y + [partial derivative]w/[partial derivative]z)d [tau]=[integral][[integral].sub.S][ucos(x,n) + v cos(y,n) + w cos(z,n)] (8)

This theorem is available for example of revolution body, type umbilicus, used at paint valve, valve body being with surface-G simple connected and Gauss boundary-S with normal-n, continuing on surface. Thus, this valve is an application of transformation's volume integration in a surface integration. It has resulted that for a range with div a=0 the total flux is zero on boundary range.

3. VALVE FOR SPRAY PAINTING WITHOUT AIR

The proceeding of construction materials painting by spray without air is modern film forming materials has done by a hydraulic pump at high pressure [Secasiu, 1970; Tarina, 1982].

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Behind friction with air, the speed of minute particles paint is decrease, due to a slow lay of them on painted part, avoided the possibility of rebound and forming of oil mist as spraying with compressed air. At this proceeding the productivity is higher, realized a paint economy. The quality painting is higher, avoided exfolier and exflorer at panels, ceilings of phonon-absorbent materials by [alpha]-plaster [Gordan, 2006; Ungur, 2007].

In Fig.4 has presented a diagram flow of spaying without air, where: 1,4-are pumps, 2-tap, 3-filter, 5-heating element, 6-tap, 7-valve of air exhausted, 8-vessel with paint, 9-spray gun with special valve The tests had done at Congips Co. for painting of tiles and phonon-absorbent panels, which it was a success.

The valve spraying with umbilicus has presented in Fig.5, where: 1-body with tubular cavity and central tapering core, 2-cover with umbilicus, 3-support of fixing, a-umbilicus, b-curved surface, c-pin, d-thread, e-tub, and f-core.

The concept of valve with umbilicus can be used more that at painting, at sprinkle by hydraulic pump.

4. CONCLUSIONS

From special construction of valve of painting by hydraulic spray with room of mixed has assured a great smooth of paint.

Spraying delicacy is emphasized by select form of fit through is get out the liquid (umbilicus).

The valve presented its assured the tendency of paint jet transformation in a fascicle of minute sprayed particles.

The construction of valve is easy to build up, assured a higher quality of paint and large using in future.

5. REFERENCES

Constantinescu, M. (1979), Anticorrosive Protection of Metals, pp. 106-109, Technical Editor, Bucharest

Gordan, M.; Ungur, P. & Fodor, M.D. (2006), An Application of the Gauss Divergent them to the Exhusted Gates, 13th Conference on Applied and Industrial Mathematics, KAIM 2006, Oct.14-16, pp.49-50, ISBN 9975-7859-1 Pitesti, Romania

Secasiu, I. et al. (1970), Paint Handbook, pp. 245-247, Didactical and Pedagogical Editor, Bucharest

Tarina, A. et al. (1982), Book Operator in Lacquer and Paint Industry, pp. 286-291, Technical Editor, Bucharest

Ungur, P; Pop, P.A. Gordan, M. & Muresan, N. (2007), Optimal Construction of Hydraulic Pump with Elliptic Rotative Piston by Kakeya-Besikovitch Application, ASME International Design Enginnering Technical Conference, Computers and Information Engineering, Sept.4-7, 2007, Las Vegas, Proceeding ofDETC2007, pp.1-8, ISBN 0-7918-3806-4, ASME International, USA

Veteleanu, A. & Olaru, S. (2000), Anticorrosive Protection of Metals, pp. 142-144, Expires Editor, Brasov

*** (1980), Small Mathematical Encyclopedia, Translated by Ostelnicu, V & Coatu after Kleine Enzyklopadie Der Mathematic, 6th Edition, pp. 245-246, 590-595, Technical Editor, Bucharest.