SU1206495A2 - Diffusion pump - Google Patents

Description

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The invention relates to vacuum technology and is an improvement of the diffusion pump according to the author. St. No. 1030583.

The aim of the invention is to reduce the amount of reverse flow during the pump start-up period.

The drawing shows the proposed pump, a longitudinal section.

The diffusion pump includes a housing 1, a steam line 2 located therein with a nozzle formed by an umbrella 3 and a tiller 4, a impeller 5 located in the steam line 2 and a shaft on which an umbrella 3 and an impeller 5 are mounted, the shaft being made of two parts 6 and 7, interconnected by means of a movable spline joint 8. One shaft part 6 is provided with a bore 9 and an end partition 10 that overlaps it with a central hole, and the other with a rod 11 inserted into the bore 9 through a partition 10 hole and spring-loaded tnositelno latter, by a spring 12.

The pump works as follows

The vapors of the working fluid, lifting along the steam line 2, drive the impeller into rotation. 5 and together

Compiled by O. Tishina Editor O. Yurkovetska Tehred O. Niece Corrector V. Sinitska

Order 8677/36 Circulation / 8 / Subscription

VNIIPI State Committee of the USSR

for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5

Branch ShSh Patent, Uzhgorod, Proektna St., 4

064952

with it an umbrella 3. during the start-up period, when the vapor pressure in the steam line 2 is low, the umbrella 3 is in the lower position, excluding the release of working fluid vapor from the nozzle and at the same time the reverse flow of working fluid vapor into the pumped-out volume. And only when the pressure in the steam line 2 is reached, which corresponds to the critical pressure ratio (the ratio of the pressure Pj at the nozzle exit to the pressure Pc at the nozzle entrance Pg / P at which the flow rate becomes maximum and with a further decrease

The pressure tS behind the nozzle Pe does not change, is called the critical pressure ratio, the steam pressure in the steam line 2 overcomes the force of the spring 12, the latter is compressed, and the umbrella 3,,

20 coupled through the spline connection 8 and the rod 11 with the spring 12, moving away from its original position, the nozzle opens. Wherein . critical is immediately established

25, the pressure ratio before and after the nozzle, and the steady state flow regime sets in.

When the pump stops as the pressure in the steam line decreases

30 and under the action of the spring, the umbrella is lowered and the nozzle is closed.

Claims (1)

DIFFUSION PUMP by ed. St. No. 1030583, characterized in that, in order to reduce the amount of reverse flow during the start-up of the pump, one part of the shaft is provided with a bore and an end partition blocking it with a central hole, and the other with a rod inserted into the bore through the partition hole and spring-loaded SU, 1206495 eleven