DE2428312A1 - Foam breaker external to a reactor - using centrifuge discs in a small vessel, esp. for fermentation vats - Google Patents

Abstract

Foam formed in a reaction vat is broken by a centrifugal foam breaker mounted in a smaller vessel above the vat. The foam is transferred by a pipe with side entry to the small vessel and the gas leaves via the hollow shaft of the centrifuge. Esp. for use in fermentation vats. The main vat can be filled to greater capacity than if the separator was mounted in it. There is less chance of contamination and the equipment is easier to maintain.

Description

Device for foam destruction II Addendum to patent application P 23 45 374.9 In the patent application P 23 45 374.9 a device for destruction of foam in reaction vessels to be gassed, e.g.

in fermenters, described, which was characterized in that one Above the reaction vessel, a smaller vessel in relation to the reaction vessel attaches, via a side supply line and a discharge line at the bottom of the vessel is connected to the reaction vessel, through its removable cover the hollow axis a centrifugal foam separator, from which an exhaust air duct into the open air goes.

The discharge at the bottom of the smaller vessel ends after passage through the lid of the reaction vessel above the liquid level.

To improve the device according to patent application P 23 45 374.9 the return pipe coming from the auxiliary container 2 is discharge line 3, through which the liquid reaction medium or the concentrated heavy foam to the reaction vessel 11 flows back, if extended, until it is in the liquid reaction medium dives.

An arrangement of the improved device is particularly useful, in which the end of the return pipe discharge line 3 is bent and the opening in Shows the direction of the moving liquid reaction medium.

In the chemical industry, especially in the fermentation industry, The reaction media must be moved frequently during the reaction in order to ensure thorough mixing to reach. In addition to stirring, the liquid reaction medium is gassed, i.e. it is Air blown through. This creates foams, which are caused by the discharge of the air lead to more or less severe fluid losses.

It is possible that foam formation is caused by surface-active substances to be reduced, but such substances are not always in any desired amount can be used because they lead to contamination of the reaction products and the chemical Inhibit reaction, which is particularly important in the fermentation industry plays.

For this reason, foam destroyers have been developed in recent years, which work according to the method of separation by centrifugal forces. These centrifugal foam destroyers are attached below the lid of the reaction vessels and generate in their Surrounds a low-foam zone.

However, this arrangement suffers from a number of disadvantages.

The centrifugal foam breaker requires a not inconsiderable one Space between the bottom of the lid and the surface of the liquid to work effectively to be able to. In addition, the larger the fermenter size, there must be an increasing one Safety distance should be provided because in the more or fewer Strongly stirred and aerated liquids, bulges or splash phenomena appear. This space in the reaction vessel cannot therefore be used as a reaction space.

The centrifugal foam destroyer is driven by an axis with a seal. Seals such as stuffing boxes or mechanical seals are however, susceptible to wear and tear, which easily creates the risk of contamination of the reaction medium can occur from the outside.

The liquid contact of the plates causes them to be so strong be braked that an overload of the electrical and mechanical drive system occurs, which for automatic shutdown and corresponding foam or liquid consumption lust leads.

The invention is based on the object of overcoming these disadvantages.

The object of the invention is achieved in that one above the reaction vessel 11 attaches a smaller vessel 2 in relation to the reaction vessel, that over a side Feed line 1 and a discharge line 3 on the floor of the vessel, the end of which is immersed in the liquid reaction medium, with the reaction vessel 11 is connected, through the removable cover 6, the hollow axis of a centrifugal foam separator 5 leads, from which an exhaust air line 7 goes outside.

A special embodiment of the device according to the invention consists in the fact that the discharge line 3 is at the end which leads into the liquid reaction medium dips, is bent and the opening in the direction of the moving liquid reaction medium shows.

To control the operation of the device according to the invention it is It is expedient that the smaller vessel 2 is provided with peep holes 4 on the side and a sensor 8 is introduced into the exhaust air line 7.

The inventive device has the advantage that in addition to one effective foam destruction, an increased throughput per batch due to a higher filling height in the reaction vessel and a reduced risk of contamination by keeping the Foam of the fermenter stirrer lead-through, the device in the event of malfunctions and a repair is easily accessible, because thus only an auxiliary unit and not the actual reaction vessel must be opened.

The device according to the invention is shown in the following figure 1 explained.

The air outlet pipe leads from the stirred reaction vessel (11) to be gassed Feed line (1) to the auxiliary container (2), the feed line (1) advantageously divided and brought close to the gland (10) of the stirrer shaft (9) will. The auxiliary tank (2) has the return pipe discharge line (3) at its bottom, through which the liquid reaction medium or the concentrated heavy foam to Reaction vessel (11) flows back. The lower end of the lead (3) dips in the liquid reaction medium, wherein the part of the discharge line (3), which in the liquid Reaction medium dips, is bent. and the opening in the direction of the stirred or moving reaction medium shows.

The foam destroyer is on the removable cover (6) of the auxiliary container (2) (5), which prevents the foam from flowing into the exhaust air line (7) leading into the Free leads, prevents. An electrode (8) is inserted into the exhaust air line (7), which causes the foam destroyer (5) to switch on as soon as foam enters the exhaust duct (7) arrives.

The transfer of the foam into the auxiliary container (2) can through the Sight glasses (4) are observed.

Claims (2)

Claims 1. Further training of the device for destroying foam in Reaction vessels to be gassed, preferably fermenters, according to patent application P 23 45 374.9, characterized in that above the reaction vessel (11) a smaller vessel (2) in relation to the reaction vessel, which has a lateral supply line (1) and a discharge line (3) at the bottom of the vessel (2) with the Reaction vessel (11) is connected and immersed in the liquid reaction medium by its removable cover (6) the hollow axis of a centrifugal foam separator (5), from which an exhaust air line (7) goes outside. 2. Apparatus according to claim 1, characterized in that the end the discharge line 3, which is immersed in the liquid reaction medium, is bent and the Opening in the direction of the moving liquid reaction medium shows.